The 9Be(n,p)9Li reaction and the Gamow–Teller unit cross section Original Research Article

Double differential cross sections of the 9Be(n,p)9Li reaction have been measured at 96 MeV in the angular range 0°−27° up to about 20 MeV excitation energy. In addition, the 12C(n,p)12B reaction has been measured in the same angular and excitation energy range. Cross sections for reactions leading to the ground state and the first excited state (2.69 MeV) of 9Li have been analysed using peak-fitting techniques. The data have been compared with cross sections obtained from distorted-wave Born approximation calculations. A Gamow–Teller (GT) unit cross section for the ground state transition of 7.4±1.2 mb/sr was determined from the identified GT strength. Discrepancies in the Gamow–Teller unit cross sections for different (n,p) and (p,n) transitions from the 9Be ground state, resembling the situation for 13C, have been found.