A mass-energy balance model for strongly magnetized argon discharges

Abstract

A semiempirical physical model of a strongly magnetized argon discharge is presented. Experimental extreme-ultraviolet (EUV) spectra are analyzed and photon emission is incorporated via the most important ground-state transitions for neutral and ionic species. Other major plasma processes are also included: ionization by electron impact, wall recombination, anomalous cross field diffusion, and charge-exchange. Plasma acceleration in the ambipolar electric field is treated phenomenologically. Specific power/mass flow densities and discharge vessel geometry are factorized into equations. The resultant non-linear system of normalized stiff ordinary differential equations describes the evolution of the temperatures and densities of the plasma components under the quasi-neutrality constraint. The equations are integrated numerically using a new unconditionally stable method. The transport coefficients are deduced from a two-point comparison to experimental data. Results of multiple parametric scans are presented and discussed in detail, with emphasis on plasma acceleration and EUV light production.