A normalized detector of beam transverse oscillations

Abstract

This beam detector accepts the narrow pulses typically encountered in electron storage rings. It is composed of a peak detector with a threshold held constant by means of an automatic gain control (AGC) loop, and of a sampler. The output is proportional to the instantaneous position of the beam center of charge and is independent of the beam current. In addition, the very small phase shift of the AGC attenuator allows the use of the undetected, constant amplitude pulse as a trigger for time of flight measurements, with a remarkably small time slewing over a 30 to 1 beam current range.