Formation of Anode Plasma in an Electron Diode with an Explosive-Emission Cathode

The results of a study of a planar vacuum diode with an explosive-emission cathode during the generation of a pulsed electron beam (250–400 keV, 100 ns, and 150 J/pulse) are presented. The formation of anode plasma during electronically stimulated desorption of molecules and impact ionization in an anode gas layer is simulated. The total charge of anode-plasma electrons was ≈ 10% of the electron-beam charge and corresponds to the calculated ones for a cross section of electron-stimulated desorption of (0.5–2) × 10 –14 cm 2 . The values obtained exceed the data of others researchers due to taking the contribution of the ionization of adsorbed molecules to their desorption into account. It is shown that the thermal desorption of molecules from the anode surface and electron degassing of the anode material make a negligible contribution to the formation of the anode gas layer.