Deexcitation of helium 2 (3)S, 2 (1)S, and 2 (3)P atoms at Ar and Xe films.
Deexcitation of helium 2 (3)S, 2 (1)S, and 2 (3)P atoms at Ar and Xe films.
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Ar 和 Xe 薄膜上氦 2 (3)S、2 (1)S 和 2 (3)P 原子的去激发。
DOI：
10.1103/physreva.49.4703
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Walters
中科院分区：
文献类型：
--
作者：
Oró;Soletsky;Zhang;Dunning;Walters
发射电子能量分布的测量与电子自旋标记技术相结合，用于探测He(2 [sup 3][ital S]), He（2 [sup 1][ital S]）和He（2 [sup 3][ital P]）原子在冷却Cu（100）衬底上吸附的Ar和Xe膜上的退激机制。这两个表面的数据包含与气相潘宁电离观测到的特征相似的特征，表明喷射结果部分来自俄歇去激发，即表面潘宁电离。然而，对于Xe，可以观察到额外的特征，这可以归因于入射激发原子的共振电离，然后通过涉及薄膜中相邻Xe原子的相互作用产生的He[sup +]离子的中和。事实上，Xe的数据提供了一个特殊的例子，在一个表面上，俄歇去激发和共振电离是并行发生的，分支比随着入射原子的内能的增加而显著变化。Ar和Xe薄膜的发射电子产率都大大高于干净的Cu(100)，表明这些薄膜可能构成高效热能氦亚原子探测器的基础。
Measurements of ejected electron energy distributions are used in conjunction with electron spin labeling techniques to probe the mechanisms by which He(2 [sup 3][ital S]), He(2 [sup 1][ital S]), and He(2 [sup 3][ital P]) atoms are deexcited at Ar and Xe films adsorbed on a cooled Cu(100) substrate. The data for both surfaces contain features similar to those observed in gas-phase Penning ionization, indicating that ejection results, in part, from Auger deexcitation, i.e., surface Penning ionization. For Xe, however, additional features are observed that can be attributed to resonance ionization of an incident excited atom followed by neutralization of the resulting He[sup +] ion through an interaction that involves neighboring Xe atoms in the film. Indeed, the Xe data provide an exceptional example of a surface at which Auger deexcitation and resonance ionization occur in parallel with one another, with a branching ratio that changes significantly as the internal energy of the incident atoms increases. The ejected electron yield from both Ar and Xe films is substantially higher than for clean Cu(100), indicating that such films might form the basis of an efficient thermal-energy helium metastable-atom detector.