KLL dielectronic recombination process of He-like to O-like xenon ions

In this work, the KLL dielectronic recombination (DR) processes of highly charged He-like to O-like xenon ions are studied systematically by using a DR program, which is based on the multi-configuration Dirac-Fock (MCDF) method. The KLL DR resonant energies and the corresponding resonant strengths are calculated, asizing especially the effect of the Breit interaction on the DR strengths. The theoretical KLL DR spectra are obtained and compared with the latest experimental results obtained in the Shanghai Electron Beam Ion Trap.     

Relativistic Distorted-Wave Collision Strengths of Ni-, Cu- and Zn-like Au Ions

Excitation energies and electron impact excitation strengths from the ground states of Ni-, Cu- and Zn-like Au ions are calculated. The collision strengths are computed by a 213-levels expansion for the Ni-like Au ion, 405- levels expansion for the Cu-like Au ion and 229-levels expansion for the Zn-like Au ion. Configuration interactions are taken into account for all levels included. The target state wavefunctions are calculated by using the Grasp92 code. The continuum orbits are computed in the distorted-wave approximation, in which the direct and exchange potentials among all the electrons are included. Excellent agreement is found when the results are compared with previous calculations and recent measurements.     

等离子体屏蔽效应对类氢离子能级结构和辐射跃迁性质的影响

在Debye-Hückel屏蔽近似下,基于相对论Dirac-Fock方法,发展了包括等离子体屏蔽效应的自洽场计算程序.使用该程序研究了等离子体屏蔽效应对类氢离子能级结构和辐射跃迁性质的影响.结果表明,当原子处于等离子体环境中,所有束缚态能级向连续态移动, 移动量随着屏蔽长度的减小而增大.振子强度随屏蔽长度的变化也表现出了相同的规律.进一步分析了相对论效应和等离子体屏蔽效应的耦合,发现对于中Z元素,相对论效应和等离子体屏蔽效应存在较强的耦合.讨论了等离子体屏蔽效应对原子精细结构能级的影响.计算发现,由于等离子体屏蔽效应,原子的能级次序发生了变化,κ简并被消除. 关键词： 等离子体屏蔽 Debye-Hückel 模型 能级结构 跃迁概率     

类氖离子中的能级交叉及其对辐射光谱的影响

本文利用基于相对论多组态Dirc-Fock理论方法的程序包GRASP92以及新近发展的计算辐射跃迁的程序REOSS99，通过对电子关联效应、驰豫效应的系统考虑，计算了类氖等电子系列 (Z=21-92) 离子2p6, 2p53l, 2s2p63l(l=0,1,2)的能级结构和各能级间E1跃迁的波长以及跃迁几率；基于以上计算，详细研究了由于强组态相互作用引起的具有相同宇称和总角动量的能级间的交叉现象及其强组态相互作用对辐射跃迁几率的影响。     

裸核离子与中性原子碰撞电离过程的理论研究

基于处理裸核离子与中性原子碰撞电离过程的OBKN和ECPSSR理论模型,系统计算了不同裸核离子与中性原子碰撞K壳层电子俘获截面和直接电离截面,并与其它文献已有的理论和实验结果进行了比较.研究结果表明:碰撞能量较低时,电子俘获截面大于直接电离截面,随着碰撞能量的增加,电子俘获截面和直接电离截面均是先增大后减小且直接电离截面减小地非常缓慢,高能时,直接电离截面大于电子俘获截面.当入射炮弹离子速度接近0.67倍靶原子K壳层电子速度时,电子俘获截面达到最大值,而当入射炮弹离子速度接近靶原子K壳层电子速度时,直接电离截面达到最大值.     

Two-electron and one-photon transitions in highly charged nickel-like ions

This paper calculates the transition wavelengths and probabilities of the two-electron and one-photon (TEOP) transition from the $(3{\rm s}^{-1}_{1/2}4{\rm d}_{j})_{J=1,2}$ to $(3{\rm p}^{-1}_{3/2}4{\rm s}_{1/2})_{J=1}$ and the $(3{\rm p}^{-1}_{1/2}4{\rm s}_{1/2})_{J=1}$ to $(3{\rm d}^{-1}_{j}4{\rm d}_{j'})_{J=1,2}$ for highly charged Ni-like ions with atomic number $Z$ in the range $47\leq Z\leq92$. In the calculations, the multi-configuration Dirac--Fock method and corresponding program packages GRASP92 and REOS99 were used, and the relativistic effects, correlation effects and relaxation effects were considered systematically. It is found that the TEOP transitions are very sensitive to the correlation of electrons, and the probabilities will be enhanced sharply in some special $Z$ regions along the isoelectronic sequence. The present TEOP transition wavelengths are compared with the available data from some previous publications, good agreement is obtained.     

Electron Impact Excitations and Linear Polarization for 1s2 1S0-1s2p3,1P1 Lines of Fe24＋ Ions under Screened Coulomb Interactions

Electron impact excitation cross sections from the ground state to the individual magnetic sublevels of 1s2p 3＇1P1 states in high-temperature dense plasmas are calculated for highly charged He-like Fe24＋ ions by using a fully relativistic distorted-wave method. The Debye-Huckel screening model is used to screen the projectile electron from the nucleus and target electrons. The linear polarization degrees for these lines are obtained. It is found that the cross sections at all incident energies decrease with the increase of the screening for these excitations. The influence of screening on linear polarization degrees of the 1P1 line is very small. The linear polarization degrees of aP1 line decrease sharply at low incident energy with the increase of the screening.     

高精度角度加工技术研究

激光陀螺不仅对合光棱镜角度精度有极高的要求,而且对角度和尺寸的一致性有严格的限制。为了加工这种高精度角度光学元件,提出通过手修工装母体复制出成盘加工工装,再复制出光学零件的加工方法,并分析了测角仪的测量精度、面形之间的匹配误差和平行的测量误差所引入的角度加工误差情况,提高了面形加工的平面度,避免了局部不规则现象,控制了温差对面形变化的影响。另外通过降低平行测量的误差以及减小闭合角度之间的叠加误差等具体措施也可以提高光学元件加工效率和角度加工精度。     

Be^+离子和Li原子极化率和超极化率的理论研究

利用相对论模型势方法计算了Be^+离子和Li原子的波函数、能级和振子强度,进一步得到了基态的电偶极极化率和超极化率,并详细地分析了不同中间态对基态超极化率的贡献.对于Be^+离子,电偶极极化率和超极化率与已有的理论结果符合得非常好.对于Li原子,电偶极极化率与已有的理论结果符合得很好,但是不同理论方法计算给出的超极化率差别非常大,最大的差别超过了一个数量级.通过分析不同中间态对Li原子基态超极化率的贡献,解释了不同理论结果之间有较大差异的原因.     

致密气藏储层干化剂在超临界CO2中的溶解性及增溶研究

以离子型碳化物A_XC_Y作为干化主剂注入致密气藏储层中与地层水发生化学反应能够消耗地层水、降低储层含水饱和度,从而提高气体渗流能力。但由于致密气藏储层孔喉较小,固体A_XC_Y颗粒通常难以直接注入其中,因此需要寻找一种有效的干化剂注入方法。通过实验研究发现,超临界二氧化碳(SCCO_2)能够溶解少量无机化合物A_XC_Y,且降压后A_XC_Y析出。故可采用SCCO_2作为输送剂将A_XC_Y溶解并将其有效带入致密储层孔隙中。以此为基础,本文进一步研究了温度和压力对A_XC_Y在SCCO_2中的溶解度的影响;并对多种物质进行测试,优选出了最佳的夹带剂及其用量对A_XC_Y进行增溶。研究结果表明:A_XC_Y可溶解于SCCO_2,在8MPA、40℃下的溶解度为0. 0005mol·mol;且溶解度随压力的升高而增加,但温度对溶解度的影响随压力的变化呈现出非单一的变化规律;此外,以乙醇作为夹带剂具有明显且优于其他物质的增溶效果,其最佳摩尔浓度为10%。