Resonant heating and transport property of electrons in a coaxially coupled electron cyclotron resonance plasma source for thruster application

A finite element method (FEM) based two-dimensional axisymmetric model of a co-axially coupled electron cyclotron resonance (ECR) plasma source is numerically simulated to investigate and optimize it as an ECR plasma thruster (EPT). The simulation model couples together a stationary magnetic field module, a frequency domain electromagnetic wave module, and a non-equilibrium plasma module to study the profiles of microwave propagation, electromagnetic energy deposition, electron heating and transport in the plasma source. The results demonstrate the resonant deposition of microwave power in a narrow region in the plasma source near the ECR zones, close to the central antenna. The electron temperature and mobility profile validate the localized heating of electrons due to ECR and subsequent magnetization. Previous works on the hybrid particle-in-cell (PIC)/fluid model of similar coaxial EPT prototype validate the current model. The model is subsequently exploited to investigate the electron mobility profile to optimize the dimension of the plasma source for an enhanced axial thrust with minimal wall corrosion effect. The resulting optimized ECR plasma source has dimensions and plasma characteristics similar to ONERA EPT prototype. This validates the use of plasma mobility, calculated using a computationally less resource intensive FEM model, as a novel parameter for EPT configuration optimization.