核极化对Rydberg原子能级寿命的影响

在不依赖实验参数的较为严格的算法基础上,考虑了Rydberg电子与原子实间的相互作用,在计算中势函数增加了极化势,并对偶极跃迁进行了修正.用此方法计算了Li原子的s态和d态的能级寿命,结果较好地符合了实验值.     

硼原子高Rydberg态能级研究

利用最弱受约束电子势模型理论,通过对最弱受约束电子的识别,将Martin公式推广到了多电子原子系统.依此研究了B原子的2s2np(n≥30)系列Rydberg能级,理论计算值与实验值吻合较好,二者的相对误差小于6.59×10-5,达到了很高的精度.     

超冷铯Rydberg原子寿命的测量

本文从实验上采用两步激发超冷基态原子获得超冷Rydberg原子,通过选择场电离的方法获得超冷Rydberg原子的离子信号.改变延迟时间测得Rydberg原子布居数随时间的变化关系,用两种方法拟合实验数据得到36D和34S态原子的有效寿命,与现有理论结果一致. 关键词： Rydberg原子 寿命 黑体辐射 场电离     

铅原子奇宇称Rydberg系列寿命的研究

在多通道量子数亏损理论(MQDT)的基础上,利用已给出的用MQDT波函数统一计算高激发态寿命的方法,计算并预言了J=1奇宇称两个Rydberg系列的寿命,在利用MQDT计算时,确定了6p6d3/2[3/2]₁⁰的能级位置.     

汞原子6sns 3S1,6snd 3D1 Rydberg系列的寿命

利用多通道量子数亏损理论计算了汞原子6sns^3S1(n=11～25),6snd^3D1(n=12～24)两个Rydberg系列的能级和寿命,给出了这两个系列寿命所遵循的公式,6sns^3S。系列为r=0．814v^2.835(ns),6snd^3D1系列为r=0．302v^2.926ns),其中v为有效量子数。     

铕原子Rydberg态的场电离研究

利用三步激光共振激发结合场电离探测技术,系统地研究了铕原子归属于第一电离限4f76s 9S4的4f76snp Rydberg态的场电离过程,得到了铕原子4f76snp Rydberg 态的场电离光谱图。在光激发之后施加脉宽为0.2μs的脉冲电场,连续扫描电压得到场电离过程图。从4f76snp Rydberg态的场电离过程图谱中,可以精确地获得态的场电离阈,观察电场逐步从0到3 kV变化时原子的演化过程。特别是,受黑体辐射的影响,一些结构出现在了场电离光谱图上。     

超冷nS Rydberg原子的态转移

本文从实验上研究了超冷nS Rydberg原子在外电场脉冲作用下的态转移现象. 采用双光子激发超冷基态原子制备超冷Rydberg原子, 通过脉冲场电离法探测超冷Rydberg原子的离子信号, 实验研究了由外加脉冲电场产生的nS能级和多重态的避免交叉, 获得了在外电场脉冲作用下nS态原子的态转移现象, 实验与理论计算的结果相一致. 关键词： Rydberg原子 态转移 能级避免交叉     

氦原子Rydberg态10G—10M磁精细结构的计算

通过自洽迭代求解Hartree方程，得到了氦原子1snl组态下的严格数值解波函数，以此构造LS耦合谱项(支项)波函数作为基矢.采用线性变分法，同时考虑交换作用和Breit-Bethe近似下的磁相互作用项，计算了氦Rydberg态10G—10M系列能级的磁精细结构，计算结果很好地符合已有的实验值.对计算方法的进一步改进提出了设想和讨论. 关键词： 氦原子 Rydberg态 磁精细结构 自洽迭代     

WBEPM理论下锡原子受扰Rydberg系列能级和量子数亏损计算

在最弱受约束电子势模型理论下,通过研究量子数亏损 与 之间的变化规律,确定了SnⅠ原子的 和 两个系列的六个外来微扰谱项的能级.在考虑了这些外来微扰项影响的基础上,计算了这两个受扰Rydberg系列的量子数亏损与能级.计算结果与实验值符合较好,相对误差小于3.63E-05,达到了很高的精确度,依此外推的能级数据具有较高的可信度.     

锂原子里德伯态能级的精细结构分裂

对锂原子的四体问题的哈密顿算符进行幂级数展开,通过计算原子实的 极化(包括偶极矩,四极矩至八级电极矩)对能级的贡献,同时考虑相对论效应和LS耦合以 及有效势的高阶修正,求得了锂原子里德伯态的能级位移和能级公式。用此公式计算N=5～1 2,L=4～9,J=L±1/2的相关的精细结构位移以及能级间隔,并与有关实验结果进行了比较 。     

Calculation of the fine structure of the level in Rydberg state of lithium

The level shift and level formula of lithium atom in Rydberg states are achieved by means of the calculation of polarization of the atomic core (including the contribution of dipole moment, quadrupole moment and octupole moment);meanwhile, the effect of relativity theory, the orbital angular momentum L and the spin angular momentum S coupling (LS coupling), and high order correction of the effective potential are considered. The some fine structures (N=5～12,L=4～9,J=L±1/2) and the corresponding level intervals in Rydberg states can be calculated by the above-mentioned level formula and compared with correlated experimental data.     

Calculation of the fine structure of the level in Rydberg state of lithium

The level shift and level formula of lithium atom in Rydberg states are achieved by means of the calculation of polarization of the atomic core （including the contribution of dipole moment, quadrupole moment and octupole moment） ; meanwhile, the effect of relativity theory, the orbital angular momentum L and the spin angular momentum S coupling （IS coupling）, and high order correction of the effective potential are considered. Thesome fine structures （N = 5- 12, L = 4-9, J = L ± 1/2） and the corresponding level intervals in Rydberg statescan be calculated by the above-mentioned level formula and compared with correlated experimental data.     

The fine structure splitting of the level of lithium in Rydberg states

The Hamiltonian of the four-body problem for a lithium atom is expanded in series. The level shift and level formula of a lithium atom in Rydberg states are achieved by means of the calculation of polarization of the atomic core (including the contribution of dipole, quadrupole and octupole components). We also consider the effect of relativity theory, the orbital angular momentum L and the spin angular momentum S coupling scheme (LS coupling) and high-order correction of the effective potential to the level shift. The fine structure splitting (N=5-12, L=4-9, J=L±1/2) and level intervals in Rydberg states have been calculated by the above-mentioned formula and compared with recent experimental data.     

Na原子高里德堡态的辐射寿命

用可调谐激光两步激发Ｎａ原子高激发发里德堡态布居，在光激发后施加脉冲电场测量激发态的场电离阈，利用阈值电场和延迟场电离方法测定了ｎｓ（ｎ＝２０～２４）和ｎｄ（ｎ＝１９～２３）态的寿命值，并与计算值进行了比较，对影响寿命的因素作了讨论。     

Radiative lifetimes of Rydberg 6pnd J=2 states of Pb I by multichannel quantum defect theory

Energy levels of the odd-parity 6pnd J=2 Rydberg states of Pb I are analysed by the multichannel quantum defect theory (MQDT) in the frame of a five-channel three-limit calculation model. With optimal MQDT parameters, channel admixture coefficients are obtained and used to calculate the theoretical lifetimes of the levels by comparing to the previously measured lifetimes. The predicted lifetimes for higher-lying Rydberg states are given and discussed. These predicted lifetimes are very different from those obtained by the four-channel two-limit model pl:eviously used, which means that introduction of the additional interacting channel is important for studying the 6pnd J=2 Rydberg states of Pb I.     

Experimental study of bound and autoionizing Rydberg states of the europium atom

An isolated-core-excitation (ICE) scheme and stepwise excitation are employed to study the highly excited states of the europium atom. The bound europium spectrum with odd parity in a region of 42400--43500~cm^{ - 1} is measured, from which spectral information on 38 transitions, such as level position and relative intensity, can be deduced. Combined with information about excitation calibration and the error estimation process, the selection rules enable us to determine the possible values of total angular momentum J for the observed states. The autoionization spectra of atomic europium, belonging to the 4f^{7}6p{nl} (l=0, 2) configurations, are systematically investigated by using the three-step laser resonance ionization spectroscopy (RIS) approach. With the ICE scheme, all the experimental spectra of the autoionizing states have nearly symmetric profiles whose peak positions and widths can be easily obtained. A comparison between our results and those from the relevant literature shows that our work not only confirms many reported states, but also discovers 14 bound states and 16 autoionizing states.     

铯原子里德堡态Stark能量及电偶极矩的测量和理论计算

里德堡原子由于具有体积大、寿命长、易极化及在外电场中能级易于操控等特点, 已经成为了目前物理学领域研究的热点之一. 本文在磁光阱中实验测量了铯原子15P_3/2和16P_3/2态的Stark光谱,根据光谱给出了15P_3/2和16P_3/2|m|=1/2 Stark态在0-1400 V/cm场强范围适用的Stark 能量和偶极矩的经验性解析表达式; 用数值方法求解薛定谔方程获得了这些态的Stark能量、偶极矩和电子几率密度分布. 电子几率密度分布定性说明了计算的偶极矩矢量的方向是正确的. 计算的Stark能量、偶极矩与实验结果相一致.     

Spectroscopic properties and radiative lifetimes of SiTe:A high-level multireference configuration interaction investigation

The 18 A-S states correlated to the lowest dissociation limit of SiTe were calculated by using a high-level multirefer-ence configuration interaction （MRCI） method, including scalar relativistic and spin-orbit coupling effects. Based on the calculated potential energy curves, the spectroscopic constants of bound states were determined, which are well consistent with previous experimental results. The spin-orbit matrix elements between the A-S states were computed, which lead to an in-deoth understanding, of oerturbations on the electronic state a^3∏. Finally. the transition dioole moments of allowed transitionsA^1∏-X^1∑^＋,E^1∑^＋-X^1∑^＋,a^3∏-d^3△,a^3∏-d^3△,a^∏-a′^3∑^＋,a^3∏-e^3∑^-,and the radiative lifetimes of A^1∏,E^1∑^＋,and a^3∏ were evaluated.     

Vibronic structure of the 3s Rydberg state of the 2-methylallyl radical

Resonance-enhanced multiphoton ionization combined with electronic ground state depletion spectroscopy of jet-cooled 2-methylallyl (C₄H₇) radicals provides vibronic spectra of the 3s and 3p Rydberg states. Analysis of the vibronic structure following one-photon and two-photon excitation of rovibronically cold 2-methylallyl radicals and its isotopologues C₄H₄D₃ and C₄D₇ reveals transitions to more than 30 vibrational levels in the 3s Rydberg state that are identified and reassigned on the basis of predictions from ab initio calculations and results from pulsed-field-ionization zero-kinetic-energy photoelectron spectra obtained with resonant multiphoton excitation via selected intermediate states. Depletion spectroscopy reveals transitions to short-lived 3p Rydberg states that have a large oscillator strength.