Emission Characteristics of a Constricted Arc Discharge in a Forevacuum Plasma-Cathode Source of Pulsed Electron Beam

We describe our investigation of the emission characteristics of the constricted arc discharge in a forevacuum-pressure plasma-cathode pulsed electron beam source at gas pressure 5–18 Pa. At low gas pressure the efficiency of electron emission from the constricted arc plasma is rather low, and the emission current and electron beam current appear with some delay. These features are due to low plasma density near the emission electrode of the electron source. Limitation of current through the hollow anode of the source leads to higher electron emission efficiency and shorter delay time. Increase in gas pressure and/or the use of a gas with greater ionization cross-section increases the efficiency of electron emission and decreases the delay time. Gas pressure influences the current-voltage characteristic of the electron source.