EBEX is a balloon-borne polarimeter designed to measure the intensity and polarization of the cosmic microwave background radiation. Measurements of the polarization of the CMB could probe an inflationary epoch that took place shortly after the big bang and significantly improve constraints on the values of several cosmological parameters. EBEX will also provide critical information about the level of polarized Galactic dust which will be necessary for all future CMB polarization experiments.
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EBEX consists of a 1.5 m Dragone-type telescope that provides a resolution of less than 8 arcminute over four focal planes each of 4 degree diffraction limited field of view at frequencies up to 450 GHz. Polarimetry is achieved with a magnetically levitated rotating achromatic half-wave plate. EBEX is currently in the design and construction phase, and first flight is scheduled for 2007-2008.
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