CAREER: Continuum Kinetic Studies of Hydrodynamic and Magneto Hydrodynamic Instabilities

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

Observations of supernovae explosions that occur upon the death of a star have been made and documented for thousands of years. Such observations have motivated laboratory experiments to replicate astrophysical phenomena. Concurrently, there has been development of computational modeling capabilities aimed at reproducing results from both observations and experiments. The goal of this project is to conclusively address the existing discrepancies between numerical simulations and real world measurements in regimes of relevance to astrophysics. Novel numerical tools to be developed as part of this study will have broad applicability to fundamental science questions, national security, energy, and spacecraft engineering. The strongly integrated education plan will engage students from K-12 through graduate school in research and career opportunities in science, technology, engineering, and mathematics (STEM) through an online user experience. The education and outreach activities will also strive to encourage women and under-represented groups to pursue STEM careers through collaborations with the Center for the Enhancement of Engineering Diversity at Virginia Tech and minority-serving community colleges in Virginia. In high-energy-density regimes, numerical simulations have been unable to reproduce the results from experiments and observations for decades. The state-of-the-art in numerical simulations of high-energy-density astrophysical and laboratory plasmas uses fluid models, specifically radiation-hydrodynamic and radiation-magnetohydrodynamic models. Significant deficiencies in these single-fluid models include the inability to capture physics effects included in more advanced high-fidelity multi-fluid models. The missing physics can notably impact plasma transport, which may have significant anisotropies. Furthermore, the effect of non-thermal particle population on plasma transport may be missed even by most advanced fluid models. The key to matching experimental data has been to include ad hoc tunable parameters in fluid simulations. What is necessary, but has been impractical until recently due to computational limitations, are first-principles high-dimensional kinetic calculations that can address conclusively whether the discrepancies between experiments and hydrodynamic codes could be explained using kinetic physics. The present study will include first-principles kinetic calculations using a novel, continuum-kinetic, high-order accurate, and computationally efficient algorithm to study plasma dynamics and transport in the presence of hydrodynamic and magnetohydrodynamic instabilities in high-energy-density plasmas. This project will address long-standing discrepancies between high-energy-density experiments and simulations and, as a result, could significantly advance our understanding of plasma transport with implications in a number of research areas. 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.