ELASTIC ELECTRON-SCATTERING FROM HELIUM - ABSOLUTE EXPERIMENTAL CROSS-SECTIONS, THEORY AND DERIVED INTERACTION POTENTIALS

We report new differential cross section measurements (E0 = 1.5-50 eV) and coupled channel optical model calculations for elastic scattering of electrons from helium. The experimental results, from a crossed electron-atomic beam apparatus, are analysed via a complex phase-shift technique with the derived phase-shifts, and their associated errors, then being used to derive total elastic, total reaction, total momentum transfer and grand total cross sections, and their respective errors, in a mathematically rigorous manner. Further, we have applied fixed-energy inverse scattering techniques to the present data in order to deduce the interaction potential between the colliding particles.