Modeling of electron beam-generated plasmas produced in Ar/N2 mixtures*

We discuss a non-equilibrium collisional-radiative model coupled with electron kinetics developed to study the population dynamics in electron beam-generated plasmas produced in low pressure Ar/N$_{2}$ mixtures. Generally, these plasmas are characterized by low electron temperatures (1 eV), low plasma potentials, and plasma densities in the range 10$^{9}$-10$^{11}$ cm$^{-3}$. We have shown both experimentally\footnote{D. R. Boris, G. M. Petrov, E. H. Lock, Tz. B. Petrova, R. F. Fernsler, and S. G. Walton, Plasma Sources Sci. Technol. 22 (2013) 065004.} and theoretically\footnote{G. M. Petrov, D. R. Boris, Tz. B. Petrova, E. H. Lock, R. F. Fernsler, and S. G. Walton, Plasma Sources Sci. Technol. 22 (2013) 065005.} that small admixtures of nitrogen to argon leads to changes in the electron energy distribution function (EEDF) resulting in a lowering of the electron temperature from 1.0 to 0.4 eV. The modeling results show that these changes strongly impact the production of argon excited states via changes in the collisional excitation rates. The contribution of different production and destruction mechanisms of 1s and 2p argon excited states is discussed in detail. The results of the modeling are compared with the experimentally measured EEDF, electron temperature, and the optical emission spectra in 700-850 nm range.