CO RYDBERG SERIES CONVERGING TO THE CO-STATE AND C-STATE OBSERVED BY VUV-FLUORESCENCE SPECTROSCOPY( D)

The undispersed and dispersed vacuum ultraviolet fluorescence (lambda( F1) = 105-200 nm) after neutral photodissociation excitation of CO has been measured as a function of the exciting-photon energy in the regi on between 18.5 and 36 eV. The target-gas pressure dependence of the f luorescence intensities for energies below 23 eV was observed to be li near. For exciting photon energies above 23 eV photoelectron impact ex citation of neutral CO from the ground to the CO(A (1) Pi) state cause s a nonlinear pressure dependence of the undispersed fluorescence inte nsity. CO Rydberg states converging to the CO+ D and C states have bee n assigned on the basis of the recorded spectra. Previous assignments of the R-C(3s,4s,3p,4p) and R-D(3s,4s) Rydberg series could be support ed and the identification of their vibrational levels have been consid erably extended. Two new progressions (R-D(5s,6s)) have been assigned.