The Simons Observatory: Design and Initial Performance of the Detector Readout System for the Large-Aperture Telescope

@misc{satterthwaite2026simons,
  title = {{The Simons Observatory: Design and Initial Performance of the Detector Readout System for the Large-Aperture Telescope}},
  author = {Thomas P. Satterthwaite and Tristan Pinsonneault-Marotte and Shawn W. Henderson and Zeeshan Ahmed and Kam Arnold and Declan Baker and Andrew Bazarko and Josh Borrow and Michael L. Brown and Mark Devlin and Simon Dicker and Peter N. Dow and Shannon M. Duff and Daniel Dutcher and John C. Groh and Saianeesh K. Haridas and Kathleen Harrington and Erin Healy and Johannes Hubmayr and Bradley R. Johnson and Brian Keating and Anna M. Kofman and Adrian T. Lee and Alex Manduca and Aashrita Mangu and Jenna E. Moore and Michael D. Niemack and Sandra O'Neill and John Orlowski-Scherer and Yudai Seino and Mufan Shao and Carlos Sierra and Max Silva-Feaver and Suzanne Staggs and Eve M. Vavagiakis and Yuhan Wang and Edward J. Wollack},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.39100},
  eprint = {2609.39100},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.39100},
}

TY  - UNPB
TI  - The Simons Observatory: Design and Initial Performance of the Detector Readout System for the Large-Aperture Telescope
AU  - Thomas P. Satterthwaite
AU  - Tristan Pinsonneault-Marotte
AU  - Shawn W. Henderson
AU  - Zeeshan Ahmed
AU  - Kam Arnold
AU  - Declan Baker
AU  - Andrew Bazarko
AU  - Josh Borrow
AU  - Michael L. Brown
AU  - Mark Devlin
AU  - Simon Dicker
AU  - Peter N. Dow
AU  - Shannon M. Duff
AU  - Daniel Dutcher
AU  - John C. Groh
AU  - Saianeesh K. Haridas
AU  - Kathleen Harrington
AU  - Erin Healy
AU  - Johannes Hubmayr
AU  - Bradley R. Johnson
AU  - Brian Keating
AU  - Anna M. Kofman
AU  - Adrian T. Lee
AU  - Alex Manduca
AU  - Aashrita Mangu
AU  - Jenna E. Moore
AU  - Michael D. Niemack
AU  - Sandra O'Neill
AU  - John Orlowski-Scherer
AU  - Yudai Seino
AU  - Mufan Shao
AU  - Carlos Sierra
AU  - Max Silva-Feaver
AU  - Suzanne Staggs
AU  - Eve M. Vavagiakis
AU  - Yuhan Wang
AU  - Edward J. Wollack
PY  - 2026
DA  - 2026/09/30
PB  - arXiv
DO  - 10.48550/arxiv.2609.39100
UR  - https://arxiv.org/abs/2609.39100
AB  - 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.
ER  -