Plasma shifts of the He iiHαandPαlines

Measurement of Stark parameters of HeII P\alpha, P\betaand P\gammaspectral lines

“…If we restrict comparisons only to experimental values obtained at similar electron densities, the best agreement is found with those by Pittman & Fleurier (1986) the differences between their data and ours being around 15%. The influence of self-absorption found by these authors should be probably considered only for electron densities lower than 0.4 × 10 23 m −3 .…”

“…As far as FWHM values is concerned, comparisons between this work results for P α line and similar data compiled from the Griem (1962) Kepple (1972) Greene (1976) Godbert (1994 Stehle (1994) This work s s s s Pittman (1986) Bacon ( literature have been summarized in Fig. 6.…”

“…Stark widths, shifts, dips and functional dependencies of their line wings. In the case of P α and P β lines, great effort has been focused on obtaining accurate measurements of these quantities (Berg et al 1962;Eberhagen & Wunderlich 1970;Bogen 1970;Jones et al 1971;Einfeld & Sauerbrey 1976;Bacon et al 1977;Soltwisch & Kusch 1979;Oda & Kiriyama 1980;Bernard et al 1981;Piel & Slupek 1984;Ackermann et al 1985;Pittman et al 1980Pittman et al , 1986Gawron et al 1988;Glenzer et al 1992Glenzer et al , 1994Hammel et al 1993;Godbert et al 1994;Konjević et al 1995;Stefanović et al 1995;Büscher et al 1996;Wrubel et al 1997) Send offprint requests to: Dr. J. A.…”

Transition probabilities of several transitions in the Ar III and Ar IV spectra

“…4. The electron density decay was measured using a well-known single laser interferometry (Ashby et al 1965) technique for the 632.8 nm He-Ne laser wavelength with an estimated error of ±7% and, also, by Stark width measurements of the convenient He II P α (468.57 nm) line (Pittman & Fleurier 1986). The electron density decay is presented, also, in Fig.…”

Tangential acceleration of helium plasma in laboratory current sheets

“…The Gaussian shape fits the Doppler and instrumental broadening, whereas the Lorenz (dispersion) profile is attributed to the Stark effect which under our experimental conditions may be associated with the electron-impact broadening mechanism. From broadening profiles like those in Figure 2, we determined the average energies of thermal and directed motion of helium ions in the x-and z-directions and the electron density in different regions of the plasma sheet, Figure 3 (Ackermann et al 1985;Pittman & Fleurier 1986).…”