Thermal expansion coefficient of 3He near 1 mK

A measurement of the thermal expansion coefficient of ³He at 0 bar from 0.6 to 3 mK is presented. At the superfluid transition the expansion coefficient changes by 1.1 × 10^s-6 mK^s-1. This change is consistent with predictions based on thermodynamic arguments and existing heat capacity data.This work was supported by NSF grant DMR 79-25098.