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arXiv · 1907.10947

On-sky performance of the SPT-3G frequency-domain multiplexed readout

A. N. Bender·A. J. Anderson·J. S. Avva·P. A. R. Ade·Z. Ahmed·P. S. Barry·R. Basu Thakur·B. A. Benson·L. Bryant·K. Byrum·J. E. Carlstrom·F. W. Carter·T. W. Cecil·C. L. Chang·H. -M. Cho·J. F. Cliche·A. Cukierman·T. de Haan·E. V. Denison·J. Ding·M. A. Dobbs·D. Dutcher·W. Everett·K. R. Ferguson·A. Foster·J. Fu·J. Gallicchio·A. E. Gambrel·R. W. Gardner·A. Gilbert·J. C. Groh·S. Guns·R. Guyser·N. W. Halverson·A. H. Harke-Hosemann·N. L. Harrington·J. W. Henning·G. C. Hilton·W. L. Holzapfel·D. Howe·N. Huang·K. D. Irwin·O. B. Jeong·M. Jonas·A. Jones·T. S. Khaire·A. M. Kofman·M. Korman·D. L. Kubik·S. Kuhlmann·C. -L. Kuo·A. T. Lee·E. M. Leitch·A. E. Lowitz·S. S. Meyer·D. Michalik·J. Montgomery·A. Nadolski·T. Natoli·H. Nguyen·G. I. Noble·V. Novosad·S. Padin·Z. Pan·P. Paschos·J. Pearson·C. M. Posada·W. Quan·A. Rahlin·D. Riebel·J. E. Ruhl·J. T. Sayre·E. Shirokoff·G. Smecher·J. A. Sobrin·A. A. Stark·J. Stephen·K. T. Story·A. Suzuki·K. L. Thompson·C. Tucker·L. R. Vale·K. Vanderlinde·J. D. Vieira·G. Wang·N. Whitehorn·V. Yefremenko·K. W. Yoon·M. R. Young
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Abstract

Frequency-domain multiplexing (fMux) is an established technique for the readout of large arrays of transition edge sensor (TES) bolometers. Each TES in a multiplexing module has a unique AC voltage bias that is selected by a resonant filter. This scheme enables the operation and readout of multiple bolometers on a single pair of wires, reducing thermal loading onto sub-Kelvin stages. The current receiver on the South Pole Telescope, SPT-3G, uses a 68x fMux system to operate its large-format camera of $\sim$16,000 TES bolometers. We present here the successful implementation and performance of the SPT-3G readout as measured on-sky. Characterization of the noise reveals a median pair-differenced 1/f knee frequency of 33 mHz, indicating that low-frequency noise in the readout will not limit SPT-3G's measurements of sky power on large angular scales. Measurements also show that the median readout white noise level in each of the SPT-3G observing bands is below the expectation for photon noise, demonstrating that SPT-3G is operating in the photon-noise-dominated regime.

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A. N. Bender, A. J. Anderson, J. S. Avva, P. A. R. Ade, Z. Ahmed, P. S. Barry, R. Basu Thakur, B. A. Benson, L. Bryant, K. Byrum, J. E. Carlstrom, F. W. Carter, T. W. Cecil, C. L. Chang, H. -M. Cho, J. F. Cliche, A. Cukierman, T. de Haan, E. V. Denison, J. Ding, M. A. Dobbs, D. Dutcher, W. Everett, K. R. Ferguson, A. Foster, J. Fu, J. Gallicchio, A. E. Gambrel, R. W. Gardner, A. Gilbert, J. C. Groh, S. Guns, R. Guyser, N. W. Halverson, A. H. Harke-Hosemann, N. L. Harrington, J. W. Henning, G. C. Hilton, W. L. Holzapfel, D. Howe, N. Huang, K. D. Irwin, O. B. Jeong, M. Jonas, A. Jones, T. S. Khaire, A. M. Kofman, M. Korman, D. L. Kubik, S. Kuhlmann, C. -L. Kuo, A. T. Lee, E. M. Leitch, A. E. Lowitz, S. S. Meyer, D. Michalik, J. Montgomery, A. Nadolski, T. Natoli, H. Nguyen, G. I. Noble, V. Novosad, S. Padin, Z. Pan, P. Paschos, J. Pearson, C. M. Posada, W. Quan, A. Rahlin, D. Riebel, J. E. Ruhl, J. T. Sayre, E. Shirokoff, G. Smecher, J. A. Sobrin, A. A. Stark, J. Stephen, K. T. Story, A. Suzuki, K. L. Thompson, C. Tucker, L. R. Vale, K. Vanderlinde, J. D. Vieira, G. Wang, N. Whitehorn, V. Yefremenko, K. W. Yoon, M. R. Young. 2019-07-25. On-sky performance of the SPT-3G frequency-domain multiplexed readout. https://doi.org/10.1007/s10909-019-02280-w

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