Keywords (Extracted from title, table of contents and abstract of thesis)
temperaturegradientdriven waves, sheared flow plasma, electrostatic waves, iontemperaturegradient, nondissipative plasma, electrontemperaturegradient, nonthermal electromagnetic fluctuations, plasma vortices, dipolar vortices, quadrupolar vortices 
Abstract By using Braginskii's transport equations for ions and Boltzmann distribution for electrons, a system of nonlinear equations governing the dynamics of lowfrequency, shortwavelength electrostatic waves in the presence of equilibrium density, temperature, magnetic field and electrostatic potential gradients has been derived. New iontemperaturegradient (ITG) driven driftdissipative modes are shown to exist. An expression for anomalous ion energy transport caused by nonthermal electrostatic fluctuations is also derived. Furthermore, possible stationary solutions of the nonlinear system are obtained in the form of double vortex. For some specific profiles of the equilibrium flow velocity, number density, temperature, and magnetic field, new type of solutions in the form of quadrupole are found to exist for a nondissipative plasma. When the plasma beta exceeds the electron to ion mass ratio, incorporation of electromagnetic effects on the ITG modes become necessary. We examined the linear and nonlinear properties of electrostatic and electromagnetic waves in the presence of iontemperature, magneticfield, density and velocity gradients. In the linear limit, a dispersion relation is obtained that admits new instabilities of drift waves. It is found that parallel velocity shear couples the electrostatic and magnetostatic modes and can cause an instability. An estimate of anomalous ion energy transport and particle flux on the basis of mixing length hypothesis is made and the results are discussed for some interesting limiting cases. The stationary solutions of the nonlinear equations without dissipation are also presented. We reexamined nonlinear mode coupling equations for finite amplitude lowfrequency electromagnetic waves in the presence of nonuniform, resistive, magnetized electronion plasma with sheared flows. The temporal behavior of the nonlinear mode coupling equations is found to be governed by eight coupled equations, which are the generalization of the Lorenz and Stenflo equations, admitting chaotic trajectories. The linear stability of the generalized LorenzStenflo system of equations is also presented under different approximations. By employing Braginskii's transport equations for electrons, we derive a system of nonlinear equations which govern the dynamics of lowfrequency short wavelength electromagnetic waves in the presence of equilibrium density, temperature, and magnetic field gradients. In the linear limit, a dispersion relation is derived and analysed. New electrontemperaturegradient (ETG) driven electromagnetic driftwave instabilities are also shown to exist. Anomalous electron energy transport caused by nonthermal electromagnetic fluctuations is derived. Possible stationary solutions of the nonlinear system are obtained in the form of spatially bounded dipolar as well as chain of vortices. In the nonlinear case, the chaotic behavior of a nonlinear dissipative system can be written in the form of well known Lorenz and Stenflo type equations. The results of our investigation should be helpful for understanding the wave phenomena in space and to kamak plasmas.
