Jul 22 – 26, 2019
Europe/Rome timezone

Demonstration of a Kilopixel-scale multiplexing factor for TES bolometers using microwave SQUID readout

Jul 24, 2019, 9:15 AM
Auditorium G. Testori (Milano)

Auditorium G. Testori


Piazza Città di Lombardia, 1, 20124 Milano MI
Oral Presentation Detector readout, signal processing, and related technologies Orals LM 002


Dr Bradley Dober (University of Colorado Boulder)


The next generation of cosmic microwave background (CMB) imagers are nearly upon us. Large millimeter wave cryogenic receivers under development for the Simons Observatory, ALI-CPT, CCAT-prime, and BICEP array will each couple tens of thousands of transition-edge sensors (TES) onto the sky. These large sensor counts will be achieved by tiling multiple 150mm-diameter multichroic detector arrays into focal planes. The microwave SQUID multiplexer (μMUX) is a novel readout technique designed to address the complexities of reading out high detector wafer counts in densely tiled focal planes. The sensitivity, low cross-talk, extremely high multiplexing density of TES bolometers, and compact physical footprint make the μMUX well-suited for this goal. μMUX inductively couples the signal from TES bolometers to a frequency change in a quarter-wave resonator via a dissipationless rf-SQUID. Each multiplexing channel couples the TES to its own unique resonant frequency between 4-8 GHz. By closely spacing the resonant frequencies and coupling to a common CPW feedline, over 2000 TES bolometers may be read out on a pair of coaxial cables. We present the next iteration of the μMUX design, with a factor of two and three improvements in physical and spectral channel density, respectively. These resonators are nominally spaced 2 MHz apart, have a bandwidth of 100kHz, and have an input referred current noise of 35 pA/√Hz, which is well suited for a background-limited TES bolometer. Finally, we will present the latest results from a 2000 channel mux demonstration. These results will include discussions on readout noise, stability, yield, crosstalk, and TES-coupled performance.

Student (Ph.D., M.Sc. or B.Sc.) N
Less than 5 years of experience since completion of Ph.D Y

Primary author

Dr Bradley Dober (University of Colorado Boulder)


Dr Zeeshan Ahmed (SLAC National Accelerator Laboratory) Jason Austermann (University of Colorado-Boulder & NIST-Boulder) Daniel Becker (National Institute of Standards and Technology) Dr Douglas Bennett (NIST) Dr David Brown (SLAC National Accelerator Laboratory) Mr Saptarshi Chaudhuri (Stanford University) Ari Cukierman (Stanford University) Dr Hsiao-Mei Cho (SLAC National Accelerator Laboratory) Dr John M D'Ewart (SLAC National Accelerator Laboratory) Shannon Duff (NIST-Boulder) Dr John E. Dusatko (SLAC National Accelerator Laboratory) Dr Sofia Fatigoni (Department of Physics and Astronomy, University of British Columbia) Dr Josef C. Frisch (SLAC National Accelerator Laboratory) Jiansong Gao (NIST) Dr Johnathon Gard (NIST) Dr Mark Halpern (Department of Physics and Astronomy, University of British Columbia) Dr Shawn W. Henderson (SLAC National Accelerator Laboratory) Gene Hilton (NIST) Dr Hannes Hubmayr (NIST) Kent Irwin (Stanford University) Dr Ethan D. Karpel (Department of Physics, Stanford University) Dr Sarah S. Kernasovskiy (Department of Physics, Stanford University) Stephen Kuenstner (Stanford University) Dale Li (SLAC National Accelerator Laboratory) Prof. Chao-Lin Kuo (Stanford University) John A. B. Mates (National Institute of Standards and Technology) Dr Stephen R. Smith (SLAC National Accelerator Laboratory) Joel Ullom (NIST) Jeff Van Lanen (NIST-Boulder) Dr Daniel D. Van Winkle (SLAC National Accelerator Laboratory) Michael Vissers (NIST-Boulder) Cyndia Yu (Stanford University) Dr Edward Young (Department of Physics, Stanford University)

Presentation materials