Polarized radial magnetic fields and outward plasma fluxes during shallow-reversal discharges in the ZT-40M reversed-field pinch

Journal Article · Sun Jan 01 04:00:00 EST 1984 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.332876· OSTI ID:5385158

Jacobson, A R; Rusbridge, M G; Burkhardt, L C

The characteristics of edge-region electromagnetic disturbances and of pulsed radial fluxes of plasma to the liner as well as the detailed interrelationship among these processes have been studied on the ZT-40M reversed-field pinch in its normal, shallow-reversal operating regime. The dominant magnetic disturbances are spiky (pulsewidth approx.5--10 ..mu..s) low-amplitude (Vertical BarB/sub r//B/sub theta/Vertical Bar< or approx. =10/sup -2/)= poloidally symmetric radial-field structures intersecting the vacuum wall and precessing toroidally in the anti-I/sub phi/ sense. The effect of even slight toroidal-field reversal (Vertical BarB/sub phi/(a)Vertical Barroughly-equalB/sub theta/(a)/10) is to polarize these radial-field spikes preferentially positive (i.e., B/sub r/>0) and to increase the speed of the minority (B/sub r/<0) while decreasing the speed of the majority (B/sub r/>0) spikes. Synchronous with the polarized B/sub r/ spikes are intense radially outward fluxes of plasma (instantaneously > or approx. =10/sup 22/ m/sup -2/ s/sup -1/) leading to recurrent, large amplitude (Vertical Bar..delta..n/n> or approx. =25%) depletion of the density in the outer quarter of minor radius. The resulting time-averaged global loss-rate per particle is significant (approx.10/sup 3/ s/sup -1/).

• Research Organization: Los Alamos National Laboratory, Los Alamos, New Mexico 87545
• OSTI ID: 5385158
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 55:1; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700104* -- Fusion Energy-- Plasma Research-- Plasma Kinetics-Experimental-- (-1987)
ELECTRIC DISCHARGES
EXPANSION
LINERS
MAGNETIC FIELDS
PINCH EFFECT
PLASMA
PLASMA DRIFT
PLASMA EXPANSION
POLARIZATION
REVERSE-FIELD PINCH
ZT-40 DEVICES