MANY-BODY EFFECTS IN THE STATIC STRUCTURE OF DENSE KRYPTON AND XENON

The effects of many-body interactions in the static structure of dense gaseous krypton (for 0.9-2.1 rho(c), where rho(c) is the critical den sity) and xenon (for 2.2-2.6 rho(c)) were investigated in the momentum transfer range 4 less than or equal to Q less than or equal to 42 nm( -1), through comparisons of the measured structure factors S(Q) with t hose calculated through the MHNC-CRS integral equation by Reatto and T au. One property investigated is the small increase in the effective a tomic diameter with increasing density. While the observed variation, as determined through the position of the main diffraction maxima, is similar to that given by the inclusion of the Axilrod-Teller triple-di ploe interaction in the calculation, further small deviations exist wh ich indicate the need for additional many-body terms.