STUDY OF PULSED DISCHARGE OPERATION OF VOLUME H- ION-SOURCE

The pulsed operation of a negative ion volume source has been investig ated, both with and without a magnetic filter present, under condition s of full-scale acceleration of the extracted negative hydrogen ion be am. This investigation is relevant to the temporal filter concept, whi ch was recently proposed. The observation of three afterglow negative ion peaks is reported. As the negative ion current during the discharg e pulse, each of the afterglow peaks can be optimized by varying the p ressure, the plasma electrode bias, and the extraction voltage. Under optimum conditions, the negative ion current during the discharge puls e exceeds the afterglow peaks.