Double-Differential Neutron-Emission Cross Sections for ⁷Li and Incident Neutrons Between 1.6 and 13.8 MeV

Double-differential neutron-emission cross sections for the ⁷Li(n,xn) reaction are presented for average emission angles of 24, 40, 60, 90, 120, and 150 deg. The incident neutron energy covers the range from 1.6 to 13.8 MeV. The cross sections were measured using an electron linear accelerator as a pulsed white neutron source. Elastically scattered neutrons and neutrons scattered via the 0.48-MeV state are treated as one single group. Inelastic scattering cross sections are obtained for the 4.63- and 6.54-MeV states. For this purpose, the underlying neutron continuum coming from competing tritium-producing reactions (three-particle breakup and sequential two-step reaction via the ⁵He ground state) is estimated using simple physical model calculations. The data are compared with recent evaluations.