Molecular-frame EELS experiment on inner-valence ionization of N₂

We report molecular-frame electron scattering cross sections of N₂, obtained using an electron-ion coincidence technique. The vector correlation between the scattered electron and the fragment ion has been measured at incident electron energy of 1.4 keV for inner-valence ionization of N₂. The angular distributions of the electron scattering cross sections thus obtained exhibit clear momentum transfer dependence, indicating the significant change of the ionization dynamics due to contributions from electric multipole transitions. (paper)