TY - CONF AU - Bence, A. AU - Li, J. AU - Nadolski, L.S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - First Application of Online Particle Swarm Optimization at SOLEIL J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - First attempts of online optimisation of SOLEIL using Particle Swarm Optimisation (PSO) is reported with two major applications. This technique proves to be particularly suitable in a control room and could become a standard operation tool for tuning the accelerators in complement of other techniques. The first optimisation of the injection in the storage ring will be presented using the injection septa and the vertical correctors of the booster to storage ring transfer line. The second work will summarise the results obtained from the optimisation of the transverse on- and off-momentum dynamics in presence of insertion devices. Main results, the implementation and improvements will be presented and discussed thoroughly. PB - JACoW Publishing CP - Geneva, Switzerland SP - 82 EP - 85 KW - injection KW - storage-ring KW - operation KW - controls KW - vacuum DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW010 UR - http://jacow.org/ipac2019/papers/mopgw010.pdf ER - TY - CONF AU - Andreas, F. AU - Abo-Bakr, M. AU - Armborst, F. AU - Goslawski, P. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Developing Beam Optics for the BESSY VSR Project J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - At BESSY II due to the continuously increasing interest in short pulse operation, a major upgrade of the ring will enable simultaneous storage of long and short bunches. This Variable pulse-length Storage Ring (VSR) will be achieved by the installation of additional superconducting high gradient cavities. The cavities will be assembled into one cryomodule in one of the straights of the storage ring. As this module needs more space then initially assumed, one possible solution is to remove two quadrupoles to gain available installation length. The quadrupoles were switched off in simulations and the lattice was optimized with regard to the linear order. The best solution found was transferred to the storage ring, where storage of high current with reasonable injection efficiency and lifetime was possible. The proposed optics has to be further optimized in terms of nonlinear beam dynamics, but has shown that an available installation length can be increased. PB - JACoW Publishing CP - Geneva, Switzerland SP - 94 EP - 97 KW - optics KW - quadrupole KW - storage-ring KW - lattice KW - cavity DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW014 UR - http://jacow.org/ipac2019/papers/mopgw014.pdf ER - TY - CONF AU - Kuske, B.C. AU - Meseck, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Numerical Calculation of Micro Bunching in BERLinPro Due to Space Charge and CSR Effects J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - BERLinPro is an Energy Recovery Linac Project, currently being set up at the Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany. BERLinPro is a small demonstrator for ERL technology and applications. Due to the low energy of 50, resp. 32MeV, space charge plays a dominant role in the beam dynamics. Micro-bunching, due to unavoidable shot noise from the cathode in combination with space charge, is seen in the merger as well as in the recirculator. Coherent synchrotron radiation (CSR) can amplify this bunching, as well as micro-bunching can enhance CSR losses. With the release of OPAL 2.0** in May 2018, for the first time, an open source, highly parallel tracking code is available, that is capable of numerically calculating both effects, space charge and CSR, simultaneously. The calculations are compared to earlier results*, that used analytical formulas on tracked, space charge dominated bunches. PB - JACoW Publishing CP - Geneva, Switzerland SP - 116 EP - 119 KW - bunching KW - space-charge KW - linac KW - emittance KW - optics DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW020 UR - http://jacow.org/ipac2019/papers/mopgw020.pdf ER - TY - CONF AU - Li, J. AU - Feikes, J. AU - Mertens, T. AU - Petenev, Y. AU - Ries, M. AU - Schälicke, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Symplectic Tracking for the Robinson Wiggler J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - A Robinson wiggler (RW) is considered to be installed in the Metrology Light Source (MLS) to lengthen the bunch and improve the Touschek lifetime by manipulating the damping partitions. Symplectic tracking is crucial to study the impact of the nonlinear field components introduced by the Robinson wiggler. This paper introduces a tracking method based on an implicit symplectic integrator to solve the exact Hamiltonian equations of particle motion in the wiggler. In addition, a numerical generating function method is implemented as an approach to realize fast tracking. PB - JACoW Publishing CP - Geneva, Switzerland SP - 120 EP - 123 KW - wiggler KW - storage-ring KW - dynamic-aperture KW - electron KW - linear-dynamics DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW021 UR - http://jacow.org/ipac2019/papers/mopgw021.pdf ER - TY - CONF AU - Armborst, F. AU - Goslawski, P. AU - Jankowiak, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Tune and Chromaticity Optimization at Bessy II for the Transverse Resonant Island Bucket Optics J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Transverse Resonant Island Buckets (TRIBs *) correspond to a second stable orbit, longitudinally winding around the core orbit in the transverse x-x^{′}-phasespace. The exploitation possibilities for stable TRIBs are under investigation at the third generation light source BESSY II in Berlin. The applicability for bunch separation is a main subject of these studies. Stable operation of TRIBs optics with a single or few bunches on the second orbit and a multibunch train on the main orbit has been shown **. Photons emitted on the second orbit are well separated from those of the main orbit at all beamlines. This provides the possibility of bunch separation by beamline adjustment for the timing community without significant impact on the average brightness for other users. Simulations based on linear optics from closed orbits (LOCO) and on nonlinear optics derived from the measured chromaticity and tune shift with action (TSWA) predict this separation well. Friendly user experiments in 2018 confirmed these results. The scheduled upgrade BESSY VSR *** features simultaneously stored long and short bunches. Then TRIBs optics would in principle enable the separation of the different bunches at every beamline offering unique possibilities to our users. Simulations and measurements aiming to investigate further possible optimization of the TRIBs optics are presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1411 EP - 1414 KW - optics KW - simulation KW - photon KW - resonance KW - emittance DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPGW013 UR - http://jacow.org/ipac2019/papers/tupgw013.pdf ER - TY - CONF AU - Bahrdt, J. AU - Frentrup, W. AU - Gottschlich, S. AU - Grimmer, S. AU - Huck, M. AU - Kuhn, C. AU - Meseck, A. AU - Rethfeldt, C. AU - Rial, E.C.M. AU - Scheer, M. AU - Schulz, B. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Characterization and Implementation of the Cryogenic Permanent Magnet Undulator CPMU17 at Bessy II J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - In fall 2018, the cryogenic undulator CPMU17 was installed in BESSY II. Before installation, the undulator was characterized with an in-vacuum Hallprobe bench and an in-vacuum moving wire. Both systems were developed at HZB. The commissioning of the device included the orbit and tune corrections, optimization of the injection, characterization of the heat dissipation, tuning the Landau cavities for a reduction of the heat dissipation in the taper sections (temperatures below 60°C) and testing of the machine protection system. The undulator is ready to deliver light for beamline commissioning. Spectral tuning on a high undulator harmonic (longitudinal taper and alignment of e-beam orbit and undulator axis) will be done as soon as the DCM is operational. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1415 EP - 1418 KW - undulator KW - vacuum KW - laser KW - feedback KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPGW014 UR - http://jacow.org/ipac2019/papers/tupgw014.pdf ER - TY - CONF AU - Glock, H.-W. AU - Dürr, V. AU - Glöckner, F. AU - Guo, J. AU - Knobloch, J. AU - Rimmer, R.A. AU - Tannert, M. AU - Vélez, A.V. AU - Wang, H. AU - Wolk, D. AU - Wunderer, N. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Progress of the BESSY VSR Cold String Development and 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 so-called VSR (Variable Storage Ring) upgrade of the 3rd gen. light source BESSY II will provide the capability to simultaneously store long (about 20 ps rms length) and short (1 ps or less) bunches in the ring. This will be accomplished by inserting a module with four superconducting cavities, two of them operating at 1.5 GHz as the third harmonic of the 500 MHz driving RF, two at 1.75 GHz. The "cold" string of those four cavities also includes supporting and connecting devices, as there will be: - three intermediate bellows, all shielded against leaking fundamental mode cavity fields, one additionally acting as a collimator for incident synchrotron light; - two tuneable bellows at the module ends; - two warm end groups outside the module, housing toroidal dielectric wake field absorbers, another bellow and a vacuum pump connection. The recent design progress of those components will be reported, including a description of a beam test planned for the central collimating shielded bellow. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1434 EP - 1436 KW - cavity KW - GUI KW - simulation KW - experiment KW - vacuum DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPGW019 UR - http://jacow.org/ipac2019/papers/tupgw019.pdf ER - TY - CONF AU - Kuske, B.C. AU - Anders, W. AU - Aulenbacher, K. AU - Hug, F. AU - Jankowiak, A. AU - Neumann, A. AU - Stengler, T. AU - Stoll, C.P. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Incorporation of a MESA Linac Modules into BERLinPro J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - BERLinPro is an Energy Recovery Linac (ERL) project, currently being set up at the Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany. BERLinPro is designed as - and for - experiments in accelerator physics and as a test bed for novel ERL components. MESA is an ERL project under construction at the Johannes Gutenberg-Universität, Mainz, Germany. MESA is designed as a user facility to perform experiments in dark matter physics and precision measurements of natural constants. Despite the diverse goals, the main linac, providing the larger part of the particles energy, is fairly compatible. It is planned to test and run the MESA linac module in BERLinPro, prior to its usage in MESA. The goals and benefits of this unique cooperation for both projects are outlined in this paper. The necessary adaptions in BERLinPro, including hardware aspects, the new optics, and the scope of performance are described. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1449 EP - 1452 KW - linac KW - optics KW - operation KW - HOM KW - cavity DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPGW023 UR - http://jacow.org/ipac2019/papers/tupgw023.pdf ER - TY - CONF AU - Meseck, A. AU - Bahrdt, J. AU - Frentrup, W. AU - Huck, M. AU - Kuhn, C. AU - Rethfeldt, C. AU - Rial, E.C.M. AU - Scheer, M. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Triple Period Undulator J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Insertion devices are one of the key components of modern synchrotron radiation facilities. They allow for generation of radiation with superior properties enabling experiments in a variety of disciplines, such as chemistry, biology, crystallography and physics to name a few. For future cutting edge experiments in soft and tender x-rays users require high flux and variable Polarization over a wide photon energy range independent of other desired properties like variable pulse length, variable timing or Fourier transform limited pulses. In this paper, we propose a novel ID-structure, called Triple Period Undulator (TPU), which allow us to deliver a wide energy range from a few ten eV to a few keV at the same beamline with high flux and variable Polarization. The TPU are particularly interesting in context of BESSY III, the successor facility of BESSY II. PB - JACoW Publishing CP - Geneva, Switzerland SP - 1728 EP - 1731 KW - undulator KW - radiation KW - vacuum KW - photon KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-TUPRB022 UR - http://jacow.org/ipac2019/papers/tuprb022.pdf ER - TY - CONF AU - Koopmans, M. AU - Armborst, F. AU - Hwang, J.G. AU - Jankowiak, A. AU - Kuske, P. AU - Ries, M. AU - Schiwietz, G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Vertical Beam Size Measurement Methods at the BESSY II Storage Ring and their Resolution Limits J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - With the VSR upgrade for the BESSY II electron storage ring* bunch resolved diagnostics are required for machine commissioning and to ensure the long-term quality and stability of operation. For transverse beam size measurements we are going to use an interferometric method, which will be combined with a fast gated intensified CCD camera at a subsequent stage. A double-slit interferometer method has already been verified successfully at BESSY II**. In addition first 2D bunch resolved measurement tests have been performed at the dedicated diagnostics beamline for bunch length measurements. Measurements of the interferometer and X-ray pinholes as function of a vertical electron beam excitation are compared in this paper. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2491 EP - 2494 KW - diagnostics KW - storage-ring KW - electron KW - polarization KW - detector DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPGW012 UR - http://jacow.org/ipac2019/papers/wepgw012.pdf ER - TY - CONF AU - Echevarria, P. AU - Garcia, B. AU - Jugo, J. AU - Neumann, A. AU - Ushakov, A. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Simulation of Quench Detection Algorithms for Helmholtz Zentrum Berlin SRF Cavities J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Helmholtz Zentrum Berlin is carrying out two accelerator projects which make use of high gradient SRF cavities: BERLinPro* and BESSY-VSR**. In both projects, a prompt detection of a quench is crucial to avoid damages in the cryomodules and cavities themselves. In this paper, the response of real time estimation of the cavity parameters*** using the transmitted and forward RF signals is simulated, in order to perform the quench detection. The time response of the estimated half bandwidth is compared with the dissipated power in the cavity walls for the different type of SRF cavities used in both projects, i.e., BERLinPro’s photoinjector, booster and linac, and BESSY-VSR 1.5 GHz and 1.75 GHz cavities. As an intermediate step prior to the implementation in an mTCA.4 system together with the LLRF control and test with a real cavity, the algorithm has been implemented using a National Instruments FPGA board to check the its proper behavior. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2834 EP - 2837 KW - cavity KW - SRF KW - FPGA KW - LLRF KW - controls DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB016 UR - http://jacow.org/ipac2019/papers/weprb016.pdf ER - TY - CONF AU - Glock, H.-W. AU - Böhnel, M. AU - Kinzinger, J. AU - Knobloch, J. AU - Neumann, A. AU - Reims, N. AU - Tamashevich, Y. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Operational Experiences with X-Ray Tomography for SRF Cavity Shape and Surface Control J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - X-ray tomography has established as a non-destructive three-dimensional analysis tool, commercially offered by industrial vendors. Typical applications cover shape control and failure detection (voids, cracks) deep inside of complicated bulk pieces like engine blocks, bearings, turbine blades etc. We evaluated the applicability of the process for superconducting radio frequency cavities, in particular the 1.4-cell 1.3 GHz BERLinPro electron gun cavity and the 1.5 GHz single-cell VSR cavity prototype. The former experienced severe shape modifications during its tuning process and features a complicated internal stiffening construction. Thus it is a demanding challenge to measure its actual internal cavity surface shape after the complete preparation process with a resolution, sufficiently high (better than 0.2 mm) to serve as input for meaningful comparative field simulations. First tests with a vendor’s on-site X-ray source, operating at X-ray energies up to 590 keV revealed an insufficient resolution of the inner surface, attributed to the unfavorable X-ray damping characteristics of niobium. This was overcome with the aid of an accelerator-based source (X-ray spectrum up to 9 MeV), operated by Fraunhofer IIS, Fürth, Germany. Results both show significant, while understood, shape changes and indicate partial inner surface modifications of the gun cavity. Further the data evaluation process, which was needed to provide input for field simulations, raised issues because of the data set size and complexity, which are discussed in the paper. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2838 EP - 2841 KW - cavity KW - controls KW - gun KW - detector KW - simulation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB017 UR - http://jacow.org/ipac2019/papers/weprb017.pdf ER - TY - CONF AU - Goslawski, P. AU - Andreas, F. AU - Armborst, F. AU - Atkinson, T. AU - Feikes, J. AU - Jankowiak, A. AU - Li, J. AU - Mertens, T. AU - Ries, M. AU - Schiwietz, G. AU - Schälicke, A. AU - Wüstefeld, G. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Two Orbit Operation at Bessy II - During a User Test Week J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Operating a storage ring close to a horizontal resonance and manipulating the transverse non-linear beam dynamics can generate stable Transverse Resonance Island Buckets (TRIBs), which give a 2nd stable orbit in the ring. Both orbits can be populated with different electron bunch filling patterns and provide two different radiation sources to the user community. Such a machine setting has been established at BESSY II and was tested under realistic user conditions in a first ’TRIBs/Two Orbit User Test Week’ in February 2018. Results and user feedback will be discussed in this contribution. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3419 EP - 3422 KW - injection KW - resonance KW - electron KW - experiment KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THYYPLM2 UR - http://jacow.org/ipac2019/papers/thyyplm2.pdf ER -