Reconnection is a transient process in essence, and causality is a key point in dealing with reconnection. The driven concept came from this viewpoint. Computer simulation is a powerful tool to understand the overall processes in a self-consistent manner. One example of global scale nonlinear processes observed in laboratory plasmas, where the driven magnetic reconnection plays important roles, is described.

The stabilization of the tilt disruption in a field-reversed configuration by an ion beam is investigated by means of a three-dimensional particle simulation. The growth rate of tilt mode decreases as the beam current increases. It is also found that the drift kink mode grows in the vicinitv of the field null line and saturates in the early phase.

Nonlinear evolution of the fast ions and the toroidicity-induced Alfv6n eigenmodes (TAEs) has been investigated with the Fokker-Planck-magnetohydrodynamic simulation. Source and slowing-down of fast ions are considered in the Fokker-Planck equation. It is found that the TAEs reach steady saturation levels for a slowing-down time comparable to the damping time. TAE bursts take place when the slowing-down time is much longer than the damping time of the TAEs and the fast-ion pressure is sufficiently high. The fast-ion distribution is globally flattened when the TAE bursts take place.

A compact toroid (CT) plasmoid injection is considered to be one of the most promising schemes for central fueling of a fusion device. However, there is the possibility that the device magnetic field leaking to the gun region (the leakage magnetic field) prevents the CT from entering the fusion device. By using magnetohydrodynamic (MHD) numerical simulations, we investigate three-dimensional dynamics of an accelerated CT in a cylindrical conductor and examine the effect of the leakage magnetic field on the CT penetration.