Evolution of flux-conserving tokamak equilibria with preprogrammed cross sections

Journal Article · Sun Jun 01 04:00:00 EDT 1980 · J. Comput. Phys.; (United States)

DOI:https://doi.org/10.1016/0021-9991(80)90173-4· OSTI ID:5293167

Holmes, J A; Peng, Y M; Lynch, S J

The evolution of MHD equilibria toward high ..beta.. is modeled by magnetic flux conservation with a given q(psi) and by single fluid particle and energy balances which determine p(psi, t). These one-dimensional flux surface averaged equations, written with magnetic flux psi as the independent varianle, are coupled to the two-dimensional MHD equilibrium equation through psi, p(psi, t), and q(psi). The location an evolution of the plasma cross section boundary are precisely specified through the use of a fixed boundary equilibrium technique. In moving boundary studies (e.g., plasma compression) the resulting system of equations is advanced in time from an inital state by a procedure which utilizes two nested predictor-corrector loops together with an implicit time-stepping technique. The inner predictor-corrector loop advances the transport equations subject to a given equilibrium configuration while the outer loop evolves the equilibrium. For fixed plasma boundaries this procedure is modified for greater computational speed. These techniques provide satisfactory numerical convergence together with complete consistency between the coupled one-dimensional system of equations and the two-dimensional equilibrium. This method can be applied to the study of equilibrium evolution involving dramatic changes of plasma position, shape, an profiles while prescribing the evolution of the plasma boundary. As such, it can serve as a useful tool in the design of poloidal field systems or as a source of equilibria in high-..beta.. MHD stability studies. As an example, the compressional scaling laws of Furth and Yoshikawa are found to be modified for small aspect ratio.

• Research Organization: Computer Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5293167
• Journal Information: J. Comput. Phys.; (United States), Journal Name: J. Comput. Phys.; (United States) Vol. 36:1; ISSN JCTPA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
BOUNDARY-VALUE PROBLEMS
CLOSED PLASMA DEVICES
COMPRESSION
ENERGY BALANCE
FLUID MECHANICS
HIGH-BETA PLASMA
HYDRODYNAMICS
MAGNETIC FLUX
MAGNETOHYDRODYNAMICS
MECHANICS
MONTE CARLO METHOD
PLASMA
SCALING LAWS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TRANSPORT THEORY