Improved Laboratory Transition Parameters forEu II and Application to the Solar Europium Elemental and Isotopic Composition
Improved Laboratory Transition Parameters forEu II and Application to the Solar Europium Elemental and Isotopic Composition
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DOI：
10.1086/323407
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发表时间：
2001-12
期刊：
影响因子：
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通讯作者：
J. Lawler;M. Wickliffe;E. A. Hartog;C. Sneden
中科院分区：
文献类型：
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作者：
J. Lawler;M. Wickliffe;E. A. Hartog;C. Sneden
新的辐射寿命测量使用时间分辨激光诱导荧光报道的最低六个偶宇称水平的Eu II。分支分数，从傅里叶变换光谱测量，与这些寿命相结合，以确定最强的蓝色-紫外线和额外的黄色-红色线的Eu II的原子跃迁概率。这些结果与已发表的数据进行比较，一般良好的协议被发现。推荐的超精细结构常数和同位素位移，这些线也组装从文献和补充，根据需要，使用非线性最小二乘拟合的傅里叶变换光谱线轮廓的结果。这些实验室数据被应用于太阳Eu元素丰度的新测定，得到Elog 10 ε（Eu）ε = 0.52 ± 0.01，内部（散射）和外部（系统）不确定度分别估计为±0.04。通过对三条Eu Ⅱ谱线（主要是λ4129）的剖面分析，151 Eu和153 Eu的同位素分数与陨石物质中的值一致。
New radiative lifetime measurements using time-resolved laser-induced fluorescence are reported for the lowest six even-parity levels of Eu II. Branching fractions, measured from Fourier transform spectra, are combined with these lifetimes to determine atomic transition probabilities for the strongest blue-UV lines and additional yellow-red lines of Eu II. These results are compared with published data, and generally good agreement is found. Recommended hyperfine structure constants and isotopic shifts for these lines are also assembled from the literature and supplemented, as needed, using results from nonlinear least-squares fits of line profiles in Fourier transform spectra. These laboratory data are applied in a new determination of the solar Eu elemental abundance, yielding ⟨log10 ε(Eu)⟩ = 0.52 ± 0.01, with ±0.04 estimated for each of internal (scatter) and external (systematic) uncertainties. From analysis of the profiles of three Eu II lines, primarily λ4129, isotopic fractions of 151Eu and 153Eu are shown to be consistent with their values in meteoritic material.