Design and performance of the multiplexed SQUID/TES array at ninety gigahertz

• Main Authors: Stanchfield, Sara, Ade, Peter, Aguirre, James, Brevik, Justus A., Cho, Hsiao-Mei, Datta, Rahul, Devlin, Mark, Dicker, Simon R., Dober, Bradley, Duff, Shannon M., Egan, Dennis, Ford, Pam, Hilton, Gene, Hubmayr, Johannes, Irwin, Kent, Knowles, Kenda, Marganian, Paul, Mason, Brian Scott, Mates, John A. B., McMahon, Jeff, Mello, Melinda, Mroczkowski, Tony, Romero, Charles, Sievers, Jonathon, Tucker, Carole, Vale, Leila R., Vissers, Michael, White, Steven, Whitehead, Mark, Ullom, Joel, Young, Alexander
• Format: Conference Object
• Language: unknown
• Published: 2018
• Subjects: South Pole; Byrd; South pole
• Online Access: https://orca.cardiff.ac.uk/id/eprint/156847/; https://ui.adsabs.harvard.edu/#abs/2018AAS.23121502S

We present the array performance and astronomical images from early science results from MUSTANG-2, a 90 GHz feedhorn-coupled, microwave SQUID-multiplexed TES bolometer array operating on the Robert C. Byrd Green Bank Telescope (GBT). MUSTANG-2 was installed on the GBT on December 2, 2016 and immediately began commissioning efforts, followed by science observations, which are expected to conclude June 2017. The feedhorn and waveguide-probe-coupled detector technology is a mature technology, which has been used on instrument including the South Pole Telescope, the Atacama Cosmology Telescope, and the Atacama B-mode Search telescope. The microwave SQUID readout system developed for MUSTANG-2 currently reads out 66 detectors with a single coaxial cable and will eventually allow thousands of detectors to be multiplexed. This microwave SQUID multiplexer combines the proven abilities of millimeterwave TES detectors with the multiplexing capabilities of KIDs with no degradation in noise performance of the detectors. Each multiplexing device is read out using warm electronics consisting of a commercially available ROACH board, a DAC/ADC card, and an Intermediate Frequency mixer circuit. The hardware was originally developed by the UC Berkeley Collaboration for Astronomy Signal Processing and Electronic Research (CASPER) group, whose primary goal is to develop scalable FPGA-based hardware with the flexibility to be used in a wide range of radio signal processing applications. MUSTANG-2 is the first on-sky instrument to use microwave SQUID multiplexing and is available as a shared-risk/PI instrument on the GBT. In MUSTANG-2's first season 7 separate proposals were awarded a total of 230 hours of telescope time.