Some comments on the theory of the Kapitza conductance between metals and liquid helium II

A comparison has been made between calculations of the contribution to the Kapitza conductance between a metal and liquid helium II which arises through coupling between the surface modes and the conduction electrons. The calculation by Andreev (1962) which is based on the Boltzmann equation has been shown to be equivalent to a calculation by Khalatnikov (1952) in the limit of strong coupling. It has also been extended to the ωτ ≫ 1 region and shown to be in essential agreement with the quantum mechanical calculation by Little (1961). Numerical values have been computed for the analytical expressions which occur in these calculations.