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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Case Study: Leveraging GenAI to Build AI-based Surrogates and Regressors for Modeling Radio Frequency Heating in Fusion Energy Science

This work presents a detailed case study on using Generative AI (GenAI) to develop AI surrogates for simulation models in fusion energy research. The scope includes the methodology, implementation, and results of using GenAI to assist in model development and optimization, comparing these results with previous manually developed models.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2025

Portable and Adaptable Neutron Diagnostics for Advancing Fusion Energy Science Addendum

Activation detectors developed at LLNL for measuring real-time neutron fluence from fusion sources are used in the broader fusion community. The recommended fluence operating range of this diagnostic is 5x10 2 – 1x10 6 n/cm2. The upper limit on this fluence range is set by the dead time caused by data transfer between the detector and data acquisition computer. Delaying the start of counting is a possible strategy to operate these detectors in higher fluences.

42 ENGINEERING↗
DOE OSTI2020

Leading magnetic fusion energy science into the big-and-fast data lane

To crack the code of unlimited clean energy from magnetic fusion, researchers collaborate among numerous facilities that are scattered around the globe. Probing hot fusion plasmas with sophisticated diagnostics, they routinely generate fast streams of high-dimensional time-series data. We present the adaptation of a production code-base for a plasma diagnostic to the big-and-fast data lane. The new code-base is used to stream measurements, made in Korea, into a Top-15 computing facility in the US for remote analysis. We discuss software and design choices made for this new HPC-enabled scientific workflow.

Kube, Ralph↗
DOE OSTI2017

Performance Portability of HPC Discovery Science Software: Fusion Energy Turbulence Simulations at Extreme Scale

As HPC R&D moves forward on a variety of “path to exascale” architectures today, an associated objective is to demonstrate performance portability of discovery-science-capable software. Important application domains, such as Magnetic Fusion Energy (MFE), have improved modelling of increasingly complex physical systems -- especially with respect to reducing “time-to-solution” as well as “energy to solution.” The emergence of new insights on confinement scaling in MFE systems has been aided significantly by efficient software capable of harnessing powerful supercomputers to carry out simulations with unprecedented resolution and temporal duration to address increasing problem sizes. Specifically, highly scalable particle-in-cell (PIC) programing methodology is used in this paper to demonstrate how modern scientific applications can achieve efficient architecture-dependent optimizations of performance scaling and code portability for path-to-exascale platforms.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2024

Case Study: Leveraging GenAI to Build AI-based Surrogates and Regressors for Modeling Radio Frequency Heating in Fusion Energy Science

This work presents a detailed case study on using Generative AI (GenAI) to develop AI surrogates for simulation models in fusion energy research. The scope includes the methodology, implementation, and results of using GenAI to assist in model development and optimization, comparing these results with previous manually developed models.

Artificial Intelligence (cs.AI)↗
DOE OSTI2017

Brochure on Fusion Energy Sciences at the U.S. Department of Energy: The Unexpected Benefits of Harnessing the Stars.

At the center of all stars, including our sun, fusion occurs. Hydrogen and other simple elements are heated enough that their electrons have been knocked free of their atomic nuclei, forming an ensemble of positively charged ions and negatively charged electrons, known as a plasma, that can conduct electrical currents and respond to electric and magnetic fields. The science of plasmas—the fourth state of matter—is elegant, far- reaching, and impactful. Comprising over 99% of the visible universe, plasmas are also pervasive. Plasma is the state of matter of the sun’s center, corona, and solar flares. Plasma dynamics are at the heart of extraordinary galactic jets and accretion of stellar material around black holes. Plasma physics describes the processes giving rise to the aurora that vividly illuminates the far northern and southern nighttime skies. Some practical applications of plasmas include various forms of lighting, more efficient electronics and transportation, and improved medical procedures.

Source record↗
DOE OSTI2016

FY 2016 Fusion Energy Sciences (FES) Theory and Simulation Performance Target

Annual target: Predicting the magnitude and scaling of the divertor heat load width in magnetically confined burning plasmas is a high priority for the fusion program and ITER. One of the key unresolved physics issues is what sets the heat flux width at the entrance to the divertor region. Perform massively parallel simulations using 3D edge kinetic and fluid codes to determine the parameter dependence of the heat load width at the divertor entrance and compute the divertor plate heat flux applicable to moderate particle recycling conditions. Comparisons will be made with data from DIII-D, NSTX-U, and C-Mod.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2024

Development of multi-scale computational frameworks to solve fusion materials science challenges

Over the past two decades, the US-DOE has funded multiple projects that rely on high-performance computing and exascale computing platforms to accelerate scientific discoveries and address grand scientific challenges, such as harnessing fusion energy. In this article, we review in detail one of these efforts aimed at enhancing our capability to model plasma-facing materials subject to plasma and high-energy ion/neutron irradiation. The plasma surface interactions project has built a multi-scale modeling framework where many of the plasma- and high-energy ion/neutron irradiation-induced effects occurring in tungsten are explored. Here, this knowledge is used to develop atomistically-informed, high-fidelity continuum and meso-scale models that can be validated against experiments. We review the developments within this project, with attention to experimental validation efforts, and specifically highlight activities associated with: helium bubble bursting and equation of state, and hydrogen-helium interactions in tungsten; atomistically-informed model development for beryllium-tungsten material mixing; coupling of scrape-of-layer plasma, sheath and material models; and coupling of stochastic cluster-dynamics and crystal plasticity models to address radiation effects in tungsten under stress. Finally, we present how the project is preparing for future computational architectures, for instance through efforts to adapt atomistic methods to exascale computing.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Optical design and efficiency measurement of an extreme ultraviolet high-resolution spectrometer for unresolved transition array research

Understanding the structures of the unresolved transition array (UTA) observed in extreme ultraviolet (EUV) spectra from many-electron atoms is crucial for various applications, including fusion science and nanolithography. Here, to measure the fine structure of the UTA from tungsten and tin at around 5 and 13.5 nm at the Tokyo electron beam ion trap, we developed a high-resolution EUV spectrometer. The designed spectrometer achieves a resolving power of λ/dλ > 5000 at 5 and 13.5 nm. The fabricated large-area grating was experimentally examined at beamline BL5B of the UVSOR synchrotron facility to evaluate the diffraction efficiencies and their variation across the ruled area. The measured diffraction efficiencies are 0.65% ± 0.07% at 5 nm (second order) and 7.9% ± 0.2% at 13.5 nm (first order). The variation in the diffraction efficiency across the ruled area is 2.2%, 13.6%, and 10.0% in zeroth, first, and second order diffractions, respectively. The discrepancies in diffraction efficiencies between the experiments and the calculations were 5.2%, 29%, and 35% for the zeroth, first, and second diffraction orders, respectively.

47 OTHER INSTRUMENTATION↗
DOE OSTI2019

Conference Grant Report Submitted to the Office of Fusion Energy Science by the University of California, San Diego

The High Energy Density Science Association (HEDSA) in collaboration with the University of California San Diego (UCSD), hosted the High Energy-Density Science Summer School from July 30 – August 11, 2017 on the UC San Diego campus. The goal of the Summer School series is to introduce new talent to the breadth of the U.S. High Energy Density Science (HEDS) community through lectures, engaging workshops, and discussion sessions with leaders in academia and the national laboratories. The objectives are to inspire young scientists to pursue graduate and professional careers in the fields of high energy density science, teach them fundamental HED science and critical skills, and grant them the opportunity to network with leading academic and national laboratory researchers. Our focus was to attract promising early-career students from across the country.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2024

Fusion Energy Sciences Network Requirements Review: Mild-cycle Update

The US Department of Energy (DOE) Office of Science (SC) world-class research infrastructure provides the research community with premier observational, experimental, computational, and network capabilities. Each user facility is designed to provide unique capabilities to advance core DOE mission science for its sponsor SC program and to stimulate a rich discovery and innovation ecosystem. Research communities gather and flourish around each user facility, bringing together diverse perspectives. The continual reinvention of the practice of science — as users and staff forge novel approaches expressed in research workflows — unlocks new discoveries and propels scientific progress.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2017

Final Report for the FY-2017 Fusion Energy Sciences (FES) Theory and Simulation Performance Target

As stated in the language of the FY-2017 FES Theory and Simulation Performance Target, lower hybrid current drive (LHCD) will be indispensable for driving off-axis current during long-pulse operation of future burning plasma experiments including ITER. However, the experimentally demonstrated high efficiency of LHCD is not completely understood because LH waves used in these experiments are typically injected at values of the parallel (along B) phase speed v// that are much greater than the phase speed where linear electron Landau is strongest; namely at v// ~ (2.5-3)×vte, where vte = (2Te/me)1/2. Thus, these wave are expected to be only weakly damped. This turns out to be the case when the background electron temperature is of order Te ~ 3 keV and the parallel refractive index of the LH waves is n// = c/v// ~ 2, which is typical of LHCD experiments in the EAST Tokamak.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2017

Fusion Energy Sciences FY 2017 Joint Research Target (JRT) Summary Milestone Report

In support of the 2017 JRT, the DIII-D, NSTX-U and C-Mod teams performed coordinated research, focused on the subjects of dissipative divertor physics and divertor heat flux footprints. As evident in this report, good progress was made on many fronts toward assembling informed pictures of the plasma physics. The teams chose research topics that would best utilize the unique capabilities of DIII-D, NSTX and C-Mod – access to interesting divertor magnetic configurations and geometries, excellent diagnostic sets and extended parameter regimes. The research took advantage of dedicated experimental investigations on DIII-D and archived data analyses from NSTX and C-Mod – all targeted to address keys questions for tokamak power exhaust handling. DIII-D dedicated significant run time to support the 2017 JRT. This included coordinated experiments to investigate an NSTX-like, high flux expansion divertor configuration to compare its detachment response to that seen in NSTX. DIII-D implemented divertor diagnostic upgrades as well and operated with a ‘small angle slot’ divertor to investigate this ‘closed’ divertor configuration. Follow-on experiments are planned to utilize these tools. Analysis of archived data from NSTX and C-Mod was designed to exploit the wealth of information that had been collected during prior experimental campaigns. These investigations included the influence of high poloidal flux expansion on detachment onset (NSTX), magnetic flux balance dependencies of the power exhaust footprints (NSTX and C-Mod), power exhaust channel widths at poloidal magnetic fields greater than 1 Tesla, in the I-mode confinement regime and in response to divertor nitrogen seeding (C-Mod).

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2018

Fusion Energy Sciences Roundtable on Quantum Information Science, May 01-02, 2018

Quantum Information Science (QIS) is poised to revolutionize information technology, with significant impacts in many areas of science and technology. QIS includes general-purpose quantum computation, quantum simulation, quantum sensing and quantum communications. A fifth element is quantum materials, which can enable quantum computing (through physical embodiment of qubits) and which are a frontier of fundamental science in themselves.

97 MATHEMATICS AND COMPUTING↗