A high-current ion source based on a hollow-cathode glow discharge with e-beam injection

Abstract

The hollow-cathode glow discharge is harnessed for generation of gas-discharge plasma and production of charged-particle beams at operating pressures of 10/sup -3/-10/sup -1/ Torr. However, the use of this type of discharge as a plasma emitter in wide-aperture gaseous ion sources calls for its operation at a pressure of 10/sup -4/ Torr or less. External injection of extra electrons into the cathode cavity provides a reduction of its lowest limiting operating pressure to below 10/sup -4/ Torr. At this pressure the electric strength of the acceleration gap is sufficient to extract an ion beam of energy several tens of KeV, and the scattering and resonance charge exchange of accelerated ions at residual gas atoms affect the parameters of the beam in this transportation toward a target only slightly. The paper is devoted to an investigation of the mass-charge composition of an ion beam extracted from the plasma of this type of high-current discharge.