9306316 Lafyatis This proposal is for an experimental investigation of the van der Waals interaction between a ground state alkali atom and a conducting macroscopic surface. The goals of the investigation are: a) to resolve a long standing discrepancy between the only previous study of this nature and what is widely regarded as a reliable theoretical treatment b) to make benchmark measurements to maximally challenge the theories for these fundamental interactions c) to make the first measurements of the van der Waals potential energy function for atom-surface distances where retardation effects are important. The proposed experiment consists of passing a laser slowed atomic beam over an extremely flat gold surface and measuring downstream the density of the beam bent by van der Waals forces into the geometric shadow of the surface. By using laser slowing and working with near atomically flat surfaces the experiment will make measurements for atom- surface distances from 10 nm to 850 nm. The proposed experiments complement the ongoing Rydberg atom-gold surface studies of Hinds and Haroche. The proposed work will directly address the long standing experiment-theory discrepancy. The physics of a ground state atom's interaction with a conducting surface differs in important ways from that of a Rydberg atom's interaction.
