Investigation of Electron Beam Generation in Pseudospark Discharge-Based Plasma Cathode Electron Source

In this paper, an investigation has been carried out for the generation of electron beam in the pseudospark discharge-based plasma cathode electron (PD-PCE) source for a wide range of geometrical and operating parameters, such as cathode aperture, gas pressure, and seed electron energy, using 2-D kinetic plasma simulation code. It has been observed that the peak electron beam current's time to appear at the anode surface decreases with an increase in the cathode aperture size, gas pressure, and injected seed electron energy. Investigation of the peak electron beam current and its time to appear at the anode is presented with reference to the variation of cathode aperture and gas pressure. It has been found that the generated electron beam current increases with increase in gas pressure while decreases with increase in the cathode aperture. The potential profile is also presented which is responsible for confinement of the plasma inside the hollow cathode (HC) cavity. The simulation has been performed for the required aperture size 2-10 mm, argon gas pressure 20-80 Pa, and seed electron energy 1-4 kV. The gas pressure, cathode aperture, and seed electron energy strongly influence the growth of plasma inside the HC cavity and also the generation of corresponding energetic electron beam. As a result, electron beams of different current amplitudes, sizes, and energies can be realized by proper control of the gas pressure, cathode aperture size, and seed electron energy of PD-PCE source for its use in extreme ultraviolet/X-ray and microwave applications.