Magnetic reconnection in collisionless regimes with reversed shear

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:489565

Coppi, B; Sugiyama, L E ^[1]

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1. Massachusetts Institute of Technology, Cambridge, MA (United States)

The observed persistence of plasma regimes with reversed, or nonmonotonic, q and current density profiles and the improved confinement associated with some of them suggest the conclusion that magnetic reconnection processes in collisionless plasmas are rarely strong enough to destroy these plasma configurations. We propose that this weakness should be consistent with the process that has been hypothesized to allow for the occurrence of magnetic reconnection in similar, non-reversed conditions where the resulting modes and magnetic islands are observed, that is, an underlying state of microturbulence. In those cases, the laminar collisionless driving process, the electron inertia, was far too weak to permit the formation of significant islands. Microturbulence, however, has been shown to be capable of allowing the development of a consistent instability. In the case of reversed shear configurations, a process that reduces the microturbulence, that should also be associated with the improved plasma confinement within the reversed shear region, may be responsible for the observed stability to macroscopic magnetic reconnection as well.

• OSTI ID: 489565
• Report Number(s): CONF-960354--
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COLLISIONLESS PLASMA
MAGNETIC CONFINEMENT
MAGNETIC FIELD REVERSAL
MAGNETIC ISLANDS
MAGNETIC RECONNECTION
SHEAR
TURBULENCE