Kapitza resistance and thermal conductivity of Mylar at superfluid helium temperature

Abstract

The Kapitza resistance and the thermal conductivity of type A Mylar sheets in the temperature range between 1.4 and 2.1 K have been determined. Four sheets with varying thickness from 37 μm to 255 μm, have been tested in steady-state condition. For a small temperature difference (10–30 mK) and heat flux density smaller than 30 Wm −2, the total thermal resistance of the sheet is determined as a function of sheet thickness and bath temperature. The Kapitza resistance is given by R K = (1.28 ± 0.08) T −3 × 10 −3 Km 2 W −1, and the thermal conductivity, κ = [(8.83 ± 0.75) + (11.73 ± 0.43) × T] × 10 −3 Wm −1 K −1.