The Simons Observatory: Design and Initial Performance of the Detector Readout System for the Large-Aperture Telescope
Year: 2026
Type: preprint
Abstract: We present the design, implementation, and initial performance of a highly multiplexed cryogenic superconducting detector readout system in the context of its deployment to the Simons Observatory large-aperture telescope (LAT). The Simons Observatory is a cosmic microwave background experiment located at 5,200 m in Chile's Atacama Desert. In addition to its 6 m LAT, whose broad range of science goals spans probing large-scale structure to searching for new Solar System objects, the observatory also currently includes three 0.42 m small-aperture telescopes, which search for signatures of primordial gravitational waves. Nearly 100,000 optically-coupled transition-edge sensor bolometers have been deployed across the observatory's four telescopes to enable these science goals. The readout systems for these telescopes use microwave frequency multiplexing to simultaneously read out 860 optically-coupled bolometers per transmission line. This is enabled by the large-scale fabrication of multiplexing chips which house radio-frequency superconducting quantum interference devices for each detector, and the development of room-temperature electronics to read out these bolometers. This has enabled the largest deployment of superconducting sensors for astronomical observations to date. This paper focuses on the design and implementation of the readout system for the 63,000 detectors in the LAT's cryogenic receiver. We present performance results from an early phase in the telescope's operation. We show that the readout system's performance enables the instrument to meet key benchmarks, including successful readout of 81.4% of its optically-coupled bolometers, which exceeds projections, and readout noise-equivalent current consistent with pre-deployment specifications.
Source: arXiv (Cornell University)
Authors: Satterthwaite, Thomas P., Pinsonneault-Marotte, Tristan, Henderson, Shawn W., Ahmed, Zeeshan, Arnold, Kam, Baker, Declan, Bazarko, Andrew, Borrow, Josh, Brown, Michael L., Devlin, Mark, Dicker, Simon, Dow, Peter N., Duff, Shannon M., Dutcher, Daniel, Groh, John C., Haridas, Saianeesh K., Harrington, Kathleen, Healy, Erin, Hubmayr, Johannes, Johnson, Bradley R., Keating, Brian, Kofman, Anna M., Lee, Adrian T., Manduca, Alex, Mangu, Aashrita, Moore, Jenna E., Niemack, Michael D., O'Neill, Sandra, Orlowski-Scherer, John, Seino, Yudai, Shao, Mufan, Sierra, Carlos, Silva-Feaver, Max, Staggs, Suzanne, Vavagiakis, Eve M., Wang, Yuhan, Wollack, Edward J.
Institutions: SLAC National Accelerator Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, University of California San Diego, University of Pennsylvania, Princeton University, University of Virginia, National Institute of Standards and Technology, University of Chicago, Lawrence Berkeley National Laboratory, University of California, Berkeley, Duke University, Yale University, Cornell University, Goddard Space Flight Center
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, Princeton University, National Energy Research Scientific Computing Center, University of Manchester, Science Foundation Ireland, Agencia Nacional de Investigación y Desarrollo, Science and Technology Facilities Council, High Energy Physics, Argonne National Laboratory, SLAC National Accelerator Laboratory
Awards: G102163711, G107546177, G1313983767, G1664757510, SO:UK - A major UK contribution to Simons Observatory, G2371548206, G262532246, G262962599, G2710870262, G303061748, G3075337988, G4235786860, G4269941704, G4654690619, G513797252, G5560389312, G5570207115, G618388848, Mid-scale RI-2: Advanced Millimeter Survey Instrumentation in Chile, G7086350903, G8581667079, G8726098666, G97770923
OpenAlex ID: W7215103310