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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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Time-resolved imaging of microscale dynamics in laser drying of silicon wafers
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Large-eddy simulations of the NACA23012 airfoil with laser-scanned ice shapes
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The effect of laser scanning strategy on NiTi shape memory alloys processed by laser powder bed fusion
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Development of computational framework for titanium alloy phase transformation prediction in laser powder-bed fusion additive manufacturing
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Laser calibration system for time of flight scintillator arrays
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Pointing stabilization of 140 mJ, 10 Hz UV laser for Laser-Assisted Charge Exchange
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Fast spatial laser beam modulation for improved process control in Laser Powder Bed Fusion
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A novel approach to the deposition of Co-Mo-Cr-Si coating on Haynes 282 by laser fusion and laser remelting
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Nonadiabatic Dynamics in a Continuous Circularly Polarized Laser Field with Floquet Phase-Space Surface Hopping
Non-adiabatic chemical reactions involving continuous circularly polarized light (cw CPL) have not attracted as much attention as dynamics in unpolarized/linearly polarized light. However, including circularly (in contrast to linearly) polarized light allows one to effectively introduce a complex-valued time-dependent Hamiltonian, which offers a new path for control or exploration through the introduction of Berry forces. Here, we investigate several inexpensive semiclassical approaches for modeling such nonadiabatic dynamics in the presence of a time-dependent complex-valued Hamiltonian, beginning with a straightforward instantaneous adiabatic fewest-switches surface hopping (IA-FSSH) approach (where the electronic states depend on position and time), continuing to a standard Floquet fewest switches surface hopping (F-FSSH) approach (where the electronic states depend on position and frequency), and ending with an exotic Floquet phase-space surface hopping (F-PSSH) approach (wherethe electronic states depend on position, frequency, and momentum). Using a set of model systems with time-dependent complex-valued Hamiltonians, we show that the Floquet phase- space adiabats are the optimal choice of basis as far as accounting for Berry phase effects and delivering accuracy. Furthermore, the F-PSSH algorithm sets the stage for modeling nonadiabatic dynamics under strong externally pumped circular polarization in the future.
A new class of focusing crystal shapes for Bragg spectroscopy of small, point-like, x-ray sources in laser produced plasmas
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Parametric Finite Element Analysis of Naturally Corroded Steel Specimens Using 3D Surface Laser Scans
Corrosion is considered a uniform thickness reduction design guideline of the maritime industry. However, additionally, the corroded and irregular morphology of the surface affects the steel's load-bearing capacity and its impact on the strength and elongation behaviour of the steel is not yet fully understood. These effects on the local behaviour of steel structures under tensile loading were investigated with tensile tests on naturally corroded steel specimens and nonlinear finite element simulations including the corroded surface morphology with a uniform surface idealation. The models also include the deformed specimen shape. The developed approach led to highly accurate parametric finite element models predicting the ultimate tensile strength and longitudinal position of fracture. The results show that all included aspects are essential for accurate simulations, while solely the maximum available surface resolution was not as decisive.
In situ characterization of tensile behavior of laser rapid solidified Al–Si heterogeneous microstructures
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Corrigendum: An accurate and efficient laser-envelope solver for the modeling of laser-plasma accelerators Plasma Phys. Control. Fusion 60 014002
Abstract not provided.