Investigations on a magnetic ion source, I

Abstract

An ion source of the magnetic type has been developed, using oscillating electrons, and with the filament quite near the ion extraction hole. Space charge limited ion currents have been obtained ranging from 5 to 10 mA using extraction potentials of 6 to 15 kV. Hydrogen, helium and nitrogen gas have been used, showing an apparent mass effect. No influence of the pressure on the extracted ion current was experienced in the pressure region from 10 −5 — 10 −3 mm Hg. An experimental comparison between our source and the usual type has been carried out and the ion outputs show only small differences.