Interpreting superfluid spin up through the response of the container

Abstract

A recipe is presented for interpreting non-invasively the transport processes at work during relaxation of a cylindrical, superfluid-filled vessel, after it is accelerated impulsively and then allowed to respond to the viscous torque exerted by the contained fluid. The recipe exploits a recently published analytic solution for Ekman pumping in a two-component superfluid, which treats the back-reaction self-consistently in arbitrary geometry for the first time. The applicability of the recipe to He II, 3He, 3He-4He mixtures and Bose-Einstein condensates is assessed, and the effects of turbulence discussed.