Knowledge Bank

In an experiment combining $1XUV+1UV$ double resonance laser excitation in the presence of a small electric field with pulsed field ionization, bound states in the $1/r$ potential just below the $H+H-$ ionization (or dissociation) limit were observed. About $10cm-1$ below the limit the level density is so high that even for narrowband excitation $(\Delta \nu laser=300MHz)$ about 150 n-states are coherently excited. Experimentally, signal recurrences were observed as a function of delay of the field ionization pulse, that match the splittings between Stark states. A theoretical interpretation of the phenomena is presented fully based on the analysis of Rydberg states in the hydrogen atom, in which the electron is replaced by the heavier $H-$ particle.