Ballooning instabilities in tokamaks with sheared toroidal flows
The stability of ballooning modes in the presence of sheared toroidal flows is investigated. The eigenmodes are shown to be related by a Fourier transformation to the non-exponentially growing Floquet solutions found by Cooper. It is further shown that the problem cannot be reduced further than to a two dimensional partial differential equation. Next, the generalized ballooning equation is solved analytically for a circular tokamak equilibrium with sonic flows, but with a small rotation shear compared to the sound speed. With this ordering, the centrifugal forces are comparable to the pressure gradient forces driving the instability, but coupling of the mode with the sound wave is avoided. A new stability criterion is derived which explicitly demonstrates that flow shear is stabilizing at constant centrifugal force gradient. 34 refs.
- Research Organization:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Sponsoring Organization:
- DOE/ER
- DOE Contract Number:
- AC02-76CH03073
- OSTI ID:
- 6571080
- Report Number(s):
- PPPL-2719; ON: DE91002511; TRN: 90-034446
- Country of Publication:
- United States
- Language:
- English
Similar Records
Theory of high-n toroidicity-induced shear Alfven eigenmode in tokamaks
Theory of a high- n toroidicity-induced shear Alfven eigenmode in tokamaks
Related Subjects
TOKAMAK DEVICES
BALLOONING INSTABILITY
ASPECT RATIO
ASYMPTOTIC SOLUTIONS
BETA RATIO
DISPERSION RELATIONS
EIKONAL APPROXIMATION
EQUATIONS OF MOTION
FLUID FLOW
FOURIER TRANSFORMATION
MHD EQUILIBRIUM
PARTIAL DIFFERENTIAL EQUATIONS
PRESSURE GRADIENTS
SHEAR
WKB APPROXIMATION
CLOSED PLASMA DEVICES
DIFFERENTIAL EQUATIONS
EQUATIONS
EQUILIBRIUM
INSTABILITY
INTEGRAL TRANSFORMATIONS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
THERMONUCLEAR DEVICES
TRANSFORMATIONS
700107* - Fusion Energy- Plasma Research- Instabilities