Description
Summary:The rotational component of the CMB polarization, the so-called B-modes, is one of the major topic for next generation CMB experiments. This signal traces the effect on the CMB due to primordial gravitational waves produced during the inflationary epoch, probing the physics of the very early universe at GUT energy scales. This is a challenge, being the expected amplitude of B-mode polarization ∼ 0.1μK. In this paper we describe the BRAIN experiment, a bolometric interferometer which combines high-sensitivity bolometric detectors with the excellent control of systematic effects proper of interferometers. Being a ground based experiment, we identified Dome Charlie in Antarctica as the best site for such measurements. In order to validate the goodness of the site, as well as some of the implemented technical solutions, we built a pathfinder experiment which has been successfully operated during last Antarctic summer, and we report about preliminary results obtained. © 2008 World Scientific Publishing Co. Pte. Ltd.