Study of Plasma Instabilities and Turbulence in Expanding Solar Corona

膨胀日冕中等离子体不稳定性和湍流的研究

• 批准号: 9111684
• 负责人: Ching-Sheng Wu
• 金额: $ 11.5万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-11-01 至 1995-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9111684&HistoricalAwards=false
• 关键词: Study; Plasma; Instabilities; Turbulence; Expanding

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.

有许多基本的等离子体工艺， 在日地物理学中的重要性。 之间 这些，太阳风在日冕中的膨胀是一个 这是一个很好的例子，吸引了很多人。 多年来的理论研究。 在过去 几十年来，许多研究人员已经做出了重要的， 对理解这一过程作出了宝贵贡献。 在 本研究有几个相关问题， 处理。 自从第一个日冕膨胀的理论模型 由帕克（1958）提出，有许多讨论 (e.g., Whang和Chang，1965年; Hartle和Sturrock，1968年; Nishida， 1969; Hozer和Axford，1970; Geiss等人，1970年;勒梅尔和 Schere，1971; Leer和Axford，1972; Lemaire和谢勒，1971） 利用动力学方法。 所有其他讨论都基于 无论是单流体理论还是双流体理论 理论被使用。 此外，其中大多数国家还实行了 热各向同性的假设似乎是合理的， 观察结果，但实际上不是。 当然也有 文献中的其他出版物，其中动力学模型 和热各向异性的影响已被考虑，但这些 讨论可以不强调冠状区域。 这项工作建立在Fichtner和法尔（1990）的观点之上 他说，他们的研究结果对 波的讨论，因为热各向异性可以导致一个 各种各样的不稳定性，这反过来又会导致重大的 后果 正是在这种情况下，研究报告应 补充现有的理论。 这项研究并不直接 解决日冕扩张问题 相反，它将支付特别 注意等离子体湍流对动态 过程