MHD stability and control for mirror machines
MHD stability properties of magnetic mirrors are examined theoretically. A second-order differential equation, governing the resistive ballooning-mode instability for an arbitrary plasma beta, is derived from a set of fluid equations. The resistive effects on the Berkeley 10-m multiple Mirror Experiment (MMX) stabilized by a conducting wall, cusps, and quadrupoles are numerically examined and compared with the know experimental results. Numerical results show that the resistive effects play a dominant role on the low-temperature MMX. The possibility of feedback stabilization of the m = 1 flute mode for axisymmetric mirror machines is also considered. A three-region plasma model is developed and analyzed, consisting of a hot-core surrounded by a warm-transition annulus, which in turn is surrounded by a warm-halo annulus that is in contact with the feedback plates at the two endwalls. By a proper choice of feedback function, the m = 1 flute mode on the core plasma is stabilized by feedback signals applied to segmented, ring-shaped feedback plates. For the axisymmetric MMX, TMX-U, and MFTF-B, the required feedback power and its scaling with plasma parameters are calculated. Results show that stability can be achieved in the MMX and TMX-U devices with a modest feedback gain and power. The power requirement for MFTF-B is more severe, but can be reduced by a modified choice of plasma parameters.
- Research Organization:
- California Univ., Berkeley (USA)
- OSTI ID:
- 5299745
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Power deposition profiles in Maxwellian magneto-active plasmas
TMX tandem-mirror experiments and thermal-barrier theoretical studies
Related Subjects
MAGNETIC MIRRORS
CONTROL
MHD EQUILIBRIUM
BALLOONING INSTABILITY
FEEDBACK
FLUTE INSTABILITY
STABILITY
EQUILIBRIUM
INSTABILITY
OPEN PLASMA DEVICES
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
THERMONUCLEAR DEVICES
700107* - Fusion Energy- Plasma Research- Instabilities