Operation of a magnetically filtered multicusp volume source

The results of experimental studies on an optimized version of the Lawrence Berkeley Laboratory (LBL) volume source are presented. Negative ion yields and emittance data were obtained for operation with both H- and D- beams. At high arc power, H- beam currents up to 10 mA with rms normalized emittances of 0.0080 π.cm.mrad were obtained from a 6.3-mm-dia emission aperture. The yields of D- beams were approximately half those of H- beams, and the normalized emittances were 1.7 times smaller at the same current density. The results of these studies indicate that the present operation is limited by the extraction system rather than the ion source