Explicit Form of the Radiative and Collisional Branching Ratios in Polarized Radiation Transport with Coherent Scattering
Explicit Form of the Radiative and Collisional Branching Ratios in Polarized Radiation Transport with Coherent Scattering
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相干散射偏振辐射传输中辐射和碰撞分支比的显式形式
DOI：
10.3847/1538-4357/aa8a73
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
R. M. Sainz
中科院分区：
文献类型：
--
作者：
R. Casini;T. D. P. Alemán;R. M. Sainz
我们考虑了Λ型原子跃迁中偏振辐射传输的矢量发射率，我们最近提出用它来解释散射辐射的完全频率再分布（CRD）和部分频率再分布（PRD）贡献。这个表达式可以简明地写为ε=（ε（1）-ε f. s. (2))+ε（2），其中ε（1）和ε（2）分别是描述Λ型原子中的单光子和双光子过程的发射率项，并且其中“f.s.”这意味着必须假设入射辐射在谱线上的适当的“平坦谱”平均值来评估相应的项。在这个后续的研究中，我们明确地考虑这些不同的条款的表达的情况下，一个极化的多项原子推导出的代数形式的CRD和PRD的贡献之间的分支比的发射率。在低阶项为非相干项的二项原子的极限下，我们的结果与Bombardian最近导出的结果完全一致。
We consider the vector emissivity of the polarized radiation transfer in a Λ-type atomic transition, which we recently proposed to account for both complete frequency redistribution (CRD) and partial redistribution (PRD) contributions to the scattered radiation. This expression can concisely be written as ε=(ε(1)−εf.s.(2))+ε(2), where ε(1) and ε(2) are the emissivity terms describing, respectively, one-photon and two-photon processes in a Λ-type atom, and where “f.s.” means that the corresponding term must be evaluated assuming an appropriate “flat spectrum” average of the incident radiation across the spectral line. In this follow-up study, we explicitly consider the expressions of these various terms for the case of a polarized multi-term atom to derive the algebraic forms of the branching ratios between the CRD and PRD contributions to the emissivity. In the limit of a two-term atom with non-coherent lower term, our results are shown to be in full agreement with those recently derived by Bommier.