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arXiv · 2602.07329

Topological Arrest of Ballooning Modes in Non-Axisymmetric Plasmas

Amitava Bhattacharjee
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Abstract

Why do non-axisymmetric stellarators avoid ballooning crashes that afflict tokamaks? Three-dimensional geometry induces Anderson localization of ballooning modes, converting a global instability into a Ginzburg--Landau network of isolated wave packets. Global stability reduces to a percolation problem: below a critical threshold, instability is arrested; above it, a crash occurs. This explains benign stellarator saturation, predicts vulnerability in quasisymmetric designs, and introduces the critical threshold as a nonlinear stability metric for reactor optimization, pending experimental validation.

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Amitava Bhattacharjee. 2026-02-07. Topological Arrest of Ballooning Modes in Non-Axisymmetric Plasmas. https://arxiv.org/abs/2602.07329

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