MC7: Accelerator Technology
T24 Timing and Synchronization
Paper Title Page
THPRB033 Development Status of RF Reference Phase Stabilization System for SuperKEKB Injector LINAC 3879
 
  • N. Liu, B. Du
    Sokendai - Hayama, Hayama, Japan
  • D.A. Arakawa, H. Katagiri, T. Kobayashi, T. Matsumoto, S. Michizono, T. Miura, F. Qiu, Y. Yano
    KEK, Ibaraki, Japan
  • T. Matsumoto, T. Miura, F. Qiu
    Sokendai, Ibaraki, Japan
 
  SuperKEKB injector linear accelerator (LINAC) has 600 m beam lines which consist of 8 sectors. The 2856 MHz RF reference signals are distributed to each sector with long phase stabilized optical fiber (PSOF). The RF reference phase stability requirement is estimated to be 0.2°(RMS) corresponding to 200 fs. The prototype of RF reference phase stabilization system with single mode optical circulator was implemented and demonstrated in the laboratory. The returned phase drift is compensated by a piezo-driven fiber stretcher. The transmitted phase through 120 m PSOF is stabilized to 41 fs (pk-pk), which fulfilled the requirement. This paper introduces the RF reference phase stabilization system and reports the preliminary feedback result.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB033  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPRB045 A Novel Microwave Switch-Based LLRF System for Long-Term System Phase Drift Calibration 3915
 
  • Z.Y. Lin, Y.-C. Du, W.-H. Huang, C.-X. Tang, J. Tang
    TUB, Beijing, People’s Republic of China
  • G. Huang, Y.L. Xu
    LBNL, Berkeley, California, USA
  • Z. Sun, D. Zhang
    HZCY Technologies Co., Ltd., Beijing, People’s Republic of China
 
  The long-term phase drift is one of the important issue for the stability of the Low level RF system. The signal crosstalk and temperature effect on the RF field detectors will significantly limited the performance of the phase detecting precise and the phase locking. A novel micro-wave switch-based LLRF system has been developed in Tsinghua accelerator lab. The microwave switch are ap-plied to in the chopper circuit to turn continuous signal into pulse signal in the time domain to avoid the mutual signal interference. In this paper the LLRF system based on microwave switch is present. The preliminary long-term experiments result shows the phase stability can achieve about 50fs RMS slow drift; and the peak-to-peak value of the slow drift was (~2°C p-p) over 4 days.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB045  
About • paper received ※ 22 April 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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THPRB046 The Preliminary Long-Term Slow Drift Calibration Study in Low-Level Rf System 3918
 
  • Z.Y. Lin, Y.-C. Du, W.-H. Huang, C.-X. Tang, J. Tang
    TUB, Beijing, People’s Republic of China
  • G. Huang, Y.L. Xu
    LBNL, Berkeley, California, USA
  • Z. Sun, D. Zhang
    HZCY Technologies Co., Ltd., Beijing, People’s Republic of China
 
  The phase drift of the RF signal in the low-level radio frequency (LLRF) system is observed in the long-term operation, which limits the performance and stability of the LLRF system. The long-term drift was reproduced in the lab. Its effect and sources of error were explored in the simple LLRF46 board and the simplest LLRF system. It is founded that the temperature will significantly lead to the phase distortion of the two signal channels, although with the same electron device. The distortion will finally cause the long-term drift with temperature floating. A fixed phase calibration signal (CAL signal) is applied to deal with the signal channels difference. The preliminary tests were conducted and the results were analysed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB046  
About • paper received ※ 22 April 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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