The Keck Array: a pulse tube cooled CMB polarimeter
The Keck Array is a cosmic microwave background (CMB) polarimeter that will begin observing from the South Pole in late 2010. The initial deployment will consist of three telescopes similar to BICEP2 housed in ultracompact, pulse tube cooled cryostats. Two more receivers will be added the following year. In these proceedings we report on the design and performance of the Keck cryostat. We also report some initial results on the performance of antenna-coupled TES detectors operating in the presence of a pulse tube. We find that the performance of the detectors is not seriously impacted by the replacement of BICEP2's liquid helium cryostat with a pulse tube cooled cryostat.
Additional Information© 2010 SPIE. The International Society for Optical Engineering. The Keck-Array is funded by the National Science Foundation through grants ANT-0742592 and ANT-0742818 and by the Keck Foundation. We acknowledge assistance from the KICP at the University of Chicago through the grant NSF PHY-0114422, and the support of the NASA Postdoctoral Program for Zak Staniszewski. This paper is dedicated to the memory of Andrew Lange, who died under tragic circumstances in January 2010. Andrew made invaluable contributions to the field of experimental cosmology. He played a central role in the conception of the BICEP2 and Keck experiments. His scientific aptitude, leadership, and unique abilities to recognize and develop young scientists are sorely missed by his friends and colleagues.
Published - 77411R_1.pdf
Submitted - 1104.5516v1.pdf