Analytic regimes of tokamak plasma

TL;DR

This paper explores specific analytic regimes of tokamak plasma where the Larmor radius and orientation angle form an analytic function, potentially leading to widespread transport barriers and multiple temperature maxima in plasma confinement.

Contribution

It introduces a novel class of analytic regimes based on complex function theory, linking plasma behavior to global conservation laws and transport barrier formation.

Findings

Transport barriers could extend throughout the plasma

Multiple temperature maxima can occur in these regimes

Analytic regimes are characterized by complex function properties

Abstract

The paper suggests certain regimes of fusion plasma with magnetic confinement, when the Larmor radius $\lambda$ and the angle $\alpha$ (determining the orientation of the local coordinates) form an analytic function $w=\lambda e^{i\alpha}$ of complex variable $z=x_1+i x_2$ ($x_1$ and $x_2$ are coordinates of tokamak cross-section). It is known that an efficient nuclear fusion requires transport barriers, which might be due to zonal/poloidal flow; and the emergence of such flow is implied by the adiabatic extra conservation (established in a local slub). The suggested analytic regimes are based on the global extension of this extra conservation; transport barriers could spread to the entire tokamak plasma. It is interesting that in these regimes, plasma temperature reaches maximum often not at a single location (of tokamak cross-section), but at several points separated by regions of lower temperature.