Author: Arakawa, D.A.
Paper Title Page
MOPC155 Performance of the Micro-TCA Digital Feedback Board for DRFS Test at KEK-STF 445
 
  • T. Miura, D.A. Arakawa, S. Fukuda, E. Kako, H. Katagiri, T. Matsumoto, S. Michizono, Y. Yano
    KEK, Ibaraki, Japan
 
  The test of distributed RF scheme (DRFS) for ILC was carried out at the superconducting RF test facility in KEK (KEK-STF). The LLRF system and two klystron units were installed in the same tunnel as SRF cavities. The vector-sum control for two cavities was done by using the micro-TCA digital feedback board. This board was the same one developed for the compact-ERL at KEK, but the software was changed for pulse operation. The result of the performance will be reported.  
 
MOPC156 Operation Test of Distributed RF System with Circulator-less Waveguide Distribution in S1-Global Project at STF/KEK 448
 
  • T. Matsumoto, M. Akemoto, D.A. Arakawa, S. Fukuda, H. Honma, E. Kako, H. Katagiri, S. Matsumoto, H. Matsushita, S. Michizono, T. Miura, H. Nakajima, K. Nakao, T. Shidara, T. Takenaka, Y. Yano, M. Yoshida
    KEK, Ibaraki, Japan
 
  Distributed RF System (DRFS) is one candidate for a single main linac tunnel design of International International Linear Collider (ILC). In the DRFS, more than ten 800-kW klystrons having a modulating anode are operated by a common DC power and a modulation anode modulator. Each klystron feeds its power into two superconducting cavities and its waveguide distribution system is configured without circulators. This DRFS consists of four SC cavities, two klystrons and a modulator was demonstrated in S1-Global project. The results of circulator-less operation in the DRFS will be reported.  
 
MOPC157 Performance of LLRF System at S1-Global in KEK* 451
 
  • S. Michizono, D.A. Arakawa, S. Fukuda, E. Kako, H. Katagiri, T. Matsumoto, T. Miura, Y. Yano
    KEK, Ibaraki, Japan
 
  Vector-sum control was carried out at S1-Global. The rf stabilities of 0.007% in amplitude and 17 mdeg. in phase are obtained. Various diagnostics (such as on-line quench pulse detector, dynamic detuning monitor and so on) is implemented. The IF-mixture system, where 3 intermediate frequencies (IF) are used and the number of ADCs can be reduced, was used as rf waveform monitors. These monitors are used for the performance analysis. Quench phenomena observed at the high-gradient operation are also analyzed from the view point of dynamic change in loaded Q and cavity detuning during rf pulse.