Polarizational bremsstrahlung of atomic particles in the relativistic and ultra-relativistic regimes

The features of polarizational bremsstrahlung emitted in an elastic collision of a charged particle with a many-electron target are studied for the relativistic and ultra-relativistic collision regimes. The numerical data on the cross sections and angular distributions of polarizational bremsstrahlung are presented. It is demonstrated that the polarizational bremsstrahlung cross section increases logarithmically with the energy of incident particle. The relativistic effects were shown to result in substantial asymmetry of the angular distribution of emitted photons.