Stark halfwidth trends along the homologous sequence of doubly ionized noble gases

Abstract

Aims. The aim of this work is to analyze the behavior of experimentally determined Stark halfwidths for (n-1)d-np and ns-np transitions along the homologous sequence of doubly ionized noble gases. Methods. We analyzed the Stark halfwidth trends including all available experimental data. Stark halfwidth results for the above mentioned transitions and corresponding multiplets were compared with the halfwidths calculated using the modified semiempirical formula (MSE) and the simplified modified semiempirical formula (SMSE). In case of Ne III the calculation made by semiclassical-perturbation formalism (SCPF) is also presented. Results. Stark halfwidths corresponding to (n-1)d-np and ns-np transitions have been analyzed along the homologous sequence of doubly ionized noble gases. For all multiplets observed in this work, the analysis shows that the halfwidths of the spectral lines belonging to the same transition show a similar trend along the homologous sequence. Stark halfwidths of ns-np transitions have a clearly increasing trend. On the other hand, for (n-1)d-np transitions, there are not enough data to make a similar conclusion. This type of trend analysis can be useful for Stark halfwidth predictions and hence for spectroscopic diagnostics of astrophysical plasmas. © 2012 ESO.