136 Xe is used as the target medium for many experiments searching for 0 νββ . Despite underground operation, cosmic muons that reach the laboratory can produce spallation neutrons causing activation of detector materials. A potential background that is difficult to veto using muon tagging comes in the form of 137 Xe created by the capture of neutrons on 136 Xe. This isotope decays via beta decay with a half-life of 3.8 min and a Q β of ∼4.16 MeV. This work proposes and explores the concept of adding a small percentage of 3 He to xenon as a means to capture thermal neutrons and reduce the number of activations in the detector volume. When using this technique we find the contamination from 137 Xe activation can be reduced to negligible levels in tonne and multi-tonne scale high pressure gas xenon neutrinoless double beta decay experiments running at any depth in an underground laboratory.

中文翻译：

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使用3 He中子俘获技术缓解氙气实验中宇宙性137 Xe的背景

136 Xe被用作许多寻找0νββ的实验的目标介质。尽管是地下作业，但到达实验室的宇宙μ子仍会产生散裂的中子，从而引起探测器材料的活化。使用μon标记难以否决的潜在背景是137 Xe的形式，它是由136 Xe捕获中子产生的。该同位素通过β衰变而衰变，半衰期为3.8分钟，Qβ约为4.16 MeV。这项工作提出并探索了在氙气中添加少量3 He的概念，以捕获热中子并减少探测器体积中的激活次数。