Electron-impact excitation of Fe II
Electron-impact excitation of Fe II
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Fe II 的电子碰撞激发
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
P. Burke
中科院分区：
文献类型：
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作者：
C. Ramsbottom;C. Noble;V. Burke;M. Scott;P. Burke
本文报道用并行R矩阵程序PRMAT计算Fe Ⅱ电子碰撞激发的精确总碰撞强度和有效碰撞强度。对应于3d 64 s、3d 7、3d 64 p和3d 54 s4 s基础配置的目标状态被包括在计算中，从而引起113 LS状态354耦合通道问题。在详细系统地研究了目标态和碰撞波函数中的相关效应之后，发现需要在组态相互作用展开中包括另外21个组态函数，以获得更精确的目标态和碰撞波函数。这个大大改进的26位形模型已被用来计算收敛的总有效碰撞强度的所有六重态到四重态跃迁之间的这些水平与总自旋S = 2，给出了1785条线。这些计算为研究电子与其它铁峰元素的低电离级碰撞奠定了基础。这项工作已进一步扩大与Breit-Pauli相对论计算的一个较小的模型开始，包括262精细结构水平和1800多个耦合通道。与此同时，PRMAT并行R-矩阵包正在扩展到包括相对论效应，这将使我们能够尝试更复杂的26配置模型，并首次产生所需的原子数据的数量和质量进行有意义的合成的Fe II光谱。
We report in this paper the computation of accurate total collision strengths and effective collision strengths for electron-impact excitation of FeII, using the parallel R-matrix program PRMAT. Target states corresponding to the 3d64s, 3d7, 3d64p and 3d54s4s basis configurations were included in the calculations giving rise to a 113 LS state 354 coupled channel problem. Following a detailed systematic study of correlation effects in both the target state and collision wavefunctions, it was found that an additional 21 configuration functions needed to be included in the Configuration Interaction expansion to obtain significantly more accurate target states and collision wavefunctions. This much improved 26-configuration model has been used to calculate converged total effective collision strengths for all sextet to quartet transitions among these levels with total spin S = 2, giving a total of 1785 lines. These calculations have laid the foundation for an approach which may be adopted in the study of electron collisions with the low ionization stages of other iron peak elements. The work has been further extended with the commencement of a Breit-Pauli relativistic calculation for one of the smaller models and includes 262 fine-structure levels and over 1800 coupled channels. At the same time the PRMAT parallel R-matrix package is being extended to include relativistic effects which will allow us to attempt the more sophisticated 26-configuration model and produce for the first time the amount and quality of atomic data required to perform a meaningful synthesis of the Fe II spectrum.