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Title: Wall stabilization of high beta plasmas in DIII-D

Wall stabilization of high beta plasmas in DIII-D Detailed analysis of recent high beta discharges in the DIII-D tokamak demonstrates that the resistive vacuum vessel can provide stabilization of low n magnetohydrodynamic (MHD) modes. The experimental beta values reaching up to {beta}{sub T} = 12.6% are more than 30% larger than the maximum stable beta calculated with no wall stabilization. Plasma rotation is essential for stabilization. When the plasma rotation slows sufficiently, unstable modes with the characteristics of the predicted {open_quotes}resistive wall{close_quotes} mode are observed. Through slowing of the plasma rotation between the q = 2 and q = 3 surfaces with the application of a non-axisymmetric field, the authors have determined that the rotation at the outer rational surfaces is most important, and that the critical rotation frequency is of the order of {Omega}/2{pi} = 1 kHz.
Authors: ; ; ; ; ; ; ; ; ;
Publication Date:
OSTI Identifier:OSTI ID: 42489
Report Number(s):GA-A--21914; CONF-941101--9
ON: DE95009607; TRN: 95:003551
DOE Contract Number:AC03-89ER51114;AC05-84OR21400;W-7405-ENG-48
Resource Type:Conference
Resource Relation:Conference: Meeting of the Division of Plasma Physics of the American Physical Society, Minneapolis, MN (United States), 7-11 Nov 1994; Other Information: PBD: Feb 1995
Research Org:General Atomics, San Diego, CA (United States); Oak Ridge National Lab., TN (United States); Lawrence Livermore National Lab., CA (United States)
Sponsoring Org:USDOE, Washington, DC (United States)
Country of Publication:United States
Language:English
Subject: 70 PLASMA PHYSICS AND FUSION; DOUBLET-3 DEVICE; STABILIZATION; HIGH-BETA PLASMA; ROTATING PLASMA; MHD EQUILIBRIUM; VACUUM SYSTEMS