Characteristics of High-Current Electron Gun with Plasma Anode Based on Hybrid Discharge

摘要

Spatial structure of glow and time dynamics of a hybrid discharge that combines high-current reflective discharge and vacuum arcs induced by spark breakdown on dielectric surface are studied at a supply voltage of up to 9 kV and working gas (argon) pressures of 0.1-1 mTorr. A plasma anode with an increased peripheral concentration of ions can be formed, in particular, with the aid of an auxiliary shield. Distributions of energy density are measured over the cross section of a nonrelativistic (up to 30 keV) high-current (up to 25 kA) beam generated in an electron gun with an explosive emission cathode and a plasma anode based on this (hybrid) discharge. The results are comparable with the results obtained using concentrators of magnetic field. It is expedient to employ the proposed method for improvement of uniformity of the beam, since application of the concentrators may be impossible.