THERMAL-CONDUCTIVITY OF HE-4 VAPOR AS A FUNCTION OF DENSITY

Measurements of the dependence of the thermal conductivity λ (T, ρ{variant}) of 4He vapor on the density ρ{variant} are presented at 3.3 and 4.5 K. The initial dependence upon ρ{variant} near ρ{variant} = 0 agrees with the prediction of the modified Enskog theory; but at higher densities there are departures from the prediction. The excess thermal conductivity λ(T, ρ{variant}) - λ(T, 0) is independent of T within experimental error. © 1978 Plenum Publishing Corporation.