论文标题
低级伽马光谱法中的密集样品屏蔽背景
Background Shielding by Dense Samples in Low-Level Gamma Spectrometry
论文作者
论文摘要
在低活性的大型样品的伽马光谱测量中，大量样品材料屏蔽了HPGE晶体免受外部背景源的影响。如果在利用背景提取方法的研究中未考虑，则此效果可能会导致样本活动和检测极限估计中的系统错误。我们引入了一种基于蒙特卡洛的方法，以最大程度地减少这种影响对样品伽马光谱的影响。使用模拟检测器背景对其进行验证，并应用于低活动性GD $ _2 $（SO $ _4 $）$ _ 3 \ CDOT $ 8H $ _2 $ o的测量。正确应用该方法的主要先决条件是事先知道有助于检测器背景频谱及其空间分布的核素。通过透彻了解探测器的背景，该方法提高了低活动性样品的敏感低背景测量的准确性。即使在不了解背景来源及其分布的情况下，仍然可以提出保守的结果，以说明这种背景屏蔽效应引入的潜在系统错误。
In low activity gamma spectrometric measurements of large, dense samples, the bulk sample material shields the HPGe crystal from external background sources. If not accounted for in studies that utilise background-subtraction methods, this effect may result in systematic errors in the sample activity and detection limit estimation. We introduce a Monte Carlo based method to minimise the impact of this effect on sample gamma spectra. It is validated using simulated detector backgrounds and applied to a measurement of low-activity Gd$_2$(SO$_4$)$_3 \cdot$8H$_2$O. One main prerequisite for the correct application of this method is to know in advance the nuclides which contribute to the detector background spectrum and their spatial distribution. With a thorough understanding of the detector backgrounds, the method improves the accuracy of sensitive low-background measurements of low-activity samples. Even without knowing the background sources and their distribution, conservative results may still be presented that account for the potential systematic errors introduced by this background shielding effect.
