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MOPO102 Progress of MicroTCA.4 based LLRF System of TARLA 220
 
  • C. Gumus, M. Hierholzer, H. Schlarb, Ch. Schmidt
    DESY, Hamburg, Germany
  • A.A. Aksoy, A. Aydin, Ç. Kaya
    Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
  • O.F. Elcim
    Ankara University Institute of Accelerator Technologies, Golbasi, Turkey
 
  The Turkish Accelerator and Radiation Laboratory in Ankara (TARLA) is constructing a 40 MeV Free Electron Laser with continuous wave RF operation. DESY is responsible for delivering a turnkey LLRF system based on MicroTCA.4 standard that will be used to control four superconducting (SC) TESLA type cavities as well as the two normal conducting buncher cavities. This highly modular system is further used to control the mechanical tuning of the SC cavities by control of piezo actuators and mechanical motor tuners. With the usage of ChimeraTK framework, integration to EPICS control system is also implemented. This poster describes the system setup and integration to the existing accelerator environment with hardware and software components along with the latest updates from the facility.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO102  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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MOPO104 LLRF R&D Towards CW Operation of the European XFEL 223
SPWR026   use link to see paper's listing under its alternate paper code  
 
  • A. Bellandi, V. Ayvazyan, J. Branlard, C. Gumus, S. Pfeiffer, K.P. Przygoda, R. Rybaniec, H. Schlarb, Ch. Schmidt, J.K. Sekutowicz
    DESY, Hamburg, Germany
  • W. Cichalewski
    TUL-DMCS, Łódź, Poland
 
  The ever growing request for machines with a higher average beam pulse rate and also with a relaxed (< 1 MHz) pulse separation calls for superconducting linacs that operate in Long Pulse (LP) or Continuous Wave (CW) mode. For this purpose the European X-ray Free Electron Laser (European XFEL) could be upgraded to add the ability to run in CW/LP mode. Cryo Module Test Bench (CMTB) is a facility used to perform tests on superconducting cavity cryomodules. Because of the interest in upgrading European XFEL to a CW machine, CMTB is now used to perform studies on XM-3, a 1.3 GHz European XFEL-like cryomodule with modified coupling that is able to run with very high quality factor (QL = 10E7…10E8) values. The RF power source allows running the cavities at gradients larger than 16 MV/m. Because of the QL and gradient values involved in these tests, detuning effects like mechanical resonances and microphonics became more challenging to regulate. The goal is then to determine the appropriate set of parameters for the LLRF control system to keep the error to be less than 0.01° in phase and 0.01% in amplitude.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO104  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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MOPO106 New Digital LLRF System for HIT 227
 
  • E. Feldmeier, Th. Haberer, A. Peters
    HIT, Heidelberg, Germany
 
  The Heidelberg Ion Therapy Center HIT is in clinical operation since 2009. The accelerator complex consists of a linear accelerator and a synchrotron to provide carbon ions and protons for clinical use as well as helium and oxygen ions. The analog LLRF system for the linac should be replaced after more than 10 years of continuous operation. In its life-time the LLRF caused no interruption of the clinical operation with a downtime of more than 15 minutes. In order to keep the reliability in the next 10 years at least as high, a new digital LLRF system is planned. Further difficulties for the installation of a new system are due to the clinical full time usage of the accelerator and the short maintenance slots of only two days in series.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO106  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO107 Performance Evaluation of the RF Reference Phase Stabilization System on Fiber-optical Link for KEK e/e+ Injector LINAC 230
SPWR027   use link to see paper's listing under its alternate paper code  
 
  • N. Liu, B. Du
    Sokendai - Hayama, Hayama, Japan
  • D.A. Arakawa, H. Katagiri, T. Matsumoto, S. Michizono, T. Miura, F. Qiu, Y. Yano
    KEK, Ibaraki, Japan
  • T. Matsumoto, T. Miura, F. Qiu
    Sokendai, Ibaraki, Japan
 
  KEK e/e+ injector is the 600 m J-shaped LINAC which has 8 RF sectors. Stabilization of RF phase reference for long distance transmission is necessary for stable RF operation. In the present system, single-mode fiber-optical links without feedback control are used from sector 2 to 5. For the SuperKEKB, the phase stability requirement is within 0.1 deg. rms. The more stable RF phase reference is necessary to improve the phase stability. In this paper, a feedback control system for RF reference phase stabilization is tested for system performance evaluation. The temperature and humidity characteristics of the electric and optical components and phase stabilized optical fiber (PSOF) with different wavelengths will also be presented.  
poster icon Poster MOPO107 [2.026 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO107  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO111 Development of New LLRF System at the J-PARC Linac 233
 
  • K. Futatsukawa, Z. Fang, Y. Fukui
    KEK, Ibaraki, Japan
  • Y. Sato
    Nippon Advanced Technology Co., Ltd., Tokai, Japan
  • S. Shinozaki
    JAEA/J-PARC, Tokai-mura, Japan
 
  In the J-PARC linac, the LLRF system with the digital feedback (DFB) and the digital feedforward (DFF) was adopted for satisfying requirement of amplitude and phase stabilities. It has been operated without serious problems. However, it has been used since the beginning of the J-PARC and more than ten years have already passed since the development. The increase of the failure frequency for this system is expected. Additionally, it is difficult to maintain it for some discontinued boards of DFB and DFF and the older developing environment of software. Therefore, we are starting to study the new LLRF system of the next generation. In the present, we are exploring several possibilities of a new way and investigating each advantage and disadvantage. The project and the status of the development for the new system in the J-PARC linac LLRF are introduced.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO111  
About • paper received ※ 22 September 2018      issue date ※ 18 January 2019  
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MOPO115 CEBAF Photo Gun RF System 236
 
  • T. E. Plawski, R. Bachimanchi, M. Diaz, H. Higgins, C. Hovater, C.I. Mounts, D.J. Seidman
    JLab, Newport News, Virgina, USA
 
  Funding: Authored by JSA, LLC under U.S. DOE Contract DE-AC05- 06OR23177 and DE-SC0005264.
During the CEBAF 12 GeV Upgrade at Jefferson Lab, a fourth experimental hall, ’D’, was added to the existing three halls. To produce four beams and deliver them to all halls concurrently requires new frequencies and a new timing pattern of the electron bunches. Since a photo-gun is used to produce electron bunches, the gun’s drive laser pulses need to be synchronized with the required bunch rate frequencies of 499 MHz or 249.5 MHz. To meet these new operational requirements, the new LLRF system has been proposed. Very specific requirements (dual frequency operation) on one side and the simple RF drive mode operation on the other imply the use of a commercial off-the-shelf digital platform rather than a system typical for RF cavity field control. We have chosen the Texas Instruments FPGA board along with a high-speed 8-Channel, 14-Bit board, and a 4-Channel, 16-Bit board. The DAC board includes the clock generator for clocking ADCs, DACs and the FPGA. The complete Gun Laser LLRF system has been designed, built, and recently commissioned in the CEBAF Injector. This paper will detail the design and report on commissioning activities.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO115  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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