VUV OPTICAL-ABSORPTION AND ELECTRON-ENERGY-LOSS SPECTROSCOPY OF OZONE

Absolute VUV optical absorption cross sections for ozone have been mea sured between 325 and 110 nm (3.0-11.3 eV) using a synchrotron radiati on source. Vibrational fine structure is resolved in Rydberg bands and comparison of this with the limiting bands in the photoelectron spect rum confirms that the order (increasing ionization energy) of the thre e lowest ionization bands is (2)A(1) < B-2(2) < (2)A(2). Near-threshol d electron energy-loss spectra have also been recorded. In these, in a ddition to the known tripler states between 1 and 2 eV, a low-lying tr ipler state has been located around 3.4 eV and several others between 6 and 9 eV. Characterization of the valence states (both optically all owed and forbidden) are discussed in relation to the results of early theoretical computations which seem to give a good account of the ozon e spectrum.