DESIGN-FEATURES OF A HIGH-INTENSITY, CESIUM-SPUTTER PLASMA-SPUTTER NEGATIVE-ION SOURCE

A versatile, high-intensity, negative ion source has been designed and is now under construction which can be operated in either the cesium- sputter or plasma-sputter mode. The cesium-sputter mode can be effecte d by installation of a newly designed conical-geometry cesium-surface ionizer; for operation in the plasma-sputter mode, the surface ionizer is removed and either a bot filament or rf antenna plasma-discharge i gniter is installed. A multicusp magnetic field is specifically provid ed confining the plasma in the radial direction when the plasma-sputte r mode is selected. This arrangement allows comparison of the two mode s of operation. Brief descriptions of the design features, ion optics, and anticipated performances of the two source geometries will be pre sented in this report.