Author: David John WardPublisher:
ISBN:
Category :
Languages : en
Pages : 336
Book Description
Studies of Feedback Stabilization of Axisymmetric Modes in Deformable Tokamak Plasmas
Author: David John 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.
The 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.
Active Feedback Stabilization of Axisymmetric Modes in Highly Elongated Tokamak Plasmas
Author: D.J. WardFeedback Stabilization of the Axisymmetric Instability of a Deformable Tokamak Plasma
Author: N. PomphreyFeedback Stabilization of Axisymmetric Modes in Tokamaks
Author: S. C. JardinFeedback 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.
Feedback Stabilization of the Axisymmetric Instability of a Deformable Tokamak Plasma
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
We analyze the magnetohydrodynamic (MHD) stability of the axisymmetric system consisting of a free boundary, non-circular cross-section tokamak plasma, finite resistivity passive conductors, and an active feedback system with magnetic flux pickup loops, a proportional amplifier with gain G, and current carrying poloidal field coils. Numerical simulation of a system that is unstable with G = 0 shows that for some placements of the pickup loops, the system will remain unstable for all values of G, while for other placements of the loops, the system will be stable for G> G/sub crit/. This behavior is explained by analysis using an extended energy principle, and it is shown to result from the deformability of the plasma cross section. 9 refs., 5 figs.
TSC Simulation of Feedback Stabilization of Axisymmetric Modes in Tokamaks Using Driven Halo Currents
Author: S. C. JardinPublisher:
ISBN:
Category : Tokamaks
Languages : en
Pages : 21
Book Description
Author: