QUBIC: The QU Bolometric Interferometer for Cosmology
The QUBIC collaboration, E. Battistelli, A. Baù, D. Bennett, L. Bergé, J. -Ph. Bernard, P. de Bernardis, A. Bounab, É. Bréelle, E. F. Bunn, M. Calvo, R. Charlas… 展开作者
The QUBIC collaboration, E. Battistelli, A. Baù, D. Bennett, L. Bergé, J. -Ph. Bernard, P. de Bernardis, A. Bounab, É. Bréelle, E. F. Bunn, M. Calvo, R. Charlassier, S. Collin, A. Cruciani, G. Curran, L. Dumoulin, A. Gault, M. Gervasi, A. Ghribi, M. Giard, C. Giordano, Y. Giraud-Héraud, M. Gradziel, L. Guglielmi, J. -Ch. Hamilton, V. Haynes, J. Kaplan, A. Korotkov, J. Landé, B. Maffei, M. Maiello, S. Malu, S. Marnieros, S. Masi, A. Murphy, F. Nati, C. O'Sullivan, F. Pajot, A. Passerini, S. Peterzen, F. Piacentini, M. Piat, L. Piccirillo, G. Pisano, G. Polenta, D. Prêle, D. Romano, C. Rosset, M. Salatino, A. Schillacci, G. Sironi, R. Sordini, S. Spinelli, A. Tartari, P. Timbie, G. Tucker, L. Vibert, F. Voisin, R. A. Watson, M. Zannoni
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12 pages, 10 figures, submitted to Astronomy and Astrophysics
One of the major challenges of modern cosmology is the detection of B-mode polarization anisotropies in the CMB. These originate from tensor fluctuations of the metric produced during the inflationary phase. Their detection would therefore constitute a major step towards understanding the primordial Universe. The expected level of these anisotropies is however so small that it requires a new generation of instruments with high sensitivity and extremely good control of systematic effects. We propose the QUBIC instrument based on the novel concept of bolometric interferometry, bringing together the sensitivity advantages of bolometric detectors with the systematics effects advantages of interferometry. Methods: The instrument will directly observe the sky through an array of entry horns whose signals will be combined together using an optical combiner. The whole set-up is located inside a cryostat. Polarization modulation will be achieved using a rotating half-wave plate and interference fringes will be imaged on two focal planes (separated by a polarizing grid) tiled with bolometers. We show that QUBIC can be considered as a synthetic imager, exactly similar to a usual imager but with a synthesized beam formed by the array of entry horns. Scanning the sky provides an additional modulation of the signal and improve the sky coverage shape. The usual techniques of map-making and power spectrum estimation can then be applied. We show that the sensitivity of such an instrument is comparable with that of an imager with the same number of horns. We anticipate a low level of beam-related systematics thanks to the fact that the synthesized beam is determined by the location of the primary horns. Other systematics should be under good control thanks to an autocalibration technique, specific to our concept, that will permit the accurate determination of most of the systematics parameters.
QUBIC: using NbSi TESs with a bolometric interferometer to characterize the polarisation of the CMB
QUBIC（Q \& U Bolometric Interferometer for Cosmology）是一个国际地面实验，专门用于测量宇宙微波背景（CMB）的偏振起伏。它是基于测热干涉测量，一个原始的检测技术相结合的免疫系统的影响与低温非相干探测器的灵敏度的干涉仪。QUBIC将部署在阿根廷萨尔塔省San Antonio de los Cobres附近的Alto Chorrillos山区。QUBIC检测链由2048个冷却至350 mK的NbSi跃迁边缘传感器（TES）组成。电压偏置的TES通过基于1 K超导量子干涉器件（SQUID）和60 K新型SiGe专用集成电路（ASIC）的时域多路复用读取，从而实现前所未有的复用（MUX）因子128。QUBIC实验目前正在实验室中进行表征，在升级到完整仪器之前，减少了探测器的数量。我将介绍这个表征阶段的最后结果，重点是探测器和读出系统。
