High-energy p-Li neutron field for activation experiment

A p-7Li quasi-monoenergetic neutron field for activation experiment has been developed at energies between 18 and 38 MeV. The absolute neutron intensity was accurately determined from the number of 7Be nuclei produced in the 7Li target which is equal to the number of the monoenergetic peak neutrons released in the 4π direction. The angular distribution function of the peak neutrons is necessary for the estimation of the monoenergetic neutrons emitted in the forward direction for the sample irradiation. The distribution function was measured for proton energies of 20, 30 and 40 MeV and was collected from papers for energies between 25 and 800 MeV to get the universal curve. Activation experiments of various natural and enriched samples were performed at this quasi-monoenergetic neutron field. Here we show the neutron activation cross sections of the 197Au(n, 2n)196Au, 197Au(n, 4n)194Au and 59Co(n, 2nα)54Mn reactions as examples.