The POLARBEAR CMB Polarization Experiment

The CMB polarization is one of the few tools we know of to probe physics at inflationary energy scales, where grand unified theories may manifest themselves. High sensitivity polarization anisotropy maps of the CMB have the potential to reveal the signature of inflationary gravity waves, generally regarded as the "smoking gun" of inflation.

POLARBEAR is a ground based 4m off-axis Gregorian telescope that will be sited on the Atacama Plateau in Chile. The focal plane houses ~1000 polarization sensitive antenna coupled TES detectors read out with the Digital Frequency Domain Multiplexer.

The POLARBEAR experiment is being built in collaboration with UC Berkeley (lead institution, PI Adrian Lee), LBNL, UC San Diego, UC Colorado, Imperial College London, Cardiff U., and APC Paris-7. The McGill team consists of Prof. Matt Dobbs and postdoc Peter Hyland.

(An array of antenna-coupled bolometers developed at UC Berkeley (above left), model of the POLARBEAR Telescope (right))
(3D model of the POLARBEAR cryostat (top) and its realization (bottom))