Author: Ebihara, K.
Paper Title Page
WEPPP090 Stable RF Distribution System for the S-band Linac 2924
  • T. Naito, K. Ebihara, S. Nozawa, N. Terunuma, J. Urakawa
    KEK, Ibaraki, Japan
  • M. Amemiya
    AIST, Tsukuba, Japan
  The phase stabilization of the RF phase is key issue for the stable linac operation. An RF distribution system with femto-second stability has been developed for S-band linac using optic fiber links. The system uses a phase stabilized optical fiber (PSOF) and an active fiber length stabilization.* The phase stability is 0.1 degree (100f s) for 24 hours observation. In this paper, we present the test results of the system stability and evaluation of the existing RF reference line by using this system.
* Naito et. al. IPAC10 MOPC146
THPPC079 Prototype Performance of Digital LLRF Control System for SuperKEKB 3470
  • T. Kobayashi, K. Akai, K. Ebihara, A. Kabe, K. Nakanishi, M. Nishiwaki, J.-I. Odagiri
    KEK, Ibaraki, Japan
  • H. Deguchi, K. Harumatsu, K. Hayashi, J. Nishio, M. Ryoshi
    Mitsubishi Electric TOKKI Systems, Amagasaki, Hyogo, Japan
  For the SuperKEKB project, a new LLRF control system has been developed to realize high accuracy and flexibility. It is an FPGA-based digital RF feedback control system using 16-bit ADC's, which works on the μTCA platform. In this μTCA-module, the Linux-OS runs then it performs as the EPICS-IOC. This LLRF system is available to both of normal-conducting cavity and super-conducting cavity. A prototype of the LLRF control system for the SuperKEKB was produced. The feedback control stability, temperature characteristics and cavity-tuner control performance are evaluated. The evaluation results and future issue for the operation will be presented in this report. The amplitude and phase stability in the feedback control is 0.03% and 0.02 degrees, respectively. It is sufficiently stable for the SuperKEKB. However, the temperature dependency is not small for the required stability. Its countermeasures are under consideration.