论文标题
Nexo的新型VUV敏感硅光化器的性能
Performance of novel VUV-sensitive Silicon Photo-Multipliers for nEXO
论文作者
论文摘要
液体氙时间投影室有望探测探测器,因为它们的响应均匀性,单片敏感性,对大型目标质量的可扩展性以及对极低背景操作的适用性,因此可以寻找中性s的双β衰减(0 $νββ$)。 Nexo合作设计了一个吨级的时间投影室,旨在搜索0 $νββ$ \ ce {^{^{136} Xe},预计的半寿命敏感性为$ 1.35 \ times 10^{28} $ 〜yr。为了达到这种敏感性,Nexo的设计目标是$ \ leq $ 1 \%的能量分辨率在decay $ q $ - value($ 2458.07 \ pm 0.31 $ 〜kev)。达到该分辨率需要有效收集检测器中产生的电离和闪烁。 Nexo设计采用了硅光化器(SIPM)来检测真空超紫罗兰色,液体Xenon的175 nm闪烁光。本文报告了最新的真空超紫罗兰色敏感的Fondazione Bruno Kessler Vuvhd3 SIPM的表征,专门针对Nexo设计,以及对先前表征的Hamamatsu Vuv4 Multi Multi Pixel Photion Photon ounter(MPPCS)的新测试样品的新测量。各种SIPM和MPPC参数,例如暗噪声,增益,直接串扰,相关的雪崩和光子检测效率,是在液体XENON温度下(163〜K)施加的电压和波长的函数。这项研究的结果用于在Nexo Design的衰减$ Q $值下提供可实现的能量分辨率的更新估计。
Liquid xenon time projection chambers are promising detectors to search for neutrinoless double beta decay (0$νββ$), due to their response uniformity, monolithic sensitive volume, scalability to large target masses, and suitability for extremely low background operations. The nEXO collaboration has designed a tonne-scale time projection chamber that aims to search for 0$νββ$ of \ce{^{136}Xe} with projected half-life sensitivity of $1.35\times 10^{28}$~yr. To reach this sensitivity, the design goal for nEXO is $\leq$1\% energy resolution at the decay $Q$-value ($2458.07\pm 0.31$~keV). Reaching this resolution requires the efficient collection of both the ionization and scintillation produced in the detector. The nEXO design employs Silicon Photo-Multipliers (SiPMs) to detect the vacuum ultra-violet, 175 nm scintillation light of liquid xenon. This paper reports on the characterization of the newest vacuum ultra-violet sensitive Fondazione Bruno Kessler VUVHD3 SiPMs specifically designed for nEXO, as well as new measurements on new test samples of previously characterised Hamamatsu VUV4 Multi Pixel Photon Counters (MPPCs). Various SiPM and MPPC parameters, such as dark noise, gain, direct crosstalk, correlated avalanches and photon detection efficiency were measured as a function of the applied over voltage and wavelength at liquid xenon temperature (163~K). The results from this study are used to provide updated estimates of the achievable energy resolution at the decay $Q$-value for the nEXO design.