TY - CONF AU - Rossi, L. AU - Brüning, O.S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Progress with the High Luminosity LHC Project at CERN J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The High Luminosity LHC (HL-LHC) project aims at upgrading the LHC by increasing the peak luminosity by a factor five, to allow to collect 3000 fb-1 for ATLAS and CMS experiments, each, which is ten times more than what is foreseen in the LHC. The upgrade is based on multiple factors. One factor is doubling the beam current, also thanks to the injector upgrade (LIU) project, and another one is operation in levelling mode. The most critical upgrade is the deploying of a stronger inner quadrupole triplet in the low-beta insertions with more than twice-larger aperture w.r.t. present LHC triplet, thanks to the use of Nb₃Sn superconductor, a world first for accelerators, with almost 12 T peak field in the coils. The novel concept of ATS optics allows to utilise the increased aperture efficiently by generating β^{*} values 3 to 4 times below the nominal values of the LHC. We will make use of compact crab cavities for hadrons (also a novelty in accelerators) to allow almost head-on collisions despite the larger crossing angle. We are developing new collimator insertions in the dispersion suppressor region to handle the losses in the cold part of the machine (the beam halo stores 30 MJ) thanks to the use of a few 11 T dipoles based on Nb₃Sn technology. We also aim at reducing drastically the impedance contribution of collimators by utilizing new materials and coating techniques. Many other technologies are developed for HL-LHC like new SC links of 100 kA: HL-LHC is critical as a technology turning point for HEP colliders as it is for Physics reach. The technologies developed for HL-LHC, namely (but not only) the high field superconducting magnets, are critical for the post-LHC hadron collider, like a High Energy LHC or the 100 km Future Circular Collider PB - JACoW Publishing CP - Geneva, Switzerland SP - 17 EP - 22 KW - luminosity KW - cavity KW - operation KW - quadrupole KW - collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOYPLM3 UR - http://jacow.org/ipac2019/papers/moyplm3.pdf ER - TY - CONF AU - Pugnat, T. AU - Bonaventura, L. AU - Dalena, B. AU - De Maria, R. AU - Olsen, V.K.B. AU - Simona, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Study of Fringe Fields Effects from Final Focus Quadrupoles on Beam Based Measured Quantities J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Accelerator physics needs advanced modeling and simulation techniques, in particular for beam stability studies. A deeper understanding of the effects of magnetic fields non-linearities will greatly help in the improvement of future colliders design and performance. In *, a new tracking method was proposed to study the effect of the longitudinal dependency of the harmonics on the beam dynamics. In this paper, the study will focus on the effects on observable quantities in beam based measurements, for the case of HL-LHC Inner Triplet and with possible tests in LHC. PB - JACoW Publishing CP - Geneva, Switzerland SP - 90 EP - 93 KW - quadrupole KW - multipole KW - optics KW - dynamic-aperture KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW012 UR - http://jacow.org/ipac2019/papers/mopgw012.pdf ER - TY - CONF AU - El Khechen, D. AU - Oide, K. AU - Zimmermann, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Beam-Beam Blowup Issue After Low Emittance Tuning for FCC-ee J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - FCC-ee (Future Circular Collider) is a 100 km electron-positron circular collider with two foreseen experiments, aiming to run at four energies for precision studies of the Z, W, and Higgs boson and the top quark. The FCC-ee is a challenging machine from different points of view. In particular the beam-beam effects are of great importance. For the FCC-ee high-luminosity operation, the beam-beam effects impose profound constraints on the operating point in betatron tune space. In addition, taking into account different sources of machine nonlinearities, a tracking simulation with beam-beam elements revealed a strong beam blowup, especially in the vertical plane. Such a blowup is a potential obstacle to achieving and maintaining a high luminosity; therefore it needs to be carefully studied. In this paper, we present a general overview of simulation results on the FCC-ee beam-beam blowup with realistic machine errors. PB - JACoW Publishing CP - Geneva, Switzerland SP - 112 EP - 115 KW - emittance KW - lattice KW - simulation KW - optics KW - coupling DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW019 UR - http://jacow.org/ipac2019/papers/mopgw019.pdf ER - TY - CONF AU - Sapinski, M. AU - Geithner, O. AU - Heßler, C. AU - Reimann, S. AU - Schütt, P. AU - Vossberg, M. AU - Walasek-Höhne, B. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Measurements of the GSI Transfer Beam Lines Ion Optics J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - GSI High Energy Beam Transfer lines (HEST) link the SIS18 synchrotron with two storage rings (Experimental Storage Ring and Cryring) and six experimental caves. The recent upgrades to HEST beam instrumentation enables precise measurements of beam properties along the lines and allow for faster and more precise beams setup on targets. Preliminary results of some of the measurements performed during runs in 2018 and 2019 are presented here. The focus is on response matrix measurements and quadrupole scans performed on HADES beam line. The errors and future improvements are discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 131 EP - 134 KW - quadrupole KW - extraction KW - experiment KW - emittance KW - storage-ring DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW024 UR - http://jacow.org/ipac2019/papers/mopgw024.pdf ER - TY - CONF AU - Lin, X. AU - Chen, H.B. AU - Liu, Z.N. AU - Shi, J. AU - Wu, X.W. AU - Zha, H. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Analysis and Simulation of the "After-Pulse" RF Breakdown J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - During the high power experiment of a single-cell standing-wave accelerating structure, it was observed that many RF breakdowns happen when the field inside cavity is decaying after the input rf pulse is off. The distribution of breakdown timing shows a peak at the moment of RF power switches off. A series of simulation was performed to study the after-pulse breakdown effect in such a standing-wave structure. A method of calculating poynting vector over time is proposed in this article to study the modified poynting vector at critical points in the cavity. Field simulation and thermal simulation were also carried out to analyse possible reasons for the after-pulse breakdown effect. PB - JACoW Publishing CP - Geneva, Switzerland SP - 196 EP - 199 KW - cavity KW - simulation KW - timing KW - GUI KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW047 UR - http://jacow.org/ipac2019/papers/mopgw047.pdf ER - TY - CONF AU - Bartosik, H. AU - Alemany-Fernández, R. AU - Argyropoulos, T. AU - Bohl, T. AU - Damerau, H. AU - Kain, V. AU - Papotti, G. AU - Rumolo, G. AU - Saá Hernández, Á. AU - Shaposhnikova, E.N. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Recent Beam Performance Achievements with the Pb-Ion Beam in the SPS for LHC Physics Runs J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the SPS, which is the last accelerator in the LHC ion injector chain, multiple injections of the Pb-ion beam have to be accumulated. On this injection plateau the beam suffers from considerable degradation such as emittance growth and losses. This paper summarises the achievements on improving the beam parameters and maximising the performance of the Pb-ion beam for the LHC physics run in 2018. The results are discussed in view of the target beam parameters of the LHC injectors upgrade project, which is being deployed during the presently ongoing long shutdown. PB - JACoW Publishing CP - Geneva, Switzerland SP - 250 EP - 253 KW - injection KW - target KW - optics KW - luminosity KW - flattop DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW069 UR - http://jacow.org/ipac2019/papers/mopgw069.pdf ER - TY - CONF AU - Argyropoulos, T. AU - Lasheen, A. AU - Quartullo, D. AU - Shaposhnikova, E.N. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Longitudinal Stability of the Hollow Ion Bunches After Momentum Slip-Stacking in the CERN SPS J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Momentum slip-stacking is planned to be used for the lead ion beams in the CERN SPS to double the beam intensity for the High-Luminosity LHC project. During this RF manipulation two SPS batches, controlled by two independent RF systems, are going to be interleaved on an intermediate energy plateau, reducing the bunch spacing from 100 to 50 ns. However, there are limitations how close the frequencies of two RF systems can approach each other, resulting in a hole in the longitudinal bunch particle distribution due to the offset in energy of the recaptured bunches. After filamentation, these bunches should be further accelerated to the SPS top energy, before extraction to the LHC. Macro-particle simulations have shown that Landau damping is lost for the bunches with the smallest longitudinal emittances in the batch, causing un-damped oscillations of the bunch core after recapture. The standard application of an additional, fourth harmonic RF system, successfully used in proton operation, was not able to damp the oscillations at top energy, while it was necessary to switch it on from the moment of recapture. In this paper the longitudinal stability of the bunches after slip-stacking is studied in more details both by macro-particle simulations and analytical calculations. PB - JACoW Publishing CP - Geneva, Switzerland SP - 254 EP - 257 KW - simulation KW - emittance KW - damping KW - synchrotron KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW070 UR - http://jacow.org/ipac2019/papers/mopgw070.pdf ER - TY - CONF AU - Arominski, D. AU - Latina, A. AU - Schulte, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Resistive Wall Effects in the CLIC Beam Delivery System J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Resistive wall wakefields are an important issue to study for future linear colliders. Wakefields in the Beam Delivery System (BDS) might cause severe multi-bunch effects, leading to beam quality and luminosity losses. The resistive wall effects depend on the beam pipe apertures and materials, which are optimised to limit the impact on the beam. This paper presents a study of this problem for the 380 GeV and 3 TeV beam parameters and optics of the Compact Linear Collider’s BDS. First, the optimisation of the beam pipe apertures to limit the impact of resistive wall effect on the beam quality is shown, then the luminosity and its quality are presented. Finally, the proposed design parameters are discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 258 EP - 261 KW - luminosity KW - wakefield KW - collider KW - vacuum KW - feedback DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW071 UR - http://jacow.org/ipac2019/papers/mopgw071.pdf ER - TY - CONF AU - Bartosik, H. AU - Carlà, M. AU - Cornelis, K. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Reconfiguration of SPS Landau Octupole Circuits to Minimise Second Order Chromaticity J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the SPS Q20 optics presently used for LHC beams, the Landau octupole families of the SPS (LOF and LOD circuits) generate large second order chromaticity due to the relatively high dispersion at their locations. Since the induced second order chromaticity results in enhanced losses due to the large incoherent tune spread, these octupoles cannot be used for mitigating transverse instabilities for LHC beams. A new cabling scheme was proposed, exploiting additional octupoles that were already installed in the machine but not used, which allows minimizing the induced second order chromaticity in both the Q20 optics used for LHC beams, as well as the original SPS optics used for fixed target beams. This paper summarises the optics calculations as well as the experimental verification of the reduced chromatic detuning of the new octupole scheme. PB - JACoW Publishing CP - Geneva, Switzerland SP - 262 EP - 265 KW - octupole KW - optics KW - operation KW - target KW - acceleration DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW072 UR - http://jacow.org/ipac2019/papers/mopgw072.pdf ER - TY - CONF AU - Chmielinska, A. AU - Barnes, M.J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - New Spiral Beam Screen Design for the FCC-hh Injection Kicker Magnet J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The injection kicker system for the Future Circular Collider (FCC-hh) must satisfy demanding requirements. To achieve low pulse ripple and fast field rise and fall times, the injection system will use ferrite loaded transmission line type magnets. The beam coupling impedance of the kicker magnets is crucial, as this can be a dominant contribution to beam instabilities. In addition, interaction of the high intensity beam with the real part of the longitudinal beam coupling impedance can result in high power deposition in the ferrite yoke. This gives a significant risk that the ferrite yoke will exceed its Curie temperature: hence, a suitable beam screen will be a critical feature. In this paper, we present a novel concept - a spiral beam screen. The fundamental advantage of the new design is a significant reduction of the maximum voltage induced on the screen conductors, thus decreased probability of electrical breakdown. In addition, the longitudinal beam coupling impedance is optimized to minimize power deposition in the magnet. PB - JACoW Publishing CP - Geneva, Switzerland SP - 270 EP - 273 KW - kicker KW - impedance KW - injection KW - coupling KW - vacuum DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW074 UR - http://jacow.org/ipac2019/papers/mopgw074.pdf ER - TY - CONF AU - Kramer, P. AU - Farricker, A. AU - Vollinger, C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Verification by RF Measurements of New HOM Mitigation Scheme Developed for Future SPS 33-Cell Accelerating Structures J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Longitudinal higher-order modes (HOMs) at a frequency of around 630 MHz in the 200 MHz travelling wave RF structures currently limit the beam intensities in the CERN SPS to less than that required by the High Luminosity (HL-) LHC. In the framework of the LHC Injectors Upgrade (LIU) project, the performance of the already existing HOM damping scheme for these standing wave modes must be improved. This involves improving the existing HOM-couplers as well as the possible use of a new mitigation technique via the insertion of resonant posts in some cells of the multi-cell structures. The development of the new damping scheme has been performed using theoretical analysis of the cavity-coupler interaction in conjunction with full-wave electromagnetic (EM) field simulations. This contribution will show the verification of the improved HOM damping performance by measurements on a single section with 11 cells and on the future 33-cell structures. The parasitic impact of the damping scheme on the travelling wave fundamental passband (FPB) will also be presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 274 EP - 276 KW - HOM KW - damping KW - simulation KW - impedance KW - coupling DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW076 UR - http://jacow.org/ipac2019/papers/mopgw076.pdf ER - TY - CONF AU - Farricker, A. AU - Vollinger, C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Impedance Reduction in the CERN SPS Through Element Layout Optimisation J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The CERN accelerator complex is currently in its long shutdown while the LHC Injector Upgrade is being carried out. The upgrade of the SPS includes but is not limited to: the relocation of the beam dumping system, upgrade of the RF system, replacement of the electrostatic septa and impedance reduction. These major upgrades present an opportunity to perform additional impedance reduction in areas not normally modified due to the large amount of work being performed across the accelerator complex. In this paper, we look at the impedance minimization in the sections near the large aperture quadrupoles of the extraction regions in the CERN SPS. By optimizing the locations of existing equipment and the introduction of a new, more impedance optimised type of bellows, significant reductions in the beam-coupling impedance can be achieved. PB - JACoW Publishing CP - Geneva, Switzerland SP - 277 EP - 280 KW - impedance KW - coupling KW - extraction KW - cavity KW - quadrupole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW077 UR - http://jacow.org/ipac2019/papers/mopgw077.pdf ER - TY - CONF AU - Furuseth, S.V. AU - Buffat, X. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Change of Beam Distribution Due to Decoherence in the Presence of Transverse Feedback J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The effect of Landau damping is often calculated based on a Gaussian beam distribution in all degrees of freedom. The stability of the beam is however strongly dependent on the details of the distribution. The present study focuses on the change of bunch distributions caused by the decoherence of the excitation driven by an external source of noise, in the presence of both amplitude detuning and a transverse feedback. Both multiparticle tracking simulations and theoretical models show a similar change of the distribution. The possible loss of Landau damping driven by this change is discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 281 EP - 284 KW - feedback KW - simulation KW - octupole KW - damping KW - emittance DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW078 UR - http://jacow.org/ipac2019/papers/mopgw078.pdf ER - TY - CONF AU - Garcia-Tabares, A. AU - Skowroński, P.K. AU - Tomás, R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Optics Measurements in the CERN PS Booster Using Turn-by-Turn BPM Data J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - As part of the LHC Injector Upgrade Project the injection of the CERN PS Booster will be changed to increase intensity and brightness of the delivered beams. The new injection scheme is likely to give rise to beta beating above the required level of 5\% and new measurements are required. Achieving accurate optics measurements in PSB lattice is a challenging task that has involved several improvements in both hardware and software. This paper summarizes all the improvements that have been performed in the optics measurement acquisition system together with a brief summary of the first results obtained. PB - JACoW Publishing CP - Geneva, Switzerland SP - 285 EP - 288 KW - optics KW - injection KW - MMI KW - booster KW - software DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW080 UR - http://jacow.org/ipac2019/papers/mopgw080.pdf ER - TY - CONF AU - Gohil, C. AU - Blaskovic Kraljevic, N. AU - Burrows, P. AU - Heilig, B. AU - Schulte, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Measurements of Stray Magnetic Fields at CERN for CLIC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Simulations have shown that the Compact Linear Collider (CLIC) is sensitive to external dynamic magnetic fields (stray fields) to the nT level. Magnetic fields are not typically measured to this precision at CERN. Past measurements of the background magnetic field at CERN are limited. In this paper new measurements are presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 289 EP - 292 KW - klystron KW - site KW - proton KW - collider KW - dipole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW081 UR - http://jacow.org/ipac2019/papers/mopgw081.pdf ER - TY - CONF AU - Gohil, C. AU - Blaskovic Kraljevic, N. AU - Burrows, P. AU - Schulte, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Mitigation of Stray Magnetic Field Effects in CLIC with Passive Shielding J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Simulations have shown the Compact Linear Collider (CLIC) is sensitive to external dynamic magnetic fields (stray fields) to the nT level. Due to these extremely tight tolerances, mitigation techniques will be required to prevent performance loss. A passive shielding technique is envisaged as a potential solution. A model for passive shielding is presented along with calculations of its transfer function. Measurements of the transfer function of a promising material (mu-metal) that can be used for passive shielding are presented. The validity of passive shielding models in small amplitude magnetic fields is also discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 293 EP - 296 KW - shielding KW - feedback KW - collider KW - simulation KW - hadron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW082 UR - http://jacow.org/ipac2019/papers/mopgw082.pdf ER - TY - CONF AU - Karpov, I. AU - Shaposhnikova, E.N. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Longitudinal Coupled-Bunch Instability Evaluation for FCC-hh J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - High-order modes (HOM) of the accelerating rf structures and other machine elements, if not sufficiently damped, can drive longitudinal coupled-bunch instabilities (CBI). Their thresholds can be accurately obtained from macro-particle simulations using the detailed impedance model containing many different contributions. This method, however, is very difficult to apply for synchrotrons with a large number of bunches, as it is the case for the Future Circular hadron-hadron Collider (FCC-hh) with up to 10400 circulating bunches per beam. In this paper the semi-analytical approach is used for calculations of the instability thresholds during the acceleration cycle of the FCC-hh. As the result, we define requirements for the HOM damping that would be sufficient to prevent development of longitudinal CBI in the presence of weak synchrotron radiation damping. PB - JACoW Publishing CP - Geneva, Switzerland SP - 297 EP - 300 KW - impedance KW - emittance KW - cavity KW - HOM KW - synchrotron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW083 UR - http://jacow.org/ipac2019/papers/mopgw083.pdf ER - TY - CONF AU - Karpov, I. AU - Baudrenghien, P. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Beam Loading Compensation for the Future Circular Hadron-Hadron Collider (FCC-hh) J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The power consumption of the rf system can be minimised by optimising the cavity detuning and the loaded quality factor. In high-current accelerators, the presence of gaps in the filling results in a modulation of the cavity voltage along the ring (transient beam loading) and as a consequence a spread in the bunch parameters. In addition longitudinal coupled-bunch instabilities can appear, caused by the cavity impedance at the fundamental. Both issues can be mitigated by using an rf feedback around the amplifier and cavity, a technique used in many high intensity machines including the Large Hadron Collider (LHC). Compared to the LHC machine, the energy increase and the radiation loss for the Future Circular hadron-hadron Collider (FCC-hh) will be larger, resulting in a synchronous phase deviating significantly from 180 degrees. The solutions adopted for the LHC must therefore be revisited. This paper evaluates several beam loading compensation schemes for this machine. PB - JACoW Publishing CP - Geneva, Switzerland SP - 301 EP - 304 KW - cavity KW - beam-loading KW - hadron KW - collider KW - impedance DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW084 UR - http://jacow.org/ipac2019/papers/mopgw084.pdf ER - TY - CONF AU - Korysko, P. AU - Burrows, P. AU - Latina, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Intensity Dependent Effects in the ILC BDS J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The International Linear Collider (ILC) is an electron-positron collider being considered for the post-LHC era. Its Beam Delivery System (BDS) receives the beam from the main linac. This beam is then focused to the nanometer scale after going through collimators, beam diagnostic systems, strong magnets, etc. Effects such as wakefields due to resistive-wall, BPMs and collimators make the system very sensitive to the beam intensity. Understanding these effects is crucial in order to demonstrate that the nominal beam size at the Interaction Point (IP) can be reached in realistic scenarios. In this paper, results of the intensity dependence effects in the ILC BDS, simulated with PLACET, are presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 305 EP - 307 KW - wakefield KW - luminosity KW - collider KW - simulation KW - linear-collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW085 UR - http://jacow.org/ipac2019/papers/mopgw085.pdf ER - TY - CONF AU - Korysko, P. AU - Burrows, P. AU - Faus-Golfe, A. AU - Kubo, K. AU - Latina, A. AU - Okugi, T. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Intensity Dependent Effects at ATF2, KEK J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Accelerator Test Facility 2 (ATF2) at KEK is a prototype for the Final Focus Systems of the future e⁺e⁻ linear colliders, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC). In this paper both simulation and experimental results are presented with special emphasis on intensity-dependent effects. The importance of these effects is shown using the PLACET code and realistic ATF2 machine simulations (including beam jitter, misalignment, wakefield, Beam Based Alignment (BBA) correction, …). The latest experimental results are also presented, in particular the impact of the beam intensity on the beam size at the IP. PB - JACoW Publishing CP - Geneva, Switzerland SP - 308 EP - 311 KW - simulation KW - collider KW - linear-collider KW - wakefield KW - electron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW086 UR - http://jacow.org/ipac2019/papers/mopgw086.pdf ER - TY - CONF AU - Métral, E. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - GALACTIC and GALACLIC: Two Vlasov Solvers for the Transverse and Longitudinal Planes J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - GALACTIC and GALACLIC, two Vlasov solvers for the study, in the transverse and longitudinal plane respectively, of single-bunch coherent oscillation modes, were recently developed starting from the Vlasov equation and using a decomposition on the low-intensity eigenvectors, as proposed by Laclare and Garnier. The first Vlasov solver was used for instance to shed light on the destabilising effect of resistive transverse dampers and the second helped understanding the details of the mode-coupling behind some longitudinal microwave instabilities. Both theories are reviewed in detail, highlighting in particular the similarities and peculiarities of the two approaches. PB - JACoW Publishing CP - Geneva, Switzerland SP - 312 EP - 315 KW - impedance KW - synchrotron KW - resonance KW - simulation KW - coupling DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW087 UR - http://jacow.org/ipac2019/papers/mopgw087.pdf ER - TY - CONF AU - Métral, E. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - A Two-Mode Model to Study the Effect of Space Charge on TMCI in the "Long-Bunch" Regime J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Using a two-mode approach for the Transverse Mode-Coupling Instability (TMCI) in the ’short-bunch’ regime (where the mode-coupling takes place between the modes 0 and -1, such as in the CERN LHC), both a reactive damper (ReaD) and Space Charge (SC) are expected to be beneficial: the ReaD would shift the mode 0 up while SC would shift the mode -1 down, but in both cases the coupling (and related instability) would occur at higher intensities. However, the situation is more involved in the ’long-bunch’ regime (where the mode-coupling takes place between higher-order modes, such as in the CERN SPS). As the ReaD modifies only the (main) mode 0 and not the others, it is expected to have no effect for the main mode-coupling. As concerns SC, it modifies all the modes except the mode 0, and the result has been a subject of discussion for two decades. A two-mode approach is discussed in detail in this contribution for the case of a single bunch interacting with a broad-band resonator impedance in the ’long-bunch’ regime. This model reveals in particular that in the presence of space charge, the intensity threshold can only be similar to or lower than that in the absence of space charge. PB - JACoW Publishing CP - Geneva, Switzerland SP - 316 EP - 319 KW - coupling KW - space-charge KW - impedance KW - optics KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW088 UR - http://jacow.org/ipac2019/papers/mopgw088.pdf ER - TY - CONF AU - Métral, E. AU - Migliorati, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Longitudinal Mode-Coupling Instability: GALACLIC Vlasov Solver vs. Macroparticle Tracking Simulations J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Following the same approach as for the recently developed GALACTIC Vlasov solver in the transverse plane and taking into account the potential-well distortion, a new Vlasov solver, called GALACLIC, was developed for the longitudinal plane. In parallel, a new mode analysis was implemented for the post-processing of the results obtained through macroparticle tracking simulations. The results of the several benchmarks performed between the two methods are presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 320 EP - 323 KW - impedance KW - simulation KW - coupling KW - synchrotron KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW089 UR - http://jacow.org/ipac2019/papers/mopgw089.pdf ER - TY - CONF AU - Schwarz, M. AU - Lasheen, A. AU - Papotti, G. AU - Repond, J. AU - Shaposhnikova, E.N. AU - Timko, H. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Capture and Flat-Bottom Losses in the CERN SPS J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Particle losses on the flat bottom of the SPS, the last accelerator in the injector chain of the LHC at CERN, are a strong limitation for reaching the high intensities required by the high luminosity upgrade of the LHC. Two contributions to these losses are investigated in this paper. The first losses occur during the PS-to-SPS bunch-to-bucket transfer, since the bunch rotation in the PS creates halo particles and the bunch does not completely fit into the SPS RF-bucket. The effect of longitudinal shaving in the PS on the beam transmission was recently tested. At high intensities, further capture losses are caused by beam loading in the traveling wave RF system of the SPS, which is partially compensated by the LLRF system, in particular by one-turn delay feedback. While the feedforward system reduces the capture losses, it also increases the losses along the flat bottom due to the RF noise. PB - JACoW Publishing CP - Geneva, Switzerland SP - 327 EP - 330 KW - beam-loading KW - injection KW - emittance KW - impedance KW - feedback DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW091 UR - http://jacow.org/ipac2019/papers/mopgw091.pdf ER - TY - CONF AU - Carver, L.R. AU - Alekou, A. AU - Antoniou, F. AU - Appleby, R.B. AU - Bartosik, H. AU - Bohl, T. AU - Burt, G. AU - Calaga, R. AU - Carlà, M. AU - Levens, T.E. AU - Mitchell, J.A. AU - Papotti, G. AU - Welsch, C.P. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - First Machine Developments Result with HL-LHC Crab Cavities in the SPS J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Crab cavities are a critical component within the High Luminosity upgrade project for the Large Hadron Collider (HL-LHC). It is foreseen to use crab cavities in order to compensate the geometric luminosity reduction factor (reduction of the luminous region at the Interaction Point [IP]) due to the beam crossing angle (required for minimizing the impact of the long range beam-beam effects on the single particle beam dynamics) and increase the number of collisions per bunch crossing. In 2018 the first beam tests of crab cavities with protons were performed in the Super Proton Synchrotron (SPS) at CERN. Two vertical superconducting cavities of the Double Quarter Wave (DQW) type were fabricated and installed in the SPS to verify some key components of the cavity design and operation. This paper will present some of the first results relating to the proton beam dynamics in the presence of crab cavities. PB - JACoW Publishing CP - Geneva, Switzerland SP - 338 EP - 341 KW - cavity KW - proton KW - closed-orbit KW - luminosity KW - diagnostics DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW094 UR - http://jacow.org/ipac2019/papers/mopgw094.pdf ER - TY - CONF AU - Alekou, A. AU - Appleby, R.B. AU - Bartosik, H. AU - Carlà, M. AU - Papaphilippou, Y. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Beam Dynamics Simulations with Crab Cavities in the SPS Machine J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The LHC Upgrade, called High Luminosity LHC, aims to increase the integrated luminosity by a factor of 10. To achieve this, the project relies on a number of key innovative technologies, including the use of superconducting Crab Cavities with ultra-precise phase control for beam rotation. A set of prototype Crab Cavities has been recently installed in the second largest machine of CERN, the Super Proton Synchrotron (SPS), that operated as a test-bed from May to November of 2018. The tight LHC constraints call for axially non-symmetric cavity designs that introduce high order multipole components. Furthermore, the Crab Cavities in the presence of SPS non-linearities can affect the long term stability of the beam. This paper presents how the SPS dynamic aperture is affected for different cavity, machine and beam configurations. PB - JACoW Publishing CP - Geneva, Switzerland SP - 342 EP - 345 KW - multipole KW - cavity KW - simulation KW - luminosity KW - optics DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW095 UR - http://jacow.org/ipac2019/papers/mopgw095.pdf ER - TY - CONF AU - Boutin, D. AU - Chancé, A. AU - Dalena, B. AU - Holzer, B.J. AU - Schulte, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Optic Corrections for FCC-hh J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. The evaluation of the various magnets mechanical error and field error tolerances in the arc sections of FCC-hh, as well as an estimation of the required correctors strengths, are important aspects of the collider design. In this study the mechanical tolerances, dipole and quadrupole field error tolerances for the arc sections of FCC-hh are evaluated. The consolidated correction schemes of the linear coupling (with skew quadrupoles) and of the beam tunes (with normal quadrupoles) are presented. The integration of the different ring insertions (interaction region, collimation, injection, etc) is also discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 417 EP - 419 KW - quadrupole KW - injection KW - insertion KW - dipole KW - coupling DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP001 UR - http://jacow.org/ipac2019/papers/mopmp001.pdf ER - TY - CONF AU - Ogur, S. AU - Barnyakov, A.M. AU - Chaikovska, I. AU - Chehab, R. AU - Furukawa, K. AU - Iida, N. AU - Kamitani, T. AU - Levichev, A.E. AU - Martyshkin, P.V. AU - Miyahara, F. AU - Nikiforov, D.A. AU - Oide, K. AU - Ozcan, E.V. AU - Papaphilippou, Y. AU - Polozov, S.M. AU - Rinolfi, L. AU - Yaman, F. AU - Zimmermann, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Linac and Damping Ring Designs for the FCC-ee J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We report the design of the pre-injector chain for the Future Circular e⁺ e⁻ Collider (FCC-ee) system. The electron beam from a low-emittance RF gun is accelerated by an S-band linac up to 6 GeV. A damping ring at 1.54 GeV is required for emittance cooling of the positron beam. The intermediate energy step from the exit of the S-band linac at 6 GeV to the 20 GeV injection energy of the top-up booster can be provided by the modified Super Proton Synchrotron (SPS), serving as a pre-booster ring (PBR). An alternative option to reach 20 GeV energy would be to extend the S-band linac with a C- or X-band linac. An overall cost optimisation will determine the choice of the final configuration. Beam loss and emittance dilution in the linac due to space charge effects, wakefields, and misalignment of accelerator components can be mitigated by RF phasing and orbit steering. Start-to-end simulations examine the beam transport through the linac up to either 6 GeV or 20 GeV. The results indicate large design margins. Simulations of the beam dynamics in the damping ring (DR) demonstrate a sufficiently large momentum acceptance. Effects of intrabeam scattering and electron cloud instability in the DR are also studied. PB - JACoW Publishing CP - Geneva, Switzerland SP - 420 EP - 423 KW - linac KW - emittance KW - positron KW - gun KW - electron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP002 UR - http://jacow.org/ipac2019/papers/mopmp002.pdf ER - TY - CONF AU - Chaikovska, I. AU - Apyan, A. AU - Chehab, R. AU - Enomoto, Y. AU - Faus-Golfe, A. AU - Furukawa, K. AU - Han, Y. AU - Kamitani, T. AU - Martyshkin, P.V. AU - Miyahara, F. AU - Ogur, S. AU - Oide, K. AU - Papaphilippou, Y. AU - Rinolfi, L. AU - Satoh, M. AU - Seimiya, Y. AU - Sievers, P. AU - Suwada, T. AU - Zimmermann, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Positron Source for FCC-ee J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The FCC-ee is a high-luminosity, high-precision circular collider to be constructed in a new 100 km tunnel in the Geneva area. The physics case is well established and the FCC-ee operation is foreseen at 91 GeV (Z-pole), 160 GeV (W pair production threshold), 240 GeV (Higgs resonance) and 365 GeV (t-tbar threshold). Due to the large 6D production emittance and important thermal load in the production target, the positron injector, in particular the positron source, is one of the key elements of the FCC-ee, requiring special attention. To ensure high reliability of the positron source, conventional and hybrid targets are currently under study. The final choice of the positron target will be made based on the estimated performances. In this framework, we present a preliminary design of the FCC-ee positron source, with detailed simulation studies of positron production, capture and primary acceleration. PB - JACoW Publishing CP - Geneva, Switzerland SP - 424 EP - 427 KW - positron KW - target KW - linac KW - electron KW - collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP003 UR - http://jacow.org/ipac2019/papers/mopmp003.pdf ER - TY - CONF AU - Chancé, A. AU - Bartmann, W. AU - Boutin, D. AU - Dalena, B. AU - Hofer, M. AU - Martin, R. AU - Schulte, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Consolidated Lattice of the Collider FCC-hh J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. The latest changes brought to the lattice of the FCC-hh collider are commented: impact of the new intra-beam distance, efforts to increase the beam stay clear in the dispersion suppressors, tuning procedures, and updates on the insertions. PB - JACoW Publishing CP - Geneva, Switzerland SP - 428 EP - 431 KW - dipole KW - quadrupole KW - injection KW - optics KW - insertion DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP004 UR - http://jacow.org/ipac2019/papers/mopmp004.pdf ER - TY - CONF AU - Dalena, B. AU - Boutin, D. AU - Chancé, A. AU - Cruz Alaniz, E. AU - Schulte, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Field Quality for the Hadron Option of Future Circular Collider J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The updated field quality for the baseline design option of the Nb₃Sn dipoles for Future Circular Collider (FCC-hh) is discussed. The impact on the expected dynamic aperture is shown at injection and collision energy and the consequent non-linear correction schemes together with their integration in the optics are defined. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4397 EP - 4400 KW - injection KW - dipole KW - octupole KW - collider KW - target DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP005 UR - http://jacow.org/ipac2019/papers/mopmp005.pdf ER - TY - CONF AU - Blaskovic Kraljevic, N. AU - Arominski, D. AU - Schulte, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Intra-Bunch Energy Spread Minimisation for CLIC Operation at a Centre-of-Mass Energy of 350 GeV J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The first stage of the electron-positron Compact Linear Collider (CLIC) is designed with a centre-of-mass energy of 380 GeV. A dedicated threshold scan in the vicinity of 350 GeV is envisioned with a total integrated luminosity of 100 fb⁻¹. This scan calls for a very small intra-bunch energy spread in order to achieve an excellent collision energy resolution. This paper presents an optimised assignment of RF accelerating gradients and phases in the CLIC main linac for operation at 350 GeV, which minimises the energy spread at the end of the main linac whilst preserving a small emittance growth. Variation of the bunch length and charge is studied in order to further reduce the energy spread; the effect on both the peak and total luminosity is discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 458 EP - 460 KW - linac KW - luminosity KW - collider KW - emittance KW - linear-collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP016 UR - http://jacow.org/ipac2019/papers/mopmp016.pdf ER - TY - CONF AU - Blaskovic Kraljevic, N. AU - Schulte, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Beam Orbit Correction in the CLIC Main Linac Using a Small Subset of Correctors J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Beam orbit correction in future linear colliders, such as the Compact Linear Collider (CLIC), is essential to mitigate the effect of accelerator element misalignment due to ground motion. The correction is performed using correctors distributed along the accelerator, based on the beam position monitor (BPM) readout from the preceding bunch train, with a train repetition frequency of 50 Hz. This paper presents the use of the MICADO algorithm* to select a subset of N ~ 10 correctors (from a total of 576) to be used for orbit correction in the designed 380 GeV centre-of-mass energy first-stage of CLIC. The optimisation of the number N of correctors, the algorithm’s gain and the corrector step size is described, and the impact of a number of BPMs and correctors becoming unavailable is addressed. The application of a MICADO algorithm to perform dispersion free steering, by reducing the beam orbit difference between two beams with different energies, is discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 461 EP - 464 KW - linac KW - emittance KW - quadrupole KW - collider KW - ground-motion DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP017 UR - http://jacow.org/ipac2019/papers/mopmp017.pdf ER - TY - CONF AU - Blaskovic Kraljevic, N. AU - Schulte, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Beam-Based Beamline Element Alignment for the Main Linac of the 380 GeV Stage of CLIC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The extremely small vertical beam size required at the interaction point of future linear colliders, such as the Compact Linear Collider (CLIC), calls for a very small vertical emittance. The strong wakefields in the high frequency 12 GHz CLIC accelerating structures set tight tolerances on the alignment of the main linac’s beamline elements and on the correction of the beam orbit through them in order to mantain a small emittance growth. This paper presents the emittance growth due to each type of beamline element misalignment in the designed 380 GeV centre-of-mass energy first-stage of CLIC, and the emittance growth following a series of beam-based alignment (BBA) procedures. The BBA techniques used are one-to-one steering, followed by dispersion free steering and finally accelerating structure alignment using wakefield monitors. PB - JACoW Publishing CP - Geneva, Switzerland SP - 465 EP - 467 KW - emittance KW - linac KW - alignment KW - collider KW - wakefield DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP018 UR - http://jacow.org/ipac2019/papers/mopmp018.pdf ER - TY - CONF AU - De Maria, R. AU - Bruce, R. AU - Gamba, D. AU - Giovannozzi, M. AU - Plassard, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - High Luminosity LHC Optics and Layout HLLHCV1.4 J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The goal of the High Luminosity Project is the upgrade of the LHC to deliver an integrated luminosity of at least 250 \rm fb⁻¹ per year in each of the two high-luminosity, general-purpose detectors ATLAS and CMS. This article presents the latest layout design and the corresponding optics features, which comprise optimisation of the orbit corrector and crab cavity systems, and new estimates of the performance reach thanks to the new concept of fully remote alignment. In addition, the new optics version incorporates improvements required by beam instrumentation, dump system, and collimation system, as well as low-beta solutions for the LHCb experiment. PB - JACoW Publishing CP - Geneva, Switzerland SP - 468 EP - 471 KW - optics KW - luminosity KW - operation KW - experiment KW - cavity DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP019 UR - http://jacow.org/ipac2019/papers/mopmp019.pdf ER - TY - CONF AU - De Maria, R. AU - Solfaroli, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Smooth and Beta-Beating-Free Optics Transitions for HL-LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the CERN LHC, optics transitions are mainly required to control the beam size at the four experimental interaction points. The current method, based on linearly-interpolated optics functions over a small set of matched optics and parabolic time-domain segments, introduces non-zero beta-beating and it is not optimal in time. This contribution presents an alternative approach, based on continuously-matched optics solutions distributed in time domain by using a realistic model of the superconducting circuits, which optimises the overall process duration. This method requires a change in the paradigm used in the control system and it is proposed for the future High Luminosity LHC (HL-LHC) runs. PB - JACoW Publishing CP - Geneva, Switzerland SP - 472 EP - 475 KW - optics KW - injection KW - quadrupole KW - insertion KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP020 UR - http://jacow.org/ipac2019/papers/mopmp020.pdf ER - TY - CONF AU - Hofer, M. AU - Carlier, F.S. AU - Tomás, R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - K-Modulation in Future High Energy Colliders J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - K-Modulation of the quadrupoles closest to the interaction point (IP) has been an indispensable tool to accurately measure the beta-function in the interaction point (β^{*}) in the Large Hadron Collider (LHC) at CERN. K-Modulation may become even more important to control the lower β^{*} and reach the design luminosities in the High-Luminosity LHC (HL-LHC) and the Future Circular Collider (FCC). K-Modulation results also provide important input for the luminosity calibration and help in the identification and correction of errors in the machines. This paper presents a method for determining β^{*} using K-Modulation adapted to the characteristic layout of both colliders. Using the latest models for the HL-LHC and the FCC-hh, estimated uncertainties on the measurements are presented. The results are compared to the accuracy of an alternative modulation scheme using a different powering scheme. PB - JACoW Publishing CP - Geneva, Switzerland SP - 476 EP - 479 KW - quadrupole KW - luminosity KW - collider KW - optics KW - power-supply DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP022 UR - http://jacow.org/ipac2019/papers/mopmp022.pdf ER - TY - CONF AU - Hofer, M. AU - Giovannozzi, M. AU - Keintzel, J. AU - Tomás, R. AU - Zimmermann, F. AU - van Riesen-Haupt, L. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Dynamic Aperture at Injection Energy for the HE-LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - As part of the Future Circular Collider study, the High Energy LHC (HE-LHC) is a proposed hadron collider situated in the already existing LHC tunnel. It aims at achieving a center of mass energy of 27 TeV, almost doubling the design c.o.m. energy of the LHC. This increase in energy relies on the use of 16 T Nb₃Sn dipoles to be developed for the FCC-hh. The field quality of these dipoles is expected to have a big impact on the Dynamic Aperture (DA) at injection energy and subsequently tracking studies are conducted to evaluate the impact of magnetic field errors on the beam dynamics. In the following the results of these studies for the different injection energies considered for the HE-LHC are presented and a possible strategy for increasing the DA are discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 480 EP - 483 KW - dipole KW - injection KW - lattice KW - dynamic-aperture KW - collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP023 UR - http://jacow.org/ipac2019/papers/mopmp023.pdf ER - TY - CONF AU - Jebramcik, M.A. AU - Jowett, J.M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Prospects for Future Asymmetric Collisions in the LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The proton-lead runs of the LHC in 2012, 2013 and 2016 provided luminosity far beyond expectations in a diversity of operating conditions and led to important new results in high-density QCD. This has permitted the scope of the future physics programme to be expanded in a recent review. Besides further high-luminosity p-Pb collisions, lighter nuclei are also under consideration. A short proton-oxygen run, on the model of the 2012 p-Pb run, would be of interest for cosmic-ray physics. Other collision systems like proton-argon or collisions of protons with other noble gases are also discussed. We provide an overview of the operational strategies and potential performance of various asymmetric collision options. Potential performance limits from moving beam-beam encounters at injection and various beam-loss mechanisms are evaluated in the light of our understanding of the LHC to date. PB - JACoW Publishing CP - Geneva, Switzerland SP - 484 EP - 487 KW - proton KW - luminosity KW - experiment KW - operation KW - hadron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP024 UR - http://jacow.org/ipac2019/papers/mopmp024.pdf ER - TY - CONF AU - Jebramcik, M.A. AU - Jowett, J.M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Moving Long-range Beam-beam Encounters in Heavy-ion Colliders J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Asymmetric ion beam collisions like proton-lead in the LHC or gold-deuteron in RHIC have become major components of heavy-ion physics programmes. The injection and ramp of two different ion species with the same magnetic rigidity and consequently unequal revolution frequencies generate moving long-range beam-beam encounters in the interactions regions of the collider. These encounters led to fast beam losses and can cause emittance blow-up as observed in RHIC in the early 2000s and, more recently, in 2015. Yet such effects are absent at the LHC so the difference between the two colliders requires explanation. Tools and models have been developed to describe the beam dynamics of moving long-range beam-beam encounters and to predict the evolution of emittance and other beam parameters. Besides presenting results for RHIC and the LHC we give an outlook for the HL-LHC and potential operational restrictions. PB - JACoW Publishing CP - Geneva, Switzerland SP - 488 EP - 491 KW - proton KW - emittance KW - injection KW - collider KW - acceleration DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP025 UR - http://jacow.org/ipac2019/papers/mopmp025.pdf ER - TY - CONF AU - Keintzel, J. AU - Crouch, M.P. AU - Hofer, M. AU - Risselada, T. AU - Tomás, R. AU - Zimmermann, F. AU - van Riesen-Haupt, L. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - HE-LHC Optics Design Options J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The High Energy Large Hadron Collider (HE-LHC), a possible successor of the High Luminosity Large Hadron Collider (HL-LHC) aims at reaching a centre-of-mass energy of about 27 TeV using basically the same 16 T dipoles as for the hadron-hadron Future Circular Collider FCC-hh. Designing the HE-LHC results in a trade off between energy reach, beam stay clear as well as geometry offset with respect to the LHC. In order to best meet the requirements, various arc cell and dispersion suppressor options have been generated and analysed, before concluding on two baseline options, which are presented in this paper. Merits of each design are highlighted and possible solutions for beam stay clear minima are presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 492 EP - 495 KW - dipole KW - lattice KW - quadrupole KW - hadron KW - optics DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP026 UR - http://jacow.org/ipac2019/papers/mopmp026.pdf ER - TY - CONF AU - Keintzel, J. AU - Coello de Portugal, J.M. AU - Dilly, J. AU - Fol, E. AU - Garcia-Tabares, A. AU - Hofer, M. AU - Maclean, E.H. AU - Malina, L. AU - Persson, T.H.B. AU - Tomás, R. AU - Wegscheider, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Second Order Dispersion Measurements in LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The quadratic dependence of the orbit on the relative momentum offset, also known as second order dispersion, is analysed for the first time for the LHC. In this paper, the measurement and analysis procedure are described. Results and implications on future optics are discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 496 EP - 499 KW - optics KW - dipole KW - coupling KW - quadrupole KW - betatron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP027 UR - http://jacow.org/ipac2019/papers/mopmp027.pdf ER - TY - CONF AU - Paraschou, K. AU - Iadarola, G. AU - Karastathis, N. AU - Kostoglou, S. AU - Papaphilippou, Y. AU - Sabato, L. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Analysis on Bunch-by-Bunch Beam Losses at 6.5 TeV in the Large Hadron Collider J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In 2018, a large fraction of the physics data taking at the Large Hadron Collider has been performed with a beam energy of 6.5 TeV, the nominal bunch spacing of 25 ns and beta functions at the high luminosity interaction points of 30 cm. In order to maximize the integrated luminosity, the crossing angles are gradually reduced as the beam intensity reduces due to luminosity burn-off. In these conditions the beam lifetime is visibly affected by collective effects and in particular by beam-beam interaction and electron cloud effects. By analyzing the beam losses at a bunch-by-bunch level, it is possible to disentangle the contributions from different effects and to assess the impact on the losses of changes applied to the machine configuration. PB - JACoW Publishing CP - Geneva, Switzerland SP - 500 EP - 503 KW - luminosity KW - betatron KW - beam-losses KW - operation KW - collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP029 UR - http://jacow.org/ipac2019/papers/mopmp029.pdf ER - TY - CONF AU - Steerenberg, R. AU - Albert, M. AU - Alemany-Fernández, R. AU - Argyropoulos, T. AU - Bravin, E. AU - Crockford, G.E. AU - Dumont, J.-C. AU - Fuchsberger, K. AU - Giachino, R. AU - Giovannozzi, M. AU - Hemelsoet, G.H. AU - Höfle, W. AU - Jacquet, D. AU - Lamont, M. AU - Métral, E. AU - Nisbet, D. AU - Papotti, G. AU - Pojer, M. AU - Ponce, L. AU - Redaelli, S. AU - Salvachua, B. AU - Schaumann, M. AU - Solfaroli, M. AU - Suykerbuyk, R. AU - Trad, G. AU - Uythoven, J.A. AU - Uznanski, S. AU - Walsh, D.J. AU - Wenninger, J. AU - Zerlauth, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Operation and Performance of the Cern Large Hadron Collider During Proton Run 2 J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Run 2 of the CERN Large Hadron Collider (LHC) was successfully completed on 10th December 2018, achieving largely all goals set in terms of luminosity production. Following the first two-year long shutdown and the re-commissioning in 2015 at 6.5 TeV, the beam performance was increased to reach a peak luminosity of more than twice the design value and a colliding beam time ratio of 50%. This was accomplished thanks to the increased beam brightness from the injector chain, the high machine availability and the performance enhancements made in the LHC for which some methods and tools, foreseen for the High Luminosity LHC (HL-LHC) were tested and deployed operationally. This contribution provides an overview of the operational aspects, main limitations and achievements for the proton Run 2. PB - JACoW Publishing CP - Geneva, Switzerland SP - 504 EP - 507 KW - luminosity KW - operation KW - proton KW - emittance KW - injection DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP031 UR - http://jacow.org/ipac2019/papers/mopmp031.pdf ER - TY - CONF AU - Tomás, R. AU - Carlier, F.S. AU - Coello de Portugal, J.M. AU - Dilly, J. AU - Fartoukh, S.D. AU - Fol, E. AU - Gamba, D. AU - Garcia-Tabares, A. AU - Giovannozzi, M. AU - Hofer, M. AU - Maclean, E.H. AU - Malina, L. AU - Persson, T.H.B. AU - Skowroński, P.K. AU - Solfaroli, M. AU - Spitznagel, M.L. AU - Wegscheider, A. AU - Wenninger, J. AU - Wolf, D.W. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - LHC Run 2 Optics Commissioning Experience in View of HL-LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - LHC Run 2 has achieved a beta lower than a factor 2 below design. This has significantly challenged optics measurement and correction techniques in the linear and non-linear regimes, leading to the development of new approaches. Furthermore, experimenting with a large variety of optics has allowed facing the difficulties of future optics and gaining understanding of the machine imperfections. A summary of these aspects is given in view of their implications for the HL-LHC Project. PB - JACoW Publishing CP - Geneva, Switzerland SP - 508 EP - 511 KW - optics KW - luminosity KW - coupling KW - simulation KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP033 UR - http://jacow.org/ipac2019/papers/mopmp033.pdf ER - TY - CONF AU - Ögren, J. AU - Latina, A. AU - Schulte, D. AU - Tomás, R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Tuning Studies of the CLIC 380 Gev Final Focus System J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We present tuning studies of the Compact Linear Collider final-focus system under static imperfections including transverse misalignments, roll errors and magnetic strength errors. The tuning procedure consists of beam-based alignment for correcting the linear part of the system followed by sextupole pre-alignment and use of multipole tuning knobs. The sextupole pre-alignment is very robust and allows the tuning time to be greatly reduced. PB - JACoW Publishing CP - Geneva, Switzerland SP - 512 EP - 515 KW - sextupole KW - luminosity KW - alignment KW - collider KW - linear-collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP034 UR - http://jacow.org/ipac2019/papers/mopmp034.pdf ER - TY - CONF AU - Valdivia García, M.A. AU - Zimmermann, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Effect of Emittance Constraints on Monochromatization at the Future  Circular e⁺e⁻ Collider J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Direct s-channel Higgs production in e+e− collisions is of interest if the collision energy spread can be comparable to the natural width of the standard model Higgs boson. At the Future Circular e⁺e⁻ Collider (FCC-ee), a monochromatization scheme could be employed in order to reduce the collision energy spread to the target value. This may be achieved by introducing a non-zero horizontal dispersion of opposite sign for the two colliding beams at the interaction point. In this case, the beamstrahlung increases the horizontal emittance in addition to energy spread and bunch length.  The vertical emittance could either be tuned to a certain minimum value, possibly limited by the diagnostics resolution, or it could scale linearly with the horizontal emittance. For the FCC-ee at 62.5 GeV beam energy, we optimize the IP optics and beam parameters, considering these two different assumptions for the vertical emittance. We derive the maximum achievable luminosity as a function of collision energy spread for either case. PB - JACoW Publishing CP - Geneva, Switzerland SP - 516 EP - 519 KW - emittance KW - luminosity KW - collider KW - radiation KW - photon DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP035 UR - http://jacow.org/ipac2019/papers/mopmp035.pdf ER - TY - CONF AU - Lindstrom, B. AU - Bartosik, H. AU - Bohl, T. AU - Butterworth, A.C. AU - Calaga, R. AU - Carver, L.R. AU - Kain, V. AU - Levens, T.E. AU - Papotti, G. AU - Secondo, R. AU - Uythoven, J.A. AU - Valette, M. AU - Vandoni, G. AU - Wenninger, J. AU - Wollmann, D. AU - Zerlauth, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Machine Protection Experience from Beam Tests with Crab Cavity Prototypes in the CERN SPS J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Crab cavities (CCs) constitute a key component of the High Luminosity LHC (HL-LHC) project. In case of a failure, they can induce significant transverse beam offsets within tens of microseconds, necessitating a fast removal of the circulating beam to avoid damage to accelerator components due to losses from the displaced beam halo. In preparation for the final design to be employed in the LHC, a series of tests were conducted on prototype crab cavities installed in the Super Proton Synchrotron (SPS) at CERN. This paper summarizes the machine protection requirements and observations during the first tests of crab cavities with proton beams in the SPS. In addition, the machine protection implications for future SPS tests and for the use of such equipment in the HL-LHC are discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 520 EP - 523 KW - cavity KW - machine-protect KW - beam-losses KW - betatron KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP036 UR - http://jacow.org/ipac2019/papers/mopmp036.pdf ER - TY - CONF AU - Zimmermann, F. AU - Abelleira, J.L. AU - Abramov, A. AU - Amorim, D. AU - Antipov, S.A. AU - Apyan, A. AU - Arsenyev, S. AU - Barranco García, J. AU - Benedikt, M. AU - Bruce, R. AU - Burkart, F. AU - Cai, Y. AU - Crouch, M.P. AU - Cruz Alaniz, E. AU - Fartoukh, S.D. AU - Giovannozzi, M. AU - Goddard, B. AU - Guillermo Cantón, G. AU - Hofer, M. AU - Keintzel, J. AU - Kersevan, R. AU - Mertens, V. AU - Mether, L. AU - Molson, J. AU - Muttoni, Y. AU - Nosochkov, Y.M. AU - Ohmi, K. AU - Oide, K. AU - Osborne, J.A. AU - Parma, V. AU - Pieloni, T. AU - Pikhartova, H. AU - Raginel, V. AU - Redaelli, S. AU - Risselada, T. AU - Rivkin, L. AU - Ruehl, I. AU - Salvant, B. AU - Schoerling, D. AU - Seryi, A. AU - Shaposhnikova, E.N. AU - Tambasco, C. AU - Tavian, L.J. AU - Todesco, E. AU - Tommasini, D. AU - Tomás, R. AU - Valchkova-Georgieva, F. AU - Venturi, V. AU - Wollmann, D. AU - Zhou, D. AU - van Riesen-Haupt, L. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Updated High-Energy LHC Design J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We present updated design parameters for a future High-Energy LHC. A more realistic turnaround time has led to a revision of the target peak luminosity, as well as a choice of a larger IP beta function, and longer physics fills. Pushed parameters of the Nb₃Sn superconducting cable together with a modified layout of the 16 T dipole magnets resulted in revised field errors, updated dynamic-aperture simulations, and an associated re-evaluation of injector options. Collimators in the dispersion suppressors help achieve satisfactory cleaning performance. Longitudinal beam parameters ensure beam stability throughout the cycle. Intrabeam scattering rates and Touschek lifetime appear benign. PB - JACoW Publishing CP - Geneva, Switzerland SP - 524 EP - 527 KW - injection KW - emittance KW - proton KW - impedance KW - damping DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP037 UR - http://jacow.org/ipac2019/papers/mopmp037.pdf ER - TY - CONF AU - Bodenstein, R.M. AU - Abramov, A. AU - Boogert, S.T. AU - Burrows, P. AU - Nevay, L.J. AU - Schulte, D. AU - Tomás, R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Investigation of CLIC 380 GeV Post-Collision Line J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - It has been proposed that the Compact Linear Collider (CLIC) be commissioned in stages, starting with a lower-energy, 380 GeV version for the first stage, and concluding with a 3 TeV version for the final stage. In the Conceptual Design Report (CDR) published in 2012, the post-collision line is described for the 3 TeV and 500 GeV stages. However, the post-collision line for the 380 GeV design was not investigated. This work will describe the simulation studies performed in BDSIM for the 380 GeV post-collision line. PB - JACoW Publishing CP - Geneva, Switzerland SP - 528 EP - 531 KW - simulation KW - site KW - dipole KW - collider KW - linear-collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP038 UR - http://jacow.org/ipac2019/papers/mopmp038.pdf ER - TY - CONF AU - van Riesen-Haupt, L. AU - Abelleira, J.L. AU - Barranco García, J. AU - Cruz Alaniz, E. AU - Hofer, M. AU - Keintzel, J. AU - Pieloni, T. AU - Tambasco, C. AU - Tomás, R. AU - Zimmermann, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Developments in the Experimental Interaction Regions of the High Energy LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The High Energy LHC (HE-LHC) aims to collide 13.5 TeV protons in two high luminosity experiments and two low luminosity experiments. In the following, the recent updates in the two high luminosity experimental interaction regions (EIR) of the HE-LHC will be illustrated. These EIR aim to focus the beams to a β^{*} of 0.45 m at the interaction point (IP) to achieve a lifetime integrated luminosity of 10 ab⁻¹. On top of the triplet optics designed to achieve this, it will present energy deposition driven separation dipole designs, optics solutions for the matching section and dispersion suppressors as well as studies involving the integration into the lattice options. In particular it will outline geometric considerations, spurious dispersion suppression as well as results from dynamic aperture studies. PB - JACoW Publishing CP - Geneva, Switzerland SP - 532 EP - 535 KW - dipole KW - luminosity KW - dynamic-aperture KW - beam-beam-effects KW - shielding DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP039 UR - http://jacow.org/ipac2019/papers/mopmp039.pdf ER - TY - CONF AU - Poyet, A. AU - Fartoukh, S.D. AU - Karastathis, N. AU - Papaphilippou, Y. AU - Skoufaris, K. AU - Sterbini, G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Numerical Simulations of the DC Wire Prototypes in LHC for Enhancing the HL-LHC Performances J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - For the last 15 years, the compensation of the Beam-Beam Long-Range (BBLR) interaction in colliders using DC wires has been studied. In 2015, in the frame of the HL-LHC project, it has been shown that a compensation of all the Resonance Driving Terms (RDTs) generated by the BBLR interaction is possible using wires with constraints on their transverse and longitudinal positions. In 2017, an experimental campaign has been launched in the present LHC, with wires installed in sub-optimal positions due to integration constraints. The aim of this paper is therefore to apply the formalism developped for HL-LHC to the LHC case and to compare the experimental results to the numerical tracking studies of the compensation using wires. PB - JACoW Publishing CP - Geneva, Switzerland SP - 566 EP - 569 KW - experiment KW - simulation KW - luminosity KW - optics KW - resonance DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP052 UR - http://jacow.org/ipac2019/papers/mopmp052.pdf ER - TY - CONF AU - Skoufaris, K. AU - Fartoukh, S.D. AU - Karastathis, N. AU - Papaphilippou, Y. AU - Pellegrini, D. AU - Poyet, A. AU - Rossi, A. AU - Sterbini, G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Numerical Optimization of DC Wire Compensation in HL-LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The electromagnetic field generated from a set of DC wires parallel to the beam opens the path to the compensation of the beam-beam long-range (BBLR) interactions for the future operation of large hadron colliders, in particular for the upcoming High Luminosity upgrade of the Large Hadron Collider (HL-LHC). The effectiveness and simplicity of a current carrying wire are critical for overcoming some technical constraints of the machine. In order to better understand the potential of this device for the HL-LHC, various simulation studies are presented. The different observables are the dynamic aperture and the frequency analysis. PB - JACoW Publishing CP - Geneva, Switzerland SP - 570 EP - 573 KW - operation KW - collider KW - luminosity KW - hadron KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPMP053 UR - http://jacow.org/ipac2019/papers/mopmp053.pdf ER - TY - CONF AU - Charles, T.K. AU - Aumon, S. AU - Holzer, B.J. AU - Oide, K. AU - Zimmermann, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Low Emittance Tuning of FCC-ee J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The FCC-ee project studies the design of a future 100 km e⁺/e⁻ circular collider for precision studies and rare decay observations in the range of 90 to 350 GeV center of mass energy with luminosities in the order of 10³⁶ cm⁻²s⁻¹. In order to reach these luminosity requirements, extreme focusing is needed in the interaction regions. For the Z energy (45.6 GeV) lattice, the maximum beta value is 8322 m, and the vertical beta function is 0.8 mm at the IP. These aspects of the FCC-ee lattice make it particularly susceptible to misalignments and field errors, and therefore present an appreciable challenge for emittance tuning. A challenging correction scheme is proposed to reduce the coupling and the vertical emittance. We describe a comprehensive correction strategy used for the low emittance tuning. The strategy includes special programs, that had been developed to optimise the lattice based on Dispersion Free Steering, linear coupling compensation based on Resonant Driving Terms and beta beat correction utilising response matrices. Thousands of misalignment and field error random seeds were introduced in MADX simulations and the final corrected lattices are presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 574 EP - 577 KW - emittance KW - coupling KW - lattice KW - quadrupole KW - sextupole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPRB001 UR - http://jacow.org/ipac2019/papers/moprb001.pdf ER - TY - CONF AU - Gorgi Zadeh, S. AU - Calaga, R. AU - Flisgen, T. AU - van Rienen, U. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - HOM Damping Options for the Z-Pole Operating Scenario of FCC-ee J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Z-pole option of FCC-ee is an Ampere class machine with a beam current of 1.39 A. Due to high HOM power and strong HOM damping requirements, the present baseline of FCC-ee considers a single cell cavity at 400 MHz. In this paper, different HOM damping schemes are compared for the Z-pole operating scenario with the aim of lowering the parasitic longitudinal and transverse impedance. The HOM power for each damping scheme is also calculated. PB - JACoW Publishing CP - Geneva, Switzerland SP - 590 EP - 593 KW - HOM KW - cavity KW - damping KW - impedance KW - dipole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPRB006 UR - http://jacow.org/ipac2019/papers/moprb006.pdf ER - TY - CONF AU - Zou, Y. AU - Bouquerel, E. AU - Dracos, M. AU - Ekelöf, T.J.C. AU - Eshraqi, M. AU - Gålnander, B. AU - Olvegård, M. AU - Ruber, R.J.M.Y. AU - Schönauer, H.O. AU - Wildner, E.H.M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Status of the ESSnuSB Accumulator Design J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The 2.0 GeV, 5 MW proton linac for the European Spallation Source, ESS, will have the capacity to accelerate additional pulses and send them to a neutrino target, providing an excellent opportunity to produce an unprecedented high performance neutrino beam, the ESS neutrino Super Beam, ESSnuSB, to measure, with precision, the CP violating phase at the 2nd oscillation maximum. In order to comply with the acceptance of the target and horn systems that will form the neutrino super beam, the long pulses from the linac must be compressed by about three orders of magnitude with minimal particle loss, something that will be achieved through multi-turn charge-exchange injection in an accumulator ring. This ring will accommodate over 2·10¹⁴ protons, which means that several design challenges are encountered. Strong space charge forces, low-loss injection with phase space painting, efficient collimation, a reliable charge stripping system, and e-p instabilities are some of the important aspects central to the design work. This paper presents the status of the accumulator ring design, with multi-particle simulations of the injections procedure. PB - JACoW Publishing CP - Geneva, Switzerland SP - 666 EP - 668 KW - linac KW - space-charge KW - injection KW - simulation KW - target DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPRB046 UR - http://jacow.org/ipac2019/papers/moprb046.pdf ER - TY - CONF AU - Bruce, R. AU - Abramov, A. AU - Bertarelli, A. AU - Besana, M.I. AU - Carra, F. AU - Cerutti, F. AU - Faus-Golfe, A. AU - Fiascaris, M. AU - Gobbi, G. AU - Krainer, A.M. AU - Lechner, A. AU - Mereghetti, A. AU - Mirarchi, D. AU - Molson, J. AU - Pasquali, M. AU - Redaelli, S. AU - Schulte, D. AU - Serluca, M. AU - Skordis, E. AU - Varasteh Anvar, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Collimation System Studies for the FCC-hh J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Future Circular Collider (FCC-hh) is being designed as a 100 km ring that should collide 50 TeV proton beams. At 8.3 GJ, its stored beam energy will be a factor 28 higher than what has been achieved in the Large Hadron Collider, which has the highest stored beam energy among the colliders built so far. This puts unprecedented demands on the control of beam losses and collimation, since even a tiny beam loss risks quenching superconducting magnets. We present in this article the design of the FCC-hh collimation system and study the beam cleaning through simulations of tracking, energy deposition, and thermo-mechanical response. We investigate the collimation performance for design beam loss scenarios and potential bottlenecks are highlighted. PB - JACoW Publishing CP - Geneva, Switzerland SP - 669 EP - 672 KW - collimation KW - proton KW - collider KW - simulation KW - hadron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPRB048 UR - http://jacow.org/ipac2019/papers/moprb048.pdf ER - TY - CONF AU - Boscolo Meneguolo, C. AU - Abramov, A. AU - Bruce, R. AU - Cerutti, F. AU - Ferro-Luzzi, M. AU - Giovannozzi, M. AU - Mereghetti, A. AU - Molson, J. AU - Redaelli, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Study of Beam-Gas Interactions at the LHC for the Physics Beyond Colliders Fixed-Target Study J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Among several working groups formed in the framework of Physics Beyond Colliders study, launched at CERN in September 2016, there is one investigating specific fixed-target experiment proposals. Of particular interest is the study of high-density unpolarized or polarized gas target to be installed in the LHCb detector, using storage cells to enhance the target density. This work studies the impact of the interactions of 7 TeV proton beams with such gas targets on the LHC machine in terms of particle losses. PB - JACoW Publishing CP - Geneva, Switzerland SP - 673 EP - 676 KW - target KW - proton KW - collider KW - experiment KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPRB049 UR - http://jacow.org/ipac2019/papers/moprb049.pdf ER - TY - CONF AU - Fuster-Martínez, N. AU - Bruce, R. AU - Jowett, J.M. AU - Mereghetti, A. AU - Mirarchi, D. AU - Redaelli, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Performance of the Collimation System During the 2018 Lead Ion Run at the Large Hadron Collider J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - As part of the Large Hadron Collider (LHC) heavy-ion research programme, the last month of the 2018 LHC run was dedicated to Pb ion physics. Several heavy-ion runs have been performed since the start-up of the LHC. These runs are challenging for collimation, despite lower intensities, because of the degraded cleaning observed compared to protons. This is due to the differences of the interaction mechanisms in the collimators. Ions experience fragmentation and electromagnetic dissociation that result in a substantial flux of off-rigidity particles that escape the collimation system. In this paper, the collimation system performance and the experience gained during the 2018 Pb ion run are presented. The measured performance is compared with the expectation from the Sixtrack-FLUKA coupling simulations and the agreement discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 677 EP - 680 KW - collimation KW - simulation KW - heavy-ion KW - proton KW - hadron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPRB050 UR - http://jacow.org/ipac2019/papers/moprb050.pdf ER - TY - CONF AU - Mereghetti, A. AU - Bruce, R. AU - Fuster-Martínez, N. AU - Mirarchi, D. AU - Redaelli, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Collimation System Upgrades for the High Luminosity Large Hadron Collider and Expected Cleaning Performance in Run 3 J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the framework of the High-Luminosity Large Hadron Collider project (HL-LHC), the LHC collimation system needs important upgrades to cope with the foreseen brighter beams. New collimation hardware will be installed in two phases, the first one during the LHC second Long Shutdown (LS2), in 2019-20, followed by a second phase starting in 2024 (LS3). This paper reviews the collimation upgrade plans for LS2, focused on a first impedance reduction of the system, through the installation of collimators based on new materials, and the improvement of collimation cleaning, achieved by adding new collimators in the cold dispersion suppressor regions. The performance of the new system in terms of cleaning inefficiency for proton and lead ion beams is presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 681 EP - 684 KW - collimation KW - proton KW - hadron KW - collider KW - dipole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPRB051 UR - http://jacow.org/ipac2019/papers/moprb051.pdf ER - TY - CONF AU - Dutheil, Y. AU - Alden, S.E. AU - Alemany-Fernández, R. AU - Apyan, A. AU - Bartosik, H. AU - Bessonov, E.G. AU - Biancacci, N. AU - Bosco, A. AU - Bruce, R. AU - Castelli, F. AU - Curatolo, C. AU - Czodrowski, P. AU - Fedosseev, V. AU - Gibson, S.M. AU - Goddard, B. AU - Hirlaender, S. AU - Jowett, J.M. AU - Kersevan, R. AU - Kowalska, M. AU - Kroeger, K. AU - Lamont, M. AU - Manglunki, D. AU - Martens, A. AU - Molson, J. AU - Nevay, L.J. AU - Petrenko, A.V. AU - Petrillo, V. AU - Sapinski, M. AU - Schaumann, M. AU - Serafini, L. AU - Stöhlker, T. AU - Weber, G. AU - Wu, Y.K. AU - Zimmermann, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Gamma Factory at CERN: Design of a Proof-of-Principle Experiment J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Gamma Factory (GF) initiative proposes to create novel research tools at CERN by producing, accelerating and storing highly relativistic partially stripped ion beams in the LHC rings and by exciting their atomic degrees of freedom by lasers, to produce high-energy photon beams. Their intensity would be several orders of magnitude higher than those of the presently operating light sources in the particularly interesting gamma-ray energy domain reaching up to 400 MeV. In this energy domain, the high-intensity photon beams can be used to produce secondary beams of polarized electrons, polarized positrons, polarized muons, neutrinos, neutrons and radioactive ions. Over the years 2017-2018 we have demonstrated that these partially stripped ion beams can be successfully produced, accelerated and stored in the CERN accelerator complex, including the LHC. The next step of the project is to build a proof of principle experiment in the SPS to validate the principal GF concepts. This contribution will present the initial conceptual design of this experiment along with its main challenge - the demonstration of the fast cooling method of partially stripped ion beams. PB - JACoW Publishing CP - Geneva, Switzerland SP - 685 EP - 688 KW - photon KW - laser KW - experiment KW - electron KW - cavity DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPRB052 UR - http://jacow.org/ipac2019/papers/moprb052.pdf ER - TY - CONF AU - Schaumann, M. AU - Alemany-Fernández, R. AU - Bartosik, H. AU - Bohl, T. AU - Bruce, R. AU - Hemelsoet, G.H. AU - Hirlaender, S. AU - Jowett, J.M. AU - Kain, V. AU - Krasny, M.W. AU - Molson, J. AU - Papotti, G. AU - Solfaroli Camillocci, M. AU - Timko, H. AU - Wenninger, J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - First Partially Stripped Ions in the LHC (208Pb⁸¹⁺) J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Gamma Factory initiative proposes to use partially stripped ion (PSI) beams as drivers of a new type of high intensity photon source. As part of the ongoing Physics Beyond Collider studies, initial beam tests with PSI beams have been executed at CERN. On 25 July 2018 lead ions with one remaining electron (208Pb⁸¹⁺) were injected and accelerated in the LHC for the first time. After establishing the injection and circulation of a few 208Pb⁸¹⁺ bunches, beam lifetimes of about 50 hours could be established at 6.5 TeV proton equivalent energy. This paper describes the setup of the beam tests and observations made. PB - JACoW Publishing CP - Geneva, Switzerland SP - 689 EP - 692 KW - experiment KW - injection KW - collimation KW - factory KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPRB055 UR - http://jacow.org/ipac2019/papers/moprb055.pdf ER - TY - CONF AU - Abramov, A. AU - Bruce, R. AU - Fuster-Martínez, N. AU - Gorzawski, A.A. AU - Krasny, M.W. AU - Molson, J. AU - Nevay, L.J. AU - Redaelli, S. AU - Schaumann, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Collimation of Partially Stripped Ion Beams in the LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the scope of the Physics Beyond Colliders studies, the Gamma Factory initiative proposes the use of partially stripped ions as a driver of a new type, high intensity photon source in CERN’s Large Hadron Collider (LHC). In 2018, the LHC accelerated and stored partially stripped 208-Pb-81+ ions for the first time. The collimation system efficiency recorded during this test was found to be prohibitively low. The worst losses were localised in the dispersion suppressor (DS) of the betatron-cleaning insertion. Analytic arguments and simulations show that the large losses are driven by the stripping of the remaining electron from the Pb nucleus by the primary collimators. The rising dispersion in the DS pushes the resulting off-rigidity, fully-stripped ions into the aperture of the superconducting magnets. In this study the measured loss maps are compared against results from simulations. Different mitigation strategies are outlined, including a dispersion suppressor (DS) collimator, crystal collimation or an orbit bump. PB - JACoW Publishing CP - Geneva, Switzerland SP - 700 EP - 703 KW - collimation KW - simulation KW - operation KW - collider KW - hadron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPRB058 UR - http://jacow.org/ipac2019/papers/moprb058.pdf ER - TY - CONF AU - Abramov, A. AU - Bruce, R. AU - Crouch, M.P. AU - Fuster-Martínez, N. AU - Mereghetti, A. AU - Molson, J. AU - Nevay, L.J. AU - Redaelli, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Collimation of Heavy-Ion Beams in the HE-LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A design study for a future collider to be built in the LHC tunnel, the High-Energy Large Hadron Collider (HE-LHC), has been launched as part of the Future Circular Collider (FCC) study at CERN. It would provide proton collisions at a centre-of-mass energy of 27 TeV as well as collisions of heavy ions at the equivalent magnetic rigidity. HE-LHC is being designed under the stringent constraint of using the existing tunnel and therefore the resulting lattice and optics differ in layout and phase advance from the LHC. It is necessary to evaluate the performance of the collimation system for ion beams in HE-LHC in addition to proton beams. In the case of ion beams, the fragmentation and electromagnetic dissociation that relativistic heavy ions can undergo in collimators, as well as the unprecedented energy per nucleon of the HE-LHC, requires dedicated simulations. Results from a study of collimation efficiency for the nominal lead ion (Pb-82-208) beams performed with the SixTrack-FLUKA coupling framework are presented. These include loss maps with comparison against an estimated quench limit as well as detailed considerations of loss spikes in the superconducting aperture for critical sections of the machine such as the dispersion suppressors. PB - JACoW Publishing CP - Geneva, Switzerland SP - 704 EP - 707 KW - collimation KW - collider KW - proton KW - hadron KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPRB059 UR - http://jacow.org/ipac2019/papers/moprb059.pdf ER - TY - CONF AU - Vossberg, M. AU - Bencini, V. AU - Garland, J.M. AU - Gerhard, P. AU - Groening, L. AU - Lallement, J.-B. AU - Lombardi, A.M. AU - Mickat, S. AU - Vormann, H. AU - Xiao, C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - RFQ Electrodes Change and Upgrade Option at the UNILAC HSI Injector J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In order to meet the beam intensity and quality requirements imposed by FAIR, the HSI-RFQ beam dynamics originally dating from 2009 has been re-designed recently at CERN. Front-to-end simulations demonstrated that the new design meets the FAIR targets. Implementation of the new electrodes, initially planned for 2019, will require re-adaption of the RFQ cavity rf-parameters by re-shaping the stems that keep the electrodes. However, during the beam time 2018 the existing RFQ did not reach its nominal voltage most likely due to expired lifetime of the electrodes originating from 2009. In order to shorten the RFQ maintenance period and to minimize any risk for upcoming beam time 2019, it was decided to post-pone the implementation of the new design and rather just re-producing the 2009 design electrodes. This contribution is on the re-production process as short-term solution and on the full implementation of the new design as mid-term solution. CST simulations performed at GSI assure that the resonance frequency with the new electrode geometry is recuperated through corrections of the carrier rings. The status of the exchange of the electrodes and simulations for the adaptation of the new electrode design are presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 936 EP - 939 KW - rfq KW - simulation KW - operation KW - cavity KW - MMI DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS036 UR - http://jacow.org/ipac2019/papers/mopts036.pdf ER - TY - CONF AU - Sjobak, K.N. AU - Adli, E. AU - Bergamaschi, M. AU - Burger, S. AU - Corsini, R. AU - Curcio, A. AU - Curt, S. AU - Döbert, S. AU - Farabolini, W. AU - Gamba, D. AU - Garolfi, L. AU - Gilardi, A. AU - Gorgisyan, I. AU - Granados, E. AU - Guerin, H. AU - Kieffer, R. AU - Krupa, M. AU - Lefèvre, T. AU - Lindstrøm, C.A. AU - Lyapin, A. AU - Mazzoni, S. AU - McMonagle, G. AU - Nadenau, N. AU - Panuganti, H. AU - Pitman, S. AU - Rude, V. AU - Schlogelhofer, A. AU - Skowroński, P.K. AU - Wendt, M. AU - Zemanek, A.P. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Status of the CLEAR Electron Beam User Facility at CERN J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The CERN Linear Electron Accelerator for Research (CLEAR) has now finished its second year of operation, providing a testbed for new accelerator technologies and a versatile radiation source. Hosting a varied experimental program, this beamline provides a flexible test facility for users both internal and external to CERN, as well as being an excellent accelerator physics training ground. The energy can be varied between 60 and 220 MeV, bunch length between 1 and 4 ps, bunch charge in the range 10 pC to 2 nC, and number of bunches in the range 1 to 200, at a repetition rate of 0.8 to 10 Hz. The status of the facility with an overview of the recent experimental results is presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 983 EP - 986 KW - experiment KW - electron KW - radiation KW - plasma KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS054 UR - http://jacow.org/ipac2019/papers/mopts054.pdf ER - TY - CONF AU - Gålnander, B. AU - Collins, M. AU - Eshraqi, M. AU - Farricker, A. AU - Martins, C.A. AU - Miyamoto, R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Status of ESS Linac Upgrade Studies for ESSnuSB J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The European Spallation Source (ESS), currently under construction in Lund, Sweden, is the world’s most powerful neutron spallation source, with an average power of 5 MW at 2.0 GeV. In the ESS neutrino Super Beam Project (ESSnuSB) it is proposed to utilise this powerful accelerator as a proton driver for a neutrino beam that will be sent to a large underground Cherenkov detector in Garpenberg, mid-Sweden. In this paper we discuss the required modifications of the ESS linac to reach an additional 5 MW beam power for neutrino production in parallel to the spallation neutron production. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1038 EP - 1041 KW - linac KW - ion-source KW - proton KW - extraction KW - neutron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS082 UR - http://jacow.org/ipac2019/papers/mopts082.pdf ER - TY - CONF AU - Di Giovanni, G.P. AU - Antoniou, F. AU - Blas, A. AU - Brischetto, Y. AU - Findlay, A. AU - Kotzian, G. AU - Mikulec, B. AU - Sterbini, G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Commissioning of a New Digital Transverse Damper System at the PSB J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - At the CERN Proton Synchrotron Booster, PSB, an analog transverse damper system has been in operation since 1999, providing satisfactory operational results with the proton beam supplied by Linac2. As a consequence of the LHC Injectors Upgrade, the PSB will face new challenges imposed by higher intensity, injection and extraction energy. In this framework, the transverse feedback system is subject to an upgrade to adapt to the expected Linac4 beam and to the demands for new features including transverse blow-up, beam excitation for optics measurements and new remote control and monitoring capabilities. The replacement of the aging electronic hardware is also recommended to improve the system maintainability for future years. During 2018 a new digital transverse feedback electronics was installed in the PSB, in parallel with the current operational one, offering for the first time the occasion to demonstrate its performance with beam. Encouraging results were obtained such as the suppression of beam instabilities at all PSB energies and intensities. In this paper we describe the steps undertaken in 2018 in order to commission the system with the main goal to accelerate and extract the highest intensity beams produced at the PSB. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1050 EP - 1053 KW - feedback KW - proton KW - operation KW - MMI KW - hardware DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS085 UR - http://jacow.org/ipac2019/papers/mopts085.pdf ER - TY - CONF AU - Santamaría García, A. AU - Albright, S.C.P. AU - Antoniou, F. AU - Asvesta, F. AU - Bartosik, H. AU - Di Giovanni, G.P. AU - Mikulec, B. AU - Rafique, H. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Identification and Compensation of Betatronic Resonances in the Proton Synchrotron Booster at 160 Mev J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Proton Synchrotron Booster (PSB) is the first circular accelerator in the injector chain to the Large Hadron Collider (LHC) and accelerates protons from 50 MeV to 1.4 GeV. The PSB will need to deliver two times the current brightness after the LHC Injectors Upgrade (LIU) in order to meet the High Luminosity LHC (HL-LHC) beam requirements. At the current injection energy a large incoherent space charge tune spread limits the brightness of the beams, which is one of the main motivations to increase the injection energy to 160 MeV with the injection provided by Linac4, a new H⁻ linear accelerator. The higher injection energy will allow doubling the beam intensity while maintaining a space charge tune spread similar to current values. The degradation of the beam brightness due to the tune spread can be minimized with a proper choice of working point and an efficient compensation of resonances. In this paper, we present the measurement of the betatronic resonances in the four rings of the PSB at 160 MeV before the Long Shutdown 2, as well as the results of a proposed compensation scheme. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1054 EP - 1057 KW - resonance KW - space-charge KW - injection KW - proton KW - emittance DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS086 UR - http://jacow.org/ipac2019/papers/mopts086.pdf ER - TY - CONF AU - Antoniou, F. AU - Albright, S.C.P. AU - Asvesta, F. AU - Bartosik, H. AU - Di Giovanni, G.P. AU - Forte, V. AU - Fraser, M.A. AU - Garcia-Tabares, A. AU - Huschauer, A. AU - Mikulec, B. AU - Prebibaj, T. AU - Santamaría García, A. AU - Skowroński, P.K. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Transverse Emittance Studies at Extraction of the CERN PS Booster J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Transverse emittance discrepancy in the beam transfer between the Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS) is observed in operational conditions for the LHC beams at CERN. The ongoing LHC Injectors Upgrade (LIU) project requires a tight budget for beam degradation along the injector chain and therefore the reason for this emittance discrepancy needs to be understood. Systematic measurements have been performed for various beam characteristics (beam intensity, transverse and longitudinal emittance). In this paper, a comparison between the emittance measurements using all available beam instrumentation with different emittance computation algorithms is presented. The results are compared to measurements at PS injection. Furthermore, the impact on the LIU project requirements for the emittance preservation along the LHC Injectors Complex is discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1058 EP - 1061 KW - emittance KW - optics KW - operation KW - booster KW - injection DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS087 UR - http://jacow.org/ipac2019/papers/mopts087.pdf ER - TY - CONF AU - Carlà, M. AU - Bartosik, H. AU - Beck, M.S. AU - Carver, L.R. AU - Kain, V. AU - Kotzian, G. AU - Li, K.S.B. AU - Rumolo, G. AU - Zannini, C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Transverse Beam Dynamics Studies With High Intensity LHC Beams in the SPS J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In order to reach the target beam parameters of the LHC injectors upgrade (LIU), about twice the presently operational intensity of LHC type beams has to be achieved. Although the planned upgrade of the main RF system will occur during the long shutdown, a series of measurements have been performed to assess the beam dynamics challenges with these very high intensity beams on the long SPS injection plateau. Bunch-by-bunch transverse emittance blow-up measurements suggested the presence of electron-cloud. After a period of running with the high intensity beam for a couple of days, a clear improvement of beam quality was observed which is attributed to scrubbing. In addition, a horizontal headtail instability is encountered for the usual operational settings of chromaticity and transverse damper. The stability limit as a function of chromaticity and Landau octupole settings has been explored and will be discussed, together with possible sources of the instability and mitigation strategies. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1062 EP - 1065 KW - injection KW - octupole KW - emittance KW - impedance KW - electron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS089 UR - http://jacow.org/ipac2019/papers/mopts089.pdf ER - TY - CONF AU - Carlà, M. AU - Alekou, A. AU - Bartosik, H. AU - Carver, L.R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Beam-Based Measurement of the Skew-Sextupolar Component of the Radio Frequency Field of a HL-LHC-Type Crab-Cavity J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Two High Luminosity Large Hadron Collider (LHC) type crab-cavities have been installed in the CERN SPS for testing purposes. An attempt to characterize the skew-sextupolar component of the radio frequency field of the crab-cavity (a3) has been carried out by means of beam-based techniques using turn-by-turn monitoring of the betatron motion. The skew nature of a3 couples the horizontal and vertical betatron motions through a non-linear term. Therefore by exciting the horizontal betatron motion it was possible to observe a spectral line in the vertical beam motion driven by the non-linear coupling at the characteristic frequency 2Qx. A measurement of the magnitude of a3 was thus obtained by characterizing amplitude and phase of such line. The results of the measurements are discussed here. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1066 EP - 1069 KW - cavity KW - betatron KW - sextupole KW - damping KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS090 UR - http://jacow.org/ipac2019/papers/mopts090.pdf ER - TY - CONF AU - Carra, F. AU - Bertarelli, A. AU - Gobbi, G. AU - Guardia, J. AU - Guinchard, M. AU - Harden, F.J. AU - Pasquali, M. AU - Redaelli, S. AU - Skordis, E. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Mechanical Robustness of HL-LHC Collimator Designs J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Two new absorbing materials were developed as collimator inserts to fulfil the requirements of HL-LHC higher brightness beams: molybdenum-carbide graphite (MoGr) and copper-diamond (CuCD). These materials were tested under intense beam impacts at CERN HiRadMat facility in 2015, when full jaw prototypes were irradiated. Additional tests in HiRadMat were performed in 2017 on another series of material samples, including also improved grades of MoGr and CuCD, and different coating solutions. This paper summarizes the main results of the two experiments, with a main focus on the behaviour of the novel composite blocks, the metallic housing, as well as the cooling circuit. The experimental campaign confirmed the final choice for the materials and the design solutions for HL-LHC collimators, and constituted a unique chance of benchmarking numerical models. In particular, the tests validated the selection of MoGr for primary and secondary collimators, and CuCD as a valid solution for robust tertiary collimators. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1070 EP - 1073 KW - experiment KW - site KW - proton KW - interface KW - radiation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS091 UR - http://jacow.org/ipac2019/papers/mopts091.pdf ER - TY - CONF AU - Carra, F. AU - Brodzinski, K. AU - Cano-Pleite, E. AU - Capatina, O. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Numerical and Experimental Evaluation of the DQW Crab Cavity Cryomodule Thermal Budget J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - One of the key devices of the HL-LHC project are SRF Crab Cavities. A cryomodule with two Double Quarter Wave (DQW) crab cavities has been fabricated at CERN in 2017 and successfully tested with beam in the Super Proton Synchrotron (SPS) in 2018. The aim of the present study is to present and compare the estimation of the thermal budget for the different components of the cryomodule, performed with numerical and semi-analytical methods, with the experimental measurements carried out on the cryomodule after installation in the SPS. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1074 EP - 1077 KW - cryomodule KW - cavity KW - HOM KW - radiation KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS092 UR - http://jacow.org/ipac2019/papers/mopts092.pdf ER - TY - CONF AU - Carra, F. AU - Accettura, C. AU - Beghi, M. AU - Bertarelli, A. AU - Bregliozzi, G. AU - Cattenoz, G. AU - Guardia Valenzuela, J. AU - Redaelli, S. AU - Taborelli, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Ultra-High Vacuum Characterization of Molybdenum-Carbide Graphite for HL-LHC Collimators J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In view of the High-Luminosity upgrade of the Large Hadron Collider (LHC) collimation system, a family of novel molybdenum-carbide graphite (MoGr) composites was developed to meet the challenging requirements of HL-LHC beam-halo collimation, in particular the electrical conductivity and thermo-mechanical performances. The Ultra-High Vacuum (UHV) behaviour of this material was extensively characterized to assess its compatibility with the accelerator’s specifications. The results presented in this paper correlate the outgassing behaviour with the microscopic features of MoGr compared to other graphite-based materials. Residual gas analysis (RGA) was exploited to optimize post-production treatments. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1078 EP - 1081 KW - vacuum KW - collimation KW - site KW - proton KW - collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS093 UR - http://jacow.org/ipac2019/papers/mopts093.pdf ER - TY - CONF AU - Grob, L.K. AU - Apollonio, A. AU - Charvet, C. AU - Garcia-Tabares Valdivieso, E. AU - Kos, H. AU - Neves, C. AU - Schmidt, R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Dust Analysis from LHC Vacuum System to Identify the Source of Macro-Particle-Beam-Interactions J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Since in 2010 the first sub-millisecond beam losses were observed at varying locations all along the LHC, it is well known that dust can interact with high-intensity proton beams and cause significant beam losses. Initially the sudden localized losses were enigmatic and coined the phrase ’unidentified falling objects’ (UFOs), which is still widely used. These very fast beam losses have resulted in hundreds of premature beam dumps and even magnet quenches since the start of LHC. So far, the only mitigation strategy involved an optimization of dump thresholds and the beneficial conditioning effect which leads to a reduction of the UFO rate over time. To understand the physics involved in these events and to allow an active diminution, it is essential to know the chemical composition and the size of the dust particulates interacting with the protons. The exchange of a dipole magnet offered the unique opportunity to collect dust samples from inside the LHC vacuum system. They were extracted from the various components and analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy to reveal size distribution and abundant elements. The results of this investigation will optimize the existing UFO models and the improved understanding of the phenomenon may help to prevent future performance limitations. This is also of relevance for future projects, in particular for the Future Circular Collider (FCC) under study. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1082 EP - 1085 KW - vacuum KW - beam-losses KW - operation KW - proton KW - dipole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS094 UR - http://jacow.org/ipac2019/papers/mopts094.pdf ER - TY - CONF AU - Noll, D. AU - Bellodi, G. AU - Bertolo, S.B. AU - Di Lorenzo, F.D.L. AU - Lallement, J.-B. AU - Lettry, J. AU - Lombardi, A.M. AU - Mastrostefano, C.M. AU - Mikulec, B. AU - O'Neil, M. AU - Schuh, S. AU - Wegner, R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Linac4: Reliability Run Results and Source Extraction Studies J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Linac4, a 160 MeV, 352.2 MHz linear accelerator, has been fully commissioned and will take its place as new injector to the CERN chain of accelerators during the long shutdown (LS2) in 2019-2020. In the past year, it has been continuously providing beam during a test run to assess its reliability in view of the connection to the LHC injector chain. The target reliability of more than 90% has been demonstrated during the accumulated nine months of run in 2017 and 2018. The beam quality at 160 MeV is suitable for producing all beams for the CERN physics program of today. Nevertheless, the limited peak current of 30mA might be a limitation for future high intensity programs. The bottleneck has been identified at the low energy end of the accelerator. In the meantime, beam extraction and low energy beam transport studies are ongoing at a dedicated test stand with the goal to reach beam currents from the pre-injector up to 45 mA. We will present the status of the modelling of the pre-injector and possible solutions to reach higher beam currents from the RFQ along with results from the reliability run. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1090 EP - 1093 KW - emittance KW - extraction KW - linac KW - simulation KW - plasma DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS096 UR - http://jacow.org/ipac2019/papers/mopts096.pdf ER - TY - CONF AU - Etisken, O. AU - Antoniou, F. AU - Papaphilippou, Y. AU - Tydecks, T. AU - Çiftçi, A.K. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Updates on Alternative Pre-Booster Ring Design and Wiggler Magnet Considerations of SPS for the FCC e⁺e⁻ Injector J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Future Circular e⁺e⁻ Collider (FCC- e⁺e⁻) injector complex needs to produce and to transport a high-intensity e⁺e⁻ beam at a fast repetition rate for topping up the collider at its collision energy. Two different options are under consideration as pre-accelerator before the bunches are transferred to the high-energy booster: using the existing SPS and designing a completely new ring. The purpose of this paper is to explore the needs and parameters of the existing SPS, to investigate wiggler magnet options for SPS, and provide an updated study of alternative accelerator ring design with injection and extraction energies of 6 and 20 GeV, respectively. In this study, the parameters of both choices are established, including the optics design, layout update and considerations for non-linear dynamics optimization. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1094 EP - 1097 KW - damping KW - wiggler KW - emittance KW - injection KW - extraction DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS097 UR - http://jacow.org/ipac2019/papers/mopts097.pdf ER - TY - CONF AU - Papaphilippou, Y. AU - Corsini, R. AU - Dutheil, Y. AU - Evans, L.R. AU - Goddard, B. AU - Grudiev, A. AU - Latina, A. AU - Stapnes, S. AU - Åkesson, T.P.Å. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - A Primary Electron Beam Facility at CERN J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - This paper describes the concept of a primary electron beam facility at CERN, to be used for dark gauge force and light dark matter searches. The electron beam is produced in three stages: A Linac accelerates electrons from a photo-cathode up to 3.5 GeV. This beam is injected into the Super Proton Synchrotron, SPS, and accelerated up to a maximum energy of 16 GeV. Finally, the accelerated beam is slowly extracted to an experiment, possibly followed by a fast dump of the remaining electrons to another beamline. The beam parameters are optimized using the requirements of the Light Dark Matter eXperiment, LDMX, as benchmark. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1098 EP - 1101 KW - linac KW - electron KW - injection KW - emittance KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS098 UR - http://jacow.org/ipac2019/papers/mopts098.pdf ER - TY - CONF AU - Perini, D. AU - Crawford, D.J. AU - Feng, J. AU - Gobbi, G. AU - Li, Z. AU - Liu, W. AU - Ruan, J. AU - Shao, W. AU - Stancari, G. AU - Valerio, L.R. AU - Wang, J. AU - Wang, Y. AU - Yang, Y. AU - Zhang, K. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The Development Programme of Cathodes and Electron Guns for the Hollow Electron Lenses of the High Luminosity LHC Project J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The High Luminosity LHC project (HL-LHC) foresees the construction and installation of important new equipment to increase the performance of the LHC machine. The Hollow Electron Lens (HEL) is a promising system to control the beam halo. It improves the beam collimation system of the HL-LHC and mitigates possible equipment damage in case of failure scenarios from halo losses. The halo can store up to 30 MJ energy. The specifications for this new device are quite demanding. The source, an electron gun with an annular shaped cathode, has to deliver a current up to 5 A. This is five times higher than the current in the existing electron lenses in Fermi and Brookhaven national laboratories. This note describes the programme carried out to design and test high-perveance guns equipped with two types of high-performance scandate cathodes. The size of the final gun is now considerably smaller than the one of the first prototype, allowing a reduction of diameter and cost of the superconducting magnet system used to steer the electron beam. The tests carried out at FNAL, BVERI and BJUT demonstrated that the developed cathodes fulfil the specifications and can supply a 5 A fully Space Charge Limited (SCL) current. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1102 EP - 1105 KW - cathode KW - electron KW - gun KW - luminosity KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS099 UR - http://jacow.org/ipac2019/papers/mopts099.pdf ER - TY - CONF AU - Senes, E. AU - Emery, J. AU - Forte, V. AU - Fraser, M.A. AU - Guerrero, A. AU - Huschauer, A. AU - Roncarolo, F. AU - Sirvent, J.L. AU - Skowroński, P.K. AU - Tecker, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Transverse Emittance Measurement in the CERN Proton Synchrotron in View of Beam Production for the High-Luminosity LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the framework of the LHC Injectors Upgrade project the improvements required to achieve the parameters of the future beams for the High-Luminosity LHC are being studied and implemented. In order to deliver high brightness beams, control over the beam intensity and emittance is fundamental. Therefore, a highly accurate and reliable transverse emittance measurement is essential. Presently at the CERN Proton Synchrotron, the only operationally available emittance monitors not impacting the facility beam production are the flying wire scanners used to measure the circulating beam profile. The wire scanners will be replaced with a new generation in the next two years and a prototype is already installed. The prototype has been commissioned with beams featuring a wide range of intensities and emittances. This paper evaluates the performance of the prototype with respect to the present system via beam-based measurements. The transverse emittance measurement is discussed, considering the different potential error contributions to the measurement, such as knowledge of the machine optics and the dispersive contribution to the beam size. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1106 EP - 1109 KW - emittance KW - brightness KW - proton KW - optics KW - betatron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS100 UR - http://jacow.org/ipac2019/papers/mopts100.pdf ER - TY - CONF AU - Santamaría García, A. AU - Antoniou, F. AU - Bartosik, H. AU - Briz Monago, J.A. AU - Di Giovanni, G.P. AU - Guerrero, A. AU - Hunt, J.R. AU - Mikulec, B. AU - Roncarolo, F. AU - Senes, E. AU - Vlachoudis, V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Study of the Transverse Emittance Blow-Up Along the Proton Synchrotron Booster Cycle During Wire Scanner Operation J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Transverse emittance measurements with wire scanners have been extensively studied across the accelerator complex at CERN due to their important role in characterizing the beam and their complicated modeling. In recent years, this topic has been of particular interest for the LHC Injectors Upgrade (LIU) project, where a tight transverse emittance blow-up budget between the Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS) is imposed to assure the required beam brightness for the High Luminosity LHC (HL-LHC). In order to maintain a high brightness beam, any source of emittance blow-up along the PSB cycle needs to be identified and mitigated. While wire scanners have been mostly used at extraction energy in the PSB, they can also operate along the energy cycle. The scattering of the protons with the wire increases considerably at lower energies, leading to an overestimation of the beam emittance. In this contribution we present the most recent studies, focusing on precisely quantifying the blow-up created by the flying wire with measurements in an optimized set-up and compared to FLUKA simulations. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1110 EP - 1113 KW - emittance KW - simulation KW - proton KW - scattering KW - brightness DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS101 UR - http://jacow.org/ipac2019/papers/mopts101.pdf ER - TY - CONF AU - Skowroński, P.K. AU - Giovannozzi, M. AU - Huschauer, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Linear and Non-Linear Optics Measurements in PS using Turn-by-Turn BPM Data J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - For the first time, the optics of the CERN Proton Synchrotron (PS) was measured using turn-by-turn BPM data of forced betatron oscillations excited with an AC dipole. We report results of phase advance and beta beating measurements. Linear coupling was globally minimized along the machine by measuring and correcting coupling resonance driving terms. Finally, non-linear properties of the ring were probed looking at third and fourth order resonance driving terms and amplitude detuning. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1114 EP - 1117 KW - injection KW - optics KW - coupling KW - sextupole KW - betatron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS102 UR - http://jacow.org/ipac2019/papers/mopts102.pdf ER - TY - CONF AU - Miyamoto, R. AU - Bebb, R.E. AU - Bergman, E.C. AU - Bergstrom, I. AU - Bertrand, B. AU - Celona, L. AU - Danared, H. AU - Derrez, C.S. AU - Donegani, E.M. AU - Eshraqi, M. AU - Esteban Müller, J.F. AU - Fay, T. AU - Grishin, V. AU - Gålnander, B. AU - Haghtalab, S. AU - Hassanzadegan, H. AU - Jansson, A. AU - Kocevar, H. AU - Laface, E. AU - Levinsen, Y. AU - Mansouri, M. AU - Martins, C.A. AU - Martins, J.P.S. AU - Milas, N. AU - Muñoz, M. AU - Neri, L. AU - Nilsson, E. AU - Plostinar, D.C. AU - Rosati, C. AU - Shea, T.J. AU - Sosa, A.G. AU - Tarkeshian, R. AU - Tchelidze, L. AU - Thomas, C.A. AU - van Velze, P.L. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - First Results of Beam Commissioning on the ESS Site for the Ion Source and Low Energy Beam Transport J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The European Spallation Source (ESS), currently under construction in Lund, Sweden, will be a spallation neutron source driven by a proton linac of an unprecedented 5 MW beam power. Such a high power requires its ion source (IS) to produce proton beam pulses at 14 Hz with a high peak current more than 62.5 mA and a long plateau up to §I{3}{ms}. The IS and the following low energy beam transport (LEBT) section were manufactured and tested with beam to meet ESS requirements at INFN-LNS and delivered to ESS towards the end of 2017. Beam commissioning of these two sections on the ESS site has started in September 2018 and will continue until the end of June 2019. This paper provides an overview on this first beam commissioning period at ESS and also presents results of IS characterization and testing on LEBT functionalities. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1118 EP - 1121 KW - LEBT KW - MMI KW - solenoid KW - site KW - ion-source DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS103 UR - http://jacow.org/ipac2019/papers/mopts103.pdf ER - TY - CONF AU - Vadai, M. AU - Alomainy, A. AU - Damerau, H. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Barrier Bucket Studies in the CERN PS J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Part of the residual beam loss during the Multi-Turn Extraction (MTE) of fixed target beams from the CERN Proton Synchrotron (PS) can be attributed to kicker magnets switching while the beam is coasting with the main RF systems off before extraction. Generating a barrier bucket to deplete the longitudinal line density of the coasting beam during the kicker rise time can reduce these losses. Beam tests have been performed with an existing Finemet cavity in the PS, which is normally operated as a wideband feedback kicker. To drive the cavity, a beam synchronous waveform synthesizer based on programmable logic has been developed. It produces a pre-distorted signal which ideally results in a single period sinusoidal voltage pulse with programmable parameters at the gap of the cavity, once or multiple times per revolution. The modelling of the behavior of the power amplifier and the cavity is essential to achieve an anti-symmetric voltage pulse with little pre- and post-pulse ripple. The design of the beam-synchronous waveform generator is presented together with results from initial beam studies with the created barrier buckets in the PS. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1128 EP - 1131 KW - cavity KW - proton KW - LLRF KW - ISOL KW - kicker DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS106 UR - http://jacow.org/ipac2019/papers/mopts106.pdf ER - TY - CONF AU - Vadai, M. AU - Alomainy, A. AU - Damerau, H. AU - Gilardoni, S.S. AU - Giovannozzi, M. AU - Huschauer, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Beam Manipulations With Barrier Buckets in the CERN PS J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A barrier bucket scheme is being considered to reduce losses during the Multi-Turn Extraction from the CERN Proton Synchrotron to the Super Proton Synchrotron for the fixed-target physics programme. For effective loss reduction, the extraction kicker has to be triggered during the gap at the time of the longitudinal barrier. Initial beam studies at injection energy and with low intensity beams allowed to fully qualify an existing wide-band cavity to generate one or multiple beam synchronous pulses per turn. Bunch-length stretching and shortening have been exercised with barriers moving in azimuth with respect to the beam. The encouraging results obtained at injection energy guided the implementation of a de-bunching manipulation at higher energy to move all bunches into a single barrier bucket. Beam measurements at a momentum of 14GeV/c, varying intensity and the width of the barrier, demonstrate that a quasi-constant longitudinal line density and an almost fully depleted gap can be achieved at highest intensities. The contribution summarises the results of the beam studies at high energy together with some observations related to the Multi-Turn Extraction. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1132 EP - 1135 KW - extraction KW - synchrotron KW - proton KW - operation KW - cavity DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS107 UR - http://jacow.org/ipac2019/papers/mopts107.pdf ER - TY - CONF AU - Lari, L. AU - Cerutti, F. AU - Esposito, L.S. AU - Garcia, F.G. AU - He, Y. AU - Kourbanis, I. AU - Mokhov, N.V. AU - Pozdeyev, E. AU - Rakhno, I.L. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - FLUKA-MARS15 Simulations To Optimize the Fermilab PIP-II Movable Beam Absorber J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - PIP-II is the Fermilab’s flagship project to provide powerful, high-intensity proton beams to the laboratory’s experiments. The heart of the PIP-II project is an H⁻ 800 MeV superconducting linear accelerator. In order to commission the beam and operate safely the linac, several constraints were evaluated. The design of a movable 5 kW beam absorber was finalized to allow staged beam commissioning in different linac locations. Prompt and residual radiation levels were calculated, and radiation shields were optimized to keep those values within the acceptable levels in the areas surrounding beam absorber. Monte Carlo calculations with FLUKA and MARS15 codes are presented in the paper to support these studies. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1136 EP - 1139 KW - linac KW - MMI KW - shielding KW - radiation KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS110 UR - http://jacow.org/ipac2019/papers/mopts110.pdf ER - TY - CONF AU - Azzopardi, G. AU - Muscat, A. AU - Redaelli, S. AU - Salvachua, B. AU - Valentino, G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Operational Results of LHC Collimator Alignment Using Machine Learning J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A complex collimation system is installed in the Large Hadron Collider to protect sensitive equipment from unavoidable beam losses. The collimators are positioned close to the beam in the form of a hierarchy, which is guaranteed by precisely aligning each collimator with a precision of a few tens of micrometers. During past years, collimator alignments were performed semi-automatically*, such that collimation experts had to be present to oversee and control the alignment. In 2018, machine learning was introduced to develop a new fully-automatic alignment tool, which was used for collimator alignments throughout the year. This paper discusses how machine learning was used to automate the alignment, whilst focusing on the operational results obtained when testing the new software in the LHC. Automatically aligning the collimators decreased the alignment time at injection by a factor of three whilst maintaining the accuracy of the results. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1208 EP - 1211 KW - alignment KW - injection KW - software KW - collimation KW - MMI DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUZZPLM1 UR - http://jacow.org/ipac2019/papers/tuzzplm1.pdf ER - TY - CONF AU - Bilgen, S. AU - Baglin, V. AU - Bruni, C. AU - Mercier, B. AU - Sattonnay, G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Dynamic Pressure in the LHC - Influence of Ions Induced by Ionization of Residual Gas by Both the Proton Beam and the Electron Cloud J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Ultra-High Vacuum is an essential requirement to reach design performances in high-energy particle colliders. For the future HL-LHC or FCC study, the understanding of the beam interactions with the vacuum chamber is fundamental to provide solutions to mitigate the pressure rises induced by electronic, photonic and ionic molecular desorption. Studies were performed on the ions, produced by molecular ionization generated by the proton beam and the electron cloud, and stimulating molecular desorption by the surface bombardment. In-situ measurements were carried out, on the LHC Vacuum Pilot Sector (VPS)*, to monitor the dynamic pressure, and to collect the electrical signals due to the electron cloud and to the ions interacting with the vacuum chamber walls. Experimental measurements of electrical signals recorded by copper electrodes were compared to calculations taking into account both the Secondary Electron Yield of copper and electron energy distribution. Finally, it seems that copper electrodes were not fully conditioned and an ion current could be estimated. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1236 EP - 1239 KW - electron KW - proton KW - vacuum KW - experiment KW - ECR DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPMP004 UR - http://jacow.org/ipac2019/papers/tupmp004.pdf ER - TY - CONF AU - Sattonnay, G. AU - Baglin, V. AU - Bilgen, S. AU - Mercier, B. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - DYVACS (DYnamic VACuum Simulation) Code: Calculation of Gas Density Profiles in Presence of Electron Cloud J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The computation of residual gas density profiles in particle accelerators is an essential task to optimize beam pipes and vacuum system design. In a hadron collider such as the LHC, the beam induces dynamic effects due to ion, electron and photon-stimulated gas desorption. The well-known VASCO* code developed at CERN in 2004 (and then PyVASCO**) is already used to estimate vacuum stability and density profiles in steady state conditions. Nevertheless, some phenomena are not taken into account such as the ionization of residual gas by the electron clouds. Therefore, we propose an upgrade of this code by introducing electron cloud maps*** to estimate the electron density and the ionization of gas by electrons, leading to an increase of both electron- and ion-induced desorption. Results obtained with the new code (called DYVACS for DYnamic VACuum Simulation) will be compared to pressure measurements in the VPS sector**** of the LHC. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1244 EP - 1247 KW - electron KW - vacuum KW - proton KW - photon KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPMP007 UR - http://jacow.org/ipac2019/papers/tupmp007.pdf ER - TY - CONF AU - Di Cosmo, M. AU - Gaime, T.G. AU - Todd, B. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - A Modular Optical Firing Interface for CERN’s Generic Power Converter Control Platform J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The power converters group at CERN has developed a third generic converter controller (FGC3) and regulation platform (RegFGC3), capable of controlling any of CERN’s power converters. This platform provides electrical connections to the low-level control elements of power converters, and in some cases a galvanic isolation is required between the converter controller output, and the power converter under control. To meet these requirements, a generic modular optical firing platform has been developed, which converts the electrical firing pulses from the RegFGC3 and FGC3 platforms into optical drive signals. Designed to be fully scalable, this platform provides various protection mechanisms to verify the integrity of the firing information. For example, checking for illegal firing states, dead-time, and drive errors. This paper describes the modular optical firing interface, the basic principles, and the configurations which are in use, or are planned to be used at CERN. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1315 EP - 1318 KW - controls KW - interface KW - ISOL KW - status KW - electron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPMP034 UR - http://jacow.org/ipac2019/papers/tupmp034.pdf ER - TY - CONF AU - Kersevan, R. AU - Garion, C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Design of the Vacuum System of the FCC-ee Electron-Positron Collider J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Future Circular Collider (FCC) Design Study includes the twin storage ring (FCC-ee) where electrons and positrons are stored and made to collide inside two detectors. The vacuum system of FCC-ee must be designed in order to deal with a lower-energy (45.6 GeV), high-current (1390 mA) Z-pole machine and at a later stage with a higher-energy (182.5 GeV) low-current (5.4 mA). The former machine is the most challenging one from the point of view of vacuum, since the photon-stimulated desorption (PSD) generated by the copious synchrotron radiation (SR) fans is quite large. While several concepts have been considered at the beginning, the design retained for the Conceptual Design Report (CDR) is one where the cross-section of the vacuum chamber (VC) in the arcs is a scaled-down version of the one implemented in the SUPERKEKB collider. Contrary to SUPERKEKB tough, the SR fans are absorbed by many short absorbers, with average spacing of 5.8 m. This allow a localization of the PSD gas load and to place lumped pumps in front of the SR absorbers, to maximize the pumping efficiency. The VC design is compatible with the design of the common-yoke dipoles and quadrupoles. The VC material is copper alloy. Optimization of the pressure profiles has been carried out by means of extensive coupled montecarlo simulations, for SR and molecular flow. For the higher energy versions of the machine, for which the SR spectra are characterized by critical energies well above the Compton edge, the localized absorbers facilitate also shielding the tunnel and any radiation-sensitive machine components from X-ray photon damage, by installing short high-Z material around the absorbers. The major features of the CDR relevant for vacuum will be highlighted in the paper. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1319 EP - 1322 KW - collider KW - vacuum KW - photon KW - dipole KW - quadrupole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPMP035 UR - http://jacow.org/ipac2019/papers/tupmp035.pdf ER - TY - CONF AU - Gonzalez, L.A. AU - Baglin, V. AU - Bellafont, I. AU - Casalbuoni, S. AU - Chiggiato, P. AU - Garion, C. AU - Huttel, E. AU - Kersevan, R. AU - Pérez, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Results on the FCC-hh Beam Screen Sawtooth at the Kit Electron Storage Ring Kararesults on the Fcc-Hh Beam Screen Sawtooth at the Kit Electron Storage Ring Kara J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the framework of the EuroCirCol collaboration (work package 4 "Cryogenic Beam Vacuum System"), the fabrication of the FCC-hh beam screen (BS) prototype has been carried out with the aim of testing it at room temperature on the Karlsruhe Institute of Technology (KIT) 2.5 GeV electron storage ring KARA (KArlsruhe Research Accelerator) light source. The BS prototype was tested on a beamline installed by the collaboration, named as BEam Screen TEstbench EXperiment (BESTEX). KARA has been chosen because its synchrotron radiation (SR) spectrum, photon flux and power match quite well the one foreseen for the 50+50 TeV FCC-hh proton collider. The BS prototype (2 m in length) was manufactured according to the base line design (BD) of the FCC-hh BS. It implements a saw-tooth profile designed to absorb the SR generated at the bending magnets. Also, a laser-ablated anti-electron cloud surface texturing [2] was applied at the BS inner walls. We present here the results obtained at BESTEX and the comparison of the results obtained during irradiation of the saw-tooth profile at different geometric configurations. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1323 EP - 1326 KW - photon KW - radiation KW - vacuum KW - experiment KW - electron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPMP036 UR - http://jacow.org/ipac2019/papers/tupmp036.pdf ER - TY - CONF AU - Kersevan, R. AU - Ady, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Recent Developments of Monte-Carlo Codes Molflow+ and Synrad+ J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Molflow+ and Synrad+ are Monte Carlo simulation tools for ultra-high vacuum and synchrotron radiation, respectively. Over the years they have become a common tool for designing and analysing the vacuum system of particle accelerators. This contribution gives a short summary about new features added since IPAC-14*. Some highlights: In traditional Monte Carlo simulations, one simulated ’virtual’ particle represents a given number of physical molecules or photons. This is a weakness where the pressure or flux of the simulated system spans across multiple orders of magnitude. Synrad now supports low flux mode, a weighed Monte Carlo technique where the represented number of photons is reduced at every reflection, providing significantly better statistics at low flux regions. As for Molflow+, angle maps allow recording the molecules, directional distribution at any point, and then desorb a reduced gas quantity according to the recording. In linear systems, this allows iterative simulations that have been proven to treat systems up to 7 orders of magnitude of pressure difference. Without the new technique the computing time would be prohibitively slow on desktop computers, which is what most users of the two codes use. Both codes now have a built-in geometry builder that allows creating simple models through a set of 3D operations, and modifying those imported from CAD tools. Molflow+ has recently become open source, and it has been made compatible with, and tested on different versions of Linux and macOS. Examples of application of Molflow+ to novel Beam Gas Curtain detector and the design of the FCC-ee vacuum system will be given, alongside with some benchmarking runs against data published in literature. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1327 EP - 1330 KW - simulation KW - vacuum KW - photon KW - synchrotron KW - synchrotron-radiation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPMP037 UR - http://jacow.org/ipac2019/papers/tupmp037.pdf ER - TY - CONF AU - Bellafont, I. AU - Kersevan, R. AU - Mether, L. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Summary of Modelling Studies on the Beam Induced Vacuum Effects in the FCC-hh J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - EuroCirCol is a conceptual design study of a Future Circular Collider (FCC-hh) which aims to expand the current energy and luminosity frontiers that the LHC has established. The vacuum chamber of this 50 TeV, 100 km collider, will have to cope with unprecedented levels of synchrotron radiation power for proton colliders, dealing simultaneously with a tighter magnet aperture. Since the high radiation power and photon flux will release large amounts of gas into the system, the difficulty to keep a low level of residual gas density increases considerably compared with the LHC. This article presents a study of the beam induced vacuum effects for the FCC-hh novel conditions, the different phenomena which, owing to the presence of the beam, have an impact on the vacuum level of the accelerator. To achieve this, a novel beam screen has been proposed, featuring specific mitigating measures aimed at dealing with the beam induced effects. It is concluded that thanks to the new beam screen design, the vacuum level in the FCC-hh shall be adequate, allowing to reach the molecular density requirement of better than 10¹⁵ H₂/m3 with baseline beam parameters within the first months of conditioning. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1331 EP - 1334 KW - vacuum KW - electron KW - photon KW - collider KW - synchrotron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPMP038 UR - http://jacow.org/ipac2019/papers/tupmp038.pdf ER - TY - CONF AU - Nicoletti, A. AU - Martino, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Data-driven Controller Design Using the CERN Power Converter Control Libraries (CCLIBS) J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The data-driven control approach is a control methodology in which a controller is designed without the need of a model. Parametric uncertainties and the associated unmodeled dynamics are therefore irrelevant; the only source of uncertainty comes from the measurement process. The CERN Power Converter Control Libraries (CCLIBS) have been updated to include data-driven H-infinity control methods recently proposed in literature. In particular, a two-step convex optimization algorithm is performed for obtaining the 2-degree-of-freedom controller parameters. The newly implemented tools in CCLIBS can be used both for frequency response measurement of the load and for controller synthesis. A case study is presented where these tools are used for an application in the CERN East Area Renovation Project for which a high-precision 900 A trapezoidal current pulse is required with 450 ms flat-top and 350 ms ramp-up and ramp-down times. The tracking error must remain within ± 100 parts-per-million (ppm) during the flat-top (before the ramp-down phase starts). The magnet considered in the case study is of non-laminated iron type, hence the necessity of data-driven techniques since the dynamics of such a magnet is difficult to be modeled accurately (due to eddy currents losses). The Power Converter used is a SIRIUS 2P (with a current and voltage rating of 400 Arms and 450 V, respectively) whose digital control loop is regulated at a sampling rate of 5 kS/s. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1335 EP - 1337 KW - controls KW - experiment KW - interface KW - factory KW - survey DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPMP039 UR - http://jacow.org/ipac2019/papers/tupmp039.pdf ER - TY - CONF AU - Martino, M. AU - Arpaia, P. AU - Ierardi, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Impact of Flux Jumps on High-Precision Powering of Nb₃Sn Superconducting Magnets J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Nb₃Sn superconducting magnets represent a technology enabler for future high-energy particle accelerators. A possible impediment, though, comes from flux jumps that, so far, could not be avoided by design unlike for NbTi technology. However, the impact of flux jumps on the powering has not been properly investigated to date. Flux jumps appear during current ramps at relatively low value of current and tend to disappear towards nominal current. They are usually detected as voltage jumps between different magnet coils but they might also produce overall voltage jumps across the magnet electrical terminals. Such jumps might perturb the power converter feedback control loop and therefore potentially jeopardize its precision performance during energy ramps. This work aims at : (i) presenting preliminary experimental test results on some HL-LHC Nb₃Sn model and prototype magnets, and (ii) attempting to build a simplified electrical model of the flux jumps (with focus only at its interaction with the power converter feedback control loop). Such work is a starting point for outlining possible power converters control strategies able to minimize flux jumps impact on high-precision powering of Nb₃Sn superconducting magnets. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1338 EP - 1340 KW - experiment KW - simulation KW - controls KW - superconducting-magnet KW - superconductivity DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPMP040 UR - http://jacow.org/ipac2019/papers/tupmp040.pdf ER - TY - CONF AU - Kaabi, W. AU - Angal-Kalinin, D. AU - Bogacz, S.A. AU - Bousson, S. AU - Brüning, O.S. AU - Calaga, R. AU - Chaikovska, I. AU - Dassa, L. AU - Gerigk, F. AU - Hounsell, B. AU - Hutton, A. AU - Jensen, E. AU - Klein, M. AU - Levichev, E.B. AU - Longuevergne, D. AU - Marhauser, F. AU - McKenzie, J.W. AU - Militsyn, B.L. AU - Olivier, G. AU - Olry, G. AU - Pupkov, Yu.A. AU - Rimmer, R.A. AU - Stocchi, A. AU - Tennant, C. AU - Thonet, P.A. AU - Vallerand, C. AU - Welsch, C.P. AU - Williams, P.H. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - PERLE: A High Power Energy Recovery Facility J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - PERLE is a proposed high power Energy Recovery Linac, designed on multi-turn configuration, based on SRF technology, to be hosted at Orsay-France in a col-laborative effort between local laboratories: LAL and IPNO, together with an international collaboration involv-ing today: CERN, JLAB, STFC ASTeC Daresbury, Liverpool University and BINP Novosibirsk. PERLE will be a unique leading edge facility designed to push advances in accelerator technology, to provide intense and highly flexible test beams for component development. In its final configuration, PERLE provides a 500 MeV elec-tron beam using high current (20 mA) acceleration during three passes through 801.6 MHz cavities. This presenta-tion outlines the technological choices, the lattice design and the main component descriptions. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1396 EP - 1399 KW - cavity KW - linac KW - cryomodule KW - injection KW - gun DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPGW008 UR - http://jacow.org/ipac2019/papers/tupgw008.pdf ER - TY - CONF AU - D'Auria, G. AU - Aicheler, M. AU - Aksoy, A.A. AU - Alesini, D. AU - Apsimon, R. AU - Arnesano, J.M. AU - Bellaveglia, M. AU - Bernhard, A. AU - Bosco, F. AU - Buonomo, B. AU - Burt, G. AU - Calvi, M. AU - Cardelli, F. AU - Castaneda Cortes, H.M. AU - Castilla, A. AU - Clarke, J.A. AU - Croia, M. AU - Cross, A.W. AU - Dattoli, G. AU - Di Mitri, S. AU - Diomede, M. AU - Dowd, R.T. AU - Dunning, D.J. AU - Fang, W.D. AU - Faus-Golfe, A. AU - Ferrario, M. AU - Ficcadenti, L. AU - Gallo, A. AU - Gazis, E.N. AU - Gazis, N. AU - Geometrante, R. AU - Gethmann, J. AU - Giribono, A. AU - Goryashko, V.A. AU - Han, Y. AU - Jacewicz, M. AU - Janssen, X.J.A. AU - Kokole, M. AU - Latina, A. AU - Liu, X. AU - Luiten, O.J. AU - Marcos, J. AU - Marín, E. AU - Mostacci, A. AU - Mutsaers, P.H.A. AU - Muñoz Horta, R. AU - Nguyen, F. AU - Palumbo, L. AU - Petralia, A. AU - Piersanti, L. AU - Priem, J.M.A. AU - Pérez, F. AU - Rochow, R.A. AU - Rossi, C. AU - Ruber, R.J.M.Y. AU - Schmidt, T. AU - Schulte, D. AU - Spataro, B. AU - Stapnes, S. AU - Stragier, X.F.D. AU - Taylor, G. AU - Thompson, N. AU - Vaccarezza, C. AU - Wu, X.W. AU - Wuensch, W. AU - Zhang, K. AU - Zhang, L. AU - Zhu, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The CompactLight Design Study Project J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The H₂020 CompactLight Project (www. CompactLight.eu) aims at designing the next generation of compact X-rays Free-Electron Lasers, relying on very high gradient accelerating structures (X-band, 12 GHz), the most advanced concepts for bright electron photo injectors, and innovative compact short-period undulators. Compared to existing facilities, the proposed facility will benefit from a lower electron beam energy, due to the enhanced undulators performance, and will be significantly more compact, with a smaller footprint,  as a consequence of the lower energy and the high-gradient X-band structures. In addition, the whole infrastructure will also have a lower electrical power demand as well as lower construction and running costs. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1756 EP - 1759 KW - FEL KW - linac KW - electron KW - undulator KW - brightness DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB032 UR - http://jacow.org/ipac2019/papers/tuprb032.pdf ER - TY - CONF AU - Marín, E. AU - Aksoy, A.A. AU - Di Mitri, S. AU - Latina, A. AU - Muñoz Horta, R. AU - Pérez, F. AU - van der Geer, S.B. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Start-to-End Simulations of the Compact Light Project Based on an S-Band Injector and an X-Band LINAC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In this paper we report the start-to-end simulation results of one of the options under consideration for the CompactLight Project (XLS). The XLS is a hard X-ray Free Electron Laser under design, using the latest concepts for bright electron photo injectors, very high-gradient X-band structures, and innovative short-period undulators. Presently there exist various tracking codes to conduct the design process. Therefore identifying the most convenient code is of notable importance. This paper compares the tracking codes, Placet and General Particle Tracer, using the XLS lattice based on a S and X-band Injector. The calculation results in terms of beam quality and tracking performance of a full 6-D simulation are presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1836 EP - 1839 KW - lattice KW - linac KW - FEL KW - cavity KW - electron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB074 UR - http://jacow.org/ipac2019/papers/tuprb074.pdf ER - TY - CONF AU - Zimmermann, F. AU - Aksakal, H. AU - Aksoy, A.A. AU - Nergiz, Z. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Free Electron Laser Driven by a High-Energy High-Current Energy-Recovery Linac J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The proposed electron-hadron collider LHeC, based on an energy recovery linac, employs an electron beam of 20 mA current at an energy of tens of GeV. This electron beam could also be used to drive a free electron laser (FEL) operating at sub-Angstrom wavelengths. Here we demonstrate that such FEL would have the potential to provide orders of magnitude higher peak power, peak brilliance and average brilliance, than any other FEL, either existing or proposed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1844 EP - 1847 KW - FEL KW - electron KW - radiation KW - linac KW - undulator DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB076 UR - http://jacow.org/ipac2019/papers/tuprb076.pdf ER - TY - CONF AU - Salvant, B. AU - Amorim, D. AU - Antipov, S.A. AU - Arsenyev, S. AU - Beck, M.S. AU - Biancacci, N. AU - Brüning, O.S. AU - Campelo, J.V. AU - Carideo, E. AU - Caspers, F. AU - Dalascu, T. AU - Farricker, A. AU - Grudiev, A. AU - Kaltenbacher, T. AU - Koukovini-Platia, E. AU - Kramer, P. AU - Lasheen, A. AU - Migliorati, M. AU - Mounet, N. AU - Métral, E. AU - Nagaoka, R. AU - Nasr Esfahani, N. AU - Persichelli, S. AU - Popovic, B.K. AU - Rijoff, T.L. AU - Rumolo, G. AU - Shaposhnikova, E.N. AU - Smaluk, V.V. AU - Spataro, B. AU - Vaccaro, V.G. AU - Vollinger, C. AU - Wang, N. AU - White, S.M. AU - Zannini, C. AU - Zotter, B. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Building the Impedance Model of a Real Machine J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A reliable impedance model of a particle accelerator can be built by combining the beam coupling impedances of all the components. This is a necessary step to be able to evaluate the machine performance limitations, identify the main contributors in case an impedance reduction is required, and study the interaction with other mechanisms such as optics nonlinearities, transverse damper, noise, space charge, electron cloud, beam-beam (in a collider). The main phases to create a realistic impedance model, and verify it experimentally, will be reviewed, highlighting the main challenges. Some examples will be presented revealing the levels of precision of machine impedance models that have been achieved. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2249 EP - 2254 KW - impedance KW - simulation KW - wakefield KW - coupling KW - cavity DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEYPLS1 UR - http://jacow.org/ipac2019/papers/weypls1.pdf ER - TY - CONF AU - Jowett, J.M. AU - Bahamonde Castro, C. AU - Bartmann, W. AU - Bracco, C. AU - Bruce, R. AU - Coello de Portugal, J.M. AU - Dilly, J. AU - Fartoukh, S.D. AU - Fol, E. AU - Fuster-Martínez, N. AU - Garcia-Tabares, A. AU - Hofer, M. AU - Holzer, E.B. AU - Jebramcik, M.A. AU - Keintzel, J. AU - Lechner, A. AU - Maclean, E.H. AU - Malina, L. AU - Medvedeva, T. AU - Mereghetti, A. AU - Mirarchi, D. AU - Persson, T.H.B. AU - Petersen, B.Aa. AU - Redaelli, S. AU - Salvachua, B. AU - Schaumann, M. AU - Schwick, C. AU - Solfaroli, M. AU - Spitznagel, M.L. AU - Timko, H. AU - Tomás, R. AU - Wegscheider, A. AU - Wenninger, J. AU - Wollmann, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The 2018 Heavy-Ion Run of the LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The fourth one-month Pb-Pb collision run brought LHC Run 2 to an end in December 2018. Following the tendency to reduce dependence on the configuration of the preceding proton run, a completely new optics cycle with the strongest ever focussing at the ALICE and LHCb experiments was designed and rapidly implemented, demonstrating the maturity of the collider’s operating modes. Beam-loss monitor thresholds were carefully adjusted to provide optimal protection from the multiple loss mechanisms in heavy-ion operation. A switch from a basic bunch-spacing of 100 ns to 75 ns was made as the beam became available from the injector chain. A new record luminosity, 6 times the original design and close to the operating value proposed for HL-LHC, provided validation of the strategy for mitigating quenches due to bound-free pair production (BFPP) at the interaction points of the ATLAS and CMS experiments. Most of the beam parameters of the HL-LHC Pb-Pb upgrade were attained during this run and the integrated luminosity goals for the first 10 years of LHC operation were substantially exceeded. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2258 EP - 2261 KW - luminosity KW - heavy-ion KW - optics KW - experiment KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEYYPLM2 UR - http://jacow.org/ipac2019/papers/weyyplm2.pdf ER - TY - CONF AU - Sterbini, G. AU - Amorim, D. AU - Bartosik, H. AU - Bertarelli, A. AU - Bruce, R. AU - Buffat, X. AU - Carra, F. AU - Carver, L.R. AU - Cattenoz, G. AU - Effinger, E. AU - Fartoukh, S.D. AU - Fitterer, M. AU - Fuster-Martínez, N. AU - Gonzalez-Berges, M. AU - Gorzawski, A.A. AU - Gąsior, M. AU - Hemelsoet, G.H. AU - Hostettler, M. AU - Iadarola, G. AU - Jones, O.R. AU - Kaltchev, D. AU - Karastathis, N. AU - Kostoglou, S. AU - Lamas Garcia, I. AU - Levens, T.E. AU - Levichev, A.E. AU - Medina Medrano, L.E. AU - Mirarchi, D. AU - Olexa, J. AU - Papadopoulou, S. AU - Papaphilippou, Y. AU - Pellegrini, D. AU - Pojer, M. AU - Ponce, L. AU - Poyet, A. AU - Redaelli, S. AU - Rossi, A. AU - Salvachua, B. AU - Schmickler, H. AU - Schmidt, F. AU - Skoufaris, K. AU - Solfaroli, M. AU - Tomás, R. AU - Trad, G. AU - Valishev, A. AU - Valuch, D. AU - Xu, C. AU - Zamantzas, C. AU - Zisopoulos, P. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - First Results of the Compensation of the Beam-Beam Effect with DC Wires in the LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The compensation of the long-range beam-beam interactions using DC wires is presently under study as an option for enhancing the machine performance in the frame of the High-Luminosity LHC project (HL-LHC). The original idea dates back more than 15 years. After the installation of four wire prototypes in the LHC in 2018, a successful experimental campaign was performed during the last months. The experimental setup and the main results are reported in this paper. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2262 EP - 2265 KW - experiment KW - beam-beam-effects KW - operation KW - collider KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEYYPLM3 UR - http://jacow.org/ipac2019/papers/weyyplm3.pdf ER - TY - CONF AU - Charles, T.K. AU - Björklund Svensson, J. AU - Latina, A. AU - Thorin, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - First Experimental Measurements of the Caustic Nature of Trajectories in Bunch Compressors J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Theoretical advancements describing density perturbations in accelerated charge particle beams, known as caustics, has been recently developed * This proceeding describes the first experimental measurements of the caustic nature of charged particle trajectories in a particle accelerator. Caustics by their nature are discontinuities that result from small continuous perturbations of an input. Under certain conditions, small density modulations will reliably produce striking changes in the corresponding output current profile. These current modulations can shift alone the bunch with varying higher-order longitudinal dispersion. The MAX IV linac double-bend achromats provide the perfect test bed for experimentally verifying how the caustic lines evolve. The natural amplification of small perturbations makes caustics an attractive diagnostic tool, and effective tool for characterise the bunch compressors. This approach also allows us to modify and improve the longitudinal charge profile, removing current spikes or creating tailor shaped current profiles. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2270 EP - 2273 KW - linac KW - electron KW - FEL KW - experiment KW - sextupole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEYYPLS2 UR - http://jacow.org/ipac2019/papers/weyypls2.pdf ER - TY - CONF AU - Albright, S.C.P. AU - Angoletta, M.E. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Frequency Modulated Capture of Cooled Coasting Ion Beams J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Transverse space charge effects in the Low Energy Ion Ring (LEIR) at CERN have been shown to be a major source of particle losses, which can be mitigated with a larger RMS longitudinal emittance. However, due to electron cooling during the injection plateau, the longitudinal density is very high prior to RF capture. In addition there is an uncontrolled cycle to cycle variation in the revolution frequency of the coasting beam on the flat bottom, which degrades the beam quality at capture. In this paper we show that applying an RF frequency modulation during the capture process allows both a controlled blow-up of the longitudinal emittance and a very good reproducibility in the longitudinal distribution, which in turn improves beam transmission through the machine. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2356 EP - 2358 KW - emittance KW - low-level-rf KW - injection KW - operation KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP021 UR - http://jacow.org/ipac2019/papers/wepmp021.pdf ER - TY - CONF AU - Balhan, B. AU - Baud, C. AU - Borburgh, J.C.C.M. AU - Fraser, M.A. AU - Hourican, M. AU - Jorat, L.O. AU - Nuiry, F.-X. AU - Pianese, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Design and Construction of the CERN SPS Extraction Protection Elements for LIU J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - At CERN, the SPS synchrotron is equipped with two fast extraction channels towards the LHC. As a part of the LHC injector upgrade project (LIU), the protection devices upstream of the septa in both extraction channels will be upgraded. Various failure scenarios have been studied and presented in the past, but the definitive approach for the equipment protection upgrade for each channel has now been determined. This paper describes the consequences of the most significant failure scenarios and the impact of the heat deposition in the diluter. The resulting material stresses are evaluated. The detailed layout for the extraction protection equipment for each extraction channel is outlined. The final layout consists of a extended diluter in Long Straight Section (LSS) 6 (TPSG6) and the installation of an additional movable absorber (TPSC4) upstream of the quadrupole in front of the existing protection equipment in LSS 4. The detailed mechanical design of the TPSC4 and the construction status of both TPSC4 and TPSG6 are discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2359 EP - 2362 KW - extraction KW - vacuum KW - simulation KW - quadrupole KW - brightness DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP022 UR - http://jacow.org/ipac2019/papers/wepmp022.pdf ER - TY - CONF AU - Björkman, D. AU - Balhan, B. AU - Borburgh, J.C.C.M. AU - Esposito, L.S. AU - Fraser, M.A. AU - Goddard, B. AU - Stoel, L.S. AU - Vincke, H. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Alternative Material Choices to Reduce Activation of Extraction Equipment J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - At CERN, the Super Proton Synchrotron (SPS) is equipped with a resonant slow extraction system in Long Straight Section 2 (LSS2) towards the fixed target (FT) beam lines in the North Area. The extraction region provides the physics experiments with a quasi-DC flux of high-energy protons over a few seconds, which corresponds to tens of thousands of turns. The resonant slow extraction process provokes beam losses and is therefore the origin of radiation damage and the production of induced radioactivity in this region of the machine. This induced radioactivity imposed high constraints on the equipment design to be reliable to minimise the radiation exposure to personnel during machine maintenance. A detailed FLUKA model was developed in order to better understand the beam loss patterns, activation of the machine and to identify equipment components that could be optimised to reduce the residual dose related hazards. Simulations identified multiple alternative materials for extraction equipment components as well as shielding locations, which implementation could reduce residual activation hazards. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2363 EP - 2366 KW - extraction KW - shielding KW - radiation KW - vacuum KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP024 UR - http://jacow.org/ipac2019/papers/wepmp024.pdf ER - TY - CONF AU - Fraser, M.A. AU - Dutheil, Y. AU - Forte, V. AU - Guerrero, A. AU - Huschauer, A. AU - Oeftiger, A. AU - Ogur, S. AU - Roncarolo, F. AU - Senes, E. AU - Tecker, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Matching Studies Between CERN PSB and PS Through Multi-Turn Beam Profile Acquisitions J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the framework of the LHC Injectors Upgrade (LIU) project, the investigation and quantification of the optics mismatch between the CERN Proton Synchrotron Booster (PSB) and PS is a crucial step in understanding the source of horizontal emittance growth between the two machines. Extensive studies were carried out to estimate the mismatch from single-pass measurements in the transfer line and to rematch the transfer line to reduce the dispersive mismatch at PS injection while keeping the betatron matching unaltered. This paper presents the results of the data analysis of more recent multi-turn measurements, which profited from a new turn-by-turn beam profile monitor in the PS ring, to assess the achieved level of matching and corresponding emittance growth. The results confirm the improved matching and demonstrate the feasibility of the multi-turn technique as a fundamental tool that will be important for the recommissioning of the renovated transfer line after Long Shutdown 2. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2367 EP - 2370 KW - emittance KW - injection KW - optics KW - betatron KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP025 UR - http://jacow.org/ipac2019/papers/wepmp025.pdf ER - TY - CONF AU - Fraser, M.A. AU - Albright, S.C.P. AU - Antoniou, F. AU - Di Giovanni, G.P. AU - Dutheil, Y. AU - Forte, V. AU - Huschauer, A. AU - Roncarolo, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Emittance Dilution from the CERN Proton Synchrotron Booster’s Extraction Kickers J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Understanding the different sources of emittance dilution along the LHC injector chain is an important part of providing the high brightness proton beams demanded by the LHC Injectors Upgrade (LIU) project. In this context, the first beam-based measurements of the magnetic waveforms of the Proton Synchrotron Booster’s (PSB) extraction kickers were carried out and used to quantify the transverse emittance blow-up during extraction and transfer to the Proton Synchrotron (PS). In this contribution, the waveform measurement technique will be briefly outlined before the results and their implications for the LIU project and beam performance reach are discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2371 EP - 2374 KW - kicker KW - emittance KW - extraction KW - operation KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP026 UR - http://jacow.org/ipac2019/papers/wepmp026.pdf ER - TY - CONF AU - Dutheil, Y. AU - Bauche, J. AU - Dougherty, L.A. AU - Fraser, M.A. AU - Goddard, B. AU - Heßler, C. AU - Kain, V. AU - Kurdej, J. AU - Uythoven, J.A. AU - Velotti, F.M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Update on Beam Transfer Line Design for the SPS Beam Dump Facility J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The SPS Beam Dump Facility (BDF) being studied as part of the Physics Beyond Colliders (PBC) CERN project has recently reached an important milestone with the completion of the comprehensive feasibility study. The BDF is a proposed fixed target facility to be installed in the SPS North Area, to accommodate experiments such as SHiP (Search for Hidden Particles), which is most notably aiming at studying hidden sector particles. This experiment requires a high intensity slowly extracted 400 GeV proton beam with 4·10¹³ protons per 1 s spill to achieve 4·10¹⁹ protons on target per year. The extraction and transport scheme will make use of the first 600 m of the existing North Area extraction line. This contribution presents the status of the design work of the new transfer line and discusses the challenges identified. Aperture studies and failure scenarios are treated and the results discussed. In particular, interlock systems aiming at protecting critical components against the uncontrolled loss of the high energy proton beam are considered. We also present the latest results and implications of the design of a new laminated Lambertson splitter magnet to provide fast switching between the current North Area experiments and the BDF. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2375 EP - 2378 KW - target KW - proton KW - experiment KW - quadrupole KW - extraction DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP027 UR - http://jacow.org/ipac2019/papers/wepmp027.pdf ER - TY - CONF AU - Esposito, L.S. AU - Addesa, F.M. AU - Afonin, A.G. AU - Bestman, P. AU - Borg, J.E. AU - Butcher, M.E.J. AU - Calviani, M. AU - Chesnokov, Y.A. AU - Denisov, A.S. AU - Di Castro, M. AU - Donzé, M. AU - Durum, A.A. AU - Fraser, M.A. AU - Galluccio, F. AU - Garattini, M. AU - Gavrikov, Y. AU - Gilardoni, S.S. AU - Goddard, B. AU - Hall, G. AU - Iacoangeli, F. AU - Ivanov, Yu.M. AU - James, T. AU - Kain, V. AU - Kovalenko, A.D. AU - Koznov, M.A. AU - Lendaro, J. AU - Maisheev, V.A. AU - Malyarenko, L.G. AU - Masi, A. AU - Murtas, F. AU - Natochii, A. AU - Pari, M. AU - Pesaresi, M. AU - Prieto, J. AU - Rossi, R. AU - Sandomirskiy, Yu.E. AU - Scandale, W. AU - Seidenbinder, R. AU - Serrano Galvez, P. AU - Skorobogatov, V. AU - Stoel, L.S. AU - Taratin, A.M. AU - Velotti, F.M. AU - Yanovich, A.A. AU - Zhovkovska, V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Crystal for Slow Extraction Loss-Reduction of the SPS Electrostatic Septum J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The use of a bent crystal was investigated in order to reduce the losses at the CERN Super Proton Synchrotron (SPS) electrostatic septa (ZS) during the slow extraction of 400 GeV protons toward the North Area. The crystal, installed a few meters upstream the ZS, bends protons that would otherwise impinge on the ZS wires. Since particle deflection with good efficiency is achieved only when the crystal lattice is aligned within ~10 urad to the trajectory of the particles (at p = 400 GeV/c), a compact goniometer was built to allow the correct angular alignment of the crystal with respect to the incoming beam with a precision of few urad. In this paper, we report on the crystal features measured during a dedicated beam test by the UA9 experimental installation in the CERN H8 beam line. Details of the goniometer and its installation are also reported. The first results achieved during dedicated Machine Development (MD) sessions are finally presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2379 EP - 2382 KW - extraction KW - proton KW - experiment KW - ECR KW - alignment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP028 UR - http://jacow.org/ipac2019/papers/wepmp028.pdf ER - TY - CONF AU - Bracco, C. AU - Aiba, M. AU - Goddard, B. AU - Gorgisyan, I. AU - Turner, M. AU - Velotti, F.M. AU - Verra, L. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Systematic Optics Studies for the Commissioning of the AWAKE Beamline J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The commissioning of the AWAKE electron beam line was successfully completed in 2018. Despite a modest length of about 15 m, this low-energy line is quite complex and several iterations were needed before finding satisfactory agreement between the model and the measurements. The work allowed to precisely predict the size and positioning of the electron beam at the merging point with the protons inside the plasma cell, where no direct measurement is possible. All the key aspects and corrections which had to be included in the model, precautions and systematic checks to apply for the correct setup of the line are presented. The sensitivity of the ~18 MeV electron beam to various perturbations, like different initial optics parameters and beam conditions, energy jitter and drifts, earth’s magnetic field etc., is described. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2383 EP - 2386 KW - electron KW - optics KW - plasma KW - experiment KW - quadrupole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP029 UR - http://jacow.org/ipac2019/papers/wepmp029.pdf ER - TY - CONF AU - Bartmann, W. AU - Bracco, C. AU - Goddard, B. AU - Velotti, F.M. AU - Wenninger, J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - LHC Injection Losses and Trajectories During Run 1 and 2 and Outlook to Injection of HL-LHC Beams J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The LHC turn-around time is impacted by the control of injection losses and trajectories. While shot-to-shot trajectory variations dominated the injection efficiency during LHC Run 1, several improvements of hardware and operational settings allowed for a high rate of successful injections during Run 2. Injection losses and trajectories are analysed and presented for the high intensity proton runs, as well as for different beam types used from the injectors. Based on this analysis, an outlook is shown for the HL-LHC era, where double the bunch intensity will have to be injected. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2387 EP - 2390 KW - injection KW - extraction KW - kicker KW - operation KW - emittance DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP030 UR - http://jacow.org/ipac2019/papers/wepmp030.pdf ER - TY - CONF AU - Fraser, M.A. AU - Balhan, B. AU - Barna, D. AU - Bartosik, H. AU - Bernhard, J. AU - Bertone, C. AU - Björkman, D. AU - Borburgh, J.C.C.M. AU - Brugger, M. AU - Brunner, K. AU - Charitonidis, N. AU - Conan, N. AU - Cornelis, K. AU - Dutheil, Y. AU - Esposito, L.S. AU - Garcia Alia, R. AU - Gatignon, L. AU - Genton, C.M. AU - Goddard, B. AU - Heßler, C. AU - Kadi, Y. AU - Kain, V. AU - Mereghetti, A. AU - Pari, M. AU - Patecki, M. AU - Prieto, J. AU - Redaelli, S. AU - Roncarolo, F. AU - Rossi, R. AU - Scandale, W. AU - Solieri, N. AU - Spanggaard, J. AU - Stein, O. AU - Stoel, L.S. AU - Velotti, F.M. AU - Vincke, H. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - SPS Slow Extraction Losses and Activation: Update on Recent Improvements J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Annual high intensity requests of over 10¹⁹ protons on target (POT) from the CERN Super Proton Synchrotron (SPS) Fixed Target (FT) physics program continue, with the prospect of requests for even higher, unprecedented levels in the coming decade. A concerted and multifaceted R&D effort has been launched to understand and reduce the slow extraction induced radioactivation of the SPS and to anticipate future experimental proposals, such as SHiP* at the SPS Beam Dump Facility (BDF)**, which will request an additional 4·10¹⁹ POT per year. In this contribution, we report on operational improvements and recent advances that have been made to significantly reduce the slow extraction losses, by up to a factor of 3, with the deployment of new extraction concepts, including passive and active (thin, bent crystal) diffusers and extraction on the third-integer resonance with octupoles. In light of the successful tests of the prototype extraction loss reduction schemes, an outlook and implications for future SPS FT operation will be presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2391 EP - 2394 KW - extraction KW - operation KW - octupole KW - proton KW - alignment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP031 UR - http://jacow.org/ipac2019/papers/wepmp031.pdf ER - TY - CONF AU - Velotti, F.M. AU - Fraser, M.A. AU - Goddard, B. AU - Kain, V. AU - Stoel, L.S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Tracking Simulations of Shadowing Electrostatic Septum Wires by Means of Bent Crystals J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Super Proton Synchrotron (SPS) slow extraction is a third integer resonant extraction and hence suffers from high losses at the electrostatic septum (ZS). This is one of the main limiting factors for the maximum number of Protons On Target (POT) deliverable from the SPS to the North Area (NA). A concept to significantly reduce the extraction losses via shadowing of the electrostatic septum wires using an upstream bent crystal has been proposed in *, predicting a loss reduction of up to 50% for the prototype system installed in 2018. Following the successful experimental demonstration of the concept with beam **, detailed tracking simulations have been performed to fully understand the results obtained. Further insights, such as the effective ZS width and its alignment, could be deduced by exploiting the response of the extraction loss as a function of the two degrees of freedom of the crystal (position and angle). In this paper, the beam dynamics simulations are discussed together with the implementation of the bent crystal into the simulation framework. A comparison with measurements is presented before proposals for new configurations and parameters are discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2395 EP - 2398 KW - simulation KW - extraction KW - septum KW - optics KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP032 UR - http://jacow.org/ipac2019/papers/wepmp032.pdf ER - TY - CONF AU - Stoel, L.S. AU - Bartosik, H. AU - Benedikt, M. AU - Fraser, M.A. AU - Goddard, B. AU - Kain, V. AU - Velotti, F.M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Slow Extraction Loss Reduction With Octupoles at the CERN SPS J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The powering of octupoles during third-integer resonant slow extraction has been studied and recently tested with beam at the CERN Super Proton Synchrotron (SPS) in order to increase the extraction efficiency and reduce the induced radioactivity of the extraction straight. The octupoles distort the particle trajectories in phase space in such a way that the extracted separatrix is folded, which decreases the particle density impinging the wires of the extraction septum at the expense of increasing the extracted beam emittance. During experimental SPS machine studies a reduction of over 40% in the specific (per extracted proton) beam loss measured at the extraction septum was demonstrated. In this paper, the prerequisite studies needed to safely but efficiently deploy the new extraction scheme in a limited time-frame are described, the experimental results are presented and an outlook is given towards the next steps to bring slow extraction with octupoles into routine operation. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2399 EP - 2402 KW - extraction KW - septum KW - octupole KW - multipole KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP033 UR - http://jacow.org/ipac2019/papers/wepmp033.pdf ER - TY - CONF AU - Velotti, F.M. AU - Bartosik, H. AU - Buzio, M.C.L. AU - Cornelis, K. AU - Di Capua, V. AU - Fraser, M.A. AU - Goddard, B. AU - Kain, V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Characterisation of SPS Slow Extraction Spill Quality Degradation J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The main physics users of the Super Proton Synchrotron (SPS) are the experiments installed in the North Area (NA). They are supplied with slowly extracted protons or heavy ions, exploiting a third integer slow extraction to provide a 4.8 s spill. High duty cycle and constant particle flux are the main requirements. Frequent super cycle changes induce variation of the spill macro structure which directly deteriorate the final spill quality. In this paper, the source of such an effect are investigated. Results of both beam based measurements and direct magnetic measurements on the SPS reference magnets are presented. Finally, a possible strategy to counteract this effect is discussed, in order to try to remove the super cycle changes variation as cause for spill quality deterioration. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2403 EP - 2405 KW - quadrupole KW - dipole KW - flattop KW - target KW - extraction DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP034 UR - http://jacow.org/ipac2019/papers/wepmp034.pdf ER - TY - CONF AU - Pari, M. AU - Fraser, M.A. AU - Goddard, B. AU - Kain, V. AU - Stoel, L.S. AU - Velotti, F.M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Model and Measurements of CERN-SPS Slow Extraction Spill Re-Shaping - the Burst Mode Slow Extraction J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The ENUBET ("Enhanced NeUtrino BEams from kaon Tagging") Project aims at reaching a new level of precision of the short-baseline neutrino cross section measurement by using an instrumented decay tunnel. The North Area (NA) experimental facility of the Super Proton Synchrotron (SPS) offers the required infrastructure for the experiment. A new slow extraction type, consisting of bursts of many consecutive millisecond spills within one macro spill, has been modeled and tested for the ENUBET Project. The burst-mode slow extraction has been tested for the first time at CERN-SPS, and MADX simulations of the process have been developed. In this paper the experimental results obtained during the test campaign are presented along with the results of the quality of the produced spill and comparing it with predictions from simulations. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2406 EP - 2409 KW - extraction KW - experiment KW - operation KW - sextupole KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP035 UR - http://jacow.org/ipac2019/papers/wepmp035.pdf ER - TY - CONF AU - Weterings, W.J.M. AU - Bracco, C. AU - Jorat, L.O. AU - Meddahi, M. AU - Noulibos, R. AU - Van Trappen, P. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The New Injection Region of the CERN PS Booster J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - During the Long Shutdown 2 (LS2) at CERN, the new Linac4 (L4) accelerator will be connected to the PS Booster (PSB) to inject 160 MeV H⁻ beam into the 4 superposed PSB rings. In order to achieve this, we have designed, built and pre-assembled a completely new H⁻ charge-exchange injection chicane system, with a carbon stripping foil unit to convert the negative hydrogen ions into protons by stripping off the electrons. In parallel, we have built and installed a test stand in the L4 transfer line enabling us to gain valuable experience with operation of the stripping foil system and to evaluate different foil types during the L4 reliability runs. This paper describes the final design of the new PSB injection region and reports on the important test results obtained with the stripping foil test stand. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2414 EP - 2417 KW - injection KW - linac KW - proton KW - emittance KW - booster DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP039 UR - http://jacow.org/ipac2019/papers/wepmp039.pdf ER - TY - CONF AU - Wiesner, C. AU - Bartmann, W. AU - Bracco, C. AU - Calviani, M. AU - Carlier, E. AU - Ducimetière, L. AU - Frankl, M.I. AU - Fraser, M.A. AU - Gilardoni, S.S. AU - Goddard, B. AU - Gomes Namora, V. AU - Kramer, T. AU - Lechner, A. AU - Magnin, N. AU - Meddahi, M. AU - Perillo-Marcone, A. AU - Polzin, T. AU - Richtmann, L.C. AU - Rizzoglio, V. AU - Senaj, V. AU - Somoza, J.A.F. AU - Wollmann, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Machine Protection Aspects of High-Voltage Flashovers of the LHC Beam Dump Dilution Kickers J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The LHC Beam Dump System is required to safely dispose of the energy of the stored beam. In order to reduce the energy density deposited in the beam dump, a dedicated dilution system is installed. On July 14, 2018, during a regular beam dump at 6.5 TeV beam energy, a high-voltage flashover of two vertical dilution kickers was observed, leading to a voltage breakdown and reduced dilution in the vertical plane. It was the first incident of this type since the start of LHC beam operation. In this paper, the flashover event is described and the implications analysed. Circuit simulations of the current in the magnet coil as well as simulations of the resulting beam sweep pattern are presented and compared with the measurements. The criticality of the event is assessed and implications for future failure scenarios are discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2418 EP - 2421 KW - kicker KW - operation KW - simulation KW - vacuum KW - high-voltage DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP040 UR - http://jacow.org/ipac2019/papers/wepmp040.pdf ER - TY - CONF AU - Zimmermann, F. AU - Etisken, O. AU - Mounet, N. AU - Oeftiger, A. AU - Ogur, S. AU - Oide, K. AU - Papaphilippou, Y. AU - Salvant, B. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Damping Bunch Oscillations Due to Off-Axis Injection J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the FCC-ee pre-injector complex, a slightly modified SPS can serve as pre-booster. The baseline design foresees injecting the low-emittance electron and positron bunches off-axis into the SPS, and deploying strong wigglers to greatly enhance the radiation damping at the injection energy. We here compare the damping of large injection oscillations by means of radiation damping with the effect of other possible damping mechanisms such as a fast bunch-by-bunch feedback system and/or head-tail damping via nonzero chromaticity. As a by-product, we investigate the transverse beam stability. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2422 EP - 2425 KW - optics KW - injection KW - wiggler KW - damping KW - radiation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP041 UR - http://jacow.org/ipac2019/papers/wepmp041.pdf ER - TY - CONF AU - Droba, M. AU - Hübinger, C. AU - Jones, O.R. AU - Meusel, O. AU - Podlech, H. AU - Thoma, K.I. AU - Wendt, M. AU - Zimmermann, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - DEVELOPMENT OF THE ELECTRON BEAM PROBE FOR HADRON SYNCHROTRONS. J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Non-invasive diagnostics is essential to get important information about intense hadron beams, e.g. the transverse beam profile, which is indispensable in order to attain high brilliance and luminosity for upgrades on present machines and for future projects. Furthermore, it can be used to optimise parameter settings in environment of the running machine. An electron beam probe (EBP) is a beam diagnostics instrument which scans a low energy, low current electron beam through a hadron beam and obtains information from the detected response. The electrons are shot perpendicular through the hadron beam to be examined, which causes deflection in the beam potential of the intense hadron bunch, that needs to be detected and further analysed. We propose to build the EBP scanning apparatus for synchrotrons under ultra-high vacuum condition. The results of multi particle simulations evaluating limitations the expected measurement potential and limitations are presented. This work will be performed in collaboration with CERN. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2480 EP - 2483 KW - electron KW - simulation KW - hadron KW - proton KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW009 UR - http://jacow.org/ipac2019/papers/wepgw009.pdf ER - TY - CONF AU - Sieber, T. AU - De Gersem, H. AU - Golm, J. AU - Haider, D.M. AU - Marsic, N. AU - Müller, W.F.O. AU - Reeg, H. AU - Schmelz, M. AU - Schmidl, F. AU - Schwickert, M. AU - Seidel, P. AU - Stolz, R. AU - Stöhlker, T. AU - Tan, J. AU - Tranquille, G. AU - Tympel, V. AU - Zakosarenko, V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Next Generation Cryogenic Current Comparator (CCC) for nA Intensity Measurement J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A Cryogenic Current Comparator (CCC) is an extremely sensitive DC-Beam Transformer based on superconducting SQUID technology. Recently, a CCC without a toroidal core and with an axially oriented magnetic shielding has been developed at the Institute of Photonic Technologies (IPHT) Jena/Germany. It represents a compact and lightweight alternative to the ’classical’ CCC, which was originally developed at PTB Braunschweig and is successfully in operation in accelerators at GSI and CERN. Excellent low-frequency noise performance was demonstrated with a prototype of this new CCC-type. Current measurements and further tests are ongoing, first results are presented together with simulation calculations for the magnetic shielding. The construction from lead as well as simplified manufacturing results in drastically reduced costs compared to formerly used Nb-CCCs. Reduced weight also puts less constraints on the cryostat. Based on highly sensitive SQUIDs, the new prototype device shows a current sensitivity of about 6 pA/Hz1/2 in the white noise region. The measured and calculated shielding factor is ~135 dB. These values, together with a significant cost reduction - resulting also from a compact cryostat design - opens up the way for widespread use of CCCs in modern accelerator facilities. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2510 EP - 2513 KW - shielding KW - cryogenics KW - pick-up KW - coupling KW - detector DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW020 UR - http://jacow.org/ipac2019/papers/wepgw020.pdf ER - TY - CONF AU - Bergamaschi, M. AU - Aryshev, A. AU - Karataev, P. AU - Kieffer, R. AU - Lefèvre, T. AU - Lekomtsev, K. AU - Mazzoni, S. AU - Potylitsyn, A. AU - Schloegelhofer, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Recent Results using Incoherent Cherenkov Diffraction Radiation for Non-Invasive Beam Diagnostics J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - When a relativistic charged particle travels at a short distance from the surface of dielectric material Cherenkov Diffraction Radiation (ChDR) is produced inside the dielectric. Recent observation of incoherent ChDR in the visible spectrum has opened the possibility of using this radiation for non-invasive beam size and position measurements. An experimental test to study this technique for highly directional beam position measurement has been initiated on the CLEAR facility at CERN, whilst another experimental investigation is underway at the Accelerator Test Facility 2 (ATF2) at KEK, Japan, to measure the resolution limit of ChDR for beam imaging diagnostics. This contribution presents the latest experimental results from both of these test facilities. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2654 EP - 2657 KW - radiation KW - experiment KW - photon KW - diagnostics KW - beam-diagnostic DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW077 UR - http://jacow.org/ipac2019/papers/wepgw077.pdf ER - TY - CONF AU - Celeste, D. AU - Bravin, E. AU - Burger, S. AU - Roncarolo, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Development and Test of a Beam Imaging System Based on Radiation Tolerant Optical Fiber Bundles J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Many of the beam image systems at CERN are located in high radiation environments. In order to cope with this issue, VIDICON cameras are presently used but their production has been nowadays discontinued worldwide. The development of an alternative beam imaging system is described here, based on radiation tolerant optical fibre bundles. Such an optical line relays the image of a scintillating screen to a standard CMOS camera, located away from the high radiation zone. A prototype system based on a 10m long bundle with 10⁴ fibres has been tested in the TT2 transfer line at CERN. The light transmission is rather low, but is compensated by the sensitivity of the CMOS camera. The system had a field of view of 60 mm and a spatial resolution of ~1 mm. The radiation hardness of such a fiber bundle was tested at the IRMA-CEA facility in Saclay, France. The bundle was irradiated at a rate of 3.6 kGy/h for 8 consecutive day. The total integrated dose achieved was ~700 kGy, which corresponds to about ten years of operation at the beam imaging station with the highest radiation dose at CERN. While the light transmission was reduced by 50%, this is still adequate to provide acceptable images. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2658 EP - 2660 KW - radiation KW - laser KW - experiment KW - target KW - site DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW078 UR - http://jacow.org/ipac2019/papers/wepgw078.pdf ER - TY - CONF AU - Fol, E. AU - Coello de Portugal, J.M. AU - Tomás, R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Unsupervised Machine Learning for Detection of Faulty Beam Position Monitors J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Unsupervised learning includes anomaly detection techniques that are suitable for the detection of unusual events such as instrumentation faults in particle accelerators. In this work we present the application of decision trees-based algorithm to faulty BPMs detection at the LHC. This method achieves significant improvements in quality of optics measurements and allows to identify relevant signal properties that contribute to fault detection. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2668 EP - 2671 KW - optics KW - simulation KW - ISOL KW - MMI KW - ECR DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW081 UR - http://jacow.org/ipac2019/papers/wepgw081.pdf ER - TY - CONF AU - Kieffer, R. AU - Alexopoulos, A. AU - Fosse, L. AU - Gibson, S.M. AU - Gonzalez Berges, M. AU - Guerin, H. AU - Jones, O.R. AU - Marriott-Dodington, T. AU - Storey, J.W. AU - Veness, R. AU - Vlachos, S. AU - Würkner, B. AU - Zamantzas, C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The Beam Gas Vertex Profile Monitoring Station for HL-LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A new instrument is under development for the high luminosity upgrade of the Large Hadron Collider at CERN (HL-LHC) to provide non-invasive beam size measurements throughout the acceleration cycle. The Beam Gas Vertex (BGV) detector consists of a very low pressure gas target inside the beam pipe with a series of particle tracking stations located downstream. Inelastic collisions between the beam and the gas target produce secondary particles which are detected by the tracking stations. The beam size is measured from the spatial distribution of several thousand beam-gas interaction vertices, which are identified by means of the reconstructed tracks. A demonstrator device, operated over the past 3 years, has proven the feasibility of the BGV concept and has motivated development of a fully operational device for the HL-LHC. The status of current design studies for the future instrument will be presented, with particular emphasis on potential tracking detector technologies, readout schemes, and expected performance. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2672 EP - 2675 KW - detector KW - target KW - radiation KW - real-time KW - dipole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW082 UR - http://jacow.org/ipac2019/papers/wepgw082.pdf ER - TY - CONF AU - Würkner, B. AU - Alexopoulos, A. AU - Barschel, C. AU - Bay, A. AU - Blanc, F. AU - Bravin, E. AU - Bregliozzi, G. AU - Chritin, N. AU - Dehning, B. AU - Ferro-Luzzi, M. AU - Gianì, S. AU - Giovannozzi, M. AU - Girard, O. AU - Greim, R. AU - Haefeli, G.J. AU - Hopchev, P. AU - Jacobsson, R. AU - Jensen, L.K. AU - Jones, O.R. AU - Kain, V. AU - Kieffer, R. AU - Kirn, T. AU - Kuonen, A. AU - Matev, R. AU - Nakada, T. AU - Rihl, M.N. AU - Salustino Guimaraes, V. AU - Schael, S. AU - Schneider, O. AU - Tobin, M. AU - Veness, R. AU - Vlachos, S. AU - Wlochal, M. AU - Xu, Z. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Measuring Beamsize with the LHC Beam Gas Vertex Detector J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Beam Gas Vertex detector (BGV) is an innovative beam profile monitor being developed as part of the High Luminosity LHC (HL-LHC) project at CERN. The goal is to continually measure the transverse beam size by reconstructing beam-gas interaction vertices using high precision tracking detectors. To confirm the feasibility of such a device, a demonstrator based on eight modules of scintillating fiber detectors has been constructed, installed in the LHC and operated for the past 3 years. It will be shown that using the BGV the average transverse beam size can be obtained with a statistical accuracy of better than 5µm (for a gaussian beam with a σ of 200µm). This precision is obtained with an integration time of less than one minute. In addition, the BGV measures the size of individual bunches with a statistical accuracy of better than 5% within 5 minutes. The results obtained from all the data gathered over the past 3 years will be presented and compared to measurements from other beam profile monitors. Some ideas for improvements for the final HL-LHC instrument will also be discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2680 EP - 2683 KW - emittance KW - detector KW - proton KW - injection KW - luminosity DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW084 UR - http://jacow.org/ipac2019/papers/wepgw084.pdf ER - TY - CONF AU - Arteche, A. AU - Bashforth, S.E. AU - Bosco, A. AU - Gibson, S.M. AU - Krupa, M. AU - Lefèvre, T. AU - Penman, I.S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Characterisation of Electro-Optic Pickups for High Bandwidth Diagnostics at the High Luminosity LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A high bandwidth electro-optical beam position monitor is under development for the High Luminosity LHC. A series of measurements of the electro-optic signals were previously obtained by an EO-BPM prototype installed in the SPS. This paper focuses on an advanced design that would further improve the sensitivity of the pick-up by optimising the shape of the metallic electrode mounted onto the crystal. The proposed upgraded electro-optic pickups significantly increase the image field profile of the passing bunch inside a lithium niobate crystal embedded within the pickup. This work is based on parametric studies, performed using CST particle studio, investigating various electro-optic (electrode and crystal) configurations. We present the expected performance of the different designs, alongside with their evaluation on a test bench, highlighting the most relevant choice for a prototype pick-up to be installed on LHC PB - JACoW Publishing CP - Geneva, Switzerland SP - 2690 EP - 2693 KW - pick-up KW - simulation KW - proton KW - luminosity KW - ECR DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW088 UR - http://jacow.org/ipac2019/papers/wepgw088.pdf ER - TY - CONF AU - Cooke, D.A. AU - Alemany-Fernández, R. AU - Bauche, J. AU - Cascella, M. AU - Chappell, J. AU - Gorgisyan, I. AU - Gschwendtner, E. AU - Jolly, S. AU - Kain, V. AU - Keeble, F. AU - Krasny, M.W. AU - La Penna, P. AU - Mazzoni, S. AU - Petrenko, A.V. AU - Quattri, M. AU - Wing, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Calibration of the AWAKE Electron Spectrometer with Electrons Derived from a Partially Stripped Ion Beam J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The energy distribution of electrons accelerated in the wake of a self-modulated proton beam is measured using a magnetic spectrometer at AWAKE. The spectrometer was commissioned in 2017 and ran successfully throughout 2018. Imaging properties of the spectrometer system are studied via a combination of simulations and linear optics models and validated using mono-energetic electrons stripped from the partially stripped ion beam in the AWAKE beamline at CERN. These and other details of the calibration and performance will be presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2694 EP - 2696 KW - electron KW - proton KW - quadrupole KW - plasma KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW089 UR - http://jacow.org/ipac2019/papers/wepgw089.pdf ER - TY - CONF AU - Hunt, J.R. AU - Carli, C. AU - Dupuy, B. AU - Gamba, D. AU - Resta-López, J. AU - Welsch, C.P. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Emittance Evolution of Low Energy Antiproton Beams in the Presence of Deceleration and Cooling J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The commissioning of the Extra Low Energy Antiproton (ELENA) ring has been completed before the start of the second long shutdown (LS2) at CERN. First beams to an experiment in a new experimental zone have as well already been delivered. ELENA will begin distributing 100 keV cooled antiproton beams to all antimatter experiments in 2021. This contribution presents measurements made using a novel scraping algorithm capable of determining the emittance of non-Gaussian beams in the presence of dispersive effects. The emittance is sampled during various sections of the ELENA deceleration cycle, investigating the efficiency of the electron cooler and extracting additional information from the beam. The electron cooler is shown to effectively reduce the transverse phase space after blow-up during deceleration. The beam is characterised before extraction for the purpose of tracking and optimisation of the new electrostatic transfer lines currently being installed. Finally, the application of the scraping algorithm to other machines with a scraper located in a dispersive region is discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2697 EP - 2700 KW - emittance KW - electron KW - proton KW - antiproton KW - closed-orbit DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW090 UR - http://jacow.org/ipac2019/papers/wepgw090.pdf ER - TY - CONF AU - Salehilashkajani, A. AU - Ady, M. AU - Chritin, N. AU - Forck, P. AU - Glutting, J. AU - Jones, O.R. AU - Kersevan, R. AU - Marriott-Dodington, T. AU - Mazzoni, S. AU - Rossi, A. AU - Schneider, G. AU - Udrea, S. AU - Veness, R. AU - Welsch, C.P. AU - Zhang, H.D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Commissioning of the Prototype for a New Gas Curtain Beam Profile Monitor Using Beam Induced Fluorescence for HL-LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A new supersonic gas-jet curtain based beam profile monitor is under development for minimally invasive simultaneous transverse profile diagnostics of proton and electron beams, at pressures compatible with LHC. The monitor makes use of a thin gas-jet curtain angled at 45 degrees with respect to the charged particle beams. The fluorescence caused by the interaction between the curtain and the beam can then be detected using a dedicated imaging system to determine its transverse profile. This contribution details design features of the monitor, discusses the gas-jet curtain formation and presents various experimental tests, including profile measurements of an electron beam using nitrogen and neon curtains. The gas-jet density was estimated by correlating it with the number of photons detected by the camera. These measurements are then compared with results obtained using a movable pressure gauge. This monitor has been commissioned in collaboration with CERN, GSI and the University of Liverpool. It serves as a first prototype of a final design that will be placed in the LHC beam line to measure the profile of the proton beam. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2709 EP - 2712 KW - electron KW - photon KW - gun KW - background KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW093 UR - http://jacow.org/ipac2019/papers/wepgw093.pdf ER - TY - CONF AU - Zhang, H.D. AU - Ady, M. AU - Forck, P. AU - Glutting, J. AU - Jones, O.R. AU - Marriott-Dodington, T. AU - Mazzoni, S. AU - Rossi, A. AU - Salehilashkajani, A. AU - Schneider, G. AU - Udrea, S. AU - Veness, R. AU - Welsch, C.P. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Development of Supersonic Gas-Sheet-Based Beam Profile Monitors J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Non-destructive beam profile monitoring is very desirable, essentially for any particle accelerator but particularly for high-energy and high-intensity machines. Supersonic gas jet-based monitors, detecting either the ionization or fluorescence of a gas sheet interacting with the primary beam to be characterized, allow for minimally invasive measurements. They can also be used over a wide energy range, from keV to TeV beams. This contribution gives an overview of the jet-based ionization and fluorescence beam profile monitors which have been developed, built and tested at the Cockcroft Institute. It discusses gas sheet generation, vacuum considerations, choice of gas species and detection methods. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2717 EP - 2720 KW - electron KW - photon KW - background KW - radiation KW - monitoring DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW096 UR - http://jacow.org/ipac2019/papers/wepgw096.pdf ER - TY - CONF AU - Tomás, R. AU - Cardona, J.F. AU - Carlier, F.S. AU - Coello de Portugal, J.M. AU - Dilly, J. AU - Esperante Pereira, D. AU - Fol, E. AU - Fuster, J. AU - Garcia-Tabares, A. AU - Gonzalez-Iglesias, D. AU - Hoekstra, R. AU - Hofer, M. AU - Maclean, E.H. AU - Malina, L. AU - Persson, T.H.B. AU - Rodriguez, Y. AU - Skowroński, P.K. AU - Spitznagel, M.L. AU - Wegscheider, A. AU - Wenninger, J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - LHC Optics Measurement and Correction Software Progress and Plans J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - LHC Optics Measurements and Corrections (OMC) require efficient on-line software applications to acquire and analyze data and to compute the necessary corrections. During Run 2 various measurement and correction techniques have been merged to yield unprecedented optics quality, increasing the required number of steps to finalize the optics commissioning and the size of the software project. In turn, this calls for a higher level of automation, where machine learning techniques are being implemented. During the Long Shutdown 2 a large refactoring of the codes will be in place to improve performance, maintainability and extensibility. A description of the current status of the software and future plans is given. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2773 EP - 2776 KW - optics KW - software KW - coupling KW - MMI KW - GUI DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW116 UR - http://jacow.org/ipac2019/papers/wepgw116.pdf ER - TY - CONF AU - Huang, X.X. AU - Fang, W. AU - Grudiev, A. AU - Zhao, Z.T. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Study on the Design of the X-band Waveguide-damped Structure J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The design of waveguide-damped structure is optimized to reduce the magnitudes of surface electromagnetic fields and strongly suppress long-range transverse wakefields of the 380 GeV Compact Linear Collider facility currently under study. The optimization is mainly discussed with the elliptical shape of the iris, the wall shape of the damping waveguides, the position of the high-order-mode damping loads and the widths of the waveguide openings of the entire sequence of damping waveguides. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2886 EP - 2889 KW - wakefield KW - damping KW - GUI KW - HOM KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB034 UR - http://jacow.org/ipac2019/papers/weprb034.pdf ER - TY - CONF AU - Liu, J.Y. AU - Chen, H.B. AU - Grudiev, A. AU - Shi, J. AU - Zha, H. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Wakefield Suppression in the Main LINAC of the Klystron-Based First Stage of CLIC at 380 GeV J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - An alternative klystron-based scenario for the first stage of Compact Linear Collider (CLIC) at 380 GeV centre-of-mass energy was proposed. To preserve the beam stability and luminosity of CLIC, the beam-induced transverse long-range wakefield in main linac must be suppressed to an acceptable value. The design of klystron-based accelerating structure is based on waveguide damping structure (WDS). The high-order modes (HOMs) propagating into four waveguides are absorbed by HOM damping loads. In this paper, the wakefield suppression in CLIC-K based on GdfidL code simulations are presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2899 EP - 2902 KW - wakefield KW - HOM KW - GUI KW - damping KW - linac DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB043 UR - http://jacow.org/ipac2019/papers/weprb043.pdf ER - TY - CONF AU - Banon-Caballero, D. AU - Catalán Lasheras, N. AU - Faus-Golfe, A. AU - Gimeno, B. AU - Szypula, K.T. AU - Wuensch, W. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Combined Field Emission and Multipactor Simulation in High Gradient RF Accelerating Structures J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Field emitted electrons have important consequences in the operation of high-gradient RF accelerating structures both by generating so-called dark currents and initiating RF breakdown. The latter is an important limitation of the performance in such devices. Another kind of vacuum discharge that primarily affects the operation of lower-field RF components, for example those used in space applications, is multipactor. Theoretical simulations using CST Particle Studio, show that field emitted electrons generated in the high field regions of high-gradient accelerating cavities migrate to low field regions under ponderomotive forces potentially triggering multipactor there. This phenomenon is an interplay between high field and low field processes which may have as a consequence that multipactor actually affects to the performance of high-gradient cavities because field emitted electrons might reduce the timescales for the onset of multipactor. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2940 EP - 2943 KW - electron KW - multipactoring KW - simulation KW - cavity KW - GUI DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB058 UR - http://jacow.org/ipac2019/papers/weprb058.pdf ER - TY - CONF AU - Banon-Caballero, D. AU - Boronat, M. AU - Catalán Lasheras, N. AU - Faus-Golfe, A. AU - Gimeno, B. AU - Lucas, T.G. AU - Millar, W.L. AU - Paszkiewicz, J. AU - Pitman, S. AU - Sánchez Sebastián, V. AU - Vnuchenko, A. AU - Volpi, M. AU - Widorski, M. AU - Wuensch, W. AU - del Pozo Romano, V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Dark Current Analysis at CERN’s X-band Facility J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Dark current is particularly relevant during operation in high-gradient linear accelerators. Resulting from the capture of field emitted electrons, dark current produces additional radiation that needs to be accounted for in experiments. In this paper, an analysis of dark current is presented for four accelerating structures that were tested and conditioned in CERN’s X-band test facility for CLIC. The dependence on power, and therefore on accelerating gradient, of the dark current signals is presented. The Fowler-Nordheim equation for field emission seems to be in accordance with the experimental data. Moreover, the analysis shows that the current intensity decreases as a function of time due to conditioning, but discrete jumps in the dark current signals are present, probably caused by breakdown events that change the emitters’ location and intensity. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2944 EP - 2947 KW - radiation KW - operation KW - electron KW - ECR KW - linac DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB059 UR - http://jacow.org/ipac2019/papers/weprb059.pdf ER - TY - CONF AU - Paszkiewicz, J. AU - Burrows, P. AU - Wuensch, W. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Spatially Resolved Dark Current in High Gradient Traveling Wave Structures J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - High-gradient accelerating structures are known to produce field-emitted current from regions of high surface field, which are captured and accelerated by the fields within the structure. This current is routinely measured in structures under test in the CLIC high-gradient test stands using Faraday cups. This paper presents a novel technique to spatially resolve the longitudinal distribution of field emitted current by analysing downstream Faraday cup signals when the structure is fed with RF pulses much shorter than its filling time. Results from this method applied to X-band cavities operating at 100 MV/m are presented, and are compared to breakdown position distributions. A decay in emitted current as conditioning progressed in regions with a low breakdown rate and large jumps in regions with a large breakdown rate are observed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2956 EP - 2959 KW - electron KW - linac KW - diagnostics KW - site KW - collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB062 UR - http://jacow.org/ipac2019/papers/weprb062.pdf ER - TY - CONF AU - Edwards, A.V. AU - Catalán Lasheras, N. AU - Gonzalez Anton, S. AU - McMonagle, G. AU - Pitman, S. AU - Woolley, B.J. AU - del Pozo Romano, V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Connection of 12 GHz High Power RF from the XBOX 1 High Gradient Test Stand to the CLEAR Electron LINAC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A new RF system is being established at XBOX1 to drive two §I{100}{MV/m} CLIC structures in the CLEAR electron linac. In the past, these structures had been powered by RF from PET structures excited by a drive beam. This drive beam is no longer available. The upgrade will reroute power from the §I{50}{MW} klystron and pulse compressor which was previously used to power the structure in XBOX1. During the upgrade, the LLRF system will be optimised to improve the modulation of the output signals and down-mixing of the returning signals to obtain accurate phase and amplitude information. The design of the improved LLRF and software, along with phase noise measurements and comparisons with the old system are made in this paper. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2960 EP - 2963 KW - LLRF KW - klystron KW - linac KW - software KW - electron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB063 UR - http://jacow.org/ipac2019/papers/weprb063.pdf ER - TY - CONF AU - del Pozo Romano, V. AU - Bursali, H. AU - Catalán Lasheras, N. AU - Grudiev, A. AU - Pitman, S. AU - Serpico, C. AU - Syratchev, I. AU - Volpi, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - High Power Conditioning of X-Band Variable Power Splitter and Phase Shifter J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The three X-band test facilities currently at CERN aim at qualifying CLIC structures prototypes but are also exten- sively used to qualify X-band components operation at high power. In order to upgrade one of the facilities from a single test line to a double test line facility, a high power variable splitter and variable phase shifter have been designed and manufactured at CERN. They have been power tested, first in a dedicated test and also in their final configuration, to en- sure stable power operation before installing them together with an accelerating structure. In this paper, we broadly describe the RF and mechanical design, manufacturing and low power measurements agreement with simulations. We report the high power qualification of both components and their suitability to be used in existing and planned X-band facilities. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2964 EP - 2967 KW - simulation KW - klystron KW - GUI KW - ISOL KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB064 UR - http://jacow.org/ipac2019/papers/weprb064.pdf ER - TY - CONF AU - Castilla, A. AU - Burt, G. AU - Latina, A. AU - Liu, X. AU - Millar, W.L. AU - Wu, X.W. AU - Wuensch, W. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Ka-Band Linearizer Studies for a Compact Light Source J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The CompactLight project is currently developing the design of a next generation hard X-ray FEL facility, based on high-gradient X-band (12 GHz) structures, bright electron photo-injectors, and compact short period undulators. However, to improve the brightness limitations due to the non-linear energy spread of the electron bunches, a K-band (36 GHz) linearizer is being considered to provide a harmonic compensation during the bunch compression. In this paper, we analyze the feasibility of such linearizer. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2976 EP - 2979 KW - wakefield KW - klystron KW - impedance KW - FEL KW - flattop DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB068 UR - http://jacow.org/ipac2019/papers/weprb068.pdf ER - TY - CONF AU - Verdú-Andrés, S. AU - Ben-Zvi, I. AU - Burt, G. AU - Calaga, R. AU - Capatina, O. AU - Huque, N.A. AU - Li, Z. AU - McEwen, E.A. AU - Mitchell, J.A. AU - Park, H. AU - Powers, T. AU - Ratti, A. AU - Wu, Q. AU - Xiao, B.P. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Cryogenic RF Performance of Double-Quarter Wave Cavities Equipped with HOM Filters J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Crab cavities are one of the several components included in the luminosity upgrade of the Large Hadron Collider (HL-LHC). The cavities have to provide a nominal deflecting kick of 3.4 MV per cavity while the cryogenic load per cavity stays below 5 W. Cold RF tests confirmed the required performances in bare cavities, with several cavities exceeding the required voltage by more than 50%. However, the first tests of a Double-Quarter Wave (DQW) cavity with one out of three HOM filters did not reach the required voltage. The present paper describes the studies and tests conducted on a DQW cavity with HOM filter to understand the limiting factor. The recipe to meet the performance specification and exceed the voltage requirement by more than 35% is discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3043 EP - 3046 KW - cavity KW - HOM KW - operation KW - cryogenics KW - SRF DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB098 UR - http://jacow.org/ipac2019/papers/weprb098.pdf ER - TY - CONF AU - Paoluzzi, M.M. AU - Arnaudon, L. AU - Bretin, V. AU - Cuvet, Y. AU - Daricou, J. AU - Energico, S. AU - Haase, M. AU - Jones, A.J. AU - Landré, D. AU - Ohmori, C. AU - Rossi, C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The New 1-18 MHz Wideband RF System for the CERN PS Booster J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The LHC Injector Upgrade (LIU) project at CERN prepares the injectors to meet the requirements of the High Luminosity LHC. For protons, it includes the new Linac4, PS Booster (PSB), PS and SPS. Among the major changes concerning the PSB, the extraction energy increase from 1.4 GeV to 2 GeV and the higher beam intensity, made possible by the Linac4 together with the new charge exchange injection system into the PSB (2·10¹³ protons) strongly affect the RF system requirements. To deal with this more demanding beam operation, a new RF system was designed. It is based on modern magnetic alloy loaded cavities driven by solid-state amplifiers. Its wideband frequency response (1 MHz to 18 MHz) covers all the required frequency schemes. This new RF system has been produced in 2017 and 2018; installation is planned during 2019, the first year of Long Shutdown 2 (LS2) and commissioning foreseen in 2020. Most of the production and testing was outsourced to industry; parts acceptance, cavities assembly and pre-testing was done in-house. A quality assurance plan was established to achieve the required high reliability. This paper describes the procurement, production and testing strategies and methodologies. It also reports the achieved results, system performances and relevant statistics. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3063 EP - 3065 KW - cavity KW - vacuum KW - electronics KW - electron KW - impedance DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB107 UR - http://jacow.org/ipac2019/papers/weprb107.pdf ER - TY - CONF AU - Ögren, J. AU - Latina, A. AU - Schulte, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Toolbox for Optimization of RF Efficiency for Linacs J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We present a toolbox for optimizing the rf efficiency for linacs and as an example we use it to re-optimize the Compact Linear Collider booster linac. We have implemented a numerical model of a SLED-type pulse compressor that can generate a single or a double pulse. Together with the CERN CLICopti library, an RF structure parameter estimator, we created the toolbox which enables thorough optimizations of linacs in terms of RF efficiency, beam stability, and cost simultaneously, via a simple and concise Octave script. This toolbox was created for the optimization of X-band-based linacs, however it can also be used at lower frequencies, e.g. in the S- and in the C- bands of frequencies. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3074 EP - 3077 KW - linac KW - klystron KW - booster KW - RF-structure KW - software DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB113 UR - http://jacow.org/ipac2019/papers/weprb113.pdf ER - TY - CONF AU - Sjobak, K.N. AU - Burkhardt, H. AU - De Maria, R. AU - Olsen, V.K.B. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Generalised Scattering Module in SixTrack 5 J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A generalised scattering module has recently been added to SixTrack. This module enables the use of arbitrary generators and target profiles. Presently, a simple model of elastic scattering and a coupling to Pythia8 have been implemented. This makes it possible to use SixTrack for studies of aperture losses and beam lifetime as a result of beam–beam scattering. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3156 EP - 3159 KW - scattering KW - target KW - lattice KW - experiment KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS026 UR - http://jacow.org/ipac2019/papers/wepts026.pdf ER - TY - CONF AU - Argyropoulos, T. AU - Bohl, T. AU - Lasheen, A. AU - Papotti, G. AU - Quartullo, D. AU - Shaposhnikova, E.N. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Momentum Slip-Stacking in CERN SPS for the Ion Beams J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The LHC Injectors Upgrade (LIU) project at CERN aims at doubling the total intensity of the lead ion beam for the High-Luminosity (HL) LHC. Achieving this goal requires using momentum slip-stacking in the SPS, the LHC injector. Slip-stacking will be applied on an intermediate energy plateau to interleave two batches, reducing the bunch spacing from 100 ns to 50 ns and thus increasing the total number of bunches injected into the LHC. Realistic macro-particle simulations, with the present SPS impedance model are used to study and design this complicated beam manipulation. Slip-stacking can be tested experimentally only after the upgrade of the SPS 200 MHz RF system, in 2021. Preliminary, slip-stacking related beam measurements were performed at the end of 2018. In this paper both macro-particle simulations and beam measurements are reported with emphasis given on optimisation of the process, crucial to achieve the required HL-LHC parameters (bunch lengths, beam losses). PB - JACoW Publishing CP - Geneva, Switzerland SP - 3184 EP - 3187 KW - simulation KW - cavity KW - optics KW - operation KW - emittance DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS039 UR - http://jacow.org/ipac2019/papers/wepts039.pdf ER - TY - CONF AU - Hirlaender, S. AU - Bartosik, H. AU - Bellodi, G. AU - Biancacci, N. AU - Kain, V. AU - Saá Hernández, Á. AU - Scrivens, R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Energy Dependence of the Reproducibility and Injection Efficiency of the LINAC3-LEIR Complex J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - High intensities in the CERN Low Energy Ion Ring (LEIR) are achieved by stacking several multi-turn injections from the pre-accelerator LINAC3. Up to seven consecutive 200 μs long, 200 ms spaced pulses are injected from LINAC3 into LEIR. An inclined septum magnet combined with a collapsing horizontal orbit bump allows a 6-D phase space painting via a linearly ramped mean momentum along with the LINAC3 pulse and injection at high dispersion. The injected energy distribution measured by the LEIR longitudinal Schottky is correlated with the obtained injection efficiency in this paper. Studies in 2018 revealed that the achievable accumulated intensity of LEIR strongly depends on the longitudinal distribution from LINAC3, which does not stay constant. This paper summarises the experimental results and means to further improve reproducibility and high injection efficiency. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3188 EP - 3191 KW - linac KW - cavity KW - injection KW - bunching KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS040 UR - http://jacow.org/ipac2019/papers/wepts040.pdf ER - TY - CONF AU - Asvesta, F. AU - Antoniou, F. AU - Bartosik, H. AU - Di Giovanni, G.P. AU - Papaphilippou, Y. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Coupling and Space Charge Studies at the CERN PSB J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the nominal optics of the CERN PS-Booster (PSB), the fourth order coupling resonance is excited by space charge (Montague resonance) due to the same integer tune values. This resonance can be avoided by changing the tunes to different integers. A new PSB optics is presented and emittance measurements crossing the coupling resonance for the nominal and the new optics are shown. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3192 EP - 3195 KW - resonance KW - optics KW - coupling KW - emittance KW - space-charge DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS041 UR - http://jacow.org/ipac2019/papers/wepts041.pdf ER - TY - CONF AU - Saá Hernández, Á. AU - Bartosik, H. AU - Biancacci, N. AU - Hirlaender, S. AU - Moreno Garcia, D. AU - Zampetakis, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Detailed Characterisation of the LEIR Intensity Limitations for a Pb Ion Beam J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The equilibrium emittance of the Pb beam in the CERN Low Energy Ion Ring (LEIR) results from the interplay of electron cooling and heating processes, as intra-beam scattering and space charge. In this paper we present the measurements of the emittance evolution as a function of intensity, working point and resonance excitation, and compare them with the simulations of the heating processes. Optimum settings for normal and skew sextupoles have been found for the compensation of resonances excited by the lattice. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3196 EP - 3199 KW - emittance KW - resonance KW - simulation KW - injection KW - sextupole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS042 UR - http://jacow.org/ipac2019/papers/wepts042.pdf ER - TY - CONF AU - De Maria, R. AU - Andersson, J. AU - Dalena, B. AU - Field, L. AU - Giovannozzi, M. AU - Hermes, P.D. AU - Hoimyr, N. AU - Iadarola, G. AU - Kostoglou, S. AU - Maclean, E.H. AU - McIntosh, E. AU - Mereghetti, A. AU - Molson, J. AU - Olsen, V.K.B. AU - Pellegrini, D. AU - Persson, T. AU - Pugnat, T. AU - Schwinzerl, M. AU - Sjobak, K.N. AU - Zacharov, I. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - SixTrack Version 5: Status and New Developments J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - SixTrack Version 5 is a major SixTrack release that introduces new features, with improved integration of the existing ones, and extensive code restructuring. New features include dynamic-memory management, scattering-routine integration, a new initial-condition module, and reviewed post-processing methods. Existing features like on-line aperture checking and Fluka-coupling are now enabled by default. Extensive performance regression tests have been developed and deployed as part of the new-release generation. The new features of the tracking environment developed for the massive numerical simulations will be discussed as well. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3200 EP - 3203 KW - simulation KW - electron KW - scattering KW - collimation KW - HOM DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS043 UR - http://jacow.org/ipac2019/papers/wepts043.pdf ER - TY - CONF AU - Furuseth, S.V. AU - Amorim, D. AU - Antipov, S.A. AU - Buffat, X. AU - Mounet, N. AU - Métral, E. AU - Pieloni, T. AU - Salvant, B. AU - Tambasco, C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Instability Latency in the LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Large Hadron Collider (LHC) has experienced multiple instabilities that occur between minutes and hours after the last modification of the machine settings. The existence of instabilities with high latency has been reproduced also in simulations. Dedicated experiments, injecting a controlled noise into the beam, have now been performed to discover the dependence of this latency on key parameters. The results seem compatible with a mechanism linked to a steady and slow modification of the transverse beam distribution leading to a loss of Landau damping. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3204 EP - 3207 KW - octupole KW - experiment KW - feedback KW - damping KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS044 UR - http://jacow.org/ipac2019/papers/wepts044.pdf ER - TY - CONF AU - Furuseth, S.V. AU - Buffat, X. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - High-Performance Scheduling of Multi-Beam Multi-Bunch Simulations J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Coherent multi-bunch interactions through beam-beam forces or wake fields can cause severe impacts on the beams in circular colliders, if not well understood and countered for. COMBI is a parallel multiparticle tracking code developed to study such interactions. Its implementation greatly limits its efficiency when considering realistic configurations featuring effects with different computational requirements, such as the multi-bunch interaction through wake fields, beam-beam interactions, transverse feedback and lattice non-linearities. A new parallel scheduling method, pipelining the effects for each bunch, has greatly sped up the code. The new version of the code, COMBIp, is presented here. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3208 EP - 3211 KW - simulation KW - wakefield KW - collider KW - site KW - hadron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS045 UR - http://jacow.org/ipac2019/papers/wepts045.pdf ER - TY - CONF AU - Papadopoulou, S. AU - Antoniou, F. AU - Efthymiopoulos, I. AU - Hostettler, M. AU - Iadarola, G. AU - Karastathis, N. AU - Kostoglou, S. AU - Papaphilippou, Y. AU - Trad, G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Monitoring and Modelling of the LHC Emittance and Luminosity Evolution in 2018 J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Operating at 6.5 TeV, the LHC surpassed the expectations and delivered an average of 66 fb−1 integrated luminosity to the two high luminosity experiments ATLAS and CMS by the end of 2018. In order to provide a continuous feedback to the machine coordination for further optimizing the performance, an automated tool for monitoring the main beam parameters and machine configurations, has been devised and extensively used. New features like the coupling between the two planes and effects of noise, were added to the numerical model used since 2016 to calculate the machine luminosity. Estimates, based both on simulations and on observed beam parameters, were reported fill-by-fill as well as in overall trends during the year. Highlights of the observations including the observed additional emittance blow up (on top of IBS, SR and elastic scattering) as well as additional losses (on top of the expected proton burn off) are presented for the 2018 data. Finally, cumulated integrated luminosity projections from the model for the entire 2018 data based on different degradation mechanisms are compared also with respect to the achieved luminosity. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3212 EP - 3215 KW - emittance KW - luminosity KW - operation KW - experiment KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS046 UR - http://jacow.org/ipac2019/papers/wepts046.pdf ER - TY - CONF AU - Asvesta, F. AU - Bartosik, H. AU - Huschauer, A. AU - Papaphilippou, Y. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Space Charge Driven Resonances in the CERN PS J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the CERN Proton Synchrotron space charge driven resonances are excited around the operational working point due to the periodicity of the optics functions. In this paper, the resonances are studied using analytical methods, i.e. the evaluation of the resonance driving terms connected to the space charge potential of Gaussian distributions. Furthermore, the resonances are characterized in measurements and simulations for various beams. The beams considered are different in terms of brightness, in order to study the dependence of the resonance strength on the space charge force. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3216 EP - 3219 KW - resonance KW - space-charge KW - brightness KW - simulation KW - lattice DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS047 UR - http://jacow.org/ipac2019/papers/wepts047.pdf ER - TY - CONF AU - Sadovich, S. AU - Rossi, A. AU - Stancari, G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Electron Beam Dynamics Simulation for Electron Lenses J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A test stand is under construction at CERN to study high perveance electron guns, electron beam dynamics, and electron beam diagnostics for electron lenses. It will be used to test electron guns for the Hollow Electron Lenses under consideration for beam halo control for High Luminosity LHC (CERN), and for the Space Charge Compensation at SIS18 (GSI) in the frame of the EU funded ARIES project. In order to prepare for this test stand, simulations will be presented and compared with experiments undertaken at the Fermilab (FNAL) electron lens test stand. These were conducted using a hollow electron gun, with the magnetic field configuration and beam current varied to study their effect. The impact of imperfections on the beam dynamics and overall quality of the electron beam will be discussed. A method for comparing experimental data with simulation is also presented to allow bench-marking of the computer models and simulation tools that will later be applied to the analysis of measurements performed at CERN. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3220 EP - 3223 KW - electron KW - gun KW - simulation KW - cathode KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS048 UR - http://jacow.org/ipac2019/papers/wepts048.pdf ER - TY - CONF AU - Schwarz, M. AU - Iliakis, K. AU - Lasheen, A. AU - Papotti, G. AU - Repond, J. AU - Shaposhnikova, E.N. AU - Timko, H. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Flat-Bottom Instabilities in the CERN SPS J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - At beam intensities of 2.6·10¹¹ protons per bunch, required at SPS injection for the High Luminosity LHC beam, longitudinal instabilities can degrade the beam quality delivered by the SPS, the LHC injector at CERN. In this paper, we concentrate on beam instability at flat bottom. The dependence of the instability threshold on longitudinal emittance and LLRF system settings was measured, to help identify the impedance driving this instability. While reducing the longitudinal emittance reduces the losses at injection, it can drive the beam unstable. The LLRF system of the SPS (partially) compensates beam loading, but also affects the instability. The effect of the different LLRF systems (feedback, feedforward, phase loop and longitudinal damper) and fourth harmonic RF system on the instability was investigated. The measurements are compared with simulations performed with the longitudinal tracking code BLonD. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3224 EP - 3227 KW - simulation KW - impedance KW - HOM KW - feedback KW - LLRF DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS049 UR - http://jacow.org/ipac2019/papers/wepts049.pdf ER - TY - CONF AU - Mether, L. AU - Iadarola, G. AU - Poland, K.L. AU - Rumolo, G. AU - Skripka, G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Multi-Species Electron-Ion Simulations and their Application to the LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - During operation in 2017 and 2018, the LHC suffered from recurrent beam aborts associated with beam losses in one of its arc cells in correlation with quickly developing transverse coherent oscillations. The events are thought to have been caused by a localised high gas density resulting from the phase transition of a macro-particle that has entered the beam. In order to model the observed coherent effects through the interaction of the beam with the induced pressure bump, novel modelling capabilities have been implemented that allow for the simulation of multiple clouds of different particle species and their interaction with the beam. In this contribution the simulation model and its application are described. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3228 EP - 3231 KW - electron KW - simulation KW - operation KW - beam-losses KW - space-charge DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS050 UR - http://jacow.org/ipac2019/papers/wepts050.pdf ER - TY - CONF AU - Skripka, G. AU - Dijkstal, P. AU - Iadarola, G. AU - Mether, L. AU - Rumolo, G. AU - Wulff, E.G.T. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Comparison of Electron Cloud Build-Up Simulations Against Heat Load Measurements for the LHC Arcs With Different Beam Configurations J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Electron cloud effects are among the main performance limitations for the operation of the Large Hadron Collider (LHC) with 25 ns bunch spacing. A large number of electrons impacting on the beam screens of the cold magnets induces significant heat load, reaching values close to the full cooling capacity available from the cryogenic system. Interestingly, it is observed that parts of the machine that are by design identical show very different heat loads. We used numerical simulations to investigate the possibility that these differences are induced by different surface properties, in particular maximum Secondary Electron Yield (SEY) for the different cryomagnets. Using the PyECLOUD code, the electron cloud build-up was simulated assuming different values of SEY in the LHC cold magnets. Comparing the measured heat loads to the simulation results for the 25 ns beams at 450 GeV we have identified the SEY values that match the observations in these conditions. These SEY values were found to be in good agreement with the heat loads measured with different beam configurations (changing the bunch pattern, the bunch intensity and the beam energy). PB - JACoW Publishing CP - Geneva, Switzerland SP - 3232 EP - 3235 KW - electron KW - simulation KW - operation KW - synchrotron-radiation KW - radiation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS051 UR - http://jacow.org/ipac2019/papers/wepts051.pdf ER - TY - CONF AU - Skripka, G. AU - Bracco, C. AU - Iadarola, G. AU - Perillo-Marcone, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Electron Cloud Build-Up Simulations in the Two-Beam Common Chamber of the HL-LHC TDIS With Nonuniform Surface Properties J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The segmented injection protection absorber (TDIS) foreseen for the High-Luminosity Large Hadron Collider (HL-LHC) project is designed to protect the machine in case of injection kicker malfunctioning. Since the current LHC injection protection absorber has suffered from vacuum issues possibly induced by electron multipacting, numerical studies were done to estimate the electron flux expected on the internal surfaces of the TDIS. This device will consist of three pairs of movable absorbing blocks above and below one beam and a beam screen surrounding the second circulating beam. The build-up of electron cloud in the TDIS was simulated accounting for the presence of two counter-rotating beams, for the configuration of the jaws and for the different materials used for the different surfaces in the device. The simulation studies have also investigated the possibility of coating the most critical surfaces with amorphous carbon in order to mitigate the multipacting. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3236 EP - 3239 KW - electron KW - simulation KW - injection KW - vacuum KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS052 UR - http://jacow.org/ipac2019/papers/wepts052.pdf ER - TY - CONF AU - Nissen, E.A. AU - Schulte, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - An Analytic Approach to Emittance Growth from the Beam-Beam Effect with Applications to the LHeC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In colliders with asymmetric rigidity such as the proposed Large Hadron electron Collider, jitter in the weaker beam can cause emittance growth via coherent beam-beam interactions. The LHeC in this case would collide 7 TeV protons on 60 GeV electrons, which can be modeled using a weak-strong model. In this work we estimate the proton beam emittance growth by separating out the longitudinal angular kicks from an off-center bunch interaction and produce an analytic expression for the emittance growth per turn in systems like the LHeC. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3307 EP - 3310 KW - proton KW - emittance KW - electron KW - GUI KW - collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS081 UR - http://jacow.org/ipac2019/papers/wepts081.pdf ER - TY - CONF AU - Arominski, D. AU - Latina, A. AU - Sailer, A. AU - Schulte, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Synchrotron Radiation Reflections in the CLIC Beam Delivery System J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Synchrotron radiation (SR) reflection is an important issue for future linear colliders. High fluxes of the SR might impact the performance of the detector, through irradiation of the forward luminosity and beam quality calorimeters or of the innermost layers of the vertex detector. The photon reflections depend on the beam pipe apertures’ size, their shape, and materials used with various surface roughness. In this work, we present a study of SR including reflection for the 380 GeV and 3 TeV beam parameters and optics of the Compact Linear Collider’s Final Focus System. The simulations of the SR reflections using the Synrad+ software are presented and the impact on the detector is discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3363 EP - 3365 KW - photon KW - detector KW - collider KW - synchrotron KW - radiation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS104 UR - http://jacow.org/ipac2019/papers/wepts104.pdf ER - TY - CONF AU - Meddahi, M. AU - Alemany-Fernández, R. AU - Bartosik, H. AU - Bellodi, G. AU - Coupard, J. AU - Damerau, H. AU - Di Giovanni, G.P. AU - Dos Santos Pedrosa, F.B. AU - Funken, A. AU - Goddard, B. AU - Hanke, K. AU - Huschauer, A. AU - Kain, V. AU - Lombardi, A.M. AU - Mikulec, B. AU - Prodon, S. AU - Rumolo, G. AU - Scrivens, R. AU - Shaposhnikova, E.N. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - LHC Injectors Upgrade Project: Towards New Territory Beam Parameters J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The LHC injectors Upgrade (LIU) project aims at increasing the intensity and brightness in the LHC injectors in order to match the challenging requirements of the High-Luminosity LHC (HL-LHC) project, while ensuring high availability and reliable operation of the injectors complex up to the end of the HL-LHC era (ca. 2035). This requires extensive hardware modifications and new beam dynamics solutions in the entire LHC proton and ion injection chains: the new Linac4, the Proton Synchrotron Booster, the Proton Synchrotron the Super Proton Synchrotron together with the ion PS injectors (the Linac3 and the Low Energy Ion Ring). All hardware modifications will be implemented during the 2019-2020 CERN accelerators shutdown. This talk would analyze the various project phases, share the lessons learned, and conclude on the expected beam parameter reach, together with the related risks. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3385 EP - 3390 KW - target KW - proton KW - operation KW - injection KW - extraction DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THXPLM1 UR - http://jacow.org/ipac2019/papers/thxplm1.pdf ER - TY - CONF AU - Velotti, F.M. AU - Addesa, F.M. AU - Afonin, A.G. AU - Bestmann, P. AU - Borg, J.E. AU - Butcher, M.E.J. AU - Calviani, M. AU - Chesnokov, Y.A. AU - Denisov, A.S. AU - Di Castro, M. AU - Donzé, M. AU - Durum, A.A. AU - Esposito, L.S. AU - Fraser, M.A. AU - Galluccio, F. AU - Garattini, M. AU - Gavrikov, Y. AU - Gilardoni, S.S. AU - Goddard, B. AU - Hall, G. AU - Iacoangeli, F. AU - Ivanov, Yu.M. AU - James, T. AU - Kain, V. AU - Koznov, M.A. AU - Lendaro, J. AU - Maisheev, V.A. AU - Malyarenko, L.G. AU - Masi, A. AU - Mirarchi, D. AU - Murtas, F. AU - Pari, M. AU - Pesaresi, M. AU - Prieto, J. AU - Redaelli, S. AU - Rossi, R. AU - Sandomirskiy, Yu.E. AU - Scandale, W. AU - Seidenbinder, R. AU - Serrano Galvez, P. AU - Skorobogatov, V. AU - Stoel, L.S. AU - Yanovich, A.A. AU - Zamantzas, C. AU - Zhovkovska, V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Demonstration of Loss Reduction Using a Thin Bent Crystal to Shadow an Electrostatic Septum During Resonant Slow Extraction J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A proof-of-principle experiment demonstrating the feasibility of using a thin, bent crystal aligned upstream of an extraction septum (ES) to increase the efficiency of the third-integer resonant slow extraction process has been carried out at the CERN Super Proton Synchrotron (SPS). With the primary aim of reducing the beam loss and induced radio-activation of the SPS, the crystal was aligned to both the beam and the septum to reduce by up to 40% the beam intensity impinging the ES and increase the intensity entering the external transfer line. In this contribution, we introduce the concept and the prototype system that was installed in 2018 before reporting in detail on the dedicated program of machine development studies carried out to characterise its performance and demonstrate operational feasibility. The performance reach and compatibility with other loss reduction techniques proposed to further increase the extraction efficiency, such as phase space folding with octupoles, is discussed in view of future high intensity operation. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3399 EP - 3403 KW - extraction KW - operation KW - septum KW - optics KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THXXPLM2 UR - http://jacow.org/ipac2019/papers/thxxplm2.pdf ER - TY - CONF AU - Golm, J. AU - De Gersem, H. AU - Fernandes, M.F. AU - Haider, D.M. AU - Kurian, F. AU - Marsic, N. AU - Müller, W.F.O. AU - Neubert, R. AU - Schmelz, M. AU - Schmidl, F. AU - Schwickert, M. AU - Seidel, P. AU - Sieber, T. AU - Stolz, R. AU - Stöhlker, T. AU - Tan, J. AU - Tympel, V. AU - Welsch, C.P. AU - Zakosarenko, V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Different Versions of Cryogenic Current Comparators with Magnetic Core for Beam Current Measurements J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - For more than 20 years Cryogenic Current Comparators (CCC) are used to measure the current of charged particle beams with low intensity (nA-range). The device was first established at GSI in Darmstadt and was improved over the past two decades by the cooperation of institutes in Jena, GSI and CERN. The improved versions differ in material parameters and electronics to increase the resolution and in dimensions in order to meet the requirements of the respective application. The device allows non-destructive measurements of the charged particle beam current. The azimuthal magnetic field which is generated by the beam current is detected by low temperature Superconducting Quantum Interference Device (SQUID) current sensors. A complex shaped superconductor cooled down to 4.2 K is used as magnetic shielding and a high permeability core serves as flux concentrator. Three versions of the CCC shall be presented in this work: (1) GSI-Pb-CCC which was running at GSI Darmstadt in a transfer line, (2) CERN-Nb-CCC currently installed in the Antiproton Decelerator at CERN and (3) GSI-Nb-CCC-XD which will be operating in the CRYRING at GSI 2019. Noise, signal and drift measurements were performed in the Cryo-Detector Lab at the University of Jena. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3431 EP - 3434 KW - cryogenics KW - shielding KW - pick-up KW - operation KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THYYPLS2 UR - http://jacow.org/ipac2019/papers/thyypls2.pdf ER - TY - CONF AU - Faus-Golfe, A. AU - Bai, B. AU - Delorme, R. AU - Dosanjh, M. AU - Duchesne, P. AU - Favaudon, V. AU - Fouillade, C. AU - Han, Y. AU - Poortmans, P.M. AU - Pouzoulet, F. AU - Prezado, Y. AU - Vallerand, C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Optics Design and Beam Dynamics Simulation for a VHEE Radiobiology Beam Line at PRAE Accelerator J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Platform for Research and Applications with Electrons (PRAE) is a multidisciplinary R&D facility gathering subatomic physics, instrumentation, radiobiology and clinical research around a high-performance electron accelerator with beam energies up to 70 MeV. In this paper we report the complete optics design and performance evaluation of a Very High Energy Electron (VHEE) innovative radiobiology study, in particular by using Grid mini-beam and FLASH methodologies, which could represent a major breakthrough in Radiation Therapy (RT) treatment modality. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3444 EP - 3447 KW - linac KW - gun KW - radiation KW - electron KW - optics DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPMP002 UR - http://jacow.org/ipac2019/papers/thpmp002.pdf ER - TY - CONF AU - Dosanjh, M. AU - Aggarwal, A. AU - Angal-Kalinin, D. AU - Apsimon, R. AU - Boogert, S.T. AU - Burt, G. AU - Coleman, N. AU - Collier, P. AU - Cross, A.W. AU - Konoplev, I.V. AU - McIntosh, P.A. AU - Militsyn, B.L. AU - Pistenmaa, D.A. AU - Sheehy, S.L. AU - Syratchev, I. AU - Wuensch, W. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Collaborative Strategies for Meeting the Global Need for Cancer Radiation Therapy Treatment Systems J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The idea of designing affordable equipment and developing sustainable infrastructures for delivering radiation treatment for patients with cancer in countries that lack resources and expertise stimulated a first International Cancer Expert Corps (ICEC) championed, CERN-hosted workshop in Geneva in November 2016. Which has since been followed by three additional workshops involving the sponsorship and support from UK Science and Technology Facilities Council (STFC). One of the major challenges in meeting this need to deliver radiotherapy in low- and middle-income countries (LMIC) is to design a linear accelerator and associated instrumentation system which can be operated in locations where general infrastructures and qualified human resources are poor or lacking, power outages and water supply fluctuations can occur frequently and where climatic conditions might be harsh and challenging. In parallel it is essential to address education, training and mentoring requirements for current, as well as future novel radiation therapy treatment (RTT) systems. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3526 EP - 3529 KW - linac KW - electron KW - radiation KW - vacuum KW - permanent-magnet DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPMP038 UR - http://jacow.org/ipac2019/papers/thpmp038.pdf ER - TY - CONF AU - Weikum, M.K. AU - Akhter, T. AU - Alesini, D. AU - Alexandrova, A.S. AU - Anania, M.P. AU - Andreev, N.E. AU - Andriyash, I.A. AU - Aschikhin, A. AU - Audet, T. AU - Aßmann, R.W. AU - Bacci, A. AU - Barna, I.F. AU - Beaton, A. AU - Beck, A. AU - Beluze, A. AU - Bernhard, A. AU - Bielawski, S. AU - Bisesto, F.G. AU - Brandi, F. AU - Brinkmann, R. AU - Bründermann, E. AU - Bussmann, M.H. AU - Bussolino, G. AU - Büscher, M. AU - Chancé, A. AU - Chen, M. AU - Chiadroni, E. AU - Cianchi, A. AU - Clarke, J.A. AU - Cole, J. AU - Couprie, M.-E. AU - Croia, M. AU - Cros, B. AU - Crump, P.A. AU - Dattoli, G. AU - De Nicola, S. AU - Del Dotto, A. AU - Delerue, N. AU - Dias, J.M. AU - Dorda, U. AU - Fedele, R. AU - Ferran Pousa, A. AU - Ferrario, M. AU - Filippi, F. AU - Fiore, G. AU - Fonseca, R.A. AU - Galimberti, M. AU - Gallo, A. AU - Ghaith, A. AU - Giove, D. AU - Giribono, A. AU - Gizzi, L.A. AU - Grüner, F.J. AU - Habib, A.F. AU - Haefner, C. AU - Heinemann, T. AU - Hidding, B. AU - Holzer, B.J. AU - Hooker, S.M. AU - Hosokai, T. AU - Huebner, M. AU - Irman, A. AU - Jafarinia, F. AU - Jaroszynski, D.A. AU - Joshi, C. AU - Kaluza, M. AU - Kando, M. AU - Karger, O.S. AU - Karsch, S. AU - Khazanov, E. AU - Khikhlukha, D. AU - Knetsch, A. AU - Kocon, D. AU - Koester, P. AU - Kononenko, O.S. AU - Korn, G. AU - Kostyukov, I. AU - Kruchinin, K.O. AU - Labate, L. AU - Le Blanc, C. AU - Lechner, C. AU - Leemans, W. AU - Lehrach, A. AU - Li, X. AU - Libov, V. AU - Lifschitz, A. AU - Litvinenko, V. AU - Lu, W. AU - Lundh, O. AU - Maier, A.R. AU - Malka, V. AU - Manahan, G.G. AU - Mangles, S.P.D. AU - Marchetti, B. AU - Martinez de la Ossa, A. AU - Martins, J.L. AU - Mason, P.D. AU - Massimo, F. AU - Mathieu, F. AU - Maynard, G. AU - Mazzotta, Z. AU - Molodozhentsev, A.Y. AU - Mostacci, A. AU - Murphy, C.D. AU - Müller, A.-S. AU - Najmudin, Z. AU - Nghiem, P.A.P. AU - Nguyen, F. AU - Niknejadi, P. AU - Osterhoff, J. AU - Oumbarek Espinos, D. AU - Papadopoulos, D.N. AU - Patrizi, B. AU - Pattathil, R. AU - Petrillo, V. AU - Pocsai, M.A. AU - Poder, K. AU - Pompili, R. AU - Pribyl, L. AU - Pugacheva, D. AU - Romeo, S. AU - Rossetti Conti, M. AU - Rossi, A.R. AU - Rossmanith, R. AU - Roussel, E. AU - Sahai, A.A. AU - Sarri, G. AU - Schaper, L. AU - Scherkl, P. AU - Schramm, U. AU - Schroeder, C.B. AU - Scifo, J. AU - Serafini, L. AU - Sheng, Z.M. AU - Siders, C. AU - Silva, L.O. AU - Silva, T. AU - Simon, C. AU - Sinha, U. AU - Specka, A. AU - Streeter, M.J.V. AU - Svystun, E.N. AU - Symes, D. AU - Szwaj, C. AU - Tauscher, G.E. AU - Terzani, D. AU - Thompson, N. AU - Toci, G. AU - Tomassini, P. AU - Torres, R. AU - Ullmann, D. AU - Vaccarezza, C. AU - Vannini, M. AU - Vieira, J.M. AU - Villa, F. AU - Wahlstrom, C.-G. AU - Walczak, R. AU - Walker, P.A. AU - Wang, K. AU - Welsch, C.P. AU - Wiggins, S.M. AU - Wolfenden, J. AU - Xia, G.X. AU - Yabashi, M. AU - Zhu, J. AU - Zigler, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Status of the Horizon 2020 EuPRAXIA Conceptual Design Study J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Horizon 2020 Project EuPRAXIA (European Plasma Research Accelerator with eXcellence In Applications) is producing a conceptual design report for a highly compact and cost-effective European facility with multi-GeV electron beams accelerated using plasmas. EuPRAXIA will be set up as a distributed Open Innovation platform with two construction sites, one with a focus on beam-driven plasma acceleration (PWFA) and another site with a focus on laser-driven plasma acceleration (LWFA). User areas at both sites will provide access to FEL pilot experiments, positron generation and acceleration, compact radiation sources, and test beams for HEP detector development. Support centres in four different countries will complement the pan-European implementation of this infrastructure. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3638 EP - 3642 KW - plasma KW - laser KW - electron KW - acceleration KW - site DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW026 UR - http://jacow.org/ipac2019/papers/thpgw026.pdf ER - TY - CONF AU - Catherall, R. AU - Giles, T.J. AU - Neyens, G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Exploiting the Potential of ISOLDE at CERN (the EPIC Project) J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The ISOLDE Facility at CERN * is the world’s leading facility for the production of radioactive ion beams (RIBs) using the ISOL (Isotope Separation On-Line) method, providing RIBs at energies from 30 keV to 10 MeV/u for a wide variety of experiments. To improve on its capacity to deliver RIBs further from stability, the EPIC project takes full advantage of recent investments by CERN to upgrade the LHC injectors **. In particular, the new Linac4 and the PS Booster upgrade allow expanding the scope of ISOLDE by providing higher radioactive ion beam intensities further from stability. Sharing the proton-beam between two target stations that simultaneously feed the low-energy and high-energy beam lines will more than double the annual available beam time for experiments. To take further advantage of enhanced beam time, CERN and the ISOLDE collaboration also aims to studies installing a storage ring behind the HIE-ISOLDE post-accelerator to allow the storage of cooled exotic ion beams and thus opening up new possibilities in the fields of astrophysics, fundamental symmetry studies, atomic physics and nuclear physics. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3706 EP - 3708 KW - ISOL KW - experiment KW - target KW - storage-ring KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW053 UR - http://jacow.org/ipac2019/papers/thpgw053.pdf ER - TY - CONF AU - Fedosseev, V. AU - Batsch, F. AU - Capelli, C. AU - Chevallay, E. AU - Chritin, N. AU - Döbert, S. AU - Feniet, T. AU - Friebel, F. AU - Gander, P. AU - Granados, E. AU - Gschwendtner, E. AU - Hansen, J. AU - Heßler, C. AU - Hüther, M. AU - Martyanov, M. AU - Moody, J.T. AU - Muggli, P. AU - Panuganti, H. AU - Szczurek, K.A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Generation and Delivery of an Ultraviolet Laser Beam for the RF-Photoinjector of the Awake Electron Beam J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the AWAKE experiment, the electron beam is used to probe the proton-driven wakefield acceleration in a 10 m long rubidium vapor source. Electron bunches are produced using an RF-gun equipped with a Cs2Te photocathode illuminated by an ultraviolet (UV) laser pulse. To generate the UV laser beam a fraction of the infrared (IR) laser beam used for ionization of rubidium is extracted from the laser system, time-compressed to a picosecond scale and frequency tripled using nonlinear crystals. The transport line of the laser beam over the 20 m distance was built using rigid supports for mirrors and air-evacuated tube to prevent any possible beam pointing instabilities due to vibrations and air convection. Construction of the UV beam optical system enables appropriate beam shaping and control of its size and position on the cathode, as well as time delay with respect to the IR pulse, i.e. with respect to the plasma wakefield seeder. In this paper, we present the design of the UV beam line and results of its commissioning regarding IR/UV conversion, beam pointing stability, and means of beam control and monitoring. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3709 EP - 3712 KW - laser KW - electron KW - cathode KW - plasma KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW054 UR - http://jacow.org/ipac2019/papers/thpgw054.pdf ER - TY - CONF AU - Kemppinen, J. AU - Durand, H.M. AU - Herty, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Improving High Precision Cam Mover’s Stiffness J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Pre-alignment is a key challenge of the Compact Linear Collider (CLIC) study. The requirement for CLIC main beam quadrupole (MBQ) alignment is positioning to within 1 µm from target in 5 degrees of freedom (DOF) with ± 3 mm travel. After motion, the position should be kept passively while the system’s fundamental frequency is above 100 Hz. Cam movers are considered for the task. Traditionally they are used for the alignment of heavier magnets with lower accuracy and stiffness requirement. This paper presents a new CLIC prototype cam mover with design emphasis on the fundamental frequency. A finite element method (FEM) model predicts the mode shapes and eigenfrequencies of the system and can be used for further improving the design. Experimental modal analysis (EMA) of the prototype shows that the prototype’s fundamental frequency is at 44 Hz. It also validates the FEM model. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3713 EP - 3715 KW - FEM KW - alignment KW - interface KW - experiment KW - collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW055 UR - http://jacow.org/ipac2019/papers/thpgw055.pdf ER - TY - CONF AU - Herty, A. AU - De Maria, R. AU - Fessia, P. AU - Gamba, D. AU - Giovannozzi, M. AU - Hansen, J. AU - Lamas Garcia, I. AU - Mainaud Durand, H. AU - Redaelli, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - HL-LHC Full Remote Alignment Study J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - This study explores the benefits of extending the monitoring and remote alignment concept, proposed in the HL-LHC baseline, to additional components of the matching sections of the HL-LHC. The objective was to evaluate the benefits in terms of equipment performance and new opportunities for system simplification. In collaboration with the HL-LHC Working Group on Alignment, critical input parameters such as ground motion, manufacturing, assembly, and alignment tolerances, have been quantified. Solutions for the selected, manually aligned compo-nents have been investigated with the particular focus on vacuum design, mechanical design and the new alignment concept compatible with reliability and maintainability requirements. In this context, collimators and masks are key elements to be included in the extended alignment system. Their supporting systems will integrate the concept of on-line monitoring sensors and an actuator based, remote alignment platform. The full remote alignment of components will provide a positive impact to the machine operation reducing the need of human intervention in the tunnel and providing enhanced flexibility to perform the required alignment adjustment as part of an operational tool for the HL-LHC. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3716 EP - 3719 KW - alignment KW - operation KW - vacuum KW - MMI KW - luminosity DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW057 UR - http://jacow.org/ipac2019/papers/thpgw057.pdf ER - TY - CONF AU - Sosin, M. AU - Blaszczyk, T. AU - Herty, A. AU - Jaros, J. AU - Mainaud Durand, H. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Design and Study of a 6 Degree-Of-Freedom Universal Adjustment Platform for HL-LHC Components J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the accelerator domain, the safe and easy alignment of components located in radioactive areas, is a main concern. The position of devices, such as magnets and collimators, has to be adjusted in a fast and ergonomic way to decrease the ionizing dose received by the personnel. Each equipment type has its own unique set of requirements such as the weight, or the desired position accuracy. The two opposite approaches are, on one hand, a simple and time-consuming manual adjustment, using regulating screws and shims, and, on the other hand, the use of precise and expensive automatic positioning stages and platforms. In the frame of the High Luminosity LHC project, in order to fulfill the safety and technical requirements of alignment for lightweight components, a standardized system is under development. It will provide easy, low-cost and fast adjustment capability for several types of components that could be embarked on it. This paper describes the design, the study and the test results of such a universal adjustment solution. The engineering approach, the lessons learned, the issues and the mechanical components behavior are presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3720 EP - 3722 KW - alignment KW - radiation KW - operation KW - ECR KW - target DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW058 UR - http://jacow.org/ipac2019/papers/thpgw058.pdf ER - TY - CONF AU - Van Dijk, M.W.U. AU - Banerjee, D. AU - Bernhard, J. AU - Brugger, M. AU - Charitonidis, N. AU - D'Alessandro, G. AU - Doble, N. AU - Gatignon, L. AU - Gerbershagen, A. AU - Montbarbon, E. AU - Moulson, M. AU - Rae, B. AU - Rosenthal, M.S. AU - Veit, B. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The K12 Beamline for the KLEVER Experiment J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The KLEVER experiment is proposed to run in the CERN ECN3 underground cavern from 2026 onward. The goal of the experiment is to measure BR(KL -> pi0 nu nu), which could yield information about potential new physics, by itself and in combination with the measurement of BR(K+ -> pi+ nu nu) of NA62. A full description will be given of the considerations in designing the new K12 beamline for KLEVER, as obtained from a purpose made simulation with FLUKA. The high intensities required by KLEVER, 2·10¹³ protons on target every 16.8s, with 5·10¹⁹ protons accumulated over 5~years, place stringent demands on adequate muon sweeping to minimize backgrounds in the detector. The target and primary dump need to be able to survive these demanding conditions, while respecting strict radiation protection criteria. A series of design choices will be shown to lead to a neutral beamline sufficiently capable of suppressing relevant backgrounds, such as photons generated by pi0 decays in the target, and Lambda -> npi0 decays, which mimic the signal decay. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3726 EP - 3729 KW - target KW - photon KW - detector KW - experiment KW - background DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW061 UR - http://jacow.org/ipac2019/papers/thpgw061.pdf ER - TY - CONF AU - Montbarbon, E. AU - Banerjee, D. AU - Bernhard, J. AU - Brethoux, D. AU - Brugger, M. AU - Carlsen, B.D. AU - Charitonidis, N. AU - Ebn Rahmoun, A. AU - Evrard, S. AU - Gatignon, L. AU - Gerbershagen, A. AU - Harrouch, E. AU - Lazzaroni, M. AU - Rae, B. AU - Rosenthal, M.S. AU - Van Dijk, M.W.U. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The New CERN East Area Primary and Secondary Beams J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The East Area is one of the intensely used facilities at CERN, now serving for over 56 years beams to more than 20 user teams and experiments for about 200 days of running each year. Besides primary proton and ion beams for the irradiation facilities IRRAD and CHARM, mixed secondary beams of hadrons, electrons and muons within a range of 0.5 GeV/c to 12 GeV/c are provided. The CERN management approved an upgrade and renovation of the full facility to meet reliably future beam test and physics requirements. We present new, flexible beam optics that will assure better purity of the secondary beams, even with the new possibility of highly pure electron, hadron or muon beams. The upgrade also includes a pulsed powering scheme with energy recovering power supplies and new laminated magnets that will reduce both power and cooling requirements. The renovation phase started already and first beams in the new facility will be delivered from 2021 on. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3730 EP - 3733 KW - target KW - secondary-beams KW - radiation KW - optics KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW062 UR - http://jacow.org/ipac2019/papers/thpgw062.pdf ER - TY - CONF AU - Banerjee, D. AU - Bernhard, J. AU - Brugger, M. AU - Charitonidis, N. AU - Cholak, S. AU - D'Alessandro, G. AU - Gatignon, L. AU - Gerbershagen, A. AU - Montbarbon, E. AU - Rae, B. AU - Rosenthal, M.S. AU - Van Dijk, M.W.U. AU - Veit, B. AU - de Jesus, V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The "Physics Beyond Colliders" Projects for the CERN M2 Beam J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Physics Beyond Colliders is an exploratory study aimed at exploiting the full scientific potential of CERN’s accelerator complex up to 2040 and its scientific infrastructure through projects complementary to the existing and possible future colliders. Within the Conventional Beam Working Group (CBWG), several pro-jects for the M2 beam line in the CERN North Area were proposed, such as a successor for the COMPASS experiment, a muon programme for NA64 dark sector physics, and the MuonE proposal aiming at investigating the hadronic contribution to the vacuum polarisation. We present integration and beam optics studies for 100-160 GeV/c muon beams as well as an outlook for improvements on hadron beams, which include RF-separated options and low-energy antiproton beams and radiation studies for high intensity beams. In addition, necessary beam instrumentation upgrades for beam particle identification and momentum measurements are discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3734 EP - 3737 KW - experiment KW - radiation KW - optics KW - hadron KW - detector DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW063 UR - http://jacow.org/ipac2019/papers/thpgw063.pdf ER - TY - CONF AU - Rosenthal, M.S. AU - Booth, A.C. AU - Charitonidis, N. AU - Chatzidaki, Y. AU - Karyotakis, Y. AU - Nowak, E.M. AU - Ortega Ruiz, I. AU - Sala, P.R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Commissioning Results of the Tertiary Beam Lines for the CERN Neutrino Platform Project J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - For many decades the CERN North Area facility at the Super Proton Synchrotron (SPS) has delivered secondary beams to various fixed target experiments and test beams. In 2018, two new tertiary extensions of the existing beam lines, designated "H2-VLE" and "H4-VLE", have been constructed and successfully commissioned. These beam lines have been designed to provide charged particles of both polarities in the momentum range from 0.3 GeV/c to 12 GeV/c. During the design phase, multiple simulation tools and techniques have been employed to optimize the tertiary beam line layout in terms of particle production, transverse beam dynamics and particle identification on an event-by-event basis. In this paper, a comparison of the simulated performance and the first measurement results obtained during the commissioning phase are presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3738 EP - 3741 KW - MMI KW - target KW - experiment KW - positron KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW064 UR - http://jacow.org/ipac2019/papers/thpgw064.pdf ER - TY - CONF AU - D'Alessandro, G. AU - Bernhard, J. AU - Boogert, S.T. AU - Gerbershagen, A. AU - Gibson, S.M. AU - Nevay, L.J. AU - Rosenthal, M.S. AU - Shields, W. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Implementation of CERN Secondary Beam Lines T9 and T10 in BDSIM J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - CERN has a unique set of secondary beam lines, which deliver particle beams extracted from the PS and SPS accelerators after their interaction with a target, reaching energies up to 400 GeV. These beam lines provide a crucial contribution for test beam facilities and host several fixed target experiments. A correct operation of the beam lines requires precise simulations of the beam optics and studies on the beam-matter interaction, radiation protection, beam equipment survival etc. BDSIM combines tracking studies with energy deposition and beam-matter interaction simulations within one software framework. This paper presents studies conducted on secondary beams with BDSIM for the beam lines T9 and T10. We report the tracking analysis and the energy deposition along the beam line. Tracking analysis validation is demonstrated via comparison to existing code. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3746 EP - 3748 KW - target KW - optics KW - secondary-beams KW - simulation KW - software DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW069 UR - http://jacow.org/ipac2019/papers/thpgw069.pdf ER - TY - CONF AU - Matli, E. AU - Bidault, N. AU - Piselli, E. AU - Rodriguez, J.A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Phasing of Superconductive Cavities of the REX/HIE-ISOLDE LINAC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - ISOLDE is a facility dedicated to the production of a large variety of Radioactive Ion Beams. The facility is located at the European Organization for Nuclear Research (CERN). In addition to two target stations followed by low energy separators, the facility includes a post-accelerating linac with both normal conducting (REX) and superconducting (HIE-ISOLDE) sections. The HIE-ISOLDE section consists of four cryomodules with five SRF cavities each that need to be phased individually. In this paper, we will describe the procedure and the software applications developed to phase each of the cavities as well as improvements that will be introduced in the near future to reduce the time it takes to complete the process. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3786 EP - 3788 KW - cavity KW - detector KW - linac KW - ISOL KW - dipole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW094 UR - http://jacow.org/ipac2019/papers/thpgw094.pdf ER - TY - CONF AU - Bidault, N. AU - Matli, E. AU - Rodriguez, J.A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Characterization of REX/HIE-ISOLDE RFQ Longitudinal Acceptance and Transmission J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Isotope mass Separator On-Line DEvice (ISOLDE) based at CERN, is a Radioactive Ion Beam (RIB) facility where rare isotopes are produced from 1.4 GeV-proton collisions onto a target then are manipulated and transported to user experimental stations for studies, notably in the domain of nuclear physics. The RIB of interest is delivered to a dedicated experimental station either at low (up to 60 keV) or high energy (MeV/u range) after acceleration through the recently completed REX/HIE-ISOLDE linac upgrade. The first stage of the linac consists of normal-conducting IH and spiral-resonators and is preceded by a Radio-Frequency Quadrupole (RFQ). A description of the experimental setup and the specifications of the RFQ will serve as an introduction for the presentation of recent results about the transmission efficiency of the RFQ. Furthermore, a newly developed technique will be demonstrated, that allow the capture of ion beam intensities below the femto-Ampere range. In fine, a measurement of the longitudinal acceptance of the RFQ will be included. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3789 EP - 3791 KW - rfq KW - ISOL KW - detector KW - linac KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW095 UR - http://jacow.org/ipac2019/papers/thpgw095.pdf ER - TY - CONF AU - Matli, E. AU - Hesselberg, T. AU - Nielsen, J.N. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - CERN Accelerator Operation’s Planning Manager and Dashboard J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Running CERN complex of accelerators and infrastructure requires the seamless collaboration of many people, such as operators, experts and people-on-call to name only a few. Distributed in teams from different groups, it is important to centralise schedule planning and operational information and make this information readily available. In BE/OP these tasks are handled by two applications to manage shift work as well as piquet and expert services. At the beginning of 2018, a project was started to replace the ageing web piquet application. While collecting requirements we realised a more flexible application was needed to suit a broader set of customers, and to offer a more generic, people- oriented tool. The new planning tool consists of two separate applications: The Planning Manager, which is used to organise work schedules of a teams members, and to keep each group’s planning up-to-date, coherently, and visible to all involved. The Planning Dashboard, which allows any user to create a customised view of the available services they use. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3792 EP - 3794 KW - interface KW - operation KW - framework KW - controls KW - distributed DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW096 UR - http://jacow.org/ipac2019/papers/thpgw096.pdf ER - TY - CONF AU - Zerlauth, M. AU - Antoine, A. AU - Bartmann, W. AU - Bracco, C. AU - Carlier, E. AU - Charifoulline, Z. AU - Denz, R. AU - Goddard, B. AU - Lechner, A. AU - Magnin, N. AU - Martin, C. AU - Mompo, R. AU - Redaelli, S. AU - Romera, I. AU - Salvachua, B. AU - Schmidt, R. AU - Uythoven, J.A. AU - Verweij, A.P. AU - Wenninger, J. AU - Wiesner, C. AU - Wollmann, D. AU - Zamantzas, C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Operational Performance of the Machine Protection Systems of the Large Hadron Collider During Run 2 and Lessons Learnt for the LIU/HL-LHC Era J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Large Hadron Collider (LHC) has successfully completed its second operational run of four years length in December 2018. Operation will be stopped during two years for maintenance and upgrades. To allow for the successful completion of the diverse physics program at 6.5 TeV, the LHC has been routinely operating with stored beam energies close to 300 MJ per beam during high intensity proton runs as well as being frequently reconfigured to allow for special physic runs and important machine developments. No significant damage has incurred to the protected accelerator equipment throughout the run thanks to the excellent performance of the various machine protection systems, however a number of important observations and new failure scenarios have been identified, which were studied experimentally as well as through detailed simulations. In this contribution, we provide an overview of the performance of the machine protection systems throughout Run 2 as well as the important lessons learnt that will impact consolidation actions and the upgrade of the machine protection systems for the LIU/HL-LHC era. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3875 EP - 3878 KW - operation KW - machine-protect KW - injection KW - optics KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB031 UR - http://jacow.org/ipac2019/papers/thprb031.pdf ER - TY - CONF AU - Albright, S.C.P. AU - Kuczynski, M.D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Beam Based Measurements of Relative RF Phase J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The ferrite loaded RF cavities of the CERN Proton Synchrotron Booster will be replaced with FinemetTM loaded cavities during Long Shutdown 2 2019-2020). To fully realise the potential of the new cavities, the relative RF phases must be aligned along the acceleration ramp, where the revolution frequency changes by nearly a factor of 2. A beam based method of measuring the relative phase between the cavities is desired to give the best possible compensation for the frequency dependent phase shift. In this paper we present an operationally viable method to measure the phase shift as a function of RF frequency. The relative phase of the RF cavities can be aligned to within a few degrees, giving an error on the voltage seen by the beam of less than 1%. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3950 EP - 3953 KW - cavity KW - alignment KW - acceleration KW - booster KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB066 UR - http://jacow.org/ipac2019/papers/thprb066.pdf ER - TY - CONF AU - Albright, S.C.P. AU - Quartullo, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Time Varying RF Phase Noise for Longitudinal Emittance Blow-Up J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - RF phase noise was shown to be effective for controlled longitudinal emittance blow-up in the Proton Synchrotron Booster (PSB) at CERN during beam tests in 2017, with further developments in 2018. At CERN, RF phase noise is used operationally in the Super Proton Synchrotron (SPS) and Large Hadron Collider (LHC). In this paper we show that it is suitable for operation with a variety of beam types in the PSB. In the PSB the synchrotron frequency changes by approximately a factor 4 during the 500 ms acceleration ramp, requiring large changes in the frequency band of the noise. During 2018, a new method of calculating the noise parameters has been demonstrated, which gives upper and lower bounds to the noise frequency band that are smoothly varying through the ramp. The new calculation method has been applied to operational beams accelerated in both single and double RF harmonics, the final results are presented here. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3954 EP - 3957 KW - synchrotron KW - emittance KW - operation KW - proton KW - extraction DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB067 UR - http://jacow.org/ipac2019/papers/thprb067.pdf ER - TY - CONF AU - Angoletta, M.E. AU - Albright, S.C.P. AU - Findlay, A. AU - Jaussi, M. AU - Molendijk, J.C. AU - Pittet, N. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Upgrade of CERN’s PSB Digital Low-Level RF System J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The CERN PS Booster (PSB) is the first circular accelerator in the LHC proton injector chain. The upgrade of this four-ring machine is underway within the framework of the LHC Injectors Upgrade project. The existing digital Low-Level RF (LLRF) system will also be upgraded. This paper outlines the LLRF capabilities required, their implementation and the challenges involved. Results of tests carried out to prepare for the LLRF upgrade are given. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3958 EP - 3961 KW - HLRF KW - LLRF KW - controls KW - operation KW - proton DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB068 UR - http://jacow.org/ipac2019/papers/thprb068.pdf ER - TY - CONF AU - Angoletta, M.E. AU - Jaussi, M. AU - Molendijk, J.C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The New Digital Low-Level RF System for CERN’s Extra Low Energy Antiproton Machine J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - CERN’s new Extra Low ENergy Antiproton accelerator/decelerator (ELENA) completed its initial commissioning in 2018. This machine is equipped with a new digital Low-Level RF (LLRF) system that implements beam and cavity loops as well as longitudinal diagnostics. ELENA’s LLRF was instrumental for machine commissioning by decelerating some 1 E7 antiprotons from 5.3 MeV to 100 keV. Commissioning with H⁻ ions took also place. Challenges faced included coping with low beam intensity and the wide frequency swing. This paper gives an overview of the LLRF system capabilities and operation. Beam results achieved with both H⁻ ions and antiprotons are also shown. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3962 EP - 3965 KW - LLRF KW - proton KW - extraction KW - antiproton KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB069 UR - http://jacow.org/ipac2019/papers/thprb069.pdf ER - TY - CONF AU - Angoletta, M.E. AU - Albright, S.C.P. AU - Findlay, A. AU - Jaussi, M. AU - Molendijk, J.C. AU - Myklebust, V.R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - A New Digital Low-Level RF and Longitudinal Diagnostic System for CERN’s AD J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Antiproton Decelerator (AD) has been routinely providing 3 E7 antiprotons since July 2000 at 100 MeV/c from 3.5 GeV/c. It will be refurbished during the Long Shutdown 2 (LS2) to provide reliable operation for the new Extra Low ENergy Antiproton (ELENA) ring. AD will be equipped with a new digital Low-Level RF (LLRF) system before its restart in 2021. Diagnostics to measure beam intensity, Δp/p and Schottky spectra will also be developed. This paper is an overview of the planned capabilities and implementations, as well as of the challenges to overcome. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3966 EP - 3969 KW - LLRF KW - proton KW - diagnostics KW - antiproton KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB070 UR - http://jacow.org/ipac2019/papers/thprb070.pdf ER - TY - CONF AU - Holma, J. AU - Barnes, M.J. AU - Carlà, M. AU - Catalán Lasheras, N. AU - Iriso, U. AU - Martí, Z. AU - Papaphilippou, Y. AU - Pont, M. AU - Pérez, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Beam-Based Measurements on Two ±12.5 kV Inductive Adders, together with Striplines, for CLIC Damping Ring Extraction Kickers J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The CLIC study is investigating the technical feasibil-ity of an electron-positron linear collider with high lumi-nosity and a nominal centre-of-mass energy of 3 TeV. Pre-damping rings and damping rings (DRs) will produce ultra-low emittance beam with high bunch charge. The DR kicker systems, each of which consists of a set of striplines and two inductive adders, must provide ex-tremely stable field pulses. The DR extraction kicker system is the most demanding: specifications require a field uniformity within ±0.01% and pulses up to 900 ns flattop duration, at ±12.5 kV and 309 A, with ripple and droop of not more than ±0.02 % (±2.5 V), with respect to a reference waveform. Two prototype inductive adders have been designed and built at CERN, and have been tested with prototype striplines installed in the storage ring of the ALBA Synchrotron Light Source, in Spain. The stability of the kicker system, including the modulators, has been evaluated from the beam-based measure-ments and is reported in this paper. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3970 EP - 3973 KW - kicker KW - flattop KW - extraction KW - damping KW - storage-ring DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB071 UR - http://jacow.org/ipac2019/papers/thprb071.pdf ER - TY - CONF AU - Barnes, M.J. AU - Bracco, C. AU - Bregliozzi, G. AU - Chmielinska, A. AU - Ducimetière, L. AU - Goddard, B. AU - Iadarola, G. AU - Kramer, T. AU - Vega Cid, L. AU - Vlachodimitropoulos, V. AU - Weterings, W.J.M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Operational Experience of a Prototype LHC Injection Kicker Magnet with a Low SEY Coating and Redistributed Power Deposition J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the event that it is necessary to exchange an LHC injection kicker magnet (MKI), the newly installed kicker magnet would limit HL-LHC operation for a few hundred hours due to dynamic vacuum activity. A surface coating with a low secondary electron yield, applied to the inner surface of an alumina tube to reduce dynamic vacuum activity without increasing the probability of UFOs, and which is compatible with the high voltage environment, was included in a prototype MKI installed in the LHC during the 2017-18 Year End Technical Stop. In addition, this MKI included an upgrade to relocate a significant portion of beam induced power from the yoke to a ’damping element’: this element is not at pulsed high voltage. The effectiveness of the upgrades has been demonstrated during LHC operation, hence a future version will include water cooling of this ’damping element’. This paper reviews dynamic vacuum around the MKIs and summarizes operational experience of the upgraded MKI. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3974 EP - 3977 KW - kicker KW - injection KW - operation KW - vacuum KW - electron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB072 UR - http://jacow.org/ipac2019/papers/thprb072.pdf ER - TY - CONF AU - Holma, J. AU - Barnes, M.J. AU - Chmielinska, A. AU - Pont, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Laboratory Measurements on Two ±12.5 kV Inductive Adders with ±0.02% Waveform Stability for CLIC Damping Ring Extraction Kickers J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The CLIC study is investigating the technical feasibil-ity of an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. Pre-damping rings and damping rings (DRs) will produce ultra-low emittance beam with high bunch charge. The DR kicker systems must provide extremely stable field pulses to avoid beam emittance increase. Each DR extrac-tion kicker system consists of a set of striplines and two pulse modulators. Specifications for this system require that the modulator produce pulses of 900 ns flattop dura-tion, ±12.5 kV and 305 A, with ripple and droop of not more than ±0.02 % (±2.5 V) with respect to a reference waveform. Inductive adder topology has been chosen for the pulse modulators. Two full-scale, 20-layer, 12.5 kV prototype inductive adders have been designed, built and tested at CERN. This paper presents the measurements of the stability of these adders for two different waveforms: a flat-top waveform and a controlled decay waveform, the latter of which is required to generate flat-top total field for the CLIC DR extraction stripline kicker. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3978 EP - 3981 KW - kicker KW - flattop KW - extraction KW - damping KW - collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB073 UR - http://jacow.org/ipac2019/papers/thprb073.pdf ER - TY - CONF AU - Vlachodimitropoulos, V. AU - Barnes, M.J. AU - Chmielinska, A. AU - Ducimetière, L. AU - Vega Cid, L. AU - Weterings, W.J.M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Studies Towards the New Beam Screen System of the LHC Injection Kicker Magnet for HL-LHC Operation J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Although no heating issues were observed in the Large Hadron Collider’s (LHC) injection kicker magnets (MKIs) during Run 2, simulations suggest that for operation with the high intensity beams of the High Luminosity LHC (HL-LHC) project, the magnet’s ferrite yokes will reach their Curie temperature, thus leading to long turnaround times before a new beam can be safely injected into the machine. To safely enter the HL-LHC era, a campaign to redesign the kicker’s beam screen was launched. An improved beam-screen has already been implemented in an upgraded MKI, that was installed in the LHC tunnel in the Year End Technical Stop (YETS) 17/18, and has been successfully tested during 2018 operation. However, the improved design alone is not expected to be enough for HL-LHC operation, and further modifications are required. In this work, the approach to the design from an electromagnetic point of view is presented and different considered options are reported, emphasising the final design of the new beam screen system that is currently being implemented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3982 EP - 3985 KW - kicker KW - injection KW - operation KW - vacuum KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB074 UR - http://jacow.org/ipac2019/papers/thprb074.pdf ER - TY - CONF AU - Vlachodimitropoulos, V. AU - Barnes, M.J. AU - Chmielinska, A. AU - Ducimetière, L. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Transverse Impedance Measurements and Simulations of the LHC Injection Kicker Magnet J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Kicker magnets contribute significantly to the total impedance budget of many accelerators. Of particular interest, from a beam stability point of view, is the transverse beam coupling impedance (TBCI) that is used to determine intensity limitations of a machine. Until recently, no conclusive TBCI data for the Large Hadron Collider (LHC) injection kicker magnets (MKIs) was available. However, in view of the upgrade of the MKIs for the High-Luminosity LHC (HL-LHC) project, the TBCI of the existing design needed to be estimated to be used as reference for an upgraded version. To that end, electromagnetic simulations were carried out to determine the dipolar and quadrupolar components of the TBCI in the two transverse planes. To validate the simulations, test bench measurements were performed using standard RF measurement techniques. In the present work, the results from TBCI simulations and measurements are reported and compared. Detailed descriptions of the methods and techniques used as well as the realization of the experimental set-up are also given. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3986 EP - 3989 KW - impedance KW - simulation KW - kicker KW - injection KW - coupling DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB075 UR - http://jacow.org/ipac2019/papers/thprb075.pdf ER - TY - CONF AU - Fol, E. AU - Coello de Portugal, J.M. AU - Franchetti, G. AU - Tomás, R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Optics Corrections Using Machine Learning in the LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Optics corrections in the LHC are based on a response matrix approach between available correctors and observables. Supervised learning has been applied to quadrupole error prediction at the LHC giving promising results in simulations and surpassing the performance of the traditional approach. A comparison of different algorithms is given and it is followed by the presentation of further possible concepts to obtain optics corrections using machine learning. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3990 EP - 3993 KW - optics KW - network KW - quadrupole KW - simulation KW - controls DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB077 UR - http://jacow.org/ipac2019/papers/thprb077.pdf ER - TY - CONF AU - Ferrero Colomo, A. AU - Ayala, N. AU - Chmielinska, A. AU - Forte, V. AU - Fraser, M.A. AU - Kramer, T. AU - Sermeus, L. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Performance Validation of the Existing and Upgraded PS Injection Kicker J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The CERN PS injection kicker KFA45 will be upgraded in the framework of the LHC Injector Upgrade (LIU) project to allow for injection of 2 GeV proton beams. This paper summarizes the recent efforts to validate beam based waveform measurements, Pspice simulations and current waveform measurements by direct magnetic field measurements in the aperture of the existing system. The magnetic probe, associated measurement hardware design and measurements results are discussed. The paper concludes with a performance comparison and an outlook to future waveform tuning possibilities. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3994 EP - 3997 KW - kicker KW - injection KW - flattop KW - simulation KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB078 UR - http://jacow.org/ipac2019/papers/thprb078.pdf ER - TY - CONF AU - Stadlbauer, T. AU - Chmielinska, A. AU - Ducimetière, L. AU - Kontelis, D. AU - Kramer, T. AU - Senaj, V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - DC Testing and Phase Resolved Partial Discharge Measurements of the New Trigger Transformers for the LHC Beam Dump Kickers J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - During LS2 the LHC beam dump kicker pulse generators will be subject to a substantial consolidation program. One major part is the replacement of the existing GTO stack trigger transformer by a new more performant one. The transformer is assembled, moulded and tested in-house. Part of the validation procedure are standard DC tests and subsequent discharge monitoring as well as newly introduced phase resolved partial discharge measurements. This paper briefly highlights the trigger transformer parameters and construction and outlines in detail the testing and partial discharge measurements. It concludes with a comparison and analysis of the results of the different measurement techniques. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3998 EP - 4000 KW - high-voltage KW - operation KW - kicker KW - GUI KW - power-supply DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB079 UR - http://jacow.org/ipac2019/papers/thprb079.pdf ER - TY - CONF AU - Hirlaender, S. AU - Fraser, M.A. AU - Goddard, B. AU - Kain, V. AU - Prieto, J. AU - Stoel, L.S. AU - Szakaly, M. AU - Velotti, F.M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Automatisation of the SPS ElectroStatic Septa Alignment J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - An electrostatic septum composed of 5 separate tanks is used to slow-extract the 400 GeV proton beam resonantly on the third integer resonance from the CERN SPS. The septa are all mounted on a single support structure that can move the ensemble coherently and, in addition, the internal anode and cathode of each tank can be moved independently. The septum is aligned to the beam by measuring and minimising the induced beam loss signals in the extraction region following an alignment procedure that is usually carried out manually at the beginning of each year. The large number of positional degrees of freedom complicates the procedure and until recently each tank was aligned one after the other semi-manually, typically requiring 8 hours. It is not uncommon that the septum has to be re-aligned later in the run taking time away from physics programme. To tackle this issue, a simplified beam dynamics and scattering simulation routine was developed to permit error studies with a large number of seeds to be carried out in a reasonable computation time. In this contribution, the simulation model will be described before the results of its exploitation to understand the efficacy of alignment procedures based on different optimization algorithms are discussed and compared to the present operational procedure. The effort culminated with the implementation of an automated alignment procedure based on a Powell optimisation algorithm that reduced the time needed to align the septum by over an order of magnitude. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4001 EP - 4004 KW - alignment KW - simulation KW - extraction KW - operation KW - septum DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB080 UR - http://jacow.org/ipac2019/papers/thprb080.pdf ER - TY - CONF AU - Hagmann, G. AU - Baudrenghien, P. AU - Betz, J.D. AU - Egli, J. AU - Galindo Guarch, F.J. AU - Kotzian, G. AU - Rizzi, M. AU - Schmid, L. AU - Spierer, A. AU - Włostowski, T. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The CERN SPS Low Level RF upgrade Project J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The High Luminosity LHC project (HL-LHC) calls for the doubling of the beam intensity injected from the Super Proton Synchrotron (SPS). This is not possible with the present RF system consisting of four 200 MHz cavities. An upgrade was therefore launched, consisting of the installation of two more cavities during the machine shutdown in 2019-2020 (LS2). Installation of more cavities requires the installation of extra Low Level RF (LLRF) electronics. The present LLRF system consists of the original equipment installed in the 1970s, plus some additions dating from the late 1990s when the SPS was commissioned as LHC injector. The High-Power RF up-grade has motivated a complete renovation of the LLRF during LS2; use of a MicroTCA platform, use of a digital deterministic link for synchronization (the so-called White Rabbit), use of an absolute clock for the processing, new algorithms for reducing the cavity impedance, and a complete re-design of the beam control loops and slip-stacking. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4005 EP - 4008 KW - cavity KW - LLRF KW - controls KW - feedback KW - acceleration DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB082 UR - http://jacow.org/ipac2019/papers/thprb082.pdf ER - TY - CONF AU - Bilko, K. AU - Brugger, M. AU - Garcia Alia, R. AU - Harden, F.J. AU - Kadi, Y. AU - Stein, O. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Detailed Analysis Of The Baseline Dose Levels And Localized Radiation Spikes In The Arc Sections Of The Large Hadron Collider During Run 2 J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Large Hadron Collider (LHC) has eight insertion regions (IRs) which house the large experiments or accelerator equipment. These IRs are interconnected with the arc sections consisting of a periodic magnet structure. During the operation of the LHC small amounts of the beam particles are lost, creating prompt radiation fields in the accelerator tunnels and the adjacent caverns. One of the main loss mechanisms in the LHC arc sections is the interaction of the beam particles with the residual gas molecules. The analysis of the dose levels based on the beam loss measurement data shows that the majority of the measurements have similar levels, which allow to define baseline values for each arc section. The baseline levels decreased during the years 2015, 2016 and stabilised in 2017 and 2018 at annual dose levels below 50 mGy, which can be correlated with the residual gas densities in the LHC arcs. In some location of the arcs radiation spikes exceed the base line by more than two orders of magnitude. In addition to the analysis of these dose levels, a novel approach of identifying local dose maxima and the main driving mechanisms creating these radiation spikes will be presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4009 EP - 4012 KW - radiation KW - operation KW - experiment KW - ECR KW - monitoring DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB083 UR - http://jacow.org/ipac2019/papers/thprb083.pdf ER - TY - CONF AU - Stein, O. AU - Bilko, K. AU - Brugger, M. AU - Garcia Alia, R. AU - Harden, F.J. AU - Kadi, Y. AU - Lechner, A. AU - Lerner, G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Run 2 Prompt Dose Distribution and Evolution at the Large Hadron Collider and Implications for Future Accelerator Operation J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - During the operation of the Large Hadron Collider (LHC) small fractions of beam particles are lost, creating prompt radiation fields in the accelerator tunnels. Exposed electronics and accelerator components show lifetime degradation and stochastic Single Event Effects (SEEs) which can lead to faults and downtime of the LHC. Close to the experiments the radiation levels scale nicely with the integrated luminosity since the luminosity debris is the major contributor for creating the radiation fields in this area of the LHC. In the collimation regions it was expected that the radiation fields scale with the integrated beam intensities since the beams are continuously cleaned from particles which exceed the accelerator’s acceptance. The analysis of radiation data shows that the dose measurements in the collimation regions normalised with the integrated beam intensities for 2016 and 2017 are comparable. Against expectations, the intensity normalised radiation datasets of 2018 in these regions differ significantly from the previous years. Especially in the betatron collimation region the radiation levels are up to a factor 3 higher. The radiation levels in the collimation regions correlate with the levelling of beta-star and the crossing angle in the high luminosity experiments ATLAS and CMS. These increased normalised doses have direct implications on the expected dose levels during future LHC operation, including the High-Luminosity LHC (HL-LHC) upgrade. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4013 EP - 4015 KW - operation KW - radiation KW - collimation KW - proton KW - luminosity DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB084 UR - http://jacow.org/ipac2019/papers/thprb084.pdf ER - TY - CONF AU - Harden, F.J. AU - Bouvard, A. AU - Charitonidis, N. AU - Kadi, Y. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - HiRadMat: A Facility Beyond the Realms of Materials Testing J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The ever-expanding requirements of high-power targets and accelerator equipment has highlighted the need for facilities capable of accommodating experiments with a diverse range of objectives. HiRadMat, a High Radiation to Materials testing facility at CERN has, throughout operation, established itself as a global user facility capable of going beyond its initial design goals. Pulsed high energy, high intensity, proton beams have been delivered to experiments ranging from materials testing, detector’s prototype validation, radiation to electronics assessment and beam instrumentation. A 440 GeV/c proton beam is provided directly from the CERN SPS. Up to 288 bunches/pulse at a maximum pulse intensity of 3.5 x 10¹³ protons/pulse can be delivered. Through collaborative efforts, HiRadMat has developed into a state-of-the-art facility with improved in situ measurement routines, beam diagnostic systems and data acquisition techniques, offered to all users. This contribution summarises the recent experimental achievements, highlights previous facility enhancements and discusses potential future upgrades with particular focus on HiRadMat as a facility open to novel experiments. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4016 EP - 4019 KW - proton KW - experiment KW - radiation KW - target KW - instrumentation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB085 UR - http://jacow.org/ipac2019/papers/thprb085.pdf ER - TY - CONF AU - Vanhoutte, R. AU - Brethoux, D. AU - Ebn Rahmoun, A. AU - Evrard, S. AU - Harden, F.J. AU - Harrouch, E. AU - Lazzaroni, M. AU - Lino Diogo dos Santos, M. AU - Lopez, R. AU - Nogtikov, D.E. AU - Renedo Anglada, J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Design & Optimization of the Alignment Supports for the New Laminated Magnets for the CERN East Area Consolidation Project J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The East Area is one of CERNs experimental area, running since its foundation in 1958. Extracting a 24GeV proton beam from the Proton Synchrotron accelerator, the primary beam is divided into different secondary beams, serving various experiments and user’s facilities such as CLOUD, CHARM, IRRAD. Due to improved optics and an energy saving scheme, the facility will go under a renovation between 2019 and 2020, including the replacement of the magnets with new laminated ones to allow a cycled powering scheme. Those magnets need improved supports, and in some cases even a new design, to optimize the alignment operations in those areas. This article will mainly address the different proposed solutions for plug-in supports as well as for conventional ones. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4020 EP - 4022 KW - alignment KW - radiation KW - operation KW - GUI KW - secondary-beams DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB086 UR - http://jacow.org/ipac2019/papers/thprb086.pdf ER - TY - CONF AU - Lamaille, B.LM. AU - Dragoni, F. AU - Evrard, S. AU - Harden, F.J. AU - Harrouch, E. AU - Lazzaroni, M. AU - Lopez, R. AU - Papastergiou, K.D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Study of the Energy Savings Resulting from the East Area Renovation J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - CERN’s East Experimental Area, situated on the Swiss side of the Meyrin site, with its four beamlines, has served physics for more than 40 years. As the building and equipment are reaching their end of life, a thorough consolidation project has been initiated in order to pro-vide many more years of reliable operation. This article addresses the different proposed solutions to reduce significantly the energy consumption of the East Area. It outlines the methodology applied to estimate as precisely as possible the future attained energy savings, which will result in an estimated reduction of approximately 80% in electricity usage (from 11 GWh to 2 GWh per year) and of approximately 65% in gas usage for heating purpose (from 3 GWh to 1 GWh per year). PB - JACoW Publishing CP - Geneva, Switzerland SP - 4023 EP - 4025 KW - ECR KW - experiment KW - operation KW - power-supply KW - radiation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB087 UR - http://jacow.org/ipac2019/papers/thprb087.pdf ER - TY - CONF AU - Nie, Y.C. AU - Schmidt, R. AU - Uythoven, J.A. AU - Wiesner, C. AU - Wollmann, D. AU - Zerlauth, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Concept of Beam-Related Machine Protection for the Future Circular Collider J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In the Future Circular Collider (FCC) study, a proton-proton circular collider (FCC-hh) is considered with a stored beam energy 20 times higher than that of the LHC. Any uncontrolled release of such energy could potentially result in severe damage to the accelerator components. Machine protection of the FCC-hh is hence very important and challenging. With a machine-protection strategy similar to the LHC, FCC would require up to three turns to dump the beam synchronously after a failure detection. Due to several possible ultrafast failures, which could lead to significant beam losses in a few turns, it is important to further reduce the reaction time of the machine protection system (MPS) for the FCC. Reducing the detection time of a failure by using faster beam monitors, e.g. diamond detectors, can reduce the time between a beam loss and the beam dump request. Communication delay of the interlock system to the beam dumping system can be reduced by using a more direct signal path. More than one beam-free abort gap will shorten the time required for the synchronization between the abort gap and the extraction kicker. Different failure scenarios are classified according to the speed of the failure onset and the subsequent increase of induced beam losses. The critical failure modes, their potential mitigations and impacts on the design of the MPS are presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4085 EP - 4088 KW - machine-protect KW - beam-losses KW - extraction KW - proton KW - collider DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB113 UR - http://jacow.org/ipac2019/papers/thprb113.pdf ER - TY - CONF AU - Schaumann, M. AU - Gamba, D. AU - Guinchard, M. AU - Scislo, L. AU - Wenninger, J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Effect of Ground Motion Introduced by HL-LHC CE Work on LHC Beam Operation J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The official groundbreaking of the civil engineering (CE) work for the high luminosity upgrade of the LHC started on 15 June 2018 parallel to LHC beam operation. Compactor work and shaft excavation around the two low beta experiments, ATLAS and CMS, were expected to induce vibrations to the accelerator magnets and cause orbit disturbance, beam loss and potentially premature beam dumps. Ground motion sensors were installed on the surface and close to the triplets, where the CE works were expected to have the largest impact on the beams. This paper discusses the observations made on the LHC beams that could be correlated to CE work. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4092 EP - 4095 KW - ground-motion KW - luminosity KW - operation KW - civil-engineering KW - GUI DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB116 UR - http://jacow.org/ipac2019/papers/thprb116.pdf ER - TY - CONF AU - Delerue, N. AU - Carduner, H.C. AU - Gerard, R.L. AU - Jenzer, S. AU - Manil, P.M. AU - Repain, P.R. AU - Simar, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Prospects of Additive Manufacturing for Accelerators J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Additive manufacturing allows the production of mechanical components often much faster than traditional manufacturing. Several accelerators components built using additive manufacturing have already been qualified for use in accelerator. A workshop was held in Orsay in December 2018 to discuss the prospects of using additive manufacturing for particle accelerators and particle detectors. We report here on the prospects as far as accelerators are concerned. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4118 EP - 4120 KW - cavity KW - vacuum KW - niobium KW - detector KW - GUI DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPTS008 UR - http://jacow.org/ipac2019/papers/thpts008.pdf ER - TY - CONF AU - Müller, H. AU - Allain, H. AU - Borceto, A. AU - Cho, E.J. AU - Daly, M. AU - Drago, G. AU - Golluccio, G. AU - Grafin, P. AU - Lucas, J. AU - Madur, A. AU - Munoz-Garcia, J.-E. AU - Quettier, L. AU - Reymond, H. AU - Roux, C. AU - Simon, H. AU - Sugita, K. AU - Valesi, G. AU - Van Den Boogaard, L.X. AU - Ventura, D. AU - Winkler, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Design, Production, and Testing of Superconducting Magnets for the Super-FRS J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Super FRS is a two-stage in flight separator to be built next to the site of GSI, Darmstadt, Germany as part of FAIR (Facility for Anti-proton and Ion Research). Its purpose is to create and separate rare isotope beams and to enable the mass measurement also for very short lived nuclei. Due to its three branches a wide variety of experiments can be carried out in frame of the NUSTAR collaboration. Due to the large acceptance needed, the magnets of the Super-FRS have to have a large aperture and therefore only a superconducting solution is feasible. A superferric design with superconducting coils was chosen in which the magnetic field is shaped by an iron yoke. For the dipoles this iron yoke is at warm and only the coils are incorporated in a cryostat. The multiplets, assemblies of quadrupoles and higher order multipole magnets, are completely immersed in a liquid Helium bath. With the exception of special branching dipoles all superconducting magnets of Super-FRS have been contracted and are being built by Elytt in Spain (dipoles) and ASG in Italy (multiplets). The cold test of all magnets will take place in a dedicated test facility at CERN. This contribution will present the status of manufacturing of dipoles and multiplets, and also gives a short overview on the test facility. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4128 EP - 4131 KW - dipole KW - quadrupole KW - cryogenics KW - octupole KW - superconducting-magnet DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPTS011 UR - http://jacow.org/ipac2019/papers/thpts011.pdf ER - TY - CONF AU - Denz, R. AU - Blasco Serrano, D. AU - Calcoen, D.O. AU - De Matteis, E. AU - Froidbise, V. AU - Georgakakis, S. AU - Haas, S. AU - Mundra, S. AU - Podzorny, T. AU - Siemko, A.P. AU - Spasic, J. AU - Steckert, J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Quench Detection and Diagnostic Systems for the Superconducting Circuits for the HL-LHC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The High Luminosity LHC project (HL-LHC) will incorporate a new generation of superconducting elements such as high field superconducting magnets based on Nb₃Sn conductors and MgB₂ based high temperature superconducting links for magnet powering. In addition, the HL-LHC will also feature new generations of NbTi based magnets. The proper protection and diagnostics of those elements require the development of a new generation of integrated quench detection and data acquisition systems as well as novel methods for quench detection. The next generation of quench detection systems is to a large extent software defined and serves at the same time as high performance data acquisition system. The contribution will discuss the specific needs of HL-LHC in terms of quench detection and present recent results from tests with prototype magnets. The contribution will show the implementation of new quench detection methods such as current derivative sensors. Measures for increasing the system dependability and easing its maintenance will be explained, as well as the improved supervision architecture using Ethernet based field-bus systems for fast data transmission. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4183 EP - 4186 KW - dipole KW - luminosity KW - data-acquisition KW - radiation KW - electronics DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPTS036 UR - http://jacow.org/ipac2019/papers/thpts036.pdf ER - TY - CONF AU - Kovalenko, A.D. AU - Bordini, B. AU - Gromov, V.A.. AU - Kolomiets, A. AU - Kozub, S. AU - Perepelkin, E.E. AU - Shirkov, G. AU - Tkachenko, L. AU - Tommasini, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Design of a Fast Cycled Low Loss 6 T Model Dipole Cooling at 1.9 K J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The option being considered for the FCC-hh high energy injector is a superconducting synchrotron replacing the CERN SPS. The new machine would operate in a cycled mode also to feed experimental areas, much like the SPS nowadays. Due to this specific cycled operation, innovative design and development approaches is required to cope with the AC losses in the superconducting cables and iron yoke. The research joins experience accumulated at CERN and JINR respectively in the design and operation of large systems operated at 1.9 K and, in fast ramped and cycled magnets. The specified parameters are the following: magnet aperture -80 mm; aperture field - 6 T; field ramp 0.2-0.5 T/s; coil conductor - NbTi; magnetic field homogeneity between 0.12 and 6 T of the order of 5·10⁻⁴. The minimization of the cycling losses is particular important. Total thermal losses should be limited to tentatively < 2 W/m at 4.2 K. The magnet design, and the results of preliminary tests on a candidate NbTi-wire for building a model magnet are presented and discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4221 EP - 4223 KW - dipole KW - synchrotron KW - experiment KW - superconducting-magnet KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPTS053 UR - http://jacow.org/ipac2019/papers/thpts053.pdf ER - TY - CONF AU - Sanz Ull, A. AU - Atanasov, M.G. AU - Balhan, B. AU - Borburgh, J.C.C.M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Alternative Proposal for FCC-hh Extraction Septa J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Challenging requirements are set for the FCC extraction septa magnets, notably for the magnetic field level, the septum thickness and the leak field. An alternative to the baseline FCC extraction layout with normal conducting Lambertson septa is proposed, consisting of a Superconducting Shield (SuShi) stage and a Truncated Cosine theta septa stage with the aim of reducing the necessary number of septa and installed length. The principal parameters of the septa are described and the feasibility discussed. Areas for study improvement are identified. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4248 EP - 4251 KW - septum KW - extraction KW - quadrupole KW - vacuum KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPTS062 UR - http://jacow.org/ipac2019/papers/thpts062.pdf ER - TY - CONF AU - Teofili, L. AU - Giordano, F. AU - Lamas, I. AU - Marongiu, M. AU - Migliorati, M. AU - Nuiry, F.-X. AU - Romagnoli, G. AU - Salvant, B. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Analysis on the Thermal Response to Beam Impedance Heating of the Post Ls2 Proton Synchrotron Beam Dump J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The High Luminosity Large Hadron Collider (HL-LHC) and the LIU (LHC-Injection Upgrade) projects at CERN are upgrading the whole CERN accelerators chain, increasing beam brightness and intensity. In this scenario, some critical machine components have to be redesigned and rebuilt. Due to the increase in beam intensity, minimizing the electromagnetic interaction between the beam and the device is a crucial design task. Indeed, these interactions could lead to beam instabilities and excessive thermo-mechanical loadings in the device. In this context, this paper presents an example of multi-physics study to investigate the impedance related thermal effects. The analysis is performed on the conceptual design of the new proton synchrotron (PS) internal dump. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4260 EP - 4263 KW - impedance KW - simulation KW - proton KW - site KW - wakefield DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPTS065 UR - http://jacow.org/ipac2019/papers/thpts065.pdf ER - TY - CONF AU - Will, A. AU - Bastian, Y. AU - Bernhard, A. AU - Bonura, M. AU - Bordini, B. AU - Favre, M. AU - Lindstrom, B. AU - Mentink, M. AU - Monteuuis, A. AU - Müller, A.-S. AU - Oslandsbotn, A. AU - Schmidt, R. AU - Senatore, C. AU - Siemko, A.P. AU - Stachon, K. AU - Usoskin, A. AU - Vaananen, M.P. AU - Verweij, A.P. AU - Wollmann, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Beam Impact Experiment of 440GeV/p Protons on Superconducting Wires and Tapes in a Cryogenic Environment J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The superconducting magnets used in high energy particle accelerators such as CERN’s LHC can be impacted by the circulating beam in case of specific failure cases. This leads to interaction of the beam particles with the magnet components, like the superconducting coils, directly or via secondary particle showers. The interaction leads to energy deposition in the timescale of microseconds and induces large thermal gradients within the superconductors in the order of 100 K/mm. To investigate the effect on the superconductors, an experiment at CERN’s HiRadMat facility was designed and executed, exposing short samples of Nb-Ti and Nb₃Sn strands as well as YBCO tape in a cryogenic environment to microsecond 440 GeV/p proton beams. The irradiated samples were extracted and are being analyzed for their superconducting properties, such as the critical transport current. This paper describes the experimental setup as well as the first results of the visual inspection of the samples. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4264 EP - 4267 KW - experiment KW - proton KW - interface KW - simulation KW - cryogenics DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPTS066 UR - http://jacow.org/ipac2019/papers/thpts066.pdf ER - TY - CONF AU - Wollmann, D. AU - Bernhard, A. AU - Cangialosi, C. AU - Cerutti, F. AU - D'Angelo, G. AU - Danzeca, S. AU - Denz, R. AU - Favre, M. AU - Garcia Alia, R. AU - Hagedorn, D. AU - Infantino, A. AU - Kirby, G. AU - Kistrup, L. AU - Koettig, T. AU - Lendaro, J. AU - Lindstrom, B. AU - Monteuuis, A. AU - Müller, A.-S. AU - Rodriguez-Mateos, F. AU - Siemko, A.P. AU - Stachon, K. AU - Tsinganis, A. AU - Valette, M. AU - Verweij, A.P. AU - Will, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Characterisation of the Radiation Hardness of Cryogenic Bypass Diodes for the HL-LHC Inner Triplet Quadrupole Circuit J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The powering layout of the new HL-LHC Nb₃Sn triplet circuits is the use of cryogenic bypass diodes, where the diodes are located inside an extension to the magnet cryostat, operated in superfluid helium and exposed to radiation. Therefore, the radiation hardness of different type of bypass diodes has been tested at low temperatures in CERN’s CHARM irradiation facility during the operational year 2018. The forward characteristics, the turn on voltage and the reverse blocking voltage of each diode were measured weekly at 4.2 K and 77 K, respectively, as a function of the accumulated radiation dose. The diodes were submitted to a dose close to 12 kGy and a 1 MeV equivalent neutron fluence of 2.2x10¹⁴,n/cm². After the end of the irradiation campaign the annealing behaviour of the diodes was tested by increasing the temperature slowly to 300 K. This paper describes the experimental setup, the measurement procedure and discusses the results of the measurements. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4268 EP - 4271 KW - radiation KW - neutron KW - experiment KW - quadrupole KW - luminosity DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPTS067 UR - http://jacow.org/ipac2019/papers/thpts067.pdf ER -