CAREER: Particle Acceleration and Transport in the Solar Corona

观测已经确定，磁重联（MR）是太阳爆发现象的主要驱动力。磁共振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。了解这一过程对于预测太阳耀斑如何影响地球附近的空间天气非常重要。这项工作将使用理论建模，数值模拟和航天器观测相结合的研究MR驱动的粒子加速。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，并在国际研究生交流方案中进行合作。这项工作还支持来自该领域代表性不足的群体的早期职业教师。该项目由日地研究、激励竞争研究既定计划（EPSCoR）和等离子体物理计划共同资助，是一项综合性研究，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。该项目在以下方面推进了粒子加速和动力学理论的知识状态：（1）一种新的二阶费米加速机制，（2）电子开尔文-亥姆霍兹不稳定性（EKHI）和动力学湍流的新知识，包括逆能量级联和磁涡旋的扩展和合并;（三）在随机电场中粒子输运的创新分析处理，导致在给定湍流场的空间尺度的模拟中正确预测电子能谱，引导场;（4）关于EKHI和Alfven波湍流共振加速离子的新认识：（5）太阳耀斑电子加速中“大数”问题的新模型，将PIC模拟的范围扩展到真实的耀斑尺度;和（6）该奖项反映了NSF的法定使命，并被认为是值得支持的，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。

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.