Characterizing the Sensitivity of 40 GHz TES Bolometers for BICEP Array
Abstract
The BICEP/Keck (BK) experiment aims to detect the imprint of primordial gravitational waves in the Cosmic Microwave Background polarization, which would be direct evidence of the inflation theory. While the tensor-to-scalar ratio has been constrained to be r_0.05 < 0.06 at 95% c.l., further improvements on this upper limit are hindered by polarized Galactic foreground emissions and removal of gravitational lensing polarization. The 30/40 GHz receiver of the BICEP Array (BA) will deploy at the end of 2019 and will constrain the synchrotron foreground with unprecedented accuracy within the BK sky patch. We will show the design of the 30/40 GHz detectors and test results summarizing its performance. The low optical and atmospheric loading at these frequencies requires our TES detectors to have low saturation power in order to be photon-noise dominated. To realize the low thermal conductivity required from a 250 mK base temperature, we developed new bolometer leg designs. We will present the relevant measured detector parameters: G, Tc, Rn, Psat , and spectral bands, and noise spectra. We achieved a per bolometer NEP including all noise components of 2.07E-17 W/sqrt(Hz), including an anticipated photon noise level 1.54E-17 W/sqrt(Hz).
Cite
@article{arxiv.2002.05219,
title = {Characterizing the Sensitivity of 40 GHz TES Bolometers for BICEP Array},
author = {C. Zhang and P. A. R. Ade and Z. Ahmed and M. Amiri and D. Barkats and R. Basu Thakur and C. A. Bischoff and J. J. Bock and H. Boenish and E. Bullock and V. Buza and J. Cheshire and J. Connors and J. Cornelison and M. Crumrine and A. Cukierman and M. Dierickx and L. Duband and S. Fatigoni and J. P. Filippini and G. Hall and M. Halpern and S. Harrison and S. Henderson and S. R. Hildebrandt and G. C. Hilton and H. Hui and K. D. Irwin and J. Kang and K. S. Karkare and E. Karpel and S. Kefeli and J. M. Kovac and C. L. Kuo and K. Lau and K. G. Megerian and L. Moncelsi and T. Namikawa and H. T. Nguyen and R. O'Brient and S. Palladino and N. Precup and T. Prouvé and C. Pryke and B. Racine and C. D. Reintsema and S. Richter and A. Schillaci and B. Schmitt and R. Schwarz and C. D. Sheehy and A. Soliman and T. St. Germaine and B. Steinbach and R. V. Sudiwala and K. L. Thompson and C. Tucker and A. D. Turner and C. Umiltà and A. G. Vieregg and A. Wandui and A. C. Weber and D. V. Wiebe and J. Willmert and W. L. K. Wu and E. Yang and K. W. Yoon and E. Young and C. Yu},
journal= {arXiv preprint arXiv:2002.05219},
year = {2020}
}
Comments
Accepted for publication in Journal of Low Temperature Physics