The two-neutron transfer reactions ( 18O, 16O) with 18O, 14C and 26Mg targets

Abstract

Excitation functions, angular distributions and differential ranges were measured for the 26Mg( 18O, 16O) 28Mg reaction at 18O beam energies of 20–45 MeV. Excitation functions only were measured for the reactions 14C( 18O, 19O) 13C, 14C( 18O, 16O) 16C, 14C( 18O, 20O) 12C, 14C( 18O, 15N) 17N and 18O( 18O, 19O) 17O, 18O( 18O, 16O) 20O, 18O( 18O, 15N) 21F at 18O beam energies of 13–41 MeV. We have identified these as direct reactions in which a single neutron, a two-neutron cluster, a deuteron and a triton are transferred between projectile and target. The cross sections for two-neutron transfer reactions were found to be relatively high and those for the 18O+ 18O and the 14C+ 18O reactions were higher than the ones of single-neutron transfers over most of the energy range. Attempts were made to apply the theory of Buttle and Goldfarb for single-neutron transfer to the case of two-neutron transfer in the 26Mg( 18O, 16O) 28Mg reaction below the Coulomb barrier. It is shown that for those reactions for which the assumptions, implicit in the model, are valid, good agreement is obtained with experiment. We also tried to apply the diffraction model of Dar and Kozlovsky to the calculation of the angular distribution of these reactions. A good fit to the experimental results could be obtained if quite different sets of parameters were used in the calculations for the two bombarding energies.