Impact of Fission Neutron Energies on Reactor Antineutrino Spectra

Understand

Recent measurements of reactor-produced antineutrino fluxes and energy spectra are inconsistent with models based on measured thermal fission beta spectra.

• In this paper, we examine the dependence of antineutrino production on fission neutron energy.
• In particular, the variation of fission product yields with neutron energy has been considered as a possible source of the discrepancies between antineutrino observations and models.
• In simulations of low-enriched and highly-enriched reactor core designs, we find a substantial fraction of fissions (from 5% to more than 40%) are caused by non-thermal neutrons.