Energy levels, radiative rates and electron impact excitation rates for transitions in He-like Ga XXX, Ge XXXI, As XXXII, Se XXXIII and Br XXXIV
Energy levels, radiative rates and electron impact excitation rates for transitions in He-like Ga XXX, Ge XXXI, As XXXII, Se XXXIII and Br XXXIV
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DOI：
10.1088/0031-8949/87/04/045304
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发表时间：
2013-03
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
我们报告的能级，辐射率和电子碰撞激发截面和类氦镓XXX，锗XXXI，作为XXXII，硒XXXIII和溴XXXIV的跃迁率的计算。计算能级和辐射率采用grasp（通用相对论原子结构软件包）。为了确定碰撞强度和随后的激发速率，使用狄拉克原子R矩阵代码（darc）。振子强度，辐射率和线强度的所有E1，E2，M1和M2跃迁的最低49个级别的每个离子的报告。此外，提供了上述五种离子的所有49个水平的理论寿命。碰撞强度的平均超过麦克斯韦速度分布和有效的碰撞强度得到列出了一个广泛的温度范围高达108 K。与使用灵活的原子代码（fac）得到的类似数据进行比较，以突出共振的重要性，包括在计算与darc，在确定有效的碰撞强度。讨论了darc和fac碰撞强度的差异，特别是对某些禁戒跃迁的差异。最后，在所有离子的许多跃迁的广泛电子温度范围内，注意到目前使用darc代码计算的有效碰撞强度结果与早期半相对论R矩阵数据之间的差异。
We report calculations of energy levels, radiative rates and electron impact excitation cross sections and rates for transitions in He-like Ga XXX, Ge XXXI, As XXXII, Se XXXIII and Br XXXIV. 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 provided 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 108 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, particularly for some forbidden transitions, are also discussed. Finally, discrepancies between the present results for 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.