A novel numerical tool to study electron energy distribution functions of spatially anisotropic and non-homogeneous ECR plasmas

A numerical tool for analyzing spatially anisotropic electron populations in electron cyclotron resonance (ECR) plasmas has been developed, using a trial-and-error electron energy distribution function (EEDF) fitting method. The method was tested on space-resolved warm electrons in the energy range 2 - 20 keV, obtained from self-consistent simulations modeling only electron dynamics in ECR devices, but lacked real-world validation. For experimentally benchmarking the method, we attempted to use the tested EEDF to numerically reproduce experimental x-ray emission spectrum measured from an argon plasma. The analysis revealed a stronger contribution from hot electrons than expected, and this information will be fed back to simulation models to generate more realistic data. Subsequent application of the numerical tool to the improved simulation data can result in continuous EEDFs that reflect the nature of charge distributions in anisotropic ECR plasmas. These functions can be also applied to electron-dependent reactions, in order to reproduce experimental results, like those concerning space-dependent Kα emissions.