Planned experiment to measure the superfluid density of confined He-4 near T-lambda

An experiment using Helmholtz resonator techniques is proposed to measure the effects of confinement on the superfluid density in He-4 near the lambda point. Recent experimental and technological innovations afford the opportunity of dramatically improving previous measurements. We will exploit recent high resolution thermometry techniques which provide a resolution of the lambda point to within 10(-9) K. In addition, the development of glass channel arrays with less than a one percent deviation throughout the entire array and high packing densities will provide a containment sample that is much improved over previous work. Finally, we will employ a high resolution pressure sensor with a SQUID readout to detect the small signal associated with a close approach to the transition.*