Collinear laser-ion beam determination of hfs in Cs II

Abstract By making use of the “velocity bunching” effect in collinear laser-ion beam spectroscopy, the hfs of the 5 p 5 2 P 3 2 5 d [ 3 2 ] 0 2 → 2 P 3 2 6 p [ 3 2 ] 2 transition in Cs II has been determined. A 30% reduction in linewidth compared with measurements using perpendicular laser-ion beam geometry is observed. The results for the 6 p [ 3 2 ] 2 level are compared with semi-empirical calculations.