Experiments on a 14.5 GHz ECR source

The 14.5 GHz ECR4 source supplied to CERN in the framework of the Heavy Ion Facility collaboration provided Pb27+ operational beams to a new custom built linac in 1994. This source, which operates in the pulsed "afterglow" mode, quickly met its design specification of 80 emA and now provides currents >100 emA regularly. Early source tests showed the existence of extremely stable modes of operation. In the search for higher intensities a number of experiments have been performed on plasma gas composition, RF power matching, extraction, beam pulse compression and a biased dynode. The results of these tests will be presented along with further ideas to improve source performance