Pt L X-RAYS PRODUCTION CROSS SECTIONS BY C-12, O-16, S-32 AND Ti-48 ION-BEAMS IN THE MeV/u ENERGY RANGE

By using 0.5-4 MeV/u C-12 and O-16, and 0.25-2.5 MeV/u S-32 and Ti-48 ion beams, delivered by the 9 MV tandem accelerator of IFIN-HH, Pt L X-ray production cross sections have been determined. The comparison with model predictions for direct ionization (SCA and ECPSSR) has put in evidence the dominance of the ionization from atomic states in the case of C-12, O-16 + Pt collisions, and the molecular orbital (MO) mechanisms in the case of Ti-48 + Pt collision. A possible contribution of MO mechanisms to the target L-shell ionization in the collision system S-32 + Pt is discussed. The effect of vacancy sharing between the L-subshells, included in the first order in the calculations, is small for the total X-ray yields reported here. Possible solid-state effects on the X-ray transitions involving outer-shell electrons are noted.