The Simons Observatory Microwave SQUID Multiplexing Detector Module Design

Abstract Advances in cosmic microwave background (CMB) science depend on increasing the number of sensitive detectors observing sky. New instruments deploy large arrays superconducting transition-edge sensor (TES) bolometers tiled densely into ever larger focal planes. High multiplexing factors reduce thermal loading cryogenic receivers and simplify their design. We present design focal-plane modules with an order magnitude higher factor than has previously been achieved TES bolometers. focus novel cold readout component, which employs SQUID ( ? mux). Simons Observatory will use 49 containing 70,000 to make exquisitely measurements CMB. validate module design, presenting component without a prototype detector array 1728 polarization-sensitive coupled feedhorns. The achieves 95% yield 910 factor. median white noise each channel is 65 pA / Hz . This impacts projected SO mapping speed by <8%, less assumed sensitivity projections. results full functionality module. discuss measured performance context requirements, are exceeded.