Three Dimensional Distortions of the Tokamak Plasma Boundary
Author : I. T. Chapman
Publisher :
Page : pages
File Size : 42,14 MB
Release : 2014
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Author : I. T. Chapman
Publisher :
Page : pages
File Size : 42,14 MB
Release : 2014
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Author : I.T. Chapman
Publisher :
Page : 32 pages
File Size : 17,83 MB
Release : 2013
Category : ITER Tokamak
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Author : I. T. Chapman
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Page : 16 pages
File Size : 30,32 MB
Release : 2013
Category : ITER Tokamak
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Author : I. T. Chapman
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Page : pages
File Size : 28,56 MB
Release : 2013
Category : Plasma instabilities
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Author : Ruth Laengner
Publisher : Forschungszentrum Jülich
Page : 175 pages
File Size : 45,77 MB
Release : 2013
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ISBN : 3893369244
Author :
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Page : 28 pages
File Size : 16,21 MB
Release : 1992
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Numerical solutions are described for three-dimensional MHD equilibria in the presence of resonant magnetic field perturbations. The effects of a realistic spectrum of resonant field errors are calculated for a range of current profiles. It is found that field errors of the magnitude existing in present day devices, and contemplated for future devices, can produce a set of magnetic islands occupying a significant fraction of the plasma cross-section.
Author : A. H. Reiman
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Page : 27 pages
File Size : 14,1 MB
Release : 1992
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Author :
Publisher :
Page : 564 pages
File Size : 39,89 MB
Release : 2004
Category : Airplanes
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Author :
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Page : 41 pages
File Size : 33,51 MB
Release : 2008
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The boundary plasma turbulence code BOUT models tokamak boundary-plasma turbulence in a realistic divertor geometry using modified Braginskii equations for plasma vorticity, density (ni), electron and ion temperature (T{sub e}; T{sub i}) and parallel momenta. The BOUT code solves for the plasma fluid equations in a three dimensional (3D) toroidal segment (or a toroidal wedge), including the region somewhat inside the separatrix and extending into the scrape-off layer; the private flux region is also included. In this paper, a description is given of the sophisticated physical models, innovative numerical algorithms, and modern software design used to simulate edge-plasmas in magnetic fusion energy devices. The BOUT code's unique capabilities and functionality are exemplified via simulations of the impact of plasma density on tokamak edge turbulence and blob dynamics.
Author : Nikolaos Vergos
Publisher :
Page : 352 pages
File Size : 35,23 MB
Release : 2016
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One of the most problematic instabilities in tokamak plasmas is tearing modes; they are driven by current and pressure gradients, and involve a reconfiguration of the magnetic and velocity fields localized into a narrow region located at a resonant magnetic surface. While the equilibrium magnetic field lines are located on concentric nested toroidal flux surfaces, the instability creates magnetic islands in which field lines connect flux tubes together, allowing for a high radial heat transport, and, thus, resulting in a loss of confinement, and, potentially, disruptions. In order for the magnetic field lines to break and reconnect, we need to take into account the resistivity of the plasma and solve the resistive magnetohydrodynamics (MHD) equations. The analytical solution consists of a boundary layer analysis (asymptotic matching) and takes advantage of the small radial width of the region where the perturbations vary significantly. Indeed, ideal magnetohydrodynamics can be used everywhere except in that narrow region where the full resistive problem must be solved. This dissertation addresses two related problems in the study of resistive tearing modes, and their interactions with externally induced resonant magnetic perturbations (error-fields). First, an in-depth investigation of the bifurcated states of a rotating, quasi-cylindrical, tokamak plasma in the presence of a resonant error-field is performed, within the context of constant-[greek letter psi] resistive MHD theory. The response of the rotating plasma is studied in both the linear, and the nonlinear regime. In general, there is a "forbidden band" of tearing mode rotation frequencies that separates a branch of high-frequency solutions from a branch of low-frequency solutions. When a high-frequency solution crosses the upper boundary of the forbidden band there is a bifurcation to a low-frequency solution, and vice versa. Second, the analysis is extended to include the study of braking and locking of tearing mode rotation by the interaction of the mode with an error-field. It is found that this interaction can brake the plasma rotation, suppress magnetic island evolution and drive locked modes.