Peculiarities of spectroscopy of thermal plasma with copper and molybdenum vapour admixtures

This study presents an investigation of arc discharge plasma generated between asymmetric pair of single-component copper and molybdenum electrodes. Optical emission spectra were registered in absolute intensity units with spatial resolution from the midsection of the arc column. Simultaneously laser absorption spectroscopy was carried out as well in order to determine radial distribution of optical thickness at the center of Cu I 510.5 nm spectral line. Particular attention was paid to assessing the influence of self-absorption effects, which can significantly distort the intensity of strong spectral transitions and lead to an underestimation of the spectral line intensity and, consequently, to a significant error in determining the temperature and number densities of metal atoms.