Energy levels, radiative rates and electron impact excitation rates for transitions in He-like Fe XXV, Co XXVI, Ni XXVII, Cu XXVIII and Zn XXIX
Energy levels, radiative rates and electron impact excitation rates for transitions in He-like Fe XXV, Co XXVI, Ni XXVII, Cu XXVIII and Zn XXIX
复制标题
DOI：
10.1088/0031-8949/87/05/055302
复制
发表时间：
2013-04
期刊：
影响因子：
2.9
通讯作者：
K. Aggarwal;F. Keenan
中科院分区：
文献类型：
--
作者：
K. Aggarwal;F. Keenan
我们计算了类氦Fe XXV、Co XXVI、Ni XXVII、CuXXVIII和ZXXIX的能级、辐射率和电子碰撞激发截面和跃迁速率。能级和辐射率的计算采用GRASP(通用相对论原子结构程序包)。为了确定碰撞强度和随后的激发率，使用了狄拉克原子R矩阵代码(DARC)。报告了每个离子的最低49个能级中的所有E1、E2、M1和M2跃迁的振子强度、辐射率和谱线强度。此外，还列出了上述五种离子的所有49个能级的理论寿命。碰撞强度在麦克斯韦速度分布上平均，并列出了在高达107.7 K的宽温度范围内获得的有效碰撞强度，并与使用灵活原子代码(FAC)获得的类似数据进行了比较，以突出包括在DARC计算中的共振在确定有效碰撞强度中的重要性。对于某些跃迁，还讨论了DARC和FAC碰撞强度之间的差异。最后，对于所有离子中的许多跃迁，在很大的电子温度范围内，用DARC代码计算的有效碰撞强度的结果与以前的半相对论R矩阵数据之间的差异被注意到。
We report calculations of energy levels, radiative rates and electron impact excitation cross sections and rates for transitions in He-like Fe XXV, Co XXVI, Ni XXVII, Cu XXVIII and Zn XXIX. The grasp (general-purpose relativistic atomic structure package) is adopted for calculating energy levels and radiative rates. For determining the collision strengths and subsequently the excitation rates, the Dirac atomic R-matrix code (darc) is used. Oscillator strengths, radiative rates and line strengths are reported for all E1, E2, M1 and M2 transitions among the lowest 49 levels of each ion. Additionally, theoretical lifetimes are listed for all 49 levels of the above five ions. Collision strengths are averaged over a Maxwellian velocity distribution and the effective collision strengths obtained listed over a wide temperature range up to 107.7 K. Comparisons are made with similar data obtained using the flexible atomic code (fac) to highlight the importance of resonances, included in calculations with darc, in the determination of effective collision strengths. Discrepancies between the collision strengths from darc and fac, for some transitions, are also discussed. Finally, discrepancies between the present results of effective collision strengths with the darc code and earlier semi-relativistic R-matrix data are noted over a wide range of electron temperatures for many transitions in all ions.