Stark Broadening of an Ionized-Mercury Line

Abstract

The profile of the line Hg ii $\lambda 3984$ emitted from a high-current mercury arc of mean temperature 6500±800 °K and with electron density (2.6±0.7)×${10}^{16}$/cc was studied with a Fabry-Perot etalon. The full half-width of a single even-isotope component due to Stark broadening was found to be 0.39±0.08 ${\mathrm{cm}}^{-1\mathrm{}}$, in which the broadening due to the Doppler effect is subtracted, and the shift relative to an unperturbed line was found to be -0.013±0.010 ${\mathrm{cm}}^{-1\mathrm{}}$. The shift can be interpreted to be due to distant collisions of the perturbing electrons; approximately 90% of the width was found to be due to close collisions.