NPA Seminar: Cyndia Yu, Stanford University, “The Microwave SQUID Multiplexer for Cosmic Microwave Background Measurements”

I will present the development and demonstration of the microwave SQUID multiplexer for cosmic microwave background observatories and discuss some of the science enabled by these large-scale focal planes. As CMB experiments become ever more sensitive, devising methods to maximize detector count will become ever more urgent. The microwave SQUID multiplexer (umux) enables multiplexing factors in the 100s or even 1000s by coupling each detector to a unique superconducting microwave resonator. The room-temperature readout is achieved via custom electronics sporting GHz-frequency ADCs and DACs to monitor the state of each resonator individually. I will first discuss the development of umux from a laboratory concept to a first on-sky CMB demonstration with the Keck Array in 2019 and subsequent development for the upcoming Simons Observatory, set to begin observations in 2023. I will then present new BICEP3 observations and preliminary sensitivity to cosmology enabled by such large CMB focal planes. Finally, I will share some future directions for the umux system including low-background rare event searches, x-ray astrophysics, and quantum-enhanced dark matter experiments.
Lunch with the speaker will be provided from 12-1 p.m. for those who RSVP by 11 a.m. on Wednesday, November 16th: https://tinyurl.com/npa-signup
Host: Fernando Flor (fernando.flor@yale.edu)