论文标题
放射性诱导的暗计数在80 mk处使用钨过渡边缘传感器的单个近红外光子检测
Radioactivity induced dark count rate for single near-infrared photon detection with a tungsten transition edge sensor at 80 mK
论文作者
论文摘要
钨超导过渡传感器（TES）的内在背景计数速率较低，使用这些传感器的热量表可以解析单个光子的能量。这些事实使传感器在对新过程和粒子的背景搜索中特别有趣。在此贡献中，已经研究了钨TE的固有背景。在排除了其他来源（例如宇宙MUON，热背景）与观察到的背景速率相关的$ 10^{ - 4} $ 〜S $^{ - 1} $用于检测波长为1064 nm的光子的$，我们研究了自然放射性的影响。使用压迫仪外安装的伽马发射器的专用测量已用于估计TES设置对电离辐射的灵敏度。我们发现，在放射性源的存在下，确实可以观察到增加的背景。在选择了填充我们的信号区域的事件之后，在近红外检测单个光子检测之后，伽马射线产生的事件中约有0.5％与1064〜nm波长的单个光子所致的事件似乎没有区别。该比率与TES检测到的剩余背景观察到的比率是一致的，该剩余背景的速度为$ 10^{ - 4} $ 〜S $^{ - 1} $。从中，我们得出的结论是，可以通过自然放射性来解释信号区域中观察到的背景计数的大部分。
The intrinsic background count rate of tungsten superconducting transition-edge sensors (TES) is low, and the calorimeters using these sensors can resolve the energy of single photons. These facts make the sensors particularly interesting for the background-limited searches of new processes and particles. In this contribution, the intrinsic background of a tungsten TES has been investigated. After excluding other sources (e.g., cosmic muons, thermal background) relevant for the observed background rate of $10^{-4}$~s$^{-1}$ for the detection of photons with a wave length of 1064 nm, we investigate the impact of natural radioactivity. Dedicated measurements using gamma-emitters mounted outside the cryostat have been used to estimate the sensitivity of the TES setup for ionizing radiation. We have found that indeed an increased background can be observed in the presence of the radioactive sources. After selecting events which populate our signal region tuned for single photon detection at near-infrared, roughly 0.5% of the events produced by gamma-rays appear indistinguishable from those due to single photons with 1064~nm wave length. This ratio is consistent with that observed for the residual background detected with the TES at a rate of $10^{-4}$~s$^{-1}$. From this, we conclude that the bulk of the observed background count-rate in the signal region can be explained by natural radioactivity.
