Experimental Generation and Characterization of Uniformly Filled Ellipsoidal Beam Distribution

Recently, a scheme for producing ideal uniformly filled ellipsoidal beam distributions, which depends on the strong longitudinal expansion of an initially very short beam under its own space charge forces, has been demonstrated at the UCLA Pegasus Laboratory. Here we present further work on the characterization of this novel regime of operation of a photoinjector. In particular we study the sensitivity of the generation of the uniformly filled ellipsoidal distribution from the initial transverse laser profile. The ultra-high brightness of the beam created operating in this ‘blow-out’ regime is verified obtaining high quality relativistic electron diffraction patterns from thin Al foils.