β Decay Spectra Measurements for the Study of Reactors’ Antineutrino Spectra

¹ Instituto de Física Corpuscular (IFIC), València, Spain
² Institute for Nuclear Research (Atomki), Debrecen, Hungary
³ SUBATECH, CNRS/IN2P3, IMT Atlantique, Nantes Université, Nantes, France
⁴ Faculty of Physics, University of Warsaw, Warsaw, Poland
⁵ Department of Physics, University of Surrey, Guildford, United Kingdom
⁶ Department of Physics, University of Jyväskylä, Jyväskylä, Finland
⁷ LPC Caen, CNRS/IN2P3, Caen, France

^* e-mail: galcala@ific.uv.es
^** Current address: Faculty of Physics, University of Warsaw, 02-093 Warsaw, Poland

Published online: 11 April 2025

Abstract

Updated reactor antineutrino spectra predictions, based on the Huber-Muller Conversion model, revealed discrepancies known as the Reactor Antineutrino Anomaly (RAA) and the spectral “bump”, raising concerns about the accuracy of the models and data used for these predictions. Consequently, improved nuclear data measurements are essential. The Summation method, an alternative to the Conversion model, may offer more accurate reactor antineutrino spectra predictions. Since a relative small number of fission products significantly contribute to antineutrino spectra in a region where the “bump” is prominent, precise measurements of β^- spectra are crucial. This report presents preliminary steps needed for the analysis of the ⁹²Rb β^- spectrum measured at IGISOL, such as the Monte Carlo model validation.