For lack of more detailed knowledge concerning the interactions between elementary excitations in liquid helium, Khalatnikov’s theory1 of transport phenomena has described such interactions in terms of δ-function potentials. Recent measurements by Herzlinger and King2 of the diffusion constant of very dilute 3He-4He solutions at temperatures slightly above 1°K call into question the validity of such simple models. It is indicated that the temperature variation of the kinetic coefficients may depend sensitively upon the form of the 3He—roton scattering cross section. We present here, as a first leg of the journey toward obtaining the diffusion coefficient D(T), a microscopic calculation of the effective 3He-roton cross section.
KeywordsDifferential Scattering Cross Section Correlate Basis Function Relevant Matrix Element Renormalize Phonon Incident Trajectory
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