Relative flow technique and its application in the measurement of differential cross section by electron impact method

To improve the accuracy of the dynamic parameters of atoms and molecules, in this work the relative flow technique is applied to the fast electron impact method. Then the generalized oscillator strength (GOS) of 6s excitation of xenon was measured based on this technique. The present result is in good agreement with the previous ones in the small momentum transfer region, which indicates the validity of the relative flow technique. The momentum transfer dependence behavior of the apparent generalized oscillator strength of the 6s excitation on the electron impact energies in the large momentum transfer region shows that the first Born approximation is not reached at an impact energy of 500 eV. Compared with the calculation based on the Hartree-Fock approximation, the result calculated by the random phase approximation with exchange in which the electron correlation effect is taken into account more comprehensively is in better agreement with the experimental value in this work, which means that the electron correlation effect is important for the heavy atoms like Xe. (authors)