Author: Bruce LipschultzPublisher:
ISBN:
Category : Tokamaks
Languages : en
Pages : 242
Book Description
Axisymmetric Instability in a Noncircular Tokamak
Author: Bruce LipschultzPublisher:
ISBN:
Category : Tokamaks
Languages : en
Pages : 242
Book Description
Axisymmetric Instability in a Noncircular Tokamak
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The stability of dee, inverse-dee and square cross section plasmas to axisymmetric modes has been investigated experimentally in Tokapole II, a tokamak with a four-null poloidal divertor. Experimental results are closely compared with predictions of two numerical stability codes -- the PEST code (ideal MHD, linear stability) adapted to tokapole geometry and a code which follows the nonlinear evolution of shapes similar to tokapole equilibria. Experimentally, the square is vertically stable and both dee's unstable to a vertical nonrigid axisymmetric shift. The central magnetic axis displacement grows exponentially with a growth time approximately 103 poloidal Alfven times plasma time. Proper initial positioning of the plasma on the midplane allows passive feedback to nonlinearly restore vertical motion to a small stable oscillation. Experimental poloidal flux plots are produced directly from internal magnetic probe measurements.
Axisymmetric Instability in a Noncircular Tokamak
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The stability of dee, inverse-dee and square cross section plasmas to axisymmetric modes has been investigated experimentally in Tokapole II, a tokamak with a four-null poloidal divertor. Experimental results are closely compared with predictions of two numerical stability codes - the PEST code (ideal MHD, linear stability) adapted to tokapole geometry and a code which follows the nonlinear evolution of shapes similar to tokapole equilibria.
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.
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.
Scientific and Technical Aerospace Reports
Author: Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 748
Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Stabilization of the Axisymmetric Instability of the PDX Tokamak
Author: S. C. JardinComputational Study of Axisymmetric Modes in Noncircular Cross Section Tokamaks
Author: John L. JohnsonPublisher:
ISBN:
Category : Tokamaks
Languages : en
Pages : 6
Book Description
Author: 
Author: N. Pomphrey