Particle-in-Cell and Monte Carlo Modelling of Advanced Plasma Thrusters

摘要

In order to accurately assess the backflow contamination potential of electricpropulsion thrusters for spacecraft thruster integration purposes, models of the plumes and backflow are necessary. Both axisymmetric and fully three dimensional models of the plume and backflow contamination from ion thruster plumes are presented. Components included are primary beam ions, neutral propellant efflux thermal propellant ions created mainly by charge-exchange (CEX) collisions between primary beam ions and neutral propellant, non-propellant efflux (NPB) sputtered from thruster components, and neutralizing electrons. The plasma hybrid particle in cell (PlC) technique is applied to both propellant CEX ions and NPE ions produced in the beam and their transport out of the beam to the regions surrounding a model spacecraft. Simulations are performed for both single and dual thruster operation. Results of plume properties and backflow are compared with data and good agreement is found. Scaling relationships for the backflow are. determined, and the levels of NPE deposition are shown to be less than previously thought. In addition, the backflow form multiple thruster operation is