Angular distribution of electrons elastically scattered from gases: 1.5-400 eV onN2. II

Differential cross sections of electrons elastically (vibrationally) scattered from ${\mathrm{N}}_2$ have been measured by a crossed-beam method. Energy and angular range of the measurements are 1.5 to 400 eV and -96° to + 156°, respectively, with an emphasis on the ${\pi }_g$ shape-resonance region. The wide energy range of the measurements provides the basis for intercomparison of a large suite of similar measurements. The comparison shows generally good to excellent agreement. The comparison with theoretical calculations is less satisfactory with significant differences in the magnitudes of the cross sections and only fair agreement in shape. In the ${\pi }_g$ shape-resonance region, the elastic cross sections appear to be one-half of the total cross sections, approximately. Inelastic cross sections, mainly vibrational excitations, would thus appear to have a magnitude near that of the elastic cross section suggesting the importance of an independent measurement of vibrational-excitation cross sections in the region of the ${\pi }_g$ resonance.