A High-Capacity Microwave SQUID Multiplexer Chip Screening System

Published

March 21, 2023

Author(s)

Zachary Whipps, Jake A. Connors, Bradley Dober, Johannes Hubmayr, John Mates, Caleb Wheeler, John Groh, Jason Austermann, Leila Vale, Gene C. Hilton, Jiansong Gao, Shannon Duff, Joel Ullom, Ed Denison

Abstract

The microwave SQUID multiplexer ($\mu$MUX) is a high channel-count multiplexer that, when coupled to low-temperature detectors such as Transition Edge Sensor (TES) Bolometers, has applications across astronomy and physics. Our primary application is for the Simons Observatory, an array of CMB polarimeters utilizing over 70,000 $\mu$MUX readout channels, located in the Atacama Desert. To facilitate the delivery of high-quality multiplexers to the project, we have developed a high-throughput microwave SQUID screening measurement system, capable of measuring microwave devices operating over the frequency range of 4-8GHz. Here we present the hardware design comprised of a cryogen-free 100mK 2-stage Adiabatic Demagnetization Refrigerator (ADR) cryostat, microwave packages which hold $\mu$MUX chips, and the microwave readout chain necessary to do these measurements. In addition, we describe the screening protocols and show example results.

Citation

Journal of Low Temperature Physics

Volume

211

Pub Type

Journals

Download Paper

https://doi.org/10.1007/s10909-023-02954-6

Local Download

Keywords

SQUID, microwave SQUID

Citation

Whipps, Z. , Connors, J. , Dober, B. , Hubmayr, J. , Mates, J. , Wheeler, C. , Groh, J. , Austermann, J. , Vale, L. , Hilton, G. , Gao, J. , Duff, S. , Ullom, J. and Denison, E. (2023), A High-Capacity Microwave SQUID Multiplexer Chip Screening System, Journal of Low Temperature Physics, [online], https://doi.org/10.1007/s10909-023-02954-6, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933716 (Accessed October 14, 2025)