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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 955 records · Page 53
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Time Resolution Characterization of 4H-SiC LGADs with a 90 Sr Source

This work presents timing measurements of 4H-SiC Low Gain Avalanche Detectors (4H-SiC LGADs) using beta particles from a 90Sr source. The 4H-SiC LGADs exhibit fast signal responses, and a time resolution of 61 ps was achieved, comparable to that of standard Si LGADs. The present limitation in the time resolution of 4H-SiC LGADs appears to stem from limited charge generation. Nevertheless, their higher voltage tolerance and faster carrier drift suggest that, with increased charge collection, their timing performance could approach or even surpass that of Si LGADs. Furthermore, these results demonstrate the strong potential of 4H-SiC LGADs as a robust platform for precision timing in future 4D tracking detectors, while also highlighting that signal charge is the dominant factor currently limiting their performance, indicating that further optimization of gain and drift structures will be essential for future development.

43 PARTICLE ACCELERATORS↗
DOE OSTI2021

Diverse Super-Resolution (diversity_SR) [SWR-21-60]

Deep learning tools for enhancing the spatial resolution of wind data. The software is developed in Python using the TensorFlow deep learning package. Models for diversity super-resolution is provided. Included in the package are pretrained models with example code/data to perform the super-resolution as well as tools of training models for different enhancement- or data-types. The super-resolution is an inherently ill-conditioned problem, with multiple high-resolution fields plausibly mapping to the same coarse field. Considitional GANs provide a framework for generating a distribution of high-resolution realizations from a given low-resolution input. Stochastic estimation is used to inform the network of the expected degree and location of sub-grid diversity. The package includes a pretrained network to generate distributions of 10x-enhanced fields of wind data.

Glaws, Andrew↗
DOE OSTI2026

Solvari SR, Simplifying Residential Solar to 1 SKU, with Extended Testing

Accelerated weathering and material compatibility testing for polymeric and asphaltic materials. NLR will be testing the durability of the polymeric materials proposed for use in the supporting structures designed by TESCI solar. This will include the bare materials and coupons attached to asphalt shingles. The exposure will be in damp heat and separately heat, humidity and UV light, all followed by mechanical evaluation. Modification 1 is an extension of the first round of testing with both a continuation of some of the same testing and addition of new testing methods and materials. The testing of materials in the condition of A3 looking at mechanical durability will be continued looking at the materials used in the mounting brackets. We will be adding in testing of the silicone adhesive to the module and of the module itself. For the mounting brackets, testing will also be conducted at multiple temperatures and humidity levels to allow for extrapolation to the field.

14 SOLAR ENERGY↗
NASA NTRS1972

Ames Research Center SR&T program and earth observations

An overview is presented of the research activities in earth observations at Ames Research Center. Most of the tasks involve the use of research aircraft platforms. The program is also directed toward the use of the Illiac 4 computer for statistical analysis. Most tasks are weighted toward Pacific coast and Pacific basin problems with emphasis on water applications, air applications, animal migration studies, and geophysics.

Poppoff, I. G.↗
NASA NTRS1972

Rb-Sr age of a Luna 16 basalt and the model age of lunar soils.

An internal isochron was determined on a small basalt fragment (sample B-1) returned from the Luna 16 mission, which yields an age of 3.42 plus or minus 0.8 b.y. and a low initial Sr87/Sr86 value. A comparison is made of the data from four lunar missions to mare sites which shows that the last period of major flooding of the mare basins is confined to a narrow time interval of only 0.55 b.y. The direct evidence of major lunar magmatic activity appears to be confined to the interval from 3.1 to 4.0 b.y. The Sr87/Sr86 values for all mare basalts are extremely primitive and lie in a rather narrow range. A diagram is given for initial Sr87/Sr86 as a function of time for all lunar rocks.

Papanastassiou, D. A.↗