Stark broadening of hydrogen lines in dense plasmas: analysis of recent experiments.

In recent years experiments conducted by a number of different groups on line broadening of hydrogen lines, mainly ${\mathrm{H}}_{\ensuremath{\alpha}}$ on dense plasmas of densities larger than or equal to ${10}^{18}\phantom{\rule{0.3em}{0ex}}e∕{\mathrm{cm}}^{3}$ have claimed significant differences from the predictions of the standard theory. At these high densities the standard theory predictions depend on some cutoffs, necessary to preserve unitarity, the long range approximation and to ensure the validity of a semiclassical picture. Furthermore, a new, supposedly ``advanced'' theory based on a number of incorrect assumptions and/or approximations with extra exotic effects has claimed good agreement with these experiments. In this work we produce benchmark simulation calculations for these data to identify relevant and not relevant physics for the parameters of these experiments. In this way, we evaluate claims of electron-ion coupling, ion dynamics, electron vs ion broadening, nonimpact effects, and nonperturbative effects. At least one data set is seen to be dubious, in agreement with previous analyses.