ABSTRACT Monitoring only neutron flux in a nuclear reactor core has an advantage of offering reactor power monitoring accuracy. We started the development of a new nuclear instrumentation based on the measurement of prompt gamma rays emitted from metals placed at the neutron flux monitoring positions. The thermal neutron flux at the position of each placed metal piece can be monitored by measuring the prompt gamma rays as the count rate of each energy. The gamma-ray energy range was limited from 6 to 10 MeV to mitigate the interference of environmental gamma rays. Four metals, Ti, V, Ni, and Cu, were chosen as candidates in consideration of their neutron emission rates and self-absorption. In an experiment with a high-purity germanium semiconductor detector, we considered the identification of individual peak energies in an assumed situation where prompt gamma rays were emitted from the four different metals at the same time. Energy resolutions of the peak with the largest energy gap from the nearest energy peak of the other candidate metals were smaller than the gap. Thus, we confirmed that at least one peak for each candidate metal was able to be separated from the peaks derived from other candidate metals.

中文翻译：

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中子诱发瞬发伽马射线核电监测系统的基本考虑

摘要 仅监测核反应堆堆芯中的中子通量具有提供反应堆功率监测精度的优势。我们开始开发一种新的核仪器，其基础是测量放置在中子通量监测位置的金属发出的瞬发伽马射线。通过测量瞬发伽马射线作为每种能量的计数率，可以监测每个放置金属片位置处的热中子通量。伽马射线能量范围被限制在 6 到 10 MeV 之间，以减轻环境伽马射线的干扰。考虑到中子发射率和自吸收，四种金属 Ti、V、Ni 和 Cu 被选为候选金属。在高纯锗半导体探测器的实验中，我们考虑了在四种不同金属同时发射瞬发伽马射线的假设情况下识别单个峰值能量。与其他候选金属的最近能量峰之间具有最大能隙的峰的能量分辨率小于该能隙。因此，我们确认每种候选金属的至少一个峰能够与来自其他候选金属的峰分开。