Ion shielding effects on the resonant boundary layer response to magnetic perturbations

TL;DR

This paper extends boundary layer theory to include ion parallel flow effects at the plasma resonant layer, predicting ion shielding against magnetic disruptions in fusion plasmas.

Contribution

It introduces a novel nested boundary layer approach to better understand ion shielding effects in the resonant boundary layer response.

Findings

Supports previous numerical results with new analytic predictions

Suggests ion shielding can mitigate magnetic disruptions in future devices

Extends classical boundary layer theory to include ion flow physics

Abstract

Fusion plasmas are highly sensitive to external magnetic perturbations which result in complex responses near a region known as the resonant layer. Past analytic descriptions of this phenomena used boundary layer theory in a simplified system assuming low plasma beta to predict the onset of instabilities. Here, we present a novel extension of the analytic theory utilizing nested boundary layers to capture the physics of ion parallel flow at the plasma resonant layer. This new prediction supports previous numerical results and suggests ion shielding against magnetic disruptions in parameter regimes relevant to future device operation.