Radiative energy loss in a non-equilibrium argon plasma

The total radiative loss in atmospheric argon plasmas is calculated allowing for deviations from local Saha equilibrium LSE. The authors have taken into account non-equilibrium excited state populations using numerical and analytical collisional-radiative models. Simple expressions for the different radiation loss mechanisms are given in terms of the electron density, electron temperature and ionization degree. These quantities together with the heavy particle temperature also define the deviation from equilibrium. In the recombining zones the effect of non-equilibrium will have significant influence on the total radiative loss due to line radiation. The dominancy results from the fact that the electron density in a recombining plasma is much larger than the value predicted by Saha. The results can also be used for non-atmospheric argon plasma provided that n_theta >5*10¹⁹ m^-3 and n(1)d>10²⁰ m^-2 in which d is the plasma dimension.