LONG-RANGE INTERACTIONS IN XENON

The small-k behavior of the static structure factor S(k) in a noble ga s fluid is related to the two- and three-body part of the long-range i nteratomic potential, the London and Axilrod-Teller interaction, respe ctively. We have measured the S(k) of xenon at room temperature and fo ur low densities by means of a small angle neutron diffractometer. A c areful data analysis has allowed the determination of the strength of the long-range pair potential as well as the clear detection of the th ree-body effect, whose intensity has been directly obtained.