The double Auger process: energy and angular distribution

Theoretical investigations of the double Auger process, an inner-shell vacancy decays with the emitting of two electrons simultaneously have been made. The lowest nonrelativistic wave functions have been used in the determination of amplitudes, probabilities and angular distribution. The relation between the shake-off' model and authors' calculations is also studied. The simple double Auger transition in Ne have been chosen for a concrete investigation - 1s-1 → 2s-2 2p-1 + 2e. The results are: 1. The energy distribution has a characteristic U-like form similar to the double photoionization one. Therefore the most probable case realized is the case of one fast and one slow electrons. In this situation the 'shake-off' model is valid enough. 1. The transition probability equals about 0.6 x 10-2 eV which is in a good agreement with the experiment. 3. The shape of the angular distribution essentially depends on the energy distribution. the large anisotropy takes place in the case of nearly energies of Auger electrons while the 'shake-off' model predicts the qualitatively different behaviour of the angular distribution. 2 refs. (author)