Effect of Wave-Function Mixing in Antiprotonic Helium

The effect of wave-function mixing in antiprotonic helium is discussed. This effect manifests itself in a considerable change of the Auger decay rate of long-lived states of ^3,4He e. Properties of short-lived states which influence the decay rate of long-lived ones are described. It is proposed to observe these short-lived states in a direct experiment. This revised version was published online in August 2006 with corrections to the Cover Date.     

Metastable States in Antiprotonic Helium Atoms: An Island of Stability in a Sea of Continuum

 In this contribution we consider a phenomenon of metastable states in antiprotonic helium atoms, precise spectroscopy of these states and a present-day study of the electromagnetic properties of antiprotons. Received October 16, 2001; accepted for publication November 13, 2001     

High-Precision Calculation of the Fine and Hyperfine Structure Splittings of Antiprotonic Helium-3,4 Atoms

Hyperfine Interactions - In this work we explore electrochemical-polishing for thinning Fe-Mn samples. We set out by studying with CEMS and XCMS a sample approximately 1 mm thick of a bcc Fe-13.7...     

Energy Spectrum of Helium Confined to a Two-Dimensional Space

Making use of the adiabatic hyperspherical approach, we report a calculation for the energy spectrum of the ground and low-excited states of a two-dimensional helium in a magnetic field. The results show that the ground and low-excited states of helium in low-dimensional space are more stable than those in three-dimensional space and there may exist more bound states.     

A Study of Confined Helium Atom

The helium atom confined by a spherical parabolic potential well is studied employing the adiabatic hyperspherical approach method. Total energies of the ground and three low-excited states are obtained as a function of the confined potential radii. We find that the energies of a spherical parabolic potential well are in good agreement with those of an impenetrable spherical box for the larger confined potential radius. We find also that the confinement may cause accidental degeneracies between levels with different low-excited states and the inversion of the energy values. The results for the three-dimensional spherical potential well and the two-dimensional disc-like potential well are compared with each other. We find that the energy difference between states in a two-dimensional parabolic potential is also obviously larger than the corresponding levels for a spherical parabolic potential.     

Calculation of Excited States of He Atoms in a Strong Magnetic Field

A recently developed B-spline algorithm is extended and utilized to calculate excited states of He atoms in the presence of strong magnetic fields. Binding energies are presented for He in the five excited atomic states 2¹0⁺, 1¹0^-, 2¹0^-, 1¹(-1)⁺, and 2¹(-1)⁺ with magnetic field strength ranging from 0.0001 to 10 a.u. The obtained energies are compared with available theoretical data, and found to be in good agreement. We investigate influence of magnetic fields on atomic structures of multielectron atoms, and illustrate that how electron probability density distributions change with increasing magnetic field strength. The current approach is directly applicable to simulations of discrete spectra for He atoms in the atmospheres of magnetized white dwarf stars.     

Calculation of Energy and Other Properties of Muonic Helium Atom Using Boundary Conditions of Wave Function

The properties of muonic helium atom （^4He＋2μ-e-） in ground state are considered. In this work, the energy and average distance between particles have been obtained using a wave function, which satisfies boundary conditions. It is shown that the obtained energy are very close to the values calculated by others. But the small differences of the expectation values of r^2n are due to the incorporated boundary conditions in proposed wave function and are expected.     

Calculation of Energy and Other Properties of Muonic Helium Atom Using Boundary Conditions of Wave Function

The properties of muonic helium atom (⁴He⁺²μ^-e^-) in ground state are considered. In this work, the energy and average distance between particles have been obtained using a wave function, which satisfies boundary conditions. It is shown that the obtained energy are very close to the values calculated by others. But the small differences of the expectation values of r²ⁿare due to the incorporated boundary conditions in proposed wave function and are expected.     

氦原子基态的斯塔克效应

用微扰与变分相结合的方法计算了氦原子基态的斯塔克效应,通过计算发现这种方法简便直观,尤其适用于低激发态且电子数不太多的原子．     

Kinetics of the Excited States of Helium in an Atmospheric-Pressure Glow Discharge in a Helium-Nitrogen Mixture

Using an atomic-absorption spectral analysis technique, we determined the concentrations of helium atoms in states 2¹S, 2¹P, 2³S, and 2³P in an atmospheric-pressure glow discharge in helium (99.98%) and in a mixture of helium with nitrogen (99.5%He+0.5%N₂). It is shown that the population of the lower excited levels of helium atoms (n = 2) in its mixture with nitrogen is almost an order of magnitude smaller than in the case of a discharge in helium. The maximum of the concentration of excited atoms in a discharge both in helium and in its mixture with nitrogen is in the cathode region at a distance of about 0.1 mm from the cathode. The reaction of quenching of excited helium atoms by nitrogen molecules is responsible for the sharp decrease in the concentration of He(n = 2) on addition of nitrogen into helium. Presented at the 5th Symposium on Physics and Diagnostics of Laboratory and Astrophysical Plasmas, Belarus, Serbia and Montenegro, Minsk, Belarus, September 20–23, 2004; 12th International Congress on Plasma Physics, October 25–29, 2004, Nice, France. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 4, pp. 530–537, July–August, 2005.     

氦原子低激发态能量的变分计算

给出了一种用变分法计算氦原子低激发态（电子组态为1s2s,1s2p)能量的具体方法,计算过程中解决了激发态波函数与基态波函数的正交性,计算结果与实验值与相当接近。     

低损耗玻璃光波导的溶胶-凝胶法制备

By means of the relation of ionicity and the ionization energies of hydrogenlike atoms, the soft X-ray spectra are calculated for the hydrogenlike sodium, magnesium and aluminium atoms. The calculated results are in good agreement with the experiments.     

Calculations of the Energies of the Excited States of Open-Shell Atoms in the Hartree-Fock Approximation

In the framework of the Roothaan-Hartree-Fock atomic theory, the solution of a many-electron problem is considered on the basis of the methods of minimizing a function of many variables. To implement this approach, expressions are obtained for the energy derivatives with respect to the elements of density matrices and the nonlinear parameters of atomic orbitals, that is, orbital exponents. Using the first- and second-order minimization methods, we performed optimization of the orbital exponents of Slater-type atomic orbitals for atoms and ions with several open shells. For them, energies that are close to the data of the numerical solution of the Hartree-Fock equations at a high accuracy of the virial ratio were determined. For a number of atoms the frequencies of the first dipole transitions were calculated, and the results were compared to the data obtained in calculation by the method of random phases and to experimental data. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 3, pp. 292–300, May–June, 2005.     

Calculation of Soft X ray Spectra of Hydrogenlike Sodium, Magnesium and Aluminium Atoms

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铯原子高激发态Stark能级的数值计算和实验观察

利用数值方法计算了铯原子的Stark结构,经过对氢原子的数值计算与解析结果的对比,确认我们的计算程序是精确的.实验工作在超冷铯原子中完成,利用共振增强多光子电离光谱方法测量了铯原子n=16附近的Stark光谱,理论计算和实验结果相一致.     

超冷V型三能级原子注入的微脉塞的光谱性质

建立了超冷V型三能级原子注入的微脉塞的量子理论。首先推导出腔场约化密度算符随时间演化的主方程,并由此出发着重研究了微脉塞腔场的光谱性质。结果表明,与用超冷二能级原子或用热的二能级和三能级原子注入的微脉塞的光谱相比,用超冷V型三能级原子注入的微脉塞具有新的光谱性质,对某些腔长,线宽可被突然加宽,腔场也发生大的频移,不同的原子相干性甚至可以使腔场频率发生方向相反的频移。另一方面,原子质心动量对光谱也有影响,表现在线宽和频移随质心动量减小而减小。     

产生于能量积聚效应的钠原子高激发态碰撞转移速率的功率效应

报道了用连续单模激光器将Na原子共振激发至3P态,观察到通过Na(3P)-Na(3P)能量积聚碰撞过程布居的高激发态荧光随激发光功率的变化关系。根据碰撞转移模型运用近似二能级系统下的速率方程对实验结果作了解释,理论分析与实验数据相结合得到了高激发态的碰撞转移速率k4D,k5P,k4P,k5S随激发光功率增长的变化特性。     

用DIS数字化信息系统测定氦气的摩尔质量

基于DIS数字化信息系统平台,利用牛顿运动定律、阿基米德原理、理想气体状态方程和物质的摩尔质量等相关知识,对氦气的摩尔质量进行实验测定.     

用玻尔理论统-处理氢原子、电子偶素和氦原子基态能级

用玻尔氢原子理论处理氢原子和电子偶素基态的方法，在假定了氦原子基态的经典模型后，给出了氦原子基态能级和半径，并与实验和量子力学变分法计算的结果作比较，说明玻尔氢原子理论对氦原子基态能级的计算有一定的意义．