Rotating quantum turbulence in superfluid 4He in the T=0 limit

TL;DR

This paper reports on experimental observations of quantum turbulence in superfluid helium-4 under rotation, revealing how vortex tangles develop and resonate with inertial waves, using novel forcing and detection techniques.

Contribution

It introduces new experimental methods for inducing and detecting quantum turbulence in superfluid helium-4 in a rotating setup, and characterizes the turbulence development and resonances.

Findings

Vortex tangle grows without threshold near axial walls.

Bulk turbulence develops at a characteristic forcing amplitude.

Resonances of inertial waves influence turbulence onset.

Abstract

Observations of quantum turbulence in pure superfluid 4He in a rotating container are reported. New techniques of large-scale forcing (rotational oscillations of the cubic container) and detecting (monitoring ion transport along the axis of rotation) turbulence were implemented. Near the axial walls, with increasing forcing the vortex tangle grows without an observable threshold. This tangle gradually develops into bulk turbulence at a characteristic amplitude of forcing that depends on forcing frequency and rotation rate. At higher amplitudes, the total vortex line length increases rapidly. Resonances of inertial waves are observed in both laminar and turbulent bulk states. On such resonances, the turbulence appears at smaller amplitudes of forcing.