Tokamak plasma variations under rapid compression

Journal Article · Tue Jan 01 04:00:00 EST 1980 · Physics of Fluids

DOI:https://doi.org/10.1063/1.863214· OSTI ID:1024772

Holmes, J. A. ^[1]; Peng, Yueng Kay Martin ^[2]; Lynch, S. J. ^[1]

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1. Oak Ridge National Laboratory (ORNL)
2. ORNL

Changes in plasmas undergoing large, rapid compressions are examined numerically over the following range of aspect ratios A: 3> or {approx_equal}A> or {approx_equal}1.5 for major radius compressions of circular, elliptical, and D-shaped cross sections; and 3< or {approx_equal}A< or {approx_equal}6 for minor radius compressions of circular and D-shaped cross sections. The numerical approach combines the computation of fixed boundary magnetohydrodynamic equilibria with single-fluid, flux-surface-averaged energy balance, particle balance, and magnetic flux diffusion equations. It is found that the dependences of plasma current I{sub p} and volume-averaged poloidal beta beta-bar{sub p} on the compression ratio C differ significantly in major radius compressions from those proposed by Furth and Yoshikawa. The present interpretation is that compression to small A dramatically increases the plasma current, which lowers beta-bar{sub p} and makes the plasma more paramagnetic. Despite large values of volume-averaged toroidal beta beta-bar{sub t} (> or {approx_equal}30% with safety factor q{approx_equal}1 at the magnetic axis, q{approx_equal}3 at the plasma edge), this tends to concentrate more toroidal flux near the magnetic axis, which means that a reduced minor radius is required to preserve the continuity of the toroidal flux function F at the plasma edge. Minor radius compressions to large aspect ratio agree well with the Furth-Yoshikawa scaling laws.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1024772
• Journal Information: Physics of Fluids, Journal Name: Physics of Fluids Journal Issue: 9 Vol. 23; ISSN 0031-9171
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANNULAR SPACE
ASPECT RATIO
BOUNDARY CONDITIONS
CLOSED PLASMA DEVICES
COMPRESSION RATIO
CROSS SECTIONS
DIFFUSION EQUATIONS
ELECTRIC CURRENTS
ENERGY BALANCE
FLUID MECHANICS
HYDRODYNAMICS
MAGNETIC FLUX
MAGNETISM
MAGNETOHYDRODYNAMICS
MECHANICS
NUMERICAL SOLUTION
PARAMAGNETISM
PLASMA SIMULATION
SCALING LAWS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TOROIDAL CONFIGURATION