Measurement of the Stark Broadening of the Resonance Lines of Neutral Argon and Neon

Abstract

The product of the Stark width and the oscillator strength for the resonance lines of neutral argon and neon has been measured from a comparison of the Stark-broadened emission profiles of these lines with those of Lyman $\ensuremath{\alpha}$ and Lyman $\ensuremath{\beta}$, all lines saturating at the blackbody level. The Stark-broadening (damping) constant for each of the lines is found from this product using known values of their respective oscillator strengths. The lines investigated and their Stark widths for an electron density of ${10}^{16}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ are ArI1048 \AA{}, (4.6\ifmmode\pm\else\textpm\fi{}0.7)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}4}$ \AA{}; ArI1067 \AA{}, (5.1\ifmmode\pm\else\textpm\fi{}0.7)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}4}$ \AA{}; Ne I 736 \AA{}, (1.2\ifmmode\pm\else\textpm\fi{}0.5)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}4}$ \AA{}; Ne I744 \AA{}, (1.3\ifmmode\pm\else\textpm\fi{}1.0)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}4}$ \AA{}. Further, comparison of the experimental Stark profiles of the Lyman line indicates that their current theoretical line shapes agree with each other to better than \ensuremath{\sim} \ifmmode\pm\else\textpm\fi{} 10%. The radiation source employed was an electromagnetically driven $T$ tube filled with the appropriate gas mixtures of argon-hydrogen and neon-hydrogen. Electron densities and temperatures were determined from the measured half-widths of H $\ensuremath{\beta}$ and the relative intensities of selected visible lines, respectively.