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Title: Bifurcation analysis and dimension reduction of a predator-prey model for the L-H transition

The L-H transition denotes a shift to an improved confinement state of a toroidal plasma in a fusion reactor. A model of the L-H transition is required to simulate the time dependence of tokamak discharges that include the L-H transition. A 3-ODE predator-prey type model of the L-H transition is investigated with bifurcation theory of dynamical systems. The analysis shows that the model contains three types of transitions: an oscillating transition, a sharp transition with hysteresis, and a smooth transition. The model is recognized as a slow-fast system. A reduced 2-ODE model consisting of the full model restricted to the flow on the critical manifold is found to contain all the same dynamics as the full model. This means that all the dynamics in the system is essentially 2-dimensional, and a minimal model of the L-H transition could be a 2-ODE model.
Authors:
;  [1] ; ;  [2] ;  [3]
  1. Department of Applied Mathematics and Computer Science, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark)
  2. Association Euratom-DTU, Department of Physics, Technical University of Denmark, DTU Risø Campus, DK-4000 Roskilde (Denmark)
  3. Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)
Publication Date:
OSTI Identifier:
22218517
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 20; Journal Issue: 10; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BIFURCATION; DIFFERENTIAL EQUATIONS; ELECTRIC DISCHARGES; H-MODE PLASMA CONFINEMENT; HYSTERESIS; L-MODE PLASMA CONFINEMENT; PLASMA SIMULATION; PLASMA WAVES; THERMONUCLEAR REACTORS; TIME DEPENDENCE; TOKAMAK DEVICES; TWO-DIMENSIONAL CALCULATIONS