Collaborative Research: CDI-Type II: Cyber-Enabled Studies of Complexity in Nanodusty Plasmas

“纳米尘埃等离子体”是一种电离气体，在这种气体中，直径只有几到几十纳米的粒子成核并生长。这些等离子体展示了物理系统中复杂性的所有特征。随着粒子的成核和长大，它们变得越来越带电，深刻地影响着等离子体，并在纳米粒子云和等离子体之间启动了一系列现在不可预测的非线性耦合。它们具有实用价值，因为纳米颗粒是半导体加工过程中的主要污染源，而且由于使用等离子体来合成纳米颗粒，用于从光伏到癌症治疗的广泛应用。在该项目中，将开发一个网络基础设施，以支持纳米尘埃等离子体数值模型的开发。有了这个网络基础设施，这些高度复杂的系统中迄今尚未解决的现象将被研究。该项目涉及一项合作，将推进几个不同的科学和工程领域，汇集化学反应等离子体和等离子体传输、粒子成核和生长、气溶胶动力学和计算化学的计算模型方面的专业知识。它利用明尼苏达超级计算研究所的工作人员和资源，以及太平洋西北和阿贡国家实验室的超级计算机设施，并与桑迪亚国家实验室合作开发混合颗粒-流体模型的并行计算技术。将开发的网络平台将建立在混合等离子体设备模型(HPEM)的基础上，该模型由其中一个等离子体设备开发，通过实施物理和化学模块的层次结构来解决粒子成核和生长以及气溶胶动力学的复杂性。利用HPEM现有的工业用户基础，该项目具有强大的技术转让组成部分，包括可能与工业合作伙伴进行商业化。该项目还具有国际视野，与法国的两个研究小组合作。该项目将开发纳米尘埃等离子体的数值模型，以及一个网络基础设施，以促进这些模型并使这些新工具普遍可用。该项目将产生有史以来第一个数值模型，自我一致地解释所有这些相互作用的现象：粒子在多维等离子体中的成核、生长和充电；纳米粒子的传输；等离子体化学；电子和离子动力学；以及纳米粒子在等离子体上的集体相互作用。这类模型的开发是一项具有挑战性的任务，由于缺乏关于小星团的性质和反应性的所需基础数据，以及真实的等离子体系统通常是三维的事实，这一点更加突出。从物理和化学的角度来看，解决这些问题是雄心勃勃的，因为从物理和化学的角度来看，人们对这些问题知之甚少；从计算的角度来看，因为涉及的范围很广，具有强耦合的相互作用的子系统和非线性行为，所以解决这些问题是雄心勃勃的。能够精确模拟真实纳米尘埃等离子体的网络基础设施的开发将标志着一个重大的范式转变。参与该项目的研究生和博士后将在一个跨学科的环境中工作，该环境连接着工程和科学的文化。该项目包括开发一个网络基础设施，供学术界和国家实验室的研究人员使用，通过软件许可将技术转让给行业，以及开展国际合作。通过开发基于网络的交互式图形用户界面、实时3-D可视化和大规模并行计算，该项目将改变纳米尘埃等离子体的研究，有利于研究人员增进对基础知识的了解，有利于半导体行业制定避免纳米颗粒污染的策略，并创造用于光伏和癌症治疗等应用的工程纳米颗粒。这是一个基于网络的发现和创新计划奖，由CISE董事会的计算和通信基础司、材料研究司和国际科学与工程办公室的数学科学司共同资助。

"Nanodusty plasmas" are ionized gases in which particles only a few to tens of nanometers in diameter nucleate and grow. These plasmas exhibit all of the hallmarks of complexity in physical systems. As particles nucleate and grow they become increasingly charged, profoundly affecting the plasma and setting in motion a set of nonlinear couplings between the nanoparticle cloud and the plasma which are now unpredictable. They are of practical interest, because nanoparticles are a major source of contamination in semiconductor processing and because of the use of plasmas to synthesize nanoparticles for a wide variety of applications, ranging from photovoltaics to cancer treatment. In this project a cyber infrastructure will be developed that will underpin the development of numerical models of nanodusty plasmas. With this cyber infrastructure, heretofore unresolved phenomena in these highly complex systems will be investigated.The project involves a collaboration that will advance several different fields of science and engineering, bringing together expertise in computational modeling of chemically reacting plasmas and plasma transport, particle nucleation and growth, aerosol dynamics and computational chemistry. It draws on staff and resources of the Minnesota Supercomputing Institute and supercomputer facilities at Pacific Northwest and Argonne National Laboratories, and involves collaboration with Sandia National Laboratories on the development of computational techniques for parallelization of hybrid particle-fluid models. The cyber platform to be developed will build upon the Hybrid Plasma Equipment Model (HPEM), developed by one of the PIs, by implementing a hierarchy of physics and chemistry modules to address the complexity of particle nucleation and growth and aerosol dynamics. Leveraging the HPEM's existing industrial user base, the project has a strong component of technology transfer, including possible commercialization with an industrial partner. The project also has an international dimension, collaborating with two research groups in France.The project will develop numerical models of nanodusty plasmas as well as a cyber infrastructure to facilitate these models and make these new tools generally available. The project will produce the first-ever numerical models that self-consistently account for all of these interacting phenomena: particle nucleation, growth and charging in a multi-dimensional plasma; nanoparticle transport; plasma chemistry; electron and ion kinetics; and the collective mutual effects of nanoparticles on a plasma. The development of such models is a challenging undertaking, made more so by the paucity of needed fundamental data on properties and reactivities of small clusters, and by the fact that real plasma systems are typically three-dimensional. Tackling these problems is ambitious from the viewpoint of physics and chemistry, many aspects of which are poorly understood, and from the computational viewpoint, as vast ranges of length and time scales are involved, with strongly coupled interacting subsystems and nonlinear behavior. The development of a cyber infrastructure that enables accurate simulations of real nanodusty plasmas will mark a major paradigm shift.Graduate students and postdocs involved in the project will work in an interdisciplinary environment that bridges the cultures of engineering and science. The project includes the development of a cyber infrastructure to be made available to researchers in academia and national labs, transfer of technology to industry through software licensing, and international collaborations. Through the development of interactive Web-based graphical user interfaces, real-time 3-D visualization, and massively parallel computing, the project will transform the study of nanodusty plasmas, with benefits to researchers in advancing fundamental understanding, to the semiconductor industry in developing strategies to avoid nanoparticle contamination, and to the creation of engineered nanoparticles for applications such as photovoltaics and cancer treatment.This is a Cyber-Enabled Discovery and Innovation Program award and is co-funded by the Division of Computing and Communication Foundations in the CISE directorate, the Division of Materials Research and the Division of Mathematical Sciences in the MPS directorate and the Office of International Science and Engineering.