A Brighter H- Source for the Intense Pulsed Neutron Source Accelerator System

Further increases in the beam intensity of the Intense Pulsed Neutron Source (IPNS) at Argonne National Labortory required the replacement of the H- source with a higher current source. A magnetron ion source of Fermi National Accelerator Laboratory (FNAL) design was adapted with a grooved cathode to provide a stable 40-50 mA of beam operating at 30 Hz for up to a 90 ¿s pulse duration. Problems of space charge blowup due to the lack of neutralization of the H- beam were solved by injecting additional gas into the 20 keV transport system. The source has recently been installed in the machine and the available input to the accelerator has more than doubled.