SELF-CALIBRATING MEASUREMENT OF POLARIZATION-DEPENDENT FREQUENCY-SHIFTS FROM RB-HE-3 COLLISIONS

We have studied the frequency shift in the Rb electron-paramagnetic-re sonance (EPR) line due to the presence of nuclear polarized He-3. By m easuring the resonant frequency in a cylindrical cell oriented both pa rallel and perpendicular to an applied magnetic field, we determined t he classical EPR shift due to long-range macroscopic fields. We thus c alibrated the larger, geometry-independent shift, due to the Fermi-con tact interaction between the Rb electron and the He-3 nucleus, to 2.5% . The EPR frequency shift can be used to determine the He-3 nuclear po larization.