PLANNED EXPERIMENT TO MEASURE THE SUPERFLUID DENSITY OF CONFINED HE-4NEAR T-LAMBDA

An experiment using Helmholtz resonator techniques is proposed to meas ure the effects of confinement on the superfluid density in He-4 near the lambda point. Recent experimental and technological innovations af ford the opportunity of dramatically improving previous measurements. We will exploit recent high resolution thermometry techniques which pr ovide 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 SQU ID readout to detect the small signal associated with a close approach to the transition.