Direct and compound nuclear contributions to the 13C( 6Li, t) reaction at Elab = 25 MeV

Abstract

The reaction 13C( 6Li, t) 16O has been studied in the incident energy range 24–26 MeV. Complete angular distributions have been measured at E 6Li , = 25 MeV in the angular range θ lab = 8°–172°, with the reaction 6Li( 13C, t) 6O being used for the backward angle measurements. Cross sections for evaporation residues from the fusion of the 6Li + 13C system have been measured in the incident 6Li energy range 9.2–35.1 MeV. Compound nuclear contributions to the transfer cross sections have been calculated using the Hauser-Feshbach statistical theory with the assumption that the compound-nucleus formation cross section is equal to the measured fusion cross section. By comparison of the compound nuclear calculations with backward angle data it is found that the sharp cutoff approximation commonly used to represent the initial angular momentum distribution of the compound nucleus is not adequate for the 13C( 6Li, t) 16O reaction. Good fits to the backward angle data can be obtained by using a smooth cutoff approximation. The forward angle cross sections have been compared with exact finite-range distorted-wave Born approximation calculations to extract transferred angular momenta and spectroscopic strengths. The present results differ from those of an earlier study. These differences are due to the inclusion of forward angle data in the present study.