1. The POLARBEAR-2 and Simons Array Focal Plane Fabrication Status
- Author
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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, and Zahn, A
- Subjects
Physical Sciences ,Classical Physics ,Condensed Matter Physics ,CMB ,Fabrication ,Instrumentation ,Detectors ,Transition edge sensor ,Sinuous antenna ,Polarization ,Inflation ,Mathematical Physics ,General Physics ,Classical physics ,Condensed matter physics - 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.
- Published
- 2018