Charge exchange in collisions of 1-100-keV Sn3+ ions with H-2 and D-2

Absolute cross sections for single electron capture by Sn3+ colliding with H-2 and D-2 have been measured and calculated in the energy range of 1-100 keV. The cross sections are determined by measuring the change in ion beam current with varying target density and by measuring the yields of charged target fragments by means of a time-of-flight spectrometer. The results for D-2 show good agreement with our seven-state semiclassical calculations, while for H-2 the experimental results increase more strongly than the calculations toward lower energies. This discrepancy is attributed to vibrational effects, not included in the calculations, that lead to the breakdown of the Franck-Condon approximation.