Absolute optical cross sections for the excitation from the X2Σσ+ ground state of N2 by electron impact have been measured for 39 N2 first positive bands (B3IIσ-A3Σu+), 12 N2+ first negative bands (B3Σu-X2Σσ+), and 10 N2+ Meinel bands (A2IIu-X3Σσ+). Relative excitation functions are presented for N2 first negative bands with v′ values from 0 through 9 for 0 to 50 eV, for the (0,0) and (1,0) N2+ first negative bands for 0 to 450 eV, and for the (3,0) and (4,1) N2+ Meinel bands for 0 to 450 eV. The first-positive excitation functions exhibit sharp peaks at 10–12 eV and at 14–15 eV and exhibit an S-shaped change in slope about midway between onset and the maximum of the first sharp peak. The first negative and Meinel excitation functions have broad maxima at about 120 eV and 100 eV.
PAUL N. STANTON and ROBERT M. ST. JOHN, "Electron Excitation of the First Positive Bands of N2 and of the First Negative and Meinel Bands of N2+," J. Opt. Soc. Am. 59, 252-260 (1969)