High Resolution Laser Spectroscopy of H2at 86–90 nm

Abstract

A narrowband and tunable extreme ultraviolet laser source was employed to study the absorption spectrum of molecular hydrogen in the range 86–90 nm. Frequencies of transitions to theC1Πu,v= 6–10,D1Πu,v= 1,B′1Σ+u,v= 0–2, andB1Σ+u,v= 20, 22, 23, 25, 26, and 27 states were measured. In view of the hypothesis of theC1Πustates of H2as possible carriers of the diffuse interstellar bands the energies of these states were determined with high accuracy (0.02–0.06 cm−1).