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arXiv · 2409.16440

Calibration Measurements of the BICEP3 and BICEP Array CMB Polarimeters from 2017 to 2024

Christos Giannakopoulos·Clara Vergès·P. A. R. Ade·Zeeshan Ahmed·Mandana Amiri·Denis Barkats·Ritoban Basu Thakur·Colin A. Bischoff·Dominic Beck·James J. Bock·Hans Boenish·Victor Buza·James R. Cheshire IV·Jake Connors·James Cornelison·Michael Crumrine·Ari Jozef Cukierman·Edward Denison·Marion Dierickx·Lionel Duband·Miranda Eiben·Brodi D. Elwood·Sofia Fatigoni·Jeff P. Filippini·Antonio Fortes·Min Gao·Neil Goeckner-Wald·David C. Goldfinger·James A. Grayson·Paul K. Grimes·Grantland Hall·George Halal·Mark Halpern·Emma Hand·Sam A. Harrison·Shawn Henderson·Johannes Hubmayr·Howard Hui·Kent D. Irwin·Jae Hwan Kang·Kirit S. Karkare·Sinan Kefeli·J. M. Kovac·Chao-Lin Kuo·King Lau·Margaret Lautzenhiser·Amber Lennox·Tongtian Liu·Koko G. Megerian·Oliver Miller·Lorenzo Minutolo·Lorenzo Moncelsi·Yuka Nakato·H. T. Nguyen·Roger O'brient·Anika Patel·Matthew A. Petroff·Anna R. Polish·Nathan Precup·Thomas Prouve·Clement Pryke·Carl D. Reintsema·Thibault Romand·Maria Salatino·Alessandro Schillaci·Benjamin Schmitt·Baibhav Singari·Ahmed Soliman·Tyler St Germaine·Aaron Steiger·Bryan Steinbach·Rashmi Sudiwala·Keith L. Thompson·Calvin Tsai·Carole Tucker·Anthony D. Turner·Abigail G. Vieregg·Albert Wandui·Alexis C. Weber·Justin Willmert·Wai Ling K. Wu·Hung-I Yang·Cyndia Yu·Lingzhen Zeng·Cheng Zhang·Silvia Zhang
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Abstract

The BICEP3 and BICEP Array polarimeters are small-aperture refracting telescopes located at the South Pole designed to measure primordial gravitational wave signatures in the Cosmic Microwave Background (CMB) polarization, predicted by inflation. Constraining the inflationary signal requires not only excellent sensitivity, but also careful control of instrumental systematics. Both instruments use antenna-coupled orthogonally polarized detector pairs, and the polarized sky signal is reconstructed by taking the difference in each detector pair. As a result, the differential response between detectors within a pair becomes an important systematic effect we must control. Additionally, mapping the intensity and polarization response in regions away from the main beam can inform how sidelobe levels affect CMB measurements. Extensive calibration measurements are taken in situ every austral summer for control of instrumental systematics and instrument characterisation. In this work, we detail the set of beam calibration measurements that we conduct on the BICEP receivers, from deep measurements of main beam response to polarized beam response and sidelobe mapping. We discuss the impact of these measurements for instrumental systematics studies and design choices for future CMB receivers.

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Christos Giannakopoulos, Clara Vergès, P. A. R. Ade, Zeeshan Ahmed, Mandana Amiri, Denis Barkats, Ritoban Basu Thakur, Colin A. Bischoff, Dominic Beck, James J. Bock, Hans Boenish, Victor Buza, James R. Cheshire IV, Jake Connors, James Cornelison, Michael Crumrine, Ari Jozef Cukierman, Edward Denison, Marion Dierickx, Lionel Duband, Miranda Eiben, Brodi D. Elwood, Sofia Fatigoni, Jeff P. Filippini, Antonio Fortes, Min Gao, Neil Goeckner-Wald, David C. Goldfinger, James A. Grayson, Paul K. Grimes, Grantland Hall, George Halal, Mark Halpern, Emma Hand, Sam A. Harrison, Shawn Henderson, Johannes Hubmayr, Howard Hui, Kent D. Irwin, Jae Hwan Kang, Kirit S. Karkare, Sinan Kefeli, J. M. Kovac, Chao-Lin Kuo, King Lau, Margaret Lautzenhiser, Amber Lennox, Tongtian Liu, Koko G. Megerian, Oliver Miller, Lorenzo Minutolo, Lorenzo Moncelsi, Yuka Nakato, H. T. Nguyen, Roger O'brient, Anika Patel, Matthew A. Petroff, Anna R. Polish, Nathan Precup, Thomas Prouve, Clement Pryke, Carl D. Reintsema, Thibault Romand, Maria Salatino, Alessandro Schillaci, Benjamin Schmitt, Baibhav Singari, Ahmed Soliman, Tyler St Germaine, Aaron Steiger, Bryan Steinbach, Rashmi Sudiwala, Keith L. Thompson, Calvin Tsai, Carole Tucker, Anthony D. Turner, Abigail G. Vieregg, Albert Wandui, Alexis C. Weber, Justin Willmert, Wai Ling K. Wu, Hung-I Yang, Cyndia Yu, Lingzhen Zeng, Cheng Zhang, Silvia Zhang. 2024-09-24. Calibration Measurements of the BICEP3 and BICEP Array CMB Polarimeters from 2017 to 2024. https://arxiv.org/abs/2409.16440

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