Weitere Messungen zur Anisotropie der intermolekularen Wechselwirkung durch Streuung von Molekülen in definiertem Quantenzustand

Improved measurements of the ratio of scattering cross sections for various molecular rotational states are reported for scattering of TlF in rotational states ¦J, M〉=¦1, 0〉 and ¦1, 1〉, and CsF in rotational states ¦2, 0〉 and ¦2, 2〉 by rare gases. The results are interpreted in terms of an angle dependent attractive potentialV=?2ε(r _m /r) ⁶(1+q ₆ P ₂(cosΘ) in which the repulsive part of the interaction is neglected. The “high energy” approximation is used to calculate the cross section, which contains the velocity dependence and the state dependence as factors. The experiments show for all scattering partners with the exception of He and Ne, that the state dependence is velocity independent. In those cases this result provides a justification for the neglect of the repulsive potential term. The results for the anisotropy parameterq ₆, which to a good approximation depends only on properties of the moleculus, are:q ₆=0.23±0.01 for TlF,q ₆=0.28±0.02 for CsF.