Alfvenic propagation: a key to nonlocal effects in magnetized plasmas

TL;DR

This paper demonstrates that incorporating induction effects into plasma response models explains nonlocal temperature perturbations in magnetized plasmas, resolving longstanding experimental puzzles in fusion research.

Contribution

It introduces a model combining induction effects with local diffusive transport to accurately reproduce experimental nonlocal plasma behavior.

Findings

Induction effects are crucial for explaining nonlocal temperature responses.

The model quantitatively matches experimental data.

Nonlocal effects are explained by Alfvenic propagation mechanisms.

Abstract

A long standing puzzle in fusion research comes from experiments where a sudden peripheral electron temperature perturbation is accompanied by an almost simultaneous opposite change in central temperature, in a way incompatible with local transport models. This paper shows these experiments and similar ones are fairly well quantitatively reproduced, when induction effects are incorporated in the total plasma response, alongside standard local diffusive transport, as suggested in earlier work [V.D. Pustovitov, Plasma Phys. Control. Fusion {\bf 54}, 124036 (2012)].