Time-division SQUID multiplexers with reduced sensitivity to external magnetic fields
Greg Stiehl, Hsiao-Mei Cho, Gene C. Hilton, Kent D. Irwin, John A. Mates, Carl D. Reintsema, Barry L. Zink
We have developed time-division SQUID multiplexers to read out large arrays of transition-edge sensor (TES) detectors. These multiplexers are used in many applications that require exquisite control of systematic error. One important application is the measurement of the polarization of the cosmic microwave background (CMB). CMB polarization measurements require exquisite control of systematic error sources since the signals of interest are many orders of magnitude smaller than the amplitude of the CMB. One major potential source of systematic error is the pickup of external magnetic fields by the SQUID multiplexers. Thus, we present measurements of the field sensitivity figure of merit, effective area, for three NIST SQUID multiplexer designs, and a scheme for separating out the 1st and 2nd stage contributions. These designs include a new variety with improved gradiometry, which has been shown to have more than an order of magnitude reduction in external field sensitivity.
, Cho, H.
, Hilton, G.
, Irwin, K.
, Mates, J.
, Reintsema, C.
and Zink, B.
Time-division SQUID multiplexers with reduced sensitivity to external magnetic fields, IEEE Transactions on Applied Superconductivity, [online], https://doi.org/10.1109/TASC.2010.2091483
(Accessed December 2, 2023)