Design features of a high‐intensity, cesium‐sputter/plasma‐sputter negative ion sourcea

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 effected 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 hot filament or rf antenna plasma‐discharge igniter is installed. A multicusp magnetic field is specifically provided confining the plasma in the radial direction when the plasma‐sputter mode is selected. This arrangement allows comparison of the two modes of operation. Brief descriptions of the design features, ion optics, and anticipated performances of the two source geometries will be presented in this report.