Glow-discharge-driven bucket ion source

Abstract

A two-stage source of broad beams of gaseous ions employing a glow-discharge plasma cathode and an anode chamber with a peripheral multicusp magnetic field has been studied. A grid, whose potential approached the potential of the screen grid of the ion source, separated the cathode and anode stages. The effect of the energy (0–300 eV), the current of injected electrons (0.2–0.8 A), and the gas pressure (argon) on the plasma parameters and the efficiency of ions extraction from the plasma have been analyzed. The current density of the ions extracted from the magnetic-field-free plasma had a nearly homogeneous distribution (∼10%). The beam of 3 keV argon ions was generated using a two-electrode ion optical system with the area of ∼50 cm2. The beam current was 60 mA at the electron current of the plasma cathode equal to 0.2 A.