IODP Expedition 339 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0.1~3.0 MeV能段的天然伽马辐射（Natural gamma radiation, NGR）数据。数据采集采用八台定制设计的碘化钠（铊）[NaI(Tl)]探测器，沿岩心测量轴以20厘米间距布置。该NGR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电路），可抑制宇宙射线信号，以实现沉积物岩心样品的低计数分析，并获得最优信噪比。数据以每秒总计数为单位上报，原始谱文件以压缩包形式提供，可供后续分析使用。