The Balloon-Borne Large Aperture Submillimeter Telescope for Polarimetry (Blast-Pol)

The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLAST-Pol) is a suborbital mapping experiment designed to study the role of magnetic fields in star forming regions. BLAST-Pol utilizes 280 bolometric detectors to image the sky in three wavebands centered at 250, 350 and 500 µm with a 1.8 m Cassegrain telescope. BLAST-Pol was reconfigured from the BLAST telescope by the addition of linear polarization capability. The combination of high sensitivity, sub- arcminute spatial resolution, and fast mapping speed makes BLAST-Pol a crucial bridge between the large area but coarse resolution polarimetry provided by experiments such as Planck, and the high-resolution but small areas observable with ALMA. The telescope operated successfully during a 227 hr flight over Antarctica in December 2010 and again during a 300 hr flight in December 2012. This report concentrates on the instrument's performance during the 2010 and 2012 flights, both launched from the Williams Field Long Duration Balloon (LDB) facility near McMurdo Station in Antarctica, which resulted in degree-scale polarization maps of several nearby molecular clouds.