Nonlinear three-dimensional self-consistent simulations of negative central shear discharges in the DIII-D tokamak

Citation
Am. Popov et al., Nonlinear three-dimensional self-consistent simulations of negative central shear discharges in the DIII-D tokamak, PHYS PLASMA, 8(8), 2001, pp. 3605-3619
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICS OF PLASMAS
ISSN journal
1070-664X → ACNP
Volume
8
Issue
8
Year of publication
2001
Pages
3605 - 3619
Database
ISI
SICI code
1070-664X(200108)8:8<3605:NTSSON>2.0.ZU;2-G
Abstract
Nonlinear simulations of experimentally observed magnetohydrodynamic (MHD) bursts in DIII-D [J. Luxon and L. G. Davis, Fusion Technol. 8, 441 (1985)] L-mode negative central magnetic shear (NCS) discharges were performed with a full three-dimensional nonlinear MHD code. The effects of plasma rotatio n in the presence of resistivity and viscosity are included and an effectiv ely implicit numerical scheme allows the transport profile to evolve self-c onsistently with the nonlinear MHD instabilities and externally applied sou rces and sinks. The simulations follow the MHD bursts and disruptions throu gh the linear and nonlinear phases and identify the connections between the early MHD bursts and the ultimate disruption phase. Specific predictions o f the growth and saturation of the modes are directly compared with experim ental diagnostic measurements in DIII-D. The simulations show that the burs ts observed in experiments are triggered by MHD instability of a resistive interchange mode and a resistive kink mode that are excited for critical pl asma profiles. The critical profiles are determined by the balance between inductive and noninductive sources of current density. (C) 2001 American In stitute of Physics.