Fluorescence lifetimes of the [formula omitted], [formula omitted], R1Π g, and [formula omitted] states of H 2

Abstract

The rovibronic structures of gerade excited states of molecular hydrogen have been investigated between 117 000 cm −1 and the second dissociation limit with extreme ultraviolet visible double resonant excitation technique. Several levels have been unambiguously assigned to the v = 0 state of the 4 s and 4 d Rydberg members 4 s σ O 1 Σ g + , 4 d σ P 1 Σ g + , 4 dπ R 1Π g , and 4 dδ S 1Δ g . The fluorescence lifetimes have been measured under collision free conditions for the first time, revealing that the lifetimes for the O 1 Σ g + ( v = 0 ) state, 172.8 and 193.7 ns for J = 0 and 1, respectively, are much longer than those for the 4 d Rydberg states. The rotational dependence of the lifetimes for the EF + GK + H 1 Σ g + , I 1Π g , and J 1Δ g states is discussed in terms of the nonadiabatic coupling among the upper gerade manifolds.