2017 upgrade and performance of BICEP3: a 95GHz refracting telescope for degree-scale CMB polarization

• Published in: Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX
• Main Authors: Kang, Jae Hwan, Aikin, R. W., Bock, J. J., Brevik, J. A., Hildebrandt, S. R., Hui, H., Kefeli, S., Lueker, M., Moncelsi, L., O'Brient, R., Schillaci, A., Soliman, A., Staniszewski, Z. K., Steinbach, B., Teply, G. P., Wandui, A., Zhang, C.
• Other Authors: Zmuidzinas, Jonas, Gao, Jian-Rong
• Format: Book Part
• Language: unknown
• Published: Society of Photo-optical Instrumentation Engineers (SPIE) 2018
• Subjects: Cosmic Microwave Background; Inflation; Gravitational Waves; Polarization; BICEP3; Keck Array; Antarctic; Austral; Canada; South Pole; Antarc*; South pole
• Online Access: https://doi.org/10.1117/12.2313854

BICEP3 is a 520mm aperture on-axis refracting telescope observing the polarization of the cosmic microwave background (CMB) at 95GHz in search of the B-mode signal originating from in ationary gravitational waves. BICEP3's focal plane is populated with modularized tiles of antenna-coupled transition edge sensor (TES) bolometers. BICEP3 was deployed to the South Pole during 2014-15 austral summer and has been operational since. During the 2016-17 austral summer, we implemented changes to optical elements that lead to better noise performance. We discuss this upgrade and show the performance of BICEP3 at its full mapping speed from the 2017 and 2018 observing seasons. BICEP3 achieves an order-of-magnitude improvement in mapping speed compared to a Keck 95GHz receiver. We demonstrate 6.6μK√s noise performance of the BICEP3 receiver. © 2018 Society of Photo-optical Instrumentation Engineers (SPIE). The Bicep/Keck projects have been made possible through a series of grants from the National Science Foundation including 0742818, 0742592, 1044978, 1110087, 1145172, 1145143, 1145248, 1639040, 1638957, 1638978, 1638970, & 1726917, by the Gordon and Betty Moore Foundation, by the Keck Foundation, and by the grant 55802 from John Templeton Foundation. The development of antenna-coupled detector technology was supported by the JPL Research and Technology Development Fund and NASA Grants 06-ARPA206-0040, 10-SAT10-0017, 12-SAT12-0031, 14-SAT14-0009 & 16-SAT16-0002. The development and testing of focal planes were supported by the Gordon and Betty Moore Foundation at Caltech. Readout electronics were supported by a Canada Foundation for Innovation grant to UBC. The computations in this paper were run on the Odyssey cluster supported by the FAS Science Division Research Computing Group at Harvard University. The analysis effort at Stanford and SLAC is partially supported by the U.S. DoE Office of Science. We thank the staff of the U.S. Antarctic Program and in particular the South Pole Station without whose help ...