Multiampere negative ion source development at Novosibirsk (invited)

Results on multiampere negative ion (NI) sources with a surface-plasma mechanism of negative ion production are presented. Several types of surface-plasma sources (SPS)emdash Honeycomb semiplanotrons and hollow-cathode Penning source emdash are reviewed. The data on SPS H-(D-) production with average NI current density in the beam up to 0.1 A/cm2 is presented. The properties of high-current glow hydrogen endash cesium discharge that produces a large-area, thin layer of plasma and provides the necessary components for intense negative ion emission and collecting (low work function coverage, electric and magnetic field distribution across the plasma, current composition to NI emitter) are analyzed. Data on efficiency and contribution of different channels of surface-plasma NI production are presented. copyright 1996 American Institute of Physics