Author: Gu, M.
Paper Title Page
MOPFI046 Transverse RF Kicker Excitation and Longitudinal RF Noise Diffusion for Slow Extraction from SAPT 386
 
  • L. Ouyang, M. Gu, D.M. Li, Q. Yuan, M.Z. Zhang
    SINAP, Shanghai, People's Republic of China
 
  Two key techniques used in the slow extraction from synchrotron accelerator: longitudinal RF stochastic noise acceleration, and transverse RF knock out excitation have been studied in this paper. Detailed comparison have revealed the potentials and limits of both methods. For the longitudinal RF stochastic acceleration excitation, the focus has been the phase space compression of particles, which makes the them to hasten around the RF bucket of the cavity, thus to lower the senstivity to ripple. For the transverse RF knock out excitation, the emphasis have been optimal schemes of amplitude modulation and frequency modulation of the RF singals. The optimizations are also used to lower the senstivity of the beam to the ripple and to enhance the uniformity of the extracted beam.  
 
WEPWA032 The Feed-forward Control Design of Correction Coil Power Supply for SSRF EPU 2199
 
  • Q. Yuan, M. Gu, G.Y. Jiang, R. Wang
    SINAP, Shanghai, People's Republic of China
 
  The SSRF Elliptically Polarized Undulator (EPU) has been in operation for about three years. The feed-forward control algorithm of correction coil power supply (CCPS) is implemented in the Input and Output Controller (IOC) based on VME. The correction current responds not fast enough to gap movement, mainly because the communication between IOC and digital CCPS taking up much time. This paper introduces one new feed-forward design, that is ,on the one hand, the CCPS current responds to both gap movement and shift movement according to 2D Look-up Table(LUT) by linear interpolation method. On the other hand, feed-forward control algorithm is carried out in the EPU controller, and the CCPS with fast control response is directly controlled by PLC through analog interface. Thus, the correction current respond well to gap and shift movement owing to leaving out communication time.