The Simons Observatory: Development and Validation of the Large Aperture Telescope Receiver

TL;DR

The paper details the development and validation of the Large Aperture Telescope Receiver (LATR) for the Simons Observatory's large-aperture telescope, demonstrating it meets sensitivity, cryogenic, and mechanical requirements for advanced CMB observations.

Contribution

It introduces the design, testing, and validation of the LATR, a critical component enabling high-sensitivity CMB measurements with the SO's large-aperture telescope.

Findings

LATR meets cryogenic and mechanical specifications.

LATR maintains low baseline readout noise.

LATR can deploy up to 62,000 TES detectors.

Abstract

The Simons Observatory (SO) is a ground-based cosmic microwave background (CMB) survey experiment that consists of three 0.5 m small-aperture telescopes (SATs) and one 6 m large-aperture telescope (LAT), sited at an elevation of 5200 m in the Atacama Desert in Chile. In order to meet the sensitivity requirements set for next-generation CMB telescopes, the LAT will deploy 30,000 transition edge sensor (TES) detectors at 100 mK across 7 optics tubes (OT), all within the Large Aperture Telescope Receiver (LATR). Additionally, the LATR has the capability to expand to 62,000 TES across 13 OTs. The LAT will be capable of making arcminute-resolution observations of the CMB, with detector bands centered at 30, 40, 90, 150, 230, and 280 GHz. We have rigorously tested the LATR systems prior to deployment in order to fully characterize the instrument and show that it can achieve the desired sensitivity levels. We show that the LATR meets cryogenic and mechanical requirements, and maintains acceptably low baseline readout noise.