Observation and simulation of space-charge effects in a radio-frequency photoinjector using a transverse multibeamlet distribution

Abstract

We report on an experimental study of space-charge effects in a radio-frequency (rf) photoinjector. A 5 MeV electron bunch, consisting of a number of beamlets separated transversely, was generated in an rf photocathode gun and propagated in the succeeding drift space. The collective interaction of these beamlets was studied for different experimental conditions. The experiment allowed the exploration of space-charge effects and its comparison with 3D particle-in-cell simulations. Our observations also suggest the possible use of a multibeam configuration to tailor the transverse distribution of an electron beam.