Kapitza Resistance at a Solid Helium-Copper Interface under Heavy Thermal Loads
Results were presented from three sets of measurements of the heat conduction between solid helium and a cold copper conductor in the 0.45 to 1.5K temperature range. The heat flux through the boundary could be described satisfactorily by Q = A(T He 4 - T Cu 4 ), with the parameter A weakly dependent on the temperature. That is, the temperature dependence of the Kapitza resistance RK = (1/4AT3) is close to the cubic dependence predicted by the acoustic detuning theory. However, the magnitude of RK is one to two orders smaller than that which is predicted and, in contrast with that theory, it does not depend on the density or sound velocity in He.