Study of the orientational electric field effect in 3He-B

We have studied the orienting effect that an electric field has on the orbital motion of the pairs in superfluid ³He-B, using the orientation-dependent transverse NMR frequency shift as a probe. This method provides high resolution for studying the orienting effect for either sign of the orientational energy. Electric fields as high as 35,000 V/cm applied across the sample produced no measurable frequency shift at 0-, 10-, and 32-bar pressures. This gives upper limits to the orientational energy of 1.4 × 10^s-3, 1.0 × 10^s-3 and 4 × 10^s-4 times the values expected from simple theory.