Directed cesium deposition into a large volume negative-ion source

A compact, safe system for directed cesium deposition into large volume sources is described. It consists of a small oven mounted on a feedthrough, which permits one to rotate and move the oven across the discharge chamber length or to remove it from the vacuum box to reload the oven. Special industrial pellets containing the cesium compound (30% of cesium chromate + 70% titanium) were used for a pure cesium release. The pellets are insensitive to pollution by air and can provide the cesium release during several cycles of heating and cooling in long-term experiments. There was no ''poisoning'' impurities degassing (oxygen? water) during the standard oven operation. The Cs system was reliably operated for cesium deposition in multiampere negative-ion source experiments. (C) 1996 American Institute of Physics.