Time-Differential Ground-State Hanle Effect in Fast-Beam Laser Spectroscopy

Abstract

Optical pumping in fast ion-beam collinear laser spectroscopy is used to study the time evolution of oriented metastable state populations in an external magnetic field. A theoretical description of this time-differential ground-state Hanle effect is presented. The possibility to measure ionic ground- and metastable-state $g$ factors is illustrated by a measurement of the $g$-factor ratio of the $5d{}_{}{}^2{}_{}{}^{}D_{\frac{3}{2}}^{}{}_{}{}^{}$ and $5d{}_{}{}^2{}_{}{}^{}D_{\frac{5}{2}}^{}{}_{}{}^{}$ states in ${\mathrm{Ba}}^{+}$.