Unveiling the dynamics of tokamak plasmas: This research presents a gyrokinetic theory to explain long-term collisionless damping of a self-generated monopolar E × B vortex flow within a tokamak magnetic island. Through an explicit analytic calculation in the central island region, the theory demonstrates that the magnetic precession-induced coupling of the monopolar vortex to the island geodesic acoustic mode (IGAM) leads to oscillatory damping. The study reveals that IGAM differs qualitatively from both geodesic acoustic modes (GAM) and sound waves, emphasizing its unique characteristics. It demonstrates magnetic precession's role in damping the monopolar vortex. This is achieved through explicit analytic calculation to provide useful insights into the central island region. The theory also proposes utilizing the IGAM signal as an indicator of turbulence invasion into the tokamak magnetic island. This allows the IGAM signal to be better utlized as an indicator of turbulence invasion into the tokamak magnetic island.
This article aligns with the journal's scope by providing a theoretical analysis of plasma behavior within tokamak magnetic islands, contributing to the fundamental understanding of plasma physics and its applications in fusion energy research.