论文标题
HPGE探测器内的脉搏形状歧视和大量事件
Pulse Shape Discrimination of Bulk and Very Bulk Events within HPGe Detectors
论文作者
论文摘要
CDEX（中国暗物质实验）现在部署了约10 kg PPCGE（p型点与CJPL（中国在地下实验室））中的检测器。它旨在检测罕见的事件，例如暗物质和0VBB（中准双β衰减）。散装和非常批量事件的歧视对于改善暗物质的分析阈值至关重要。非常大的事件是在PPCGE的P+点表面附近产生的，PPCGE的P+点表面通常来自电子设备的放射性材料。由于电荷收集的不同位置，散装和散装事件具有不同的脉冲形状。本文将介绍两个线性PSD（脉冲形状歧视）方法：CCM（电荷比较方法）和Fisher的LDA（线性判别分析），以实现对批量和非常批量事件的歧视。结果表明，CCM和Fisher's LDA分别为FOM（功绩图）为1.38 $ \ pm $ 0.33和1.62 $ \ pm $ 0.18。
The CDEX (China Dark matter Experiment) now deploys ~10 kg pPCGe (p-type Point Contact Germanium) detectors in CJPL (China Jinping Underground Laboratory). It aims to detect rare events such as dark matter and 0vbb (neutrinoless double beta decay). The discrimination of bulk and very bulk events are essential for improvements of the analysis threshold of dark matter. Very bulk events are generated near the p+ point surface of pPCGe, which are usually from radioactive materials of electronic devices. Due to different locations of charge collection, bulk and very bulk events have different pulse shape. This paper will present two linear PSD (Pulse Shape Discrimination) methods: CCM (Charge Comparison Method) and Fisher's LDA (Linear Discriminant Analysis), to realize the discrimination of bulk and very bulk events. The results show that FOMs (Figure of Merit) are 1.38 $\pm$ 0.33 and 1.62 $\pm$ 0.18 by CCM and Fisher's LDA respectively.
