DEVELOPMENT OF THE NEXT-GENERATION H- ION-SOURCE FOR THE LANSCE FACILITY

The upgrade of the Los Alamos Neutron Science Center (LANSCE) will req uire an ion source producing high intensity H- beams. The new LANSCE s ource in particular will need to generate 40 mA of H- beam current at a duty factor of 12% (1 ms pulse at 120 Hz). To achieve this, the pres ent Los Alamos results were first reproduced employing a prototype sur face conversion source similar to the existing LANSCE source. Using th ese results as a benchmark for further testing, it was discovered that by moving the filament cathode into the chamber's cusp-held, the H- i on yield was enhanced. Considering this result, two extension chambers were added with movable magnetic filters at each end of the source to further improve the H- beam current. In addition, construction has be en started on a hew prototype axial source which will enable more plas ma ions to funnel across the filter field into the central region wher e the converter is located. Results of the magnetic filter operation a s well as the new axial source design will be presented. (C) 1998 Amer ican Institute of Physics.