Dominance of angular momentum exchange in the PCI recapture of photoelectrons revealed by high resolution Auger electron measurements of Kr
Dominance of angular momentum exchange in the PCI recapture of photoelectrons revealed by high resolution Auger electron measurements of Kr
复制标题
Kr 的高分辨率俄歇电子测量揭示了 PCI 光电子重捕获中角动量交换的主导地位
DOI：
10.1088/1361-6455/ab4c1a
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
F Koike and Y Azuma
中科院分区：
文献类型：
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作者：
S Kosugi;N Suzuki;N Kumagai;H Iwayama;E Shigemasa;F Koike and Y Azuma
通过碰撞后相互作用（PCI）引起的光电子重捕获过程，发现了双光电离连续体中出乎意料的显着角动量交换效应。源自 3d− 1 5/2 光电离的 Kr (M 5 N 2, 3 N 2, 3) 俄歇电子谱是通过调谐到非常接近电离阈值之上的光子能量来测量的。当光子能量接近 3d− 1 5/2 光电离阈值时，通过将光电子重新捕获到高位最终离子轨道中，在俄歇峰轮廓内形成了包括多个角动量分量的里德伯系列结构。我们的谱线宽度比相应核心激发态的寿命宽度窄得多，使我们能够非常清楚地解析由于轨道角动量态而产生的详细结构。出乎意料的是，我们发现源自光电子和俄歇电子之间通过 PCI 进行角动量交换的共轭峰在光谱中占主导地位。通过直接光电离与 Kr 的价光电子能谱进行比较证实了新的分配。还发现共轭峰与高里德伯级数 Kr+ 4p− 2 (1 S 0, 1 D 2) ml 获得的量子缺陷值一致。将新的分配扩展到低于阈值的光子能量可能需要修改先前对共振俄歇过程的解释。
An unexpectedly prominent angular momentum exchange effect in the double photoionization continuum was identified through the photoelectron recapture process induced by post-collision interaction (PCI). The Kr (M 5 N 2, 3 N 2, 3) Auger electron spectrum originating from 3d− 1 5/2 photoionization was measured with the photon energy tuned very close above the ionization threshold. As the photon energy approached the 3d− 1 5/2 photoionization threshold, Rydberg series structures including several angular momentum components were formed within the Auger peak profile by the recapture of the photoelectrons into high-lying final ion orbitals. Our spectrum with line-width much narrower than the lifetime width of the corresponding core excited state allowed us to resolve detailed structures due to the orbital angular momentum states very clearly. Unexpectedly, conjugate peaks originating from the exchange of angular momentum between the photoelectron and the Auger electron through PCI were found to dominate the spectrum. Comparison with valence photoelectron spectrum of Kr via direct photoionization confirms the new assignment. Conjugate peaks were also found to be in accord with the quantum defect values obtained for the high Rydberg series Kr+ 4p− 2 (1 S 0, 1 D 2) ml. Extension of the new assignments to photon energies below threshold may call for the revision of previous interpretations of resonance Auger processes.