Transport in Very Dilute Solutions of 3 He in Superfluid 4 He

Transport in very dilute solutions of He-3 in superfluid He-4. Access to the published version may require subscription. Motivated by a proposed experimental search for the electric dipole moment of the neutron (nEDM) utilizing neutron-3 He capture in a dilute solution of 3 He in superfluid 4 He, we derive the transport properties of dilute solutions in the regime where the 3 He are classically distributed and rapid 3 He-3 He scatterings keep the 3 He in equilibrium. Our microscopic framework takes into account phonon-phonon, phonon-3 He, and 3 He-3 He scatterings. We then apply these calculations to measurements by Rosenbaum et al. of dilute solutions in the presence of a heat flow. We find satisfactory agreement of theory with the data, serving to confirm our understanding of the microscopics of the helium in the future nEDM experiment.