The Tayler instability at low magnetic Prandtl numbers: chiral symmetry breaking and synchronizable helicity oscillations

F. Stefani - V. Galindo - A. Giesecke - N. Weber - T. Weier

Helmholtz-Zentrum Dresden -- Rossendorf, Bautzner Landstr. 400, 01328 Dresden, Germany

Abstract
The current-driven, kink-type Tayler instability (TI) is a key ingredient of the Tayler-Spruit dynamo model for the generation of stellar magnetic fields, but it is also discussed as a mechanism that might hamper the up-scaling of liquid metal batteries. Under some circumstances, the TI involves a helical flow pattern which goes along with some α-effect. Here we focus on the chiral symmetry breaking and the related impact on the α-effect that would be needed to close the dynamo loop in the Tayler-Spruit model. For low magnetic Prandtl numbers, we observe intrinsic oscillations of the α-effect. These oscillations serve then as the basis for a synchronized Tayler-Spruit dynamo model, which could possibly link the periodic tidal forces of planets with the oscillation periods of stellar dynamos. Figs 4, Refs 46.