Laboratory Observation of Localized Onset of Magnetic Reconnection

• Main Authors: Katz, Noam Karasov (Contributor), Egedal-Pedersen, Jan (Contributor), Fox, William R. (Contributor), Le, Ari Yitzchak (Contributor), Bonde, Jeffrey D. (Contributor), Vrublevskis, Arturs (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Plasma Science and Fusion Center (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2011-01-14T17:00:12Z.
• Subjects: Article
• Online Access: Get fulltext

Magnetic reconnection is a fundamental process in plasmas that results in the often explosive release of stored magnetic energy, but the trigger for its onset is not well understood. We explore this trigger for fast reconnection in toroidal experiments using a magnetic x-type geometry in the strong guide-field regime. We find that the onset occurs asymmetrically: the reconnection begins on one side of the torus and propagates around approximately at the Alfvén speed. The fast reconnection occurs only in the presence of a global plasma mode, which breaks the axisymmetry and enables the current at the x line to decrease sharply. A simple semiempirical model is used to describe the onset's growth rate.
United States. Dept. of Energy (Grant No. DEFG02- 06ER54878)
National Science Foundation (U.S.) and United States. Dept. of Energy (Grant No. DE-FG02- 03ER54712)
United States. Dept. of Energy. Center for Multiscale Plasma Dynamics (CMPD) (Grant No. DE-FC02-04ER54786)