2024 – Preventing Mode Coupling Using Applied 3d Magnetic Fields for Multimodal Entrainment

Preventing Mode Coupling Using Applied 3d Magnetic Fields for Multimodal Entrainment

2024 Research Campaign, Transient Control

Purpose of Experiment

The purpose of this experiment is to test whether 3d magnetic fields can be used to simultaneously entrain multiple magnetic islands and subsequently control the coupling between them. This is motivated by previous experiments that found that magnetic islands that form in tokamak plasmas can couple and result in deleterious effects, such as plasma disruption.

Experimental Approach

This experiment uses external 3d magnetic field coils to create a rotating magnetic field that acts to “entrain” the magnetic islands. The total field is comprised of two distinct structures that rotate at different frequencies. Each structure couples to and thus controls one of the magnetic islands. By changing the relative frequency between these two magnetic field structures, the magnetic islands entrained to these structure will also change their rotation frequency, and the coupling between the islands can be controlled.