High-current electron sources based on gaseous discharges

We review the operation of a ferroelectric plasma source (FPS) with enhanced plasma density and of high-current hollow cathode (HC) and hollow anode (HA) discharges. Different schemes (arc sources, magnetron and FPS) were used for ignition and sustaining the HC and HA discharges with current amplitude ⩽4 kA.These discharges are characterized by a positive anode potential with respect to the hollow electrode walls and the plasma density and temperature inside the hollow electrode cavity reach ∼3×1019m−3 and ⩽12 eV, respectively. It was shown that the incorporation of the FPS in the HA and HC enables one to develop a compact high-current electron source. The characteristics of an electron diode with FPS, HA and HC were studied under an accelerating voltage ⩽250 kV and ∼400 ns pulse duration. It was shown that these sources allow the generation of an electron beam with a cross-sectional area of 0.01 m2 and amplitude up to 1-2 kA.