Simons Observatory Large Aperture Telescope Receiver Design Overview

TL;DR

The paper presents the design of the large aperture telescope receiver for the Simons Observatory, highlighting its innovative features, technical challenges, and solutions to enable high-sensitivity cosmic microwave background measurements.

Contribution

It introduces the design of the largest CMB receiver to date, detailing solutions for technical challenges and its potential impact on future CMB experiments.

Findings

Design of a 2.4 m cryostat for CMB observations

Accommodation of thirteen optics tubes with thousands of TES bolometers

Addressing technical challenges in large-scale cryogenic receiver design

Abstract

The Simons Observatory (SO) will make precision temperature and polarization measurements of the cosmic microwave background (CMB) using a series of telescopes which will cover angular scales between one arcminute and tens of degrees and sample frequencies between 27 and 270 GHz. Here we present the current design of the large aperture telescope receiver (LATR), a 2.4 m diameter cryostat that will be mounted on the SO 6 m telescope and will be the largest CMB receiver to date. The cryostat size was chosen to take advantage of the large focal plane area having high Strehl ratios, which is inherent to the Cross-Dragone telescope design. The LATR will be able to accommodate thirteen optics tubes, each having a 36 cm diameter aperture and illuminating several thousand transition-edge sensor (TES) bolometers. This set of equipment will provide an opportunity to make measurements with unparalleled sensitivity. However, the size and complexity of the LATR also pose numerous technical challenges. In the following paper, we present the design of the LATR and include how we address these challenges. The solutions we develop in the process of designing the LATR will be informative for the general CMB community, and for future CMB experiments like CMB-S4.