带电体的自能系数及其规律的研究

文献上常给出个别特殊形状的带电体的自能公式,对一般带电体自能的特点及规律研究不够.本文先建立带电体自能系数的概念,然后计算几种常见对称带电体的自能和自能系数,由此找到带电体自能系数的定性与半定量的规律.     

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     

Ground state Lamb-shift of heavy hydrogen-like ions: status and perspectives

We present the current status in experimental investigations of the heaviest hydrogen-like systems at the Experimental Storage Ring (ESR) at GSI Darmstadt. Together with the most recent theoretical predictions the present experimental result provides a test of the leading quantum electrodynamical (QED) contributions on a percent level. In addition, the planned future experimental studies and related developments devoted to high-resolution spectroscopy of the ground-state in high-Z hydrogen-like systems are reviewed.     

Tensor hyperpolarizability of the 6 s 19 d1D2 barium rydberg state

Tensor polarizability and tensor hyperpolarizability of the 6s19d¹D₂ Rydberg state of Barium were derived from Stark splittings measured by quantum beat spectroscopy. The hyperpolarizability appearing in the fourth order contribution of the perturbation expansion was expressed in spherical tensor form. Using Coulomb approximation numerical values were calculated which are in fair agreement with experimental results.     

Calculation of photon angular distribution and polarization for radiative recombination for high-charged hydrogen-like ions

In this paper a systematic study is carried out on the angular distribution and polarization of photons emitted following radiative recombination of H-like ions by a non-relativistic dipole approximation. In order to incorporate the screening effect due to inner-shell electrons, a distorted wave approach is used. The dependences of the calculated angular distribution and polarization on the reduced energy and nuclear charge are fitted by the corresponding empirical formulas respectively.     

氢及类氢离子光谱精细结构理论计算的改进

原子光谱数据是研究原子结构的重要参数,氢及类氢离子是原子物理和量子力学研究的理想体系.通过对氢及类氢离子光谱精细结构数据的研究发现,需要对Dirac提出的有关理论公式进行改进.本文在考虑了电子的自旋角动量与轨道角动量的耦合作用后,通过对Bohr理论中的电子运动角动量的修改,推导出单电子体系的电子速度公式,结合对Schr dinger的原子轨道能级表达式相对论效应修正,从而得出本文的氢及类氢离子光谱精细结构值的理论计算公式,应用此改进公式,所得的计算值与实验观测值符合得很好,计算结果也反映了氢及类氢离子光谱精细结构数据变化的规律性.     

Solid state effects on tunneling probability for d+d nuclear fusion at room temperature

Abstract

The tunneling probability for d+d nuclear fusion reaction is calculated, incorporating the screening on the Coulomb potential and effective electron mass in solids. The possibility of cold (room temperature) nuclear fusion is discussed.     

三角对称晶场中6 S(3d5)态离子零场分裂参量的微观起源

基于完全对角化方法(complete diagonalization method, CDM), 研究了⁶ S(3d⁵)态离子在三角晶场(包括C_3v,D₃,D_3d点群对称晶场)中零场分裂(zero-field splitting, ZFS)参量D和(a-F)的微观起源.研究中除了考虑研究者通常考虑的SO(spin-orbit)磁相互作用外,同 关键词： 6 S(3d⁵)态离子')" href="#">⁶ S(3d⁵)态离子 零场分裂参量 磁相互作用 完全对角化方法     

晶体材料中3d2态离子自旋哈密顿参量的微观起源

采用了中间场耦合图像，考虑了以前研究中被忽略的SS (spin-spin)磁相互作用以及SOO (spin-other-orbit)磁相互作用，利用完全对角化方法，研究了3d₂态离子在三角对称 (C_3v, D₃, D_3d)晶体中自旋哈密顿(SH)参量的微观起源.发现自旋哈密顿参量 (包括零场分裂参量D和g因子g∥,g⊥)来自四种耦合机理：（1）SO (spin-orbit)耦合机理; (2) SS耦合机理；（3）SOO 关键词： 自旋哈密顿参量 2态离子')" href="#">3d₂态离子 三角对称晶场 SS与SOO作用 SO-SS-SOO联合作用机理     

Experimentally determined transition probabilities of the systems 6p2→6p6d, 6p7s, 6p8s of neutral lead

Branching ratio measurements have been performed for all of the observed transitions from eight levels in neutral lead (6p²→6p6d, 6p²→ 6p7s, 6p²→6p8s) excited in a hollow cathode discharge in the 200–730 nm spectral range. From the relative emission intensity data, a set of absolute transition probabilities is derived for 28 lines, including lines for which transition probabilities have not been previously published. The absolute scales are obtained by averaging the measured lifetimes of the ³P⁰_1,2, ¹P_1⁰(6p7s), ³F^0_2,3, ³D^0_1,2(6p6d) levels.     

原子核的有限体积效应对高离化态离子能级和波函数的影响

在相对论理论框架下,分别在点电荷和两参数Fermi核模型近似下计算了高离化态类氢离子（Z=80—112）n=1—3壳层的波函数和能级. 分析了核有限体积效应对它们的影响. 在此基础上,给出了核有限体积效应对原子能级的修正公式. 同时,还进一步讨论了相对论效应和核有限体积效应之间的相互影响,发现对高Z元素相对论效应与核有限体积效应之间有很强的耦合. 关键词： 原子核有限体积效应 高离化态离子 相对论效应     

类铍离子1s~22snp~3P(n=2～6,Z=5～8)态能级和精细结构参数的理论计算

在准相对论框架下,以多电子原子精细结构哈密顿的球张量形式为基础,借助不可约张量和角动量耦合理论,导出类铍离子1s22snp(n=2-6)3P态精细结构(包括自旋-轨道相互作用、自旋-其它轨道相互作用和自旋-自旋相互作用)和精细结构参数的解析表达式,并利用我们所开发的程序,对各项进行了具体地计算,计算结果与文献符合地较好.     

三角对称下3d3离子2E态g因子性质研究

采用完全对角化方法,以尖晶石结构的ZnAl2O4:Cr3+,ZnGa2O4:Cr3+和MgAl2O4:Cr3+系列晶体为例,联系晶格局域结构,对三角对称下3d3离子2E态g因子性质进行了研究.研究中考虑了包括自旋与自旋相互作用、自旋与另一轨道相互作用以及轨道与轨道相互作用在内的微小磁相互作用.对ZnAl2O4:Cr3+ 体系2E态g因子给出了理论解释,说明了ZnGa2O4:Cr3+体系的g‖(E′)应为负值,并从理论上预测了MgAl2O4:Cr3+体系2E态g因子数值.研究表明,微小磁相互作用对2E态g因子的贡献较大,在计算中是不可忽略的;相对于基态g因子来说,2E态g因子随晶格局域结构变化较为敏感.     

The measurement of the electronic g-factor in hydrogen-like ions --A promising tool for determining fundamental and nuclear constants

We describe a double-Penning-trap experiment suitable for testing QED in strong fields by determining the electronic g-factor of a single hydrogen-like ion in its ground state. Our measurements on ¹²C^{5 +} reach a relative accuracy of 2×10^-9, where the largest uncertainty results from the mass of the electron. Together with equally precise theoretical predictions therefore, it is possible to evaluate a new value for the electron's mass. The possibilities to obtain other fundamental constants and nuclear parameters are lined out. Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002 RID="a" ID="a"e-mail: t.beier@gsi.de     

Hyperfine structure in the 6p5d configuration and isotope shifts in transitions between the 6s5d and the 6p5d configurations in Ba I

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.     

碱金属原子和类氢离子束缚态能级的解析解

对于碱金属原子和类氢离子的原子实模型,从物理实质图像和极化与贯穿作用的量化及实验资料入手深入地进行了分析,引入了半经验碱金属和类氢原子内部相互作用势,建立了定态薛定谔方程.运用微扰理论获得能级Enl,并进一步导出了有效主量子数、有效核电荷数等重要参数.这对物质化学特性和原子特性研究是有益的.     

On electron screening effects in the low-energy 3He(d,p)4He data

We have calculated the screening effects of the two electrons in the atomic ³He gas target on the low-energy³He(d, p)⁴He data. The nuclear degrees of freedom have been described within the microscopic multi-channel Resonating Group Method, while the two electrons have been treated in Born-Oppenheimer approximation deriving the exact screening potential within the Path Integral Monte Carlo method. Our model underestimates the observed screening effects implying the need to consider the coupling of nuclear and electronic degrees of freedom.     

核电荷分布对类氢原子基态能量计算的影响

在高斯型核电荷分布模型中,分别采用基于B样条的Notre Dame和Dual-Kinetic-Balance基组求解类氢体系的Dirac方程。通过对所得的基态能量和点电荷分布模型的结果以及实验测量值进行比较,发现核电荷分布效应对结果具有重要影响,其相对修正随原子序数Z的增加而逐渐显著。当Z=100时,相对修正能达到10^−3。并在近核区域给出了两种模型下计算的波函数。当Z增加时,波函数的差别也逐渐明显。不同于其他将B样条应用于电子与原子核的长程相互作用计算的工作,此工作成功地将B 样条方法推广到了短程相互作用的研究。     

核电荷分布对类氢原子基态能量计算的影响

在高斯型核电荷分布模型中,分别采用基于B样条的Notre Dame和Dual-Kinetic-Balance基组求解类氢体系的Dirac方程。通过对所得的基态能量和点电荷分布模型的结果以及实验测量值进行比较,发现核电荷分布效应对结果具有重要影响,其相对修正随原子序数Z的增加而逐渐显著。当Z=100时,相对修正能达到10^−3。并在近核区域给出了两种模型下计算的波函数。当Z增加时,波函数的差别也逐渐明显。不同于其他将B样条应用于电子与原子核的长程相互作用计算的工作,此工作成功地将B 样条方法推广到了短程相互作用的研究。