Antineutrino Flux from a Reactor

The antineutrino flux distribution from a thermal neutron reactor is determined from a measurement of the equilibrium beta-ray spectrum from thermal neutron fission of U²³⁵. The antineutrino distribution is then folded in with the cross sections for ̃ \~ν(p, n)β⁺ and ̃ \~ν(d, 2n)β⁺ as a function of antineutrino energy. This determines the average antineutrino pile cross sections σₚ and σd, respectively, for the above-cited reactions. The results are: σₚ=6×10^-44 cm²; σd=2×10^-45 cm².