Texte integral disponible sur http://proc.sf2a.asso.fr/sf2a06.phpInternational audienceThe detection and characterisation of Cosmic Microwave Background B-mode polarization is one of the next challenges in observational cosmology. This primordial polarization mode is only due to tensor perturbations of the metric produced by primordial gravitational waves, which could have been generated during the inflation epoch. With a signal of less than 0.1? K, B-mode measurement requires very sensitive experiments and also an extremely good control of instrumental effects. In this paper we present the BRAIN experiment, a bolometric interferometer devoted to B-mode detection. This new detection architecture allows to directly measure the Fourier modes of the Stokes parameters. High sensitivity is obtained by using low temperature bolometers while systematic effects are reduced by using the interferometric technique
