IN-SITU, TIME RESOLVED SCATTERING MEASUREMENTS OF SHOCK DRIVEN NANOPOROUS FILMS

冲击驱动纳米多孔薄膜的原位时间分辨散射测量

• 批准号: 8172014
• 负责人: STEF VAN BUUREN
• 金额: $ 0.73万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8172014
• 关键词: Area; Arts; Behavior; Computer Retrieval of Information on Scientific Projects Database; Evolution; Feedback; Film; Funding; Grant; In Situ; Institution; Lasers; Measurement; Measures; Methods; Modeling; Morphology; Performance; Physics; Physiologic pulse; Process; Property; Pump; Research; Research Personnel; Resources; Shock; Solid; Source; Structure; Theoretical model; Time; United States National Institutes of Health; Work; density; energy density; insight; interest; research study

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. There is significant interest in developing a predictive understanding the behavior of shocked solids. In order to achieve this understanding, it is absolutely crucial to directly probe the controlling phenomena, in-situ and in real time. One area of keen interest, considered in this proposal, are the shock-induced collapse of the void structure in highly porous solids. Nanoporous solids are considered essential for high energy density physics experiments as well as targets for laser fusion at the National Ignition Facility. Characterizing the performance of low density materials under these extreme conditions provides crucial feedback to target designers and fabricators on the reliability of existing models and insight in developing materials with optimal properties. Recently, we have successfully developed the capability of measuring small angle x-ray scattering using a single x-ray pulse, enabling the use of pump-probe experiments to measure structural changes in-situ during a shock. In the proposed work we are applying these methods to nanofoams for the first time, and expect to answer a major question that must be resolved: How reliable are the existing theoretical models used to describe the compression of foams? We propose to characterize the morphology of nanoporous solids under high strain rate or shocked conditions, and to use these results to validate models of void evolution in these materials. Very little is currently understood about how the morphology of nanofoams responds under shock conditions and in this work we plan to quantify dynamic structural changes with a state of the art time resolved small angle x-ray scattering (TRSAXS). Ultimately, we hope to obtain a predictive capability for these materials under extreme conditions as a function of initial structure and compression dynamics. The proposed experiments would provide new insight into the details of the pore collapse process.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 有显着的兴趣，发展一个预测性的理解冲击固体的行为。为了达到这种理解，直接探测控制现象是绝对关键的，在现场和真实的时间。一个领域的强烈兴趣，在这个建议中考虑，是冲击引起的高度多孔固体中的空隙结构的崩溃。纳米多孔固体被认为是高能量密度物理实验以及国家点火装置激光聚变的目标所必需的。通过表征低密度材料在这些极端条件下的性能，可以为目标设计师和制造商提供关于现有模型可靠性的重要反馈，以及开发具有最佳性能的材料的洞察力。最近，我们已经成功地开发了测量小角度的X射线散射，使用一个单一的X射线脉冲的能力，使使用泵浦探测实验，以测量在冲击过程中原位的结构变化。在拟议的工作中，我们首次将这些方法应用于纳米泡沫，并希望回答一个必须解决的主要问题：用于描述泡沫压缩的现有理论模型的可靠性如何？我们建议在高应变率或冲击条件下表征纳米多孔固体的形态，并使用这些结果来验证这些材料中的空隙演化模型。目前对纳米泡沫的形态在冲击条件下的响应知之甚少，在这项工作中，我们计划用最先进的时间分辨小角X射线散射（TRSAXS）来量化动态结构变化。最终，我们希望在极端条件下获得这些材料的预测能力，作为初始结构和压缩动力学的函数。所提出的实验将提供新的洞察孔隙塌陷过程的细节。