• H.H. Li, J. Hou, B.C. Jiang, L.G. Liu, X.Y. Sun, S.Q. Tian, M.Z. Zhang, W.Z. Zhang
  SINAP, Shanghai

The SSRF (Shanghai Synchrotron Radiation Facility) storage ring consisting of 20 Double Bend Achromatic cells with four super-periods is designed with a low emittance of 3.9nm.rad on 3.5GeV beam energy. Commissioning of the storage ring began on Dec. 21st 2007, and the beam was stored within sixty hours. After one and a half years commissioning, all specifications of the storage ring were reached in 2009. In this paper, study of beam dynamics in the SSRF storage ring is presented. Results of the measurement are given in detail, such as model calibration, orbit stability, etc.

• I. Hwang, C. Kim, K.R. Kim, M. Kim, S.H. Nam, S.J. Park, S. Shin
  PAL, Pohang, Kyungbuk
• J. Hou, L.G. Liu
  SINAP, Shanghai

The measurement and the control of the coupling is essential to maximize synchrotron performance. Small coupling is required for small vertical size and high brightness. The Pohang Light Source has a 2.5 GeV storage ring and its coupling constant is measured as about 1%. In addition to errors at quadrupole or sextupole, the condition varying of the insertion device affects the coupling. The coupling for various condition is measured by the resonance and the response matrix and compared with the beam size and the lifetime. The correction and the control of the coupling is presented.

• G.X. Xia
  MPI-P, München
• B.C. Jiang
  SINAP, Shanghai
• L.G. Liu
  SSRF, Shanghai

Fast ion instability has been observed in the early commissioning and operation of the Shanghai Synchrotron Radiation Facility (SSRF) storage ring. In this paper, a weak-strong code is used to simulate the fast ion instability in SSRF storage ring. Various fill patterns and gas pressures are investigated. The results show that the mini-train fill patterns are very effective to suppress the growth of the fast ion instability. By employing a fast feedback system, it is possible to damp the growth of beam oscillation amplitude below the beam size.