• J.H. Wang, Y.B. Chen, W. Li, L. Liu, M. Meng, B. Sun, L. Wang, Y.L. Yang, Z.R. Zhou
  USTC/NSRL, Hefei, Anhui
• J. Cao, J. Yue
  IHEP Beiing, Beijing
• D.K. Liu
  SINAP, Shanghai
• L. Ma
  IHEP Beijing, Beijing
• K.R. Ye
  SSRF, Shanghai

In this paper, we introduce the BxB transverse feedback systems at Hefei Light Source (HLS), which employ an analog system and a digital system. The construction and commissioning for two feedback systems, as well as the instability analysis of beam and the experiment result of the feedback system in HLS are also presented in this paper.

• D. Teytelman
  Dimtel, San Jose
• J.M. Byrd
  LBNL, Berkeley, California
• J. Cao, J. Yue
  IHEP Beijing, Beijing

BEPC-II is a two ring electron-positron collider designed to operate at 1 A beam currents. Longitudinal and transverse coupled-bunch instabilities have been observed in both electron and positron rings. In this paper we present measurements of both transverse and longitudinal instabilities with the identification of active eigenmodes, measurements of growth and damping rates, as well as of the residual beam motion levels. The measurements will then be used to estimate the growth rates at the design beam currents (yet to be achieved). We will also demonstrate how such data is used for specifying power amplifier and kicker parameters.