Helpful techniques for the reliable production of large (>1 A) H/sup -/ currents from cesiated surfaces at LBL

This study describes four obstacles to the reliable production of large negative ion currents from cesiated surfaces as follows: 1. Cathode-spot interruptions of either the arc or converter power supply (especially if cesium compounds accumulate) have been the dominant source of unreliability; 2. The failure to recycle cesium has produced messy clean-up operations whenever the source is vented; 3. The difficulty in achieving cold, uniform H/sup -/ current densities over large areas has made the production of lo-divergence beams cumbersome; and 4. The output current has been a weak function of the input power. This limitation has not been understood