Foregrounds contamination in CMB polarization data: implications for CMB B-mode polarization measurements with Planck

We analyze the possibility of detection of the Cosmic Microwave Background (CMB) B-mode polarization by the Planck experiment for the ACDM cosmological model with tensor contribution to primordial perturbation given by currently favored ratio of tensor to scalar perturbations, 0.016 < r < 0.16. The cosmological B-mode polarization is compared with models for the systematic noise induced by the galactic and extragalactic foregrounds in the Planck polarization channels. We have obtained that the 70 GHz channel have the lowest foregrounds induced noise level and, for the considered class of cosmological models, can detect the cosmological B-mode polarization at 3σ level for a tensor to scalar ratio r > 0.08. For greater tensor contributions, also the 100 GHz, 143 GHz and 44 GHz channels will be able to detect the CMB B-mode polarization. This work has been done on behalf of the Planck-LFI activities. (authors)