O(D-1) QUANTUM YIELDS OF OZONE PHOTOLYSIS IN THE UV FROM 300 NM TO ITS THRESHOLD AND AT 355 NM

In this paper, we present measurements of O(D-1) quantum yields of ozo ne photolysis, phi(lambda), in the wavelength region between 300 and 3 30 nm and at 355 nm. The data are obtained from an experiment which is based on the reaction of O(D-1) atoms with water and the subsequent d etection of the generated OH by laser-induced fluorescence (LIF). Due to the performance of this method, providing a high level of accuracy and precision, it was possible to answer the question concerning the w avelength dependence of the O(D-1) quantum yield in the threshold regi on. In particular, the value of phi(lambda) at 302.5 nm was determined to be unity, the existence of a saddle point at 315 nm was verified, and the wavelength of the threshold was determined to be between 331 a nd 333 nm. In addition, measurements performed at 355 nm have shown a negligible contribution to the O(D-1) quantum yield. Thus, it can be d educed that a participation of the spin-forbidden process with the pro ducts O(D-1) and O-2((3) Sigma(g)(-)) is unlikely.