Rotational state selective photoionization of the H2 molecule from <i>B</i> 1Σ+<i>u</i>(<i>v</i> ′=0,3) states

Abstract

Selective photoionization from single rotational states of the B 1Σ+u(v′=0 and 3) excited state of the H2 molecule has been investigated with fixed frequency and tunable laser radiation around λ=266 nm. State selection of the B-state levels was achieved by tunable VUV laser excitation around λ=110 and 106 nm, respectively. The ionization cross section has been determined for different states, and found to be critically dependent upon the initial rotational quantum state and to show pronounced spectral structure with the ionization wavelength. At λI=266.05 nm the cross section varies between 0.23×10−18 and 1.2×10−18 cm2, depending on the initial state.