Xe8+离子双电子复合速率系数的理论研究

利用基于全相对论组态相互作用理论的FAC程序包, 详细研究了温度在0.1~1650 eV范围内Xe8+离子的双电子复合(DR)过程。 通过比较4s, 4p和4d壳层电子激发的双电子复合速率系数, 发现温度在10 eV以上时, 内壳层4p电子激发的双电子复合速率数对总双电子复合速率系数有很重要的贡献, 而4s电子激发对总双电子复合速率数贡献小于7.5%。 给出了△n=0, 1和2 三类芯激发对总双电子复合速率系数的贡献以及自由电子俘获到不同主量子数的双电子复合速率系数, 发现△n=2的芯激发和n′＞15的DR速率系数对总DR速率系数的贡献也很重要。 进一步给出了△n=0, 1和2 三类芯激发和总DR速率系数的拟合参数, 拟合结果和计算值符合, 偏差小于1%。 通过对双电子复合、 辐射复合以及三体复合速率系数的比较得知, 在温度高于1 eV时, DR过程是Xe8+离子的主要复合过程。Based on the fully relativistic configuration interaction method, theoretical calculations are carried out for the dielectronic recombination (DR) rate coefficients of Xe8+ ions in the temperature region from 0.1 to 1 650 eV. The comparison of the DR rate coefficients from 4s, 4p and 4d subshell excitations shows that 4d subshell excitation dominates in the whole temperature region. The contribution from 4p subshell excitation is very important at temperature above 10 eV and the contributions from 4s subshell excitation is lower than 7.5% in the whole temperature region. Similarly, the comparison of the DR rate coefficients through △n=0, 1 and 2 core excitation shows that the contribution from △n=2 core excitation can not be neglected, the contributions from n′＞15 can also not be neglected. The DR rate coefficients of △n=0, 1 and 2 core excitation and the total DR rate coefficients are fitted with some parameters, which are in good agreement with theoretical calculations values (within 1% difference). The total DR rate coefficients are greater than radiative recombination (RR) and three body recombination (TBR) rate coefficients at temperature above 1 eV. Therefore, the DR process can strongly influence the ionization balance of laser produced xenon plasmas.     

Re30+离子双电子复合速率系数的理论研究

复杂结构离子的双电子复合速率系数在极紫外光刻光源、核聚变等应用研究的等离子体光谱模拟和诊断中具有重要的应用价值。利用全相对论组态相互作用方法,详细计算了基组态为4p64d9的Re30+离子经双激发态（4p64d9）-1nln'l'（n=4~6,n'=4~23）的双电子复合（DR）过程。研究分析了激发、辐射通道,组态相互作用,级联退激对DR速率系数的影响。其中内壳层4p电子激发的DR速率系数是总DR速率系数的28.2%~44.9%,所以内壳层4p电子激发的贡献不可以忽略。级联退激对DR速率系数的最大贡献为12.9%,也必须要予以考虑。通过对双电子复合、辐射复合、以及三体复合速率系数的比较,辐射复合速率系数的最大值为DR速率系数的22.6%,三体复合速率系数的最大值仅为DR速率系数的0.3%。因此,DR速率系数远远大于辐射复合和三体复合速率系数。该结果表明DR过程对于等离子体离化态分布、能级布居以及光谱模拟都极为重要。为了方便应用,对基态和第一激发态的总DR速率系数进行了参数拟合。该研究结果将为Re激光等离子体的光谱模拟及复杂结构离子DR过程的进一步研究提供参考。Dielectronic recombination (DR) rate coefficients of complex ions are very important in some application research, such as extreme ultraviolet lithography and nuclear fusion. Based on the fully relativistic configuration interaction method, theoretical calculations are carried out to research the DR processes, in which Re30+ ions in the ground state 4p64d9 to (4p64d9)-1nln'l'(n=4~6, n'=4~23). Influence of excitation and radiation channels, configuration interaction, the effect of decays to autoionizing levels possibly followed by radiative cascades (DAC) are analyzed. The contributions through 4p subshell excitations to the total rate coefficient are 28.2%~44.9% in the whole temperature region. Hence the contributions from inner-shell electron excitation are very important. The contributions from the DAC transitions increase smoothly with the increasing temperature and are about 12.9% at 50 000 eV. The contributions of DAC can not be neglected. By means of compared total DR rate coefficients to radiative recombination rate coefficients and three-body recombination rate coefficients, it shows that the maximum value of the radiation recombination rate coefficient is 22.6% of the DR rate coefficient and the maximum value of the three-body recombination rate coefficient is only 0.3% of the DR rate coefficient. The total DR rate coefficient is greater than either the radiative recombination or three-body recombination coefficients in the whole temperature range. The corresponding DR process is very important for plasma ionization distribution, population level and spectrum simulation. In addition to facilitate the application, the total DR rate coefficients for the ground state and the first excited state are fitted to an empirical formula. These results will provide the reference for the further analyses of rhenium laser plasma spectrum simulation and the complex structures ions DR process.     

Dielectronic Recombination of Ni-Like Gold Ion Through the Cu-Like 3d^94ln＇l＇ （n＇= 4, 5） Configurations

Ab initio calculations of dielectronic recombination (DR) rate coefficients from the ground state of Ni-like A u ion through the Cu-like 3d^94ln‘l‘ (n‘= 4, 5) configurations have been performed by using a relativistic atomic code FAC with configuration interaction. The DR rate coefficients through the 3d^94l5f5/2 and 3d^94l5f7/2 configurations are evaluated separately. The contributions from resonant and nonresonant radiative stabilizing transitions to the total rate coefficients are distinguished and discussed. The decays to autoionizing levels followed by radiative cascades are included in the calculation.     

钨离子双电子复合过程的理论研究

利用全相对论组态相互作用理论方法, 研究了W28+离子由基态俘获一个电子形成双激发态(3d104s24p64d10 )-1 nln'l'(n = 4~6, n' = 4~15)的双电子复合(DR)过程. 比较分析了3s、3p、3d、4s、4p和4d电子激发对DR速率系数的贡献, 分析了3d、4s、4p和4d电子激发的DR速率系数随轨道量子数l' 的变化. 考虑和已有的计算完全相同的初态, 中间双激发态以及辐射和俄歇末态的情况下, 得到了和已有的计算符合很好的结果. 在综合了分析得到的对W28+离子DR过程有明显贡献的各种因素后,进一步得到了总DR速率系数. 其中, 考虑DAC效应对总DR速率系数有不可忽略的影响. 对DR速率系数进行了参数拟合, 拟合值与计算值的偏差小于1％.     

Enhancement of electron–ion recombination rates at low energy range in the heavy ion storage ring CSRm

Recombination of Ar¹⁴⁺, Ar¹⁵⁺, Ca¹⁶⁺, and Ni¹⁹⁺ ions with electrons has been investigated at low energy range based on the merged-beam method at the main cooler storage ring CSRm in the Institute of Modern Physics, Lanzhou,China. For each ion, the absolute recombination rate coefficients have been measured with electron–ion collision energies from 0 meV to 1000 meV which include the radiative recombination(RR) and also dielectronic recombination(DR)processes. In order to interpret the measured results, RR cross sections were obtained from a modified version of the semiclassical Bethe and Salpeter formula for hydrogenic ions. DR cross sections were calculated by a relativistic configuration interaction method using the flexible atomic code(FAC) and AUTOSTRUCTURE code in this energy range. The calculated RR + DR rate coefficients show a good agreement with the measured value at the collision energy above 100 meV.However, large discrepancies have been found at low energy range especially below 10 meV, and the experimental results show a strong enhancement relative to the theoretical RR rate coefficients. For the electron–ion collision energy below 1 meV, it was found that the experimentally observed recombination rates are higher than the theoretically predicted and fitted rates by a factor of 1.5 to 3.9. The strong dependence of RR rate coefficient enhancement on the charge state of the ions has been found with the scaling rule of q^3.0, reproducing the low-energy recombination enhancement effects found in other previous experiments.     

钨离子双电子复合过程的理论研究

摘要: 利用全相对论组态相互作用理论方法, 研究了W28+离子由基态俘获一个电子形成双激发态(3d104s24p64d10 )-1 nln''l''(n = 4~6, n'' = 4~15)的双电子复合(DR)过程. 比较分析了3s、3p、3d、4s、4p和4d电子激发对DR速率系数的贡献, 分析了3d、4s、4p和4d电子激发的DR速率系数随轨道量子数l'' 的变化. 考虑和已有的计算完全相同的初态, 中间双激发态以及辐射和俄歇末态的情况下, 得到了和已有的计算符合很好的结果. 在综合了分析得到的对W28+离子DR过程有明显贡献的各种因素后,进一步得到了总DR速率系数. 其中, 考虑DAC效应对总DR速率系数有不可忽略的影响. 对DR速率系数进行了参数拟合, 拟合值与计算值的偏差小于1％.     

The dielectronic recombination process in laser-produced Au plasmas

The calculations of the rate coefficients for dielectronic recombination (DR) along the NiI isoelectronic sequence in the ground state Au^{51+} through Cu-like 3d^9nln′f (n,n′=4,5,6) inner-shell excited configurations are performed using the spin-orbit-split array (SOSA) model. Resonant and nonresonant radiative stabilizing transitions and decays to autoionizing levels followed by radiative cascades are included. Collisional transitions following electron capture are neglected. The trend of the DR rate coefficients and the ratio of dielectronic satellite lines intensities with the change of the electron temperature are discussed.     

Dielectronic recombination rate coefficient for Cu-like Au^50＋ ion

The rate coefficients α^{DR} of dielectronic recombination (DR) for Cu-like Au^{50+} ion collided with the incident free electron are calculated based on the quasi-relativistic multi-configuration Hartree－Fock theory. The results clearly show that the α^{DR} of all recombination channels exhibits resonance characters with electron temperature. At lower temperatures, the recombination for electrons caused by 4s excitation is dominant through outer electron radiative transitions among the intermediate doubly excited autoionizing levels, in which the most components come from 3d^{10}5pns states, whereas with increasing electron temperature, DR caused by 3d excitation turns out to be dominant, and the contribution from the 3d^94s4fnf state to the total rate coefficient of electron 3d is the largest with α^{DR}=1.15×10^{- 11} cm^3·s^{-1} at an electron temperature of T_e=0.35 keV. Under this condition, there exists a strong competition between the two types of recombination channels.     

W~(28+)离子双电子复合速率系数的理论研究

利用全相对论组态相互作用理论方法,研究了W~(28+)离子由基态俘获一个电子形成双激发态(3d~(10)4s~24p~64d~(10))~(-1)nln'l'(n=4~6,n'=4~15)的双电子复合(DR)过程.比较分析了3s、3p、3d、4s、4p和4d电子激发对DR速率系数的贡献,分析了3d、4s、4p和4d电子激发的DR速率系数随轨道量子数l'的变化.考虑和已有的计算完全相同的初态,中间双激发态以及辐射和俄歇末态的情况下,得到了和已有的计算符合很好的结果 .在综合了分析得到的对W~(28+)离子DR过程有明显贡献的各种因素后,进一步得到了总DR速率系数.其中,考虑DAC效应对总DR速率系数有不可忽略的影响.对DR速率系数进行了参数拟合,拟合值与计算值的偏差小于1%.     

Dielectronic Recombination of Sn^10＋ Ions and Related Satellite Spectra

Based on the multi-configuration Dirac-Fock method, theoretical calculations are carried out for the dielectronic recombination （DR） rate coefficients and the collision excitation rate coefficients of Sn^10＋ ions. It is found that the total DR rate coefficient has its maximum value between 10eV and 100eV and is greater than either the radiative recombination or three-body recombination rate coefficients （the number of free electrons per unit is 10^21 cm^3） for the ease of Te 〉 1 eV. Therefore, DR can strongly influence the ionization balance of laser produced multi-charged tin ions. The related dieleetronie satellite cannot be ignored at low temperature Te 〈 5 eV.     

类铷W37+离子双电子复合速率系数的理论研究

 利用全相对论组态相互作用理论方法,研究了类铷W³⁷⁺离子从基组态3s²3p⁶3d¹⁰4s²4p⁶4d经过双激发态(3s²3p⁶3d¹⁰4s²4p⁶4d)^-1nln′l′(n,n′=4,5)的双电子复合过程,得到了该离子在温度为1~5×10⁴ eV范围内的总双电子复合速率系数。分析比较了不同电子激发的双电子复合速率系数,结果表明:4p电子激发的双电子复合速率系数在低温时给出了主要贡献,而3d的贡献在高温时突出。由于强组态相互作用,两电子一光子跃迁对双电子复合速率系数的贡献不可忽略,其中辐射跃迁4p⁵4d5d5f-4p⁶4f5d的贡献是双激发态4p⁵4d5d5f总的双电子复合速率系数的5%。对双电子复合、辐射复合以及三体复合速率系数的比较表明,在所研究的温度范围内双电子复合速率系数最大。     

Dielectronic recombination of Co-like tantalum

Ab initio calculation of the total dielectronic recombination (DR) rate coefficient from the ground state of Co-like tantalum is performed using the relativistic distorted-wave approximation with configuration interaction. The contributions to the total DR rate coefficients are explicitly calculated from the complexes of Ni-like tantalum: 3s²3p⁶3d_3/2³ 3d_5/2⁶ n'l', 3s²3p⁵3d¹⁰n'l', 3s3p⁶3d¹⁰n'l', 3s²3p⁶3d⁸4ln'l', 3s²3p⁵3d⁹4ln'l' and 3s3p⁶3d⁹4ln'l' with n' ≤ 25, and 3s²3p⁶3d⁸5ln'l' with n' ≤ 9. The l' and n' dependences of partial DR rate coefficients are investigated. The contributions from higher n'complexes are evaluated by a level-by-level extrapolation method. The total DR rate coefficients mainly come from the complex series 3s²3p⁶3d⁸4ln'l', 3s²3p⁵3d⁹4ln'l' and are fitted to an empirical formula with high accuracy. Comparison of the present results with those of other works shows that the previously published data underestimate significantly the DR rates of Co-like tantalum.     

Au~(34+)离子双电子复合过程的理论研究

复杂结构离子的双电子复合(DR)速率系数在核聚变、极紫外光刻光源等应用研究的等离子体谱模拟中具有重要的价值.利用基于全相对论组态相互作用理论的FAC程序包,详细计算了Au~(34+)离子的双电子复合速率系数.研究分析了激发、辐射通道,组态相互作用,级联退激对DR速率系数的影响.其中,级联退激对DR速率系数的贡献必须予以考虑.对双电子复合、辐射复合以及三体复合速率系数做了比较,在温度大于1 eV范围,双电子复合都大于辐射复合以及三体复合速率系数,相应的DR过程对于等离子体离化态分布和能级布居以及光谱模拟都极为重要.对基态和第一激发态的DR速率系数进行了参数拟合,拟合值与计算值的偏差小于1.73%.研究结果将为复杂结构离子双电子复合过程的进一步研究提供参考.     

X-ray spectra simulation of Li-like nickel L-shell Ions

The X-ray emission spectra of nickel plasma were simulated under the collisional radiative model (CRM) by using the flexible atomic code (FAC). The dynamical processes including collisional excitation (CE), radiative recombination (RR), dielectronic recombination (DR), collisional ionization (CI) and resonance excitation were considered in the model, and the rate coefficients of DR, RR as well as CI were consistent with previous results within 15%. It was found that the contributions to spectra from cascades and indirect processes could not be ignored. The intensities of spectral lines for lithium-like nickel L-shell ions are sensitive to the electron temperature. The good agreement between present spectral peaks and earlier observed results can be taken as a measure of the accuracy of the present work.     

氙激光等离子体的双电子复合过程研究(英文)

在自旋-轨道劈裂阵模型下,通过类铜的内壳层激发组态计算了类镍氙的双电子复合速率系数,其中考虑了共振和非共振辐射平衡跃迁对自电离能级的影响,而忽略了因碰撞跃迁引起的电子俘获,非共振辐射平衡跃迁在低电子温度条件下主要影响双电子复合过程;本文讨论了双电子复合系数及双电子伴线强度比随电子温度的变化.     

类镍金离子的双电子复合速率系数

 在自旋轨道劈裂阵模型下, 理论计算在0.02keV≤T≤10keV范围内,类镍金Au⁵¹⁺的3d⁹nln''l''(n''=4,5,6; l''=s,p,d,f)双电子复合速率系数,并分析了影响双电子复合速率系数的主要因素。