Estimating the number density and energy distribution of electrons in a cold atmospheric plasma using optical emission spectroscopy

Cold atmospheric plasmas are generous sources of chemically active species, the reaction rates which can be predicted only if the electron number density and the electron energy distribution function are known. Here, the authors present a procedure for estimating both these parameters from the optical emission spectrum of an argon plasma. The peaks in the spectrum were curve fitted with Voigt profiles, and their widths and areas were mapped to the number density and energy distribution of electrons in the plasma, using the mathematical models for Stark broadening and Corona population, respectively. These plasma parameters were optimized to establish a good match between the simulated and the experimental peak attributes. This analysis estimated the value of the electron number density to be approximately 1.5 x 10(15) cm(-3) and the mean electron temperature to be approximately 0.37 eV in their plasma. It also predicted that the energy distribution of electrons can be closely approximated using a Maxwellian distribution. Published by the AVS