Radiative electron capture in relativistic atomic collisions

Radiative electron capture (REC) from a low-Z target atom into a bare high-Z projectile is described in the impulse approximation for the momentum distribution of the captured electron in the initial target state. Otherwise the treatment is rigorous by using exact relativistic Coulomb wave functions for the bound and continuum projectile states. As an application of the computer program, photon spectra and differential cross sections have been calculated for 295-MeV/u ${\mathrm{U}}^{92+}$+N collisions. The angular distributions for K-shell REC as well as for L-shell REC show pronounced deviations from ${\mathrm{sin}}^{2}$\ensuremath{\theta}. Cross sections for radiative recombination with capture into the K shell and into the L subshells are presented for projectile charges between 20 and 100 and for energies between 100 MeV/u and 2 GeV/u.