Measurements of plasma parameters in synthesis of copper and molybdenum metal complexes

Abstract In this work, the properties of the plasma of underwater electric spark discharges generated between granules of various compositional configurations were investigated by optical emission spectroscopy. The metallic granules of pure copper, pure molybdenum, equal-volume mixture of copper and molybdenum, and copper-coated molybdenum are considered. The main attention was paid to determining the plasma parameters and calculating the plasma composition. The excitation temperature was determined by Boltzmann plot technique based on the emission intensities of metal spectral lines, while the electron density was determined based on the spectral lines’ contours broadened due to Stark effect. A simplified physical model was proposed to estimate plasma composition. Assuming local thermodynamic equilibrium and plasma electroneutrality, the plasma composition was calculated using the ratios between the atomic number densities directly determined from the experimentally recorded emission intensity of spectral lines.