A Gas-Ion Ribbon Beam Source with a Wide-Aperture Cold Hollow Cathode

A source of gas-ion ribbon beams on the basis of a glow discharge in a prolonged electrode system with a closed drift of fast electrons is described. This drift ensures a uniform plasma ion emission in the transverse direction relative to the magnetic induction vector. A discharge with a current of up to 3.5 A and a voltage of 400–600 V in a magnetic field of 6 mT is maintained under a gas flow of 40 cm³atm/min and ensures a saturation ion current density from plasma of up to 4 mA/cm² (±5%) over a length of 50 cm. Using slit-type optics with an aperture of 50 × 1 cm, a ribbon beam with a current of up to 0.2 A and an energy of argon ions of up to 25 keV has been obtained. Methods of the concentration of discharge near the emissive slit and the effect of the electron drift on the ion emission from the plasma are considered. The optimal conditions for ion beam formation are determined.