Stark broadening and shift of fluorine I lines

Stark widths and shifts of some prominent F I spectral lines have been determined experimentally in aZ-pinch plasma in dichlorodifluoromethane on a shot-to-shot basis. The electron density was determined by the laser interferometry while the electron temperature was measured from relative intensities of Cl II lines. Temperatures were in the range 19100–36200 °K; electron densities varied from 0.71 to 1.43×10¹⁷cm^?3. Measured F I linewidths and shifts are compared with theoretical results computed by Griem and it is shown that a) experimental widths are systematically smaller and the degree of discrepancy increases with temperature, b) line shifts are also smaller than theoretical with exception of multiplets 5 and 6 with the shifts of opposite sign than theoretically predicted, c) experimental shift-to-width ratios decrease with the temperature but less than theoretically expected. Attention is drawn in general, to the systematic discrepancy between experimental results for neutral atom lines and the theory. The magnitude of this disagreement is related to the relative position of the energy levels of spectral line to the ionisation limit.     

Stark broadening of isolated lines emitted by singly-ionized tin

Calculations have been performed on the electron impact broadening of isolated lines from singly-ionized tin from a cool plasma. These have been compared with results of measurements recently performed by Miller, Roig, and Bengtson on a plasma produced by a conventional shock tube, and satisfactory overall agreement has been obtained. Our method is similar in procedure to that of the semi-empirical approximation of Griem, but we take into account the details of the radiator structure, including configuration interaction for two of the terms. We propose a new expression from which the relevant effective Gaunt factors for singly-charged ions can be calculated for incident energies above threshold. In some cases, a significant variation of line width within multiplets is noted. Some difficulties have been experienced with transitions to states involving equivalent electrons.     

Stark broadening tables for He I λ4922Å

The Stark broadening of He I λ4922Å and its forbidden components by both ions and electrons is calculated using a theory that includes ion dynamic effects. Tables are presented for temperatures from 5000°K to 40,000°K covering the density range 10¹³ cm^-3 to 10¹⁶ cm^-3 for both helium and hydrogen ionic perturbers.     

Stark broadening parameters of the 381.96 nm He I line

Stark width (W) and shift (d) of the neutral helium (He I) 381.96 nm spectral line in the high lying 2p-6d transition has been measured in the optically thin linear, low-pressure, pulsed arc discharge operated in the helium at 50 000 K electron temperature and 6.1 x 10²² m^-3 electron density. These values are the first experimentally obtained W and d related to this line. Unfortunately, comparison with theoretical results is not possible due to the fact that only one existing theoretical calculations has been done at a 10¹⁹ m^-3 electron density only. We have found negative line shift (toward the blue) that agree well with existing theoretical predictions.Received: 19 February 2004, Published online: 4 May 2004PACS: 52.70.Kz Optical (ultraviolet, visible, infrared) measurements - 32.70.Cs Oscillator strengths, lifetimes, transition moments - 32.70.-n Intensities and shapes of atomic spectral lines     

Stark broadening of isolated spectral lines of heavy elements in plasmas

In this paper, we present results of semiclassical calculations of Stark broadening parameters for some lines of heavy neutral atoms. Comparisons with experiment show large discrepancies previously undetected for lighter elements. Critical evaluation of experimental data indicate that in most cases the experiment must be blamed for these discrepancies.     

Stark broadening of neutral helium lines

Using a semiclassical approach for the Stark broadening of atomic lines, we have calculated electron and proton impact line widths and shifts of 56 neutral He lines in the ultraviolet, visible and i.r. region of the spectrum. The comprehensive set of results obtained is used for investigation of Stark-broadening parameter regularities within the spectral series.     

Stark broadening of neutral sodium lines

A semiclassical approach has been used to evaluate Stark broadening of atomic lines and also electron-and proton-impact line widths and shifts of 30 neutral sodium lines. The results are used to investigate Stark broadening-parameter regularities within the spectral series.     

Stark broadening of neutral potassium lines

Using a semiclassical approach, we have calculated electron-proton and Ar II impact line widths and shifts of 50 neutral potassium lines. The comprehensive set of results obtained is used for investigation of Stark-broadening-parameter regularities within the spectral series.     

On the Stark broadening of the He I 447.1 nm spectral line

Characteristics of the Stark broadened and overlapping 447.1 nm He I spectral line and its forbidden 447.0 nm components have been measured at electron densities between 4.4×10²² m^-3 and 8.2×10²² m^-3 and electron temperatures between 18 000 K and 33 000 K in plasmas created in five various discharge conditions using the low pressure pulsed arc as an optically thin plasma source operated in helium-nitrogen-oxygen gas mixture. Good agreement was found among our measured line characteristics and their existing calculated values, based on the quasistatic approximation. Possible influence of the singly ionized oxygen impurity atoms (O II) on the intensity values of the dip between allowed and forbidden components was found that can explain the disagreement among some existing experimental and calculated line characteristics data, at higher electron temperatures and densities. On the basis of the observed asymmetry of the 447.1 nm spectral line profile we have obtained the ion contribution parameter at 10²² m^-3 electron density and 8 000 K electron temperature. Received 20 February 2001 and Received in final form 25 April 2001     

Stark broadening of the Al resonance lines

Absolute Stark-broadened profiles of the Al resonance lines (3p-4s, γ = 3961.5 and 3944.0 Å) have been measured under conditions of complete LTE in a conventional shock-tube. Plasma electron densities were determined by using a laser-interferometer. Uncertainties in the measurements (15% for the widths and 13% for the shifts) are discussed. The results are compared with impact-broadening calculations.     

Stark broadening of ar VIII spectral lines

Using the semiclassical perturbation method, we consider, for nine Ar VIII transitions, widths and shifts of spectral lines that are due to collisions with electrons, protons, and ions of He III ut a perturbing particle density of 10¹⁸ cm⁻³ and temperatures between 200,000 and 3,000,000 K. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 3, pp. 286–288, May–June, 2000.     

Stark broadening of Y III spectral lines

Using a semiclassical approach, we have considered electron-, proton-, and ionized helium-impact line width and shifts for 32 Y III multiplets. Published in Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 4, pp. 476–481, July–August, 1998.     

Stark broadening parameters of Si I,Si II and Si III lines

Spectral lines emited by first three ionisation species of silicon were studyed in a wide range of plasma parameters. The silicon was present as an impurity in the argon plasma created in an electromagneticT tube. Four various condenser bank energies give the plasma in a range of temperatures 8700 to 16400°K and electron concentrations 2.95·10¹⁷ cm^?3to 5.6·10¹⁷ cm^?3. Measured line widths and shifts were compared with theories of Griem [1, 2] and Sahal Brechet [3, 10]. The agreement is reasonably good, the measured values are in general smaller than calculated ones.     

Estimates of Stark broadening of oxygen ion lines

Recent measurements of spectral line widths for singly- and doubly-ionized oxygen atoms, are compared with the corresponding values predicted by the semi-empirical method of Griem. On the basis of these results, as well as a similar comparison for singly- and doubly-ionized nitrogen atoms in a recent paper, we propose some “experimental” values of the threshold Gaunt factors for these ions.     

Estimates of Stark broadening of nitrogen ion lines

Recent measurements of spectral line widths for singly- and doubly-ionized nitrogen atoms, are compared with the corresponding values predicted by the semi-empirical method of Griem. The overall agreement, for representative transitions from 6 multiples of N(II) and 3 multiplets of N(III), tends to confirm the usefulness and general validity of Griem's approach.     

Stark broadening and shift of some isolated spectral lines of singly ionised earth alkaline metals

Using aZ pinch discharge as a plasma source the profiles and shifts of some prominent ion lines of earth alkaline metals were measured and compared with Stark broadening theories and other experimental results. An electron density of 3.1 to 10.3×10¹⁶ cm^?3 was determined by the laser interferometry, while the electron temperature in the range 25100 to 34800 °K were measured from relative intensities of spectral lines. Comparison of reported experimental shifts and widths with the theories both semi-classical and quantum mechanical shows good agreement. It was also found that Griem's semi-empirical formula is useful and accurate for line widths evaluation.     

Stark broadening of singly ionized strontium and calcium lines

Profiles of five calcium II and six strontium II lines have been measured in an argon plasma behind the reflected shock wave. The plasma was produced in an electromagnetically drivenT tube and calcium and strontium were present as an impurities. Electron densities were in the range 1.91–3.40·10¹⁷ cm^?3 and the electron temperatures between 10300 and 14200 °K. The half halfwidths of the measured profiles of some Ca II and Sr II multiplets show large discrepancies with theoretical predictions.     

Stark broadening of some C(I) and N(I) vacuum ultraviolet lines

Stark widths of 11 C(I) lines and 3 N(I) multiplets were measured in the wavelength range 1310 Å ⩽ λ ⩽ 2583 Å. Gas mixtures (Ar+CO₂, Ar+N₂ and Ar+CO₂+N₂) were used for production of plasmas in a wall-stabilized arc under atmospheric pressure. Results were provided by five experiments (T varies from 13,370 to 13,950 K and N_e from 1.13 x 10¹⁷ cm^-3 to 1.35 x 10¹⁷ cm^-3. Stark shifts were measured for 2 C(I) lines and the ion-broadening parameter A was evaluated for 7 C(I) lines using different methods. The Stark widths and shifts are generally in reasonable agreement with other experimental or theoretical values, while the estimated A values are much higher than those predicted by Griem's theory.