Investigation of three-particle effects in autoionisation spectra of electrons by the coincidence method

The authors studied the possibilities of the coincidence method for investigation of the influence of the Coulomb interaction in the final state on electron emission spectra in the vicinity of autoionising resonances. The triple differential cross section, allowing for the Coulomb interaction in the final state in the direct and resonance amplitudes, has been calculated for the ionisation of helium by protons with energies of 100 and 300 keV.