Collaborative Research: SHINE--Stochastic Particle Acceleration by Turbulence in Solar Flares

合作研究：SHINE——太阳耀斑中湍流的随机粒子加速

• 批准号: 0648699
• 负责人: Alexandre Lazarian
• 金额: $ 13.96万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0648699&HistoricalAwards=false
• 关键词: Collaborative; Research; SHINE; Stochastic; Particle

The observed radiation from solar flares and solar energetic particles (SEPs) indicates the presence of nonthermal particles and very hot plasmas. While it is generally believed that the source of the energy is magnetic reconnection, the origin of these high energy particles is a matter of considerable debate. Based on new observations (notably high resolution data from RHESSI), the PIs have proposed that most of the energy released is initially converted into plasma turbulence, which then accelerates particles and heats the plasma further. This team thus plans to investigate the role of anisotropic turbulence cascade and damping in the acceleration of solar plasmas. They plan to use accurate dispersion relations that go beyond simple MHD treatments in their evaluation of wave-wave and wave-particle interactions. Their goal is to incorporate these results into a solar flare model to present a self-consistent picture of flares that can be tested by observations. The Stanford PI and his associates have developed numerical codes to study particle heating, acceleration, transport, and radiation. The Wisconsin Co-PI and his group have substantial expertise in the area of magnetic plasma turbulence and have developed codes for treating turbulence in the regimes relevant to the study. Recent work by the PI and his associates has shown that turbulence can explain many features of the new observations. They expect turbulence to be present in flare plasmas and their simulations confirm this. The Co-PI has also made progress in the understanding of compressible MHD turbulence. This Stanford-Wisconsin team thus believes that incorporating the physics of turbulence generation and evolution, and its coupling with solar plasma, will now permit advances in solar flare modeling. The complementary expertise of the Stanford and Wisconsin PIs could provide the tools necessary for a breakthrough in this important problem. This research is expected to have a strong educational aspect by involving not only postdoctoral fellows and graduate students at both institutions, but also undergraduate students. The results of this research will be presented at local educational and public institutions through the auspices of Stanford's Haas Center for Public Service.

观测到的太阳耀斑和太阳高能粒子（SEP）辐射表明存在非热粒子和非常热的等离子体。 虽然人们普遍认为能量的来源是磁重联，但这些高能粒子的起源仍然存在很大争议。 根据新的观察结果（特别是来自 RHESSI 的高分辨率数据），PI 提出，释放的大部分能量最初转化为等离子体湍流，然后加速粒子并进一步加热等离子体。 因此，该团队计划研究各向异性湍流级联和阻尼在太阳等离子体加速中的作用。 他们计划在评估波-波和波-粒相互作用时使用超越简单 MHD 处理的精确色散关系。 他们的目标是将这些结果纳入太阳耀斑模型中，以呈现可通过观测进行测试的自洽耀斑图像。这位斯坦福大学首席研究员和他的同事开发了数字代码来研究粒子加热、加速、传输和辐射。 威斯康星州联合首席研究员和他的团队在磁等离子体湍流领域拥有丰富的专业知识，并开发了处理与该研究相关的湍流的代码。 首席研究员及其同事最近的工作表明，湍流可以解释新观测结果的许多特征。 他们预计耀斑等离子体中会存在湍流，并且他们的模拟证实了这一点。 Co-PI 在理解可压缩 MHD 湍流方面也取得了进展。 因此，斯坦福大学-威斯康星大学的团队相信，结合湍流产生和演化的物理学及其与太阳等离子体的耦合，现在将允许太阳耀斑建模取得进展。 斯坦福大学和威斯康星州 PI 的互补专业知识可以为这一重要问题的突破提供必要的工具。这项研究预计将具有很强的教育意义，不仅涉及两个机构的博士后研究员和研究生，还包括本科生。 这项研究的结果将在斯坦福大学哈斯公共服务中心的支持下向当地教育和公共机构展示。