• O. Singh, I. Pinayev
  BNL, Upton, Long Island, New York
• G. Decker, B.X. Yang
  ANL, Argonne, Illinois

Sub-micron beam stability is a necessary performance requirement for the NSLS II light source, a substantial challenge testing the limits for presently available RF beam position monitoring methods. Direct performance comparisons between commercially available bpms and Advanced Photon Source in-house developed bpm were made at the APS Storage Ring. Noise floor, fill pattern dependence, and intensity dependence were investigated and correlated with photon diagnostics at the beam diagnostic beamline at APS sector 35. Key results will be presented.