Veklich A. Physical properties of thermal multicomponent plasma of electric arc discharge in metal vapours

The developed hardware and software complex tools are used to investigate the physical properties of thermal multicomponent plasma of electric arc discharge in metal vapours by optical spectroscopy. It was found, that a thermal dissociation causes the deviation of local thermodynamic equilibrium in plasma of electric arc between the melting copper electrodes in various molecular gases (air or carbon dioxide). This threshold phenomenon is determined by the ratio of the inputted into discharge energy and dissociation energy of molecular gas. To describe a chemically non-equilibrium thermal plasma of molecular gas the two-temperature model is developed. It is shown that a plasma thermal conductivity of discharge in molecular gases, in contrast to the electrical conductivity, does not depend on a presence of copper impurities in plasma in the temperature range 5000 - 9000 K. This conductivity is determined by its reaction component, which is caused by dissociation of molecules. The relation of plasma parameters of arc discharge in air between composite electrodes and а presence of secondary structure on the surface of electrodes is found. For the first time the radial distribution of copper atom concentrations in plasma was measured in a discharge gap with a presence of a drop. The influence of CuI spectral lines' reabsorption in the radiation of multicomponent thermal plasma with copper impurities is studied. It is proposed to use the thermal plasma of electric arc between multicomponent electrodes as plasma source for the spectral lines and spectroscopic data selection.