A model for determining relaxation electric fields in spheromaks

Journal Article · Fri Nov 01 04:00:00 EST 1991 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.859795· OSTI ID:5242587

Mayo, R M ^[1]; Wysocki, F J; Fernandez, J C ^[2]

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1. Department of Nuclear Engineering, North Carolina State University, Raleigh, North Carolina (USA)
2. Los Alamos National Laboratory, Los Alamos, New Mexico (USA)

Past spheromak experiments have experienced poor confinement (Nucl. Fusion {bold 28}, 1555 (1988); Phys. Fluids B {bold 2}, 115 (1990)) as a result of edge-dominated helicity dissipation due to substantial field error and edge neutral inventory. Recent works have identified the importance of edge helicity loss and its effects on confinement (Phys. Fluids B {bold 2}, 115 (1990)). Herein, the results of the edge helicity dissipation model (Phys. Fluids {bold 30}, 1177 (1987)) are applied to determine the relative magnitudes of electric fields during relaxation in spheromaks. This is achieved by quantifying the average electric field in the plasma edge region generated by (a) flux decay and (b) relaxation mechanism(s). It is shown that relaxation electric fields can be as much as three times the flux decay field in the edge. The model also correctly predicts no relaxation electric field when the spheromak is a cold, purely resistively decaying object. In addition, the model provides an estimate for the quantity of magnetic decay power from relaxation, which can be as much as 75% of the total decay power.

• OSTI ID: 5242587
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 3:11; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
COLD PLASMA
CONFIGURATION
CONFINEMENT
ELECTRIC FIELDS
FLUID MECHANICS
HELICITY
HYDRODYNAMICS
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETOHYDRODYNAMICS
MECHANICS
PARTICLE PROPERTIES
PLASMA
PLASMA CONFINEMENT
RELAXATION
SPHERICAL CONFIGURATION
TURBULENCE