Thermal Design and Characterization of Transition-Edge Sensor (TES) Bolometers for Frequency-Domain Multiplexing

• Published in: IEEE transactions on applied superconductivity Vol. 19; no. 3; pp. 496 - 500
• Main Authors: Lueker, M., Benson, B.A., Chang, C.L., Hsiao-Mei Cho, Dobbs, M., Holzapfel, W.L., Lanting, T., Lee, A.T., Mehl, J., Plagge, T., Shirokoff, E., Spieler, H.G., Vieira, J.D.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01-06-2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Bandwidth; Bolometer; Bolometers; Circuit properties; Circuit stability; Cosmic microwave background; Coupling circuits; Detectors; Electric, optical and optoelectronic circuits; Electrical engineering. Electrical power engineering; Electromagnets; Electronic circuits; Electronics; Exact sciences and technology; Feedback; Instruments; multiplexer; Multiplexing; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Sensor phenomena and characterization; SQUIDs; Superconducting devices; Switching, multiplexing, switched capacity circuits; Thermal coupling; Thermal design; Thermal sensors; Thermoelectric, pyroelectric devices, etc; transition-edge; Various equipment and components; Thermal characteristic; Telescope; transition-edge; Instruments; Multiplexer; Thermal detector; Measurement sensor; Thermal behavior; Feedback regulation; System design; Frequency domain method; Receiver; Experimental study; Frequency division multiplexing; Readout electronics; Thermoelectric properties; Sensitivity; Superconducting quantum interferometer device; Bolometer; Readout systems
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2009.2018036

In contemporary cosmic microwave background experiments, bolometric detectors are often background limited, and in this case the sensitivity of instruments can only be improved by increasing the number of background-limited detectors, and so contemporary TES receivers contain as many pixels as possible. Frequency-domain multiplexing (fMUX) is one strategy for reading out many detectors with one SQUID. For any readout system, it is important to carefully evaluate the thermal design of detector, in conjunction with the readout bandwidth, in order to ensure stable electro-thermal feedback (ETF). We demonstrate a novel technique for characterizing the thermal circuit of our detectors, using am AC-bias and the fMUX electronics. This technique is used to study the internal thermal coupling of a TES bolometer. We illustrate how the insights gathered by this technique have been instrumental in improving the stability of our multiplexed detectors for the south pole telescope (SPT).