Quantum physics of He near the double ionization threshold-quantum chaos and Wannier threshold law

He近双电离阈值的量子物理——量子混沌与万尼尔阈值定律

• 批准号: 0555052
• 负责人: Chii Dong Lin
• 金额: --
• 依托单位: Kansas State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2010-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0555052&HistoricalAwards=false
• 关键词: Quantum; physics; He; near; double

The proposed research includes three topics.The first is to study the level statistics of He and other atoms in relation to the questions of quantum chaos. The second is the study of the photoabsorption spectra of He in the energy region lying between the N=10-25 thresholds of He+. Until now both the theoretical and experimental investigations for the photoabsorption of He have been limited to about the N=9 threshold of He+. This energy region will become accessible as more intense light sources such as those from free electron XUV and soft-X-ray lasers come on line in a few years. Questions such as whether the photoabsorption spectra will exhibit Erickson fluctuations in the quantum chaos regime will be investigated. The third topic concerns the absolute double photoabsorption cross sections of He for energies near the double electron escape threshold. Calculations will be undertaken from about a few meV above the threshold to test the Wannier threshold law. No full ab inito calculations as yet have been able to probe the energy region within about 1 eV above the threshold.

研究内容包括三个方面：第一，研究He等原子的能级统计与量子混沌问题的关系; 第二部分研究了He ~+在N=10-25阈值之间的光吸收谱。到目前为止，He的光吸收的理论和实验研究都局限于He+的N=9阈值。随着更强的光源，如自由电子XUV和软X射线激光器在几年内上线，这个能量区域将变得可用。诸如光吸收光谱是否会在量子混沌状态下表现出埃里克森波动等问题将被研究。 第三个主题涉及的绝对双光吸收截面的能量附近的双电子逃逸阈值。 计算将从阈值以上约几个meV进行，以测试Wannier阈值定律。 没有完整的从头算计算尚未能够探测的能量范围内约1 eV以上的阈值。