Photoionization and Spectroscopy of Atoms and Molecules

活动的主要领域将是研究卤素原子的电子动力学，包括核电子和价电子。卤素原子外层p壳层缺少一个电子，是一个原型的开壳层元素，对这些原子中的电子动力学的理解是在多重能级上表征电子运动的基础。将进行的实验是通过同步加速器辐射源和原子靶源的进展而成为可能的，这些进展允许在前所未有的分化程度上阐明电子动力学的细节。在LS多重能级上的衰变过程的隔离是实验的常规特征，而在J精细结构能级上的隔离，实验显示由于自旋轨道耦合而存在显著的影响，将被强调。本研究计划的主题是研究电子相关的细节，因为它体现在开壳原子和双激发原子的电子运动动力学中。该计划的主要目标是研究那些各向异性势对电子运动的影响尚未在适合于开壳结构的详细水平上进行探测的元素。提出的实验构成了对这些复杂多体系统的现有理论预测的第一次深入检查，旨在推动更先进理论模型的发展。对原型三体系统氦的双激发的一系列测量将补充主要工作，而对激发态亚稳原子动力学的详细研究将为今后的研究方向奠定基础。

The principal area of activity will be on the study of electron dynamics in the halogen atoms, both the core and the valence electrons. The halogen atom, with one missing electron in the outer p-shell, is a prototype open-shell element, and an understanding of the electron dynamics in these atoms is fundamental to the characterization of electron motion at the multiplet level. The experiments which will be carried out are made possible through advances in synchrotron radiation sources and atomic target sources which allow for the elucidation of the details of electron dynamics at an unprecedented degree of differentiation. Isolation of decay processes at the LS multiplet level are a routine feature of the experiments, and isolation at the J fine-structure level, where experiments reveal the presence of significant effects due to spin-orbit coupling, will be stressed. This research program has the general theme of studying the details of electron correlation as it is manifest in the dynamics of electron motion in open-shell and doubly excited atoms. The main thrust of the program is toward the study of those elements in which the influence of the anisotropic potential on the motion of the electrons has yet to be probed at the detailed level appropriate to an open-shell structure. The proposed experiments constitute the first indepth examination of the predictions of existing theories for these complex many-body systems and are aimed at giving impetus to the development of more advanced theoretical models. An accompanying set of measurements on the double excitations in helium, the prototype three-body system, will supplement the principal effort, and the detailed examination of dynamics of excited- state metastable atoms will set the stage for the future direction for the research.