Path Integral Monte Carlo Simulations of Dense Plasma

致密等离子体的路径积分蒙特卡罗模拟

• 批准号: 1640776
• 负责人: Burkhard Militzer
• 金额: $ 0.27万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1640776&HistoricalAwards=false
• 关键词: Path; Integral; Monte; Carlo; Simulations

Understanding the theoretical properties of materials in the warm dense matter (WDM) and dense plasma regimes is a central goal in the development of key energy technologies, such as advanced nuclear reactors and inertial confined fusion, shock physics, plasma science, and stockpile stewardship. The project has developed an innovative new technique to simulate dense plasmas of second-row material elements for the first time. The project will use the Blue Waters leadership system to apply this new technique to a number of key materials in order to provide guidance to shock wave experiments and establish benchmarks for other theoretical approaches. The project proposes to simulate a set of materials on a grid of temperature-density points in order to derive the equation of state (EOS) under plasma conditions and in the regime of WDM. Results from this project will be of immeasurable importance to the designers at the National Ignition Facility (NIF) and at other high-energy-density-physics facilities. Students will be extensively involved with the project, which advances the NSF mission to support basic research that may contribute to the nation?s prosperity.To study the WDM regime, the project will combine a novel PIMC simulations with standard, Kohn-Sham density functional molecular dynamics (KS-DFMD) simulations, which are more efficient at lower temperatures. While KS-DFMD has been used to accurately predict the structure of many solids and liquids up to temperatures on the order of 100,000 K, it is not applicable at much higher temperaturesbecause the number of partially occupied electronic orbitals reaches intractably large numbers. The alternate method, orbital-free density functional molecular dynamics (OF-DFMD) yields inaccurate EOS results because no existing free energy functional has been developed. Collaborators at Department of Energy (DOE) national labs will use the PIMC EOS data both as comparisons to existing semi-empirical, EOS-generating schemes, and as inputs for continuum radiation hydrodynamics simulations. The project aims to establish an efficient pipeline from PIMC to macroscopic continuum studies of materials response. An emphasis will be placed on benchmarking such methods for plasmas of heavy elements at very high temperatures (~100 eV) and low densities that are generated when Hohlraum radiation heats the ablator material in indirect drive laser experiments.

了解热致密物质 (WDM) 和致密等离子体体系中材料的理论特性是先进核反应堆和惯性约束聚变、冲击物理、等离子体科学和库存管理等关键能源技术发展的核心目标。 该项目开发了一种创新的新技术，首次模拟第二排材料元素的致密等离子体。该项目将利用Blue Waters领导系统将这项新技术应用到一些关键材料上，以便为冲击波实验提供指导，并为其他理论方法建立基准。该项目建议在温度密度点网格上模拟一组材料，以便导出等离子体条件和 WDM 状态下的状态方程 (EOS)。该项目的结果对于国家点火装置（NIF）和其他高能量密度物理设施的设计者来说具有不可估量的重要性。学生将广泛参与该项目，该项目推进了 NSF 的使命，即支持可能有助于国家繁荣的基础研究。为了研究 WDM 体制，该项目将结合新颖的 PIMC 模拟与标准 Kohn-Sham 密度泛函分子动力学 (KS-DFMD) 模拟，在较低温度下效率更高。虽然 KS-DFMD 已被用来准确预测温度高达 100,000 K 量级的许多固体和液体的结构，但它不适用于更高的温度，因为部分占据的电子轨道的数量达到了难以处理的大量。另一种方法，无轨道密度泛函分子动力学 (OF-DFMD) 会产生不准确的 EOS 结果，因为尚未开发出现有的自由能泛函。能源部 (DOE) 国家实验室的合作者将使用 PIMC EOS 数据与现有的半经验 EOS 生成方案进行比较，并作为连续辐射流体动力学模拟的输入。该项目旨在建立一条从 PIMC 到材料响应宏观连续研究的有效管道。重点将放在对在间接驱动激光实验中黑腔辐射加热烧蚀材料时产生的极高温度（~100 eV）和低密度重元素等离子体的方法进行基准测试。