Kinetic Stabilization of Tilt Disruption in Field-Reversed Configurations

The kinetic stabilization process of the tilt disruption in a field-reversed configuration is investigated by means of a three-dimensional particle simulation. For the case of no ion beam the growth rate of tilt instability decreases as the plasma beta value at magnetic separatrix beta_sp increases. This stabilization effect originates from the character of anchoring ions which exist in the vicinity of the magnetic separatrix and play a role as an "anchor" to hold the internal plasma to the external plasma. The tilt mode is also found to be stabilized by injecting an ion beam with about 20% of the ion thermal energy at the neighborhood of the null point even for small beta_sp Plasmas