Persistent Currents in a Rotating Superleak Partially Filled with Superfluid Helium.

摘要

Persistant currents in a partially hellium II filled rotating super-leak have been investigated. Measurements were made using the acoustic doppler shift of the thickness wave in the helium II film which covers the alumina powder grains (1 micron) of the superleak. The existence of a potential flow region (Landau region) was established and measured at low rotational speeds (below 0.5 Hz). The decay rates of persistant current velocities were measured over almost five decades of time. We found a one-to-one correspondence with our system and that of a helium II filled superleak and also to the analogous quantities in an irreversible type-II superconductor.