Institut de recherche sur les lois fondamentales de l'Univers

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 to 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 RK=(1.280.08) T -3 10-3 Km2W-1, and the thermal conductivity, κ = [(8.830.75)+(11.730.43)T] 10-3 Wm-1K-1.