Neutron Transfer inN14(N14,N13)N15at Low Energies

Abstract

Formulas concerned with approximate quantum-mechanical corrections to the semiclassical (SC) treatment of the neutron transfer reaction previously contained or implied in the literature are extended and put in a more convenient form for application. New data of McIntyre, Jobes, and Becker in the laboratory energy range 9.0 to 18.0 MeV are compared with theoretical expectation. The accuracy of a previous discussion of 18-MeV data by one of the authors is improved. At 18 and at 12.6 MeV reasonable agreement with experimental angular distributions is found close to 90° in the c.m. system. At smaller angles the experimental values of the cross section are below those calculated at 18 MeV, in agreement with the influence of absorption on the recoils suggested for this case by McIntyre and Jobes; at 12.3 MeV the experimental values are somewhat smaller than the theoretical as would be the case in the presence of virtual Coulomb excitation (VCE). Total transfer cross sections show a systematic increase over expectation by a factor of about 2.9 between 9.0 and 12.8 MeV as though some VCE were present. The calculated ratio of the 90° cross section at 18 MeV to that at 12.6 MeV is about 10 times that observed. Possible explanations of this discrepancy are discussed.