Performance and on-sky optical characterization of the SPTpol instrument

• Main Authors: George, E. M., Ade, P., Aird, K. A., Austermann, J. E., Beall, J. A., Becker, D., Bender, A., Benson, B. A., Bleem, L. E., Britton, J., Carlstrom, J. E., Chang, C. L., Chiang, H. C., Cho, H-M., Crawford, T. M., Crites, A. T., Datesman, A., de Haan, T., Dobbs, M. A., Everett, W., Ewall-Wice, A., Halverson, N. W., Harrington, N., Henning, J. W., Hilton, G. C., Holzapfel, W. L., Hoover, S., Huang, N., Hubmayr, J., Irwin, K. D., Karfunkle, M., Keisler, R., Kennedy, J., Lee, A. T., Leitch, E., Li, D., Lueker, M., Marrone, D. P., McMahon, J. J., Mehl, J., Meyer, S. S., Montgomery, J., Montroy, T. E., Nagy, J., Natoli, T., Nibarger, J. P., Niemack, M. D., Novosad, V., Padin, S., Pryke, C., Reichardt, C. L., Ruhl, J. E., Saliwanchik, B. R., Sayre, J. T., Schaffer, K. K., Shirokoff, E., Story, K., Tucker, C., Vanderlinde, K., Vieira, J. D., Wang, G., Williamson, R., Yefremenko, V., Yoon, K. W., Young, E.
• Format: Text
• Language: unknown
• Published: arXiv 2012
• Subjects: Instrumentation and Methods for Astrophysics astro-ph.IM; FOS Physical sciences; South Pole; South pole
• Online Access: https://dx.doi.org/10.48550/arxiv.1210.4971; https://arxiv.org/abs/1210.4971

In January 2012, the 10m South Pole Telescope (SPT) was equipped with a polarization-sensitive camera, SPTpol, in order to measure the polarization anisotropy of the cosmic microwave background (CMB). Measurements of the polarization of the CMB at small angular scales (~several arcminutes) can detect the gravitational lensing of the CMB by large scale structure and constrain the sum of the neutrino masses. At large angular scales (~few degrees) CMB measurements can constrain the energy scale of Inflation. SPTpol is a two-color mm-wave camera that consists of 180 polarimeters at 90 GHz and 588 polarimeters at 150 GHz, with each polarimeter consisting of a dual transition edge sensor (TES) bolometers. The full complement of 150 GHz detectors consists of 7 arrays of 84 ortho-mode transducers (OMTs) that are stripline coupled to two TES detectors per OMT, developed by the TRUCE collaboration and fabricated at NIST. Each 90 GHz pixel consists of two antenna-coupled absorbers coupled to two TES detectors, developed with Argonne National Labs. The 1536 total detectors are read out with digital frequency-domain multiplexing (DfMUX). The SPTpol deployment represents the first on-sky tests of both of these detector technologies, and is one of the first deployed instruments using DfMUX readout technology. We present the details of the design, commissioning, deployment, on-sky optical characterization and detector performance of the complete SPTpol focal plane. : 15 pages, 6 figures. Conference: SPIE Astronomical Telescopes and Instrumentation 2012