Charge exchange and X-ray emission in 70Â MeV/u Bi-Au collisions

Charge exchange and X-ray emission for 70 MeV/u highly charged ions of Biq+ [77 ⩽ q ⩽ 82] colliding with thin Au targets [21 ⩽ t in μg/cm2 ⩽ 225] were measured at the heavy ion synchrotron SIS at GSI. For the innermost shells this beam energy implies a quasiadiabatic collision regime. The charge state distribution of the emerging ions was measured by a position sensitive CVD-diamond detector after being analyzed by a magnet spectrometer. Charge exchange cross sections have been deduced from the target thickness dependence of the charge state distribution. Electron capture at distant collision dominates completely over ionization at close collision. The X-ray emission from the collision partners were measured by solid state detectors, Ge(i). The K X-ray emission for closed and open incoming projectile K vacancies gives access to vacancy transfer in the superheavy quasi-molecule transiently formed during collision for the innermost shells.