10,11B(n,xγ) REACTIONS FOR INCIDENT NEUTRON ENERGIES BETWEEN 0.1 AND 25 MeV


J.K. Dickens and D.C. Larson

Oak Ridge National Laboratory
P.O. Box 2008
Oak Ridge, TN 37831-6356 USA


Measurements have been made of gamma-ray production due to neutron interactions with samples of boron for incident neutron energies between 0.1 and 25 MeV. For 11B a 54-g sample of naturally-occurring boron in the shape of a solid cylinder was used. For 10B, samples enriched to 95% in the 10B isotope were used. One sample, about 49 g, was used to obtain γ-ray data following inelastic scattering; the other sample, of about 15 g, was used to delineate the production of the 478-keV gamma ray following the 10B(n,αγ)7Li reaction for En between 0.1 and 4 MeV. The Oak Ridge Electron Linear Accelerator (ORELA), a white source, was used to provide the incident neutrons. Data were obtained using a high-purity intrinsic-germanium photon detector positioned at 125 deg with respect to the incident neutron beam. Because the peak shapes in the raw data were substantially broadened by Doppler motion, peak yields were determined with graphic-interactive methods. Except for the 478-keV gamma ray for En < 1 MeV, the γ-ray production cross sections are all small, the largest being < 200 mb.

KEYWORDS: Boron, 10B, 11B, neutron-induced reactions, gamma-ray production