Observation of atomiclike electronic excitations in pure He-3 and He-4 clusters studied by fluorescence excitation spectroscopy - art. no. 153403

The structure of the electronically excited states of He-3 and He-4 cluster s is investigated using fluorescence excitation spectroscopy. Distinct band s are observed energetically close to atomic 1s-ns, nd, np transitions and attributed to perturbed excited He atomiclike states with different princip le and orbital quantum numbers. The line shifts and widths of the bands of He-3 and He-4 clusters of the same size are different and correlate with th e average particle density inside the clusters calculated using the density functional method.