Thermal Conductivity of Liquid Helium. I

Abstract

Direct measurements have been made of the thermal conductivity of liquid helium over the temperature range from its normal boiling point at 4.2\ifmmode^\circ\else\textdegree\fi{}K to a temperature within a few hundredths of a degree of the $\ensuremath{\lambda}$-point. The results show that the thermal conductivity decreases linearly with temperature from a value of 6.5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}5}$ cal/deg cm sec at 4.2\ifmmode^\circ\else\textdegree\fi{}K to about 4.5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}5}$ cal/deg cm sec close to the $\ensuremath{\lambda}$-point. No large deviation from linearity can be detected in the heat conductivity until about 0.2 degree from the transition temperature of 2.18\ifmmode^\circ\else\textdegree\fi{}K.