Radiative effects in induction plasma modeling

While it is generally accepted that in small scale discharges plasmas can be treated as optically thin, there has been a wide discrepancy regarding the relative importance given to radiative energy transfer in induction plasma modelling. Radiative energy loss from an induction plasma has been neglected in most 1-D theoretical analysis. More recent work involving the 2-D modelling of the flow and temperature fields in an induction plasma treated radiative energy losses as a volumetric heat sink. The results show that 30-40% of the energy dissipated in the plasma can be lost as radiation. In the present study, a comparative analysis is made between available literature data on volumetric emission of an argon plasma at atmospheric pressure and their effect on the computed temperature fields. The role of radiative energy transfer from the plasma is noted to be particularly important in the presence of small concentrations of metal vapors which are known to increase considerably the volumetric emission of the plasma. Typical results given show the corresponding integral emission from pure argon plasma and an argon plasma in the presence of copper vapor resulting from the injection of 1 g/min of copper powder in the discharge