Polarization effects in atomic transitions

In this review an attempt is made to provide a unified description of various types of atomic core polarization effects in the free – free, free – bound and bound – bound transitions of charged particles in the field of a multielectron atom — effects that have generally been treated independently in various contexts for over 40 years. For all types of transitions, both classical and quantum models are used for describing the scattering and energy reemission of a particle interacting with the atomic core. Experimental and theoretical results are given for the oscillator strengths of atoms and multiply charged ions; polarization phenomena associated with the photoeffect; a new polarization recombination channel, and the bremsstrahlung of electrons, relativistic and heavy particles on complex atoms and ions.