Rotational State Distribution of HBr+ Ions Formed by Resonance Enhanced Multiphoton Ionization

Abstract

Abstract The rotational state distribution of HBr+ ions formed via a large number of pump lines in the f 3Δ2 ← 1Σ and the F 1Δ2 ← 1Σ REMPI spectrum has been derived from the analysis of state-selective predissociation spectra. For most pump lines in the two REMPI spectra molecular ions are formed in narrow state distributions with dominant contributions of two or three different rotational states. By choice of the appropriate pump line in the REMPI spectrum this state distribution can be shifted from N = 0 to about N = 10. The data provide evidence that REMPI spectroscopy is a viable tool for the formation of state-selected molecular ions.