Stark broadening of the hydrogen Paschen

Stark broadening measurements and calculations of the Paschen γ spectral line of hydrogen (\lambda=1.094~\hbox{\mum}) are reported. Investigations have been performed at plasma electron densities between $1.4\times {10}^{15}~\hbox{cm}^{-3}$ and $3.7\times {10}^{15}~\hbox{cm}^{-3}$. As the light source a wall-stabilized arc operated in a helium-hydrogen gas mixture at atmospheric pressure has been applied. The radiation of the plasma emitted from nearly homogeneous plasma layers in end-on direction, was measured with the use of a grating spectrometer equipped with a charge coupled device (CCD) detector. The radiance calibration was carried out against light outputs originating from a tungsten strip radiation standard. The measured FWHM are compared with results of our calculations based on computer simulation techniques (full computer simulation method — FCSM). Our broadening data are also compared with results of other theoretical approaches (MM-method, quasi-static approximation) and with experimental data obtained at electron densities about one order of magnitude larger than ours