Cs Ⅳ离子4d内壳层激发态衰变过程的相对论理论研究

在相对论多组态Dirac-Fock理论方法基础上,通过系统考 虑电子关联效应和由于内壳层电子激发而导致的电子自旋-轨道波函数的弛豫效应,详细研究了Cs Ⅳ离子的4d内壳层电子激发组态4d95s25p5、辐射末态4d105s25p4及Auger末态4d105s25p3和4d105s15p4的能级结构及各种可能的辐射和Auger衰变过程.获得了与已有的实验结果和相关的半经 验准相对论组态相互作用计算结果相符的辐射跃迁能、振子强度以及线宽,预言了4d95s25p5态的以Auger衰变为主的 Auger电子谱的特 关键词： 内壳层激发态 辐射衰变 Auger衰变     

C Ⅱ离子1s内壳层激发态的结构和衰变特性的理论研究

在相对论多组态Dirac-Fock理论方法基础上,通过系统考虑电子关联效应、弛豫效应以及相对论高阶修正,详细研究了C Ⅱ离子1s-2p光激发形成的内壳层电子激发态（1s2s²2p²和1s2s2p³）、辐射和Auger末态的能级结构以及各种可能的衰变过程.计算了C Ⅱ离子1s内壳层光激发能量、辐射和Auger衰变率及其线宽,进一步由不确定关系推出了这些激发态的能级寿命,并与最新的实验结果和已有的理论结果进行了比较. 关键词： 内壳层激发态 线宽 寿命 多组态Dirac-Fock方法     

壳模型对13N Gamow-Teller跃迁的研究

最近的研究表明¹³N的beta衰变对于Ia型超新星爆炸前的电子丰度有着重要的影响.本文在壳模型的基础上,首先计算¹³N基态到基态以及基态到不同激发态的Gamow-Teller(GT)跃迁强度,并将其与实验数据进行了比较.在理论计算的GT强度基础上,对不同温度和密度天体环境下¹³N的电子俘获率进行了细致的计算,并重点讨论基态到激发态的GT跃迁对电子俘获率变化的影响.结果表明,考虑基态到激发态的跃迁后,超新星的电子丰度下降,中微子能量损失增大.基态到激发态跃迁对电子俘获率的影响主要由低激发能级贡献. 关键词： Gamow-Teller跃迁 壳模型 电子俘获 激发态     

等离子体屏蔽效应对类氢离子能级结构和辐射跃迁性质的影响

在Debye-Hückel屏蔽近似下,基于相对论Dirac-Fock方法,发展了包括等离子体屏蔽效应的自洽场计算程序.使用该程序研究了等离子体屏蔽效应对类氢离子能级结构和辐射跃迁性质的影响.结果表明,当原子处于等离子体环境中,所有束缚态能级向连续态移动, 移动量随着屏蔽长度的减小而增大.振子强度随屏蔽长度的变化也表现出了相同的规律.进一步分析了相对论效应和等离子体屏蔽效应的耦合,发现对于中Z元素,相对论效应和等离子体屏蔽效应存在较强的耦合.讨论了等离子体屏蔽效应对原子精细结构能级的影响.计算发现,由于等离子体屏蔽效应,原子的能级次序发生了变化,κ简并被消除. 关键词： 等离子体屏蔽 Debye-Hückel 模型 能级结构 跃迁概率     

氦原子单激发和双激发态里德伯系列的相对论能量计算

采用Rayleigh-Ritz变分方法和组态相互作用方法，并进一步考虑相对论修正和质量极化效应，研究了氦原子单激发和双激发态里德伯系列的相对论能量，计算结果与其他理论和实验符合得很好.此外，还计算了该系统之间的振子强度、辐射跃迁率及跃迁波长，振子强度三个规范的计算结果显示出很好的一致性. 关键词： 氦原子 变分计算 振子强度 辐射跃迁率     

CO电子基态P线系跃迁谱线的理论研究

基于微分的思想,结合经典的双原子分子跃迁谱线表达式,提出了预言双原子分子P线系高激发振-转跃迁谱线的新解析物理公式.对于某分子电子体系的某一P支跃迁带,利用实验上获得的一组(15条)精确的跃迁谱线和该跃迁带对应的上下振动态的转动常数(B_υ',B_υ″)的精确数据,该公式不仅可以精确地重复已知的实验跃迁谱线,而且还能预测出实验上难以获得的更高激发态的跃迁谱线数据.利用该公式,研究了CO分子电子基态的(2,0)振-转跃迁带的< 关键词： 双原子分子 发射光谱 P线系')" href="#">P线系 CO     

类氖离子中的能级交叉及其对辐射光谱的影响

本文利用基于相对论多组态Dirc-Fock理论方法的程序包GRASP92以及新近发展的计算辐射跃迁的程序REOSS99，通过对电子关联效应、驰豫效应的系统考虑，计算了类氖等电子系列 (Z=21-92) 离子2p6, 2p53l, 2s2p63l(l=0,1,2)的能级结构和各能级间E1跃迁的波长以及跃迁几率；基于以上计算，详细研究了由于强组态相互作用引起的具有相同宇称和总角动量的能级间的交叉现象及其强组态相互作用对辐射跃迁几率的影响。     

高离化态类镍离子电子碰撞激发过程的相对论扭曲波理论研究

利用相对论扭曲波方法和新发展的研究电子碰撞激发过程的计算程序REIE06,系统计算了电子碰撞激发高离化态类镍Gd³⁶⁺和Rn⁵⁸⁺—U⁶⁴⁺(Z=86—92)离子从基态到4l(l=s,p,d,f)次壳层精细结构能级的碰撞强度和截面.研究了随等电子系列变化时,从基态到与X射线激光有关的3d⁹4p和3d⁹4d激发态能级的电子碰撞激发截面随Z的变化,讨论了强的组态相互作用对高离化态类镍离子截面的影响.通过对Gd³⁶⁺离子涉及X射线激光跃迁的相关能级电子碰撞激发速率系数的计算,分析了等离子体中电子温度对碰撞过程的影响.同时,目前部分计算结果与以往的理论结果进行了比较,得到了很好的一致性. 关键词： 电子碰撞激发 相对论扭曲波方法 高离化态类镍离子     

高双激发Intershell共振态的辐射和Auger跃迁率

采用Conventional infiguration(简写为CI)方法计算了类氦Ar¹⁶⁺离子高双激发Intershell(n>N)共振态的辐射和Auger跃迁率,并利用超球坐标方法和新量子数_n(K,T)_N^A2s+1L^π来作系统分析。计算结果表明,对A=+1态,Auger过程是主要的,辐射过程仅仅是对给定的多重簇(manifold)中更高的态才有意义。对A=0,-1态,Auger宽度更小。对这些 关键词：     

类锂离子双电子复合过程中辐射光子角分布和极化特性的理论研究

基于多组态Dirac-Fock 方法和密度矩阵理论,本文详细计算了高电荷态类锂离子（26 ≤ Z ≤ 92）KLL 双电子复合过程中,自由电子被共振俘获到中间双激发态1s2s²2p_3/2J = 1 的磁子能级截面以及该双激发态的取向参数,进而得到了此激发态向基态电偶极辐射跃迁1s2s²2p_3/2J = 1→1s²2s²J = 0 所发出光子的角分布和极化度,重点讨论了Breit 相互作用对相关物理量的影响. 研究表明,Breit 相互作用极大地改变了中间双激发态1s2s²2p_3/2J = 1 不同磁子能级的截面,从而导致了随后退激发放出光子的角分布和极化特性的显著变化. 关键词： 角分布和极化特性 多组态Dirac-Fock方法 密度矩阵理论     

Auger and radiative transition probabilities of high Rydberg states

The dependence of the Auger and radiative transition probabilities of high Hydberg states on their principal and orbital quantum numbers n and l is studied. Based on explicit calculations, a simple empirical l-dependence of the gaussian type is obtained, which differs drastically from any of the previously assumed behavior.     

Sequential double Auger decay in atoms: A quantum informatic analysis

We theoretically show that the process of inner-shell photoionization in an atom A, followed by the spontaneous sequential emission of two Auger electrons, produces various kinds of spin-entangled states of three flying electronic qubits. All properties of these states are completely pre-determined by the total spin quantum numbers of the electronic states of four atomic species (i.e., A, A^+∗, A2^+∗, A3+) participating in this process in the Russell-Saunders coupling. These tripartite states are readily characterized experimentally by measuring only energies of the three emitted electrons, without requiring any entanglement witness or other such protocols.     

Theoretical calculation of atomic spectrum for 1s23l4l′ states of beryllium-like ions

Using the saddle-point variation and saddle-point complex-rotation methods, energies, radiative, and Auger rates are calculated for the doubly-excited states 1s²3l4l′ of beryllium-like ions. The total wave function is expanded by the restricted variation method to saturate the functional space and improve the nonrelativistic energy. Relativistic corrections and mass polarization effects are taken into account by the first-order perturbation theory. The partial Auger rates for these states are studied. The calculated Auger electron energies are compared with the experimental results which are observed in high resolution electron spectroscopy. The total radiative rates and the total Auger rates for these doubly-excited states 1s²3l4l′ in the beryllium-like ions are also analyzed along with the increase of atomic number Z. Calculated results show that the total Auger rates are several orders of magnitude larger than the total radiative rates for these low-Z systems.     

The structure of theL 2,3 VV-auger line of silicon and silicon compounds

TheL _2,3 VV Auger transitions of Si, SiO₂, and SiC have been measured and compared with the self-fold electron density of states. The data indicate that Auger matrix effects must be included to explain the structure of the Auger lines. A comparison with soft X-ray measurements of Wiech shows, that the measured Auger line shape is nearly identical with the self-foldK _β emission band. The selection rules for X-ray emission lead then to the conclusion that mostlyp-like valence electrons are involved in the Auger transition. This result indicates the relative importance ofs andp states in Auger transitions which is in accordance with theoretical calculations of Feibelman et al.     

A K-harmonics description of 16O breathing mode

We calculate the properties of the ¹⁶O breathing mode in a K_minK-harmonics calculation. The breathing mode has single particle quantum numbers that are identical to the nucleon quantum numbers in the ground state. We calculate an excitation energy of 27 MeV, and a monopole transition matrix element of 7.21 fm². Six excited monopole states are calculated to be bound in ¹⁶O, with k equal to K_min. These states exhaust 90 % of the isoscalar monopole sum rule. The first excited K_min state, the breathing mode, exhausts 68 % of the isoscalar sum rule.     

Ar^1^6^＋离子双激发态的新量子数描述和跃迁规律

此文采用ＣＩ方法计算了类氦Ａｒ１６＋离子双激发态能级和波函数，并向ＤＥＳＢ（Ｄｏｕｂｌｙ－ｅｘｅｃｉｔｅｄｓｔａｔｅｓｂａｓｉｓ）做投影，求出表征这些双激发态的新量子数Ｋ、Ｔ和Ａ。计算和比较了初态ｎ（ｎ－１，０）ｎ＋１Ｓｅ的辐射和Ａｕｇｅｒ跃迁率，发现辐射跃迁随初态主量子数ｎ的变化是光滑的，而Ａｕｇｅｒ跃迁则随ｎ的变化是不光滑的。     

Quantum-gas model estimate for wide range of superconducting critical temperatures

A quantum mechanical model requiring only strong quantum interaction for a charged particle gas estimates the superconducting transition temperature for wide-ranging states of matter. A general equation is derived which estimates the critical temperatureT _c the energy gap, and the coherence length for the classical metallic superconductors, heavy-electron superconductors, the perovskites, metallic hydrogen, and neutron stars. Estimates forT _c , the coherence length, and the energy gap which are model independent for coupling mechanisms agree well with accepted values for these materials. Estimates are made for threedimensional quasi-two and quasi-one-dimensional states.     

Concentrated Kondo systems

This review considers the experimental and theoretical studies of concentrated Kondo systems (CKS), Kondo lattices, substitutional solid solutions and their transition from Kondo impurity to Kondo lattice, and ‘intermediate valence compounds’ which are, in fact, high T _K CKS (T _K is the Kondo temperature). The anomalous low temperature properties of CKS are related to the formation of the narrow (～k _B T _K) high-amplitude Abrikosov-Suhl resonance E _R in the vicinity of the Fermi level E _F. This resonance is situated exactly at E _F in low T _K CKS with T _K < Δ_CF and near E _F in high T _K CKS with T _K > Δ_CF (Δ_CF is the crystal field splitting). In low T _K ‘j=1/2’ CKS the condition E _R=E _F leads to an increase of the density of states at E _F, which is large enough to induce heavy fermion superconductivity in CeCu₂Si₂, UBe₁₃. We demonstrate that the transition from low T _K (E _R=E _F) to high T _K CKS (E _R≠E _F) might be what was formerly considered as a ‘Kondo-lattice-intermediate valence state’ transition. It appears that in many cases the essentially non-integer valence state of the rare-earth elements in metallic compounds is thermodynamically unstable with respect to a transition to an almost integer valence state, because it realizes the maximum gain in free energy from the Kondo condensation.