Depolarization effects in electron spin polarization of ~4He~+ ion beam

摘要

Spin polarization of He~+ ions in Penning ionization of optically pumped He metastable atoms (He~*(2~3S_1)) has been investigated. It was indicated that radiation trapping is a predominant depolarization effect in the He pressure range below 100 Pa. A drastic drop of He~* polarization was observed below the He pressure of 10 Pa. The He~+ polarization was estimated to be 16.6 ± 3.1% from the spin dependence of the electron spectra obtained on a magnetized sample surface (spin-polarized ion neutralization spectroscopy).