A parameterization of the Lyman α and Lyman β line shapes for radiation transport simulations in divertor plasmas

At high divertor densities as foreseen in ITER, the hydrogen resonance radiation is trapped. This significantly affects the divertor dynamics. The model currently used for photon emission and absorption rates in EIRENE has been improved for the Lyman α and Lyman β lines. All line broadening mechanisms in the atom’s rest frame are retained, including Stark, Zeeman and fine structure effects. The influence of the ion dynamics on Stark broadening is described by a computer simulation technique. A parameterization of simulated spectral line shapes is proposed by using a fit subroutine, which allows for fast evaluation of the model in EIRENE.