An analysis of longitudinal phase space fragmentation at the TESLA test facility

It has been repeatedly observed, at TTF-FEL, that the energy profile of the fully longitudinally compressed beam breaks up into peaks. In this paper we analyze a potential cause of this effect. We study the bunch self-interaction via coherent synchrotron radiation, leading to a fragmentation of the longitudinal phase space. For our analysis, we use a simple model as well as the simulation code TraFiC4 (Nucl. Instr. and Meth. A 445 (2000) 338) to evaluate the CSR-induced effects.