ECLIPSE: Ultrafast Ionization, Heating, Thermalization and Constriction of High-Pressure Nanosecond Pulsed Discharge Plasmas

该奖项支持一种新的大气压放电等离子体测量技术的实施。大气压等离子体——一种部分电离的气体——有许多潜在的应用，包括通过气体清洗去除挥发性有机化合物、内燃机的稀薄点火和高速流动的控制。扩展和扩大大气压等离子体解决社会需求的潜力的能力目前受到我们以可控和可重复的方式产生这些等离子体的能力的限制。更好地了解大气压脉冲等离子体放电不稳定性发生的机制是改善这些过程控制的关键。该项目将进行最先进的激光诊断，并辅以数值模拟来研究不稳定性。该项目还将支持为小学高年级学生开发动手等离子体实验，并在2025年国际等离子体化学研讨会上为本科生提供网络和指导会议。本研究项目旨在通过开发一套超快光学诊断系统，在纳秒级时间尺度上研究从部分电离大气压放电到完全电离热火花放电的快速转变机制。该研究将通过对超快电离和热化的定量分析，为纳秒重复脉冲放电（nrp）的等离子体物理学提供新的见解。一个重要的目标是测试提出强耦合现象在观测到的等离子体加热中的作用的理论模型。此外，将利用nrp中遇到的大范围电离度和等离子体温度来评估几种光学诊断在部分和完全电离等离子体状态下的适用性。这项研究的结果有望在电子动力学、加热和热化机制方面带来新的见解，这些机制是导致大气压等离子体不稳定性发生的原因。该项目由卢森堡国家研究基金与卢森堡科学技术研究所合作实施。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award supports implementation of a novel measurement technique for atmospheric pressure discharge plasmas. Atmospheric pressure plasma - a partially ionized gas - has many potential applications, including the removal of volatile organic compounds through gas cleaning, lean ignition of combustion engines, and control of high-speed flows. The capability to extend and broaden the potential of atmospheric pressure plasmas for addressing societal needs is currently limited by our ability to generate these plasmas in a controlled and reproducible manner. Better understanding of the mechanisms responsible for the occurrence of instabilities in atmospheric pressure pulsed plasma discharges is key to improving control of these processes. This project will perform state-of-the-art laser diagnostics complemented with numerical simulations to investigate the instabilities. This project will also support the development of hands-on plasma experiments for upper elementary school students and implementation of a networking and mentoring session for undergraduate students at the 2025 International Symposium on Plasma Chemistry.This research project aims to investigate the mechanisms of the fast transition from partially ionized atmospheric pressure discharges to fully ionized thermal spark discharges on nanosecond time scales by developing a suite of ultrafast optical diagnostics. The study will produce new insights in the plasma physics of nanosecond repetitively pulsed discharges (NRPs) with quantitative analysis of ultrafast ionization and thermalization. An important goal is to test theoretical models proposing a role of strongly coupled phenomena in the observed plasma heating. In addition, the large range of ionization degrees and plasma temperatures encountered in NRPs will be leveraged to assess the applicability of several optical diagnostics in the partially and fully ionized plasma regimes. The outcomes of this study are expected to lead to new insights on electron kinetics, heating and thermalization mechanisms responsible for the occurrence of instabilities in atmospheric pressure plasmas. The project is performed in collaboration with the Luxembourg Institute of Science & Technology supported by the Luxembourg National Research Fund.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.