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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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Developing and Distributing HEP Software Stacks with Spack

The Computational Science and AI Directorate at Fermilab is using Spack to support the development efforts of a large number of scientific programmers, in many independent projects and experiments. While independent, these projects share many dependencies. They are typically under continuous and fairly rapid development. They have to support deployment on diverse hardware. This is a different context than is typical for the management of HPC software, where Spack was born. To support our community, we have created a model that enables users to develop code with greater efficiency than is possible with Spack’s current development facilities. In this talk we will present: - a brief introduction to the science we support (particle physics) - how the code we work with is naturally organized into several layers of packages - how we are using Spack to manage those layers - how we leverage the layering to provide efficient support for developers, using our Spack extension “MPD”. - some suggestions for changes or additions to Spack to make such work easier.

Knoepfel, Kyle J. [Fermilab]↗
DOE OSTI2025

TA-54 Flanged Tritium Waste Container Operations, Radioactive Air Emissions Summary Volume 1: Stack Emissions & Off-Site Dose Consequence

In September 2025, pressure mitigation operations began on the four Flanged Tritium Waste Containers (FTWCs) that had been in storage at Los Alamos National Laboratory (LANL), Technical Area (TA-) 54, Area G, Building 1028. Each FTWC was opened at TA-54 and put into a stable configuration, then containers were moved to LANL’s Weapons Engineering Tritium Facility (WETF) for further processing in preparation for shipment off-site. Over the course of 13 operational days, the project had air emissions of 123 curies of tritium (hydrogen-3). The radiological dose to the hypothetical maximally exposed individual (MEI) member of the public from these emissions was 0.012 millirem. This is well within the limits established by the Environmental Protection Agency (EPA), which allows 10 millirem per year to any member of the public. Naturally occurring background radiation in Northern New Mexico averages about 300-400 millirem per year to residents. This report is intended to briefly summarize operations that took place in September and October 2025, provide documentation of the radionuclide air emissions from these operations, and summarize the off-site dose consequence to the public that resulted from these air emissions. Informal notifications addressing these areas were made via email to the EPA and NMED throughout the project, and summaries of these data were also posted on the LANL external web site 1 for FTWC operations.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Scalable Membrane Electrode Assembly Stack Production for Reliable Thermal Electrochemical Converters (SMART)

This Final Close Out Report documents all activities, progress, and results accomplished under the SMART project, funded by the Department of Energy (DOE), during Budget Period 1 (BP1), covering 10/01/2023 to 07/31/2025. Although official preaward approval was granted on 05/10/2024, contracting delays shifted the award and formal project start to 10/01/2024. In the absence of an official kick-off meeting, early interactions focused on planning for key technical challenges, particularly the design and logistics for the JTEC device test platform.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2024

A Full-Stack Exploration of Language-Based Parallelism in Fortran 2023

This poster explores native parallel features in Fortran 2023 through the lens of supporting applications with libraries, compilers, and parallel runtimes. The language revision informally named Fortran 2008 introduced parallelism in the form of Single Program Multiple Data (SPMD) execution with two broad feature sets: (1) loop-level parallelism via do concurrent and (2) a Partitioned Global Address Space (PGAS) comprised of distributed “coarray” data structures. Fortran’s native parallelism has demonstrated high performance [1] and reduced the burden of inserting what sometimes amounts to more directives than code. Several compilers support both feature sets, typically by translating do concurrent into serial do loops annotated by parallel directives and by translating SPMD/PGAS features into direct calls to a communication library. Our research focuses primarily on two questions: (1) can the compiler’s parallel runtime library be developed in the language being compiled (Fortran) and (2) can we define an interface to the runtime that liberates compilers from being hardwired to one runtime and vice versa. We are answering these questions by developing the Parallel Runtime Interface for Fortran (PRIF) [2] and the Co-Array Fortran Framework of Efficient Interfaces to Network Environments (Caffeine) [3]. Caffeine is initially targeting adoption by LLVM Flang, a new open-source Fortran compiler developed by a broad community in industry, academia, and government labs. We are also exploring the use of these features in Inference-Engine, a deep learning library designed to facilitate neural network training and inference for high-performance computing applications written in modern Fortran.

Rasmussen, Katherine↗
DOE OSTI2024

Investigation of properties of CdSeTe/Sb and Sb/CdSeTe stacks

The effect of Sb inclusion in CdSeTe thin films was examined. CdSeTe alloys were grown by co-evaporation, either on 5 nm thick electron-beam evaporated Sb layers (Sb/CdSeTe) or coated with Sb post-deposition (CdSeTe/Sb). Sb inclusion improved CdSeTe grain structure, a critical factor for device performance, with average grain size increasing from 0.6 to 1.5 μm. All samples crystallized on annealing to the cubic structure, with a change in film orientation from (111) to random or (220). The presence of Sb in CdSeTe/Sb or Sb/CdSeTe samples, however, had a limited effect on the carrier concentration compared to Sb-free samples. Time resolved photoluminescence showed Sb inclusion increased decay lifetimes, with τ1 = 0.8 ns for and τ2 = 6.9 ns for the Sb/CdSeTe sample.

14 SOLAR ENERGY↗