The Advanced Atacama Cosmology Telescope Polarimeter (AdvACT) \cite{thornton} is an upgrade for the Atacama Cosmology Telescope using Transition Edge Sensor (TES) detector arrays to measure cosmic microwave background (CMB) temperature and polarization anisotropies in multiple frequencies. The low frequency (LF) array was deployed early 2020. It consists of 292 TES bolometers observing in two bands centered at 27 GHz and 39 GHz. At these frequencies, it is sensitive to synchrotron radiation from our galaxy as well as to the CMB, and complements the AdvACT arrays operating at 90, 150 and 230 GHz. We present the initial LF array on-site characterization, including the time constant, optical efficiency and array sensitivity.
@article{arxiv.2101.02658,
title = {In situ Performance of the Low Frequency Arrayfor Advanced ACTPol},
author = {Yaqiong Li and Jason E. Austermann and James A. Beall and Sarah Marie Bruno and Steve K. Choi and Nicholas F. Cothard and Kevin T. Crowley and Shannon M. Duff and Shuay-Pwu Patty Ho and Joseph E. Golec and Gene C. Hilton and Matthew Hasselfield and Johannes Hubmay and Brian J. Koopman and Marius Lungu and Jeff McMahon and Michael D. Niemack and LymanA. Page and Maria Salatino and Sara M. Simon and Suzanne T. Staggs and Jason R. Stevens and Joel N. Ullom and Eve M. Vavagiakis and Yuhan Wang and Edward J. Wollack and Zhilei Xu},
journal= {arXiv preprint arXiv:2101.02658},
year = {2021}
}