STUDY OF ELECTRONICALLY EXCITED-STATES OF OZONE BY ELECTRON-ENERGY-LOSS SPECTROSCOPY

Electronically excited states of ozone have been studied by electron-e nergy-loss spectroscopy. Two broad bands without visible vibrational s tructure are observed at 1.8+/-0.2 eV and 2.05+/-0.05 eV under scatter ing conditions favoring singlet excitation, that is a scattering angle of theta=10 degrees and residual energy E(r)=20 eV. The lower is assi gned as (1)A(2), the higher as B-1(1) (Chappuis band). Bands with rich vibrational structure are observed under scattering conditions favori ng tripler excitation, theta=30 degrees-135 degrees and residual energ y E(r)=1-3 eV. At least two vibrational progressions can be discerned. The first has an origin at 1.30 eV, the origin of the second cannot b e determined unambiguously, it is either at 1.53 or 1.45 eV. The well- known Hartley band and a number of other singlet and triplet excited s tates are observed at higher energy losses. Excitation functions and a ngular distributions of the triplet band at 1.30 eV and of the Hartley band are presented. The absolute value of the differential cross sect ion for excitation of the Hartley band is given. (C) 1996 American Ins titute of Physics.