Author: C.Z. ChengPublisher:
ISBN:
Category : Magnetohydrodynamic instabilities
Languages : en
Pages : 64
Book Description
Calculations of Axisymmetric Stability of Tokamak Plasmas with Active and Passive Feedback
Author: C.Z. ChengPublisher:
ISBN:
Category : Magnetohydrodynamic instabilities
Languages : en
Pages : 64
Book Description
Calculations of Axisymmetric Stability of Tokamak Plasmas with Active and Passive Feedback
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 64
Book Description
A new linear MHD stability code, NOVA-W, has been developed in order to study feedback stabilization of the axisymmetric mode in deformable tokamak plasmas. The NOVA-W code is a modification of the non-variational MHD stability code NOVA that includes the effects of resistive passive conductors and active feedback circuits. The vacuum calculation has been reformulated in terms of the perturbed poloidal flux to allow the inclusion of perturbed toroidal currents outside the plasma. The boundary condition at the plasma-vacuum interface relates the instability displacement to the perturbed poloidal flux. This allows a solution of the linear MHD stability equations with the feedback effects included. The passive stability predictions of the code have been tested both against a simplified analytic model and against a different numerical calculation for a realistic tokamak configuration. The comparisons demonstrate the accuracy of the NOVA-W results. Active feedback calculations are performed for the CIT tokamak design demonstrating the effect of varying the position of the flux loops that provide the measurements of vertical displacement. The results compare well with those computed earlier using a less efficient nonlinear code. 37 refs., 13 figs.
Energy Research Abstracts
Author: Feedback Stabilization of Axisymmetric Modes in Tokamaks
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Noncircular tokamak plasmas can be unstable to ideal MHD axisymmetric instabilities. Passive conductors with finite resistivity will at best slow down these instabilities to the resistive (L/R) time of the conductors. An active feedback system far from the plasma which responds on this resistive time can stabilize the system provided its mutual inductance with the passive coils is small enough.
Axisymmetric Instability in a Noncircular Tokamak
Author: Bruce LipschultzPublisher:
ISBN:
Category : Tokamaks
Languages : en
Pages : 242
Book Description
Active Feedback Stabilization of Axisymmetric Modes in Highly Elongated Tokamak Plasmas
Author: D.J. WardThe Effects of Plasma Deformability on the Feedback Stabilization of Axisymmetric Modes in Tokamak Plasmas
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 55
Book Description
The effects of plasma deformability on the feedback stabilization of axisymmetric modes of tokamak plasmas are studied. It is seen that plasmas with strongly shaped cross sections have unstable motion different from a rigid shift. Furthermore, the placement of passive conductors is shown to modify the non-rigid components of the eigenfunction in a way that reduces the stabilizing eddy currents in these conductors. Passive feedback results using several equilibria of varying shape are presented. The eigenfunction is also modified under the effects of active feedback. This deformation is seen to depend strongly on the position of the flux loops which are used to determine plasma vertical position for the active feedback system. The variations of these non-rigid components of the eigenfunction always serve to reduce the stabilizing effect of the active feedback system by reducing the measurable poloidal flux at the flux-loop locations. Active feedback results are presented for the PBX-M tokamak configuration.
Scientific and Technical Aerospace Reports
Author: Feedback Stabilization of the Axisymmetric Instability of a Deformable Tokamak Plasma
Author: N. PomphreyNumerical Methods and Applications
Author: Todor BoyanovPublisher: Springer Science & Business Media
ISBN: 3540709401
Category : Computers
Languages : en
Pages : 741
Book Description
This book constitutes the thoroughly refereed post-proceedings of the 6th International Conference on Numerical Methods and Applications, NMA 2006, held in Borovets, Bulgaria, in August 2006. The 84 revised full papers presented together with 3 invited papers were carefully reviewed and selected from 111 submissions. The papers are organized in topical sections on numerical methods for hyperbolic problems, robust preconditioning solution methods, Monte Carlo and quasi-Monte Carlo for diverse applications, metaheuristics for optimization problems, uncertain/control systems and reliable numerics, interpolation and quadrature processes, large-scale computations in environmental modelling, and contributed talks.