The role of 14 MeV neutrons in light element nucleosynthesis

The 14 MeV neutron induced nuclear reactions which might contribute to better understanding of so-called “cosmological lithium problem” have been discussed. The BBN theory predicted 7Li overestimated value could be lowered by 2n induced reactions on Li-isotopes and/or 7Be destruction via resonance in d+7Be→9B process.

Proposals for 6Li+2n and 7Li+2n reactions cross section evaluations and measurements are discussed in some details.

We discuss also a preliminary measurements of n-n coincidences from the 10B(n,2n)9B reaction with two neutron detectors placed outside the cone of 14 MeV tagged neutron beam. From the time-of-flight measurements and known geometry we deduce the neutron energies and calculate the 9B missing mass spectrum.