학술논문
The POLARBEAR-2 and Simons Array Focal Plane Fabrication Status
Document Type
article
Author
Westbrook, B; Ade, PAR; Aguilar, M; Akiba, Y; Arnold, K; Baccigalupi, C; Barron, D; Beck, D; Beckman, S; Bender, AN; Bianchini, F; Boettger, D; Borrill, J; Chapman, S; Chinone, Y; Coppi, G; Crowley, K; Cukierman, A; de Haan, T; Dünner, R; Dobbs, M; Elleflot, T; Errard, J; Fabbian, G; Feeney, SM; Feng, C; Fuller, G; Galitzki, N; Gilbert, A; Goeckner-Wald, N; Groh, J; Halverson, NW; Hamada, T; Hasegawa, M; Hazumi, M; Hill, CA; Holzapfel, W; Howe, L; Inoue, Y; Jaehnig, G; Jaffe, A; Jeong, O; Kaneko, D; Katayama, N; Keating, B; Keskitalo, R; Kisner, T; Krachmalnicoff, N; Kusaka, A; Le Jeune, M; Lee, AT; Leon, D; Linder, E; Lowry, L; Madurowicz, A; Mak, D; Matsuda, F; May, A; Miller, NJ; Minami, Y; Montgomery, J; Navaroli, M; Nishino, H; Peloton, J; Pham, A; Piccirillo, L; Plambeck, D; Poletti, D; Puglisi, G; Raum, C; Rebeiz, G; Reichardt, CL; Richards, PL; Roberts, H; Ross, C; Rotermund, KM; Segawa, Y; Sherwin, B; Silva-Feaver, M; Siritanasak, P; Stompor, R; Suzuki, A; Tajima, O; Takakura, S; Takatori, S; Tanabe, D; Tat, R; Teply, GP; Tikhomirov, A; Tomaru, T; Tsai, C; Whitehorn, N; Zahn, A
Source
Journal of Low Temperature Physics. 193(5-6)
Subject
Language
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 Simons Array, which is an array of three cosmic microwave background polarization-sensitive telescopes located at the POLARBEAR 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 dichroic optical pixels, each of which has 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) uses a silicon oxide (SiOx) for the transmission lines and crossover process for orthogonal polarizations. The second we call Version 13 (V13) 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±0.20Ω, and saturation 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±0.2Ω, and saturation powers of 10.8 ± 1.8 pW and 22.9 ± 2.6 pW for the 90 and 150 GHz bands, respectively. Production and characterization of arrays for PB2-B are ongoing and are expected to be completed by the summer of 2018. We have fabricated the first three candidate arrays for PB2-C but do not have any characterization results to present at this time.