DEVELOPMENT OF AN ION SOURCE FOR LONG-PULSE (30-s) NEUTRAL BEAM INJECTION

This paper describes the development of a long-pulse positive ion source that has been designed to provide high brightness deuterium beams (divergence ≈ 0.25° rms, current density ≈ 0.15 A cm-2) of 40-45 A, at a beam energy of 80 keV, for pulse lengths up to 30 s. The design and construction of the ion source components are described with particular emphasis placed on the long-pulse cathode assembly and ion accelerator.