Lifetime of the1s2(P11)and1s4(P13)levels of neon by the cascade Hanle effect

Abstract

The theory of the cascade level-crossing effect as formulated by Happer is evaluated for zero-nuclear-spin atomic systems and extended to include the case of a polarized initial state. We have used this theory to interpret our cascade-Hanle-effect results (zero-field level crossings) to obtain the lifetime of the two resonance levels, $1{s}_{2}(^{1}P_{1})$ and $1{s}_{4}(^{3}P_{1})$, of the $2{p}^{5}3s$ configuration of neon. The resonance lines 744 \AA{} ($1{s}_{4}\ensuremath{-}^{1}S_{0}$) and 736 \AA{} ($1{s}_{2}\ensuremath{-}^{1}S_{0}$) are produced in the cascade to the ground $^{1}S_{0}$ state when a beam of metastable $1{s}_{3}(^{3}P_{0})$ and $1{s}_{5}(^{3}P_{2})$ neon atoms is excited by selected lines of the $2{p}^{5}3s\ensuremath{-}2{p}^{5}3p$ transition array. Our results are $\ensuremath{\tau}(1{s}_{2})=1.65\ifmmode\pm\else\textpm\fi{}0.16$ nsec and $\ensuremath{\tau}(1{s}_{4})=20.5\ifmmode\pm\else\textpm\fi{}1.5$ nsec.