Excitation of Meinel and the first negative band system at the collision of electrons and protons with the nitrogen molecule

摘要

The absolute cross sections for the e-N_2 and p-N_2 collisions for the first negative B~2∑_u~+–X~2∑_g~+ and Meinel A~2∏_u–X ~2∑_g~+ bands have been measured in the energy region of 400–1500 eV for electrons and 0.4–10 keV for protons, respectively. Measurements are performed in the visible spectral region of 400–800 nm by an optical spectroscopy method. The ratio of the cross sections of the Meinel band system to the cross section of the first negative band system (0,0) does not depend on the incident electron energy. The populations of vibrational levels corresponding to A~2∏_u states are consistent with the Franck-Condon principle. The ratios of the cross sections of (4,1) to (3,0) bands and (5,2) to (3,0) bands exhibit slight dependence on the proton energy. A theoretical estimation within the quasimolecular approximation provides a reasonable description of the total cross section for the first negative band.