Absolute cross sections for electron excitation of the second positive bands of nitrogen

Absolute excitation cross sections for the emission of the second positive bands of nitrogen under electron impact have been obtained. Peak level cross sections for the νprime = 0, 1, 2 levels of the c 3 II u state were found to be, respectively, 23·5 × 10 -18 cm 2 , 14·4 × 10 -18 cm 2 and 4·9 × 10 -18 cm 2 . Good agreement is found with the theoretical A coefficients for the relative intensities of the different vibrational bands. The results are compared with those of other workers and various secondary effects which were observed are discussed.