TY - CONF AU - Stoll, C.P. AU - Hug, F. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Beam Breakup Simulations for the Mainz Energy Recovering Superconducting Accelerator MESA J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - MESA is a two pass energy recovery linac (ERL) currently under construction at the Johannes Gutenberg-University in Mainz. MESA uses four 1.3 GHz TESLA type cavities with 12.5 MV/m of accelerating gradient in two modified ELBE type cryomodule with improved thermal connection of the HOM antennas and cw operation. In the first stage of MESA operation 1mA of beam current is foreseen, which will later be upgraded to 10mA. One potential limit to maximum beam current in ERLs is the transverse beam breakup (BBU) instability induced by dipole Higher Order Modes (HOMs). These modes can be excited by bunches passing through the cavities off axis. Following bunches are then deflected by the HOMs, which results in even larger offsets for recirculated bunches. This feedback can even lead to beam loss. Simulation results for HOM spectra of a single TESLA cavity are available for example in *. It was possible to measure the HOM spectra in the cold, not tuned cavities at DESY and in the cold string tuned to the 1.3 GHz fundamental mode at Mainz. Results for the maximum beam current for MESA, limited by BBU, for the various HOM spectra are presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 135 EP - 138 KW - cavity KW - HOM KW - cryomodule KW - simulation KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPGW025 UR - http://jacow.org/ipac2019/papers/mopgw025.pdf ER - TY - CONF AU - Schwarz, M. AU - Aulenbacher, K. AU - Barth, W.A. AU - Basten, M. AU - Burandt, C. AU - Busch, M. AU - Conrad, T. AU - Dziuba, F.D. AU - Gettmann, V. AU - Heilmann, M. AU - Kürzeder, T. AU - Lauber, S. AU - List, J. AU - Miski-Oglu, M. AU - Podlech, H. AU - Rubin, A. AU - Yaramyshev, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Advanced Beam Dynamics Design for the Superconducting Heavy Ion Accelerator HELIAC J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The standalone superconducting (SC) continuous wave (CW) heavy ion linac HELIAC (HElmholtz LInear ACcelerator) is a common project of GSI and HIM under key support of IAP Frankfurt and in collaboration with Moscow Engineering Physics Institute (MEPhI) and Moscow Institute for Theoretical and Experimental Physics (KI-ITEP). It is intended for future experiments with heavy ions near the Coulomb barrier within super-heavy element (SHE) research and aims at developing a linac with multiple CH cavities as key components downstream the High Charge State Injector (HLI) at GSI. The design is challenging due to the requirement of intense beams in CW mode up to a mass-to-charge ratio of 6, while covering a broad output energy range from 3.5 to 7.3 MeV/u with minimum energy spread. In 2017 the first superconducting section of the linac has been successfully commissioned and extensively tested with beam at GSI. In the light of experience gained in this research so far, the beam dynamics layout for the entire linac has recently been updated and optimized with particular emphasis on realistic assumptions of cavity gap and drift lengths as well as gap voltage distributions for CH3’CH11. PB - JACoW Publishing CP - Geneva, Switzerland SP - 928 EP - 931 KW - cavity KW - linac KW - heavy-ion KW - SRF KW - acceleration DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-MOPTS034 UR - http://jacow.org/ipac2019/papers/mopts034.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 - Dziuba, F.D. AU - Aulenbacher, K. AU - Barth, W.A. AU - Basten, M. AU - Burandt, C. AU - Busch, M. AU - Conrad, T. AU - Gettmann, V. AU - Heilmann, M. AU - Kürzeder, T. AU - Lauber, S. AU - List, J. AU - Miski-Oglu, M. AU - Podlech, H. AU - Salvatore, J. AU - Schnase, A. AU - Schwarz, M. AU - Yaramyshev, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Further RF Measurements on the Superconducting 217 MHz CH Demonstrator Cavity for a CW Linac at GSI J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - Recently, the first section of the superconducting (sc) continuous wave (cw) Linac has been extensively tested with heavy ion beam from the GSI High Charge State Injector (HLI). During this testing phase, the reliable operability of 217 MHz multi gap crossbar-H-mode (CH) cavities has been successfully demonstrated. The sc 217 MHz CH cavity (CH⁰) of the demonstrator setup accelerated heavy ions up to the design beam energy and even beyond at high beam intensities and full transmission. This worldwide first beam test with a sc CH cavity is a major milestone on the way realizing the entire sc cw Linac project. In this contribution further RF measurements on the cavity are presented providing full characterization of the RF structure. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2826 EP - 2829 KW - cavity KW - linac KW - heavy-ion KW - MMI KW - operation DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB014 UR - http://jacow.org/ipac2019/papers/weprb014.pdf ER - TY - CONF AU - Kürzeder, T. AU - Aulenbacher, K. AU - Barth, W.A. AU - Burandt, C. AU - Conrad, J. AU - Dziuba, F.D. AU - Gettmann, V. AU - Heine, R.G. AU - Hug, F. AU - Lauber, S. AU - List, J. AU - Miski-Oglu, M. AU - Stengler, T. AU - Yaramyshev, S. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Cleanroom Installations for SRF Cavities at the Helmholtz-Institut Mainz J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - At the Helmholtz-Institut Mainz (HIM) a cleanroom has been equipped with new tools and installations for the planned treatment of different superconducting RF-cavities. At first TESLA/XFEL type 9-cell cavities for the Mainz Energy-Recovering Superconducting Accelerator (MESA) project or 217 MHz multigap Crossbar H-mode cavities for the HElmholtz LInear ACcelerator (HELIAC) under development by HIM and GSI will be treated. The cleanroom installations, including the greyroom, cover an area of about 155 sqm. In its ISO-class 6 area a large ultrasonic and a conductance rinsing bath has been installed recently. A high pressure rinsing cabinet (HPR) has been implemented between the ISO-class 6 and 4 cleanroom. A RF-cavity can be loaded and unloaded from both sides. HPR treatments are possible for cavities of up to 1.4 m length and about 0.7 m diameter. For drying the ISO-class 4 clean room is equipped with a 160 C vacuum oven. New cleanroom lifters allow the handling of up to 200 kg heavy objects. A rail system in the cleanroom floor is installed to move out the entire cold string of the cleanroom after assembly and leak testing. First operational experiences with this facility will be presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 2830 EP - 2833 KW - cavity KW - operation KW - vacuum KW - heavy-ion KW - SRF DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-WEPRB015 UR - http://jacow.org/ipac2019/papers/weprb015.pdf ER - TY - CONF AU - Ledroit, B. AU - Aulenbacher, K. ED - Boland, Mark ED - Tanaka, Hitoshi ED - Button, David ED - Dowd, Rohan ED - Schaa, Volker RW ED - Tan, Eugene TI - Collimation of Target Induced Halo Following MAGIX at MESA J2 - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019 CY - Melbourne, Australia T2 - International Particle Accelerator Conference T3 - 10 LA - english AB - The Mainz Energy-recovering Superconducting Accelerator (MESA) will be an electron accelerator allowing operation in energy-recovery linac (ERL) mode. It provides the opportunity to operate scattering experiments at energies of ~100 MeV with thin gas-targets. The MESA Internal Gas Target Experiment (MAGIX) aims to operate windowless jet targets and different gases up to Xenon to search for possible dark photon interactions, to precisely measure the magnetic proton radius and astrophysical S-factors. Investigations on the impact of the target on beam dynamics and beam losses are required for machine safety and to examine limits to ERL operation. The goal of this work is to understand target induced halo in the different experimental setups, track halo particles through downstream sections to examine beam losses and include a suitable collimation system and shielding into the accelerator layout to protect the machine from direct and indirect damage through beam losses and radiation. The present status of the investigations is presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 3839 EP - 3842 KW - target KW - simulation KW - beam-losses KW - experiment KW - cryomodule DA - 2019/06 PY - 2019 SN - 978-3-95450-208-0 DO - DOI: 10.18429/JACoW-IPAC2019-THPRB019 UR - http://jacow.org/ipac2019/papers/thprb019.pdf ER -