Experimental total collision cross sections in the glory region for noble gas systems

In a crossed supersonic beam apparatus measurements have been performed on the total cross section as a function of velocity in the thermal range for scattering of Ne, Ar, Kr and Xe by Ar, Kr and Xe. Apart from glory structure in the total cross section also ratios of absolute values of the non-glory total cross sections have been measured. For the analysis four quantities are introduced which are characteristic for the main aspects of total cross section data viz. the absolute value of the total cross section, the velocity dependence of the non-glory total cross section, the position of the glories and their amplitude. The four quantities are directly related to specific properties of the interaction. The various potentials proposed in the literature are tested correspondingly. The validity of combination rules for ϵ, rm and Qngl is examined. It is demonstrated that the long range noble gas interactions do not reduce to the same form.