类铍BⅡ离子激发态的相对论能量和精细结构

利用多组态相互作用方法及Rayleigh-Ritz变分法,计算了类铍BⅡ1s²2s^{2 1}S,1s²2s2p¹P⁰,1s²2s2p³P⁰和1s²2p^{2 3}P激发态的能量.运用截断变分方法得到能量的改进量.计算了相对论修正、质量极化效应,从而获得了高 关键词： 类铍离子 精细结构 振子强度 辐射跃迁     

Hartree-Fock Energies of the Doubly Excited States of the Boron Isoelectronic Sequence

Hartree-Fock energies of the 1s² 2s 2p ns(⁴P), 1s² 2s 2p np(⁴P, ⁴D) and 1s² 2s 2p nd(⁴P, ⁴D); n = 3–6 states in the boron isoelectronic sequence are reported. The results show a fairly good agreement with the experimental data of Bromander for O IV.     

Wavefunctions and oscillator strengths for MgIX,SiXI, ArXV,CaXVII and FeXXIII

Configuration interaction wavefunctions for the 1s²2s^{2 1}S, 1s²2s2p³P⁰,¹p⁰ and 1s²2p^{2 3}P,¹D,¹S, states are calculated for MgIX, SiXI, ArXV, CaXVII and FeXXIII and are used to calculate oscillator strengths, both the length and velocity forms, for transitions between these states.     

Sensitivity of the electronic-interaction parameters used in molecular calculations to correlation effects

The correlation corrections to the one-center Coulomb integrals are calculated for the⁵S(1s²2s2p³) state of carbon, the⁴P(1s²2s2p⁴) state of nitrogen and the³P(1s²2s²2p⁴) state of oxygen. The calculated results are compared with semiempirical values. A satisfactory agreement is found for all three atoms.Translated from Izvestiya VUZ. Fizika, No. 3, pp. 119–122, March, 1970In conclusion the author thanks his colleagues in the Theoretical Physics Laboratory and the Optics and Spectroscopy Laboratory, Siberian Physicotechnical Institute, for many fruitful discussions of these topics.     

Hyperfine-structure studies of the 1s<Superscript>2</Superscript>2snp (n=2, 3) <Superscript>3</Superscript>P states for the beryllium isoelectronic sequence

The hyperfine structure parameters of the 1s²2snp (n=2, 3) ³P states for the beryllium isoelectronic sequence from Z= 4 to 10 are calculated with the full-core plus correlation (FCPC) wave functions. For the 1s²2s2p ³P state of the beryllium atom, the calculated fine structure parameters are in good agreement with the latest theoretical and experimental data in the literature. It is shown that hyperfine constants of the low-lying excited states for the beryllium atom can be calculated accurately using this theoretical method. For 1s²2snp (n=2, 3) ³P states of the beryllium isoelectronic sequence, our predictions may provide valuable reference data for other theoretical calculations and experimental measurements in future.     

Many-body theory for simultaneous photoionization and photoexcitation of helium

Brueckner-Goldstone many-body perturbation theory is applied to study the simultaneous photoionization and photoexcitation (SSP) of helium. The results are used to examine the validity and limitations of other approaches to the problem. The oscillator strengths ($\text{d}\text{?}\text{?}$) for the transition 1s²→(2s ?p)¹P and 1s²→(2p ?s)¹P are compared with the results of Brown. The cross section for SPP at the photoexcitation threshold (65.399 eV) is found to be in agreement with the experimental result of Samson.     

Excitation of multiplet states in neon

High resolution Auger electron measurements of neon have been made using electron, proton, alpha and oxygen ion excitations. Energies and intensities have been extracted for transitions with initial states ³P and ¹P (with configuration 1s¹ 2s² 2p⁵). In general, the population ratio of triplet P to singlet P is independent of the type of incident ion, but this ratio is seen to differ significantly from the statistical expectation.     

Mechanisms of broadening of emission lines of a laser-induced plasma generated on the surface of rigid targets

This article reports the results of an experimental investigation of the basic mechanisms that cause the broadening of emission lines of a laser-induced plasma generated on the surface of rigid targets in a gaseous atmosphere. The contribution of Stark and resonance mechanisms of emission-line broadening for the resonance doublet Al I 3s²3p²P_3/2,1/2-3s²4s²S_1/2 and triplet Mg I 3s3p³P _0,1,2 ⁰ -3s4s³S₁ is discussed. The concentrations of neutral Al atoms in the laser-induced plasma are evaluated by the magnitude of resonance line broadening. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 2, pp. 234–237, March–April, 2000.     

Theoretical study of the spectra of the oxygen isoelectron series

By applying perturbation theory to the reciprocal of the nuclear charge (1/Z), the spectra of a series of oxygen-like ions (having configurations of the 1s²2s²2pⁿ, 1s²2s2pⁿ⁺¹, 1s²2pⁿ⁺², n =4 type) are calculated. The results of the calculation are compared with existing experimental data. The difference between the theoretical and experimental energies of the terms is 0.1–1%.     

K-shell Auger rates for multiply-ionized atoms: I. Neon

Theoretical Auger rates for the various terms of electron configurations 1s¹2s²2pⁿ, 1s¹2s⁰2pⁿ and 1s¹2s¹2pⁿ to the final terms after the Auger transitions are presented. The calculations are performed with the Hartree-Fock-Slater model. These rates can be conveniently used in the analyses of Auger-electron spectra produced, in particular, by heavy-ion collisions with neon.     

New classifications in the spectrum of helium-like fluorine (F VIII)

New transitions, belonging to the series 2p¹P-nd¹D, 2s³S-np³P and 2p³D, are reported in the spectrum of helium-like fluorine (F VIII).     

Transition energy and dipole oscillator strength of 1s23d-1s2 nf transitions for Sc18+ ion

The transition energies of the 1s²3d-1s² nf (4?n?9) transitions and fine structure splittings of 1s² nf (n?9) states for Sc¹⁸⁺ ion are calculated with the full-core plus correlation method. The quantum defect of 1s² nf series is determined by the single-channel quantum defect theory. The energies of any highly excited states with n?10 for this series can be reliably predicted using the quantum defect as function of energy. Three alternative forms of the dipole oscillator strengths for the 1s²3d-1s² nf (n?9) transitions of Sc¹⁸⁺ ion are calculated with the transition energies and wave functions obtained above. Combining the quantum defect theory with the discrete oscillator strengths, the discrete oscillator strengths for 1s²3d-1s² nf (n > 9) transitions and the oscillator strengths densities corresponding to the bound-free transitions are obtained.     

Angular distribution and polarization of photons during resonant above-threshold scattering on an atom

The effect of the resonant structure in the continuous spectrum induced by an external laser field due to the coupling of continuum states with the 1s4s ¹ S level in helium on cross sections of elastic and inelastic scattering of probe radiation on an atom in the metastable 1s2s ¹ S state at an energy above the ionization threshold is theoretically studied. Explicit expressions for the angular distribution and the degree of polarization of scattered photons as functions of probe and laser radiation characteristics are derived in the rotating wave approximation. Frequency, angular, and polarization dependences of the cross sections of scattering into final 1s ^{2 1} S, ¹ s2s ¹ S, and 1s4s ¹ S atomic states are calculated.     

Electric Dipole Oscillator Strengths and Radiative Lifetimes in the Boron Isoelectronic Sequence

Oscillator strengths for the 2s²ns(²S) ?2s²mp(²P), (n = 3–6, m = 2–6) and 2s²np(2P) ?2s²md(²D), (n = 4–6, m = 3–5) transitions in B I sequence are calculated in LS-coupling scheme. The Coulomb approximation is used in calculating the radial part of the wave functions, while the angular part is determined using the Racah technique. Lifetimes of the ns(²S) and np(²P), (n = 3–6) excited states are evaluated and compared with previous results from beamfoil experiments.     

Quantum electrodynamic calculation of interelectron interaction for He-like and Li-like multiply charged ions

Exact quantum-electrodynamic calculations of the interelectron interaction corrections are performed for the 1s _1/22s _1/2 ¹ S ₀, 1s _1/22p _1/2 ³ P ₀, and 1s _1/22s _1/2 ³ S ₁ configurations in He-like ions and for the (1s _1/2)²2s _1/2 and (1s _1/2)²2p _1/2 configurations in Li-like ions for all charges of nuclei 10≤Z≤92. The calculations are performed in the Coulomb calibration. The Coulomb-Coulomb and the Coulomb-Breit parts are calculated exactly, and the Breit-Breit part of the correction is calculated by neglecting the retardation. The calculations are the most exact of those available by now.     

Behaviour of hartree-fock and hartree-fock-slater (Xα) atomic form factors and electron momentum distributions for two-, three- and four-electron ions

The atomic form factor and the radial electron density in momentum space, from the solutions of the α-parameterized Hartree-Fock-Slater (Xα) equations, are studied within the framework ofZ ^?1 expansion theory for the two-, three- and four-electron ions in their ground state configurations (1s ²), (1s 1s′ 2s), and (1s ² 2s ²), and compared with the corresponding Hartree-Fock quantities.     

Theoretical study on behaviors of 1s22s-1s2np transition for Co24+ ion in the whole energy region

Non-relativistic energies of 1s²2s and 1s² np (n⩽9) states for Co²⁴⁺ ion are calculated by using the full-core plus correlation method. Our results of 1s²2s and 1s²2p states agree well with the high-precision results of Yan et al. Based on calculating the first-order corrections to the energy from relativistic and mass-polarization effects, we estimate the higher-order relativistic contribution and QED correction to the energy under a hydrogenic approximation. The transition energies, wavelengths and oscillator strengths for the 1s²2s−1s² np (n⩽9) transitions of this ion are calculated. The results agree with the experimental data available in literature satisfactorily. By combining with quantum defect theory, our theoretical predictions on the energy and oscillator strength of this ion are extrapolated to the whole energy region including continuous states.     

New procedure for generating valence and Rydberg orbitals

A previously proposed procedure for generating approximate valence, Rydberg, and continuum orbitals from spectral data is extended to two-valence electron systems. Oscillator strengths and photoionization cross sections are reported for the respective 1s²2s² →1s²2s np and 1s²2s²→1s²2s ep transitions of Be, B⁺, C⁺⁺, N⁺⁺⁺, 0⁺⁴, Ne⁺⁶, Mg⁺⁸, Al⁺⁹, and Si⁺¹⁰. Comparisons show a high level of agreement with Hartree-Fock oscillator strengths, but the accuracy of the cross sections is uncertain.     

Sc+18离子的跃迁能和振子强度

用全实加关联方法计算了Sc⁺¹⁸离子1s²2s--1s²np (2≤n≤9) 和1s²2p--1s²nd (3≤n ≤9)的跃迁能和振子强度。1s²np和1s²nd 态的精细结构劈裂通过计算自旋-轨道及自旋-其他轨道相互作用算符的期待值加以确定。还得到了这两个里德堡系列的量子亏损（作为能量的函数）。依据三种规范的振子强度公式得到的计算结果相当好的一致。将这些计算结果与量子亏损理论相结合，进一步得到电离阈附近的分立态-分立态跃迁的振子强度和分立态-连续态跃迁的振子强度密度。     

Relativistic calculations of 3s2 1S0-3s3p 1P1 and 3s2 1S0-3s3p 3P1,2 transition probabilities in the Mg isoelectronic sequence

Using the multi-configuration Dirac-Fock self-consistent field method and the relativistic configuration-interaction method,calculations of transition energies,oscillator strengths and rates are performed for the 3s 2 1 S 0-3s3p 1 P 1 spinallowed transition,3s 2 1 S 0-3s3p 3 P 1,2 intercombination and magnetic quadrupole transition in the Mg isoelectronic sequence(Mg I,Al II,Si III,P IV and S V).Electron correlations are treated adequately,including intravalence electron correlations.The influence of the Breit interaction on oscillator strengths and transition energies are investigated.Quantum electrodynamics corrections are added as corrections.The calculation results are found to be in good agreement with the experimental data and other theoretical calculations.