Wed, Jan 4, 2012, 11:00 am to 12:00 pm
Zigmund Kermish, UC Berkeley Abstract:We present the design and characterization of the POLARBEAR experiment. POLARBEAR will measure the B-mode polarization of the cosmic microwave background (CMB) on angular scales ranging from the experiment’s 4’ beam size to several degrees. The experiment utilizes a unique focal plane of1,274 antenna-coupled, polarization sensitive transition-edge sensor(TES) bolometers cooled to 250 milli-Kelvin. Employing this focal plane along with stringent control over systematic errors, POLARBEAR is designed to detect the expected small scale signal due to gravitational lensing and search for the large scale signal from inflationary gravitational waves. POLARBEAR was assembled for an engineering run in the Inyo Mountains of California in 2010 and is currently being deployed to the Atacama Desert in Chile. An overview of the instrument is presented along with characterization results from the California engineering run and the status of the Chilean deployment.