Drift-kink instability induced by beam ions in field-reversed configurations

Kazumi Nishimura, Ritoku Horiuchi, Tetsuya Sato
1999 Physics of Plasmas  
A beam injection into FRC plasmas is considered to be utilized for suppressing unstable modes. The investigation by means of a three-dimensional macroscale electromagnetic particle simulation shows that a beam injection is effective to keep FRC plasmas stable against the tilt mode [1]. On the other hand, it is also found that the drift-kink instability (DKI) grows rapidly in the vicinity of the field-null line on the midplane and reaches to the saturation level at t/tA '" 2.0 -3.5 [2]. We
more » ... -3.5 [2]. We consider FRC plasmas confined by a uniform external magnetic field within the cylindrical conducting vessel. In our simulation, the spatial distribution of beam current is assumed to be in a Gaussian form. For the initial condition of particle simulation, we assume that beam ions are injected along the azimuthal direction with the toroidal velocity Vb and the temperature Tb = o. As a result, the plasma profile On the midplane of the FRC plasmas considered in our model is very similar to the Harris equilibrium. That is, a strong antiparallel magnetic field exists at the both sides of the peaked beam current, the widths of which is comparable to the typical ion Larmor radius PiO.
doi:10.1063/1.873606 fatcat:zqoobrkjrzdhbovzlxbsawqxm4