The integration and testing program for the Simons Observatory Large Aperture Telescope optics tubes

Abstract

The Simons Observatory (SO) will be a CMB survey experiment with three small-aperture telescopes and one large-aperture telescope (the LAT), which will observe from the Atacama Desert in Chile. In total, SO will field over 60,000 TES bolometers in six spectral bands centered between 27 and 280 GHz. The 6 m LAT, targeting the smaller angular scales of the CMB, utilizes a cryogenic receiver (LATR) designed to house up to 13 individual optics tubes. The scientific objectives of the SO project requires these optics tubes to achieve high-throughput optical performance while maintaining exquisite control of systematic effects. We describe the integration and testing program for the LATR optics tubes being carried out to verify the design and assembly of the tubes before deployment. The program includes a quick turn-around single tube test cryostat. We discuss the optical design specifications the tubes for deployment and the suite of optical test equipment prepared for these measurements.