Study On Stability Of Waves In Magnetized Dusty Plasmas

The physics of dusty plasmas has been an active branch of plasma science during the past decade. Charged dust particles exists widely in diverse environments as space plasmas, laboratory fusion devices, and low-temperature plasma applications in industry. Nevertheless, they exhibit the same or similar characteristics. Dusty plasma is defined as partially or fully ionized plasma consisting of, besides electrons and ions, (usually) negatively charged micron-sized dust particles with variable charges. The grains have completely different dynamic behavior compared with electrons and ions. Many unique self-organization phenomena in the complex plasma are affected by or originate due to the openness of the system. Take an example, the presence of dust particles, with their large inertia and small charge-to-mass ratios, give rise to new, and very low frequency modes. One example is the so-called dust acoustic wave(DAW), which attracts great attention.In this thesis, a modified Zakharov - Kuznetsov equation for small but finite amplitude dust acoustic waves in a magnetized vortex-like ion distribution dusty plasma is obtained. It seems that there is instability for a soliton under higher-order transverse perturbations in this system. There is a certain critical value 4λ₀. If the ratio of the wave length of the higher-order perturbations to the width of the soliton is larger than this critical value, the solitary wave is unstable, otherwise it is stable. The growth rate of disturbances to a solitary waves is also obtained by using multiple-scale perturbation method. The effects of the parameters of both the dusty plasma and the disturbances have been numerically discussed as well. Finally, the obliquely-propagating waves in magnetized vortex-like ion distribution dusty plasmas are investigated. A plane solitary traveling-wave solution propagating at an angleα(0≤α≤π) to the magnetic field has been considered. The effects of the parameters of both the dusty plasma and the perturbations have been numerically discussed.