Keyword: controls
Paper Title Other Keywords Page
TUCOZBS04 Characterization of Microphonics in the cERL Main Linac Superconducting Cavities cavity, LLRF, operation, linac 48
 
  • F. Qiu, D.A. Arakawa, M. Egi, E. Kako, H. Katagiri, T. Konomi, T. Matsumoto, S. Michizono, T. Miura, H. Sakai, K. Umemori
    KEK, Ibaraki, Japan
  • M. Egi, S. Michizono
    Sokendai - Hayama, Hayama, Japan
  • E. Kako, T. Konomi, T. Matsumoto, T. Miura, F. Qiu, H. Sakai, K. Umemori
    Sokendai, Ibaraki, Japan
 
  In the main linac (ML) of the KEK-cERL, two superconducting cavities with high loaded Q (QL ¿ 1×107) are operated in continuous wave (CW) mode. It is important to control and suppress the microphonics detuning owing to the low bandwidth of the cavities. We evaluated the background microphonics detuning by the low level radio frequency system during the beam operation. Interestingly, a ¿field level dependence microphonics¿ phenomenon was observed on one of the cavities in the ML. Several frequency components were suddenly excited if the cavity field is above a threshold field (~3 MV/m). We found that this threshold field is probably related with the cavity quench limits despite the unclear inherent physical mechanism. Furthermore, in order to optimize the cavity resonance control system for better microphonics rejection, we have measured the mechanical transfer function between the fast piezo tuner and cavity detuning. Finally, we validated this model by comparing the model response with actual system response.  
slides icon Slides TUCOZBS04 [7.564 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-TUCOZBS04  
About • paper received ※ 13 September 2019       paper accepted ※ 01 November 2019       issue date ※ 24 June 2020  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUCOZBS05 Low Level RF ERL Experience at the S-DALINAC* cavity, operation, beam-loading, linac 52
 
  • M. Steinhorst, M. Arnold, T. Bahlo, R. Grewe, L.E. Jürgensen, J. Pforr, N. Pietralla, F. Schließmann, S. Weih
    TU Darmstadt, Darmstadt, Germany
 
  Funding: *Supported by the DFG through GRK 2128.
The recirculating superconducting Darmstadt linear accelerator S-DALINAC [1] is one of the main research instruments at the institute for nuclear physics at the TU Darmstadt. It is operating in cw mode at beam currents of up to 20 uA with energies of up to 130 MeV using a thrice recirculating scheme. In 2010 the present digital low-level rf (LLRF) control system was set into operation. Since 2017 the S-DALINAC can be used as an energy recovery linac (ERL). The ERL mode is adjusted by shifting the phase of the beam by 180° in the second recirculation. The current setup of the LLRF control system is not optimized for the usage in an ERL operation. Therefore investigations in regard of the rf control performance have to be done. The first successful one turn ERL operation was set up in August 2017 where the rf control performance was investigated the first time in this new mode. In this talk the LLRF control system of the S-DALINAC is presented and its perfomance during an ERL operation is discussed.
*[1] N. Pietralla, Nucl. Phys. News 28 No. 2, 4 (2018).
 
slides icon Slides TUCOZBS05 [26.760 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-TUCOZBS05  
About • paper received ※ 13 September 2019       paper accepted ※ 01 November 2019       issue date ※ 24 June 2020  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THCOWBS03 System Identification Procedures for Resonance Frequency Control of SC Cavities operation, simulation, cryomodule, linac 129
 
  • S. Orth, H. Klingbeil
    TEMF, TU Darmstadt, Darmstadt, Germany
 
  Funding: Work supported by Deutsche Forschungsgemeinschaft (DFG): GRK 2128 ’AccelencE’
Energy Recovery Linacs promise superior beam quality: sharper and more intense. To reach these goals, resonance frequency control of the superconducting RF cavities is an important part. In this work, system identification procedures conducted at components of the S-DALINAC (Institute for Nuclear Physics, TU Darmstadt, Germany) are shown. This includes investigations of the piezo tuner’s effect on, e.g., the phase of the accelerating field when a periodic disturbance is applied. The results are compared to simulations of the modelled system and the impact of the applied controller is discussed.
 
slides icon Slides THCOWBS03 [0.593 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-THCOWBS03  
About • paper received ※ 17 September 2019       paper accepted ※ 01 November 2019       issue date ※ 24 June 2020  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
FRCOXBS04 Status of the Control System for the Energy Recovery Linac BERLinPro at HZB EPICS, laser, operation, linac 159
 
  • T. Birke, P. Echevarria, D. Eichel, R. Fleischhauer, J.G. Hwang, G. Klemz, R. Müller, C. Schröder, E. Suljoti, A. Ushakov
    HZB, Berlin, Germany
 
  BERLinPro is an energy recovery linac (ERL) demonstrator project built at HZB. It features CW SRF technology for the low emittance, high brightness gun, the booster module and the recovery linac. Construction and civil engineering are mostly completed. Synchronized with the device integration the EPICS based control system is being set-up for testing, commissioning and finally operation. In the warm part of the accelerator technology is used that is already operational at BESSY and MLS (e.g. CAN-bus and PLC/OPCUA). New implementations like the machine protection system and novel major subsystems (e.g. LLRF, Cryo-Controls, photo cathode laser) need to be integrated. The first RF transmitters have been tested and commissioned. Around the time of this workshop the first segment of the accelerator is scheduled to become online. For commissioning and operation of the facility the standard set of EPICS tools form the back-bone. A set of generic python applications already developed at BESSY/MLS will be adapted to the specifics of BERLinPro. Scope and current project status are described in this paper.  
slides icon Slides FRCOXBS04 [11.021 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-FRCOXBS04  
About • paper received ※ 05 September 2019       paper accepted ※ 11 November 2019       issue date ※ 24 June 2020  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
FRCOYBS04 Working Group Summary: Superconducting RF cavity, HOM, operation, cryomodule 177
 
  • F. Gerigk
    CERN, Meyrin, Switzerland
  • P.A. McIntosh
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  To be added  
slides icon Slides FRCOYBS04 [17.955 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ERL2019-FRCOYBS04  
About • paper received ※ 20 September 2019       paper accepted ※ 01 November 2019       issue date ※ 24 June 2020  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)