Femtosecond dissociation of ozone studied by the Auger Doppler effect

A Doppler-type shift in the kinetic energy of atomic Auger electrons emitte d after fast dissociation of O-3 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. T he kinetic energy of the fragment is manifested as an energy shift of the a tomic Auger lines when the measurement is made under certain conditions. We report measurements of the energy-split atomic fragment emission lines ari sing from dissociation on a time scale comparable to the core-hole lifetime . For the O 1s-sigma* 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 wit h the result of a Born-Haber cycle, which may be seen as an estimate of the maximum energy release. (C) 2001 American Institute of Physics.