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1.
The wavelengths of the3S(3s 4s) ?3P(3s 3p) MgI transitions have been measured for the24Mg isotope with a precision of ±2 × 10?7; moreover the isotope shifts of the above transitions have been measured for the three natural Mg isotopes as well as the hyperfine constants of the3S(3s 4s) level of25Mg. The measurements have been performed in a metastable atomic beam. 相似文献
2.
P. L. Larkins P. Hannaford 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1993,27(4):313-320
Absolute frequencies of hyperfine components of the 230.6 nm (5s 2 1 S 0?5s5p 3 P 1 0 ), 193.6 nm (5s5p 3 P 0 0 ?5s6s 3 S 1), 197.7 nm (5s5p 3 P 1 0 ?5s6s 3 S 1) and 207.9 nm (5s5p 3 P 2 0 ?5s6s 3 S 1) transitions in In II emitted from a hollow-cathode source have been measured using a high-resolution, scanning échelle monochromator. The measured frequencies of these four transitions have been used to determine the energies and hyperfine interaction constants of the 5s5p 3 P 0 0 ,3 P 1 0 ,3 P 2 0 and 5s6s 3 S 1 levels in In II. The hyperfine interaction constants for the dominant isotope115In are found to be: 5s5p 3 P 1 0 A=0.2322(2) cm?1,B=?0.0159(9) cm?1 5s5p 3 P 2 0 A=0.1699(4) cm?1,B= 0.021 (6) cm?1 5s6s 3 S 1 A=0.4022(4) cm?1,B= 0.002 (2) cm?1. The absolute frequency of the very narrow, strongly forbidden In II 236.5 nm (5s 2 1 S 0?5s5p 3 P 0 0 ) transition, which has been proposed as a candidate for a new optical frequency standard, is found to be 42275.986(7) cm?1. 相似文献
3.
G. Yuan Y. Kato H. Daido R. Kodama K. Murai S. Nakai 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1994,32(1):1-5
Classification of 3-3 transitions in neonlike germanium in laser-produced plasma has been made. The spectra have been observed in the range of 185–290 Å using a high resolving power (λ/Δλ ~ 13000) grazing-incidence spectrometer in XUV laser experiment. A total of 21 lines (including five lasing lines) have been classified as transitions between the 2s 22p 53s, 3p, 3d or 2s2p 63p, 3d and sodiumlike germanium configurations. The identified transitions have been used to derive energy levels of 2s 22p 53l in neonlike germanium. The experimental results have been compared with theoretical predictions from Dirac-Fock (MCDF) calculations. 相似文献
4.
E. Träbert N. Reistad I. Martinson R. Hutton 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1989,11(3):207-211
In the EUV spectrum of foil-excited 24 MeV Ni ions the decays of the 3s 3p 3 and 3s 2 3p 3d levels to the 3s 2 3p 2 levels of the ground configuration have been observed. For most of the levels decay curves have been obtained. The lifetime results compare well with predictions from semi-empirically scaled HXR calculations. Some problems with cascade repopulations will be discussed. 相似文献
5.
J. H. Blanke P. H. Heckmann E. Träbert 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1986,3(4):375-377
Two Δn≠0 quintet transitions, 1s 2s 2p 2 5 P—1s 2s 2p 3d 5 P 0,5 D 0, have been identified in the beam-foil spectra of fluorine. The wavelengths are compared to theoretical predictions and to those of singly-excited five-electron ions. 相似文献
6.
E. Träbert R. Hutton I. Martinson 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1987,5(2):125-131
In delayed spectra of foil-excited beams of Ti, Fe, Ni and Cu ions lines have been observed which are identified with intercombination transitions 3s 2 1 S 0 — 3s 3p 3 P 1 0 , 3s 2 3p 2 P 0 — 3s 3p 2 4 P and 3s 2 3p 2 3 P — 3s 3p 3 5 S 2 0 in magnesiumlike, aluminiumlike and siliconlike spectra, resp. Wavelengths and decay properties have been determined. The results are compared to recent theoretical predictions. 相似文献
7.
B. Möbus K. -H. Schartner A. Ehresmann H. Schmoranzer 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1994,30(4):285-290
Double photoionization of argon was studied by photon induced fluorescence spectroscopy (PIFS). Cross sections for the double photoionization into the 3s3p 5 1 P,3 P states of Ar++ are presented for exciting photon energies between threshold and 120 eV. In the threshold range the energy dependencies of these cross sections were determined for the first time. Singlet and triplet states are populated with comparable probabilities at equal excess energies, in contrast to predictions of the extended Wannier theory. Athv=100 eV the spin-or-bit splitting of the 3s3p 5 3 P state was resolved, and a cross section for the production of Ar++ 3s 03p 6 1 S 0 was determined for the first time. 相似文献
8.
A. Wague 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1988,8(3):251-254
Near the (3s3p)1 P resonance of He, we have calculated the photoelectrons angular distribution asymmetry parameter β2p in the diagonalization approximation. Using the measured value of β n=2 near the (3s3p)1 P level obtained by Lindle et al. in the resonance photo-ionization of He to He?(n=2), we have estimated the ratioR=σ2p /σ2s of the partial 2p photo-ionization cross section to the partial 2s photo-ionization cross section. Our calculation supports the result that in the resonance region, the formation of ions in the 2p level dominates over the 2s level. This is in good agreement with the experimental and most of the theoretical results reported to date. 相似文献
9.
Using the non-closed shell many-electron theory for excited states of Sinano?lu we compute the hyperfine structure constants of Be I 1s22s2p 3P0, B I 1s22s2p24P and B I 1s22s2p22D. The quadrupole moment of 9Be is also newly determined to be, Q = 0.05494 barns. 相似文献
10.
W. Neu R. Neugart E. W. Otten G. Passler K. Wendt B. Fricke E. Arnold H. J. Kluge G. Ulm 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1988,11(2):105-111
The hyperfine structure and isotope shift of221–226Ra and212,214Ra have been measured in the ionic (Ra II) transition 7s 2 S 1/2–7p 2 P 3/2 (λ=381.4 nm). The method of on-line collinear fast-beam laser spectroscopy has been applied using frequency-doubling of cw dye laser radiation in an external ring cavity. The magnetic hyperfine fields are compared with semi-empirical and ab initio calculations. The analysis of the quadrupole splitting by the same method yields the following, improved values of spectroscopic quadrupole moments:Q s (221Ra)=1.978(7)b,Q s (223Ra)=1.254(3)b and the reanalyzed valuesQ s (209Ra)=0.40(2)b,Q s (211Ra)=0.48(2)b,Q s (227Ra)=1.58(3)b,Q s (229Ra)=3.09(4)b with an additional scaling uncertainty of ±5%. Furthermore, theJ-dependence of the isotope shift is analyzed in both Ra II transitions connecting the 7s 2 S 1/2 ground state with the first excited doublet 7p 2 P 1/2 and 7p 2 P 3/2. 相似文献
11.
In the state-specific theory of autoionizing states, the square-integrable wavefunction of complex coordinates corresponding to the complex eigenvalue is separated into terms contributing to the stability of the state and terms contributing to its decay. The choice and optimization of the function spaces describing these terms are different. In this work, taking the inner hole excited Be 1s 2s 2 n p Rydberg series as an example, we compute the asymptotic correlation and the concomittant energy shifts and widths by expanding the open channels in terms ofback-rotated generalized Laguerre polynomials and by diagonalizing a complex Hamiltonian matrix where the coordinates of the operator and of the occupied and virtual orbitals are real. Interchannel coupling is determined by mixing the independently optimized asymptotic pair correlation functions via the diagonalization of the total matrix. We found that, as expected, the Auger widths of both3 P 0 and1 P 0 series converge as a function ofn to the value of the previously determined width of the Be+ 1s 2s 2 2 S state. We also computed the oscillator strengths of the transitions Be 1s 2 2s 2 1 S→1s 2s 2 n p 1 P 0, which had previously been calculated within the time-dependent Hartree-Fock approximation. Forn>2, the discrepancy is large. 相似文献
12.
S. Magnier C. Angeli G. Granucci F. Masnou-Seeuws M. Allegrini M. Persico 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1997,39(4):261-265
We have computed the cross sections for the energy transfer process Cd(5p3P0) + Na(3s2S) → Cd(5s1S) + Na(4p2P) and for the state changing collision Na(4p2P) + Na(3s2S) → Na(3d2D) + Na(3s2S), based on theoretical interaction potentials for the NaCd and Na2 systems, respectively. Our calculations shed light on the interpretation of experiments with laser excited Na+Cd vapour mixtures [1]. It turns out that Cd(5p3P0), in rapid equilibrium with the doorway state Cd(5p3P1), efficiently transfers energy to Na, populating the 4p2P state. The collisions with ground state Na cause a very fast conversion of the 4p3P1 to the 3d2D state, from which the strongest emission is observed. 相似文献
13.
Hiroshi Tatewaki 《International journal of quantum chemistry》1973,7(5):971-984
The 1P and 3P states arising from the configuration (1s)2(2s)(2p) of the Be isoelectronic sequence are investigated. In the single configuration approximation, the energies of the two states are expressed as E0 + K2s2p and E0 - K2s2p, respectively. K2s2p is the exchange integral between the 2s and 2p electrons and E0 is the energy of a model in which K2s2p is deleted. First we calculate the 2s- and 2p-orbitals in this model. Second, by taking account of K2s2p in this model, effects of this term on the 2p-orbitals in the 1,3P states are investigated. In this manner, an explanation is given for the following facts which are obtained from a minimal Slater-type orbital set; (1) for Be and B+, the 2p-orbital of the 1P state is broader than that of the 3P state; (2) for C2+, the extension of the 2p-orbital in the two states is almost the same; (3) for O4+ and Ne6+, in contrast to Be and B+, the 2p-orbital of the 1P state is tighter than that of the 3P state. 相似文献
14.
Line intensities of singly, doubly and triply ionized silicon (Si II, Si III, and Si IV, respectively) belonging to the prominent higher multiplets, are of interest in laboratory and astrophysical plasma diagnostics. We measured these line intensities in the emission spectra of pulsed helium discharge. The Si II line intensity ratios in the 3s3p22D–3s24p2Po, 3s23d2D–3s24f2Fo, and 3s24p2Po–3s24d2D transitions, the Si III line intensity ratios in the 3s3d3D–3s4p3Po, 3s4p3Po–3s4d3D, 3s4p3Po–3s5s3S, 3s4s3S–3s4p3Po, and 3s4f3Fo–3s5g3G transitions, and the Si IV line intensity ratios in the 4p2Po–4d2D and 4p2Po–5s2S transitions were obtained in a helium plasma at an electron temperature of about 17,000 ± 2000 K. Line shapes were recorded using a spectrograph and an ICCD camera as a highly-sensitive detection system. The silicon atoms were evaporated from a Pyrex discharge tube designed for the purpose. They represent impurities in the optically thin helium plasma at the silicon ionic wavelengths investigated. The line intensity ratios obtained were compared with those available in the literature, and with values calculated on the basis of available transition probabilities. The experimental data corresponded well with line intensity ratios calculated using the transition probabilities obtained from a Multi Configuration Hartree–Fock approximation for Si III and Si IV spectra. We recommend corrections of some Si II transition probabilities. 相似文献
15.
C. von Borczyskowki 《Chemical physics letters》1979,68(1):146-150
Spin polarization of 81Br (I = ) nuclei is achieved via cross relaxation between electronic spins of the excited triplet state of a quinoxaline guest molecule and nuclei on neighbouring molecules in a p-dibromobenzene host crystal. The cross relaxation rate is of the order of 106 s?1 and is driven by the intermolecular hyperfine interaction. Additionally, NQR transitions have been induced in the single ground state and have been optically detected by means of an optical pumping cycle involving nuclear spin polarization. 相似文献
16.
It is known that the energy of the 2s→2p transition of light μ-atoms can be precisely measured by laser spectroscopy. Such measurements provide a good test of quantum electrodynamics predictions. Here we consider how the hyperfine muon-nucleus interaction effects on the photoexcitation of this transition and on the subsequent X-rays emission. Besides the obvious change of the transition energy the hyperfine interaction mixes the 2p 1/2 and 2p 3/2 orbits. This mixing is rather effective in μ-atoms of1H,7Li,9Be,10B and11B. Its taking into account changes the photoexcitation cross-section of electric dipole transitions between the hyperfine components of the 2s and 2p orbits and an angular X-rays distribution as well. These changes prove to be considerable for some transitions. For example, in μ2H and μ7Li the cross-section is decreased by factors of two and four respectively. In μ9Be it is increased by a factor of two. Moreover, in μ1H the angular X-rays distribution becomes more anisotropic. Besides the above subject one more question is discussed here. The fact is that the laser experiments can give an information on the residual muon spin polarization at the 2s orbit and on the degree of alignment of the angular μ-atom momentum in this state. The polarization can be determined by measuring an angular correlation between the X-rays emission direction and the momentum of a hard μ-decay electron. The alignment degree can be found by measuring an anisotropy of the angular X-rays distribution. 相似文献
17.
V. Pfeufer 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1986,2(2):141-148
The laser-atomic-beam spectroscopy has been used to make precise measurements of the hyperfine structure in transitions starting from metastable states of the configuration 4f 125d6s 2 in169TmI. With the resulting experimental magnetic dipole hyperfine constantsA J andA J values from former investigations a parametric analysis of the hyperfine structure in the configurations 4f 136s6p and 4f 125d6s 2 has been performed using wavefunctions from fine structure calculations. A comparison of theoretical and experimental hyperfine constants allowed a test of the reliability of the wave-functions used. The hyperfine parameters respectively hyperfine radial integrals determined from the analysis were compared with corresponding data from ab initio calculations for the ground configuration in TmI. 相似文献
18.
D. Kaiser Y. Liu S. Seeck Y. Kriescher G. v. Oppen 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1991,18(1):45-52
Helium atoms were excited by hydrogen-ion impact, and electric dipole transitions between Stark substates of the 1s 4f multiplet of HeI were induced. Resonance signals were investigated at various frequencies 200 MHz<ν<800 MHz by scanning a static electric fieldF 0?1 kV/cm and observing the intensity of the impact radiation for the singlet or triplet 1s 3d?1s 2p spectral line. From these measurements the following zero-field transition frequencies of the 1s 4f fine structure were deduced: ν(1 F 3?3 F 2)=232.2(1.0) MHz; ν(3 F 3?3 F 4)=214.0(1.3) MHz; ν(1 F 3?3 F 4)=490.6(0.4) MHz. Using calculated parameters of the magnetic fine-structure coupling, the exchange integral 2K=158.0(0.6) MHz of the 1s 4f configuration was evaluated. 相似文献
19.
R. E. Silverans L. Vermeeren R. Neugart P. Lievens 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1991,18(4):351-356
The hyperfine structure splittings of the 4s 2 S 1/2 → 4p 2 P 1/2, 3/2 transitions in43CaII have been measured by fast ion beam collinear laser spectroscopy. The resonant laser interaction was observed using non-optical detection based on optical ground state depopulation pumping, state selective neutralization and charge state separated particle counting. The extracted magnetic dipole hyperfine structure constants for43CaA(2 S 1/2)=?805(2) MHz,A(2 P 1/2)=?145.5(1.0) MHz andA(2 P 3/2)=?31.9(0.2) MHz are in excellent agreement with relativistic many body perturbation theory predictions available for this alkali-like ion. The combined results are used to evaluate the semi-empirical analysis method. From the electrical quadrupole hyperfine structure constantB(2 P 3/2)=?6.7(1.4) MHz and the calculatedB/Q value for this one valence electron configuration, the nuclear quadrupole momentQ(43Ca)=?0.043(9)b is derived. This result supports a previous evaluation based on the hyperfine structure of the two valence electron3 P configurations of CaI. 相似文献
20.
F. Marin C. Fort M. Prevedelli M. Inguscio G. M. Tino J. Bauche 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1993,25(3):191-199
Using high-resolution saturation spectroscopy, by means of both double heterostructure and multiple quantum-well AlGaAs diode lasers, we investigate the isotope shifts and the hyperfine structure in the 3s-3p transitions of the triplet and quintet systems of atomic oxygen. From the analysis of the signals from17O we can deduce precise values for the hyperfine structure magnetic dipole constants. A theoretical analysis allows us to bring into evidence core polarization effects in the hyperfine structure. By heterodyning two frequency locked lasers, we perform a direct frequency measurement of the isotope effect on the3 S 1→3 P 1,2,0 transitions. From the comparison with similar accuracy data on the corresponding quintet transitions, an upper bound to the size of the nuclear volume effect is given, and precise values for the specific mass contributions are consequently obtained. 相似文献