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arXiv · 1807.04167

The Cosmology Large Angular Scale Surveyor Receiver Design

Jeffrey Iuliano·Joseph Eimer·Lucas Parker·Gary Rhoades·Aamir Ali·John W. Appel·Charles Bennett·Michael Brewer·Ricardo Bustos·David Chuss·Joseph Cleary·Jullianna Couto·Sumit Dahal·Kevin Denis·Rolando Dünner·Thomas Essinger-Hileman·Pedro Fluxa·Mark Halpern·Kathleen Harrington·Kyle Helson·Gene Hilton·Gary Hinshaw·Johannes Hubmayr·John Karakla·Tobias Marriage·Nathan Miller·Jeffrey John McMahon·Carolina Nuñez·Ivan Padilla·Gonzalo Palma·Matthew Petroff·Bastian Pradenas Márquez·Rodrigo Reeves·Carl Reintsema·Karwan Rostem·Deniz Augusto Nunes Valle·Trevor Van Engelhoven·Bingjie Wang·Qinan Wang·Duncan Watts·Jenet Weiland·Edward J. Wollack·Zhilei Xu·Ziang Yan·Lingzhen Zeng
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Abstract

The Cosmology Large Angular Scale Surveyor consists of four instruments performing a CMB polarization survey. Currently, the 40 GHz and first 90 GHz instruments are deployed and observing, with the second 90 GHz and a multichroic 150/220 GHz instrument to follow. The receiver is a central component of each instrument's design and functionality. This paper describes the CLASS receiver design, using the first 90 GHz receiver as a primary reference. Cryogenic cooling and filters maintain a cold, low-noise environment for the detectors. We have achieved receiver detector temperatures below 50 mK in the 40 GHz instrument for 85% of the initial 1.5 years of operation, and observed in-band efficiency that is consistent with pre-deployment estimates. At 90 GHz, less than 26% of in-band power is lost to the filters and lenses in the receiver, allowing for high optical efficiency. We discuss the mounting scheme for the filters and lenses, the alignment of the cold optics and detectors, stray light control, and magnetic shielding.

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Jeffrey Iuliano, Joseph Eimer, Lucas Parker, Gary Rhoades, Aamir Ali, John W. Appel, Charles Bennett, Michael Brewer, Ricardo Bustos, David Chuss, Joseph Cleary, Jullianna Couto, Sumit Dahal, Kevin Denis, Rolando Dünner, Thomas Essinger-Hileman, Pedro Fluxa, Mark Halpern, Kathleen Harrington, Kyle Helson, Gene Hilton, Gary Hinshaw, Johannes Hubmayr, John Karakla, Tobias Marriage, Nathan Miller, Jeffrey John McMahon, Carolina Nuñez, Ivan Padilla, Gonzalo Palma, Matthew Petroff, Bastian Pradenas Márquez, Rodrigo Reeves, Carl Reintsema, Karwan Rostem, Deniz Augusto Nunes Valle, Trevor Van Engelhoven, Bingjie Wang, Qinan Wang, Duncan Watts, Jenet Weiland, Edward J. Wollack, Zhilei Xu, Ziang Yan, Lingzhen Zeng. 2018-07-11. The Cosmology Large Angular Scale Surveyor Receiver Design. https://doi.org/10.1117/12.2312954

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