NIMROD resistive magnetohydrodynamic simulations of spheromak physics

Journal Article · Sat Mar 15 00:00:00 EDT 2008 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2890772· OSTI ID:21106168

Hooper, E B; Cohen, B I; McLean, H S; Wood, R D; Romero-Talamas, C A ^[1]; Sovinec, C R ^[2]

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1. University of California Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States)
2. Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706-1609 (United States)

The physics of spheromak plasmas is addressed by time-dependent, three-dimensional, resistive magnetohydrodynamic simulations with the NIMROD code [C. R. Sovinec et al., J. Comput. Phys. 195, 355 (2004)]. Included in some detail are the formation of a spheromak driven electrostatically by a coaxial plasma gun with a flux-conserver geometry and power systems that accurately model the sustained spheromak physics experiment [R. D. Wood et al., Nucl. Fusion 45, 1582 (2005)]. The controlled decay of the spheromak plasma over several milliseconds is also modeled as the programmable current and voltage relax, resulting in simulations of entire experimental pulses. Reconnection phenomena and the effects of current profile evolution on the growth of symmetry-breaking toroidal modes are diagnosed; these in turn affect the quality of magnetic surfaces and the energy confinement. The sensitivity of the simulation results addresses variations in both physical and numerical parameters, including spatial resolution. There are significant points of agreement between the simulations and the observed experimental behavior, e.g., in the evolution of the magnetics and the sensitivity of the energy confinement to the presence of symmetry-breaking magnetic fluctuations.

• OSTI ID: 21106168
• Journal Information: Physics of Plasmas, Vol. 15, Issue 3; Other Information: DOI: 10.1063/1.2890772; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CURRENTS
ELECTRIC POTENTIAL
FLUCTUATIONS
GEOMETRY
MAGNETIC RECONNECTION
MAGNETIC SURFACES
MAGNETOHYDRODYNAMICS
NIMROD
NONLINEAR PROBLEMS
PLASMA
PLASMA CONFINEMENT
PLASMA GUNS
PLASMA SIMULATION
POWER SYSTEMS
SENSITIVITY
SPATIAL RESOLUTION
SPHEROMAK DEVICES
THREE-DIMENSIONAL CALCULATIONS
TIME DEPENDENCE