Femtosecond dissociation of ozone studied by the Auger Doppler effect

Abstract

A Doppler-type shift in the kinetic energy of atomic Auger electrons emitted after fast dissociation of O3 molecules is observed. The resonant Auger spectrum from the decay of repulsive core-excited states reflects both the early molecular ozone decay and that from excited dissociation fragments. The kinetic energy of the fragment is manifested as an energy shift of the atomic Auger lines when the measurement is made under certain conditions. We report measurements of the energy-split atomic fragment emission lines arising from dissociation on a time scale comparable to the core-hole lifetime. For the O 1s–σ* states the kinetic energy release amounts to several electron volts. We report measurements for excitation of both the terminal and central oxygen 1s electrons. A simple kinematic model for extracting a lower limit for the kinetic-energy release is presented and is compared with the result of a Born–Haber cycle, which may be seen as an estimate of the maximum energy release.