Gamma-ray spectrometry is a widely used technique to quantify the presence of numerous radionuclides in environmental samples. In this work, we describe a methodology for efficiency calibration of four well-type germanium detectors and their use for the determination of low-level activities of gamma emitters in sediment samples. An experimental efficiency calibration for each detector was built with three materials for 17 energies, ranging from 46.5 keV to 1460 keV. For efficiency transfer to different geometries and sample types, we used the effective solid angle approach (ET-Ω method). Final calibrations were calculated for all detectors, several counting geometries, and elemental composition of selected sample types. Calibrations were validated with six reference materials. This methodology allowed to reliably analyze nine gamma emitters (²¹⁰Pb, ²⁴¹Am, ²³⁴Th, ²²⁸Ac, ²¹⁴Pb, ²⁰⁸Tl, ¹³⁷Cs, ¹³⁴Cs and ⁴⁰K) in sediment samples. Using these calibrations, gamma emitter profiles of sediment cores from contrasting aquatic systems (lake, intertidal, marine and deep-sea areas) provided reliable profiles of ²¹⁰Pb and artificial radionuclides useful for dating and stratigraphic interpretation. A protocol to implement this methodology is also presented.

伽玛射线光谱法是一种广泛使用的技术，用于量化环境样品中大量放射性核素的存在。在这项工作中，我们描述了一种用于四个井型锗探测器效率校准的方法，以及它们用于确定沉积物样品中伽马发射器的低电平活动的方法。每个探测器的实验效率标定是使用三种材料建立的，用于17种能量，范围从46.5 keV到1460 keV。为了将效率转移到不同的几何形状和样品类型，我们使用了有效的立体角方法（ET-Ω方法）。对所有检测器，几种计数几何形状以及所选样品类型的元素组成进行了最终校准。使用六种参考材料对校准进行了验证。这种方法可以可靠地分析9个伽玛发射器（²¹⁰ Pb，²⁴¹ Am，²³⁴ Th，²²⁸ Ac，²¹⁴ Pb，²⁰⁸ Tl，¹³⁷ Cs，¹³⁴ Cs和⁴⁰ K）。使用这些校准，来自对比水生系统（湖泊，潮间带，海洋和深海区域）的沉积物核的伽马发射体剖面提供了可靠的²¹⁰ Pb剖面和人工放射性核素，可用于测年和地层解释。还介绍了实现此方法的协议。