Characteristics of end Hall ion source with magnetron hollow cathode discharge

Abstract

An end Hall ion source with magnetron hollow cathode discharge is described. The source is suitable for high current, low energy ion beam applications such as Hall current plasma accelerators. The end Hall ion source is based on an anode layer thruster with closed drift electrons that move in a closed path in the E×B field. Only a simple magnetron power supply is used in the ion source. The special configuration enables uninterrupted and expanded operation with oxygen as well as other reactive gases because of the absence of an electron source in the ion source. In our evaluation, the ion beam current was measured by a circular electrostatic probe and the energy distribution of the ion beam was measured by a retarding potential analyzer (RPA). An ion beam current density of up to 10mA/cm2 was obtained at a mean ion energy of 100–250eV using Ar or O2. The ion source can be operated in a stable fashion at a discharge voltage between 200 and 500V and without additional electron triggering. The discharge power of the ion source can be easily changed by adjusting the gas flow rate and anode voltage. No water cooling is needed for power from 500W to 2kW. The simple and rugged ion source is suitable for industrial applications such as deposition of thin films with enhanced adhesion. The operational characteristics of the ion source are experimentally determined and discussed.