C. Bischoff, A. Brizius, I. Buder, Y. Chinone, K. Cleary, R. N. Dumoulin, A. Kusaka, R. Monsalve, S. K. Naess, L. B. Newburgh, G. Nixon, R. Reeves, K. M. Smith, K. Vanderlinde, I. K. Wehus, M. Bogdan, R. Bustos, S. E. Church, R. Davis, C. Dickinson, H. K. Eriksen, T. Gaier, J. O. Gundersen, M. Hasegawa, M. Hazumi, C. Holler, K. M. Huffenberger, W. A. Imbriale, K. Ishidoshiro, M. E. Jones, P. Kangaslahti, D. J. Kapner, C. R. Lawrence, E. M. Leitch, M. Limon, J. J. McMahon, A. D. Miller, M. Nagai, H. Nguyen, T. J. Pearson, L. Piccirillo, S. J. E. Radford, A. C. S. Readhead, J. L. Richards, D. Samtleben, M. Seiffert, M. C. Shepherd, S. T. Staggs, O. Tajima, K. L. Thompson, R. Williamson, B. Winstein, E. J. Wollack, J. T. L. Zwart
The Q/U Imaging ExperimenT (QUIET) is designed to measure polarization in the Cosmic Microwave Background, targeting the imprint of inflationary gravitational waves at large angular scales ($\sim$ 1$^\circ$). Between 2008 October and 2010 December, two independent receiver arrays were deployed sequentially on a 1.4 m side-fed Dragonian telescope. The polarimeters which form the focal planes use a highly compact design based on High Electron Mobility Transistors (HEMTs) that provides simultaneous measurements of the Stokes parameters Q, U, and I in a single module. The 17-element Q-band polarimeter array, with a central frequency of 43.1 GHz, has the best sensitivity (69 $\mu\mathrm{Ks}^{1/2}$) and the lowest instrumental systematic errors ever achieved in this band, contributing to the tensor-to-scalar ratio at $r < 0.1$. The 84-element W-band polarimeter array has a sensitivity of 87 $\mu\mathrm{Ks}^{1/2}$ at a central frequency of 94.5\,GHz. It has the lowest systematic errors to date, contributing at $r < 0.01$ (QUIET Collaboration 2012) The two arrays together cover multipoles in the range $\ell \approx 25-975$. These are the largest HEMT-based arrays deployed to date. This article describes the design, calibration, performance of, and sources of systematic error for the instrument.
View original:
http://arxiv.org/abs/1207.5562
No comments:
Post a Comment