Wide gas-ion beam source based on an arc discharge in a nonuniform magnetic field
Abstract
The construction of an ion source based on a low-pressure arc with a screened cathode spot is described. The source is ignited by an auxiliary glow discharge in a magnetron electrode system. Ions are extracted from the plasma of the anode part of the arc, generated in a reflective electrode system. The effect of the magnetic induction and the emitter electrode potential on the parameters of the anode plasma was investigated, and the conditions required for generation of a dense uniform plasma, ion emission from which gives beams of ions of nitrogen, argon, oxygen, other gases with cross section ≥100 cm2, current density ≥10 mA/cm2 and nonuniformity of the plasma distribution in the beam cross section ≥10%, were determined. The formation of wide and converging beams with ion energies up to 50 keV by multiple-aperture ion-optic systems were examined. The source operates in the periodic-pulse mode. The repetition frequency of 1-msec pulses can be regulated from 0 to 50 sec-1 giving an average beam current of up to 50 mA. It is intended for use in technologies for modification of the surface properties of materials and deposition of thin films. A cold cathode makes possible prolonged operation of the source with chemically active gases.
- Publication:
-
Russian Physics Journal
- Pub Date:
- March 1994
- DOI:
- 10.1007/BF00565736
- Bibcode:
- 1994RuPhJ..37..255G