Angular and energy distributions of electrons ejected in ion-atom collisions

The doubly differential cross sections for the ionisation of the 1s, 2s, 2p 0 and 2p 1 atomic subshells by fast nuclei or atoms are calculated in the first Born approximation with the hydrogen-like wavefunctions. If ionisation has been caused by the atoms, the calculations are fulfilled assuming closure. The spectra of electrons ejected from a fast incident ion are obtained both in the frame of reference moving with the ion and in the laboratory coordinate system.