Studies of positional stability of the electron beam in the NSLS storage ring

Positional stability of the electron beam is critically important to experimental beam line users. The beam position vibration increases the effective beam size and thus reduces the brightness. So the potential stability measurement provides important information for beam lines. Data about amplitude and frequency of beam vibration and long term beam movement at different beam ports can be useful in locating the noise source for accelerator physicists. For the noise which cannot be eliminated, a beam position monitor can provide the signal for the feedback system to stabilize the beam position. These consideration become more evident as higher brightness and better energy resolution are sought. In this paper the authors report a preliminary result of the beam position stability measurement at the NSLS