ROTATIONAL EFFECTS IN THE CONTINUOUS VACUUM-ULTRAVIOLET FLUORESCENCE-SPECTRUM OF H-2 ASSOCIATED WITH SPONTANEOUS DISSOCIATION

The effects of rotational-vibrational interaction, and of rotational coupling between the B 2p u+1 and C 2p u1 electronic states, on the B X fluorescence continuum of H2 associated with spontaneous dissociation were investigated spectroscopically using monochromatized synchrotron radiation for selective excitation of rovibronic states. The rotational shifts and perturbations in the modulated continua intensities observed agree well with close-coupling and Jeffreys-Wentzel-Kromers-Brillouin (JWKB) calculations also performed, and are explained in terms of nonadiabatic coupling effects and rainbow-interference structures. A straightforward experimental technique is described to detect mixed electronic states. © 1990 The American Physical Society.