Numerical and Experimental Characterization of RF Waves Propagation in Ion Sources Magnetoplasmas

TL;DR

This study combines three-dimensional numerical simulations and experimental RF measurements to analyze wave propagation in magnetized plasmas of ion sources, enhancing understanding of wave-plasma interactions in such environments.

Contribution

It introduces a comprehensive FEM-based numerical model that accounts for inhomogeneous anisotropic plasmas and validates it with novel RF measurements in an operational ion source.

Findings

Numerical simulations successfully replicate wave-plasma interaction features.

RF measurements provide detailed local electric field data.

Comparison validates the simulation model against experimental data.

Abstract

This paper describes three-dimensional numerical simulations and Radio Frequency (RF) measurements of wave propagation in microwave-heated magnetized plasmas of ion sources. Full-wave solution of Maxwell's equations has been addressed through the Finite Element Method (FEM) commercial software COMSOL. Our numerical model takes into account the strongly inhomogeneous and anisotropic magnetized "cold" plasma medium. The simulations reproduce the main features of the wave-plasma interaction of the Flexible Plasma Trap (FPT) that recently came into operations at INFN-LNS. A two-pins RF probe has been ad-hoc developed and used as a plasmaimmersed antenna for measuring local wave electric fields in the FPT device. The measurements of plasma electron density and RF electric field, performed for different external magnetic field configuration, allowed a direct comparison with the assumed simulation model.