Studies of Positional Stability of the Electron Beam in the NSLS Storage Ring

The beam position monitor used at NSLS is described, with a resolution of 1 ..mu..m without considering mirror vibration. An upper limit of the resolution is 11 ..mu..m, given by a preliminary measurement of mirror angular vibration. Further improvement of this measurement can lower the upper limit. Preliminary result of long term beam movement and vibration of beam position is reported. These measurements are correlated with ambient and controlled mechanical vibration of a quadrupole. The 60 Hz vibration seems unlikely to be caused by quadrupole mechanical vibration, but 12 Hz beam vibration can be accounted for by this vibration. In time, correlation with ambient and controlled electrical variation will be measured. These measurements and more efforts on monitors at other beam ports to locate noise source are under way.