Experimental realization of dynamo action: present status and prospects

TL;DR

This paper reviews recent progress in experimental dynamo studies, highlights the significance of the VKS experiment, and discusses future prospects with the planned precession-driven dynamo experiment at DRESDYN.

Contribution

It presents numerical models linking the VKS dynamo's magnetic fields to soft iron components and discusses design studies for the upcoming precession dynamo experiment.

Findings

Numerical models show the relation between magnetic fields and soft iron in VKS.

Preparatory water experiments inform the design of the precession dynamo.

The paper outlines scientific prospects for future dynamo experiments.

Abstract

In the last decades, the experimental study of dynamo action has made great progress. However, after the dynamo experiments in Karlsruhe and Riga, the von-Karman-Sodium (VKS) dynamo is only the third facility that has been able to demonstrate fluid flow driven self-generation of magnetic fields in a laboratory experiment. Further progress in the experimental examination of dynamo action is expected from the planned precession driven dynamo experiment that will be designed in the framework of the liquid sodium facility DRESDYN (DREsden Sodium facility for DYNamo and thermohydraulic studies). In this paper, we briefly present numerical models of the VKS dynamo that demonstrate the close relation between the axisymmetric field observed in that experiment and the soft iron material used for the flow driving impellers. We further show recent results of preparatory water experiments and design studies related to the precession dynamo and delineate the scientific prospects for the final set-up.