Title: DIFFUSION IN TWO-COMPONENT QUASIPARTICLE SYSTEMS OF LIQUID AND SOLID MIXTURES OF HELIUM ISOTOPES
Authors: I.N.Adamenko, K.E.Nemchenko, A.V.Zhukov (Department of Physics and Technology, Kharkiv State University, 4 Svobody Sq., Kharkiv, 310077, Ukraine), Thomas F. George (Office of Chancellor, Departments of Chemistry, Physics and Astronomy, University of Wisconsin-Stevens Point, Wisconsin 54481-3897, U.S.A.), Lakshmi N. Pandey (Departments of Chemistry and Physics, Washington State University, Pullman, Washington 99164-4630, U.S.A.), Chung-In Um (Department of Physics, College of Science, Korea University, Seoul 136-701, Korea)

An exact expression for the diffusion time which depends on the interaction rates for particles of not only different, but also of the same species, has been derived from the system of kinetic equations. The result is valid for particles with arbitrary statistics and energy-momentum relations. The derived general relations are valid for investigating diffusion in liquid and solid $^3$He-$^4$He mixtures. The contribution of interaction between quasiparticles of the same type to the diffusion coefficient and effective thermal conductivity of superfluid solutions is analyzed. The calculated values are compared with experimental data. The calculated diffusion coefficient of $^3$He-$^4$He solid solutions differs from the previous theoretical results. A comparison of the obtained diffusion coefficient with experimental data makes it possible to determine the numerical value of the energy band width for impurity quasiparticles.

Comments: Figs. 3, Refs. 23, Tabs. 0.