Drift stabilization of tearing modes and the L--H transition

Journal Article · Wed Apr 01 04:00:00 EST 1992 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.860109· OSTI ID:7046777

Strauss, H R ^[1]

---

1. Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)

The L to H-mode transition is accompanied by a drop in the magnetic signal of a mode with low toroidal mode number, usually {ital n}=1. Quasilinear drift stabilization can cause a saturated tearing mode to collapse, under the conditions at the edge of a tokamak plasma. The criterion for stabilization gives a relation of temperature to magnetic field {ital T}{proportional to}{ital B}{sup {alpha}}, with 6/7{ge}{alpha}{ge}2/3. The collapse of the island could trigger the H mode by reducing the stochastic magnetic field layer around the magnetic separatrix. This would improve edge confinement, helping to form a transport barrier. Improvement of electron edge confinement could make the electric field more negative, producing the rotation seen in experiments.

• DOE Contract Number: FG02-86ER53223
• OSTI ID: 7046777
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 4:4; ISSN PFBPE; ISSN 0899-8221
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
BALLOONING INSTABILITY
CLOSED PLASMA DEVICES
CONFINEMENT
ELECTRIC FIELDS
INSTABILITY
MAGNETIC FIELDS
PLASMA
PLASMA CONFINEMENT
PLASMA DRIFT
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
ROTATING PLASMA
STABILIZATION
TEARING INSTABILITY
THERMONUCLEAR DEVICES
TOKAMAK DEVICES