An Intense H- Source for the IPNS-I Rapid Cycling Synchrotron

Increases in the intensity of the Intense Pulsed Neutron Source (IPNS-I) at Argonne National Laboratory will eventually require that the present H- ion source be replaced with a higher current source. Laboratory studies of a Penning H- ion source for this purpose have been carried out. The source design is essentially due to Allison.1 The source has operated continuously for more than a week at 15 Hz with 45 mA of H- current during the 80 ¿s pulse. For shorter periods, it has delivered the same current at 30 Hz with 45 ¿s pulses. At present, two technical problems prevent the source from being operational. It is not adequately reliable, and the beam emittance at 20 keV is larger than expected.