The Simons Observatory (SO) is a cosmic microwave background (CMB) survey
experiment that includes small-aperture telescopes (SATs) observing from an
altitude of 5,200 m in the Atacama Desert in Chile. The SO SATs will cover six
spectral bands between 27 and 280 GHz to search for primordial B-modes to a
sensitivity of σ(r)=0.002, with quantified systematic errors well below
this value. Each SAT is a self-contained cryogenic telescope with a 35^∘
field of view, 42 cm diameter optical aperture, 40 K half-wave plate, 1 K
refractive optics, and <0.1 K focal plane that holds >12,000 TES detectors.
We describe the nominal design of the SATs and present details about the
integration and testing for one operating at 93 and 145 GHz.
