Study of Plasma Instabilities and Turbulence in Expanding Solar Corona

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There are numerous basic plasma processes which are of fundamental importance in solar-terrestrial physics. Among these, the expansion of the solar wind in solar corona is an outstanding example which has attracted a great deal of theoretical interest during the past many years. In the last several decades, many researchers have made important and valuable contributions to the understanding of this process. In this research, there are several relevant problems which will be addressed. Since the first theoretical model of coronal expansion proposed by Parker (1958), there have been many discussions (e.g., Whang and Chang, 1965; Hartle and Sturrock, 1968; Nishida, 1969; Hozer and Axford, 1970; Geiss et al., 1970; Lemaire and Schere, 1971; Leer and Axford, 1972; Lemaire and Scherer, 1971) utilized on a kinetic approach. All other discussions are based on hydrodynamic theory, whether one-fluid theory or two-fluid theory was used. Furthermore, most of them have imposed the assumption of thermal isotropy which seems to be justifiable by observational results but is actually not. Of course, there are other publications in the literature in which both kinetic models and effects of thermal anisotropy have been considered, but these discussions may not emphasize the coronal region. This work builds on the view of Fichtner and Fahr (1990) who remarked that their results can be important for the discussion of waves, because thermal anisotropy can result in a variety of instabilities which should in turn lead to significant consequences. It is in this context that the studies should complement the existing theories. This study does not directly address the coronal expansion. Rather, it will pay special attention to the effects of plasma turbulence on the dynamic process.