Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

A 300-mK Test Bed for Rapid Characterization of Microwave SQUID Multiplexing Circuits



Abigail L. Wessels, Daniel T. Becker, Douglas A. Bennett, Johnathon D. Gard, Johannes Hubmayr, Norman Jarosik, Vincent Y. Kotsubo, John A. Mates, Joel N. Ullom


Microwave SQUID multiplexing is a promising technique for multiplexing large arrays of transition edge sensors. A major bottleneck in the development and distribution of microwave SQUID multiplexer chips occurs in the time-intensive design testing and quality assurance stages. To obtain useful RF measurements, these devices must be cooled to temperatures below 500 mK. The need for a more efficient system to screen microwave multiplexer chips has grown as the number of chips requested by collaborators per year reaches into the hundreds. We have therefore assembled a test bed for microwave SQUID circuits, which decreases screening time for four 32-channel chips from 24 h in an adiabatic demagnetization refrigerator to approximately 5 h in a helium dip probe containing a closed cycle 3He sorption refrigerator. We discuss defining characteristics of these microwave circuits and the challenges of establishing an efficient testing setup for them.
Journal of Low Temperature Physics


multiplexing, SQUID, screening, microwave, transition edge sensors, He, refrigerator, closed cycle, screening time, testing, design, temperature


Wessels, A. , Becker, D. , Bennett, D. , Gard, J. , Hubmayr, J. , Jarosik, N. , Kotsubo, V. , Mates, J. and Ullom, J. (2018), A 300-mK Test Bed for Rapid Characterization of Microwave SQUID Multiplexing Circuits, Journal of Low Temperature Physics, [online], (Accessed February 27, 2024)
Created August 3, 2018, Updated June 29, 2020