Passive stabilization of MHD instabilities at high βn in the HBT-EP Tokamak
- Columbia Univ., New York, NY (United States)
The HBT-EP Tokamak has been designed, built, and is now fully operational in the Columbia University Plasma Physics Laboratory. One of the primary purposes of this facility is to study the effects of a conducting wall on the MHD modes that lead up to plasma disruptions. Of particular interest are the types of instabilities that are driven by the kinetic pressure of the plasma, because these instabilities are believed to be responsible for the present limit to plasma β with β ∝/B2, where the is the volume averaged pressure and B is the magnetic field. To this end, a movable conducting wall has been installed inside the HBT-EP vacuum chamber. The primary result of this thesis are the initial results from experiments that study the effect of this wall on plasma instabilities. The experiment shows that the conducting wall significantly reduces the growth rate of instabilities that precede a plasma disruption that occurs when the value of β is near the Troyon limit. The location of the wall required for significant stabilization is b/a ~1.2 where a is the minor radius of the plasma and b is the minor radial location of the wall. Moving the wall closer than b/a = 1.2 slightly degrades the stabilizing effect, which is consistent with recent theories.
- Research Organization:
- Columbia Univ., New York, NY (United States). Plasma Physics Lab.
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FG02-86ER53222
- OSTI ID:
- 10104897
- Report Number(s):
- DOE/ER/53222-108; ON: DE94003317; BR: AT0520210/AT0520230; TRN: 94:001368
- Resource Relation:
- Other Information: TH: Thesis (Ph.D.); PBD: 1993
- Country of Publication:
- United States
- Language:
- English
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TOKAMAK DEVICES
MHD EQUILIBRIUM
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INSTABILITY GROWTH RATES
VACUUM SYSTEMS
PLASMA DIAGNOSTICS
DATA ACQUISITION SYSTEMS
THOMSON SCATTERING
HIGH-BETA PLASMA
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PLASMA WAVES, OSCILLATIONS, AND INSTABILITIES
PLASMA FLUID AND MHD PROPERTIES