Absolute absorption coefficients of nitrogen in the vacuum ultraviolet.

Abstract

Absorption in nitrogen at wavelengths longer than 796A, the Worley-Jenkins Rydberg series limit 2∑g+, was found to be principally the result of band spectra, whereas below this limit continuous absorption set in, very rapidly reaching a first maximum of k=680 cm−1 near 760A and a second one near the limit of the Hopfield Rydberg series 2∑u+. From the appearance of the contour of the absorption continuum and from the intensity distribution of the preceding bands, one is led to believe that it was a composite one consisting of two ionization continua adjoining the two Rydberg series limits. The integrated absorption coefficient gave an f-value of 3.3 which was in agreement with the predicted value of 3.27 from classical electron theory. Between 796A and 661A some very large absorption coefficients were found with k=2.76×103 cm−1 because of the strong, diffuse bands in this region. Experimental results were internally consistent to about ten percent and Beer’s law was shown to be obeyed.