Laboratory Observation of Electron Phase-Space Holes during Magnetic Reconnection
Abstract
We report the observation of large-amplitude, nonlinear electrostatic structures, identified as electron phase-space holes, during magnetic reconnection experiments on the Versatile Toroidal Facility at MIT. The holes are positive electric potential spikes, observed on high-bandwidth (∼2GHz) Langmuir probes. Investigations with multiple probes establish that the holes travel at or above the electron thermal speed and have a three-dimensional, approximately spherical shape, with a scale size ∼2mm. This corresponds to a few electron gyroradii, or many tens of Debye lengths, which is large compared to holes considered in simulations and observed by satellites, whose length scale is typically only a few Debye lengths. Finally, a statistical study over many discharges confirms that the holes appear in conjunction with the large inductive electric fields and the creation of energetic electrons associated with the magnetic energy release.
- Publication:
-
Physical Review Letters
- Pub Date:
- December 2008
- DOI:
- 10.1103/PhysRevLett.101.255003
- Bibcode:
- 2008PhRvL.101y5003F
- Keywords:
-
- 52.35.Sb;
- 52.35.Vd;
- Solitons;
- BGK modes;
- Magnetic reconnection