IODP Expedition 399 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.本数据集包含约0.1至3.0兆电子伏特（MeV）范围的天然γ辐射（Natural Gamma Radiation, NGR）数据，采用8台定制设计的碘化钠（铊）[NaI(Tl)]探测器沿岩心测量轴以20厘米间隔排布进行测量。该天然γ辐射系统搭载多层被动屏蔽（铅）与主动屏蔽（塑料闪烁体及符合电子学电路），可抑制宇宙射线信号，实现沉积物岩心段的低计数分析，并获得最高信噪比。本数据集以每秒总计数为单位报告数据，原始光谱文件以压缩格式存储，可供后续分析使用。