SPARO: the submillimeter polarimeter for Antarctic remote observing

The South Pole has been identified as an excellent submillimeter site. Submillimeter continuum work at the South Pole promises to address several essential issues in astronomy including the morphology of the magnetic field in the galactic center and the search for protogalaxies. Here we will discuss the Submillimeter Polarimeter for Antarctic Remote Observing (SPARO), the first sub-kelvin cryostat designed for operation in the hostile Antarctic winter environment. We have implemented several novel design concepts, including a vapor cooled 4He cryostat and a capillary fed pumped 4He stage, in order to construct a long holdtime system with simplified operation.