高离化态离子及其光电离过程基本特征的理论研究

在Dirac-Slater相对论理论框架下,研究了HCI（高离化态离子）的基本性质及其光电离过程的基本特征. 通常HCI的电场非常强,其电子波函数沿靠近核的径向空间被压缩,这极大地改变了相应的物质的性质,使HCI的光电离过程与一般的原子（离子）的相比较有很大的不同：原子核的尺寸效应和相对论效应变得更加重要,而多极效应对光电离截面的影响却趋于减弱.     

高离化态离子及其光电离过程基本特征的理论研究

在Dirac-Slater相对论理论框架下,研究了HCI(高离化态离子)的基本性质及其光电离过程的基本特征.通常HCI的电场非常强,其电子波函数沿靠近核的径向空间被压缩,这极大地改变了相应的物质的性质,使HCI的光电离过程与一般的原子(离子)的相比较有很大的不同:原子核的尺寸效应和相对论效应变得更加重要,而多极效应对光电离截面的影响却趋于减弱.     

高离化态金离子的辐射复合及其退激发过程的理论研究

利用基于多组态Dirac-Fock方法的程序包GRASP92和RATIP以及最新发展的RERR06程序,详细计算了高离化态金离子(类镍Au51+、类铜Au50+和类锌Au49+)俘获一个自由电子到nl(n=4—8,l=0—3)壳层的辐射复合谱以及相应的辐射退激发谱.理论计算的辐射复合谱很好地重现了实验谱.研究结果表明:对类镍Au51+、类铜Au50+和类锌Au49+而言,将一个自由电子俘获到n=4壳层的概率最大;在辐射复合过程之后,处在n=4壳层的俘获电子的辐射退激发谱线最强,并且体现了整个辐射退激发谱的主要特征.     

锂原子光电离过程中的弛豫效应

利用基于多组态Dirac-Fock方法的程序包GRASP92和RATIP以及在此基础上最新发展的RERR06程序,计算了锂原子1s²nl(n=2,3; l=s, p) 的内壳层和外壳层的光电离截面. 计算中详细考虑了光电离过程中的弛豫效应. 结果表明：在锂原子内壳层电子的光电离过程中弛豫效应较强,而在外壳层电子的光电离过程中弛豫效应较弱. 另外,相应于不同态的内壳层光电离过程,其弛豫效应的影响也不同,对激发态的影响比对基态的影响大,对高激发态 关键词： 多组态Dirac-Fock方法 光电离截面 弛豫效应     

Ne原子的1s光电离及其Auger衰变过程的理论研究

利用基于多组态Dirac-Fock理论方法的研究原子结构和性质的程序GRASP92和RATIP以及最新发展的研究光电离和辐射复合过程的程序RERR06,研究了光子能量为947.9 eV时Ne原子的1s光电子谱及其相应的Auger衰变过程.所得结果与其他的理论结果和实验结果符合得很好.通过分析光电离伴随态Ne⁺1s^-12p^-1（^1,3Ｐ）3p的Auger衰变过程可知：3p旁观的Auger跃迁是主要的衰变机制,Ne⁺1s^-12p^-1（¹Ｐ）3p的Auger强度整体上大于Ne⁺1s^-12p^-1（³Ｐ）3p的Auger强度.同时,也预言了光电离伴随态Ne⁺1s^-12p^-1（^1,3Ｐ）3p产生的Ne⁺,Ne²⁺和Ne³⁺末电离态离子的相对丰度分别为0.02,0.58和0.41. 关键词： 光电离 Auger衰变 多组态Dirac-Fock方法     

N II离子禁戒跃迁几率的理论计算

用多组态Dirac Fock方法 ,系统考虑了相对论效应、电子关联、延迟效应等重要贡献 ,计算了NII离子 2p3d— 2p2 以及 2p3d— 2p3p (ΔL =± 2 ,ΔS =± 1)禁戒跃迁的几率 .与已有的理论相比 ,目前计算的精度有了明显提高. The forbidden transition probabilities have been calculated for the 2p3d -2p 2 and 2p3d-2p3p(ΔL=±2, ΔS=±1) spectra of N II by using a large-scale multiconfiguration Dirac-Fock (MCDF) method. The most important effects of relativity, correlation, and relaxation are considered in the calculation Comparing with other calculations, a remarkable improvement is achieved.     

N II离子禁戒跃迁几率的理论计算

用多组态Dirac-Fock方法, 系统考虑了相对论效应、电子关联、延迟效应等重要贡献, 计算了N II离子2p3d-2p2以及2p3d-2p3p (ΔL＝±2, ΔS＝±1)禁戒跃迁的几率. 与已有的理论相比, 目前计算的精度有了明显提高.     

初态波函数改变对原子光电离截面库泊极小值的影响

分别计算了原子光电离跃迁过程的Ｈａｔｒｅｅ－Ｆｏｃｋ（ＨＦ）初态波函数、Ｈａｔｒｅｅ－Ｆｏｃｋ－Ｓｌａｔｅｒ（ＨＦＳ）初态波函数和ＨＦＳ末态波函数，并就两种不同初态波函数，对部分元素的不同壳层的光电离跃迁库泊零点能进行了计算，最后对两种计算结果作了比较。     

类氦铷、铌离子光电离截面的细致计算

采用HF加相对论修正的HFR方法,考虑束缚组态间的相互作用,计算了类氦铷与类氦铌离子各能级间跃迁的光电截面,所包括的离子组态为1s nl-1s εl± 1(1≤n≤6、 0≤n≤1),取自由电子能量区间为0 ~10倍的离化能,分析了系统计算误差与计算精度,给出了对末态求和及三次样条插值后的结果。     

碳原子离子光电离截面的相对论多极计算

基于Dirac-slater自洽场方法，本文计算了C元素各价离子从低能到高能的光电离截面，考察了多极效应、相对论效应在不同能区对光电离截面的影响，并研究了光电离截面随光子能量、电离度、不同壳层变化的规律．通过各种理论计算结果的比较，分析了Kramers公式的适用性，计算中为了提高计算精度，我们采用了Grasp2程序包输出的束缚态波函数替换自洽场的波函数。     

高电荷态离子与表面相互作用

论述了高电荷态离子与表面相互作用的过程 ,说明了发射电子、发射光子、负离子、中性粒子、正离子的散射和发射的物理机理以及应用前景 .介绍了在兰州重离子国家实验室ECR源建立高电荷态离子与表面相互作用的原子物理平台的重要意义和将要开展的工作.The interaction between highly charged ions and surface is investigated, the mechanisms for emissions of electrons, photons and scattered neutral particles, negative and positive ions are reviewed. We report a new atomic physics station in ECR and our work plan.     

Guiding of Highly Charged Ions through PC Nanocapillaries

Angular distribution and current dependence of the transmitted ion fraction are investigated for 40keV Xe^7＋ bombarding on polycarbonate （PC） nanocapillaries. By measuring the angular distribution of the transmitted ion fraction, a strong guiding effect is found in PC nanocapillaries. Furthermore, with increase of the incident current, a turning point of the transmitted ion fraction is found, which is explained qualitatively by the discharge capacity of the nanocapillaries.     

Theoretical Studies on Expressions of Condensed-Phase Photoionization Cross Section

A set of general expressions for photoionization cross sections of atoms or molecules embedded in a medium and a dielectric influence function are derived based on Maxwell‘s equations and the Beer-Lambert‘s law in this work.The applications are performed for the photoionization process of solid gold both in the Clausius-Mossotti (virtual cavity) model and the Glauber-Lewenstein (real cavity) model firstly. The results show that the present theoretical expressions of photoionization cross section can be used to describe the photoionization process of atoms in condensed matter properly.     

Theoretical Studies on Photoionization Cross Sections of Solid Gold

Accurate expression for photoabsorption (photoionization) cross sections of high density system proposed recently is used to study the photoionization of solid gold. The results show that the present theoretical photoionization cross sections have good agreement both in structure and in magnitude with the experimental results of gold crystal. The studies also indicate that both the real part ε' and the imaginary part ε" of the complex dielectric constant ε, and the dielectric influence function of a nonideal system have rich structures in low energy side with a range about 50 eV, and suggest that the influence of particle interactions of surrounding particles with the photoionized particle on the photoionization cross sections can be easily investigated using the dielectric influence function. The electron overlap effects are suggested to be implemented in the future studies to improve the accuracy of theoretical photoionization cross sections of a solid system.     

Theoretical Studies on Expressions of Condensed-Phase Photoionization Cross Section

A set of general expressions for photoionization cross sections of atoms or molecules embedded in a medium and a dielectric influence function are derived based on Maxwell＇s equations and the Beer-Lambert＇s law in this work. The applications are performed for the photoionization process of solid gold both in the Clausius-Mossotti （virtual cavity） model and the Glauber-Lewenstein （real cavity） model firstly. The results show that the present theoretical expressions of photoionization cross section can be used to describe the photoionization process of atoms in condensed matter properly.     

Isotope Shifts of Energy Levels in Helium-Like Highly Charged Ions

Optics and Spectroscopy - Isotope shifts of $$n = 1$$ and $$n = 2$$ levels and corresponding transitions in helium-like highly charged ions are calculated with high precision. The total value of...     

聚焦慢速高荷态重离子束微束斑X射线源

利用电子束离子源(EBIS)或者电子束离子陷阱(EBIT)产生的慢速高电荷态重离子束轰击金属靶面,离子束与靶面作用并复合辐射特征X射线;并将高荷态离子束采用离子光学系统会聚为微细束后再与靶面作用,能够辐射出微米甚至亚微米级、纳米级的微束斑X射线.本文介绍这一新型微束斑X射线源的结构、机理及其特性等.