Neutrino Energy Spectra from Nuclear Reactors Calculated from Nuclear Data Libraries

Abstract

Nuclear reactors generate a highly intense flux of electron‐antineutrinos from fission products through β− decay, and produce a slight number of electron‐neutrinos through either β+ decay or electron capture. Neutrino energy spectra are usually calculated by the β decay theory. Since the reactor neutrinos are emitted from a great number of fission products, the calculation requires many level schemes of these nuclides. Nuclear data files, however, are available these days. It is possible to evaluate the electron‐antineutrino and ‐neutrino spectra for a nuclear reactor on the basis of nuclear data files (JENDL‐FP‐Decay‐Data‐File‐2000, JENDL‐3.3).In this study, we derive electron‐neutrino and ‐antineutrino spectra in the energy range of 10 keV to 8 MeV from nuclear data files. The method gives good agreement with other studies for electron‐antineutrino spectra. We show a simple method for estimating the reactor neutrino spectra without complicated computation.