Studies Involving Metastable Helium Atoms (Physics)

He （2.3S）亚稳原子的新性质将构成本研究计划的主题。电子自旋标记技术将用于探索在光抽运氦余辉装置中涉及He（2.3S）原子的Penning电离反应动力学，该装置也将用于研究极化电子与0.2等开壳层目标之间碰撞的自旋交换。利用新开发的激光对He（2.3S）电子自旋进行光学定向，还将研究流动氦余辉作为极化电子源的性能。He（2.3S）中自旋角动量守恒。本文将利用交叉束流装置中具有闭壳伙伴的Penning反应，为电子自旋极化计的绝对校准提供一种新技术。He（2.3S）原子在液氦表面的相互作用将被研究，期望He（2.3S）原子将被困在液氦表面。将尝试通过使He（2.3S）原子自旋极化来改变这些相互作用。

The novel properties of He (2.3S) metastable atoms will form the theme of this research program. Electron spin labelling techniques will be used to explore the dynamics of Penning ionization reactions involving He(2.3S) atoms in an optically pumped flowing helium afterglow apparatus, which will also be used to investigate spin exchange in collisions between polarized electrons and open shell targets such as 0.2. The performance of the flowing helium afterglow as a source of polarized electrons will also be investigated utilizing newly developed lasers to optically orient the He(2.3S) electron spins. Conservation of spin angular momentum in He(2.3S). Penning reactions with closed shell partners will be exploited in a crossed beam apparatus to provide a new technique for absolute calibration of electron spin polarimeters. The interactions of He(2.3S) atoms at a liquid helium surface will be investigated, with expectation that the He(2.3S) atoms will be trapped there. Attempts will be made to modify these interactions by spin polarizing the He(2.3S) atoms.