BICEP1 is a small aperture refractive telescope which provides an instantaneous field of view of 17 degrees with an angular resolution of 55' and 37' at 100 GHz and 150 GHz respectively. 49 pairs of polarization-sensitive bolometers are cooled to 250 mK using a He4/He3 sorption fridge, and are coupled to incoming radiation via corrugated feed horns. The refractive optics are cooled to 4K to minimize loading and systematics.

Left: Cutaway view of the BICEP1 cryostat with optics shown. Right: The 4K insert surrounds the 250mK focal plane. For simplicity only one pixel's horn is shown.

Left: The fully assembled focal plane. Right: The measured beams.

From 2006-2008, BICEP1 observed a ~1000 square degree region which is expected to have low foreground contamination. BICEP1 has provided the best upper limit on r derived from a search for B-mode polarization: r<0.70 at 95% CL (Barkats et al. 2014).

This material is based upon work supported by the National Science Foundation.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s)
and do not necessarily reflect the views of the National Science Foundation.
NSF logo USAP logo