DYNAMIC MEASUREMENTS NEAR THE LAMBDA-POINT IN A LOW-GRAVITY SIMULATORON THE GROUND

The properties of liquid helium very near the lambda-transition in the presence of a heat current has received recent theoretical and experi mental attention. In this regime, gravity induced pressure effects pla ce severe constraints on the types of experiments that can be performe d. A new experiment is described which largely overcomes these difficu lties by magnetostrictively cancelling gravity influences in the heliu m sample with a suitable magnetic coil. Design limitations of the tech nique and a discussion of proposed experiments is presented.