The Cosmology Large Angular Scale Surveyor (CLASS) is a polarization-sensitive telescope array located at an altitude of 5,200 m in the Chilean Atacama Desert and designed to measure the polarized Cosmic Microwave Background (CMB) over large angular scales. The CLASS array is currently observing with three telescopes covering four frequency bands: one at 40 GHz (Q); one at 90 GHz (W1); and one dichroic system at 150/220 GHz (HF). During the austral winter of 2022, we upgraded the first 90 GHz telescope (W1) by replacing four of the seven focal plane modules. These new modules contain detector wafers with an updated design, aimed at improving the optical efficiency and detector stability. We present a description of the design changes and measurements of on-sky optical efficiencies derived from observations of Jupiter.
@article{arxiv.2301.01417,
title = {On-sky performance of new 90 GHz detectors for the Cosmology Large Angular Scale Surveyor (CLASS)},
author = {Carolina Núñez and John W. Appel and Michael K. Brewer and Sarah Marie Bruno and Rahul Datta and Charles L. Bennett and Ricardo Bustos and David T. Chuss and Sumit Dahal and Kevin L. Denis and Joseph Eimer and Thomas Essinger-Hileman and Kyle Helson and Tobias Marriage and Carolina Morales Pérez and Ivan L. Padilla and Matthew A. Petroff and Karwan Rostem and Duncan J. Watts and Edward J. Wollack and Zhilei Xu},
journal= {arXiv preprint arXiv:2301.01417},
year = {2023}
}
Comments
5 pages, 3 figures, to appear in the IEEE Transactions on Applied Superconductivity. arXiv admin note: text overlap with arXiv:2208.05006