THE ARCADE 2 INSTRUMENT
J. Singal, Dale J. Fixsen, A. Kogut, S. Levin, M. Limon, P. M. Lubin, Paul Mirel, Michael D. Seiffert, Thyrso Villela, Edward J. Wollack, Carlos Alexandre Wuensche · The Astrophysical Journal · 2011
The second generation Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE 2) instrument is a balloon-borne experiment to measure the radiometric temperature of the cosmic microwave background and Galactic and extragalactic emission at six frequencies from 3 to 90 GHz. ARCADE 2 utilizes a double-nulled design where emission from the sky is compared to that from an external cryogenic full-aperture blackbody calibrator by cryogenic switching radiometers containing internal blackbody reference loads. In order to further minimize sources of systematic error, ARCADE 2 features a cold fully open aperture with all radiometrically active components maintained at near 2.7 K without windows or other warm objects, achieved through a novel thermal design. We discuss the design and performance of the ARCADE 2 instrument in its 2005 and 2006 flights.