A DIRECT MEASUREMENT OF THE O(D-1) QUANTUM YIELDS FROM THE PHOTODISSOCIATION OF OZONE BETWEEN 300 AND 328 NM

The relative quantum yields of O(D-1) produced in the photolysis of oz one at 298 K between 300 and 328 nm have been measured directly by res onance-enhanced multiple photon ionisation of the fragment. Clear indi cations are seen of a tail in the quantum yield extending to the long- wavelength limit of the experiments. Comparisons with previous studies are made to assess the importance of the photolysis of vibrationally excited molecules and spin-forbidden dissociation at wavelengths beyon d the 310 nm thermodynamic threshold for the formation of both atomic and molecular oxygen in their singlet states.