The POLARBEAR-2 and Simons Array Focal Plane Fabrication Status
Abstract
We present on the status of POLARBEAR-2 A (PB2-A) focal plane fabrication. The PB2-A is the first of three telescopes in the Simon Array (SA), which is an array of three cosmic microwave background (CMB) polarization sensitive telescopes located at the POLARBEAR (PB) site in Northern Chile. As the successor to the PB experiment, each telescope and receiver combination is named as PB2-A, PB2-B, and PB2-C. PB2-A and -B will have nearly identical receivers operating at 90 and 150 GHz while PB2-C will house a receiver operating at 220 and 270 GHz. Each receiver contains a focal plane consisting of seven close-hex packed lenslet coupled sinuous antenna transition edge sensor bolometer arrays. Each array contains 271 di-chroic optical pixels each of which have four TES bolometers for a total of 7588 detectors per receiver. We have produced a set of two types of candidate arrays for PB2-A. The first we call Version 11 (V11) and uses a silicon oxide (SiOx) for the transmission lines and cross-over process for orthogonal polarizations. The second we call Version 13 (V13) and uses silicon nitride (SiNx) for the transmission lines and cross-under process for orthogonal polarizations. We have produced enough of each type of array to fully populate the focal plane of the PB2-A receiver. The average wirebond yield for V11 and V13 arrays is 93.2% and 95.6% respectively. The V11 arrays had a superconducting transition temperature (Tc) of 452 +/- 15 mK, a normal resistance (Rn) of 1.25 +/- 0.20 Ohms, and saturations powers of 5.2 +/- 1.0 pW and 13 +/- 1.2 pW for the 90 and 150 GHz bands respectively. The V13 arrays had a superconducting transition temperature (Tc) of 456 +/-6 mK, a normal resistance (Rn) of 1.1 +/- 0.2 Ohms, and saturations powers of 10.8 +/- 1.8 pW and 22.9 +/- 2.6 pW for the 90 and 150 GHz bands respectively.
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Cite
@article{arxiv.2210.04117,
title = {The POLARBEAR-2 and Simons Array Focal Plane Fabrication Status},
author = {B. Westbrook and P. A. R. Ade and M. Aguilar and Y. Akiba and K. Arnold and C. Baccigalupi and D. Barron and D. Beck and S. Beckman and A. N. Bender and F. Bianchini and D. Boettger and J. Borrill and S. Chapman and Y. Chinone and G. Coppi and K. Crowley and A. Cukierman and T. de and R. Dünner and M. Dobbs and T. Elleflot and J. Errard and G. Fabbian and S. M. Feeney and C. Feng and G. Fuller and N. Galitzki and A. Gilbert and N. Goeckner-Wald and J. Groh and N. W. Halverson and T. Hamada and M. Hasegawa and M. Hazumi and C. A. Hill and W. Holzapfel and L. Howe and Y. Inoue and G. Jaehnig and A. Jaffe and O. Jeong and D. Kaneko and N. Katayama and B. Keating and R. Keskitalo and T. Kisner and N. Krachmalnicoff and A. Kusaka and M. Le and A. T. Lee and D. Leon and E. Linder and L. Lowry and A. Madurowicz and D. Mak and F. Matsuda and A. May and N. J. Miller and Y. Minami and J. Montgomery and M. Navaroli and H. Nishino and J. Peloton and A. Pham and L. Piccirillo and D. Plambeck and D. Poletti and G. Puglisi and C. Raum and G. Rebeiz and C. L. Reichardt and P. L. Richards and H. Roberts and C. Ross and K. M. Rotermund and Y. Segawa and B. Sherwin and M. Silva-Feaver and P. Siritanasak and R. Stompor and A. Suzuki and O. Tajima and S. Takakura and S. Takatori and D. Tanabe and R. Tat and G. P. Teply and A. Tikhomirov and T. Tomaru and C. Tsai and N. Whitehorn and A. Zahn},
journal= {arXiv preprint arXiv:2210.04117},
year = {2022}
}