Measurement of Kapitsa resistance using second sound in He II
A. N. Tsoi, Sergey K. Nemirovskii · Soviet Journal of Low Temperature Physics · 1980
The effect of the Kapitsa resistance on the boundary conditions in acoustic experiments is discussed. We show that the correct calculation of the temperature resistance and of the thermal balance leads to a relaxation type of process of thermal energy transfer into the bulk helium, with a characteristic time τ = RC(R is the Kapitsa resistance, C is the specific heat per unit surface). This fact can be used to measure R in the following way: As is known, the speed of second sound depends on the signal amplitude which, in turn, is a function of τ(R); consequently, the speed of the second sound signal is connected to the boundary resistance R in a unique way.