Experimental and 3-D PIC Simulation Analysis of Miniaturized Sheet Electron Beam Source

This article presents the performance analysis of miniaturized sheet electron beam sources (MSEBSs) carried out using experimental and simulation methods. The MSEBS is a cold cathode-based plasma-driven electron beam source. It comprises an argon gas-filled, plasma-discharge-based hollow cathode (HC) in combination with a plasma-assisted drift space. The HC is filled with argon gas and contains a circular aperture of 3 mm diameter, whereas the anode contains a rectangular aperture of 1.25 × 0.25 mm (width × height) dimensions that leads to the miniaturized sheet electron beam generation. The experimental characterization of the developed electron beam source is carried out in the applied gap voltage range of 20–30 kV under self-breakdown conditions. The experimental analysis provides the current and voltage versus time waveforms and gas discharge pressure values required for self-breakdown. Using the experimentally deduced values as input parameters, a 3-D particle-in-cell (PIC) simulation study has been carried out via VSim Multiphysics to investigate the propagation characteristics of the MSEBS-generated sheet electron beam in a similar argon gas environment. The study focuses on analyzing the beam profile evolution through an argon-filled drift space, emphasizing the effects of discharge-generated plasma on shaping of the miniaturized sheet beam. It has been found that a better sheet beam focusing within the hollow cathode phase (HCP) duration has been observed at a gap voltage of 20 kV. At higher gap voltages of 25 and 30 kV, longer HCP durations are needed for effective neutralization and better beam focusing.