TY - CONF AU - Bettoni, S. AU - Craievich, P. AU - Ferrari, E. AU - Ganter, R. AU - Lutman, A.A. AU - Marcellini, F. AU - Penco, G. AU - Prat, E. AU - Reiche, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Beam Manipulation Using Self-Induced Fields at the SwissFEL 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 the past years wakefield sources have been used to manipulate electron beams in accelerators. We recently installed corrugated structures for a total length of 2~m at the SwissFEL injector to test novel schemes for beam manipulations. We present simulations and early experimental results. We compare the model predictions with the measured data for the bunch energy losses and the kick factor, and show early results for the longitudinal phase space linearization and the production of current spikes. PB - JACoW Publishing CP - Geneva, Switzerland SP - 266 EP - 269 KW - FEL KW - simulation KW - electron KW - experiment KW - wakefield DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW073 UR - http://jacow.org/ipac2019/papers/mopgw073.pdf ER - TY - CONF AU - Lou, W. AU - Gulliford, C.M. AU - Hoffstaetter, G.H. AU - Mayes, C.E. AU - Sagan, D. AU - Tsoupas, N. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Coherent Synchrotron Radiation Simulation for CBETA J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - CBETA is an energy recovery linac accelerating from 6 MeV to 150 MeV in four linac passes, using a single return beamline accepting all energies from 42 to 150 MeV. While CBETA gives promise to deliver unprecedentedly high beam current with simultaneously small emittance, Coherent Synchrotron Radiation (CSR) can pose detrimental effect on the beam at high bunch charges and short bunch lengths. To investigate the CSR effects on CBETA, we used the established simulation code Bmad to track a bunch with different parameters. We found that CSR causes phase space dilution, and the effect becomes more significant as the bunch charge and recirculation pass increase. Potential ways to mitigate the effect involving vacuum chamber shielding and increasing bunch length are being investigated. PB - JACoW Publishing CP - Geneva, Switzerland SP - 406 EP - 409 KW - simulation KW - linac KW - lattice KW - radiation KW - shielding DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW124 UR - http://jacow.org/ipac2019/papers/mopgw124.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 - Lobach, I. AU - Halavanau, A. AU - Huang, Z. AU - Kim, K. AU - Lebedev, V.A. AU - Murokh, A.Y. AU - Nagaitsev, S. AU - Romanov, A.L. AU - Shaftan, T.V. AU - Stancari, G. AU - Valishev, A. AU - Yakimenko, V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Study of Fluctuations in Undulator Radiation in the IOTA Ring at Fermilab J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We study turn-by-turn fluctuations in the number of emitted photons in an undulator, installed in the IOTA electron storage ring at Fermilab with an InGaAs PIN photodiode and an integrating circuit. Our study was motivated by the previous experiment *. We propose a theoretical model for the experimental data from * and in our own experiment we attempted to verify the model in an independent and more systematic way. Moreover, these fluctuations are an interesting subject for a study by itself, since they act as a seed for SASE in FELs. We improve the precision of the measurements from * by subtracting the average signal amplitude using a comb filter with a one-turn IOTA delay, and by using a special algorithm for noise subtraction. We obtain a reasonable agreement between our theoretical model and experiment. Along with repeating the experiment from *, which was performed at a constant beam current, we also collect data for fluctuations in undulator light at different beam current values. Lastly, in our experiment we were able to see the transition from Poisson statistics to Super-Poisson statistics for undulator light, whereas in * only the latter statistics was observed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 777 EP - 780 KW - experiment KW - undulator KW - electron KW - radiation KW - photon DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPRB088 UR - http://jacow.org/ipac2019/papers/moprb088.pdf ER - TY - CONF AU - Stupakov, G. AU - Baxevanis, P. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - 3D Theory of Microbunched Electron Cooling for Electron-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 - The Microbunched Electron Cooling (MBEC) * is a promising cooling technique that can find applications in future hadron and electron-ion colliders. A 1D model of MBEC has been recently developed in Ref. **. This model predicts the cooling time below two hours for eRHIC 255 GeV proton beams, when two amplification sections are used in the cooling system. In this work, we go beyond the 1D model of Ref. * and develop a realistic 3D theory of MBEC. Our approach is based on the analysis of the dynamics of microscopic 3D fluctuations in the electron and hadron beams during their interaction and propagation through the system. We derive an analytical expression for the cooling rate and optimize it for the parameters of eRHIC. Our analytical results are in reasonable agreement with simulations. PB - JACoW Publishing CP - Geneva, Switzerland SP - 814 EP - 817 KW - electron KW - hadron KW - kicker KW - simulation KW - betatron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPRB106 UR - http://jacow.org/ipac2019/papers/moprb106.pdf ER - TY - CONF AU - White, G.R. AU - Cobb, T.M. AU - Dalesio, L.R. AU - Davidsaver, M.A. AU - Hartman, S.M. AU - Hickin, D.G. AU - Johnson, A.N. AU - Junkes, H. AU - Kasemir, K.-U. AU - Konrad, M.G. AU - Korhonen, T. AU - Kraimer, M.R. AU - Lange, R. AU - Pearson, M.R. AU - Rivers, M.L. AU - Sekoranja, M. AU - Shankar, M.V. AU - Shen, G. AU - Shroff, K. AU - Veseli, S. AU - Vodopivec, K. AU - Zimoch, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The EPICS Software Framework Moves from Controls to Physics J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Experimental Physics and Industrial Control System (EPICS), is an open-source software framework for high-performance distributed control, and is at the heart of many of the world’s large accelerators and telescopes. Recently, EPICS has undergone a major revision, with the aim of better computing supporting for the next generation of machines and analytical tools. Many new data types, such as matrices, tables, images, and statistical descriptions, plus users’ own data types, now supplement the simple scalar and waveform types of the former EPICS. New computational architectures for scientific computing have been added for high-performance data processing services and pipelining. Python and Java bindings have enabled powerful new user interfaces. The result has been that controls are now being integrated with modelling and simulation, machine learning, enterprise databases, and experiment DAQs. We introduce this new EPICS (version 7) from the perspective of accelerator physics and review early adoption cases in accelerators around the world. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1216 EP - 1218 KW - EPICS KW - controls KW - detector KW - database KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUZZPLM3 UR - http://jacow.org/ipac2019/papers/tuzzplm3.pdf ER - TY - CONF AU - Stupakov, G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - New Method of Calculation of the Wake due to Radiation and Space Charge Forces in Relativistic Beams J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Radiation reaction force in a relativistic beam, also known as a CSR wakefield, is often computed using a 1D model of a line charge beam. While this model can serve as a useful tool for a quick calculation, in some cases, it may not be sufficiently accurate. In particular, this model misses the so-called compression effects associated with the change of the electromagnetic energy when the beam is compressed longitudinally or transversely. The existing 3D simulation codes that take this effect into account are often slow and are not easy to use. In this work, we propose a new approach to the calculations of radiation and space charge longitudinal forces based on the use of the integrals for the retarded potentials. Our main result expresses the rate of change of particles energy through 2D (in a 2D model) or 3D integrals for a given orbit of the beam. It generalizes the 1D model and includes the transient effects of at the entrance and the exit from the magnet. For a given beam line with known magnetic lattice, and a known distribution function of the beam, the calculation reduces to taking 2D or 3D integrals along the orbit. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1223 EP - 1226 KW - radiation KW - wakefield KW - electron KW - space-charge KW - synchrotron-radiation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUZZPLS3 UR - http://jacow.org/ipac2019/papers/tuzzpls3.pdf ER - TY - CONF AU - Li, C.L. AU - Chao, A. AU - Feng, C. AU - Jiang, B.C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Lattice Design for the Reversible SSMB J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Steady State Microbunching (SSMB) aiming at producing high average power radiation in the electron storage ring has been proposed by Ratner and Chao years ago. Reversible seeding scheme is one of the promising scenarios with less challenges on the storage ring lattice design. The key problem for reversible SSMB is the precise cancelation of the laser modulation which will allow producing turn-by-turn coherent radiation without spoiling the transverse emittances and energy spread. In this paper the lattice design for the microbunching generation and its cancelation will be presented. Also a storage ring lattice design will be shown. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1507 EP - 1509 KW - radiation KW - electron KW - emittance KW - storage-ring KW - bunching DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPGW045 UR - http://jacow.org/ipac2019/papers/tupgw045.pdf ER - TY - CONF AU - Toufexis, F. AU - Angier, B.J. AU - Gamzina, D. AU - Tantawi, S.G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Fabrication & Cold Tests of a Millimeter-Period RF Undulator J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - To reduce the linac energy required for an FEL radiating at a given wavelength, and hence its size, a smaller undulator period with sufficient field strength is needed. Previous work from our group successfully demonstrated a microwave undulator at 11.424GHz, using a corrugated cylindrical waveguide operating at the HE11 modes. We have designed a mm-wave undulator cavity at 91.392GHz* with an equivalent undulator period of 1.75 mm. This undulator requires 1.4 MW for sub microsecond pulses for an equivalent K value of 0.1. In this work we present the mechanical design and fabrication of this 91.392 GHz RF Undulator, as well as preliminary cold test data. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1643 EP - 1646 KW - undulator KW - laser KW - FEL KW - GUI KW - electron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPGW098 UR - http://jacow.org/ipac2019/papers/tupgw098.pdf ER - TY - CONF AU - Toufexis, F. AU - Dolgashev, V.A. AU - Huang, X. AU - Li, Z. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Superconducting Crab Cavity Options for Short X-Ray Pulse Generation in SPEAR3 J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We are exploring methods to generate short X-ray pulses in SPEAR3 on the order of 1 ps to enable studying ultrafast processes in materials. We are developing a 2-frequency crab cavity scheme with two sets of crab cavities* at the 6th and 6.5th harmonics of the 476 MHz ring RF frequency. In previous work we studied a normal conducting crab cavity for SPEAR3**. In this work we explored two superconducting cavity options: a traditional elliptical cavity and the Quasi-waveguide Resonator***. We found that the Quasi-waveguide Resonator cannot meet our field uniformity specifications due to higher order multipole fields. We then optimized a traditional elliptical cavity with the input, Lower Order Modes, and Higher Order Modes couplers following the Argonne Advanced Photon Source design. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1647 EP - 1650 KW - cavity KW - sextupole KW - GUI KW - impedance KW - HOM DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPGW099 UR - http://jacow.org/ipac2019/papers/tupgw099.pdf ER - TY - CONF AU - Michnoff, R.J. AU - Banerjee, N. AU - Barley, J. AU - Bartnik, A.C. AU - Bazarov, I.V. AU - Berg, J.S. AU - Brooks, S.J. AU - Burke, D.C. AU - Cintorino, J. AU - Crittenden, J.A. AU - Cultrera, L. AU - Dobbins, J. AU - Douglas, D. AU - Dunham, M. AU - Full, S.J. AU - Furuta, F. AU - Gallagher, R.E. AU - Ge, M. AU - Gulliford, C.M. AU - Hao, Y. AU - Heltsley, B.K. AU - Hoffstaetter, G.H. AU - Jusic, D. AU - Kaplan, R.P.K. AU - Kostroun, V.O. AU - Li, Y. AU - Liepe, M. AU - Liu, C. AU - Lou, W. AU - Mahler, G.J. AU - Mayes, C.E. AU - Méot, F. AU - Patterson, J.R. AU - Peggs, S. AU - Ptitsyn, V. AU - Quigley, P. AU - Roser, T. AU - Sabol, D.M. AU - Sagan, D. AU - Sears, J. AU - Shore, C.H. AU - Smith, E.N. AU - Smolenski, K.W. AU - Thieberger, P. AU - Trabocchi, S. AU - Trbojevic, D. AU - Tsoupas, N. AU - Tuozzolo, J.E. AU - Veshcherevich, V. AU - Widger, D. AU - Willeke, F.J. AU - Witte, H. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - CBETA - Novel Superconducting ERL J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We are successfully commissioning a unique Cornell University and Brookhaven National Laboratory Electron Recovery Linac (ERL) Test Accelerator ’CBETA’ [1]. The ERL has four accelerating passes through the supercon-ducting linac with a single Fixed Field Alternating Linear Gradient (FFA-LG) return beam line built of the Halbach type permanent magnets. CBETA ERL accelerates elec-trons from 42 MeV to 150 MeV, with the 6 MeV injec-tor. The novelties are that four electron beams, with ener-gies of 42, 78, 114, and 150 MeV, are merged by spreader beam lines into a single arc FFA-LG beam line. The elec-tron beams from the Main Linac Cryomodule (MLC) pass through the FFA-LG arc and are adiabatically merged into a single straight line. From the straight section the beams are brought back to the MLC the same way. This is the first 4 pass superconducting ERL and the first single permanent magnet return line. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1651 EP - 1653 KW - electron KW - linac KW - MMI KW - operation KW - cryomodule DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPGW102 UR - http://jacow.org/ipac2019/papers/tupgw102.pdf ER - TY - CONF AU - Zhou, G. AU - Jiao, Y. AU - Raubenheimer, T.O. AU - Tsai, C.-Y. AU - Wang, J.Q. AU - Wu, J. AU - Yang, C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Coherence Time Characterization for Self-Amplified Spontaneous Emission Free-Electron Lasers 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 challenges in scientific researches based on free-electron lasers (FELs) is the characterization of the coherence time of the ultra-fast hard x-ray pulse, which fundamentally influences the interaction process between x-ray and materials. Conventional optical methods, based on autocorrelation, is very difficult to realize due to the lack of mirrors. Here, we experimentally demonstrate a conceptually new coherence time characterization method and a coherence time of 174.7 attoseonds has been measured for the 6.92 keV FEL pulses at Linac Coherent Light Source. In our experiment, a phase shifter is adopted to control the cross-correlation between x-ray and microbunched electrons. This approach provides critical temporal coherence diagnostics for x-ray FELs, and is decoupled from machine parameters, applicable for any photon energy, radiation brightness, repetition rate and FEL pulse duration, etc. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1820 EP - 1823 KW - electron KW - FEL KW - laser KW - free-electron-laser KW - radiation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB062 UR - http://jacow.org/ipac2019/papers/tuprb062.pdf ER - TY - CONF AU - Decker, F.-J. AU - Colocho, W.S. AU - Glenzer, S.H. AU - Lutman, A.A. AU - Miahnahri, A. AU - Ratner, D.F. AU - Sheppard, J.C. AU - Vetter, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Four X-ray Pulses within 10 ns at LCLS J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The X-Ray FEL at SLAC or LCLS delivers typically one bunch at the time. Different schemes of two bunches have been developed: Two bucket, Twin bunch, split undulator, and fresh slice. Here we discuss a four bunch or even eight bunch setup, separated by 2 RF buckets or 0.7 ns. . The demand comes from MEC (Matter in Extreme Conditions) experiments, where high-power laser beams with Joule-class energies create impulsive pressure waves compressing materials on time scales of the order of ns. Eight snapshots for a single experiment will allow measuring the compression history, structural phase transitions into new high-pressure material states, and have the potential to resolve the transition kinetics time scales. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1859 EP - 1862 KW - laser KW - experiment KW - FEL KW - electron KW - gun DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB086 UR - http://jacow.org/ipac2019/papers/tuprb086.pdf ER - TY - CONF AU - Halavanau, A. AU - Decker, F.-J. AU - Ding, Y. AU - Emma, C. AU - Huang, Z. AU - Krzywiński, J. AU - Lutman, A.A. AU - Marcus, G. AU - Pellegrini, C. AU - Zhu, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Generation of High Peak Power Hard X-Rays at LCLS-II with Double Bunch Self-seeding J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We propose to use existing LCLS copper S-band linac double bunch infrastructure to significantly improve LCLS-II hard X-ray performance. In our setup, we use the first bunch to generate a strong seeding X-ray signal, and the second bunch, initially traveling off-axis, to interact with the seed in the amplifier undulator and generate a near TW, 15 fs duration X-ray pulse in the 4 to 8 keV photon energy range. We investigate, via numerical simulations, the required transverse beam dynamics and the four crystals X-ray monochromator to be added to the existing LCLS-II beamline and discuss the final properties of the hard X-ray pulses and their potential application in high intensity, high-field physics experiments, including QED above the Schwinger critical field. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1863 EP - 1866 KW - FEL KW - electron KW - photon KW - laser KW - undulator DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB088 UR - http://jacow.org/ipac2019/papers/tuprb088.pdf ER - TY - CONF AU - Halavanau, A. AU - Huang, Z. AU - Lobach, I. AU - Nagaitsev, S. AU - Pellegrini, C. AU - Raubenheimer, T.O. AU - Seipt, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Undulator Radiation Generated by a Single Electron J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The facilities providing single electron beams are currently being commissioned at Fermilab and will be at SLAC. Recently, Fermilab’s IOTA ring routinely demonstrated circulation of a single electron at 100 MeV beam energy. Alternatively, SLAC is working on constructing LCLS-II an X-ray FEL driven by a 4 GeV SRF linac. A parasitic beamline, S30XL, is planned that will extract 4 GeV dark current from between the primary LCLS-II electron bunches. The dark current will be delivered to End Station A and can work independently of LCLS-II experiments. The dark current will be bunched at a frequency of 46 MHz while extracted current varied from single electrons to 10’s of nA. In the present paper, we estimate the feasibility of propagating single electron beams through a conventional undulator, placed in the IOTA and S30XL beamlines. We explore the possible observable effects and experimental parameters range. In addition, we focus on potential applications of such beams in systems for high fidelity quantum measurements. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1867 EP - 1870 KW - electron KW - undulator KW - photon KW - experiment KW - radiation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB089 UR - http://jacow.org/ipac2019/papers/tuprb089.pdf ER - TY - CONF AU - Halavanau, A. AU - Benediktovitch, A.I. AU - Pellegrini, C. AU - Rohringer, N. AU - Wu, J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Preliminary Considerations of Atomic Inner-Shell X-Ray Laser for Self-Seeding at LCLS-II J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The atomic inner-shell X-ray lasing, induced by the irradiation of focused XFEL SASE pulses, was demonstrated in gases, liquid jets and solids. In this proceeding, we discuss the possible use of this concept in self-seeding scheme at LCLS-II. We provide a preliminary study of different lasing media and corresponding SASE XFEL parameters. For the case of noble gas inner-shell X-ray laser, we study the requirements for gas pressure and XFEL pulse focusing. Finally, we discuss possible designs of this system and its advantages in LCLS-II operations. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1871 EP - 1874 KW - FEL KW - photon KW - simulation KW - radiation KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB090 UR - http://jacow.org/ipac2019/papers/tuprb090.pdf ER - TY - CONF AU - Emma, C. AU - Guetg, M.W. AU - Halavanau, A. AU - Lutman, A.A. AU - Marcus, G. AU - Maxwell, T.J. AU - Pellegrini, C. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Study of XFEL Third Harmonic Radiation at LCLS 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 focus on characterization of the nonlinear third harmonic radiation properties at Linac Coherent Light Source (LCLS). In addition, we experimentally perform third harmonic self-seeding, using diamond crystal attenuator in the hard X-ray self-seeding chicane. We discuss warm beam effects in such scheme, justifying recently proposed two bunch configuration for harmonic lasing. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1875 EP - 1877 KW - undulator KW - FEL KW - radiation KW - experiment KW - bunching DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB091 UR - http://jacow.org/ipac2019/papers/tuprb091.pdf ER - TY - CONF AU - Halavanau, A. AU - Benediktovitch, A.I. AU - Gurnevich, E.A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Cherenkov Radiation in Periodic Wire Medium Formed by Transversely Modulated Electron Beams J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We investigate the properties of Cherenkov, quasi-Cherenkov (parametric) and diffraction radiation generated in the periodic conducting wire medium by transversely modulated electron beams. Such beams were recently obtained at Argonne Wakefield Accelerator (AWA) facility using microlens array (MLA) laser shaping technique. We consider in details the case of one dimensional periodic tungsten wire structure and transverse electron beamlets separation of mm scale. We look at possible enhancements of the radiation field due to transverse periodicity of the electron beam. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1878 EP - 1880 KW - radiation KW - electron KW - laser KW - cathode KW - experiment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB092 UR - http://jacow.org/ipac2019/papers/tuprb092.pdf ER - TY - CONF AU - Kim, K.-J. AU - Assoufid, L. AU - Decker, F.-J. AU - Huang, Z. AU - Lindberg, R.R. AU - Marcus, G. AU - Raubenheimer, T.O. AU - Shi, X. AU - Shu, D. AU - Shvyd'ko, Yu. AU - White, M. AU - Zhu, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Test of an X-ray Cavity using Double-Bunches from the LCLS Cu-Linac J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We discuss a proposal to test the operation of an X-ray cavity consisting of Bragg reflectors. The test will con-stitute a major step demonstrating the feasibility of either an X-ray regenerative amplifier FEL or an X-ray FEL Oscillator. These cavity-based X-ray FELs will provide the full temporal coherence lacking in the SA-SE FELs. An X-ray cavity of rectangular path will be constructed around the first seven LCLS-II undulator units. The Cu-linac will produce a pair of electron bunches separated by the cavity-round-trip distance during each linac cycle. The X-ray pulse produced by the first bunch is deflected into the cavity and returns to the undulator where it is amplified due to the presence of the second bunch. The key challenges are: the preci-sion of the cavity mechanical construction, the quality of the diamond crystals, and the electron beam stability. When the LCLS-II super-conducting linac becomes available, the cavity can then be used for high-repetition rate studies of the X-ray RAFEL and XFELO concepts. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1887 EP - 1890 KW - FEL KW - cavity KW - electron KW - laser KW - free-electron-laser DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB096 UR - http://jacow.org/ipac2019/papers/tuprb096.pdf ER - TY - CONF AU - Tian, K. AU - Li, Z. AU - Ringwall, A. AU - Sebek, J.J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Damping Trapped Modes in an in-Vacuum Undulator at a Synchrotron Radiation 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 - In this paper, we report the efforts in solving the problem of coupled-bunch instabilities caused by an in-vacuum undulator in the SPEAR3 storage ring. After exploring several approaches to reduce the strength of the trapped modes, we found that ferrite dampers were the most effective and simplest way for mode damping in our SPEAR3 in-vacuum undulator. The results of the first RF cold measurement on an in-vacuum undulator equipped with these ferrite dampers agree well with numerical simulations. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1895 EP - 1898 KW - simulation KW - vacuum KW - damping KW - HOM KW - impedance DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB101 UR - http://jacow.org/ipac2019/papers/tuprb101.pdf ER - TY - CONF AU - Tian, K. AU - Nuhn, H.-D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Numerical Study of the Delta II Polarizing Undulator for LCLS II J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Delta undulator has been operated successfully in LCLS with full control of the polarization mode and K value of the device. In LCLS II, a new Delta II undulator will be based on a similar design but with some differences. In this paper, we will present numerical simulation results that provide guidance to choose the geometric shape of the magnet poles and define the required tolerance for assembling the undulator magnets. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1899 EP - 1902 KW - undulator KW - simulation KW - polarization KW - electron KW - laser DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB102 UR - http://jacow.org/ipac2019/papers/tuprb102.pdf ER - TY - CONF AU - Nosochkov, Y.M. AU - Cai, Y. AU - Lin, F. AU - Morozov, V.S. AU - Zhang, Y. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Dynamic Aperture of JLEIC Electron Collider Ring with Errors and Correction J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Design of the Jefferson Lab Electron-Ion Collider (JLEIC) includes low-beta Interaction Region (IR) and spin rotator optics for high luminosity and polarization. Magnet errors, especially in the high-beta final focus quadrupoles, result in optics perturbations which need to be corrected in order to attain sufficient dynamic aperture (DA). We present design of orbit correction system for the electron ring and evaluate its performance. The DA is then studied including misalignment, magnet strength errors, non-linear field errors, and corrections. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1920 EP - 1923 KW - alignment KW - electron KW - multipole KW - optics KW - quadrupole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB113 UR - http://jacow.org/ipac2019/papers/tuprb113.pdf ER - TY - CONF AU - Lewis, S.M. AU - Dolgashev, V.A. AU - Haase, A.A. AU - Kim, D. AU - Nanni, E.A. AU - Othman, M.A.K. AU - Simakov, E.I. AU - Sy, A.V. AU - Tantawi, S.G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Design of a High Gradient THz-Driven Electron Gun 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 the design of a high-gradient electron gun. The goal of this gun is to generate relativistic electrons using GV/m accelerating fields. The initial design is a standing-wave field-emission gun operating in the pi-mode with a cavity frequency of 110.08 GHz. A pulsed 110 GHz gyrotron oscillator will be used to drive the structure with power coupled in through a TM01 circular waveguide mode. The gun is machined in two halves which are bonded. This prototype will be used to characterize the electron beam and study RF breakdown at 110 GHz. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2098 EP - 2100 KW - electron KW - gun KW - acceleration KW - experiment KW - FEL DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPTS077 UR - http://jacow.org/ipac2019/papers/tupts077.pdf ER - TY - CONF AU - Zhou, F. AU - Adolphsen, C. AU - Benwell, A.L. AU - Brown, G.W. AU - Colocho, W.S. AU - Ding, Y. AU - Dunning, M.P. AU - Grouev, K. AU - Huang, G. AU - Jacobson, B.T. AU - Liu, X. AU - Maxwell, T.J. AU - Sannibale, F. AU - Schmerge, J.F. AU - Smith, T.J. AU - Vecchione, T. AU - Wang, F.Y. AU - Zimmer, C.M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - First Commissioning of LCLS-II CW Injector 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 LCLS-II injector source includes a 186MHz CW rf-gun, a 1.3 GHz CW rf-buncher, a loadlock system for photocathode change, two main solenoids, and a few essential diagnostics. The electron beam is designed to operate at a high repetition rate, up to 1-MHz. Since summer of 2018 we started LCLS-II injector source commissioning immediately after the major installation was completed. Initial commissioning showed the rf-gun was severely contaminated with hydrocarbons and very limited power <600W could be fed into the gun cavity. After a few significant processes, we eventually removed the hydrocarbons and successfully delivered desired rf power of 80 kW to the gun. This paper reports first com-missioning results including gun bakeout and vacuum processing, CW RF-gun and buncher operation with nom-inal power, and measurements of rf stability and dark current. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2171 EP - 2173 KW - gun KW - cavity KW - operation KW - electron KW - vacuum DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPTS106 UR - http://jacow.org/ipac2019/papers/tupts106.pdf ER - TY - CONF AU - Lutman, A.A. AU - Bane, K.L.F. AU - Ding, Y. AU - Emma, C. AU - Guetg, M.W. AU - Guo, G. AU - Hemsing, E. AU - Huang, Z. AU - Krzywiński, J. AU - MacArthur, J.P. AU - Marcus, G. AU - Marinelli, A. AU - Maxwell, T.J. AU - Novokhatski, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - XFEL Operational Flexibility due to the Dechirper 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 RadiaBeam/SLAC dechirper was installed to demonstrate the concept of using wakefields from a corrugated structure to change the energy profile along an electron bunch. Since installation, the system has allowed a large number of additional XFEL operating modes including fresh-slice two-color or three color operation, fresh-slice seeding, passive streaking, etc. This talk will discuss the results from using the dechirper system and possible implementation issues related to the high-rate LCLS-II. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2219 EP - 2223 KW - electron KW - undulator KW - FEL KW - controls KW - laser DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEXPLM1 UR - http://jacow.org/ipac2019/papers/wexplm1.pdf ER - TY - CONF AU - Allaria, E. AU - Badano, L. AU - De Ninno, G. AU - Di Mitri, S. AU - Diviacco, B. AU - Fawley, W.M. AU - Ferrari, E. AU - Garzella, D. AU - Grattoni, V. AU - Hemsing, E. AU - Mirian, N.S. AU - Penco, G. AU - Pop, M.A. AU - Prat, E. AU - Rebernik Ribič, P. AU - Roussel, E. AU - Spampinati, S. AU - Spezzani, C. AU - Trovò, M. AU - Xiang, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Amplified Emission of a Soft-X Ray Free-Electron Laser Based on Echo-Enabled Harmonic Generation 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 first evidence of substantial gain in a soft-X ray Free Electron Laser (FEL) based on Echo-Enabled Harmonic Generation (EEHG). The experiment was focused on harmonics 36 (~7.3nm) and 45 (5.8 nm) and clearly demonstrated the expected EEHG capability of generating powerful and coherent FEL pulses, with strongly reduced sensitivity to electron-beam fluctuations. The experiment was carried out at FERMI, the seeded FEL user facility at Elettra-Sincrotrone Trieste. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2230 EP - 2232 KW - FEL KW - laser KW - electron KW - experiment KW - free-electron-laser DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEXXPLM1 UR - http://jacow.org/ipac2019/papers/wexxplm1.pdf ER - TY - CONF AU - Nosochkov, Y.M. AU - Hast, C. AU - Markiewicz, T.W. AU - Nicolas, L.Y. AU - Raubenheimer, T.O. AU - Santana-Leitner, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Simulations of Beam Shaping for Dark Matter Experiments at LCLS-II 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 transfer beamline, called S30XL, and an experimental facility are proposed to be built at SLAC, taking advantage of the LCLS-II free electron laser (FEL) under construction. The S30XL will operate parasitically to the FEL by extracting the unused low intensity 4-GeV LCLS-II bunches into the existing A-line and the End Station-A (ESA). This provides a unique capability of multi-GeV nearly continuous electron beam for a variety of HEP experiments, in particular the dark matter search experiments. The latter require a very low beam current ranging from pA to micro-A, as well as a large beam spot at the detector. The necessary beam shaping will be performed using spoilers and collimators in the A-line, and by optimizing the optics. FLUKA and elegant codes are used to generate and track the beam into the ESA. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2443 EP - 2446 KW - electron KW - experiment KW - FEL KW - optics KW - quadrupole DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP049 UR - http://jacow.org/ipac2019/papers/wepmp049.pdf ER - TY - CONF AU - Tian, K. AU - Langton, J. AU - Sebek, J.J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Impedance Study of a New Septum Chamber of SPEAR3 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 Septum magnet and chamber has been designed for the storage ring as a part of the accelerator improvement plan for operating a lower emittance lattice in SPEAR3. Therefore it is necessary to analyze the impedance effects on the beam from the new Septum chamber. Due to the complex design at the downstream transition of the Septum chamber, the longitudinal impedance is particular of concern. In this paper, we will present numerical simulation results for this particular component as well as the general analysis for the impedance effects of the whole chamber. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2447 EP - 2450 KW - impedance KW - septum KW - simulation KW - vacuum KW - storage-ring DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPMP051 UR - http://jacow.org/ipac2019/papers/wepmp051.pdf ER - TY - CONF AU - Kehrer, B. AU - Brosi, M. AU - Bründermann, E. AU - Funkner, S. AU - Müller, A.-S. AU - Niehues, G. AU - Patil, M.M. AU - Rota, L. AU - Schuh, M. AU - Steinmann, J.L. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Turn-by-Turn Horizontal Bunch Size and Energy Spread Studies at KARA 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 spread is an important beam dynamics parameter. It can be derived from measurements of the horizontal bunch size. At the KIT storage ring KARA a fast-gated camera is routinely used for horizontal bunch size measurements with a single-turn resolution for a limited time span. To overcome the limits of the current camera setup in respect to resolution and time span, a high-speed line array with up to 10 Mfps, the KALYPSO system, is foreseen as a successor. The KALYPSO versions range from 256-pixel to 1024-pixel and allow unlimited turn-by-turn imaging of a single bunch at KARA. We successfully tested such a system at our visible light diagnostics port and present first results in this contribution. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2498 EP - 2500 KW - synchrotron KW - radiation KW - detector KW - synchrotron-radiation KW - storage-ring DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW016 UR - http://jacow.org/ipac2019/papers/wepgw016.pdf ER - TY - CONF AU - Lin, F. AU - Cai, Y. AU - Morozov, V.S. AU - Nosochkov, Y.M. AU - Zhang, Y. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Update on the JLEIC Electron Collider Ring 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 design concept of electron collider ring in the Jefferson Lab Electron-Ion Collider (JLEIC) is based on a small beam size at the interaction point (IP) to boost the luminosity. With a chosen beta-star at the IP, electron beam size is determined by the equilibrium emittance obtained from the linear optics design. In this paper, we present an update on the lattice design of the electron ring considering not only preservation of low beam emittance, but also optimization of geometric arrangement. In particular, recent development of the lattice design has been focused on incorporating the vertical dogleg, which brings the electron beam to the ion beam plane for collisions, in the spin rotator design. The vertical dogleg is designed with no horizontal emittance growth, controlled vertical emittance and no first-order effect on the electron polarization. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2780 EP - 2782 KW - electron KW - collider KW - optics KW - quadrupole KW - solenoid DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW121 UR - http://jacow.org/ipac2019/papers/wepgw121.pdf ER - TY - CONF AU - Morozov, V.S. AU - Cai, Y. AU - Ent, R. AU - Furletova, Y. AU - Lin, F. AU - Michalski, T.J. AU - Nosochkov, Y.M. AU - Rajput-Ghoshal, R. AU - Sabbi, G.L. AU - Sullivan, M.K. AU - Wiseman, M. AU - Yoshida, R. AU - Zhang, Y. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Full Acceptance Interaction Region Design of JLEIC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Nuclear physics experiments envisioned at a proposed future Electron-Ion Collider (EIC) require high luminosity of 10³³-10³⁴ cm⁻²s⁻¹ and a full-acceptance detector capable of reconstruction of a whole electron-ion collision event. Due to a large asymmetry in the electron and ion momenta in an EIC, the particles associated with the initial ion tend to go at very small angles and have small rigidity offsets with respect to the initial ion beam. They are detected after they pass through the apertures of the final focusing quadrupoles. Therefore, the apertures must be sufficiently large to provide the acceptance required by experiments. In addition, to maximize the luminosity, the final focusing quadrupoles must be placed as close to the interaction point as possible. A combination of these requirements presents serious detection, optics and engineering design challenges. We present a design of a full-acceptance interaction region of Jefferson Lab Electron-Ion Collider (JLEIC). The paper presents how this design addresses the above requirements up to an ion momentum of 200 GeV/c. We summarize the magnet parameters, which are kept consistent with the Nb-Ti superconducting magnet technology. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2787 EP - 2790 KW - electron KW - detector KW - dipole KW - coupling KW - interaction-region DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW123 UR - http://jacow.org/ipac2019/papers/wepgw123.pdf ER - TY - CONF AU - Faillace, L. AU - Behtouei, M. AU - Dolgashev, V.A. AU - Spataro, B. AU - Torrisi, G. AU - Variola, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Compact Ultra High-Gradient Ka-Band Accelerating Structure for Research, Medical and Industrial Applications J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Technological advancements are strongly required to fulfil demands for new accelerators devices from the compact or portable devices for radiotherapy to mo-bile cargo inspections and security, biology, energy and environmental applications, and ultimately for the next generation of colliders. In the frame of the collab-oration with INFN-LNF, SLAC (USA) we are working closely on design studies, fabrication and high-power operation of Ka-band accelerating structures. In par-ticular, new manufacturing techniques for hard-copper structures are being investigated in order to determine the maximum sustainable gradients above 150 MV/m and extremely low probability of RF breakdown. In this paper, the preliminary RF and mechanical design as well as beam dynamics estimations for a Ka-Band accelerating structure at 35 GHz are presented together with discussions on practical accelerating gradients and maximum average beam current throughput. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2842 EP - 2845 KW - linac KW - electron KW - accelerating-gradient KW - operation KW - gun DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB020 UR - http://jacow.org/ipac2019/papers/weprb020.pdf ER - TY - CONF AU - Torrisi, G. AU - Castorina, G. AU - Celona, L. AU - Dolgashev, V.A. AU - Faillace, L. AU - Gammino, S. AU - Leonardi, O. AU - Mauro, G.S. AU - Sorbello, G. AU - Spataro, B. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Low Power RF Test of a Quadrupole-free X-Band Mode Launcher for High Brightness Applications 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 work we present the low power RF characterization of a novel TM01 X-band mode launcher for the new generation of high brightness RF photo-injectors. The proposed mode launcher exploits a fourfold symmetry which minimizes both the dipole and the quadrupole fields in order to mitigate the emittance growth in the early stages of the acceleration process. Two identical aluminum mode launchers have been assembled and measured in back-to-back configurations for three different central waveguide lengths. From the back-to-back results we infer the performance of each mode launcher. The low power RF test, performed at the Istituto Nazionale di Fisica Nucleare Laboratori Nazionali del Sud (INFN-LNS), validate both the numerical simulations and the quality of fabrication. An oxygen-free high-conductivity copper version of the device is being manufactured for high power and ultra high vacuum tests that are planned to be conducted at SLAC PB - JACoW Publishing CP - Geneva, Switzerland SP - 2856 EP - 2859 KW - GUI KW - brightness KW - quadrupole KW - simulation KW - electron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB024 UR - http://jacow.org/ipac2019/papers/weprb024.pdf ER - TY - CONF AU - De Silva, S.U. AU - Delayen, J.R. AU - Li, Z. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Simulation and Measurements of HOM Filter of the LARP Prototype RF-Dipole Crabbing Cavity Using an RF Test Box J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The RF-Dipole Crabbing Cavity designed for the LHC High Luminosity Upgrade includes two higher order mode (HOM) couplers. One of the HOM couplers is an rf filter, which is a high pass filter designed to couple to the horizontal dipole modes and accelerating modes up to 2 GHz, while rejecting the fundamental operating mode at 400 MHz. The coupler consists of a high pass filter circuit where the rejection of the operating mode and transmission of HOMs are sensitive to dimensional deviations. An rf test box has been designed to measure the transmission of the rf filter in order to qualify the fabricated HOM coupler and to tune the coupler. This paper presents the measurements of the HOM coupler with the rf test box. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2999 EP - 3002 KW - HOM KW - cavity KW - dipole KW - luminosity KW - damping DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB077 UR - http://jacow.org/ipac2019/papers/weprb077.pdf ER - TY - CONF AU - Nasr, M.H. AU - Li, Z. AU - Tantawi, S.G. AU - Welander, P.B. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - The Design of Parallel-Feed SC RF Accelerator Structure J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Development of superconducting RF (SRF) accelerator technology that enables both higher gradient and higher efficiency is crucial for future machines. While much of the recent R&D focus has been on materials and surface science, our aim is to optimize the cavity geometry to maximize performance with current materials. The recent demonstration of a highly efficient parallel-feed normal-conducting RF structure at SLAC has served as a proof-of-concept. Instead of coupled elliptical cells, the structure employs isolated re-entrant cells. To feed RF power to the cavities, each cell is directly coupled to an integrated manifold. The structure is made in two parts, split along the beam axis, which are then joined. Applied to SRF, simulations suggest such a structure could nearly double the achievable gradient, while reducing cryogenic RF loss by more than half. We are experimentally verifying the concept using an X-band SRF design to be tested at SLAC. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3024 EP - 3026 KW - cavity KW - SRF KW - coupling KW - niobium KW - alignment DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB090 UR - http://jacow.org/ipac2019/papers/weprb090.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 - Bafia, D. AU - Checchin, M. AU - Gonnella, D. AU - Grassellino, A. AU - Martinello, M. AU - Melnychuk, O.S. AU - Palczewski, A.D. AU - Posen, S. AU - Romanenko, A.S. AU - Sergatskov, D.A. AU - Zasadzinski, J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Understanding and Pushing the Limits of Nitrogen Doping J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - This work will describe Fermilab experiments that focus on the optimization of doping parameters to achieve low sensitivity to trapped magnetic flux while maintaining very high Q characteristic of nitrogen doped cavities and same or higher quench fields. Working partially in the context of LCLS-2 higher energy upgrade, new doping recipes are pursued and have been found to vary the mean free path of the resonator which is related to the sensitivity to trapped magnetic flux. Moreover, a correlation has been found between lighter doping and higher quench fields while maintaining sufficiently low surface resistance. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3078 EP - 3081 KW - cavity KW - SRF KW - niobium KW - experiment KW - ECR DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB114 UR - http://jacow.org/ipac2019/papers/weprb114.pdf ER - TY - CONF AU - Deng, X.J. AU - Chao, A. AU - Huang, W.-H. AU - Tang, C.-X. AU - Zhang, Y. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Transverse-Longitudinal Coupling for Harmonic Generation and Bunch Length Manipulation J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A general harmonic generation and bunch length manipulation scheme using transverse-longitudinal coupling is presented. The method makes use of the freedom in projecting the three beam eigen-emittances into different physical dimensions. A realization of this coupling lattice, a PEHG variant, is given as an example. For the purpose of harmonic generation and bunch compression, this method is advantageous when the transverse emittance is small. The combination with sawtooth waveform modulation is proposed to boost the bunching further. Transverse-longitudinal coupling in storage rings are briefly discussed. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3160 EP - 3163 KW - emittance KW - bunching KW - coupling KW - lattice KW - storage-ring DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS028 UR - http://jacow.org/ipac2019/papers/wepts028.pdf ER - TY - CONF AU - Qiang, J. AU - Bizzozero, D.A. AU - Ge, L. AU - Li, Z. AU - Ng, C.-K. AU - Xiao, L. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Integration of Cavity Design and Beam Dynamics Simulation Using the Parallel IMPACT and the ACE3P Codes J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The 3D parallel code suite IMPACT has been extensively used in the beam dynamics study of photoinjectors while the 3D parallel code ACE3P has been extensively used in the RF cavity design. In this paper, we propose integrating the ACE3P cavity design and the IMPACT beam dynamics simulation into a single work flow. Such a workflow enables efficient simulation of 3D effects(e.g. RF coupler) on high performance computers. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3317 EP - 3320 KW - cavity KW - simulation KW - emittance KW - electron KW - gun DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS088 UR - http://jacow.org/ipac2019/papers/wepts088.pdf ER - TY - CONF AU - Wu, J. AU - Qiang, J. AU - Raubenheimer, T.O. AU - Woodley, M.D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Emittance Preservation for LCLS-II-HE Project J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A small transverse slice emittance at the undulator entrance is essential for high performance of the free electron laser. To achieve this, preservation of the phase space density of the electron bunch during acceleration and compression is absolutely necessary. The LCLS-II-HE is designed to transport a 100 pC bunch with an emittance of ~0.3 mm-mrad with minimal emittance dilution. However, in simulations starting from a normalized emittance on the order of 0.1 mm-mrad, the emittance growth is significant. In this paper, the sources of emittance growth are studied along the accelerator, in particular, around the laser-heater, the two bunch compressors. We have investigated mechanisms of emittance growth such as space charge, coherent synchrotron radiation, chromatic aberration, and spurious dispersion. Due to the extremely small emittance from the injector, 3-D space charge effect is important to determine the space charge dominated region and emittance dominated region. With this understanding, emittance preservation schemes are proposed. Studies are carried out with IMPACT simulation code, as well as ASTRA and ELEGANT. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3333 EP - 3336 KW - emittance KW - electron KW - lattice KW - laser KW - space-charge DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPTS093 UR - http://jacow.org/ipac2019/papers/wepts093.pdf ER - TY - CONF AU - Leitner, M. AU - Arbelaez, D. AU - Bassan, H. AU - Bruch, D.E. AU - Chen, C.W. AU - Corlett, J.N. AU - DeMello, A.J. AU - Garcia Fajardo, L. AU - Leitner, D. AU - Marks, S. AU - Martinez-Galarce, D.S. AU - McCombs, K.A. AU - Miller, T. AU - Munson, D.V. AU - Niu, J. AU - Nuhn, H.-D. AU - Ray, K.L. AU - Rowen, M. AU - Sadlier, D.A. AU - Schlueter, D. AU - Wallén, E.J. AU - Wolf, Z.R. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Development of the Vertically Polarizing Hard X-Ray Undulator Segments for the Linear Coherent Light Source Upgrade (LCLS-II) 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 Linear Coherent Light Source II (LCLS-II) is a free electron laser facility currently in its final construction stage at Stanford Linear Accelerator Center. The project includes two variable-gap, hybrid-permanent-magnet undulator lines: A soft x-ray undulator line with 21 undulator segments optimized for a photon energy range from 0.2 keV to 1.3 keV and a hard x-ray undulator line with 32 undulator segments designed for a photon energy range from 1.0 keV to 25.0 keV. This paper focuses on the design, development, and performance of the hard x-ray undulator line which utilizes uniquely-developed, vertically-polarizing undulators. To fully compensate the magnetic force throughout the entire gap range these devices incorporate non-linear spring systems which permit the construction of relatively compact undulators. However, significant magnetic field repeatability challenges have been encountered during prototyping of this novel design. The paper describes the innovative design improvements that were implemented which lead to reaching the LCLS-II required performance. These final design solutions can also be advantageous improving the operation of any future undulator design. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3408 EP - 3413 KW - undulator KW - photon KW - operation KW - free-electron-laser KW - electron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THYPLM1 UR - http://jacow.org/ipac2019/papers/thyplm1.pdf ER - TY - CONF AU - Othman, M.A.K. AU - Angier, B.J. AU - Haase, A.A. AU - Nanni, E.A. AU - Roux, M.R. AU - Sy, A.V. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Prototyping of Brazed mm-Wave 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 - Advanced fabrication and prototyping of metallic RF structures play a fundamental role in advancing accelerator technologies particularly at mm-wave and THz frequencies. With the scaling of the RF structure up to these frequencies, conventional fabrication techniques do not achieve the required accuracy and tolerances. Improved manufacturing techniques including diffusion bonding, brazing or clamping split-block geometries produce high quality structures when successfully implemented. However, in most schemes the resulting gap and irregularities at the iris result in a local field enhancement which is not desirable for high-gradient operation. Development of advanced split-block braze technique for THz accelerators was required for high quality miniature accelerators. A new braze technique was developed for W-band structures to control the flow of braze alloy, enabling fabrication of the first high-gradient brazed structures at mm-wave frequencies. This fabrication process has the potential to overcome consistent fabrication defects around the cell iris. Thin spacers were used to set the final gap between blocks during the braze process; while braze foil thickness is varied with minimal impact on the resulting frequency. To demonstrate the robustness of this technique, testing after the various manufacturing steps was done to monitor and track frequency change throughout the process. This technique is further pushed to produce G-band RF structures, operating at 300 GHz. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3764 EP - 3765 KW - cavity KW - resonance KW - simulation KW - GUI KW - RF-structure DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW078 UR - http://jacow.org/ipac2019/papers/thpgw078.pdf ER - TY - CONF AU - Othman, M.A.K. AU - Hoffmann, M.C. AU - Kozina, M.E. AU - Li, R.K. AU - Nanni, E.A. AU - Shen, X. AU - Snively, E.J. AU - Wang, X.J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - THz-Based Femtosecond MeV Electron Bunch Compression J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Probing structural dynamics at atomic spatial and ultrashort temporal scales reveals unprecedented details of fundamental behavior of nature, allowing for better understanding of intricate energy-matter interaction occurring at such scales. Developing state-of-the-art technology to access these details entails utilizing X-ray free-electron lasers (XFELs), ultrafast electron diffraction (UED), and advanced electron microscopes. In particular, ultrafast diffraction science received growing attention thanks to innovation in sources, detectors and instrumentation in general. Within this context, interest in laser-generated THz wave-matter interaction has recently emerged as a new regime for controlling electrons with high temporal precision. Previously, the SLAC UED team has demonstrated attosecond electron metrology using laser-generated single-cycle THz radiation, which is intrinsically phase locked to the optical drive pulses, to manipulate multi-MeV relativistic electron beams. Here we demonstrate further steps towards achieving ultrafast timing resolution that utilizes femtosecond electron bunches. The proposed setup allows for compressing electron beam bunches down to a femtosecond using interaction with high field single-cycle THz pulses. We demonstrate a novel design of a dispersion-free parallel-plate tapered waveguide that provides focusing of THz pulses achieving >100 MV/m field strength at the interaction point as measured by electro-optical sampling for ~7 μJ of incoming THz pulse energy. The structure is being designed and built for bunch compression experiments using the SLAC UED facility. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3766 EP - 3768 KW - electron KW - FEM KW - GUI KW - experiment KW - focusing DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW079 UR - http://jacow.org/ipac2019/papers/thpgw079.pdf ER - TY - CONF AU - Othman, M.A.K. AU - Dolgashev, V.A. AU - Haase, A.A. AU - Jawla, S. AU - Nanni, E.A. AU - Neilson, J. AU - Picard, J.F. AU - Schaub, S.C. AU - Spataro, B. AU - Tantawi, S.G. AU - Temkin, R.J. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Initial Results of High-Gradient Breakdown Tests for W-Band 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 - Emerging accelerator technology at mm-wave and THz frequencies has recently shown notable progress. Indeed, metallic and dielectric accelerating structures at THz frequencies are plausible candidates toward miniaturization of accelerators. RF breakdown in such structures is a major factor limiting their performance. Therefore, comprehensive analysis of RF breakdown physics in mm-wave accelerating structures is needed, which includes understanding of dependencies of the breakdown rate on geometric, electromagnetic and material properties. In this work we report on high power tests of a 110 GHz single-cell standing wave accelerating structure powered by a 1 MW gyrotron. The RF power is coupled from the gyrotron into the accelerating structure with a Gaussian to TM01 mode converter through a quasi-optical setup. We demonstrate coupling of 10 ns, 100s of kilowatt pulses into the structure using a fast switch and achieving ~150 MV/m accelerating gradients. Measurements of RF signals and field-emitted currents allow for complete comprehensive of the high-gradient behavior of W-band structures, including breakdown probability. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3769 EP - 3771 KW - cavity KW - experiment KW - electron KW - laser KW - vacuum DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW080 UR - http://jacow.org/ipac2019/papers/thpgw080.pdf ER - TY - CONF AU - Nasr, M.H. AU - Tantawi, S.G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Corrections of Klystron Output Pulse in SW Accelerator Testing J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Accelerator testing requires a good control over the shape of the used pulse. Usually, flat or stepped square pulses are used for testing. Producing a perfectly flat output pulse from the klystron can be challenging especially for testing standing wave (SW) accelerators. SW accelerator structures reflect high power back to the klystron and no isolator can withstand the reflected power level for high gradient operation. This results in a distorted output pulse from the Klystron. We developed a modulation technique that solves this problem using a negative feedback loop. This technique can also overcome a poor modulator performance and other system errors. The pulse correction feedback was successfully implemented for high gradient SW accelerator testing at SLAC and KEK. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3772 EP - 3773 KW - klystron KW - controls KW - feedback KW - linac KW - ISOL DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW084 UR - http://jacow.org/ipac2019/papers/thpgw084.pdf ER - TY - CONF AU - White, G.R. AU - Raubenheimer, T.O. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Transverse Jitter Tolerance Issues for Beam-Driven Plasma Accelerators J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Transverse jitter tolerances are considered for beam-driven plasma accelerators. A simple model for jitter transfer from the drive to witness beam is developed and concrete examples are studied for: high-brightness witness bunch injectors; high-energy boosters for FEL’s; and future Linear Colliders. Compared with an existing PWFA driver facility ([*,**]), the calculated tolerances are 18X ’ 170X tighter than achievable, even considering any upgrades with existing technology. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3774 EP - 3777 KW - plasma KW - emittance KW - acceleration KW - FEL KW - electron DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPGW087 UR - http://jacow.org/ipac2019/papers/thpgw087.pdf ER - TY - CONF AU - Santana-Leitner, M. AU - Clarke, C.I. AU - Fisher, A.S. AU - Griesmayer, E. AU - Harris, A.M. AU - Hast, C. AU - Liang, T.T. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Monte Carlo Optimization of Fast Beam Loss Monitors for LCLS-II J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Commissioning of the LCLS-II hard X-ray FEL is starting at SLAC National Accelerator Laboratory. This facility will ultimately accelerate electrons to 8 GeV, with beams of 375 kW at 1 MHz. At such high-powers, errant beams will need to be detected very fast -200 μs- to limit exposure and to protect beam-line and safety components. Currently, LCLS-I uses ion chambers both as Point Beam Loss Monitors (PBLM) by collimators, dumps, septa, etc., and also as Long Beam Loss Monitors (LBML) that provide detection coverage in extended areas where the accelerator enclosure is not sufficiently thick to shield full beam losses. But due to the finite ion mobility and related screening effects, ion chambers are not fast enough, and their response would not be linear at high charge rates. LCLS-II will use synthetic mono-crystalline diamond chips as PBLMs, as those offer nanosecond time resolution due to the high mobility of holes generated in the valence band by charged particles. LBLMs will be 200 m-long optical fibers, with photomultipliers to detect Cerenkov photons produced by charged particles in the fibers. Use of these technologies requires tests and models to correlate their response to different beam losses. Response functions for these detectors have been developed for the FLUKA Monte Carlo code. After benchmarking the models, these have been applied to place PBLMs at locations where signal is relatively insensitive to beam-strike uncertainties and sufficiently above electronic noise, while keeping lifetime to radiation-damage long. Also, topologies where found were one PBLM can protect several components, resulting in cost reductions. As for LBLMs, the existing model helps scale signals for different beam loss configurations as a function of the fiber position. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4066 EP - 4069 KW - detector KW - target KW - photon KW - electron KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB102 UR - http://jacow.org/ipac2019/papers/thprb102.pdf ER - TY - CONF AU - Tian, K. AU - Corbett, W.J. AU - Huang, X. AU - Kurita, N. AU - Martin, D.J. AU - Safranek, J.A. AU - Sebek, J.J. AU - Teytelman, D. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Commission of the Transverse Bunch-by-Bunch Feedback at SPEAR3 J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Driven by the demand of suppressing transverse beam instabilities and developing novel short pulse operation modes in SPEAR3 storage ring, a wide-band transverse bunch-by-bunch feedback system has been recently commissioned for SPEAR3 storage ring. The system was demonstrated to be sufficient to suppress the transverse coupled bunch instabilities caused by trapped RF modes in one of the in vacuum insertion devices. A new function of beam instability interlock has been developed and is part of machine protection system for the in vacuum insertion device. In addition, the bunch-by-bunch feedback system serves as a indispensable diagnostic tool that enables us to measure machine parameters, beam impedance, and characteristics of the beam instability modes. In this paper, we describe the scheme and performance of the bunch-by-bunch feedback system at SPEAR3. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4081 EP - 4084 KW - feedback KW - kicker KW - injection KW - vacuum KW - GUI DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB112 UR - http://jacow.org/ipac2019/papers/thprb112.pdf ER - TY - CONF AU - Toufexis, F. AU - Angier, B.J. AU - Gamzina, D. AU - McGuire, A. AU - Shumail, M. AU - Tantawi, S.G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Development of a W-Band Power Extraction Structure J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We are modifying the X-Band Test Accelerator at SLAC to operate as an Extreme Ultra Violet (EUV) light source*. The existing photo electron gun will be replaced by a thermionic X-Band injector which utilizes RF bunch compression. The beam is accelerated up to 129 MeV using an X-Band traveling wave structure followed by a novel high shunt impedance standing wave structure. The beam then goes through a mm-wave undulator with a period of 1.75 mm, producing EUV radiation around 13.5 nm. The undulator is powered by a W-Band decelerator structure, which extracts the RF power from the electron beam. In this work we present the mechanical design and fabrication of the 91.392 GHz decelerator structure, as well as structural characterization of its cavities using SEM and 3D microscopy. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4252 EP - 4255 KW - cavity KW - undulator KW - electron KW - GUI KW - extraction DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPTS063 UR - http://jacow.org/ipac2019/papers/thpts063.pdf ER - TY - CONF AU - Toufexis, F. AU - Dolgashev, V.A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Sub-Picosecond X-Ray Streak Camera using High-Gradient RF Cavities J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - We are developing an ultrafast diagnostic system for X-ray beams from Synchrotron Light Sources and Free-Electron Lasers. In this system, the X-ray beam is focused on the photocathode of a high-gradient radio-frequency cavity that accelerates the photo-emitted electrons to a few MeV while preserving their time structure. The accelerated electron beam is streaked by radio-frequency deflectors and then imaged on a screen. This approach will allow orders of magnitude improvement in time resolution over traditional streak cameras and could potentially enable time-resolved diagnostics of sub-100 fs X-ray pulses. We present preliminary beam dynamics simulations of this system and discuss the implementation. PB - JACoW Publishing CP - Geneva, Switzerland SP - 4256 EP - 4259 KW - electron KW - cathode KW - photon KW - gun KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPTS064 UR - http://jacow.org/ipac2019/papers/thpts064.pdf ER -