Fissile isotopes antineutrino spectra: summation method and direct experiment

TL;DR

This paper presents new antineutrino spectra for fissile isotopes using a combined calculation and experimental fitting approach, improving the accuracy of predicted reactor antineutrino signals and matching observed spectral features.

Contribution

It introduces a novel combined method for calculating and fitting antineutrino spectra of fissile isotopes, aligning predictions with experimental data and observed spectral features.

Findings

Calculated cross sections match experimental measurements well

Spectra exhibit the 5 MeV 'bump' observed in experiments

Closest agreement with previous predictions among all models

Abstract

New antineutrino spectra of fissile isotopes ($^{235}$U, $^{238}$U, $^{239}$Pu and $^{241}$Pu) which are containing in a nuclear reactor fuel have been obtained. A combined technique was used: calculation of antineutrino spectra and their fitting to those obtained in the experiment at the Rovno NPP in the 80s of the last century. The cross sections of fissile isotopes calculated with these spectra describe well the cross section obtained experimentally in the Double Chooz experiment. The calculated cross section for the same reactor core composition is $\sigma_{f} = (5.82 \pm 0.12)\times10^{-43}$ cm$^2$/fission. It is the closest result between all predicted. The obtained spectra have the same "bump" as experimental ones in 5 MeV observed energy region.