Low pressure broadening and shift of the 2p 53p-2p 56s neon spectral lines

Natural radiative lifetimes in the perturbed 6s n s ¹ D ₂ (n=12?30) sequence of barium have been measured using the PUMOLS (PUlse-MOdulated Laser Spectroscopy) method, which incorporates pulse-modulation of a CW dye-laser beam and delayed coincidence techniques. Principal perturbers are the 5d 7d ³ F ₂ and¹ D ₂ states. Lifetimes were also measured for these shortlived valence states, which through configuration mixing cause drastic decreases in lifetime values in the region of perturbation of the 6s n d ¹ D ₂ sequence. Two-step laser excitation from the ground 6s ^{2 1} S ₀ state via the 6s 6p ¹ P ₁ state was employed. Special care was taken to determine the influence of black-body radiation transitions on the measured lifetimes.     

Strong Relaxation and Correlation Effects on the 2p 53s–2p 6 Spectrum of Neutral Neon

Hyperfine Interactions - The effects of correlation and relaxation on the 2p 53s?1,3 P 1–2p 6?1 S 0 resonance and intercombination transitions of neutral neon have been studied...     

Some perturbation calculations for 1s2p, 1s 22p,and 1s 22s

The Dalgarno interchange theorem is used, together with the U function approach, to evaluate the first order perturbation corrections to <r ₁ ^-1+r ₂ ^-1> and <r ₁ + r ₂> for the two-electron states 1s2p ¹ P and 1s2p ³ P. The results for <r ₁ + r ₂> are extended by using a screening approximation, and are compared with the results of accurate variational calculations. The first order perturbation correction to spin-weighted expectation values of type <ΣV(r_j )s_zj > is given for the three-electron states 1s ²2p ² P and 1s ²2s ² S. The case V(r_j ) = r _j ^-1 is treated in detail.     

Electric-dipole oscillator strengths of 2p 63s 2 S e →2p 53s 2 2 P 0 transition in MgII,Al III and SiIV ions of the NaI isoelectronic sequence

Summary Electric-dipole oscillator strengths, of both the length and velocity forms, for the inner-shell excitation 1s ²2s ²2p ⁶3s ² S ^e →1s ²2s ²2p ⁵3s ^{2 2} P ⁰ transition, which leads to autoionization (Auger transition), in Mg II, Al III and SiIV ions of the sodium isoelectronic sequence have been calculated using the approach suggested by one of us (Tiwary) in the case of the Fe¹⁵⁺ ion. Our present calculated results demonstrate that the Tiwary approach is capable of yielding encouraging results. A part of this work was done while the author was Research Director and Professor, CNRS Laboratory, University of Paris-Sud, Paris and Obsevatoire de Paris, Meudon, Paris, France.     

类锂“洞原子”2s2s2p2P0和2s2p2p2D三激发共振系列的能量、精细结构和寿命

采用多通道鞍点和鞍点复数转动方法，计算了类锂离子(Z=3—10)2s2s2p²P⁰和2s2p2p²D三激发共振态系列的能量、精细结构和寿命.Auger宽度由耦合主要的通道得到，相对论效应计算到一级微扰，质量极化效应计算到无穷级. 关键词：     

弛豫与关联效应对NII离子2s22p3s3P1—2s22p21D2与2s22p3s1P1—2s22p23P0,1,2自旋禁戒跃迁概率的影响

用多组态Dirac-Fock方法，并系统考虑相对论效应、电子关联、弛豫效应等重要贡献，计算了NII离子2s22p3s 3P1—2s22p21D2和2s22p3s 1P1—2s22p23P0,1,2自旋禁戒跃迁概率和振子强度-通过比较计算证实：弛豫和关联效应对禁戒跃迁概率的影响非常大，考虑了这些效应后，计算结果有显著的改善-由跃迁概率和振子强度的计算值推断，2s22p3s 3P1—2s22p21D2的谱线强度应该比原有的理论预言值小- 关键词： 跃迁概率 多组态Dirac-Fock方法     

Observation of fine structure in the 1s2s2p P-1s2p S transition of core-excited O V

We have measured the absolute wavelengths of the fine structure components of the 1s2s2p^{2 5}P-1s2p^{3 5}S transition in beryllium-like oxygen using the method of fast ion spectroscopy. These results represent the first measurement of fine structure in any core-excited 4-electron ion. We have also measured the lifetime of the metastable 1s2p^{3 5}S state. The structure and lifetime results are compared with recent relativistic MCHF calculations.     

Photoionization of Al IV (neon-type) from its ground 2s 22p 6 1 S e and excited 2s 22p 53p 3,1 P 0 3 S e states using the R-matrix method

The R-matrix method is used to calculate the total photoionization cross-sections from the ground 2s ²2p ^{6 1} S ^e and the first three excited 2s ²2p ⁵3p ^3,1 S ^e states of Al IV, for photon energies ranging from the first ionization threshold to just above the second threshold of the residual ion Al V. The two lowest LS terms of Al V − 2s ²2p ^{5 2} P ⁰, 2s2p ^{6 2} S ^e, 2s2p ^{6 2} S ^e, represented by sophisticated configuration interaction wavefunctions, are included in the R-matrix calculation. The resulting cross-sections are affected by Rydberg series of resonances converging to the 2s2p ^{6 2} S ^e excited threshold.     

类镓等电子序列ZrX—RhXV离子的4s^24p—4s^24d,4s^24p—4s4p^2,4s^24 …

本文对类镓等电子序列ＧａＩ－ＸｅＸＸＩＶ离子４ｓ＾２４ｐ、４ｓ＾２４ｐ、４ｓ＾２４ｄ、４ｓ４ｐ＾２、４ｐ＾３和４ｓ＾２５ｓ组态组级结果和组态相互作用了理论分析，找出沿等电子序列的变化规律。     

类铍离子1s22s2p 3P1, 2 能级之间的磁偶极跃迁

用多组态Dirac-Fock和相对论组态相互作用的扩展优化能级方法,在计算中包含了Breit相互作用,真空极化,自能以及有限核质量修正,计算了核电荷数从Z=6到80的类铍离子等电子序列的1s22s2p 3P1, 2的精细结构能级,磁偶极跃迁几率和振子强度。结果与目前可靠的结果在其不确定度范围内符合得很好,另外也得到一些与其他早期理论计算不同的结果。     

Relativistic electron correlation, quantum electrodynamics, and the lifetime of the 1s(2)2s(2)2p2p0(3/2) level in boronlike argon

The lifetime of the Ar13+ 1s(2)2s(2)2p2p0(3/2) metastable level was determined at the Heidelberg Electron Beam Ion Trap to be 9.573(4)(5). The accuracy level of one per thousand makes this measurement sensitive to quantum electrodynamic effects like the electron anomalous magnetic moment (EAMM) and to relativistic electron-electron correlation effects like the frequency-dependent Breit interaction. Theoretical predictions, adjusted for the EAMM, cluster about a lifetime that is approximately shorter than our experimental result.     

Spin-forbidden transitions between 2p 2 and 2s2p states in the beryllium isoelectronic sequence

Fine-structure splittings, wavelengths and transition probabilities are evaluated for transitions 2p ^{2 1} S ₀→2s2p ³ P ₁ ⁰, 2p ^{2 1} D ₂→2s2p ³ P _J ⁰ (J=1, 2) and 2p ^{2 3} P _J →2s2p ¹ P ₁ ⁰ (J =0, 1, 2) in beryllium-like ions using configuration interaction wavefunctions. Some significant differences with previous calculations are obtained. At present there are no experimental results. However, from calculations reported here it should clearly be worthwhile to search for these lines in laboratory and astrophysical spectra. The decay of the 2p ^{2 1} D ₂ level is discussed.     

类锂等电子系列(1s2p2p)~4 P~e和(1s2s2p)~4 P~0态的能量和精细结构研究

利用改进的马鞍点方法,截断变分方法,并考虑能量的相对论修正和质量极化效应,计算和研究了类理等电子系列的两个四重态（１ｓ２ｐ２ｐ）４Ｐ０和（１ｓ２ｓ２ｐ）４Ｐｅ态的精细结构和平均跃迁波长,并与实验和其它理论计算结果进行了比较。     

延迟和相关效应对Ne原子2p53s1,3P01-2p61S0跃迁的影响

利用多组态Dirac-Fock(MCDF)方法,系统地研究了延迟和相关效应对中性Ne原子2p53s1,3P01-2p61S0电偶极共振和复合跃迁的能量以及跃迁几率(寿命)的影响,给出了相应的跃迁能和辐射寿命,并与最新的实验观测和其他理论计算结果进行了比较.     

Studying Li and He− in the 1s2s2p configuration

Expressions are derived for the nonrelativistic energy of the 1s2s2p configuration. In both the possible electron momentum binding systems (1s2s)2p and 1s(2s2p) values are determined for the parameters of the generalized hydrogenlike analytical radial orbitals for a lithium atom and a negative helium ion. The Li and He^– energy spectra in the 1s2s2p configuration are compared with the theoretical calculations of other authors and with experimental data.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 70–74, June, 1977.     

类锂离子2s2p2p^2S三激发态的能量和宽度

采用马鞍点变分方法和复数转动技术，计算了类锂离子２ｓ２ｐ２ｐ２Ｓ三激发共振态的能量，并运用截断变分方法得到能量改进量，以及计算了相对论效应、质量极化效应，从而获得了高精度的能量计算值。还计算了该系统的Ａｕｇｅｒ宽度，位移和辐射跃迁率。     

LiⅠ等电子序列[(1s2p)3P,4d]2P0及 [(1s2s)1S,5p]2P0自电离态的计算

利用鞍点复转动及全实加关联的方法,计算了LiⅠ等电子序列[(1s2p)3P,4d]2P0及[(1s2s)1S,5p]2P0自电离态的能量和宽度.计算结果中包括相对论修正和质量极化修正.文中讨论了自电离宽度随核电荷数Z的变化关系,同时也讨论了精细结构分裂值及相对论修正随核电荷数Z的变化关系.     

延迟和相关效应对Ne原子2p53s1,3P10-2p6 1S0跃迁的影响

利用多组态Dirac-Fock(MCDF)方法,系统地研究了延迟和相关效应对中性Ne原子2p53s1,3P01-2p61S0电偶极共振和复合跃迁的能量以及跃迁几率(寿命)的影响,给出了相应的跃迁能和辐射寿命,并与最新的实验观测和其他理论计算结果进行了比较.