Measurement of Cross Sections for the 10B(n,α)7Li Reaction at 4.0 and 5.0 MeV Using an Asymmetrical Twin Gridded Ionization Chamber

Cross sections of the 10B(n, α)7Li reaction (including the total, the 'leaking' alpha, forward alpha and backward alpha parts) at En = 4.0 and 5.0 MeV were measured using an asymmetrical twin gridded ionization chamber and two back-to-back 10B samples. Measurements were performed at the 4.5 MV Van de Graaff accelerator of Peking University. Monoenergetic neutrons were produced through the 2H(d, n)3 He reaction with a deuterium gas target. Absolute neutron flux was determined by a 238U sample set inside the gridded ionization chamber and a BF3 long counter was employed as a neutron flux monitor and for normalization. The present results are compared with previous measurements and evaluations. (nuclear physics)