Stability of solitary waves in a magnetized non-thermal plasma

A theoretical investigation is made of the stability of electrostatic wares in a magnetized non-ther mal plasma. The Zakharov-Kuznetsov equation (or Korteweg-de Vries equation in thr ee dimensions) for these solitary waves in this plasma system is derived, and their three-dimensional stability is studied by the small-k (long wavelength plane-wave) perturbation expansion method. The instability criterion and its growth rate depending on the magnetic field and the propagation directions of the solitary wave and its perturbation mode are discussed.