Surface Orientational Effects inB-He3

Abstract

We present measurements of large transverse resonance frequency shifts in NMR studies on superfluid $B$-${\mathrm{He}}^3$ contained in narrow channels separated by flat Mylar sheets. From these shifts we determine the orientation of the anisotropy axis with respect to the external field, and show that it is accurately determined by existing theory. We discuss the field dependence of the resonance shifts and present several new theoretical results which allow us to determine $H_B{R}_C$ from our data.