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Lee, E.-H.

Paper Title Page
MPPP003 FALSE BPM READINGS AFFECTING ORBIT FEEDBACK 847
 
  • H.-S. Kang, J. Choi, M.-H. Chun, K.M. Ha, J.Y. Huang, Y.-C. Kim, E.-H. Lee, T.-Y. Lee, W.W. Lee, J.-H. Suh
    PAL, Pohang, Kyungbuk
  
  Funding: Ministry of Science and Technology, Korea.

A slow global orbit feedback (SOFB) is routinely operating in the usual user service operation at PLS. The orbit feedback uses 22 correctors in each plane which have 20-bit capability for the vertical plane and 16-bit capability for the horizontal plane, and the feedback speed is 4 seconds. The orbit stability in RMS was maintained below 1 mm in both planes for one hour and 3 mm for a 12-hour operation. The BPM chamber movement due to the change of synchrotron radiation heat load mainly limits the SOFB performance. The intensity dependence of BPM electronics is well compensated by a look-up table of BPM.

 
RPAE046 Operational Status at the PLS: Recent Improvements and Changes 2923
 
  • E.S. Park, J. Choi, H.-S. Kang, M. Kim, E.-H. Lee, T.-Y. Lee
    PAL, Pohang, Kyungbuk
  
  PLS has been operated 10 years since 1994. A few improvements has been made to stabilize the reference orbit drifts caused by insertion devices and other sources: The control system has been upgraded to 20 bit capability from 12 bit. The slow global orbit feedback is employed routinely in the user run times. These improvements and the operational status changes will be presented in this report.