Scattering of 14.1 MeV neutrons by 10 B

The angular distributions of the differential cross-sections for scattering of 14.1 MeV neutrons to the Q = 0, – 1.74, – 2.15, – 3.58, – 4.77, – (5.11 + 5.16 + 5.18), – (5.92 + 6.04 + 6.13), – 6.56 and – (6.88 + 7.0) MeV levels of 10B have been measured for 11° ≤ θCM ≤ 164°. They were deduced from the time-of-flight spectra of neutrons scattered by two targets of different 10B and 11B isotopic concentrations, with the help of a Monte-Carlo program which reproduced the measured spectra. Owing to the small values of the measured cross-sections, a precise determination of parasitic events was necessary. The elastic scattering has been analysed by the optical model. A coherent description of the inelastic scattering to the 2.15, 3.58, 5.16 and 6.56 MeV levels has been achieved with the collective DWBA model. The not yet well-defined parity of the Q = – 6.56 MeV level appears to be negative.