论文标题
使用单个高纯净锗检测器的100mo富集粉末样品的背景活动的测量
Measurement of the Background Activities of a 100Mo-enriched powder sample for AMoRE crystal material using a single high purity germanium detector
论文作者
论文摘要
先进的基于钼的稀有过程实验（Amore）在富集的molybdate晶体中搜索100MO的无中微子双β（0ν\ b {eta} \ b {eta}）衰减。 Amore晶体必须具有低水平的放射性污染，以实现低背景信号，并在100mo0ν\ b {eta} \ b {eta}衰减的Q值附近的能量附近。为了产生低活动性晶体，必须控制和量化用于形成晶体的原材料中的放射性污染物。富含100MO同位素的100ENRMOO3粉末特别感兴趣，因为它是晶体中100MO的来源。具有100％相对效率的高纯锗检测器（名为CC1）正在扬阳地下实验室运营。使用CC1，我们从1.6千克100ENRMOO3粉末样品中收集了一个富含100mo的96.4％的伽马谱。分析了同位素228AC，228，226RA和40K的活动。它们是长期存在的天然同位素，可以在Amore感兴趣的地区产生背景信号。 228AC和228TH的活动在90％的置信度下<1.0 MBQ/kg（C.L.）。 226RA的活性被测量为5.1 \ pm 0.4（STAT）\ pm 2.2（Syst）MBQ/kg。在90％C.L.时，发现40K活性为<16.4 MBQ/kg。
The Advanced Molybdenum-based Rare process Experiment (AMoRE) searches for neutrino-less double-beta (0ν\b{eta}\b{eta}) decay of 100Mo in enriched molybdate crystals. The AMoRE crystals must have low levels of radioactive contamination to achieve low background signals with energies near the Q-value of the 100Mo 0ν\b{eta}\b{eta} decay. To produce low-activity crystals, radioactive contaminants in the raw materials used to form the crystals must be controlled and quantified. 100EnrMoO3 powder, which is enriched in the 100Mo isotope, is of particular interest as it is the source of 100Mo in the crystals. A high-purity germanium detector having 100% relative efficiency, named CC1, is being operated in the Yangyang underground laboratory. Using CC1, we collected a gamma spectrum from a 1.6-kg 100EnrMoO3 powder sample enriched to 96.4% in 100Mo. Activities were analyzed for the isotopes 228Ac, 228Th, 226Ra, and 40K. They are long-lived naturally occurring isotopes that can produce background signals in the region of interest for AMoRE. Activities of both 228Ac and 228Th were < 1.0 mBq/kg at 90% confidence level (C.L.). The activity of 226Ra was measured to be 5.1 \pm 0.4 (stat) \pm 2.2 (syst) mBq/kg. The 40K activity was found as < 16.4 mBq/kg at 90% C.L.
