Effective Viscosity of Liquid Helium 4 - With Minute He3 Impurity at Temperatures from 0.05K to 2K and at Velocities Spanning the Critical Velocities

摘要

This report presents a comprehensive analysis of three Experimental Series on the measurements of the effective viscosity of liquid He(4) with minute He(3) impurity taken with a Couette viscometer at temperatures between 0.05K and 2K, and at viscometer velocities which span the liquid helium critical velocities. A comprehensive theory of the velocity independent effective viscosity of liquid He(4) with minute He(3) impurity is developed for parallel plate geometry and is found to well represent the experimental measurements. The velocity independent viscosity measurements taken at temperatures above 0.8K were in agreement with the experimental measurements of the coefficient of viscosity made by Woods and Hollis Hallet. As the temperature T was lowered below 1.8K, the viscosity rose rapidly, approaching a T to the minus 9th power temperature dependence. Then below 0.8K the rapid rise quickly diminished. The diminution in the effective viscosity of liquid He4 of high purity is so rapid that it extrapolates to a nearby frictionless fluid at temperatures below 0.1K. This nearly frictionless property of liquid He4 should provide unprecedented opportunities for the development of inertial instruments of the highest precision.