Neutron capture and the antineutrino yield from nuclear reactors

Abstract

We identify a new, flux-dependent correction to the antineutrino spectrum as produced in nuclear reactors. The abundance of certain nuclides, whose decay chains produce antineutrinos above the threshold for inverse beta decay, has a nonlinear dependence on the neutron flux, unlike the vast majority of antineutrino producing nuclides, whose decay rate is directly related to the fission rate. We have identified four of these so-called nonlinear nuclides and determined that they result in an antineutrino excess at low-energies below 3.2MeV, dependent on the reactor thermal neutron flux. We develop an analytic model for the size of the correction and compare it to the results of detailed reactor simulations for various real existing reactors, spanning 3 orders of magnitude in neutron flux. In a typical pressurized water reactor the resulting correction can reach 0.9% of the low energy flux which is comparable in size to other, known low-energy corrections from spent nuclear fuel and the non-equilibrium correction. For naval reactors the nonlinear correction may reach the 10% level.

5 pages, 2 figures, 2 tables

References in corpus (9)

• Observation of electron-antineutrino disappearance at Daya Bay
• Improved Predictions of Reactor Antineutrino Spectra
• On the determination of anti-neutrino spectra from nuclear reactors
• Experimental Determination of the Antineutrino Spectrum of the Fission Products of ${}^{238}$U
• Antineutrino monitoring for the Iranian heavy water reactor
• Potential of Geo-neutrino Measurements at JUNO
• On Search for New Physics in Nonequilibrium Reactor Antineutrino Energy Spectrum
• Investigation of Neutrino Properties in Experiments at Nuclear Reactors: Present Status and Prospects
• Neutrino Geophysics at Baksan I: Possible Detection of Georeactor Antineutrinos

Cited by in corpus (16)

• Updated global analysis of neutrino oscillations in the presence of eV-scale sterile neutrinos
• Neutrino masses and mixings: Status of known and unknown $3\nu$ parameters
• Sterile Neutrinos
• Improved Measurement of the Reactor Antineutrino Flux and Spectrum at Daya Bay
• Neutrino Detectors as Tools for Nuclear Security
• Extraction of the ${}^{235}$U and ${}^{239}$Pu Antineutrino Spectra at Daya Bay
• Estimation of M1 scissors mode strength for deformed nuclei in the medium to heavy mass region by statistical Hauser-Feshbach model calculations
• Beta-decay studies for applied and basic nuclear physics
• Cosmological constraints with self-interacting sterile neutrinos
• First antineutrino energy spectrum from ${}^{235}$U fissions with the STEREO detector at ILL
• Improving Fission-product Decay Data for Reactor Applications: Part I -- Decay Heat
• Study of the $\beta$-decay of ${}^{100}$Tc with Total Absorption $\gamma$-Ray Spectroscopy
• Improved Measurement of the Evolution of the Reactor Antineutrino Flux and Spectrum at Daya Bay
• Nonfuel Antineutrino Contributions in the High Flux Isotope Reactor
• Cerium ruthenium low-energy antineutrino measurements for safeguarding military naval reactors
• Developing diagnostic tools for low-burnup reactor samples