Stark-broadened profiles of the Lyman spectral lines in He II ions

This paper introduces a theoretical approach for the calculations of spectral line broadening in plasmas. As an example, the line profiles of Stark broadening $L{y}_{\alpha }$ or $L{y}_{\beta }$ are calculated and investigated with this approach under some interesting plasma conditions. In our calculations, Dirac R-matrix methods are used to calculate electron-impact broadening operators, which are assumed to be diagonal matrix to simplify. The standard (Hooper) theory is chosen to calculate the electric microfield distribution function. Furthermore, the population density (b_m) of ionization state m is obtained by the Boltzmann–Saha equations. The dipole matrix and the required atomic structure data are calculated by the atomic structure GRASP package. Thus Stark-broadened line profiles of the Lyman spectral lines in He II ion are computed in a systematic manner. These spectral line-broadening parameters are considerably important for plasma spectroscopy and plasma diagnosis as well as a key stone in plasma modeling. (paper)