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Title: Passive stabilization of MHD instabilities at high βn in the HBT-EP Tokamak

Abstract

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 ∝/B 2, 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 thanmore » b/a = 1.2 slightly degrades the stabilizing effect, which is consistent with recent theories.« less

Authors:
 [1]
  1. Columbia Univ., New York, NY (United States)
Publication Date:
Research Org.:
Columbia Univ., New York, NY (United States). Plasma Physics Lab.
Sponsoring Org.:
USDOE
OSTI Identifier:
10104897
Report Number(s):
DOE/ER/53222-108
ON: DE94003317; BR: AT0520210/AT0520230; TRN: 94:001368
DOE Contract Number:  
FG02-86ER53222
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: TH: Thesis (Ph.D.); PBD: 1993
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; TOKAMAK DEVICES; MHD EQUILIBRIUM; PLASMA INSTABILITY; INSTABILITY GROWTH RATES; VACUUM SYSTEMS; PLASMA DIAGNOSTICS; DATA ACQUISITION SYSTEMS; THOMSON SCATTERING; HIGH-BETA PLASMA; 700340; 700370; PLASMA WAVES, OSCILLATIONS, AND INSTABILITIES; PLASMA FLUID AND MHD PROPERTIES

Citation Formats

Gates, David A. Passive stabilization of MHD instabilities at high βn in the HBT-EP Tokamak. United States: N. p., 1993. Web. doi:10.2172/10104897.
Gates, David A. Passive stabilization of MHD instabilities at high βn in the HBT-EP Tokamak. United States. https://doi.org/10.2172/10104897
Gates, David A. Fri . "Passive stabilization of MHD instabilities at high βn in the HBT-EP Tokamak". United States. https://doi.org/10.2172/10104897. https://www.osti.gov/servlets/purl/10104897.
@article{osti_10104897,
title = {Passive stabilization of MHD instabilities at high βn in the HBT-EP Tokamak},
author = {Gates, David A.},
abstractNote = {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.},
doi = {10.2172/10104897},
url = {https://www.osti.gov/biblio/10104897}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1993},
month = {1}
}

Thesis/Dissertation:
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