Study of Plasma Instabilities and Turbulence in Expanding Solar Corona

有许多基本的等离子体过程在日地物理学中具有根本的重要性。其中，太阳风在日冕中的扩张是一个突出的例子，在过去的许多年里引起了很大的理论兴趣。在过去的几十年里，许多研究人员为理解这一过程做出了重要而有价值的贡献。在本研究中，有几个相关的问题将被解决。自Parker（1958）提出日冕膨胀的第一个理论模型以来，已有许多关于动力学方法的讨论（例如，Whang和Chang, 1965； Hartle和Sturrock, 1968; Nishida, 1969； Hozer和Axford, 1970； Geiss等人，1970；Lemaire和Schere, 1971； Leer和Axford, 1972； Lemaire和Scherer， 1971）。所有其他的讨论都是基于流体力学理论，无论是单流体理论还是双流体理论。此外，他们中的大多数都强加了热各向同性的假设，这种假设似乎是由观测结果证明的，但实际上并非如此。当然，文献中也有其他出版物同时考虑了动力学模型和热各向异性的影响，但这些讨论可能没有强调日冕区域。这项工作建立在Fichtner和Fahr（1990）的观点之上，他们指出，他们的结果对波的讨论很重要，因为热各向异性会导致各种不稳定性，而这些不稳定性反过来会导致重大后果。正是在这种背景下，研究应该补充现有的理论。这项研究并没有直接涉及冠状动脉扩张。相反，它将特别关注等离子体湍流对动态过程的影响。

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.