Overview
- The Double Chooz team analyzed 17.2 days of data recorded while both Chooz reactor units were shut down and identified about 100 antineutrino candidate events from the reactor cores and nearby spent‑fuel pools.
- The signal was seen in the experiment’s underground liquid‑scintillator detector roughly 400 metres from the cores and required the detector’s more than 30 cubic metres of scintillator and very low background noise to isolate the faint flux.
- Measured event rates agree closely with detailed simulations of long‑lived fission‑product decay, providing the first direct experimental validation of predicted antineutrino emissions from shutdown reactors.
- Researchers say the result, published in Physical Review Letters, shows antineutrino detectors could offer an independent, non‑intrusive way to confirm reactor status and spent‑fuel inventories during outages and storage.
- The finding repurposes a neutrino‑oscillation experiment and sets a published benchmark that other groups such as JUNO‑TAO can use to refine methods and assess practical safeguards applications.