title: Spectral structure of electron antineutrinos from nuclear reactors.
abstract: Recent measurements of the positron energy spectrum obtained from inverse beta decay interactions of reactor electron antineutrinos show an excess in the 4 to 6 MeV region relative to current predictions. First-principles calculations of fission and beta decay processes within a typical pressurized water reactor core identify prominent fission daughter isotopes as a possible origin for this excess. These calculations also predict percent-level substructures in the antineutrino spectrum due to Coulomb effects in beta decay. Precise measurement of these substructures can elucidate the nuclear processes occurring within reactors. These substructures can be a systematic issue for measurements utilizing the detailed spectral shape.
authors.affiliation: Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Dwyer
authors.affiliation: Yale University, New Haven, Connecticut 06520, USA.
authors.forename: T J
authors.initials: TJ
authors.lastname: Langford