电子与类锂离子碰撞激发截面和速率系数

用自编的扭曲波程序ＡＣＤＷ（９）和拟合程序ＦＩＴ（９），计算了一系列类锂离子的碰撞激发过程．找出了约化碰撞强度Ω_ｒｅｄ是约化电子能量ε_ｒｅｄ的慢变函数，约化速率系数因子γ_ｒｅｄ是约化电子温度Ｔ_ｒｅｄ的慢变函数．对某种离子的一个激发过程，可用１０个参数描述，由这１０个参数可以得到任意电子能量下的碰撞强度和激发截面，以及任意温度下的速率系数 关键词：     

类镍离子的电子碰撞强度和速率系数

用准相对论扭曲波方法系统的计算了Ｐｂ，Ａｕ，Ｂａ，Ｍｏ，Ｇｅ类镍离子组态能级之间的电子碰撞激发强度Ω（ｎｌ－ｎ′ｌ′），３≤ｎ≤７，４≤ｎ′≤７，同时给出了高能极限的碰撞强度和外推到阈值的碰撞强度，用最小二乘样条方法拟合了全能域碰撞强度及热平均速率系数，对于一个激发过程，用１０个参数可以得到碰撞电子在任意能量下的碰撞强度以及任意温度下的速度系数。     

类铜离子的电子碰撞参数及其规律

用准相对论扭曲波方法系统地计算了Ｂａ、Ｎｄ、Ｇｄ、Ｙｂ、Ａｕ、Ｐｂ类铜离子组态能级之间的电子碰撞激发强度Ω（ｎｌ－ｎｌ），３≤ｎ≤７，４≤ｎ≤７，同时给出了高能极限的碰撞强度和外推到阈值的碰撞强度，用最小二乘样条方法拟合了全能域碰撞强度及热平均速率系数。对于一个激发过程，用１０个参数可以得到碰撞电子在任意能量下的碰撞强度以及任意温度下的速率系数。     

Alq+(q=0—12)的光电离截面和Bethe系数

使用Hartree-Fock加相对论修正(HFR)近似计算Al^q+(q=0—12)的光电离截面和Bethe系数,其中Bethe系数将光电离截面与电子碰撞电离截面联系起来,并且决定电子碰撞电离截面的高能行为.分析了光电离截面和Bethe系数随电离度q的变化规律,还与其他数据进行比较,结果表明其数据是可靠的 关键词： 光电离 截面 Bethe系数     

电子与类铍N3+和O4+离子碰撞激发截面的相对论扭曲波计算

采用全相对论扭曲波方法,系统地计算了类铍N³⁺和 O⁴⁺离子从基态到2s2p和2p² 的各激发态以及从亚稳态到2p²各激发态的电子碰撞激发截面,详细地讨论了靶态的关联效应对激发截面的影响.结果表明：对于2s-2p的单电子激发,在低能碰撞时,靶态的电子关联效应起非常重要的作用,且使得激发截面降低;而高能碰撞时,靶态波函数的描述对连续态波函数的影响比较小,对激发截面影响也比较小.对于2s²-2p²的双电子激发,其中基态2s²¹S₀到J=0的2p²³P₀,¹S₀的激发截面较大,其主要原因是末离子态波函数与基组态波函数的混合,但是其他几个激发的激发截面较小. 关键词： 全相对论扭曲波方法 电子碰撞激发 电子关联效应     

Auq+(q=47,55)离子的电子碰撞强度与速率系数

用准相对论扭曲波方法计算了Au^q+（q=47,55）离子的组态重心能级之间的电子碰撞激发强度和速率系数（简称激发参数）．着重分析了高能区光学允许跃迁的碰撞强度的行为，探讨了平面波近似的适用范围．与其他完全相对论数据比较，表明剩余的相对论效应是不大的．阐述了由约化量的5点样条值内插可得任意能量的碰撞强度和任意温度的速率系数．演示了碰撞强度随能量的变化，有效碰撞强度和速率系数随温度的变化．结果表明在类镍金两侧各延伸的4种不同荷电离子，其单电子激发参数变化小于10%，这对于使用平均原子模型     

激发态铯原子间的碰撞能量转移

用激光抽运基态Cs₂分子,通过预离解或碰撞转移,由一部分的激发态Cs₂产生Cs原子6P,5D激发态。测量了Cs(5D)+Cs(6P)→Cs(7D_J)+Cs(6S)碰撞激发能量转移截面σ_(7DJ),以及Cs(7D_J)+Cs(6S)→除Cs(7D)外的态的截面σ_tr。结果是,对于J=5/2,3/2,σ_(7DJ)(以 关键词：     

用负温度高能离子束的相对论多普勒效应实现从红外到X射线连续调谐激光器

利用负温度高能离子束的相对论多普勒效应,可能实现从红外到X射线连续调谐激光器。调谐范围△ν_T=2ν₀βγ。离子束从零到c调速时,激光频率为0—∞。本文给出了激光参数的相对论变换式,计算了负温度相对论离子束激光器的增益、阈值和输出特性,提出了用激光束对相对论离子束进行共振激发的方法,并讨论了He⁺离子束及Ar⁺离子束激光器的设计参数。 关键词：     

U^91＋离子碰撞强度和速率系数的相对论理论计算

介绍了用相对论多通道理论结合量子亏损理论计算电子碰撞激发过程的方法。用此方法计算了U^91 离子电子碰撞激发的碰撞强度和有效碰撞强度及速率系数。与R矩阵方法的计算结果比较表明：在激发能量阈值附近还有一组共振结构;目前的方法对共振结构的描述更精细完整。根据碰撞强度,通过对电子速度的麦克斯韦分布积分得到了有效碰撞强度与温度的关系。可以看出,碰撞强度在能量阈值附近的共振峰使低温1s-2s跃迁有效碰撞强度增大近20％。     

Li2Mo2O6多晶材料的结构与电性能的研究

本文用固相反应烧结制备出Li₂Mo₂O₆多晶材料。经X射线分析、红外光谱和电子顺磁共振谱(EPR)的研究,确定了它的结构是Li₂Mo₂O₄和MoO₂两个晶相组成的烧结体。钼离子以四价状态存在于MoO₂晶相结构中。采用交流阻抗谱分析了晶界与温度变化的相关性。测得了样品的ln(σ_总T)-1/T 曲线是由两段直线和一段曲线所组成;总电导率化能σ_27℃=1.36×10^-3(Ω·cm)^-1,σ_115℃=1.49×10^-3(Ω·cm)^-1,σ_300℃=9.71×10^-3(Ω·cm)^-1,σ_370℃=2.42×10^-3(Ω·cm)^-1;电导活化能E₁=0.043eV,E₂=0.235eV,E_平均=0.76eV。采用维格纳极化电池法测得电子电导率σ_e,σ_e27℃=2.240×10^-5(Ω·cm)^-1,σ_e300℃=4.476×10^-3(Ω·cm)^-1。实验证明,室温下材料为固体电解质,300℃附近为良好的离子与电子混合导体。 关键词：     

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     

DTO分子反应碰撞的非对称性

基于DTO分子（X¹A₁）的氢同位素效应,得到修正的Born-Oppenheimer（B-O）理论下多体展式分析势能函数.用准经典的Monte-Carlo轨迹法研究了O+DT（0,0）的分子反应动力学过程.结果表明：在碰撞能量较低时（<209.2?kJ·mol^-1）,O+DT（0,0）可以生成长寿命络合物DTO（X¹A₁）,并且该络合反应是无阈能的,这一结论与多体项展式理论计算的DTO分子势能曲线结果一致.碰撞能大于209·2?kJ·mol^-1时,逐渐出现置换产物TO和DO,随碰撞能进一步增大,分子将被完全碰散成D,T,O原子.反应O+DT（0,0）→OD+T和O+DT（0,0）→OT+D是有阈能的反应,置换产物TO和DO轨线存在非对称性. 关键词： DTO 势能函数 分子反应碰撞 轨线非对称性     

Electron impact excitation of the resonance transitions of highly ionized atoms of the Be-, Mg-, and Zn-isoelectronic sequences

Electron impact excitation collision strengths for the ns²¹S - nsnp¹P resonance transitions of highly ionized Be, Mg, and Zn-like ions have been computed in the distorted wave approximation, including the effects of exchange and target state correlation. Good agreement is observed between these data and collision strengths computed in the Coulomb-Born and Born approximations at high incident energies. Analytic fits to the distorted wave data are presented.     

Stimulated Raman scattering of an extraordinary mode in a solid state plasma

This paper presents an investigation of stimulated Raman scattering of an extraordinary mode in a solid state plasma, n In Sb. As the pump wave (w₀, k₀) propagates in the semiconductor the electrons acquire an oscillatory drift velocity and the magnetic field of the pump interacts with a low frequency perturbation (w_l, k_l) to give rise to high frequency side bands (w_l ± w₀, k_l ± k₀). The side band (w_l − w₀, k_l − k₀) interacts with the pump to produce a low frequency ponderomotive force responsible for driving the original density perturbation. The expressions for the growth rate and threshold for the instability have been obtained. For typical plasma parameters of n In Sb and laser radiation of frequency 1.778 × 10¹⁴s⁻¹, the growth rate turns out to be ~ 10¹¹s⁻¹ for the scattering angle θ = 0°. The growth rate is found to reduce with increasing values of scattering angle. A magnetic field enhances the growth rate and tends to reduce the threshold for the instability. The present investigation may be used to obtain useful information about the nature of elementary excitations in solid state plasmas, and the estimate of the growth rate may help in diagnostics and in the characterization of semiconductors.     

Dynamical coupling in the differential equations approach to atom-diatom exchange reactions

The atomic exchange reaction A + BC → AB + C is investigated quantum mechanically employing a coupled differential equations approach. The relative motion in reactant and product channels is described in the common coordinate R ₃ (the AC nuclear separation) and is developed in three-dimensional space. The total wave functions of the system are expressed as a superposition of valence bond electronic states of the initial (A, BC) and final (AB, C) configurations, with the coefficients describing the relative and internal (vibrational, rotational) nuclear motions. Choosing convenient trial functions with the appropriate boundary conditions and using the Kohn variational principle, a set of differential (rather than the usual integro-differential) equations is obtained for the relative motion wave functions in R ₃. The potential matrix elements turn out to be dynamical in that they depend on the initial k ₁ and final k ₂ wave vectors. Two-state coupled channel calculations of the differential and integral cross sections for the isotopic species D + H₂, H + H₂ and D + D₂ are presented for collision energies up to 0·8 eV.     

Instability of electromagnetic waves in transversely magnetised semiconductor-plasmas

Using the hydrodynamic model of plasmas the general dispersion relation is derived in the collisiondominated regime when a d.c. magnetic field is applied (Y-axis) transversly to the propagation vector k (Z-axis), and the d.c. electric field is inclined to the Z-axis in the X-Z plane. The dispersion relation is solved for intrinsic and extrinsic semiconductors to explore the possibility of wave instability. The threshold conditions of wave oscillations are obtained. In n-InSb the frequency of the oscillation attains a maximum value when the electron cyclotron frequency is equal to the electron collision frequency. In intrinsic InSb instability is possible only in the long wavelength region for E₀ ? 10 kVm^?1 when B₀> 0.2 T, while for lower values of B₀, E₀ should be greater 20kVm^?1. The energy dependent collision frequency has a significant effect on the threshold frequency of oscillation.     

X-ray emission via Kα resonance complexes in gold ions

The excitation energies from ground state for 63 fine structure levels of the terms belonging to 1 s², 1snl, 2lnl′ (n = 2,3), 3l3l′ (l ≠ ≠ l′) configurations of Au⁷⁷⁺, as well as oscillator strengths for electric-dipole-allowed and intercombination transitions among the fine-structure levels were theoretically evaluated. The important relativistic effects in intermediate coupling are incorporated by means of the Breit–Pauli Hamiltonian. Extensive comparisons are performed with several approximations and previous data sets in order to size up contributing effects and to estimate accuracy ratings. The atomic excitation is obtained by electron impact in close coupling approach. For optically allowed transitions, the electron-impact collision strengths at collision energy up to 80 keV are reported. The results are relevant to the laboratory and astrophysical plasmas.     

Collision strengths for the N = 2 excitation of hydrogenic ions

An empirical formula is given for the estimation of the collision strengths for electron impact excitation of the 2s and 2p states of hydrogenic systems based on close coupling calculations. The coefficients in this formula are given as functions of the nuclear charge, Z, thereby making a possible estimation of the collision strength for any system between H and Fe²⁵⁺.     

Molecular constants of LiCl(X~1Σ~+) and elastic collisions of two ground-state Cl and Li atoms at low and ultralow temperatures

Interaction potentials for LiCl(X 1 Σ +) are constructed by the highly accurate valence internally contracted mul-tireference configuration interaction in combination with a number of large correlation-consistent basis sets,which are used to determine the spectroscopic parameters (D 0,D e,R e,ω e,ω e χ e,B e and α e).The potentials obtained at the basis sets,i.e.,aug-cc-pV5Z-JKFI for Cl and cc-pV5Z for Li,are selected to study the elastic collision properties of Li and Cl atoms at the impact energies from 1.0×10 12 to 1.0×10 4 a.u.The derived total elastic cross sections are very large and almost constant at ultralow temperatures,and their shapes are mainly dominated by the s-partial wave at very low impact energies.Only one shape resonance can be found in the total elastic cross sections over the present collision energy regime,which is rather strong and obviously broadened by the overlap contributions of the abundant resonances coming from various partial waves.Abundant resonances exist for the elastic partial-wave cross sections until l=22 partial waves.The vibrational manifolds of the LiCl(X 1 Σ +) molecule,which are predicted at the present level of theory and the basis sets cc-pV5Z for Li and the aug-cc-pV5Z-JKFI for Cl,should achieve much high accuracy due to the employment of the large correlation-consistent basis sets.     

T+OD体系的同位素交换反应动力学

基于DTO(Χ¹ A₁)分子的多体展式分析势能函数,用准经典的Monte Carlo轨迹法研究了T+OD(0,0)体系的分子反应动力学过程. 结果表明,在碰撞能较低(小于121.34 kJ ·mol^-1)时,可以生成长寿命DTO(Χ¹ A₁)络合物,并且该络合反应是有阈能反应,这与用多体项展式理论计算的DTO分子势能曲线结果一致. 随碰撞能增加,逐渐出现置换产物DT和OT,最终分子被完全碰散成D,T和O原子,而且反应T+OD(0,0)→OT+D,T+OD(0,0)→DT+O和T+OD(0,0)→D+T+O也是有阈能反应. 由于D和T原子的同位素效应,T+OD(0,0)与D+OT(0,0)体系的碰撞反应特征存在非一致性. 关键词： DTO 分子反应动力学 轨线 反应截面