Testing magnetic interference between TES detectors and the telescope environment for future CMB satellite missions
Testing magnetic interference between TES detectors and the telescope environment for future CMB satellite missions
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为未来 CMB 卫星任务测试 TES 探测器与望远镜环境之间的磁干扰
DOI：
10.1117/12.2630091
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Tommaso Ghigna
中科院分区：
文献类型：
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作者：
上村尚平;大木洋;Tommaso Ghigna;Tommaso Ghigna
几个即将到来的CMB实验中最常见的两个组成部分是大型超导TES（过渡边缘传感器）探测器阵列和偏振调制器单元，例如连续旋转半波板（HWP）。高检测器计数对于增加仪器原始灵敏度是必要的，然而过去的实验已经表明，系统效应正在成为达到检测原始B模式所需灵敏度的主要限制因素之一。因此，偏振调制器近年来已经变得流行，以减轻几种系统效应。基于HWP技术的偏振调制器需要旋转机构来旋转板并调制输入的偏振信号。为了最大限度地减少旋转机构的散热，这对于像LiteBIRD这样的空间使命来说是一个严格的要求，我们可以采用磁悬浮轴承来悬浮转子并实现无接触旋转。这种技术的缺点是由这些系统产生的相关磁场。在本文中，我们调查的TES检测器原型的影响，并发现没有检测到的Tc变化，由于施加恒定（DC）磁场，和非零TES响应变化（AC）磁场。我们量化的最坏情况下TES响应所施加的交流磁场的105 pA/G，并给出了一个初步的解释的拾取机制。
The two most common components of several upcoming CMB experiments are large arrays of superconductive TES (Transition-Edge Sensor) detectors and polarization modulator units, e.g. continuously-rotating Half-Wave Plates (HWP). A high detector count is necessary to increase the instrument raw sensitivity, however past experiments have shown that systematic effects are becoming one of the main limiting factors to reach the sensitivity required to detect primordial B-modes. Therefore, polarization modulators have become popular in recent years to mitigate several systematic effects. Polarization modulators based on HWP technologies require a rotating mechanism to spin the plate and modulate the incoming polarized signal. In order to minimize heat dissipation from the rotating mechanism, which is a stringent requirement particularly for a space mission like LiteBIRD, we can employ a superconductive magnetic bearing to levitate the rotor and achieve contactless rotation. A disadvantage of this technique is the associated magnetic fields generated by those systems. In this paper we investigate the effects on a TES detector prototype and find no detectable Tc variations due to an applied constant (DC) magnetic field, and a non-zero TES response to varying (AC) magnetic fields. We quantify a worst-case TES responsivity to the applied AC magnetic field of ∼ 105 pA/G, and give a preliminary interpretation of the pick-up mechanism.