The Simons Observatory: the Large Aperture Telescope Receiver (LATR) Integration and Validation Results

Abstract

The Simons Observatory (SO) will observe the cosmic microwave background (CMB) from Cerro Toco in the Atacama Desert of Chile. The observatory consists of three 0.5 m Small Aperture Telescopes (SATs) and one 6 m Large Aperture Telescope (LAT), covering six frequency bands centering around 30, 40, 90, 150, 230, and 280 GHz. The SO observations will transform the understanding of our universe by characterizing the properties of the early universe, measuring the number of relativistic species and the mass of neutrinos, improving our understanding of galaxy evolution, and constraining the properties of cosmic reionization. 1 As a critical instrument, the Large Aperture Telescope Receiver (LATR) is designed to cool ∼ 60,000 transition-edge sensors (TES) 2 to < 100 mK on a 1.7 m diameter focal plane. The unprecedented scale of the LATR drives a complex