Differential cross sections at0°and180°for electron-impact excitation of theE3Σg+state ofN2

Abstract

Relative differential cross sections at forward and backward angles for excitation of the E ${}^{3}{\ensuremath{\Sigma}}_{g}^{+}$ state of ${\mathrm{N}}_{2}$ have been measured in the resonant, near threshold energy region. Measurements are performed by using a double trochoidal electron spectrometer and are calibrated on the absolute scale by simultaneous measurements of this process and vibrational excitation of the ground state of ${\mathrm{N}}_{2}$ via ${}^{2}{\ensuremath{\Pi}}_{g}$ resonance. The contributions at $0\ifmmode^\circ\else\textdegree\fi{}$ and $180\ifmmode^\circ\else\textdegree\fi{}$ are separated by electron beam modulation and time-of-flight detection of scattered electrons. Obtained results confirm directly theoretical predictions of the symmetry of angular distribution of scattered electrons from ${}^{2}{\ensuremath{\Sigma}}_{u}^{+}$ resonance.