Stark broadening of ultraviolet Ar iii spectral lines

Abstract

This paper presents the results of an experimental study of the Stark broadening and a shift of some double‐ionized argon spectral lines in a plasma of a low‐pressure‐pulsed arc. Electron densities of (3.5–9.0) × 1022 m−3 are determined by a two‐wavelength interferometry method and electron temperatures of 16 000–24 000 K are determined from the Boltzmann plot of 13 Ar ii spectral lines. The Stark parameter results obtained are analysed and compared with the available experimental results of other authors as well as with the calculated values obtained from modified semi‐empirical formulae. All investigated spectral lines belong to the ultraviolet spectral region. The data obtained can be of astrophysical interest.

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

“…For that purpose, we used the modified semiempirical formula MSE (Dimitrijević & Konjević 1980) and the simplified modified semiempirical formula SMSE (Dimitrijević & Konjević 1987) which we discuss below. The best agreement with the calculated halfwidths for Ne III is obtained with data from Konjević & Pittman (1987), Purić et al (1988) and Uzelac et al (1993); for Ar III with data from Konjević & Pittman (1987) and Djurović et al (2011) and close results from Kobilarov & Konjević (1990) and Djeniže et al (1996); for Kr III the best agreement is obtained with data from Konjević & Pittman (1987) andĆirišan et al (2011 and, finally, for Xe III with data from Konjević & Pittman (1987) and Peláez et al (2006Peláez et al ( , 2009. Taking into account experimental errors and calculation uncertainties, the experimental and theoretical data for all Ne III, Ar III, Kr III and Xe III lines for ns − np transition agree reasonably well, if we exclude results from Iriarte et al (1997).…”

“…3) are taken from Platiša et al (1975), Konjević & Pittman (1987), Purić et al (1988), Kobilarov & Konjević (1990), Djeniže et al (1996), Bukvić et al (2008) and Djurović et al (2011). Results for Kr III (Fig.…”

“…Owing to these similarities, a gradual increase of the spectral line halfwidths, i.e., the systematic trend should be expected in these cases. For the analysis of (n − 1)d − np and ns−np transitions, the following references are available: Platiša et al (1975), Konjević & Pittman (1987), Purić et al (1988), Kobilarov & Konjević (1990), Uzelac et al (1993), Djeniže et al (1996), Iriarte et al (1997), Romeo y Bidegain et al (1998), Ahmad et al (1998), Blagojević et al (2000), Milosavljević et al (2000Milosavljević et al ( , 2001, Seidel et al (2001), Peláez et al (2006), Bukvić et al (2008), Peláez et al (2009Peláez et al ( ),Ćirišan et al (2011 and Djurović et al (2011).…”

Stark widths of Ar III spectral lines in the atmospheres of subdwarf B stars

“…Electron densities of (3.5 -9.0) × 10 16 cm −3 were determined by two-wavelength interferometry method and electron temperature of 16 000 -24 000 K was measured with the help of the Boltzmann plot technique. All spectral lines for which Djurović et al (2011) measured Stark parameters belong to the UV region of 2630 -3960Å. Authors report that the errors of the measured widths vary from 15% to 50%.…”

“…Energy levels are taken from NIST database (Ralchenko et al, 2011) and oscillator strengths are calculated using Cowan code (Cowan, 1981). Our Stark widths are compared with the experimental results of (Djurović et al, 2011;Bukvić et al, 2008;Djeniže et al, 1996;Kobilarov & Konjević, 1990;Konjević & Pittman, 1987;Platisa et al, 1975). Finally, the importance of collisions with electrons in atmospheric conditions of subdwarf B (sdB) stars is studied.…”