Quasielastic transfer reactions induced byFe56onNi58,Ni64, andSn122

Abstract

Differential cross sections sigma(Z,A,E,theta) for the quasielastic projectilelike reaction products from the bombardment of /sup 56/Fe on /sup 58,64/Ni and /sup 122/Sn at 5.9 and 8.5 MeV/nucleon have been measured with a channel-plate time-of-flight telescope followed by a ..delta..E-E gas-ionization chamber. Angular intervals of 10/sup 0/--15/sup 0/ centered at the grazing angles were covered. The differential cross sections for one-proton transfer with Q values near zero were analyzed using the distorted-wave Born approximation, which can account for the shape of the angular distributions and, to better than a factor of 5, for the absolute cross sections. At Q values more negative than -10 MeV the measured angular distributions begin to deviate from the distorted-wave Born approximation predictions. Substructures were observed in the energy spectra near Q = -25 MeV. A model for unfolding the effects of particle evaporation from the reaction products is developed. It is shown that, within the limitations of the model, the observed substructures cannot be accounted for by evaporation effects alone but must be present in the primary energy spectra. Finally the optimum Q values are analyzed with a one-body dissipation model. The model is reasonably successful if the concept of a local Fermi momentum ismore » introduced.« less