A Ground-Based 200/350 Micrometer Polarization-Sensitive Photometer

We describe a concept for a polarization-sensitive photometer for use at the South Pole and Atacama that employs Transition-Edge Sensor (TES) detectors. We will use two 8x8 element array architecture originally developed at NASA Goddard for a 3 mm camera.for the Green Bank Telescope. The elements will be tuned to have absorption peaks in both the 200 and 350 micron atmospheric windows. This instrument will provide a testbed for three major issues confronting a future far-infrared polarimeter for SOFIA. The first is the TES detector technology. The second is a polarization modulator that can be quickly reconfigured for different passbands. The third is the ability to optimize polarimetric and photometric detection capabilities in the same instrument. Scientifically, this instrument will explore the emission from Galactic star-forming regions in two spectral bands, giving valuable information concerning their spectral energy distributions. Polarimetrically, this instrument will allow coverage of the polarization spectrum for bright Galactic sources, giving new insights into dust grain physics.