Particle simulation study on the tilt stabilization of the FRC plasma

Ion kinetic stabilization of the FRC tilt disruption is investigated by means of three dimensional particle simulation. The growth rate of the tilting instability decreases as the parameter s-bar decreases and the instability is completely suppressed when s-bar ≅ 1, where s-bar measures the number of ion gyroradii between the magnetic separatrix line and the field-null line. It is found that this kinetic stabilization is attributed to the characteristics of the meandering ions which execute an oscillatory motion with a large amplitude around the field-null point and carry most of the ion toroidal current. (author)