High-current pulse sources of broad gaseous and metallic ion beams for surface treatment applications

Abstract

The paper reviews the experimental study and development of technological ion sources performed under a joint IEP-IHCE program for recent years. The sources are based on pulsed high-current glow and arc discharges and are designed for surface treatment applications. The use of cold cathodes makes the sources more reliable when operated under elevated residual gas pressure and at the presence of reactive gases, while the use of a repetitive pulse mode of plasma production provides optimum conditions for stable operation of the discharge, for controlling the average beam current over a wide range, and for formation of homogeneous broad ion beams. The electrode systems used in the ion sources provide for operation of high-current discharges at low pressures, production of stable, dense, and homogeneous plasmas, and decrease the impurities content in the beam. Some design versions of the sources developed are presented that are capable of producing /spl sim/1-10 mA/cm/sup 2/ of current density in beams with a cross section of some hundreds of square centimeters at accelerating voltages of 10-100 kV, pulse durations of 10-10/sup 3/ /spl mu/s, and pulse repetition rates of 1-500 Hz. Some applications of the sources for surface modification of materials are described.