High intensity metal ion beam generation

Abstract

This investigation presents the results of the development of a vacuum arc discharge-based repetitively pulsed high-current low-energy ion beam formation for material surface modification. A DC vacuum arc was used to produce a metal plasma flow. A plasma immersion approach was used for high-frequency short-pulse metal ion beam formation. A grid hemisphere with radii of 5, 7.5 or 10.5 cm was immersed in a titanium vacuum-arc plasma. Bias pulses with an amplitude in the range of 1–2.6 kV, pulse duration in the range of 2–8 μs, and pulse repetition rate of 105 pulses per second were applied to the grid. A repetitively pulsed mode of negative bias formation provided a possibility to increase the amplitude of bias up to several kilovolts and to focus ion beams with ion space charge neutralisation. The influence of bias pulse amplitude and duration on the parameters of formed ion beams was investigated. Titanium ion beams with a current density of more than 1 A/cm2 and a pulsed ion beam power density up to 2.6 kW/cm2 were obtained. The possibility of macroparticle-free high-intensity ion beam formation for surface modification of materials was demonstrated.