Simulation of Ionization and Emission Processes in the High-Voltage Electron-ion System with Cold Cathode and Pulse Ion Generator

Abstract

This paper develops the mathematical model of high-voltage low pressure electron-ion system with a cold cathode and a pulse plasma ion generator disposed behind an anode. The model is based on kinetic equations describing time dynamics of ionization processes in the plane electrode gap with participation of electrons, ions and neutral species after ion charge exchange, as well as electrode emission processes, including reflection of atoms from cathode and electrons from anode. Numerical calculations allowed revealing and studying regimes of non-self-maintained and self-maintained discharges initiated by pulse injection of ions from the anode at gas pressures, accordingly, below and above some critical value. Continuously operating ion generator is needed to maintain the non self-maintained discharge. The ion generator may be switched off after initiating the self-maintained discharge but duration of transient process of establishing this discharge can be shorted by increase of injected ion current density and injection pulse duration. Velocity and energy distributions of flows of high-energy particles going to the electrodes and time dynamics of variation of these flows are determined in different sections of the electrode gap. The obtained data is used for developing pulse electron and ion sources as well as of devices for thermo-ion deposition of materials in particular for manufacturing electromagnetic metamaterials.