Differential elastic scattering of electrons by the rare gases

Differential cross sections for the elastic scattering of electrons by helium have been measured in the angular range 20 degrees -90 degrees and the energy range 1.5-100 eV. Absolute calibrations from phase shift determinations at 19.1 eV and via normalization to the data of Vriens et al. (1968) and Chamberlain et al. (1970) at 100 eV are in agreement to 2%. The estimated accuracy of the cross sections is +or-12%. A detailed description of the experimental procedure is given and the results are compared with other recent experimental results and theoretical calculations.