OES diagnostics of atmospheric pressure argon plasma: Electron temperature and density assessment through visible bremsstrahlung inversion method and collisional-radiative model

This study determined the electron temperature and density in atmospheric pressure argon plasma using optical emission spectroscopy. The analysis combined continuum and line spectral data. Visible bremsstrahlung inversion was used to derive a partial electron energy probability function (EEPF) from the continuum spectrum. Subsequently, electron temperature was estimated assuming a two-temperature distribution based on the derived EEPF. Electron density was obtained by fitting a collisional-radiative (CR) model to the line spectrum, incorporating the obtained EEPF instead of assuming a Druyvesteynian EEPF. Comparative analysis revealed that the electron densities determined using the approach were approximately one order of magnitude lower than those derived from the CR model with the Druyvesteynian EEPF. However, they exhibited strong agreement with the results obtained by the CR model using a two-temperature distribution. This approach demonstrated favorable performance in reproducing both continuum and line spectra, revealing its high reliability and accuracy for atmospheric pressure argon plasma diagnosis.