Magnetic flux conversion and relaxation toward a minimum-energy state in spheromak plasmas

Journal Article · Wed Oct 01 04:00:00 EDT 1986 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.865849· OSTI ID:5195608

Janos, A

S-1 spheromak (Plasma Physics and Controlled NuclearFusion, 1984 (IAEA, Vienna, Austria, 1985), Vol. 2, p. 535) currents and magnetic fluxes have been measured with Rogowski coils and flux loops external to the plasma. Toroidal plasma currents up to 350 kA and spheromak configuration lifetimes over 1.0 msec have been achieved at moderate power levels. The plasma formation in the S-1 spheromak device is based on an inductive transfer of poloidal and toroidal magnetic flux from a toroidal ''flux core'' to the plasma. Formation is programmed to guide the configuration into a force-free, minimum-energy Taylor state. Properly detailed programming of the formation process is found not to be essential since plasmas adjust themselves during formation to a final equilibrium near the Taylor state. After formation, if the plasma evolves away from the stable state, then distinct relaxation oscillation events occur that restore the configuration to that stable state. The relaxation process involves reconnection of magnetic field lines, and conversion of poloidal to toroidal magnetic flux (and vice versa) has been observed and documented. The scaling of toroidal plasma current and toroidal magnetic flux in the plasma with externally applied currents is consistent with the establishment of a Taylor state after formation.

• Research Organization: Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08544
• OSTI ID: 5195608
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 29:10; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101 -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
700107* -- Fusion Energy-- Plasma Research-- Instabilities
CLOSED PLASMA DEVICES
CONFINEMENT
CONVERSION
MAGNETIC FLUX
PLASMA
PLASMA CONFINEMENT
RELAXATION
SPHEROMAK DEVICES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES