Accurate 3He polarimetry using the Rb Zeeman frequency shift due to the Rb-3He spin-exchange collisions

We describe a method of ³He polarimetry relying on the polarization-dependent frequency shift of the Rb Zeeman resonance. Our method is ideally suited for on-line measurements of the ³He polarization produced by spin-exchange optical pumping. To calibrate the frequency shift we performed an accurate measurement of the imaginary part of the Rb-³He spin-exchange cross section in the temperature range typical for spin-exchange optical pumping of ³He. We also present a detailed study of possible systematic errors in the frequency shift polarimetry.