Excitation and emission in the nitrogen band spectrum

It has previously been shown that the relative intensities of the 0 → 2, 1 → 3, and 2 → 4 second positive nitrogen bands excited by electronic impact are not changed when the energy of the exciting electrons is varied between 30 and 160 electron volts. The observed variations for energies between 14 and 30 electron volts were quantitatively explained by taking into consideration the effect of the energy separation of the initial vibration levels. A theory of molecular excitation by electronic impact was developed (II), and calculations of the relative excitation and emission probabilities were made. These were based on Hutchisson’s treatment of theharmonic oscillator. The “complete” intensities obtained by combining the two probabilities agreed quite well with the observed values. This article gives the results of measurements of the intensities of nine additional second positive bands for various exciting electron energies between 14 and 160 electron volts.