The ideal versus the reality: topology and turbulence in the current density in tokamak

Tangled Magnetic Fields in Astro- and Plasma Physics; Quantised Flux in Tightly Knotted and Linked Systems

Spineanu, F.^1 ; Vlad, M.^1

National Institute of Laser, Plasma and Radiation Physics, Magurele Bucharest, Romania^1

关键词: Collision regimes;    Current density profiles;    Magnetic reconnections;    Magnetically confined plasmas;    Principle of Maximum Entropy;    Self organizations;    Statistical approach;    Theoretical solutions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/544/1/012011/pdf
DOI  :  10.1088/1742-6596/544/1/012011

来源: IOP

【 摘 要 】

Models for the current density profile in magnetically confined plasma have been proposed starting from first principles, basically in analogy with the self-organization of the vorticity in the two-dimensional Euler fluid. The principle of maximum entropy has led to the derivation of the Liouville equation, under some criticism regarding the possibility of a statistical approach. We identify a class of asymptotic stationary states for the coupled fields of current-density and vorticity, using the Backlund transform. For this class of asymptotic states the maxima of the vorticity and current density must coincide. We also discuss a possible relevance of the field-theoretical solutions sphaleron for magnetic reconnection in low-collision regimes.