The Simons Observatory: Instrument overview

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 1 arcminute and tens of degrees, contain over 40,000 detectors, and sample frequencies between 27 and 270 GHz. SO will consist of a six-meter-aperture telescope coupled to over 20,000 detectors along with an array of half-meter aperture refractive cameras, coupled to an additional 20,000+ detectors. The unique combination of large and small apertures in a single CMB observatory, which will be located in the Atacama Desert at an altitude of 5190 m, will allow us to sample a wide range of angular scales over a common survey area. SO will measure fundamental cosmological parameters of our universe, find high redshift clusters via the Sunyaev-Zeldovich effect, constrain properties of neutrinos, and seek signatures of dark matter through gravitational lensing. The complex set of technical and science requirements for this experiment has led to innovative instrumentation solutions which we will discuss. The large aperture telescope will couple to a cryogenic receiver that is 2.4 m in diameter and over 2 m long, creating a number of interesting technical challenges. Concurrently, we are designing an array of half-meter-aperture cryogenic cameras which also have compelling design challenges. We will give an overview of the drivers for and designs of the SO telescopes and the cryogenic cameras that will house the cold optical components and detector arrays.