Magnetic Reconnection

Magnetic reconnection is a fundamental plasma physics phenomenon involved in the large scale conversion of energy stored in magnetic fields into flow and heat of the surrounding plasma. Applications include solar flares and substorms in the Earth's magnetosphere, among many others.

Past studies include work on the long-standing "Onset Problem" of magnetic reconnection. One must explain why reconnection events observed in Nature, such as solar flares, sawtooth crashes in fusion devices, and magnetospheric substorms, begin explosively. In addition to understanding the trigger mechanism which begins the reconnection process, one must also explain what prevents the trigger from occurring until a substantial buildup of free energy has taken place. The nonlinear dynamics of magnetic reconnection has been studied using analytic techniques and numerical simulations. An onset mechanism based on the bistability of reconnection has been presented and is consistent with results from laboratory experiments at VTF (MIT) and MRX (PPPL), as well as data from solar and stellar coronae.

Another project studies the scaling and properties of asymmetric magnetic reconnection, that is, reconnection between plasmas of different density and with different magnetic field strengths. Much work has been done on the shock structure, but scaling with ambient system parameters had not been performed. There are strong potential applications to reconnection at the dayside magnetopause.

Collaborators: Paul Cassak, Matthew Beidler, Colin Komar, Lucas Shepherd, Robert Baylor