Longitudinal injection transients in an electron storage ring

Abstract

We present the results of an experimental study of the longitudinal beam dynamics at injection in the advanced light source, an electron storage ring. By measuring the longitudinal bunch distribution following injection using a streak camera, we were able to study several useful and interesting effects as well as improve overall injection efficiency. These include measurement and correction of the phase and energy offsets at injection, measurement of the injected bunch length and energy spread, direct observation of phase space filamentation due to the spread in synchrotron frequencies, and measurement of the effective damping rate of the bunch shape including radiation damping and decoherence. We have also made some initial studies of the decay of an uncaptured beam at injection which may provide a novel means of measuring the radiation loss per turn.