Abstract
Different methods have been proposed in the past for calculating the atomic ion‐electron recombination coefficient of plasmas, for example collisional‐radiative models of D'ANGELO (1961) and of BATES et al. (1962); the “bottleneck” models of HINNOV and HIRSCHBERG (1962) and BYRON et al. (1962) modified by CHEN (1969) and WANLESS (1971); the variational theory of MAKIN and KECK (1963), modified by CURRY (1970); the J. J. THOMSON method modified by D'ANGELO (1965). Using the appropriate atomic parameters the recombination coefficients were calculated for a wide range of electron temperatures and electron densities for optically thin and optically thick hydrogen and helium plasmas. The characteristic discrepancies between the different theories are discussed. To be mentioned is the relative good agreement of the “bottleneck” models and the complete collisional‐radiative theory for optically thin and thick hydrogen plasmas at nearly all temperatures, but the agreement is less good for helium plasmas especially in the optically thick case at elevated temperatures. It is the first time that such a comparative study based on a consistent set of atomic parameters has been undertaken.