Measurement of total ion flux in vacuum are discharges

Abstract

A vacuum arc ion source was modified allowing us to collect ions from arc plasma streaming through an anode mesh. The mesh had a geometric transmittance of 60%, which was taken into account as a correction factor. The ion current from twenty-two cathode materials was measured at an arc current of 100 A. The ion current normalized by the arc current was found to depend on the cathode material, with values in the range from 5% to 11%. The normalized ion current is generally greater for light elements than for heavy elements. The ion erosion rates were determined from values of ion current and ion charge states, which were previously measured in the same experimental system. The ion erosion rates range from 12-94 μg/C.