Measurement of the polarization of the cosmic microwave background

[摘要] Measurement of cosmic microwave background (CMB) polarization will provide a powerful check on the model that describes CMB ΔT fluctuations as arising fromdensity fluctuations in the early universe, break degeneracies between cosmological parameters that arise in interpreting ΔT fluctuations, and may ultimately allow detection of the stochastic gravity-wave background predicted by inflationary models. We describe the development and laboratory characterization of a bolometric experiment designed to measure the arcminute-scale polarization of the CMB. The Polatron receiver will be mounted at the Cassegrain focus of the 5.5 m telescope at the Owens Valley Radio Observatory. The receiver will measure both the Q and U Stokes parameters over a 20% pass-band centered near 100 GHz, with the input polarizationsignal modulated at ~ 1 Hz by a rotating, birefringent, quartz half-wave plate. In six months of observation we plan to observe ~ 400 2.5 arcminute pixels in a ringabout the North Celestial Pole to a precision of ~ 5 µK per pixel in each of Q and U, adequate to unambiguously detect CMB polarization at levels predicted by current models.

[发布机构] University:California Institute of Technology;Department:Physics, Mathematics and Astronomy

[关键词] Physics