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1.
M. Fitzgerald J. Khachan S. Bosi 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,39(1):35-39
Highly resolved Doppler shifted peaks of the hydrogen
Balmer lines, resulting from charge exchange of H+, H2+,
and H3+ with an H2 gas target, were obtained without the
need for a deconvolution procedure. This enabled the unambiguous
determination of the chemistry of these hydrogen species in the
units of mTorr pressure range. This was obtained from a gaseous
discharge using a biconical hollow cathode that yielded a well
collimated and monoenergetic beam. 相似文献
2.
W. F. Mahmoudi N. Ben Nessib S. Sahal-Bréchot 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,47(1):7-10
Owing to the increasing sensitivity of detectors,
accurate line profiles are needed for accurate stellar
atmospheres modelling and for laboratory and technological plasmas
as well. So, Stark broadening parameters of isolated lines of
complex atoms and ions within the impact and quasistatic
approximation are needed, even if the atomic abundance of the considered element is low.
Angular factors of the diagonal line strength entering the
quadrupole term appearing in the semi-classical expression of the
width of line broadened by electron or ion perturbers, are needed.
The aim of this paper is to extend the previous calculations of
this diagonal multiplet factor which were obtained for
configurations of the type ln and l1
nl2
m to
more complex configurations in LS coupling.
To study the Stark broadening of isolated lines in the impact and
quasistatic approximation, we use the semi-classical-perturbation
treatment, including both dipole and quadrupole contribution in
the expansion of the electrostatic interaction between the optical
electron and the perturber. We also use the Fano-Racah algebra.
Angular factors of the diagonal line strength entering the
quadrupole term appearing in the semi-classical expression of the
width of line broadened by electron or ion perturbers, are
calculated. New diagonal multiplet factor formulae for more
complicated configurations such as
(n1l1
n(LnSn)n2l2
m(LmSm)n3l3
p(LpSp))
are provided.
These formulae can enter the computer Stark semi-classical
perturbation codes. 相似文献
3.
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
4.
T. Wujec A. Jazgara J. Halenka J. Musielok 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(3):405-408
Stark broadening measurements and calculations of the Paschen γ spectral line of hydrogen ( λ = 1.094[:
MU
:]
m) are reported. Investigations have been performed at plasma electron densities between 1.4×10
15
cm
-3
and 3.7×10
15
cm
-3
. As the light source a wall-stabilized arc operated in a helium-hydrogen gas mixture at atmospheric pressure has been applied.
The radiation of the plasma emitted from nearly homogeneous plasma layers in end-on direction, was measured with the use of
a grating spectrometer equipped with a charge coupled device (CCD) detector. The radiance calibration was carried out against
light outputs originating from a tungsten strip radiation standard. The measured FWHM are compared with results of our calculations based on computer simulation techniques (full computer simulation method --
FCSM). Our broadening data are also compared with results of other theoretical approaches (MM-method, quasi-static approximation)
and with experimental data obtained at electron densities about one order of magnitude larger than ours.
Received 21 January 2003 Published online 24 April 2003
RID="a"
ID="a"e-mail: wujec@uni.opole.pl 相似文献
5.
B. Zmerli N. Ben Nessib M. S. Dimitrijević 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,48(3):389-395
We investigated here temperature dependence of Stark
widths for neutral atom spectral lines in order to find a more
precise method for scaling with temperature than sometimes used
dependence T-1/2, which is often inadequate particularly for
Stark broadening of neutral emitter lines. We found here an
analytical scaling with temperature within simplified
semiclassical approaches of Freudenstein and Cooper and
Dimitrijević and Konjević. For analysis of the temperature
dependence, lines of HeI were used. 相似文献
6.
V. Milosavljević S. Djeniže 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(3):385-390
On the basis of the precisely recorded 706.52 nm He I line shape we have obtained the basic plasma parameters i.e. electron temperature (T) and electron density (N) using our new line deconvolution procedure in the case of five various plasmas created in a linear, low-pressure, pulsed
arc discharge. Plasma parameters have been also measured using independent experimental diagnostical techniques. Excellent
agreement was found among the two sets of the obtained parameters. This enables our deconvolution procedure to recommendation
for plasma diagnostical purposes, especially in astrophysics where direct measurements of the plasma parameters (T and N) are not possible. Besides, on the basis of the observed asymmetry of the Stark broadened line profile we have obtained its
ion broadening parameter (A) caused by influence of the ion microfield to the line broadening mechanism and also the influence of the ion dynamic effect
(D) to the line shape. Our A and D parameters represent the first data obtained experimentally using the line profile deconvolution procedure. We have found
stronger influence of the ion contribution to the 706.52 nm He I line profile than the existing theoretical approximations
estimate. This can be important for plasma modeling or for diagnostics.
Received 30 October 2002 Published online 15 April 2003
RID="a"
ID="a"e-mail: vladimir@ff.bg.ac.yu 相似文献
7.
H. M. Gao S. L. Ma C. M. Xu L. Wu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,47(2):191-196
Electron densities in an atmospheric helium arc plasma have been measured with the Stark broadening parameters of helium spectral
lines. The spatially distributed radiation intensities are converted to plasma emission coefficients at every wavelength by
means of Abel inversion. From the inverted profiles of He I lines of 4713 ?, 5016 ?, and 6678 ? electron density has been
calculated, which ranges from 0.5 ×1016 to 4 ×1016 cm-3 for a helium arc with current 200 A. Stark widths of He I lines of 3889 ? and 7065 ? are determined based on the measurements
and compared with existing data. 相似文献
8.
The shapes of 12 doubly ionized gold (Au III) spectral lines have been measured in the laboratory helium plasma at about 16 600 K electron temperature and 7.4×1022 m−3 electron density. At mentioned plasma conditions the Stark broadening has been found as the dominant mechanism in the Au III line shape formation. Here presented data are the first reported values for Stark widths related to the Au III lines. The modified version of the linear, low-pressure, pulsed arc was used as a plasma source operated in helium with gold atoms, as impurities, evaporated from gold cylindrical plates located in the homogeneous part of the discharge, providing conditions free of self-absorption. 相似文献
9.
Collisional and Doppler linewidths (v
C
and v
D
) of the 469.4 nm and 473.9 nm Kr ion lines were measured in a He-Kr hollow cathode discharge using Fabry-Perot technique. A linear dependence of v
C
on He pressure was found for both lines. Significant differences were found between the temperature values deduced from the v
D
-s of the two lines, and an unexpected temperature dependence of the broadening parameter for the Kr+ 469 nm line was also observed. The temperature difference between the two lines is explained by excitation of the upper level of the 469 nm line by second kind collisions between metastable He atoms and ground-state Kr ions, while the temperature dependence of the broadening parameter of the Kr+ 469 nm line is suggested to be due to the inverse process. 相似文献
10.
C. Vadla V. Horvatic K. Niemax 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,14(1):23-25
The “forbidden” Pb 6p2
3P
0
↦6
p
2
3P1 line at 1278.9 nm is measured by diode laser absorption in a resistively heated hot-pipe filled with a lead vapour and argon
as buffer gas. The measurements performed at a temperature of 1170 K and a lead number density of 2.4×10
15
cm-3 yield the oscillator strength f
F
= (4.5±1.1)×10
-7
which corresponds to a radiative transition probability A
F
= (6.1±1.5) s-1. Within the error bars, the result is in agreement with theoretical data published by different authors.
Received 11 October 2000 and Received in final form 5 January 2001 相似文献
11.
Z. T. Alwahabi J. Zetterberg Z. S. Li M. Aldén 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,42(1):41-47
High resolution Infrared Polarisation Spectroscopy (IRPS) and Infrared Laser
Induced Fluorescence (IRLIF) techniques were used to probe CO2/N2
binary gas mixture at atmospheric pressure and ambient temperature. The
probed CO2 molecules were prepared by laser excitation to an overtone
and combination ro-vibrational state (1201, J=15) of CO2, centred
at 4988.6612 cm-1. IRPS and IRLIF line profiles were recorded for
several CO2/N2 binary mixtures. The observed IRLIF line shapes
have the expected Lorentzian form while the observed IRPS line shapes are
narrower by a factor of two than those recorded with the IRLIF and appear to
have a Lorentzian-cubed profile. The recorded line profiles provide
measurements of the pressure-broadening coefficient directly at atmospheric
pressure. The Full-Width-Half-Maxima (FWHM) pressure broadening coefficients
are measured, based on IRLIF, to be 0.2174±0.0092 cm-1atm-1 and 0.1327
±0.0077 cm-1atm-1 for self- and N2 collision broadening,
respectively. The broadening coefficients obtained based on IRPS were
measured to be ~8% larger than those obtained with IRLIF. 相似文献
12.
J.F. Kielkopf N.F. Allard A. Decrette 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(1):51-59
The theory of the Balmer α line of atomic hydrogen perturbed by collisions with protons predicts quasi-molecular satellites in the line wing due to
H-H+ collisions. Measurements of the spectrum of a laser-produced plasma confirm the existence of the strongest of these features.
< 相似文献
13.
The collisional broadening and shift of four spectral lines of neon (747.2, 748.8, 753.5, 754.4 nm) arising from 2p5 3p - 2p5 3d transitions, emitted from a low-pressure glow discharge in pure neon and neon-helium mixtures have been measured using a Fabry-Perot interferometer. The values of pressure broadening and shift coefficients are determined and analyzed in terms of the impact theory. 相似文献
14.
Agnieszka Bartecka Adam Bac?awski Józef Musielok 《Central European Journal of Physics》2011,9(1):131-137
Experimental Stark broadening studies of the infrared CI transition 3s
1
P
1
o
− 3p
1
S
0 at 833.5 nm are reported for the first time. A high-current wall-stabilized arc, operated in a mixture of helium, argon,
carbon dioxide and hydrogen, was applied as the plasma source. Radiation emitted from homogeneous and optically thin plasma
layers was analyzed. Stark broadening studies of the selected CI transition and the hydrogen Balmer β line were performed. As expected from theoretical considerations, the CI line width depends linearly on the electron density
of the plasma. Applying theoretical Stark broadening data for the H
gb
line, the measured Stark widths of the CI line were calibrated for the purpose of electron density determination in low temperature
plasmas. 相似文献
15.
V. Milosavljević S. Djeniže 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,15(1):99-104
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 相似文献
16.
J.P. Santos P. Patte F. Parente P. Indelicato 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,13(1):27-31
Using a laser-induced fluorescence method a detailed analysis of profiles of the 114Cd 326.1 nm line perturbed by argon was performed which revealed deviations from the ordinary Voigt profile. These deviations
are shown to be consistent with fits of experimental profiles to an asymmetric Voigt profile. Coefficients of the pressure
broadening, shift and collision-time asymmetry are determined and compared with those calculated in the adiabatic approximation
for different interaction potentials.
Received 19 July 2000 相似文献
17.
A. Bielski D. Lisak R.S. Trawiński J. Szudy 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(2):217-222
Using a laser-induced fluorescence method a detailed analysis of profiles of the 114Cd 326.1 nm line perturbed by N2 and CH4 was performed which revealed deviations from the ordinary Voigt profile. These deviations are shown to be consistent with
fits of experimental profiles to an asymmetric Voigt profile. Coefficients of the pressure broadening, shift and collision-time
asymmetry are determined and compared with those calculated for van der Waals interaction potential.
Received 29 November 2001 / Received in final form 12 July 2002 Published online 4 February 2003 相似文献
18.
The Balmer linesH 6 toH 12 of a calibrated HF-discharge (N e=1.45×1013cm?3) are investigated. The measurement of the line wings is extended to intensities less than 10?3 of the peak intensity. For higher lines the transition to the asymptotic Holtsmark wings is observed. The results are compared with quasistatic calculations and with predictions of the unified theory. In the former case the experimental profiles show a somewhat larger broadening, in the latter case a somewhat smaller broadening. The differences are most pronounced for lower series members. The large broadening found by Bengtson, Kepple and Tannich is not confirmed. 相似文献
19.
J. Franzke H. D. Wizemann K. Niemax C. Vadla 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(1):23-28
The collisional broadening and shift rate coefficients of the 283.39 nm (6p
2
3P0 → 7s
3P1
o
), 364.06 nm (6p
2
3P1 → 7s
3P1
o
), 368.45 nm (6p
2
3P1 → 7s
3P0
o
) and 405.90 nm (6p
2
3P2 → 7s
3P1
o
) Pb lines by He and Ar have been measured by fitting the experimental absorption line shapes to theoretical Voigt profiles.
The absorption measurements were performed in a resistively heated, Pb loaded oven with an integrated dc noble gas discharge
to produce also Pb atoms in the 6p
2
3P1 and 6p
2
3P2 metastable states. The diffusion of the metastable atoms out of the discharge zone into the neutral noble-gas atmosphere
enabled the line-shape and shift measurement of the lines involving the metastable states without the influence of the discharge
plasma. 相似文献
20.
B.K. Dutta D. Biswas B. Ray P.N. Ghosh 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(1):99-108
A near infrared diode laser spectrometer has been used for measurement of line shapes of the rotational transitions of the
() overtone-combination band of acetylene perturbed by oxygen and air. Pressure-broadening coefficients and line strength parameters
are extracted from least squares fitting of the spectra with Voigt profiles. A detailed calculation of pressure-broadening
coefficients for the self, nitrogen and oxygen broadening cases has been performed by using semi-classical impact theory based
on quadrupolar and dispersion interactions. The relative importance of the intermolecular interactions has been investigated
and it is found that for these weak interaction cases dispersive terms have a dominant role in line broadening. This is more
pronounced for the O2-broadening case. We have included all the non-resonant terms till convergence is achieved. The cutoff parameter b0 of the Anderson procedure has been determined separately for each non-resonant process. In order to include the orientation
effect of the molecules at the moment of collision we have considered an average kinetic collision diameter which sets the
lower limit of b0. This improves the result considerably and the calculated values are close to the observed results. The J-dependence of the half width is also reported and shows decrease for large J-values.
Received 24 November 1999 相似文献