Measurement of Stark broadening and shift of singly ionized Ar lines

Abstract

A very extensive compilation of Stark widths and shifts for more than 125 Ar II visible spectral lines is presented in this work. These atomic parameters have been measured in a pulsed discharge lamp by using different mixtures of pure argon or argon and helium. The electron density, which typically ranges from 0.2 to 2.0 × 10 23 m −3 has been determined interferometrically and, in the case of pure argon plasmas, also spectroscopically from H α -Stark broadening. The Ar II excitation temperature (15 000-31 000 K) has been determined by Boltzmann-plot techniques from the intensity of Ar II lines. A detailed description of all the relevant points in this kind of measurement is given. Comparisons with most of the data published about this topic for Ar II are also included.

Stark Widths of Ar II Spectral Lines in the Atmospheres of Subdwarf B Stars

“…Our Stark widths calculated as described above are presented in Table 1 along with the experimental results of [18][19][20][21][22][23]. Table 1 is organized in the following way: In the first five columns of Table 1, we give the transition array, transition, wavelength, electron temperature (T) and electron density (N e ).…”

“…In Figure 1, we present our electron impact Stark width as a function of temperature for the interval from 5000 to 60,000 K along with the experimental values of [18][19][20][21][22][23] for the transition ( 3 P) 3d 4 D 7/2 -( 3 P) 4p 4 D o 7/2 (λ = 4013.86 Å). All the experimental results are normalized to an electron density of 10 17 cm −3 .…”

Measurement of several transition probabilities in singly-ionized krypton

“…After a calibration in wavelength, dispersion was measured to be 12.59 pm/channel at 589.0 nm at the first order of diffraction with an uncertainty lower than 1% (Aparicio et al 1998). A relative intensity calibration of the spectrometer was also very carefully performed.…”

“…Concerning the 15 measured interferometric recordings, they have been processed according to the algorithms developed and described by Aparicio et al (1998) and de la Rosa et al (1990). They allow us to obtain for each wavelength an average curve of the phase evolution changes along the plasma life ∆ψ λi (t) (i = 1, 2) and from them, the electron density curve N e (t), according to the expression:…”

Stark parameters of neutral helium 318.8 nm line

“…This arrangement allows those refractivity changes that are due only to free electrons to be obtained. Interferograms for both wavelengths have been processed according to algorithms developed and described in previous works (de la Rosa et al 1990;Aparicio et al 1998), and the resulting electron density ranges from 1.25 × 10 22 m −3 to 6.22 × 10 22 m −3 in this work. Electron density was also obtained from the Stark width of He II 320.3 nm and 468.6 nm spectral lines for all instants where these lines were rather intense.…”