Kinetic Modeling of the Electron Cyclotron Resonance Plasma Cathode with Orifice

Electron cyclotron resonance (ECR) plasma cathodes utilize wave heating to produce a dense plasma from which electrons are extracted for a variety of applications, such as plasma thrusters. Here, we present the kinetic modeling of a plasma cathode with an orifice, where a region of enhanced ionization forms, so-called fireball. Key questions to be addressed include 1) what role does the anode fireball formation play in enhancing the extractable current, 2) what is the formation mechanism of the observed electron beam at the exit of the orifice, and 3) can this mechanism be exploited to increase the extractable current. We also explore streaming instabilities known to be present in the orifice region. The modeling was carried out using the EDIPIC code [Ref. github], and the modeling results will be validated against experimental data obtained from ECR device operation.