Sawtooth, Solitary, and Turbulent Waves in a Weakly Ionized Plasma

Nonlinear evolution due to many-mode couplings has been studied numerically for an inhomogeneous, magnetized, weakly ionized plasma. It is found that a sawtooth (shocklike) solution is achieved for the low range of an external parameter (weak nonlinearity), and that the solution becomes localized and solitonlike for the larger parameter range (strong nonlinearity). The parameter value differentiating the solution from a shocklike to a solitonlike shape is coincident with a critical value predicted by a theory beyond which the system becomes explosively unstable. It is further shown that the turbulent spectrum obeys a power law of k−3 which is predicted by the theory.