Numerical simulations of two-dimensional Magnetohydrodynamic (2D MHD) turbulence reveal the presence of a huge number of sites where magnetic reconnection locally occurs. The properties of this ensemble of reconnection events, that are spontaneously generated by turbulence, have been studied. The associated reconnection rates, computed as the electric field at the neutral points, are broadly di...

This paper employs an analytic reconnection model to investigate the conditions under which Hall currents can influence reconnection and Ohmic dissipation rates. It is first noted that time dependent magnetohydrodynamic systems can be analyzed by decomposing the magnetic and velocity fields into guide field and reconnecting field components. A formally exact solution shows that Hall currents ca...

The fundamental physics of magnetic reconnection in laboratory and space plasmas is reviewed by discussing results from theory, numerical simulations, observations from space satellites, and recent results from laboratory plasma experiments. After a brief review of the well-known early work, representative recent experimental and theoretical works are discussed and the essence of significant mo...

Two-dimensional, nonlinear, Hall-magnetohydrodynamical ~MHD! numerical simulations are used to investigate the scaling of the rate of forced magnetic reconnection in the so-called Taylor problem. In this problem, a small amplitude boundary perturbation is suddenly applied to a tearing stable, slab plasma equilibrium. The perturbation is such as to drive magnetic reconnection within the plasma. ...

[1] The scaling of the reconnection rate and ion and electron outflow speeds with upstream magnetic field strengths and plasma mass densities during asymmetric collisionless (Hall) reconnection without a guide field is studied using two-dimensional two-fluid simulations. The results agree with a recent theory by Cassak and Shay (2007). It is found that the normalized reconnection rate is on the...

In this work, recent advances in numerical studies of local reconnection events in the turbulent plasmas are reviewed. Recently [1], the nonlinear dynamics of magnetic reconnection in turbulence has been investigated through high resolution numerical simulations. Both uid (MHD and Hall MHD) and kinetic (HybridVlasov) 2D simulations reveal the presence of a large number of X-type neutral points,...

Magnetic reconnection is a fundamental process in a plasma that facilitates the release of energy stored in the magnetic field by permitting a change in the magnetic topology. In this paper, we present a review of the current state of understanding of magnetic reconnection. We discuss theoretical results regarding the formation of current sheets in complex three-dimensional magnetic fields and ...

Ion heating and acceleration has been studied in the well-characterized reconnection layer of the Magnetic Reconnection Experiment @M. Yamada et al., Phys. Plasmas 4, 1936 ~1997!#. Ion temperature in the layer rises substantially during null-helicity reconnection in which reconnecting field lines are anti-parallel. The plasma outflow is sub-Alfvénic due to a downstream back pressure. An ion ene...

Title of dissertation: CATASTROPHE MODEL FOR THE ONSET OF FAST MAGNETIC RECONNECTION Paul Adam Cassak Doctor of Philosophy, 2006 Dissertation directed by: Professor James Drake Department of Physics Solar flares, magnetic substorms and sawtooth crashes in fusion devices are explosive events in which magnetic reconnection facilitates the rapid release of energy stored in stressed magnetic fields...

Magnetic reconnection is a process of magnetic field topology change, which is one of the most fundamental processes happening in magnetized plasmas. In most astrophysical environments, the Reynolds numbers corresponding to plasma flows are large and therefore the transition to turbulence is inevitable. This turbulence, which can be pre-existing or driven by magnetic reconnection itself, must b...