Structure of gaseous Kr in the low-q region by neutron scattering and interaction potentials

Accurate experimental information on the long-range triplet interactions in noble fluids, as well as on the two-body potential, can be obtained from t he low-density behavior of the static structure factor S(q) in the small-q region. The results here reported of a recent low-q neutron diffraction inv estigation in Kr, devoted to undercritical densities in the range 2.4<n/nm( -3)<4.3, provide important indications on the pair interactions and allow a lso a reliable analysis of irreducible three-body potential effects on the measured structure, from which the triple-dipole Axilrod-Teller strength is extracted with unprecedented accuracy. [S1063-651X(99)13511-6].