IODP Expedition 391 Natural gamma radiation

Natural gamma radiation (NGR) data in the ~0.1 to 3.0 MeV range were measured using eight custom-designed sodium iodide (thallium) [NaI(Tl)] detectors arranged along the core measurement axis at 20 cm intervals. The NGR system uses layers of passive shielding (lead) and active shielding (plastic scintillators and coincidence electronics) to reduce the cosmic-ray signal for low-count analysis of sediment core sections and to obtain the maximum signal-to-noise ratio. Data are reported on a total counts per second basis and the raw spectral files are available as compressed files for later analysis.本数据集涵盖约0.1至3.0兆电子伏特（MeV）能段的天然伽马辐射（Natural gamma radiation, NGR）实测数据。本次测量采用8台定制的碘化钠（铊）[NaI(Tl)]探测器，沿岩心测量轴以20厘米的间距布置。该天然伽马辐射探测系统配备多层被动屏蔽（铅）与主动屏蔽（塑料闪烁体及符合电子学线路），可有效抑制宇宙射线信号，以实现沉积岩心段的低计数分析，并获得最优信噪比。数据以每秒总计数为单位进行报告，原始光谱文件以压缩格式存储，可供后续分析使用。