标题： 在天体物理建模中热电子碰撞的Axelrod公式的应用 显示英文标题

标题： On the use of the Axelrod formula for thermal electron collisions in Astrophysical Modelling

摘要： 阿克塞尔罗德近似在天体物理建模代码中被广泛用于评估禁戒跃迁的电子碰撞激发有效碰撞强度。 此类近似方法对于许多具有开放壳层的重元素来说是必需的，因为碰撞数据要么不存在，要么稀少，而使用更可靠的方法则证明成本过高。 此类禁戒跃迁的原子数据对于生成不假设局部热力学平衡（LTE）的完整碰撞辐射模型至关重要。 在这篇简短的论文中，我们重复优化了简单阿克塞尔罗德公式的大量$R$-矩阵数据集，范围从铁和镍到第一r过程峰元素锶、钇和锆，再到更高Z系统的碲、钨、铂和金。 我们表明，对禁戒跃迁的近似处理可能在这样的碰撞辐射模型中成为显著的误差来源。 我们发现，不同系统和电荷状态的优化系数存在很大差异，尽管可以根据基态构型的轨道结构看到一些一般趋势。 这些趋势可能有助于未来在$R$-矩阵数据不可用的元素计算中做出更好的估计。 显示英文摘要

摘要： The Axelrod approximation is widely used in astrophysical modelling codes to evaluate electron-impact excitation effective collision strengths for forbidden transitions. Approximate methods such as this are a necessity for many heavy elements with open shells where collisional data is either non existent or sparse as the use of more robust methods prove prohibitively expensive. Atomic data for such forbidden transitions are essential for producing full collisional radiative models that do not assume Local-Thermodynamic-Equilibrium (LTE). In this short work we repeat the optimization of the simple Axelrod formula for a large number of $R$-matrix data sets, ranging from Fe and Ni to the first r-process peak elements of Sr, Y and Zr, to higher Z systems Te, W, Pt and Au. We show that the approximate treatment of forbidden transitions can be a significant source of inaccuracy in such collisional radiative models. We find a large variance of the optimized coefficients for differing systems and charge states, although some general trends can be seen based on the orbital structure of the ground-state-configurations. These trends could potentially inform better estimates for future calculations for elements where $R$-matrix data is not available.