G8 Initiative: G8 Research Councils Initiative on Multilateral Research Funding

美国国家科学基金会授予普林斯顿大学的这一奖项，资助美国研究人员参加由八国集团研究理事会多边研究倡议通过面向全球规模问题的百亿亿次计算应用软件跨学科计划竞争性选择的项目。这是美国国家科学基金会、加拿大国家科学与工程研究委员会（NSERC）、法国国家研究局（ANR）、德国德国科学促进会（DFG）、日本科学促进会（JSPS）、俄罗斯基础研究基金会（RFBR）和英国研究委员会（RC-UK）之间的试点合作。支持在竞争基础上选出的由至少三个伙伴国家的研究人员组成的合作研究项目。轻核素的聚变形成了宇宙中能量释放的基础，它有可能被利用并作为地球上清洁和可持续的能源供应。为了建立发展聚变能所需的科学基础，一个关键的需求是及时开发一个集成的高物理保真度的磁约束聚变等离子体预测模拟能力。一个相关的核心物理挑战是理解、预测和控制由磁受限热核等离子体中不可避免的空间变化（梯度）引起的不稳定性。一个后果是湍流波动（微湍流）的发生，它可以显著增加热、粒子和动量在托卡马克装置（如ITER）中穿过限制磁场的传输速率。ITER是一个数十亿美元的国际实验装置，正在法国的卡达拉什建造，涉及代表世界一半以上的7个政府的合作伙伴关系。年代人口。对于给定的机器尺寸，微湍流会严重限制能量约束时间。S性能和经济可行性。了解并可能控制这些能量损失和实际聚变反应的自热率之间的平衡，是实现确保未来聚变发电厂实用性所需的效率的关键。湍流输运的精确计算是至关重要的，只有通过先进的模拟才能实现。目前，美国的项目使用从头算粒子胞内（PIC）全局（3D）代码来解决陀螺仪动力学理论的非线性方程，并且已经展示了超过100,000个处理器内核的出色扩展。计划将这些代码部署在参与八国集团项目的两个超级计算中心（美国的阿贡国家实验室和德国的Juelich超级计算中心），其中最先进的高性能计算系统正在运行。为了及时地产生具有最高物理保真度的模拟，预计在百亿亿次的计算将是实现计算聚变研究的最终目标所必需的。一个集成的预测模拟能力，在与实际聚变能生产相关的制度中进行适当的实验验证。

This NSF award to Princeton University funds U.S. researchers participating in a project competitively selected by the G8 Research Councils Initiative on Multilateral Research through the Interdisciplinary Program on Application Software towards Exascale Computing for Global Scale Issues. This is a pilot collaboration among the U.S. National Science Foundation, the Canadian National Sciences and Engineering Research Council (NSERC), the French Agence Nationale de la Recherche (ANR), the German Deutsche Forschungsgemeinschaft (DFG), the Japan Society for the Promotion of Science (JSPS), the Russian Foundation for Basic Research (RFBR),and the United Kingdom Research Councils (RC-UK), supporting collaborative research projects selected on a competitive basis that are comprised of researchers from at least three of the partner countries.The fusion of light nuclides forms the basis of energy release in the universe, which can potentially be harnessed and used as a clean and sustainable supply of energy on Earth. In order to build the scientific foundations needed to develop fusion energy, a key need is the timely development of an integrated high-physics-fidelity predictive simulation capability for magnetically confined fusion plasmas. An associated central physics challenge is understanding, predicting, and controlling instabilities caused by the unavoidable spatial variations (gradients) in a magnetically-confined thermonuclear plasma. One consequence is the occurrence of turbulent fluctuations (microturbulence) which can significantly increase the transport rate of heat, particles, and momentum across the confining magnetic field in a tokamak device such as ITER -- a multi-billion dollar international experimental device being built in Cadarache, France and involving the partnership of 7 governments representing over half of the world?s population. Microturbulence can severely limit the energy confinement time for a given machine size and therefore it?s performance and economic viability. Understanding and possibly controlling the balance between these energy losses and the self-heating rates of the actual fusion reaction is key to achieving the efficiency needed to help ensure the practicality of future fusion power plants. Accurate calculations of turbulent transport are vitally important and can only be achieved through advanced simulations. The current U.S. project uses ab initio particle-in-cell (PIC) global (3D) codes to solve the nonlinear equations underlying gyrokinetic theory with excellent scaling to more than 100,000 processor cores having already been demonstrated. It is planned that these codes will be deployed at the two supercomputing centres involved in this G8 project (Argonne National Laboratory in the U.S. and Juelich Supercomputing Centre in Germany), where state-of-the-art HPC systems are operative. In order to move in a timely manner to producing simulations with the highest possible physics fidelity, it is expected that computing at the exascale will be necessary to achieve the ultimate goal of computational fusion research ? an integrated predictive simulation capability that is properly validated against experiments in regimes relevant for practical fusion energy production.