The Simons Observatory: Design, Optimization, and Performance of Low Frequency Detectors

TL;DR

The paper details the design, optimization, and testing of low-frequency detectors for the Simons Observatory, aiming to improve measurements of the cosmic microwave background and foreground characterization.

Contribution

It introduces the design and testing of low-frequency sinuous antenna TES bolometers for the SO, a novel implementation for CMB foreground analysis.

Findings

Successful development of 27 and 39 GHz detector arrays

Performance metrics indicating readiness for deployment

Enhanced capability for Galactic synchrotron characterization

Abstract

The Simons Observatory (SO) is a cosmic microwave background (CMB) experiment located in the Atacama Desert in Chile that will make precise temperature and polarization measurements over six spectral bands ranging from 27 to 285 GHz. Three small aperture telescopes (SATs) and one large aperture telescope (LAT) will house $\sim$60,000 detectors and cover angular scales between one arcminute and tens of degrees. We present the performance of the dichroic, low-frequency (LF) lenslet-coupled sinuous antenna transition-edge sensor (TES) bolometer arrays with bands centered at 27 and 39 GHz. The LF focal plane will primarily characterize Galactic synchrotron emission as a critical part of foreground subtraction from CMB data. We will discuss the design, optimization, and current testing status of these pixels.