By applying the deceleration technique for bare uranium ions at the ESR sto
rage ring we studied the Radiative Electron Capture process in collisions w
ith low-Z target atoms. This allowed us to extend the current information a
bout the time-reversed photoionization process of highly-charged heavy ions
to much lower energies than those accessible for neutral heavy elements in
the direct reaction channel. The angular differential data obtained prove
theoretical predictions that at high-Z higher-order multipole contributions
and magnetic corrections play an important role even at energies close to
the threshold.