论文标题
Legend-200实验的校准源
Calibration sources for the LEGEND-200 experiment
论文作者
论文摘要
在寻找单色峰作为中性元β衰减的签名时，衰减的$ q $ - 价值围绕$ q $ - value的超低背景至关重要。 Legend-200实验进行了这样的搜索，其中含有$^{76} $ ge浓缩的高纯净锗探测器浸入了液体氩气中。为了确定和监视锗二极管的稳定性和分辨率，定制，低中子发射$^{228} $ TH来源定期在晶体附近部署。在这里，我们描述了可在实验中安装的17个来源的生产过程，其α和γ-活性的测量值以及通过低背景LII（EU）检测器在深层地下运行的中子排放速率的确定。 $ \左（4.27 \ pm 0.60 _ {\ rm stat} \ pm 0.92 _ {\ rm syst} \ right）\ times 10^{ - 4}〜\ text { $^{76} $ ge，与传奇-200中的其他背景来源相比，$ ge可以忽略不计。
In the search for a monochromatic peak as the signature of neutrinoless double beta decay an excellent energy resolution and an ultra-low background around the $Q$-value of the decay are essential. The LEGEND-200 experiment performs such a search with high-purity germanium detectors enriched in $^{76}$Ge immersed in liquid argon. To determine and monitor the stability of the energy scale and resolution of the germanium diodes, custom-made, low-neutron emission $^{228}$Th sources are regularly deployed in the vicinity of the crystals. Here we describe the production process of the 17 sources available for installation in the experiment, the measurements of their alpha- and gamma-activities, as well as the determination of the neutron emission rates with a low-background LiI(Eu) detector operated deep underground. With a flux of $\left( 4.27 \pm 0.60_{\rm stat} \pm 0.92_{\rm syst} \right) \times 10^{-4} ~\text{n / (kBq$\cdot$s)}$, approximately one order of magnitude below that of commercial sources, the neutron-induced background rate, mainly from the activation of $^{76}$Ge, is negligible compared to other background sources in LEGEND-200.
