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1.
H.L. Xu A. Persson S. Svanberg 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(2):233-236
New radiative lifetime measurements based on time-resolved laser-induced fluorescence techniques are reported for 18 even-parity
levels belonging to the 4f5d26p and 4f
25d
2 configurations of Ce I and 6 even-parity levels belonging to the 5d26s, 4f5d6p, and 4f6s6p configurations of Ce II. Free neutral and singly ionized cerium atoms were produced by laser ablation. The Ce I and Ce II
levels range in energy from 26 545 to 29 102 cm-1, and 42 573 to 48 152 cm-1, respectively.
Received 25 September 2002 Published online 4 March 2003 相似文献
2.
S. Kröger I. K. Öztürk F. G. Acar G. C. Başar G. Başar J.-F. Wyart 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(1):61-70
A parametric analysis of the fine and the magnetic dipole hyperfine structure
for the three configurations of odd parity 4d35s5p, 4d45p and
4d25s25p was performed.
Effective one-electron parameters were determined and
theoretical predictions are given for the magnetic dipole
hyperfine structure constants A
for the levels of these three configurations.
Additionally,
12 new energy levels could be found, four of odd and eight of even parity,
by re-analysing data for experimental wavelengths of Nb. 相似文献
3.
S. Kröger A. Bouzed 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(1):63-72
A parametric analysis of the fine and the hyperfine structure for the three even configurations 4d45s, 4d
45s
2 and 4d5 has been performed. Effective one-electron parameters a
nl
kskl(k
s
k
l = 01, 12 and 10) and b
nl
02 were determined for these three configurations. Extremely large ratios a
4d
10/a
4d
01 were found. Theoretical predictions for the hyperfine structure constants A and B for all levels of the configurations 4d45s, 4d
45s
2 and 4d5 have been determined from experimental data. Additionally, the fine and hyperfine structure for the two energetically high
lying even configurations 4d46s and 4d35s6s are discussed. The results presented here call into doubt the existence of the fine structure levels 4d
35s6s
6
F
11/2 at an energy of 39 408.88 cm-1 and 4d
35s5p
6
G
13/2 at 18 876.46 cm-1 given in the Moore tables. 相似文献
4.
H.-L. Xu Z.-K. Jiang S. Svanberg 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(3):323-326
Natural radiative lifetimes of eight levels in Tm I ( 4f
135d6p and 4f
125d6s
2 configurations), two levels in Tm II ( 4f
125d6s configuration) and three levels in Tm III (4f
125d configuration) have been measured by using time-resolved laser spectroscopy. Free thulium atoms, as well as singly and doubly
ionized ions, were obtained in a laser-induced thulium plasma and the investigated states were selectively populated by a
single-step excitation process with a tunable narrow-band laser pulse.
Received 20 August 2002 / Received in final form 7 January 2003 Published online 4 March 2003
RID="a"
ID="a"e-mail: huailiang.xu@fysik.lth.se 相似文献
5.
Radiative lifetime measurements have been performed, with a time-resolved laser-induced fluorescence technique, for 20 odd-parity levels of La I belonging to the configurations 5d
26p, 5d6s6p and 4f5d6s. The new results are compared with the few experimental data available in the literature and with theoretical calculations including configuration interaction effects. The agreement theory-experiment is generally satisfying but discrepancies are observed for some levels emphasizing the difficulty to get a reliable theoretical model in such a heavy and complex neutral element.Received: 26 January 2004, Published online: 22 June 2004PACS:
32.70.Cs Oscillator strengths, lifetimes, transition moments - 42.62.Fi Laser spectroscopy 相似文献
6.
Yu.P. Gangrsky V.D. Karaivanov B.N. Markov S.G. Zemlyanoi Tz.T. Kokalova K.P. Marinova E. Stachowska J. Dembczynski J. Ruczkowski B. Arcimowicz 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(3):341-345
The laser-induced resonance fluorescence in an atomic beam was used in order to measure the hyperfine splitting of the 4f
7 6s
2
and 4f7 6s6p
levels in 151,153,155Eu isotopes. The hfs constants A and B of the unstable 155Eu were determined for the first time: MHz, MHz and MHz. With these data and after corrections for second-order hyperfine structure perturbations the nuclear moments of 155Eu were deduced: n.m. and b. In addition new and more precise values of the hfs constants of the excited state for the stable 151,153Eu were obtained. They are as follows: MHz, MHz and MHz, MHz. The hyperfine anomalies % and % were extracted from the corrected hfs constants.
Received 28 July 1999 and Received in final form 14 January 2000 相似文献
7.
8.
9.
We have measured the gettering efficiencies for Cr, Mn, Fe, Co, Ni and Cu in p/p+ epitaxial wafers. The gettering test started with a reproducible spin-on contamination on the front side of the wafers in
the 1012–1014 atoms/cm2 range, followed by thermal treatment to redistribute the metallic impurities in the wafer. The gettering efficiencies were
measured by a novel wet chemical stratigraphic etching technique in combination with inductively-coupled plasma mass spectrometry.
The residual bulk metal contamination was also measured by this method. This procedure led to global distributions of the
3d elements on the wafer’s front side, in the bulk of the wafer and on the wafer’s back side. Recovery rates were found to be
34%, 2.3%, 100%, 85%, 100% and 100% for Cr, Mn, Fe, Co, Ni and Cu, respectively. An impurity segregation effect in the wafer
bulk was measured for Cu (100%) and Cr (34%), while no detectable segregation-induced gettering mechanisms were detected for
the other elements in the applied concentration range. The segregation-induced gettering mechanisms were interpreted from
the electronic structure of the metallic impurities. For segregation gettering by increased solubility in p+ silicon, the metallic species must form donors. Only Cu+ (3d
10) and Cr+ (3d
5) can form singly positively charged species that exhibit a spherical electronic distribution. It is well known from spinell
structures that 3d
10 and, to a smaller extent 3d
5, are stable configurations in tetrahedral structures like the silicon lattice. Thus, we link the segregation-induced gettering
mechanism in p/p+ epitaxial wafer to the electronic configuration of the 3d elements.
Received: 19 January 2001 / Accepted: 31 January 2001 / Published online: 20 June 2001 相似文献
10.
The spectrum of neutral chromium (Cr I) has been investigated in detail. It is basically a sixelectron system, exhibiting
a very complex structure with its ground configuration 3d
54s. The low lying excited configuration is 3 d
54p and the core excitation leads to 3d
44s4p. Further excitations of these configurations give rise to 3d
54d, 3d
44s
2. In the past, a large number of levels have been reported without any satisfactory theoretical support. In the present work
we have observed the spectrum of Cr on a 35 ft grating of our laboratory in the wavelength region 4800–5500 ? and have carried
out configuration interaction (CI) calculations for abovementioned configurations. Known levels have been used to optimize
the energy parameters of least squares fitted parametric calculations. These parameters were used to predict the unknown levels
more precisely. Among 1014 energy levels, 652 levels are newly predicted (208 listed in the tables and 444 levels lying above
66500 cm−1 are available privately on demand). 相似文献
11.
The hyperfine structure constants A and B of all139La II even levels with 5d 2 and 5d6s configurations have been measured, mainly by high-resolution spectroscopy on collinear laser-ion-beams. Morover some A and B constants of odd-parity levels have been obtained. 相似文献
12.
E. Behar P. Mandelbaum J.L. Schwob 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,7(2):157-161
Ab initio calculations of the total dielectronic recombination (DR) rate coefficient of Ni-like barium () and tungsten () in the ground state have been performed using the HULLAC atomic code package. Resonant and nonresonant stabilizing radiative
transitions are included. Collisional transitions following electron capture are neglected. The present level-by-level calculations
include the DR contributions of all of the levels (over 17000) in the Cu-like inner-shell excited configurations 3d
9
4ln'l' (), 3p
5
3d
10
4ln'l' (), and 3s3p
6
3d
10
4ln'l' (). For both ions, the configuration complexes with a hole in the 3p inner shell contribute almost 10% to the total DR rate coefficient, while the complexes with a hole in the 3s inner shell
contribute about 1%. The converging contributions of the 3d
9
4ln'l' (n' > 9) configurations are evaluated by applying the complex-by-complex extrapolation method and are found to comprise up to about 20% of the total DR rate coefficients throughout a wide electron
temperature range. The total DR rate coefficients are fitted to an easy-to-use analytic expression which reproduces the original
data with an accuracy of about 2% or better in a very wide temperature range.
Received: 1 February 1999 相似文献
13.
The hyperfine structure and the isotope shift of transitions between metastable levels of the configuration 4f 75d6s and levels of the configuration 4f 75d6p of151Eu and153Eu were studied by means of the high resolution laser-atomic-beam technique. The metastable states were populated by an arc discharge burning in the atomic beam. The measured hyperfine constantsA andB of the 4f 75d6s configuration allow to perform a parametric analysis using the effective tensor operator formalism. For the first time the nuclear quadrupole moments are deduced from the quadrupole interaction parameters of the 5d electron in Eu I. The values uncorrected for the Sternheimer effect are151 Q(5d)=1.53(5)b and153 Q(5d)=3.92(12)b. A comparison with the quadrupole moments derived from the 6p electron and the intrinsic quadrupole moment of153Eu gives information about Sternheimer's correction factors. The value found for the hyperfine anomaly due tos electrons in the 4f 75d6s configuration agrees very well with previous results in other Eu configurations. The change in the mean-square nuclear charge radius is derived from the isotope shift measurements and compared with the results obtained from other optical transitions in Eu. The mean value isgd〈r 2〉151, 153 =0.577(25) fm2. 相似文献
14.
The fine structure and the hyperfine structure for some singly-excited and doubly-excited states of helium atom are calculated using Rayleigh-Ritz variational method with multi-configuration-interaction wave functions. The calculated results of the fine structure for the Rydberg series are in good agreement with other theoretical and experimental data. The hyperfine parameters and the hyperfine coupling constants of 3He are also obtained for this system.Received: 17 January 2003, Published online: 29 July 2003PACS:
32.10.Fn Fine and hyperfine structure - 31.30.Gs Hyperfine interactions and isotope effects, Jahn-Teller effect 相似文献
15.
The hyperfine structure of157Gd was investigated in 20 Gd II lines by means of a photoelectric recording Fabry-Perot interferometer with digital data processing. The hyperfine splitting factors,A andB, were obtained by computer fits to the observed line structures. Using a multiconfigurational set of wave functions in intermediate coupling derived by Wyart, mono-electronic hyperfine parameters were deduced by a parametric treatment. The nuclear electric quadrupole moment of157Gd was evaluated from the quadrupole interaction of the 5d electron in 4f 7 5d6s, the 5d electron in 4f 7 5d6p, and the 6p electron in 4f 7 5d6p. The three values obtained for the quadrupole moment agree very well. The final result, corrected for Sternheimer shielding, isQ(157Gd) =1.34(7)·10?24 cm2. 相似文献
16.
E. Luc-Koenig M. Aymar M. Millet J.-M. Lecomte A. Lyras 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,10(2):205-223
We have investigated theoretically the asymmetrical photoionization yields into the 6s
1/2, 5d
3/2 and 5d
5/2 continuum channels of atomic barium observed by Wang, Chen and Elliott [Phys. Rev. Lett. 77, 2416 (1996)] in the study of coherent control through two-color resonant interfering paths. The atomic parameters obtained
from a theoretical approach based on a combination of jj-coupled eigenchannel R-matrix and Multichannel Quantum Defect Theory are used to analyze the photoionization spectra from the and 6s7p
states with polarized light beams. The studied energy range includes the 6p7p autoionizing resonances. The dynamics of the two-color photoionization is governed by the coherent excitation of the 6s6p and intermediate states. This excitation is described as an adiabatic process in the rotating wave approximation. The influence
of the radiative decay, spatial distribution of the intensities of the laser beams and hyperfine interaction is discussed.
Received 28 September 1999 相似文献
17.
The 4p 64d?(4p 65p + 4p 64f + 4p 54d 2) transitions in the spectra of In XIII-Sn XIV and the 4p 64d 2?(4p 64d5p + 4p 64d4f + 4p 54d 3) transitions in the spectra of In XII-Sn XIII are investigated. About 150 spectral lines in the wavelength range 120–160 Å, which is important for projection vacuum UV lithography, have been classified for the first time. The fine structure intervals of the ground state 4p 64d 2 D and the energies of eight levels of the 4p 65p, 4p 64f, and 4p 54d 2 configurations are measured in each spectrum of In XIII and Sn XIV. The energies of all levels of the ground configuration 4p 64d 2 and the energies of 35 levels of the interacting configurations (4p 65p + 4p 64f + 4p 54d 3) are determined in the spectra of In XII and Sn XIII. The resonant transitions 4p 6 1 S 0?4p 54d 1 P 1 in the spectra of In XIV and Sn XV are also identified. The semiempirical parameters of the configurations under study determined by mean-square fitting of measured level energies are in agreement along both isoelectronic and isonuclear sequences of the spectra. 相似文献
18.
P. Grundevik H. Lundberg L. Nilsson G. Olsson 《Zeitschrift für Physik A Hadrons and Nuclei》1982,306(3):195-209
High-resolution laser fluorescence spectroscopy, using a single-mode dye laser acting on a collimated atomic beam, has been performed to determine the hyperfine-structure (hfs) constants in six states of the 6p 5d configuration of135Ba and137Ba. Isotope shifts (IS) for eleven transitions between the 6s 5d and the 6p 5d configurations have also been measured. From an analysis of the energy levels, intermediate angular wavefunctions have been deduced. The wavefunctions are used to evaluate experimental hyperfine parameters from the experimental hfs constants. The parameters are, for the magnetic-dipole interaction compared with theoretical values, and for the electricquadrupole interaction used to estimate the nuclear quadrupole moments for the odd isotopes. The IS in the measured transitions are analysed using a King-plot, with the first resonance line in Ba II as the reference. Specific mass and field shifts are evaluated for the measured transitions. The field shifts have been used to determine the change in mean-square radius between the natural abundant Ba-isotopes. 相似文献
19.
The spectrum of Bi VI in a wavelength region of 177–431 Å was studied. The transitions from the levels of the interacting configurations 5d 86s6p+5d 97p+5d 95f+5d 96f to the levels of the 5d 10 and 5d 96s configurations were analyzed. 174 spectral lines were identified, and 79 new levels of high-lying odd configurations of Bi VI were found. 相似文献
20.
J. Bauche J. -F. Wyart Z. Ben Ahmed K. Guidara 《Zeitschrift für Physik A Hadrons and Nuclei》1982,304(4):285-292
The hyperfine structures (hfs) of the levels of the 5d 2 and 5d6s configurations of La II, recently measured very accurately by Höhle, Hühnermann and Wagner, are interpreted in the classical parametric scheme. For the magnetic part, the contribution of the two-body far-configuration-mixing effects is determined accurately from the hfs of four levels, and compared with an ab-initio evaluation. For the electric part, all three 5d parameters are determined. The Sternheimer corrections to the radialr ?3 integral are computed by the Multiconfigurational-Hartree-Fock method, and a corrected value of the electric-quadrupole nuclear moment is deduced:Q(139La)=0.20(1) 10?24 cm2. 相似文献