Title: First Measurement of Neutrino Emissions from Spent Nuclear Fuel by the Double Chooz Experiment Show Chinese title

Title: 第一测量由双丘兹实验从用过的核燃料中中微子发射

Abstract: Neutrino emission from nuclear reactors provides real-time insights into reactor power and fuel evolution, with potential applications in monitoring and nuclear safeguards. Following reactor shutdown, a low-intensity flux of ``residual neutrinos'' persists due to the decay of long-lived fission isotopes in the partially burnt fuel remaining within the reactor cores and in spent nuclear fuel stored in nearby cooling pools. The Double Chooz experiment at the Chooz B nuclear power plant in France achieved the first quantitative measurement of this residual flux based on 17.2 days of reactor-off data. In the energy range where the residual signal is most pronounced, the neutrino detector located 400$\,$m from the cores recorded $106 \pm 18$ neutrino candidate events (5.9$\sigma$ significance). This measurement is in excellent agreement with the predicted value of $88 \pm 7$ events derived from detailed reactor simulations modeling the decay activities of fission products and incorporating the best-available models of neutrino spectra. Show Chinese abstract

Abstract: 中微子从核反应堆的发射提供了对反应堆功率和燃料演化的实时洞察，具有在监控和核保障方面的潜在应用。 反应堆关闭后，由于部分燃烧燃料中长寿命裂变同位素的衰变，在反应堆核心内以及附近冷却池中储存的乏核燃料中仍存在低强度的"残余中微子"通量。 在法国查兹B核电站进行的双查兹实验基于17.2天的停堆数据，首次对这种残余通量进行了定量测量。 在残余信号最显著的能量范围内，距离核心400$\,$米处的中微子探测器记录了$106 \pm 18$个中微子候选事件（5.9$\sigma$显著性）。 这一测量与根据详细反应堆模拟得出的预测值$88 \pm 7$个事件高度一致，该模拟考虑了裂变产物的衰变活动，并结合了中微子谱的最佳现有模型。