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: 0648750
• 负责人: Vahe Petrosian
• 金额: $ 31.56万
• 依托单位: Stanford University
• 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 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0648750&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）的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是一个相当大的争论。基于新的观测（特别是RHESSI的高分辨率数据），PI提出，大部分释放的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。他们计划在波-波和波-粒子相互作用的评估中使用超越简单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，以提供一个可以通过观测进行测试的自洽耀斑图像。斯坦福大学的PI和他的同事们已经开发出了研究粒子加热、加速、传输和辐射的数字代码。威斯康星州的合作PI和他的团队在磁等离子体湍流领域拥有丰富的专业知识，并开发了用于处理与研究相关的制度中的湍流的代码。PI及其同事最近的工作表明，湍流可以解释新观测的许多特征。他们预计耀斑等离子体中存在湍流，他们的模拟证实了这一点。Co-PI在可压缩MHD湍流的理解方面也取得了进展。因此，这个斯坦福-威斯康星团队认为，将湍流产生和演化的物理学及其与太阳等离子体的耦合结合起来，现在将允许太阳耀斑建模的进步。斯坦福大学和威斯康星州的PI的互补专业知识可以为在这个重要问题上取得突破提供必要的工具。这项研究预计将有一个强大的教育方面，不仅涉及博士后研究员和研究生在这两个机构，但也本科生。这项研究的结果将通过斯坦福大学的哈斯公共服务中心的赞助在当地的教育和公共机构进行介绍。