ABSORPTION-SPECTROSCOPY OF AR2(5P) IN THE 3-SIGMA-G AND 3-PI-G STATES

The Ar2(5 p,3Σ(Formula presented.)) and Ar2(5 p,3Πg) states were investigated by inducing transitions from the Ar2(4 s,3Σ(Formula presented.)) state using a dye laser. Ar2 was prepared by exciting argon gas with an electron beam. Absorption measurements with a resolution of better than 0.5 cm−1 were achieved by performing the experiments at pressures down to 0.1 bar. The partially resolved rotational structure gives strong evidence for the description of the molecular levels by Hund's coupling case a or b. A system I consisting of 11 bands were assigned as transitions to the Ar2(5 p,3Σg) state, while a system II composed of transitions to 3 sublevels are due to the Ar2(5 p,3Πg) state. Further absorptions were attributed to transitions to the1Σg and the1Πg states. The assignments are in contrast to the results of previous investigations. © 1990, Springer-Verlag. All rights reserved.