Microwave SQUID multiplexer demonstration for cosmic microwave background imagers
Microwave SQUID multiplexer demonstration for cosmic microwave background imagers
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DOI：
10.1063/1.5008527
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发表时间：
2017-12-11
影响因子：
4
通讯作者：
Ullom, J. N.
中科院分区：
文献类型：
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作者：
Dober, B.;Becker, D. T.;Ullom, J. N.
微波超导量子干涉器件（SQUID）多路复用器（MU MUX）耦合到过渡边缘传感器（TES）测辐射热计，已优化宇宙微波背景（CMB）观测的关键性能特性证明。在一个64通道的演示中，我们表明，亩多路复用器产生一个白色，输入参考电流噪声水平为29 pA的微波探头音调功率为-77 dB，这是远低于预期的基本探测器和光子噪声源的地面CMB优化测辐射热计。可忽略不计的光子负载操作，我们测量98 pA的TES耦合通道偏置在65%的传感器正常电阻。该噪声水平与从测辐射热计热波动预测的噪声水平一致（即，声子）噪声。此外，功率谱密度在下至类似于100 mHz的频率范围内是白色的，这使得能够在约束暴胀物理学的大角度尺度上进行CMB映射。此外，我们报告的串扰测量表明低于0.3%的水平，这是小于部署的CMB成像器中的多路复用读出系统的串扰水平。这些测量结果表明，mu mux作为一个可行的读出技术，为未来的CMB成像仪器。
Key performance characteristics are demonstrated for the microwave superconducting quantum interference device (SQUID) multiplexer (mu mux) coupled to transition edge sensor (TES) bolometers that have been optimized for cosmic microwave background (CMB) observations. In a 64-channel demonstration, we show that the mu mux produces a white, input referred current noise level of 29 pA at a microwave probe tone power of - 77 dB, which is well below the expected fundamental detector and photon noise sources for a ground-based CMB-optimized bolometer. Operated with negligible photon loading, we measure 98 pA in the TES-coupled channels biased at 65% of the sensor normal resistance. This noise level is consistent with that predicted from bolometer thermal fluctuation (i.e., phonon) noise. Furthermore, the power spectral density is white over a range of frequencies down to similar to 100 mHz, which enables CMB mapping on large angular scales that constrain the physics of inflation. Additionally, we report cross-talk measurements that indicate a level below 0.3%, which is less than the level of cross-talk from multiplexed readout systems in deployed CMB imagers. These measurements demonstrate the mu mux as a viable readout technique for future CMB imaging instruments.