Discrepancies between the Stark-broadening theories of hydrogen and measurements of Lyman-αStark profiles in a dense equilibrium plasma

Abstract

First observations are presented to the optically thin and reabsorption free-hydrogen resonance line Lyman-$\alpha$, emitted from a dense equilibrium plasma ($n_e\approx {10}^{23}$ ${\mathrm{m}}^{-3\mathrm{}}$, $T_e\approx {10}^4$ K). In the core of the line (wavelength range up to three half-widths) the Stark profiles are determined nearly exclusively by the central Stark component, which is broadened significantly more strongly than predicted by the theories. The experimental Ly-$\alpha$ Stark widths are larger by a factor of about 2.5 than theoretical ones.