Cold-cathode source of ribbon gaseous ion beams

Abstract

A ribbon ion beam source based on a magnetically confined low-pressure glow discharge has been developed. The electrode system of the ion source consists of four series-installed discharge chambers of the inverted magnetron type with a thin-wire anode. Slots are made in walls between the chambers to equalize the linear distribution of the extracted ion current density. A two-electrode multislit ion optical system 44×3 cm in size forms an ion beam having an energy of up to 20 keV. The operation voltage of the glow discharge with a current of up to 1.6 A in a magnetic field of 2–6 mT at a gas pressure (argon) of 0.015–0.03 Pa is 350–650 V. The ion beam current accounts for 8%–14% of the discharge current. The inhomogeneity of the current density distribution along the ribbon beam axis is 10%–20%.