电离度与类HY了子电离能关系的研究

研究了类Ｈ离子电离能与电离度△Ｚ（离子电荷数）之间的关系，给出了类Ｈ离子各电离态电离能的计算公式，并对所有类Ｈ离子的电离能进行了计算。与实验结果或对论多组态Ｄｉｒａｃ－Ｆｏｃｋ方法的结果比较，得到了较满意的结果。     

“水窗”波段类Li离子各电离态的电离能

用相对论多组成Ｄｉｒａｃ－Ｆｏｃｋ方法计算了“水窗”波段类Ｌｉ离子各电离态的电离能，这些能量对于优化复合泵浦软Ｘ射线激光机制具有重要意义。     

用屏蔽法计算较轻元素原子的高次电离能

考虑到离子的相对论效应,依据屏蔽方法,给出了原子第2、1壳层电子电离能的一种表达式.依据较轻元素原子低次(小于13)电离能实验数据,总结出原子(离子)电离第2、1壳层不同电子态电子时,相应的屏蔽系数与电子态及原子序数的函数关系,根据该函数关系,可求出相应原子的高次电离电子的屏蔽系数.计算了原子序数13至23的元素高电荷态离子基态电离能,计算结果与文献可提供的实验数据相符合.     

Al^（10＋）的电子碰撞激发和电离

用扭曲波方法计算了Ａｌ￣（１０＋）离子基态和第一激发态的１ｓ、２ｓ和２ｐ电子的激发和电离截面。激发截面与文献［３］的结果符合很好。同时，２ｓ电离截面与文献［４］的结果也是一致的。在电离阈值处实现了激发截面（乘以“态密度”）与电离能量微分截面的光滑联接。     

HFC-152a的同步辐射真空紫外光电离和光解离研究

利用同步辐射真空紫外光，研究了HFC-152a(CH₃CHF₂)的光电离和光解离过程，通过测量各离子的光电离效率曲线，得到了该分子的电离能(11.94±0.04eV)和所有碎片离子的出现势，运用GAUSSIAN-03程序计算了母体和碎片及相应离子的结构、电子态和能量. 结合理论计算的结果，分析了母体离子可能的光电离解离通道及相关通道的解离能. 关键词： 同步辐射 光电离 出现势 HFC-152a     

类Be离子电子碰撞电离的速率系数计算

本文用Ｓａｍｐｓｏｍ等的“Ｚ－标度类氢模型和库仑玻恩交换近似”方法，修改了Ｓａｍｐｓｏｎ理论中关于屏蔽常数的定义，选用电子机轨道平均半径标准，使用多组态Ｈａｒｔｒｅｅ－Ｆｏｃｋ（ＭＣＨＦ）及多组态Ｄｉｒａｃ－Ｋｏｃｋ（ＭＣＤＦ）方法计算屏蔽常数，并给出了类Ｂｅ离子Ｃ＾２＾＋，Ｎ＾３＾＋，Ｏ＾４＾＋，Ｎｅ＾６＾＋及Ｆｅ＾２＾２＾＋的电离速率系统。从计算结果，可以看到高荷电靶离子的相对论效应。     

Auq+(q=53-47)激光等离子体的辐射复合速率系数

辐射复合过程在超组态碰撞辐射（SCROLL）模型中真实模拟非局域热动力学平衡（non-LTE）高Z材料Au激光等离子体M带谱5f-3d跃迁中各种复杂离子的电离态特性是一个主要过程。基于准相对论多组态Hartree-Fock理论和扭曲波近似,采用组态平均的方法,从头计算了金M带类铁金离子-类锗金离子的辐射复合速率系数,计算过程中包含了大量的单激发和双激发态,结果表明高Z元素由于自电离能级的广泛分布和复杂的级联效应,致使高Z元素的辐射复合系数不同于低Z元素的,其计算结果可用来模拟Au的激光等离子体M带5f-3d跃迁的平均电离度和电荷态分布及能级布居数。     

Auq+(q=53-47)激光等离子体的辐射复合速率系数

辐射复合过程在超组态碰撞辐射(SCROLL)模型中真实模拟非局域热动力学平衡(non-LTE)高Z材料Au激光等离子体M带谱5f-3d跃迁中各种复杂离子的电离态特性是一个主要过程.基于准相对论多组态Hartree-Fock理论和扭曲波近似,采用组态平均的方法,从头计算了金M带类铁金离子-类锗金离子的辐射复合速率系数,计算过程中包含了大量的单激发和双激发态,结果表明高Z元素由于自电离能级的广泛分布和复杂的级联效应,致使高Z元素的辐射复合系数不同于低Z元素的,其计算结果可用来模拟Au的激光等离子体M带5f-3d跃迁的平均电离度和电荷态分布及能级布居数.     

B（OH）3分子的同步辐射光电离研究

报道了利用真空紫外同步辐射光电离法研究Ｂ（ＯＨ）３分子的结果，从所测得的光电离质谱和各种光电离效率曲线，获得了Ｂ（ＯＨ）３的电离势及其碎片离子的出现势，由此导出了分子及其离子中的键离解能。此外，对Ｂ（ＯＨ）３分子在同步辐射作用下的离解电离通道也做了初步的分析。     

超短脉冲强激光场中电子剩余能计算

为了控制光场感应电离等离子体的温度以使得基于光场感应电离机制的X射线激光辐射获得更高的增益值,利用准静态隧道电离模型,定量计算了电子剩余能量与激光偏振参量、波长(频率)、激光强度以及电离介质电离能的变化关系。计算结果表明线偏振短波长激光以及高电离能介质产牛的等离子体中电子剩余能比较低,因此适合用作复合机制X射线激光;对于低价离子存偏振度α介于0～1之间的某一处最高,因此,可以通过调整偏振度α,获得某一椭圆偏振光,会更有利于基于光场感应电离电子碰撞机制X射线激光增益的提高。     

Ionization and recombination rates of dense carbon plasmas

Collisional rate coefficients of excited, hydrogen-like carbon ions are calculated for the dense, non-degenerate plasma state starting from a generalized kinetic equation. Many-body effects like screening, lowering of ionization energies, and quasiparticle energies are taken into account. The resulting density dependence of the impact ionization, recombination, excitation, and deexcitation coefficients is discussed.     

Ionization of Hydrogen and Helium Atoms in Collisions with Relativistic Structural Heavy Ions

Based on the eikonal approximation, cross sections for single and double ionization of hydrogen and helium atoms in collisions with structural multiply charged heavy ions moving with relativistic velocities are calculated. In the present paper, the structural ions are taken to mean the ions with partially filled electronic shells. It is demonstrated that a consideration of the ion charge extension may noticeably change the corresponding cross sections compared to the cross sections for ionization by point ions having the same charges and energies.     

Field ionization within the forbidden zone

Mass spectra of helium and neon obtained by field ionization in the presence of hydrogen or another low ionization potential gas contain lines indicating noble gas ions with energies exceeding those of the ordinary field ions by 16 or 13 eV, respectively. These ions originate from the apex-adsorbed state within the forbidden zone following excitation by impinging electrons from free-space ionization of the auxiliary gas.     

L x‐ray transitions in F‐like to Na‐like xenon ions determined at a room temperature electron beam ion trap

Fluorine‐like to sodium‐like xenon ions were investigated by wavelength‐dispersive x‐ray spectrometry at the Dresden Electron Beam Ion Trap (EBIT) working at room temperature. In addition to the precise measurement of the L x‐ray transition energies following ionization, excitation and recombination processes in the highly charged xenon ions, the spectra were analyzed for different gas pressures in the trap. Multiconfiguration Dirac‐Fock calculations are introduced that were applied to the energies, transition probabilities and excitation cross‐sections. The production of neon‐like xenon ions was demonstrated even at very high gas pressures. Copyright © 2005 John Wiley & Sons, Ltd.     

质子与He+,Li++高能碰撞过程中电子俘获截面的理论计算

用OBK近似和CDW近似计算了H⁺+He⁺和H⁺+Li⁺⁺碰撞过程中电子俘获到激发态的分截面与俘获到基态分截面的比值，结果发现用OBK近似给出的比值和用CDW方法所给出的相应比值在高能区符合得很好．由此提出了一种用于计算高能H⁺与任一类氢离子碰撞的电子俘获总截面及任一激发态分截面的方法 关键词：     

Electron-impact ionization and dissociative ionization of sulfur in the gas phase

We describe the methods and the results of investigation of the yield of positive ions formed as a result of electron-impact ionization of sulfur. The ionization energy for the basic molecule and the energies corresponding to the emergence of fragment ions are obtained from the ionization efficiency curves. The dynamics of formation of molecular sulfur ions in the temperature range 320–700 K is investigated. The energy dependences of efficiency S _n of the ion formation for n = 1–6 are analyzed, and their appearance energies are determined. The total cross section of sulfur ionization by a monochromatic electron beam is also investigated. Using the linear approximation method, we marked out features on the ionization function curve, which correspond to the ionization and excitation energies for multiply charged ions. The total cross section of the formation of negative sulfur ions is measured in the energy range 0–9 eV.     

电子碰撞电离离子三重微分截面的计算

解决了包含四个合流超几何函数的数值积分问题,从而给出了计算电子碰撞电离离子三重微分截面的通用方法,适合于中、高入射能量下的各种几何条件。计算了对称和不对称几何条件下电子碰撞电离He⁺离子的三重微分截面,并与其它理论结果作了比较。     

Interference effect in electron emission in heavy ion collisions with h2 detected by comparison with the measured electron spectrum from atomic hydrogen

Direct evidence of the interference effect in the electron emission spectra from ionization of molecular hydrogen in collisions with bare C and F ions at relatively low collision energies is presented. Oscillations due to the interference are deduced by comparing the measured double differential cross sections of the electrons emitted from molecular hydrogen to those emitted from atomic hydrogen, rather than using the calculated cross sections for H as in a previous report. We believe these experimental data provide stronger support for the evidence of the interference effect. We show that it is not only a feature of very high energy collisions, but also a feature to be observed in relatively lower energy collisions.     

New model for ion neutralization at surfaces

We investigate the neutralization of low energy He⁺ ions in close collisions with metal surface atoms. In order to describe the neutralization process as completely as possible, we consider Auger neutralization (AN), resonant neutralization (RN) and resonant ionization (RI). Our calculation agrees well with experimental data and shows that in some metals (like Pd) AN is the dominant process, whereas in others (like Al) RN and RI contribute significantly for energies above the threshold for reionization.     

相邻类氢离子电离能关系的研究

根据类氢离子电离能的实验值和相邻元素电离能的相关约束方程,定量地建立了各元素类氢离子电离能与核电荷数的较为精确的递推关系.其推算结果与实验值的相对误差小于0.001%,与相对论自洽场方法计算的结果相比,其相对误差也小于0.001%.