Recent development of the fore-vacuum plasma electron sources

Summary form only given. This paper presents a review of recent development of physical and performances of co called “fore-vacuum plasma electron sources” operated at pressure range 10-100 Pa. A number of unique parameters of the e-beam were obtained, such as electron dc energy (to 20 keV), dc beam current (up 0.5 A), pulsed current (up to 100A, 1 ms) and total e-beam power (up to 5 kW). For electron beam generation at these relatively high pressures, the following special features are important: high probability of electrical breakdown within the accelerating gap, a strong influence of back-streaming ions both the emission electrode and the emitting plasma, generation of secondary plasma in the beam propagation region, and intense beam-plasma interactions that lead in turn to broadening of the beam energy spectrum and beam defocusing. The descriptions of several fore-pump plasma electron sources, its performances and parameters are also presented. Main application area is electron beam treatment of non-conducting high temperature ceramics.