Chaotic escape of impurities and sticky orbits in toroidal plasmas.

Autor:	Souza LC; Universidade Federal do Paraná, Departamento de Física, Curitiba, PR 81531-990, Brazil., Sales MR; Universidade Estadual de Ponta Grossa, Programa de Pós-Graduação em Ciências, Ponta Grossa, PR 84030-900, Brazil., Mugnaine M; Universidade de São Paulo, Instituto de Física, São Paulo, SP 05315-970, Brazil., Szezech JD; Universidade Estadual de Ponta Grossa, Programa de Pós-Graduação em Ciências, Ponta Grossa, PR 84030-900, Brazil., Caldas IL; Universidade de São Paulo, Instituto de Física, São Paulo, SP 05315-970, Brazil., Viana RL; Universidade Federal do Paraná, Departamento de Física, Curitiba, PR 81531-990, Brazil.; Universidade de São Paulo, Instituto de Física, São Paulo, SP 05315-970, Brazil.
Jazyk:	angličtina
Zdroj:	Physical review. E [Phys Rev E] 2024 Jan; Vol. 109 (1-2), pp. 015202.
DOI:	10.1103/PhysRevE.109.015202
Abstrakt:	We investigate chaotic impurity transport in toroidal fusion plasmas (tokamaks) from the point of view of passive advection of charged particles due to E×B drift motion. We use realistic tokamak profiles for electric and magnetic fields as well as toroidal rotation effects, and consider also the effects of electrostatic fluctuations due to drift instabilities on particle motion. A time-dependent one degree-of-freedom Hamiltonian system is obtained and numerically investigated through a symplectic map in a Poincaré surface of section. We show that the chaotic transport in the outer plasma region is influenced by fractal structures that are described in topological and metric point of views. Moreover, the existence of a hierarchical structure of islands-around-islands, where the particles experience the stickiness effect, is demonstrated using a recurrence-based approach.
Databáze:	MEDLINE
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