Mathematical models of low-pressure discharge in a magnetic field supported by UHF electromagnetic field

Electron cyclotron resonance (ECR) discharges are an effective way to generate plasma at low working gas pressure. The aim of this work is to develop a mathematical model of the ECR discharge implemented at the RAPIRA facility (RUDN University), which is used for a wide range of scientific research. The evolution of plasma particles is described within the framework of the hydrodynamic approximation (a two-dimensional model with cylindrical symmetry). A three-dimensional model of cold plasma is used to calculate the spatial distribution of the electromagnetic field. Calculations have shown that in the operating mode of the facility (gas pressures from 4· 10⁻⁴ to 10⁻² Torr, magnetic field up to 2500 G), the electron temperature is equalized along the magnetic field lines, and at the same time, the magnetic field ensures a decrease in energy losses to the side walls of the facility. The spatial distributions of the electron density and temperature and the electromagnetic field in the plasma are calculated. The implemented model can serve as a basis for developing a more advanced set of software codes that take into account the non-Maxwellian nature of the electron velocity distribution function, caused by the non-adiabatic nature of their heating in a non-uniform magnetic field.