CAREER: Massively Parallel Simulation of Multiscale Dynamics and Plasma Heating in Alfvenic Turbulence

随机磁波动在实验室、太空和天体物理等离子体中无处不在。Alfvenic乱流的非线性动态演化涉及不同时空尺度，在等离子体加热、粒子加速以及星际和星际介质中质量、动量和能量的输运中起着重要作用。了解阿尔芬尼湍流的基本等离子体物理原理最近被国家研究委员会（NRC）确定为未来十年太阳和空间物理学研究的关键挑战之一。在这个项目中，通过物理模型、数值算法的最新进展以及并行计算机速度和容量的显著提高，大规模的阿尔芬尼湍流动力学模拟将被用来研究从大尺度到小尺度的光谱级联的物理过程以及导致等离子体加热的相关能量耗散。本研究还将涉及基础等离子体物理学中的许多重要课题，例如波粒共振、有限拉莫尔半径效应和可压缩性对阿尔夫尼湍流级联和耗散的影响。波粒非线性和波波非线性将被同等对待并加以描述。研究了亚回旋频率阿尔芬波随机加热离子的可能性。拟议的项目将利用空间等离子体物理学、磁聚变科学和计算科学之间的交叉研究兴趣。在磁聚变研究中开发的先进计算工具，如大规模平行回旋动力学粒子在细胞中的模拟，将被引入到空间等离子体研究中。将与能源部先进计算科学发现计划（SciDAC）的研究人员进行密切合作。拟议的预算将支持一名博士后研究员和一名研究生撰写博士论文，并将帮助在加州大学欧文分校建立一个先进的等离子体模拟项目。该提案的首席研究员将提供一个培训和教育计划，将最先进的科学计算纳入物理课程。学生将学习大规模并行计算来解决现实世界的问题。通过参与提议的等离子体湍流模拟，将提供实际操作培训。本课程面向所有科学与工程院系的学生，在这些院系中，并行计算已成为不可或缺的研究工具。一个并行计算实验室将利用PI现有的启动基金来开发并行计算、数据分析和高级可视化的创新算法，用于教学和研究。该项目的教育和研究方面都将被整合到加州大学欧文分校最近提出的一个跨学科计算科学中心。

Random magnetic fluctuations are ubiquitous in laboratory, space, and astrophysical plasmas. The nonlinear, dynamical evolution of Alfvenic turbulence involving disparate spatial-temporal scales plays an important role in plasma heating, particle acceleration, and transport of mass, momentum, and energy in the interplanetary and interstellar medium. Understanding the basic plasma physics principles of Alfvenic turbulence has recently been identified by the National Research Council (NRC) as one of the key challenges in the next decade of research in solar and space physics. In this project, large scale kinetic simulations of Alfvenic turbulence enabled by recent advances in physics models, numerical algorithms, and the dramatically increased speed and capacity of parallel computers, will be utilized to study the physical processes underlying the spectral cascade from large to small scales and the associated energy dissipation leading to plasma heating. This study will also address many important subjects in basic plasma physics, e.g., the effects of wave-particle resonances, finite Larmor radius effects, and compressibility on the cascade and dissipation of Alfvenic turbulence. The wave-particle nonlinearity and wave-wave nonlinearity will be treated on an equal footing and be delineated. The possibility of stochastic ion heating by sub-cyclotron frequency Alfven waves will also be investigated. The proposed project will leverage cross-cutting research interests between space plasma physics, magnetic fusion science, and computational sciences. Advanced computational tools developed in magnetic fusion research, such as massively parallel gyrokinetic particle-in-cell simulations, will be introduced to space plasma research. Close collaboration will be undertaken with researchers in the Department of Energy's Scientific Discovery through Advanced Computing (SciDAC) Initiative. The proposed budget will support a postdoctoral researcher and a graduate student working on a Ph.D. thesis, and will help establish an advanced plasma simulation program at the University of California, Irvine. The Principal Investigator of this proposal will provide a training and education program that will incorporate state-of-the-art scientific computing in the physics curriculum. The students will learn massively parallel computation for solving real-world problems. Hands-on training will be provided through participation in the proposed plasma turbulence simulation. The course will be open to students from all science and engineering departments where parallel computing becomes an indispensable research tool. A parallel computing lab will be constructed using the PI's existing startup fund to develop innovative algorithms for parallel computing, data analysis, and advanced visualization in both instruction and research. Both the education and research aspects of the project will be integrated into an Interdisciplinary Center for Computational Science recently proposed at the University of California, Irvine.