A New Concept in Positron Polarimetry

We outline a novel experimental technique for measuring the degree of polarization of a positron beam using an optically pumped, spin-polarized Rb target. The technique is based on the production and measurement of the ortho- and para-positronium fractions through positron collisions with the Rb as a function of their polarization. Using realistic estimates for the cross sections and experimental parameters involved we estimate that a polarization measurement with 1% uncertainty of the measured value can be achieved in a few minutes.