University of Chicago
Astronomy & Astrophysics
Supporting Stations: South Pole Station
Research Locations: MAPO (Martin A. Pomerantz Observatory)
The Cosmic Gravitational-wave Background (CGB) imprints a signature in the polarization of the Cosmic Microwave Background (CMB). Detecting that signature is arguably the most important goal in cosmology today. BICEP is the first CMB polarimeter specifically designed to search for the signature of the CGB. Since 2006, BICEP has mapped about 2% of the sky that is uniquely free of galactic confusion. SPUD ( Pryke A-149-S, aka "The Keck Array") is an array of receivers similar to BICEP2 and together they provide a further increase in mapping speed and the possibility of multiple frequencies. These receivers are more compact, use pulse tube cryogenic refrigerators rather than liquid helium, and share the former DASI mount near MAPO. This work comprises two projects: Clem Pryke’s SPUD/Keck Array component (A-149), and John Kovac’s BICEP2 component (A-039).
Field Season Overview:
SPUD was installed in the 2010-11 season comprising three preliminary receivers operated at 150GHz through winter 2011. In 2011-12 the receivers were reconfigured and two more were added (also at 150GHz). This array of five is currently observing. This season 14 participants will perform season-ending calibrations using the far field flat mirror and several calibration sources mounted on the DSL mast. At the end of November the existing receivers will be taken down for service and upgrade. During December the receivers will be over-hauled. The new 100GHz receiver, focal planes and component detector tiles will be assembled and tested. One of the existing ones will be reconfigured with all new optics for operation at 100GHz. The other three existing receivers will have their focal planes removed and replacements for some of their detector tiles will be installed in the "tent" cleanroom in DSL. As each receiver's re-work is completed it will be reassembled, cooled and subjected to the usual battery of lab tests including optical efficiency and near field beam mapping. Once proven it will be re-installed on the telescope mount.
Deploying Team Members:
John Kovac (Co-PI)
Clement Pryke (PI)