Evolution of a decaying spheromak

Journal Article · Thu Oct 01 04:00:00 EDT 1987 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.866497· OSTI ID:6261666

Sgro, A G; Mirin, A A; Marklin, G

The evolution of a low beta spheromak initially in a two-dimensional stable equilibrium having a constant J/B (the so-called minimum energy state) is calculated within the context of resistive magnetohydrodynamics. Since the initial equilibrium is stable, the spheromak at first resistively evolves through a sequence of stable quasiequilibria. This phase of the evolution is calculated with a transport code in which the resistivity is assumed to be largest at the wall and lowest at the magnetic axis. Resistive diffusion causes the safety factor q to decrease everywhere while decreasing fastest near the wall. The quasiequilibria through which the spheromak evolves are tested for stability with both an ideal linear stability code and a resistive one. The results of both stability codes are in basic agreement and show that when q drops to below (1)/(2) everywhere the spheromak becomes unstable to an n = 2 mode. The agreement of the stability codes implies that the unstable mode is a resistively modified ideal mode. The unstable equilibrium is used as the initial

• Research Organization: Los Alamos National Laboratory, Los Alamos, New Mexico 87545
• OSTI ID: 6261666
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 30:10; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
CLOSED PLASMA DEVICES
CORRELATIONS
DIFFUSION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EQUILIBRIUM
FLUID MECHANICS
HYDRODYNAMICS
INSTABILITY
LOW-BETA PLASMA
MAGNETOHYDRODYNAMICS
MECHANICS
PHYSICAL PROPERTIES
PLASMA
PLASMA INSTABILITY
SIMULATION
SPHEROMAK DEVICES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES