Deployment of POLARBEAR-2b

Journal Article · 11 May 2024 · Journal of Low Temperature Physics

DOI: https://doi.org/10.1007/s10909-024-03127-9 · OSTI ID:2406024

Russell, Megan ^[1]; Sakaguri, Kana ^[2]; Lowry, Lindsay Ng ^[3]; Adkins, Tylor ^[3]; Arnold, Kam ^[1]; Baccigalupi, Carlo ^[4]; Crowley, Kevin T. ^[1]; Elleflot, Tucker ^[5]; Farias, Nicole ^[3]; Hazumi, Masashi ^[6]; Ito, Jennifer ^[7]; Jeong, Oliver ^[3]; Lee, Adrian ^[8]; Lew, Michael ^[7]; Nelson, Jacob ^[7]; Siritanasak, Praween ^[9]; Tsan, Tran ^[1]

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1. Univ. of California, San Diego, CA (United States)
2. Univ. of Tokyo (Japan)
3. University of California, Berkeley, CA (United States)
4. International School for Advanced Studies (SISSA), Trieste (Italy); Institute for Fundamental Physics of the Universe (IFPU), Grignano (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Trieste (Italy)
5. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
6. High Energy Accelerator Research Organization (KEK), Tsukuba (Japan)
7. Westmont College, Santa Barbara, CA (United States)
8. University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
9. National Astronomical Research Institute of Thailand (Thailand)

POLARBEAR-2b (PB-2b) is the second receiver in the Simons Array, a cosmic microwave background (CMB) polarization experiment. The Simons Array uses dichroic polarization sensitive lenslet-coupled sinuous antennas and transition-edge sensor (TES) bolometers made of superconducting films. These bolometers are read out with frequency multiplexing electronics. PB-2b contains ~7500 detectors in two bands at 90 and 150 GHz with arcminute resolution. The polarization of these detectors is modulated by a cryogenic continuously rotating half-wave plate. PB-2b was installed on its telescope in 2022 in the Atacama Desert at an altitude of 5.2 km. This paper will detail initial readout commissioning, test of a new loopgain monitoring method, and focusing the optics. Work is ongoing to commission the remaining ambient temperature readout electronics, measure detector time constants, and observe with the cryogenic half-wave plate spinning.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Contributing Organization: POLARBEAR Collaboration
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 2406024
• Journal Information: Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 1-2 Vol. 216; ISSN 0022-2291
• Publisher: Springer NatureCopyright Statement
• Country of Publication: United States
• Language: English