Investigation of the plasma parameters of a laboratory argon plasma source using a collisional radiative model with the comparison of experimental and simulated spectra

Abstract

Plasma spectroscopy is a common method for diagnosing the radiative behaviour and predicting the key properties of a plasma. Plasma spectroscopy may be merged with plasma modelling and simulation to perform numerical diagnostics. A new Collisional Radiative (CR) model is developed for argon plasma at low temperature and low pressure. In the developed model, rather than grouping the energy levels into lumped sets, all the energy levels up to a maximum level were modeled for both the argon neutrals and the argon single ions. With the gathered data of collisional and radiative rate coefficients from LANL (Los Alamos National Laboratory) and NIST (National Institute of Standards and Technology), this model calculates the time-varying population densities of 101 atomic and 222 ionic energy levels. The model considers the emissions of 146 Ar-I lines (in 86.68–2397.3 nm range) and 303 Ar-II lines (in 71.8–6985.3 nm range), and gives the simulated spectra over the optical and near-optical region. The simulated radiation emission spectra were then compared with the measured spectra of a laboratory helicon plasma source for the prediction of the plasma parameters such as electron temperature and electron density.