Oscillatory variation near the C-K edge in the photon W-value of ethylene

The dependence of ethylene W-value on photon energy has been precisely measured in the region from 269 to 324 eV by using monochromatized synchrotron radiation. The W-value showed an oscillatory variation at the C1s → π* excited state as well as the C-K edge. A model has been proposed in which the inner-shell excitation gives rise to a change in the energy of the electron ejected from the molecule having absorbed a photon. It has been found that the model can reproduce the oscillatory variation feature of the W-value. (author)