Electron impact cross sections for ν=0→1 vibrational excitation of N2at electron energies from 3 to 30 eV

Normalised, absolute electron impact differential cross sections (DCS) for the (0 to 1) vibrational excitation of N 2 , for incident electron energies from 3 to 30 eV, have been measured with the help of a crossed beam apparatus over the angular range of 20 to 130 degrees . The l=3 (f wave) contribution was found to dominate the vibrational excitation at incident energies in the range 18 to 25 eV. From the DCS, the integral and momentum transfer cross sections were calculated. It could also be verified that the enhanced vibrational excitation due to the sigma u shape resonance has a peak value at about 21 eV with a full width at half maximum of about 7 eV. The DCS and the integral cross sections are compared with recent theoretical calculations of the converged rotational close coupling and the vibrational sudden approximation, as well as with the continuum multiple-scattering method.