Nsls-ii beam aperture slit vibration studies

Beam aperture slits mounted on stepper-motor driven X-Y stages are used in NSLS-II frontends to define the beam size and to limit thermal loads on downstream optical components. The X-Y stages have positional and resolution requirements of 1 μm and 0.1 μm, respectively. This is achieved by micro-stepping the stepper motor by a Delta-Tau GeoBrick-LV-NSLS-II controller. During the initial operation of the X-Y stages unacceptable levels of vibration when the stages were in motion, and an intermittent sharp squealing when they were at rest, were discovered. In this paper we present the studies that were undertaken to investigate these issues and the solutions that were implemented.