Author: Liu, M.
Paper Title Page
Femtosecond Timing System Development in SSRF  
  • X.L. Dai, M. Liu, C.X. Yin, L.Y. Zhao
    SINAP, Shanghai, People's Republic of China
  Funding: The project of femtosecond timing system was supported by the National Natural Science Foundation of China (No. 11305246).
The current timing system in SSRF cannot satisfy the requirement of the pump-probe experiment in SSRF Phase-II project, so the femtosecond timing system was developed to realize 100fs jitter and 200fs phase drift in the long term. The femtosecond timing system is based on optical fiber networks and laser frequency stabilizing system. To achieve less than 100fs jitter, the narrow line-width Continues Wave (CW) laser is used to transmit RF signals in optical fiber networks. In order to achieve less than 200fs phase drift in the long term, the phase change in the optical fiber networks is detected by heterodyne interferometer and compensated by LLRF system to generate timing signals. The design and preliminary test result of femtosecond timing system is presented in this paper.
slides icon Slides WEC3O03 [30.829 MB]  
WEC3O04 New Event Timing System for Damping Ring at SuperKEKB 1
  • H. Kaji, K. Furukawa, M. Iwasaki, T. Kobayashi, F. Miyahara, T.T. Nakamura, M. Satoh, M. Suetake, M. Tobiyama
    KEK, Ibaraki, Japan
  • Y. Iitsuka
    EJIT, Hitachi, Ibaraki, Japan
  • T. Kudou, S. Kusano
    Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
  • M. Liu, C.X. Yin
    SINAP, Shanghai, People's Republic of China
  SuperKEKB is the upgrade of KEKB, which is the world's largest luminosity accelerator at KEK. One of key items to realize 40 times larger luminosity than that of KEKB is damping ring (DR) for positron injection. The injector linac (LINAC) once stores the produced positrons into DR and suppress their emittance. Then low emittance positrons are extracted from DR and injected into the main ring. For this complicated injection process, the Event Timing System* for LINAC** was upgraded and its soundness is demonstrated by injecting electrons into two light source rings***. New Event modules were also installed under the Event network for LINAC as the sub timing system for DR. New Event modules were developed which can be operated with the different Event clock from that of upstream modules. It solves the difference in RF frequency between LINAC (2856MHz) and DR (509MHz). This sub timing system can manage the triggers towards totally 84 BPMs at DR although it consists of only 5 Event modules. The timing of those triggers can be independently set in more precise than 100ps. The requirements to DR timing system and the newly developed modules with its configuration at DR are explained.
*H. Kaji et al., THCOCA04, Proc. of ICALEPCS'13, San Francisco, CA.**H. Kaji et al., TUPRI109, Proc. of IPAC'14, Dresden, Germany.***Abstract submitted to IPAC'15.
slides icon Slides WEC3O04 [1.496 MB]