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CAREER: Particle Acceleration and Transport in the Solar Corona

职业：日冕中的粒子加速和传输

基本信息

批准号：
2144324
负责人：
Haihong Che
金额：
$ 61.65万
依托单位：
University of Alabama in Huntsville
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2022
资助国家：
美国
起止时间：
2022-05-01 至 2027-04-30
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2144324&HistoricalAwards=false
关键词：
CAREER Particle Acceleration Transport Solar

项目摘要

Observations have established that magnetic reconnection (MR) is the principal driver of eruptive phenomena on the Sun. How MR accelerates charged particles in solar flares is a long-standing unsolved problem in solar physics. It is important to understand this process in order to predict how solar flares impact space weather near the Earth. This work will investigate particle acceleration driven by MR using a combination of theoretical modeling, numerical simulations, and spacecraft observations. The educational component involves mentoring of graduate students and postdocs, support for an existing summer school on space science and collaboration in an international graduate student exchange program. The work also supports an early career faculty member from an under-represented group in the field. This project is jointly funded by the Solar-Terrestrial Research, the Established Program to Stimulate Competitive Research (EPSCoR), and the Plasma Physics programs.The work is a comprehensive study aimed at substantially improving understanding of the nonlinear kinetic processes underlying particle acceleration in solar flares. This project advances the state of knowledge of particle acceleration and kinetic theory regarding (1) a novel 2nd-order Fermi-acceleration mechanism; (2) new knowledge on electron Kelvin-Helmholtz instabilities (EKHI) and kinetic turbulence including the inverse energy cascade and the expanding and merging of magnetic vortices; (3) innovative analytical treatment of particle transport in the stochastic electric field that results in the correct prediction of the electron energy spectrum in simulations given the spatial scales of turbulent fields and guide field; (4) new knowledge on ion acceleration by the resonance of EKHI and Alfven wave turbulence; (5) a new model for the “big number” problem in electron acceleration in solar flares, extending the scope from the PIC simulation scale to the size of real flares; and (6) new knowledge on particle beam development in the solar corona.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

观测已经证实，磁重联（MR）是太阳喷发现象的主要驱动因素。MR如何加速太阳耀斑中的带电粒子是太阳物理学中一个长期未解决的问题。为了预测太阳耀斑如何影响地球附近的空间天气，了解这一过程是很重要的。这项工作将结合理论建模、数值模拟和航天器观测来研究MR驱动的粒子加速度。教育部分包括指导研究生和博士后，支持现有的空间科学暑期学校，以及在国际研究生交流项目中进行合作。这项工作还支持来自该领域代表性不足群体的早期职业教师。该项目由日地研究、刺激竞争研究的既定计划（EPSCoR）和等离子体物理计划共同资助。这项工作是一项全面的研究，旨在大大提高对太阳耀斑中粒子加速的非线性动力学过程的理解。本项目在以下方面推进了粒子加速和运动理论的知识状态：(1)一种新的二阶费米加速机制；(2)关于电子Kelvin-Helmholtz不稳定性（EKHI）和动力学湍流的新认识，包括逆能量级联和磁涡的扩展和合并；(3)创新了随机电场中粒子输运的解析处理方法，在给定湍流场和引导场空间尺度的情况下，正确预测了模拟中的电子能谱；(4) EKHI和Alfven波湍流共振对离子加速的新认识；(5)建立了太阳耀斑中电子加速“大数”问题的新模型，将PIC模拟尺度扩展到实际耀斑的尺度；(6)日冕粒子束发展的新认识。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。