BICEP3: a 95 GHz refracting telescope for degree-scale CMB polarization

• Main Authors: Ahmed, Z., Amiri, M., Benton, S. J., Bock, J. J., Bowens-Rubin, R., Buder, I., Bullock, E., Connors, J., Filippini, J. P., Grayson, J. A., Halpern, M., Hilton, G. C., Hristov, V. V., Hui, H., Irwin, K. D., Kang, J., Karkare, K. S., Karpel, E., Kovac, J. M., Kuo, C. L., Netterfield, C. B., Nguyen, H. T., O'Brient, R., Ogburn, R. W., Pryke, C., Reintsema, C. D., Richter, S., Thompson, K. L., Turner, A. D., Vieregg, A. G., Wu, W. L. K., Yoon, K. W.
• Format: Text
• Language: unknown
• Published: arXiv 2014
• Subjects: Instrumentation and Methods for Astrophysics astro-ph.IM; Cosmology and Nongalactic Astrophysics astro-ph.CO; FOS Physical sciences; South Pole; South pole
• Online Access: https://dx.doi.org/10.48550/arxiv.1407.5928; https://arxiv.org/abs/1407.5928

BICEP3 is a 550 mm-aperture refracting telescope for polarimetry of radiation in the cosmic microwave background at 95 GHz. It adopts the methodology of BICEP1, BICEP2 and the Keck Array experiments - it possesses sufficient resolution to search for signatures of the inflation-induced cosmic gravitational-wave background while utilizing a compact design for ease of construction and to facilitate the characterization and mitigation of systematics. However, BICEP3 represents a significant breakthrough in per-receiver sensitivity, with a focal plane area 5$\times$ larger than a BICEP2/Keck Array receiver and faster optics ($f/1.6$ vs. $f/2.4$). Large-aperture infrared-reflective metal-mesh filters and infrared-absorptive cold alumina filters and lenses were developed and implemented for its optics. The camera consists of 1280 dual-polarization pixels; each is a pair of orthogonal antenna arrays coupled to transition-edge sensor bolometers and read out by multiplexed SQUIDs. Upon deployment at the South Pole during the 2014-15 season, BICEP3 will have survey speed comparable to Keck Array 150 GHz (2013), and will significantly enhance spectral separation of primordial B-mode power from that of possible galactic dust contamination in the BICEP2 observation patch. : 12 pages, 5 figures. Presented at SPIE Astronomical Telescopes and Instrumentation 2014: Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII. To be published in Proceedings of SPIE Volume 9153