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1.
Common regularities for the Stark widths of the resonance lines of neutral alkali-metal, singly ionized alkali earth-metal and B III, Al III, Ga III, In III and Tl III atoms and ions respectively have been found and discussed. 相似文献
2.
《Physics letters. A》1988,126(4):280-282
Stark widths and shifts of six prominent Ne I spectral lines have been measured in linear pinch plasma sources and compared with existing theoretical and experimental results. 相似文献
3.
Photoelectric measurements of Stark widths and shifts of the components of the C(II) multiplet UV13 at 2837 Å were made with a wall-stabilized arc in a gas mixture of argon, hydrogen and carbon dioxide. Plasma diagnostics have been carried out to determine the electron density and the temperature. For experiments performed under two different physical conditions, the values ne(1) = 4.95 × 1016 cm?3, T(1) = 11,430 K and ne(2) = 6.78 × 1016 cm?3, T(2) = 12,080 K were obtained. Agreement between our widths and experimental data of Plati?a et al. is within error limits; a discrepancy of a factor of 4 appears in a comparison of our data with those of Kusch. 相似文献
4.
M.S. Dimitrijević N. Konjević 《Journal of Quantitative Spectroscopy & Radiative Transfer》1980,24(6):451-459
In this paper, we report modifications of well known semiempirical and semiclassical approximation furmulas for Stark line-width calculations. Comparisons with experiments for doubly ionized atoms yield, as an average ratio of measured to calculated widths 1.06 ± 0.31 for a modified semiempirical formula and 0.96±0.24 for a modified semiclassical formula. For triply ionized atoms these ratios are 0.91±0.42 and 1.08±0.41, respectively. Comparison with other theoretical calculations have also been made. 相似文献
5.
Stark broadening and shift parameters for resonance lines of sodium and potasium emitted by an electromagnetic T tube plasma were found to be in good agreement with theoretical data of Griem in a large range of temperature (15000 K – 26000 K). 相似文献
6.
7.
Truong Bach 《Journal of Quantitative Spectroscopy & Radiative Transfer》1978,19(5):483-491
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. 相似文献
8.
R. Ashby J.J. Clarke W.A. van Wijngaarden 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(3):327-331
6Li 32D
3/2, 5/2
states were studied using a diode laser to first excite the 2P
3/2
state and a dye laser to populate the 32D
3/2, 5/2
states. The dye laser was modulated by an electro-optic modulator and intersected an atomic beam that passed through a field
free region and subsequently through a uniform electric field. A value of 1084.24±0.20 MHz was found for the 32D fine structure splitting. The scalar and tensor polarizabilities were determined to be α
(3D
3/2
) = - 3.753±0.015, α
2
(3D
3/2
) = 2.893±0.017, α
(3D
5/2
) = - 3.772±0.008 and α
2
(3D
5/2
) = 4.058±0.013 MHz/(kV/cm)2.
Received 26 September 2002 / Received in final form 22 January 2003 Published online 11 March 2003
RID="a"
ID="a"e-mail: wlaser@yorku.ca 相似文献
9.
John D. Hey Peter Breger 《Journal of Quantitative Spectroscopy & Radiative Transfer》1980,24(5):349-364
Calculations have been performed on the electron impact broadening of isolated lines from singly-ionized and doubly-ionized oxygen emitted from a plasma of electron density 1017 cm-3 and temperature about 2 eV. These have been compared with results of measurements performed by Plati?a, Popovi?, and Konjevi? on a plasma produced by a low pressure pulsed arc. Good overall agreement has been obtained for both ionization stages, which we interpret as strong support for a recently derived expression for the effective Gaunt factor in line broadening calculations. This in turn indicates the important role that the curvature of the perturber trajectory plays in the broadening process, and that by proper allowance for this effect, classical path calculations of the isolated ion line widths can be extended to spectra of the multiply-charged ions. Some ambiguity still remains, however, as to the proper method of extrapolation of the effective Gaunt factors below threshold energies in the classical path calculation of the elastic contribution to the broadening. The present comparison appears to indicate that for the higher ionization stages, extrapolation of ? as a constant equal to its threshold value, is satisfactory. 相似文献
10.
H. O. Di Rocco 《Il Nuovo Cimento D》1990,12(11):1485-1490
Summary The shifts and widths of prominent XeII transitions are calculated in the semi-empirical approach; a very good agreement with
experimental values is obtained. The oscillator strengths were calculated using complete intermediate coefficients after energy
matrix diagonalization.
The author of this paper has agreed to not receive the proofs for correction. 相似文献
11.
John D. Hey R.J. Bryan 《Journal of Quantitative Spectroscopy & Radiative Transfer》1977,17(2):221-225
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. 相似文献
12.
John D. Hey 《Journal of Quantitative Spectroscopy & Radiative Transfer》1976,16(7):575-577
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. 相似文献
13.
14.
15.
John D. Hey Peter Breger 《Journal of Quantitative Spectroscopy & Radiative Transfer》1980,24(6):427-439
Calculations have been performed on the electron-impact broadening of isolated lines from doubly-ionized and triply-ionized sulphur emitted from a plasma of electron density 1017 cm-3 and temperature 28,500°K. These have been compared with results of measurements performed by Plati?a, Popovi?, Dimitrijevi?, and Konjevi? on a low-pressure, pulsed arc. Good overall agreement has been obtained for both ionization stages, in confirmation of our earlier conclusions based on a similar comparison for oxygen ion lines. The present calculations have been compared with calculations based upon two simplified models of Griem and the classical-path approximation of Sahal-Bréchot. Our calculated widths are in better agreement with experiment than with values obtained from the first two models; for the two multiplets, where comparison is possible, good agreement is found with the widths obtained by Sahal-Bréchot. We conclude that the present model, whereby the effective Gaunt factor is calculated, is capable of predicting reliable values for the Stark widths of isolated ion lines. Comparison with experiment [for S(III) indicates that, provided a sufficiently complete set of perturbing levels is used in the calculations, the present formula for ? may also be used for below-threshold energies in the determination of the elastic contribution to the broadening. For S(IV), an ambiguity remains in this regard, owing chiefly to a scarcity of available experimental data. 相似文献
16.
C. Fleurier S. Sahal-Brechot J. Chapelle 《Journal of Quantitative Spectroscopy & Radiative Transfer》1977,17(5):595-604
The widths and shifts of Mg+, Ca+, Sr+ and Ba+ lines broadened by electron and ion Stark effects have been measured in an argon welding type plasma. The electron density is about 1.3×1017 cm-3 and the temperature is about 13,000°K. Special care was taken to avoid self-absorption of resonance lines. Injection of alkaline earth elements into the cold region of the plasma edge permitted reliable measurements of the signs of line-shifts. Experimental results are compared with semi-classical theories and a new-classical computation of Sahal-Bréchot in which resonances of elastic cross sections are taken into account. Good agreement is observed between experiment and the later calculations. 相似文献
17.
Stark shifts of spectral lines of singly ionized earth alkaline metals have been measured behind the reflected shock wave produced in an electromagnetically driven “T” tube. The results are compared with theoretical values computed using Griem's semiempirical formula3. The agreement is generally poor. 相似文献
18.
M. A. Gigosos M. Á. González N. Konjević 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(1):57-63
We report results of the Stark broadening calculations for Sr+ and
Ba+ resonance lines in ultracold plasmas using semiempirical formulas
and numerical computer simulation technique. The simulation results show
that strong collisions dominate Stark broadening at very low electron
temperatures and weak collision approximation used recently by Vrinceanu
et al. cannot be applied in this temperature region. Consequently, the
temperature trend of Stark widths and shifts changes from
successfully used at elevated temperatures to an increasing trend
with temperature, which is characteristic for strong collisions at
low temperature. 相似文献
19.
Photoelectric measurements of lines emitted by a helium-carbon d.c. arc plasma of ne = 1.9 × 1016cm-3 at T = 12,800 K have been performed. Stark widths of 6 C(II) lines and transition probabilities for components of 3 C(II) multiplets were determined and compared with other experimental and theoretical data. Good agreement was generally observed except for the C(II) multiplets UV13 and UV14, where the results of Kusch deviate notably from others. 相似文献
20.
A. N. Gomonaĭ 《Optics and Spectroscopy》2003,94(4):488-495
The excitation of resonance lines at 226.5 and 214.4 nm, corresponding to the transitions 226.5 (5p 2 P 1 2/0 →5s 2 S 1/2) and 5p 2 P 3 2/0 → 5s 2 S 1/2, respectively, in the Cd+ ion upon collisions with monoenergetic electrons with an energy in the range of 4–130 eV is studied with high precision by a spectroscopic method in crossing beams. It is found that the dependence of the effective excitation cross sections of the resonance doublet components on the energy of the electrons has a distinct resonance structure. It is shown that the dominant mechanism responsible for this structure is the capture of an incident electron by a Cd+ ion with the simultaneous excitation of an electron from the subvalence 4d 10 shell to the autoionizing states of the Cd atom with their subsequent decay (directly or via cascade transitions) to resonance levels of the ion. The results obtained are compared with data from other experiments and with the results of the R-matrix strong-coupling calculation of 15 states and of semiempirical calculation using the Van Regemorter formula. 相似文献