OPTICAL OBSERVATIONS ON HE-3-B SUPERFLUID

Optical observations on the free surface of superfluid He-3-B have bee n made using an interferometer. The change in viscosity was seen at th e superfluid transition, and the fountain effect in He-3-B was observe d directly. The equilibrium average density of vortices was ascertaine d by looking at the reflection of light from the free surface of the r otating superfluid. Heat leaks due to illumination were investigated. Our results will be illustrated by a video film showing the similariti es and differences between the superfluid and the normal liquid.