Measurements of double-differential neutron emission cross sections of Li-6, Li-7 and Be-9 for 11.5 MeV and 18.0 MeV neutrons

Double-differential neutron emission cross sections (DDXs) of Li-6, Li-7 an d Be-9 were measured for 18.0 MeV and 11.5 MeV incident neutrons produced b y the T(d, n) and N-15(d, n) reactions respectively, using the Tohoku Unive rsity Dynamitron time-of-flight (TOF) spectrometer. The data were obtained at 13 laboratory angles, and angular-differential cross sections (ADXs) of elastic and inelastic scattering neutrons were derived from the DDXs. For 1 1.5 MeV neutrons, we obtained the neutron emission spectra over the seconda ry neutron energies by newly employing the double TOF method as well as the conventional one. In the measurements at 18.0 MeV, we achieved better ener gy resolution than in our previous studies by using a neutron detector that has a larger solid angle and a thinner tritium target. The experimental re sults of DDXs and ADXs were compared with our previous results and the eval uated data given in JENDL-3.2, JENDL Fusion File and ENDF/B-VI. It is found that the JENDL data reproduce the experimental ones very well.