Physical Review Letters -- April 21, 1997 -- Volume 78, Issue 16, pp. 3117-3120
Identification of Y-Shaped and O-Shaped Diffusion Regions During Magnetic Reconnection in a Laboratory Plasma
- Masaaki Yamada, Hantao Ji, Scott Hsu, Troy Carter, Russell Kulsrud, Yasushi Ono, and Francis Perkins
- Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New Jersey 08543
(Received 11 November 1996; revised 17 January 1997)
Two strikingly different shapes of diffusion regions are identified during magnetic reconnection in a magnetohydrodynamic laboratory plasma. The shapes depend on the third vector component of the reconnecting magnetic fields. Without the third component (antiparallel or null-helicity reconnection), a thin double-Y-shaped diffusion region is identified. In this case, the neutral sheet current profile is accurately measured to be as narrow as the order of the ion gyro-radius. In the presence of an appreciable third component (cohelicity reconnection), an O-shaped diffusion region appears and grows into a spheromak configuration.
PACS: 52.30.Jb, 94.30.Lr, 96.60.Rd
Full paper: pdf file (238 Kb).
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