[en] In the study of atomic structure, an important class of observations comes from the scattering of low energy electrons by low density atomic beams. Techniques for performing such experiments and studies of elastic scattering resonance phenomena in the rare gases are described. The result has been the creation of a unique and well understood hemispherical electron gun. Design and performance of the electron gun are discussed. Measurements at several angles have been made of the shape of the elastic scattering resonances occurring in neon and argon just below the inelastic threshold, and the results have been used to determine, numerically, values for the atomic structure parameters that are involved in the scattering resonances. The scattering data taken at scattering angles of 54⁰ and 90⁰ have been used for each of the two gases to determine the first four phase shifts, the scattering resonance widths and separations, and the instrumental resolution width