Final Report Summary - COLLEXCIT (Collective excitation in the ionization of atoms, in semiconductors and biological tissues)
Except for closed shells, most atomic states exhibit some collective behavior. That is, the states cannot be described as a single product function, but superpositions of product states. In the description of the interaction of radiations with atoms, the independent particle approximation is used. Our angular distribution and angular correlation study, and in synchrotron photoionisation measurements there is a strong deviation from this model. Revisiting previous measurements with an open eye for the possibility of collective excitations, we can explain the majority of discrepancies by it. We have presented all the evidences in a paper and recommended best practices. We also give a critical review calling attention to the problem that theory laden experiments are used to verify theory. We have made on overview of the problems in determining the L shell fluorescence yields and Coster-Kronig transition probabilities. We have made a critical analysis of the experimental methods which are used to determine Coster-Kronig and fluorescence yield data. We have concluded that each of them has unrecognised systematic errors. We have recommended new approaches.