Feedhorn-coupled TES polarimeter camera modules at 150 GHz for CMB polarization measurements with SPTpol
Abstract
The SPTpol camera is a dichroic polarimetric receiver at 90 and 150 GHz. Deployed in January 2012 on the South Pole Telescope (SPT), SPTpol is looking for faint polarization signals in the Cosmic Microwave Background (CMB). The camera consists of 180 individual Transition Edge Sensor (TES) polarimeters at 90 GHz and seven 84-polarimeter camera modules (a total of 588 polarimeters) at 150 GHz. We present the design, dark characterization, and in-lab optical properties of the 150 GHz camera modules. The modules consist of photolithographed arrays of TES polarimeters coupled to silicon platelet arrays of corrugated feedhorns, both of which are fabricated at NIST-Boulder. In addition to mounting hardware and RF shielding, each module also contains a set of passive readout electronics for digital frequency-domain multiplexing. A single module, therefore, is fully functional as a miniature focal plane and can be tested independently. Across the modules tested before deployment, the detectors average a critical temperature of 478 mK, normal resistance R_N of 1.2 Ohm, unloaded saturation power of 22.5 pW, (detector-only) optical efficiency of ~ 90%, and have electrothermal time constants < 1 ms in transition.
Cite
@article{arxiv.1210.4969,
title = {Feedhorn-coupled TES polarimeter camera modules at 150 GHz for CMB polarization measurements with SPTpol},
author = {J. W. Henning and P. Ade and K. A. Aird and J. E. Austermann and J. A. Beall and D. Becker and B. A. Benson and L. E. Bleem and J. Britton and J. E. Carlstrom and C. L. Chang and H. -M. Cho and T. M. Crawford and A. T. Crites and A. Datesman and T. de Haan and M A. Dobbs and W. Everett and A. Ewall-Wice and E. M. George and N. W. Halverson and N. Harrington and G. C. Hilton and W. L. Holzapfel and J. Hubmayr and K. D. Irwin and M. Karfunkle and R. Keisler and J. Kennedy and A. T. Lee and E. Leitch and D. Li and M. Lueker and D. P. Marrone and J. J. McMahon and J. Mehl and S. S. Meyer and J. Montgomery and T. E. Montroy and J. Nagy and T. Natoli and J. P. Nibarger and M. D. Niemack and V. Novosad and S. Padin and C. Pryke and C. L. Reichardt and J. E. Ruhl and B. R. Saliwanchik and J. T. Sayre and K. K. Schaffer and E. Shirokoff and K. Story and C. Tucker and K. Vanderlinde and J. D. Vieira and G. Wang and R. Williamson and V. Yefremenko and K. W. Yoon and E. Young},
journal= {arXiv preprint arXiv:1210.4969},
year = {2012}
}
Comments
15 pages, 11 figures