TEMPERATURE OSCILLATIONS OF AN ADIABATIC SUPERLEAK

We describe a new resonance of superfluid He-4 when confined in a supe rleak. In our experiment the superleak is sealed except at a filling h ole which communicates with bulk liquid. The resonance is driven and d etected thermally. The restoring force is provided by the compressibil ity of the helium under conditions which are very nearly adiabatic. We derive expressions for the resonance frequency, the lineshape and pha seshift and compare these with measurements on a 0.2113 mu m superleak .