Influence of metal vapours on arc properties

The plasmas formed by mixtures of gas and metallic vapours have properties quite unlike those of the plasmas of the pure gases. Even at low concentrations (0.1% for example) metal vapours can strongly modify the coefficients of electrical and thermal conductivity and more generally, the transport coefficients. In particular the radiation of a plasma can be greatly increased in the presence of vapours. This effect does not depend on the vapor alone but also on the gas with which it is mixed. In the energy balance at the electrodes, it is necessary to take the influence of the vapours into account. It must also be take into account in the calculation of the power received by a particle vapourised in a plasma for plasma projection applications.