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Title: Status of Advanced Tokamak Scenario Modeling with Off-Axis Electron Cyclotron Current Drive in DIII-D

Status of Advanced Tokamak Scenario Modeling with Off-Axis Electron Cyclotron Current Drive in DIII-D The status of modeling work focused on developing the advanced tokamak scenarios in DIII-D is discussed. The objectives of the work are two-fold: (1) to develop AT scenarios with ECCD using time-dependent transport simulations, coupled with heating and current drive models, consistent with MHD equilibrium and stability; and (2) to use time-dependent simulations to help plan experiments and to understand the key physics involved. Time-dependent simulations based on transport coefficients derived from experimentally achieved target discharges are used to perform AT scenario modeling. The modeling indicates off-axis ECCD with approximately 3 MW absorbed power can maintain high-performance discharges with q{sub min} > 1 for 5 to 10 s. The resultant equilibria are calculated to be stable to n = 1 pressure driven modes. The plasma is well into the second stability regime for high-n ballooning modes over a large part of the plasma volume. The role of continuous localized ECCD is studied for stabilizing m/n = 2/1 tearing modes. The progress towards validating current drive and transport models, consistent with experimental results, and developing self-consistent, integrated high performance AT scenarios is discussed.
Authors: ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
OSTI Identifier:OSTI ID: 766945
Report Number(s):GA-A23310
TRN: US0110521
DOE Contract Number:AC03-99ER54463; AC05-96OR22464; W-7405-ENG-48; FG03-95ER54309
Resource Type:Conference
Resource Relation:Conference: 2nd IAEA Technical Committee Meeting on Steady-State Operation of Magnetic Fusion Devices, Fukuoka (JP), 10/25/1999--10/29/1999; Other Information: PBD: 1 Dec 1999
Research Org:General Atomics, San Diego, CA (US)
Sponsoring Org:US Department of Energy (US)
Country of Publication:United States
Language:English
Subject: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; DOUBLET-3 DEVICE; ECR HEATING; MHD EQUILIBRIUM; PERFORMANCE; MATHEMATICAL MODELS; ECR CURRENT DRIVE; COMPUTERIZED SIMULATION