| We describe the design and performance of the BOOMERANG experiment, and report on measurements of the temperature and polarization anisotropies of the Cosmic Microwave Background (CMB) obtained during the January 2003 flight of BOOMERANG (B2K). To enable these studies, we have developed a bolometric detector which is intrinsically sensitive to linear polarization. The receiver consists of a pair of colocated silicon nitride micromesh absorbers that couple anisotropically to linearly polarized radiation through a corrugated waveguide structure. This system allows simultaneous background limited measurements of the Stokes I and Q parameters over ∼30% bandwidths at frequencies from ∼60 to 400 GHz.; The science results reported here are derived from 195 hours of observation with four 145 GHz Polarization Sensitive Bolometer (PSB) pairs [83]. The data include 75 hours of observations distributed over 1.8% of the sky with an additional 120 hours concentrated on the central portion of the field, itself representing 0.22% of the full sky. The B2K data improve significantly on existing measurements of the CMB temperature power spectrum at angular scales of 500 ≲ ℓ ≲ 1100. In addition, we have measured a spectrum of curl-free polarization anisotropies that, in the context of the most simple adiabatic inflationary models, are consistent with the predictions of the currently favored ΛCDM cosmology. |
