Microwave multiplexing on the Keck Array

Abstract

We describe an on-sky demonstration of a microwave-multiplexing readout system in one of the receivers of the Keck Array, a polarimetry experiment observing the cosmic microwave background at the South Pole. During the austral summer of 2018-2019, we replaced the time-division multiplexing readout system with microwave-multiplexing components including superconducting microwave resonators coupled to radio-frequency superconducting quantum interference devices at the sub-Kelvin focal plane, coaxial-cable plumbing and amplification between room temperature and the cold stages, and a SLAC Microresonator Radio Frequency system for the warm electronics. In the range 5-6 GHz, a single coaxial cable reads out 528 channels. The readout system is coupled to transition-edge sensors, which are in turn coupled to 150-GHz slot-dipole phased-array antennas. Observations began in April 2019, and we report here on an initial characterization of the system performance.

9 pages, 11 figures, Accepted by the Journal of Low Temperature Physics (Proceedings of the 18th International Workshop on Low Temperature Detectors)

References in corpus (4)

• Signature of Gravity Waves in Polarization of the Microwave Background
• Advanced ACTPol Cryogenic Detector Arrays and Readout
• First Monte Carlo global QCD analysis of pion parton distributions
• Microwave SQUID Multiplexer demonstration for Cosmic Microwave Background Imagers

Cited by in corpus (11)

• A Microwave SQUID Multiplexer Optimized for Bolometric Applications
• The Simons Observatory microwave SQUID multiplexing detector module design
• SLAC Microresonator RF (SMuRF) Electronics: A tone-tracking readout system for superconducting microwave resonator arrays
• Transition Edge Sensors: Physics and Applications
• Cleaning our own Dust: Simulating and Separating Galactic Dust Foregrounds with Neural Networks
• Design and performance of the first BICEP Array receiver
• Optical characterization of the Keck Array and BICEP3 CMB Polarimeters from 2016 to 2019
• Crosstalk effects in microwave SQUID multiplexed TES bolometer readout
• Demonstration of a 1820 channel multiplexer for transition-edge sensor bolometers
• Bandwidth and Aliasing in the Microwave SQUID Multiplexer
• The Simons Observatory: Studies of Detector Yield and Readout Noise From the First Large-Scale Deployment of Microwave Multiplexing at the Large Aperture Telescope