A low emittance and uniform density Cs+ source for heavy ion induction linacs

Summary form only given, as follows. In a heavy-ion induction linac experiment (MBE-4) in progress at Lawrence Berkeley Laboratory, the transport and acceleration of space-charge-dominated beams in a long alternate gradient focusing channel are being studied. Recent studies of the transverse beam dynamics suggested that characteristics of the injector geometry were contributing to the normalized transverse emittance growth. Phase space and current density distribution measurements of the beam extracted from the injector revealed aberrations and a hollow density profile. Based on EGUN calculations, the 10-mA injector for MBE-4 was redesigned by modifying the cathode Pierce electrode and using a curved emitting surface. The simulation predicts an extracted beam with fewer aberrations and a flat density profile. A test stand was used to check the new design. The density profile was measured and found to be in agreement with the numerical simulation