Transport in very dilute solutions of He in superfluid He
arXiv:1212.2946
Abstract
Motivated by a proposed experimental search for the electric dipole moment of the neutron (nEDM) utilizing neutron-He capture in a dilute solution of He in superfluid He, we derive the transport properties of dilute solutions in the regime where the He are classically distributed and rapid He-He scatterings keep the He in equilibrium. Our microscopic framework takes into account phonon-phonon, phonon-He, and He-He scatterings. We then apply these calculations to measurements by Rosenbaum et al. [J.Low Temp.Phys. {\bf 16}, 131 (1974)] and by Lamoreaux et al. [Europhys.Lett. {\bf 58}, 718 (2002)] 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.
10 pages, 5 figures, v2