The project concerns the study of small clusters of rare gas atoms; most importantly, He clusters. The "charge seeded expansion" method of producing Ar, Kr and Ne clusters will be used to study the "magic numbers" or highly structured mass spectrum generated by this method, while a separate He cluster source is developed. The structure and dynamics of He clusters will be studied (once produced) as a function of the number of atoms in the droplet. Using the dielectric resonance of an ion in a liquid drop, the dependence of the drop radius on mass and the dissipative behavior of drops will be studied. These data will provide information concerning the onset of superfluidity in He clusters of microscopic size.