South Pole Telescope - The SPTpol Camera

The SPTpol Camera

The camera currently installed on the SPT–also designed with superconducting TES arrays–is even more sensitive than the SPT-SZ camera and, crucially, has the ability to measure the polarization of the incoming light (hence the name SPTpol - South Pole Telescope POLarimeter). The 780 polarization-sensitive pixels (each with two separate TES bolometers, one sensitive to each linear polarization) are divided between observing frequencies of 90 GHz and 150 GHz, and pixels at the two frequencies are designed with different detector architectures. The 150 GHz pixels are corrugated-feedhorn-coupled TES polarimeters fabricated in monolithic arrays at the National Institute of Standards and Technology. The 90 GHz pixels are individually packaged dual-polarization absorber-coupled polarimeters developed at Argonne National Laboratory. The 90 GHz pixels are coupled to the telescope optics through individually machined contoured feedhorns.