Bias conditions of dc-SQUIDs for a time-domain SQUID multiplexer

Published

February 1, 2004

Author(s)

Joern Beyer, Dietmar Drunge, Kent D. Irwin

Abstract

SQUID multiplexers can be used to read out arrays of cryogenic microcalorimeters and bolometers. Time-domain dc-SQUID multiplexer configurations use an individual first-stage dc-SQUID for each detector of an array. The biasing conditions of these first-stage SQUIDs significantly affect the performance of the SQUID multiplexer. We analyze the bias conditions of the first-stage SQUIDs in terms of the total multiplexer noise and bandwidth. We present an analysis and experimental study of the operational parameters of a first-stage dc-SQUID under varied vias conditions. This analysis includes a direct measurement of the SQUID dynamic resistance and the flux noise of the SQUID biased over the range from voltage bias to current bias. Our measurements show that a matched bias of the first-stage SQUIDs improves the system noise performance as well as the first-stage bandwidth.

Citation

Review of Scientific Instruments

Volume

75

Pub Type

Journals

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Keywords

microcalorimeter, multiplexer, SQUID

Citation

Beyer, J. , Drunge, D. and Irwin, K. (2004), Bias conditions of dc-SQUIDs for a time-domain SQUID multiplexer, Review of Scientific Instruments, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=31440 (Accessed October 9, 2025)