THE F RYDBERG SERIES IN THE ABSORPTION-SPECTRUM OF N-2

The nf Rydberg levels of N-14(2) converging to the X (2) Sigma(g)(+) g round state of N-2(+) have been studied from n=4-9 in the high-resolut ion absorption spectra of supersonically expanding nitrogen at wavelen gths ranging from 843.2 to 802.6 Angstrom (118 600-124 600 cm(-1)). Th e best experimental results, achieving rotational temperatures on the order of 20 to 40 K and a resolution of 0.5 cm(-1), were obtained by p hotographing the jet absorption against the background continuum from a synchrotron radiation source. Complementary data for N-14(2) and N-1 5(2) come from the analyses of spectra recorded under equilibrium cond itions at 70 K with a resolution of 1 cm(-1), using the He continuum a s background source. The observations are interpreted with the help of multichannel quantum defect calculations and lead to the conclusion t hat, to varying degrees and with the exception of 4f(v=0), all the com plexes studied here show the effects of interactions with core excited d and s Rydberg levels built on the A (IIu)-I-2 first excited state o f N-2(+). Also, the 9f(v=0) complex is shown to be perturbed by 10p(v= 0), and the strength of the p-f interaction, has been determined.