MULTINOMENTUM 65OMA ION SOURCE

A high-current well-focused multimomentum source of molecular ions has been developed as part of a high-energy energy-spread injection system. The multimomentum injection system is designed to produce a trapped plasma with continuous distributions of momenta and energies in order to reduce velocity-space instabilities. The ion source beam was delivered at 16-20 keV. It was composed of nine or more different species of molecular and atomic ions of hydrogen, deuterium and other gases which were extracted and focused identically and simultaneously. Maximum beam divergence was 2°from the beam axis. Average beam intensity was 130 mA/cm2 in a 2 cm dia. beam 40 cm from the source. Electrostatic focusing was accomplished by an array of 6 mm dia. accel-decel extraction and focusing apertures. The beam was 85% composed of molecular ions, of which either the diatomic or triatomic component could be maximized by an adjustment of the gas fed to a reflex arc. Operating with a mixture of hydrogen and deuterium gas, the relative intensities of the several mass-to-charge ratio beam components indicated a random distribution of protons and deuterons.