Energy levels, radiative rates and electron impact excitation rates for transitions in He-like Mg XI, Al XII, P XIV and S XV
Energy levels, radiative rates and electron impact excitation rates for transitions in He-like Mg XI, Al XII, P XIV and S XV
复制标题
类 He Mg XI、Al XII、P XIV 和 S XV 跃迁的能级、辐射速率和电子碰撞激发速率
DOI：
10.1088/0031-8949/85/02/025305
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发表时间：
2012
期刊：
影响因子：
2.9
通讯作者：
Aggarwal K
中科院分区：
文献类型：
--
作者：
Aggarwal K
我们报告了类 He Mg XI、Al XII、P XIV 和 S XV 中能级、辐射速率和电子碰撞激发截面以及跃迁速率的计算。采用GRASP（通用相对论原子结构包）代码来计算能级和辐射率。为了确定碰撞强度以及随后的激发速率，使用狄拉克原子 R 矩阵代码 (DARC)。报告每个离子最低 49 个能级中所有 E1、E2、M1 和 M2 跃迁的振荡器强度、辐射速率和线强度。碰撞强度在麦克斯韦速度分布上进行平均，并在高达 10 7.2 K 的宽温度范围内列出获得的有效碰撞强度。与从灵活原子代码 (FAC) 获得的类似数据进行比较，以强调共振（包括在 DARC 计算中）在确定有效碰撞强度中的重要性。还讨论了 DARC 和 FAC 碰撞强度之间的差异，特别是禁止跃迁的碰撞强度。此外，还列出了上述四种离子的所有 49 个能级的理论寿命。
We report calculations of energy levels, radiative rates and electron impact excitation cross sections and rates for transitions in He-like Mg XI, Al XII, P XIV and S XV. The GRASP (general-purpose relativistic atomic structure package) code is adopted to calculate energy levels and radiative rates. To determine 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. Collision strengths are averaged over a Maxwellian velocity distribution and the effective collision strengths obtained are listed over a wide temperature range up to 10 7.2 K. Comparisons are made with similar data obtained from 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, particularly for forbidden transitions, are also discussed. Additionally, theoretical lifetimes are listed for all the 49 levels of the above four ions.