Highly-multiplexed microwave SQUID readout using the SLAC Microresonator Radio Frequency (SMuRF) Electronics for Future CMB and Sub-millimeter Surveys

Abstract

The next generation of cryogenic CMB and submillimeter cameras under development require densely instrumented sensor arrays to meet their science goals. The readout of large numbers ($\sim$10,000--100,000 per camera) of sub-Kelvin sensors, for instance as proposed for the CMB-S4 experiment, will require substantial improvements in cold and warm readout techniques. To reduce the readout cost per sensor and integration complexity, efforts are presently focused on achieving higher multiplexing density while maintaining readout noise subdominant to intrinsic detector noise. Highly-multiplexed cold readout technologies in active development include Microwave Kinetic Inductance Sensors (MKIDs) and microwave rf-SQUIDs. Both exploit the high quality factors of superconducting microwave resonators to densely channelize sub-Kelvin sensors into the bandwidth of a microwave transmission line. We present advancements in the development of a new warm readout system for microwave SQUID multiplexing, the SLAC Superconducting Microresonator RF electronics, or SMuRF. The SMuRF system is unique in its ability to track each tone, minimizing the total RF power required to read out each resonator, thereby significantly reducing the linearity requirements on the cold and warm readout. Here, we present measurements of the readout noise and linearity of the first full SMuRF system, including a demonstration of closed-loop tone tracking on a 528 channel cryogenic microwave SQUID multiplexer. SMuRF is being explored as a potential readout solution for several future CMB projects including Simons Observatory, BICEP Array, CCAT-prime, Ali-CPT, and CMB-S4. Parallel development of the platform is underway to adapt SMuRF to read out both MKID and fast X-ray TES calorimeter arrays.

arXiv comment16 pages, 5 figures

References in corpus (6)

• Advanced ACTPol Cryogenic Detector Arrays and Readout
• The POLARBEAR-2 and the Simons Array Experiment
• A readout for large arrays of Microwave Kinetic Inductance Detectors
• Multiplexed Readout for 1000-pixel Arrays of Microwave Kinetic Inductance Detectors
• Characterization of the Mid-Frequency Arrays for Advanced ACTPol
• SLAC Microresonator Radio Frequency (SMuRF) Electronics for Read Out of Frequency-Division-Multiplexed Cryogenic Sensors

Cited by in corpus (13)

• BICEP Array: a multi-frequency degree-scale CMB polarimeter
• A Microwave SQUID Multiplexer Optimized for Bolometric Applications
• SLAC Microresonator RF (SMuRF) Electronics: A tone-tracking readout system for superconducting microwave resonator arrays
• 2017 upgrade and performance of BICEP3: a 95GHz refracting telescope for degree-scale CMB polarization
• Simons Observatory Microwave SQUID Multiplexing Readout -- Cryogenic RF Amplifier and Coaxial Chain Design
• The Simons Observatory 220 and 280 GHz Focal-Plane Module: Design and Initial Characterization
• Characterization of Transition Edge Sensors for the Simons Observatory
• Simons Observatory Focal-Plane Module: In-lab Testing and Characterization Program
• Demonstration of a 1820 channel multiplexer for transition-edge sensor bolometers
• Bandwidth and Aliasing in the Microwave SQUID Multiplexer
• BFORE: A CMB Balloon Payload to Measure Reionization, Neutrino Mass, and Cosmic Inflation
• The Simons Observatory: A Minimum-Cost Matching Algorithm for Pairing Measured Resonances with Designed Detectors
• The Galaxy Evolution Probe