The FERRUM project: metastable lifetimes in Cr II
The FERRUM project: metastable lifetimes in Cr II
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FERRUM 项目：Cr II 的亚稳态寿命
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
H. Nilsson
中科院分区：
文献类型：
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作者：
E. Bäckström;J. Gurell;P. Royen;S. Mannervik;L. Norlin;R. Blackwell;H. Hartman;H. Nilsson
在低密度天体物理等离子体光谱中观察到了亚稳能级的宇称禁戒辐射跃迁。这些线被用作物理条件的探针，由于其上能级的长寿命而成为可能。FERRUM项目旨在获得铁族元素的新的和准确的原子数据，该项目的一部分涉及禁线。测量了单电离态铬的亚稳能级3d 4（a3 D）4sc 4D 5/2和3d 4（a3 D）4sc 4D 7/2的辐射寿命。该实验是在离子储存环CHRING上进行的。我们采用了激光探测技术测量长寿命。在这篇文章中，我们给出了这两个能级的寿命分别为t5/2= 1.28（16）s和t7/2= 1.37（7）s。与以前的理论工作的比较显示出良好的一致性和结果进行了讨论的理论背景下。
Parity forbidden radiative transitions from metastable levels are observed in spectra of low-density astrophysical plasmas. These lines are used as probes of the physical conditions, made possible due to the long lifetime of their upper level. In a joint effort, the FERRUM project aims to obtain new and accurate atomic data for the iron-group elements, and part of this project concerns forbidden lines. The radiative lifetimes of the metastable energy levels 3 d4(a 3 D)4 s c4 D 5/2 and 3 d4(a 3 D)4 s c4 D 7/2 of singly ionized chromium have been measured. The experiment has been performed at the ion storage ring CRYRING. We employed a laser-probing technique developed for measuring long lifetimes. In this article, we present the lifetimes of these levels to be t5/2= 1.28(16) s and t7/2= 1.37(7) s, respectively. A comparison with previous theoretical work shows good agreement and the result is discussed in a theoretical context.