Spectroscopy of the hydrogen molecular ion at its dissociation limit

Abstract
Previous theoretical and experimental work on the ion and its deuterium isotopes HD+ and D£ is briefly reviewed. Spectroscopic studies of the vibration rotation levels are discussed, and recent work on the infrared photodissociation of the high-lying vibrational levels is described. Earlier work that made use of ion-beam techniques to study the vibration—rotation levels of HD+ is reviewed, and compared with the most recent theoretical predictions. The nuclear-hyperfine and spin—rotation structure of HD+ is described, and recent observations of the vibration-rotation satellite lines that will yield absolute values of the deuterium hyperfine constants are presented. We conclude by describing our attempts to observe radiofrequency—infrared double-resonance spectra.