Wakefield measurement using principal component analysis on bunch-by-bunch information during transient state of injection in a storage ring

Abstract

Wakefields and beam instabilities are important issues for a storage ring and are described by various theoretical formalisms. Direct measurements of the beam motion related to different dynamical mechanisms are a useful input to accelerator optimization. This paper reports on an experimental method based on a simplified wakefield model, where bunch-by-bunch position information were monitored during the transient injection process at the Shanghai Synchrotron Radiation Facility. Processing the bunch-by-bunch data by means of the principal component analysis allowed for immediate operational improvements---such as in situ compensation of the kicker leakage, and energy matching between the booster and the storage ring.