Double-electron capture in very-slow C{sup 4+} {r_arrow} He collisions

We have studied double-electron capture in C{sup 4+} {yields} He collisions for projectile energies between 400 eV and 1000 eV. In our experimental setup we can detect the energy gain and the scattering angle of the projectile simultaneously. In the covered energy regime both electrons from the He target are captured into the ground state of C{sup 2+} (1s{sup 2}2s{sup 2}). The angular distributions show an interference pattern that can be attributed to Stueckelberg oscillations. The results presented will be compared to measurements by other authors and to two different theoretical calculations.