Phase diagram of turbulence in superfluid 3He-B

TL;DR

This study maps the phase diagram of turbulence in superfluid 3He-B, showing how vortex dynamics transition from regular to turbulent flow as temperature and pressure vary, using non-invasive NMR techniques.

Contribution

It provides the first detailed phase diagram of turbulence in superfluid 3He-B across different pressures and temperatures, highlighting the velocity-independent transition point.

Findings

Transition from regular to turbulent vortex motion occurs around 0.52--0.59Tc at high pressures.

Turbulence is not observed above 0.45Tc at zero pressure.

Transition width is narrow, about 0.06Tc.

Abstract

In superfluid 3He-B mutual-friction damping of vortex-line motion decreases roughly exponentially with temperature. We record as a function of temperature and pressure the transition from regular vortex motion at high temperatures to turbulence at low temperatures. The measurements are performed with non-invasive NMR techniques, by injecting vortex loops into a long column in vortex-free rotation. The results display the phase diagram of turbulence at high flow velocities where the transition from regular to turbulent dynamics is velocity independent. At the three measured pressures 10.2, 29.0, and 34 bar, the transition is centered at 0.52--0.59Tc and has a narrow width of 0.06Tc while at zero pressure turbulence is not observed above 0.45Tc.