Modeling of Neoclassical Tearing Mode Stability for Generalized Toroidal Geometry

Technical Report · Wed Aug 21 04:00:00 EDT 2002

DOI:https://doi.org/10.2172/808391· OSTI ID:808391

Rosenberg, A L ^[1]; Gates, D A; Pletzer, A; Menard, J E; Kruger, S E; Hegna, C C; Paoletti, F; Sabbagh, S

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1. Princeton Plasma Physics Laboratory

Neoclassical tearing modes (NTMs) can lead to disruption and loss of confinement. Previous analysis of these modes used large aspect ratio, low beta (plasma pressure/magnetic pressure) approximations to determine the effect of NTMs on tokamak plasmas. A more accurate tool is needed to predict the onset of these instabilities. As a follow-up to recent theoretical work, a code has been written which computes the tearing mode island growth rate for arbitrary tokamak geometry. It calls PEST-3 [A. Pletzer et al., J. Comput. Phys. 115, 530 (1994)] to compute delta prime, the resistive magnetohydrodynamic (MHD) matching parameter. The code also calls the FLUXGRID routines in NIMROD [A.H. Glasser et al., Plasma Phys. Controlled Fusion 41, A747 (1999)] for Dnc, DI and DR [C.C. Hegna, Phys. Plasmas 6, 3980 (1999); A.H. Glasser et al., Phys. Fluids 18, 875 (1975)], which are the bootstrap current driven term and the ideal and resistive interchange mode criterion, respectively. In addition to these components, the NIMROD routines calculate alphas-H, a new correction to the Pfirsch-Schlter term. Finite parallel transport effects were added and a National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 (2000)] equilibrium was analyzed. Another program takes the output of PEST-3 and allows the user to specify the rational surface, island width, and amount of detail near the perturbed surface to visualize the total helical flux. The results of this work will determine the stability of NTMs in an spherical torus (ST) [Y.-K.M. Peng et al., Nucl. Fusion 26, 769 (1986)] plasma with greater accuracy than previously achieved.

• Research Organization: Princeton Plasma Physics Lab., NJ (US)
• Sponsoring Organization: USDOE Office of Science (US)
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 808391
• Report Number(s): PPPL-3740
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
A CODES
ACCURACY
ASPECT RATIO
BOOTSTRAP CURRENT
CONFINEMENT
GEOMETRY
ISLANDS
MAGNETOHYDRODYHAMICS (MHD)
MAGNETOHYDRODYNAMICS
MHD INSTABILITY
MODE RATIONAL SURFACES
NIMROD
PLASMA
SIMULATION
STABILITY
TOKAMAKS (NSTX)
TRANSPORT