Convection-Caused Symmetry Breaking of Azimuthal Magnetorotational Instability in a Liquid Metal Taylor-Couette Flow

TL;DR

This study demonstrates how thermal boundary conditions and convection influence the azimuthal magnetorotational instability in a liquid metal Taylor-Couette flow, revealing symmetry breaking and wave directionality.

Contribution

It provides experimental evidence of convection-induced symmetry breaking in AMRI and explores the interaction between thermal convection and magnetic instability.

Findings

Thermal boundary conditions significantly affect AMRI behavior.

Minimal radial heat flux causes symmetry breaking in AMRI.

Thermal convection interacts with magnetic instability, influencing wave propagation.

Abstract

We report the results of a liquid metal Taylor-Couette experiment in the Rayleigh-stable regime under the influence of an azimuthal magnetic field. We observe that the resulting azimuthal magnetorotational instability (AMRI) from our experimental setup is significantly influenced by the thermal boundary conditions. Even a minimal radial heat flux leads to a symmetry breaking, which results in the AMRI waves traveling either upwards or downwards. We identify the thermal radiation by the central axial current as the heat source responsible for vertical convection in the liquid. Preliminary numerical investigations point towards an interaction between AMRI and thermal convection, which supports our experimental findings.