Nuclear Data Needs for Antineutrino Spectra and their Applications
A workshop on the status of reactor antineutrino flux and spectrum measurements—and their comparison with model predictions—will be held at IFIC (CSIC-University of Valencia) from 4 to 8 May 2026.
While significant experimental and theoretical progress has been achieved over the past two decades, the foundations of reactor antineutrino flux models still rely on the integrated beta-spectrum measurements performed by Schreckenbach et al. at ILL in the late 1980s. More recent measurements of the 235U/239Pu beta-spectrum ratio by Kopeikin et al. at the Kurchatov Institute have revealed discrepancies of approximately 5%, suggesting potential normalization issues in the original ILL data.
Furthermore, the first high-precision measurements from JUNO offer exceptional potential to improve our understanding of long-standing questions—such as the Reactor Antineutrino Anomaly (RAA) and observed spectral distortions—while providing deeper insight into the underlying nuclear physics effects.
The workshop will focus on the following primary topics:
- Discussion of the possibility of a new measurement of aggregate beta-energy spectra for the main actinides, enabling a direct comparison with the ILL reference measurements
- Latest results from the recent JUNO measurements
- Advances in decay data from recent TAGS and beta-spectrum experiments
- Impact of the JEFF-4.0 fission-yield evaluation, including associated uncertainties and covariances
The scientific programme will include presentations followed by roundtable discussions allowing ample time for scientific exchange.
The workshop is organized in collaboration with the International Atomic Energy Agency (IAEA) and it is supported by the following institutions and grants including CEX2023-001292-S.
