IMPACT OF FILLING PATTERNS ON BUNCH LENGTH AND LIFETIME AT THE SLS

The filling pattern can impact in the effective bunch lengthening of a passive 3rd harmonic system and, as a consequence, the Touschek component of the beam lifetime. Using a longitudinal dynamics tracking code, in which the effects of the accelerating system and the 3rd harmonic system are taken into account, we can calculate the synchronous phase drift caused by the transient beam-loading and thus the effective bunch increase for several different filling patterns. In this note we present a comparison between simulation and measurements for the SLS.