Polarization pursuers' guide - art. no. 083501

We calculate the detectability of the polarization of the cosmic microwave background (CMB) as a function of the sky coverage, angular resolution, and instrumental sensitivity for a hypothetical experiment. We consider the gr adient component of the polarization from density perturbations (scalar mod es) and the curl component from gravitational waves (tensor modes). We show that the amplitude (and thus the detectability) of the polarization from d ensity perturbations is roughly the same in any model as long as the model fits the big-bang-nucleosynthesis (BBN) baryon density and degree-scale ani sotropy measurements. The degree-scale polarization is smaller (and accordi ngly more difficult to detect) if the baryon density is higher. We show tha t the sensitivity to the polarization from density perturbations and gravit ational waves is improved (by a factor of 30) in a fixed-rime experiment wi th a deeper survey of a smaller region of sky.