Stark-Broadened Profiles of the Spectral Line P_ \alpha in He II Ions

We report a systematic method to perform calculations of spectral line broadening parameters in plasmas. This method is applied to calculate Stark-broadening line profiles of P_\alpha(n=4\rightarrow n=3) transitions under certain specific plasma conditions, by treating this case as an example. In the framework of the fully relativistic Dirac R-matrix theory, we calculate the electron-impact broadening operators, which are assumed to be diagonal matrix to simplify the situation. The electric microfield distribution function is calculated by retaining Hooper's formalism. The dipole matrix elements and atomic structure parameters used in these calculations have been obtained from atomic structure GRASP code. Based on this required data, we calculate the Stark-broadened line profiles of the Paschen spectral lines in He II ions in a systematic manner. Overall, there is a very good agreement between our calculated Stark-broadened line profiles and other line broadening numerical simulation codes (SimU and MELS). Our reported spectral line-broadening data have real applications in plasma spectroscopy, plasma diagnosis and also play a fundamental role in plasma modeling.