Electron Transfer Processes to Continuum in Near-Relativistic Ion-Atom Collisions

Theories for electron transfer to the continuum have encountered considerable difficulties to take into account the intrinsic many-electron processes in the capture channel. This may partially be attributed to large momentum transfers involved and thus collision systems are mostly not in the realm of first order perturbation theories. For this reason we have studied collision systems where simultaneously distinct competing electron transfer processes are found to be active, like radiative (RECC) and non-radiative electron capture to continuum (ECC) in the relativistic domain where one or two even active electrons are involved; here another, though distinct, transfer process, the projectile electron loss to continuum (ELC), permits additionally to study the dynamics of ionization very close to threshold. We have studied these electron transfer processes simultaneously in forward electron emission in two systems of different projectile Compton profile, U88+ + N-2 and Sn47+ + N-2 collisions using the forward electron spectrometer at the supersonic jet-target of the ESR storage ring. We report first results and compare with theory.