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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 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Scaling blackbody laser to high powers

Lasers pumped by solar heated blackbody cavities have potential for multimegawatt power beaming in space. There are two basic types of blackbody lasers; cavity pumped and transfer system. The transfer system is judged to be more readily scalable to high power. In this system, either N2 or CO is heated by the blackbody cavity then transferred into the laser cavity where CO2 is injected. The N2-CO2 system was demonstrated, but probably has lower efficiency than the CO-CO system. The characteristics of potential transfer laser systems are outlined.

Deyoung, R. J.↗
DOE OSTI2023

Experimental demonstration of >20 kJ laser energy coupling in 1-cm hydrocarbon-filled gas pipe targets via inverse Bremsstrahlung absorption with applications to MagLIF

Laser propagation experiments using four beams of the National Ignition Facility to deliver up to 35 kJ of laser energy at 351 nm laser wavelength to heat magnetized liner inertial fusion-scale (1 cm-long), hydrocarbon-filled gas pipe targets to ~keV electron temperatures have demonstrated energy coupling >20 kJ with essentially no backscatter in 15% critical electron density gas fills with 0–19 T applied axial magnetic fields. The energy coupling is also investigated for an electron density of 11.5% critical and for applied field strengths up to 24 T at both densities. This spans a range of Hall parameters 0 < ω ce τ ei ≲ 2, where a Hall parameter of 0.5 is expected to reduce electron thermal conduction across the field lines by a factor of 4–5 for the conditions of these experiments. At sufficiently high applied field strength (and therefore Hall parameter), the measured laser propagation speed through the targets increases in the measurements, consistent with reduced perpendicular electron thermal transport; this reduces the coupled energy to the target once the laser burns through the gas pipe. In conclusion, the results compare well with a 1D analytic propagation model for inverse Bremsstrahlung absorption.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS2010

Corrosion-Resistant Container for Molten-Material Processing

In a carbothermal process, gaseous methane is passed over molten regolith, which is heated past its melting point to a temperature in excess of 1,625 C. At this temperature, materials in contact with the molten regolith (or regolith simulant) corrode and lose their structural properties. As a result, fabricating a crucible to hold the molten material and providing a method of contact heating have been problematic. Alternative containment approaches use a large crucible and limit the heat zone of the material being processed, which is inefficient because of volume and mass constraints. Alternative heating approaches use non-contact heating, such as by laser or concentrated solar energy, which can be inefficient in transferring heat and thus require higher power heat sources to accomplish processing. The innovation is a combination of materials, with a substrate material having high structural strength and stiffness and high-temperature capability, and a coating material with a high corrosion resistance and high-temperature capability. The material developed is a molybdenum substrate with an iridium coating. Creating the containment crucible or heater jacket using this material combination requires only that the molybdenum, which is easily processed by conventional methods such as milling, electric discharge machining, or forming and brazing, be fabricated into an appropriate shape, and that the iridium coating be applied to any surfaces that may come in contact with the corrosive molten material. In one engineering application, the molybdenum was fashioned into a container for a heat pipe. Since only the end of the heat pipe is used to heat the regolith, the container has a narrowing end with a nipple in which the heat pipe is snugly fit, and the external area of this nipple, which contacts the regolith to transfer heat into it, is coated with iridium. At the time of this reporting, no single material has been found that can perform the functions of this combination of materials, and other combinations of materials have not proven to be survivable to the corrosiveness of this environment. High-temperature processing of materials with similar constituencies as lunar regolith is fairly common. The carbo-thermal process is commonly used to make metallurgical-grade silicon for the semiconductor and solar-cell industries.

Stern, Theodore G.↗
DOE OSTI2020

Laser-induced digital oxidation for copper-based flexible photodetectors

Copper oxide compounds (Cu x O) with bandgaps of 1.3–2.1 eV (CuO) and 2.1–2.6 eV (Cu 2 O) have been investigated as promising p-type semiconducting materials. Cu x O is generally obtained by deposition or thermal oxidation, but those methods are not optimal for flexible substrates. Furthermore, additional patterning steps are required to fabricate devices. In this work, we present an easy, controllable method to fabricate a metal-semiconductor-metal (MSM) photodetector using laser-induced oxidation of a thin Cu film. After laser irradiation, the Cu film is heated under ambient conditions, and this leads to a thermal oxidation reaction, in which Cu oxide is monolithically formed in the Cu film and a Cu-Cu x O-Cu MSM structure is produced. Since the laser offers localized heating, an arbitrary CuxO pattern can be written in the Cu film by spatially controlled heating. In addition, by optimizing the heating time, the laser-induced oxidation can be successfully performed even on a flexible substrate. To study the laser-induced oxidation, we examined the correlation between laser parameters and the oxidation pattern and analyzed the composition using scanning electron microscopy, Raman spectroscopy, and X-ray photoemission spectroscopy. Furthermore, we measured the transient photoresponse and employed scanning photocurrent microscopy to investigate the mechanism of carrier transport behavior.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Modeling the Interaction of Laser-Produced Proton Beams with Matter

A major goal of this project is to significantly increase our understanding of isochoric heating of matter using laser produced proton beams, and the associated high energy density (HED) and warm dense matter (WDM) regimes generated. This will benefit research fields such as planetary science, fusion energy, plasma physics, and material science. For example, it will enhance our understanding of WDM properties of iron and silica under conditions encountered in planetary interiors and diagnostic components in fusion devices exposed to high fluxes of energetic plasma ions. The project is motivated by recent experiments that irradiated Si targets with proton beams generated by the 20 TW-laser at the SLAC MEC end-station. The HED/WDM states are probed using the 50 fs hard X-rays available in the 3rd harmonic of the LCLS. As part of this project, results from the phase contrast X-ray imaging, which shows the generation of compression waves that produces rear surface spallation, are compared with results from the 3D multi-physics multi- material code, PISALE, that combines Arbitrary Lagrangian-Eulerian (ALE) hydrodynamics with Adaptive Mesh Refinement (AMR). This comparison required modifications to several physics models in the PISALE (Pacific Island Structured-AMR with ALE) code. An important aspect of this project is the continued training of graduate students in HED physics and in conducting complex multiphysics simulations.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS1982

Containerless high temperature property measurements by atomic fluorescence

Laser induced fluorescence techniques were developed for the containerless study of high temperature processes, material properties, levitation, and heating techniques for containerless earth-based experimentation. Experiments were performed in which fluorescence of atomic aluminum, mercury, or tungsten were studied. These experiments include measurements of: (1) Al atom evaporation from CW CO2 laser heated and aerodynamically levitated sapphire and alumina spheres, and self-supported sapphire filaments, (2) Al atom reaction with ambient oxygen in the wake of a levitated specimen, (3) Hg atom concentrations in the wake of levitated alumina and sapphire spheres, relative to the ambient Hg atom concentration, (4) Hg atom concentrations in supersonic levitation jets, and (5) metastable, electronically excited W atom concentrations produced by evaporation of an electrically heated tungsten filament.

Nordine, P. C.↗
DOE OSTI2023

Development of an in situ ion irradiation scanning electron microscope

An in situ ion irradiation scanning electron microscope (I 3 SEM) has been developed, installed, and integrated into the Ion Beam Laboratory at Sandia National Laboratories. The I 3 SEM facility combines a field emission, variable pressure, scanning electron microscope, a 6 MV tandem accelerator, high flux low energy ion source, an 808 nm-wavelength laser, and multiple stages to control the thermal and mechanical state of the sample observed. The facility advances real-time understanding of materials evolution under combined environments at the mesoscale. As highlighted in multiple examples, this unique combination of tools is optimized for studying mesoscale material response in overlapping extreme environments, allowing for simultaneous ion irradiation, implantation, laser bombardment, conductive heating, cooling, and mechanical deformation.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2020

Single-Crystal Growth and Room-Temperature Magnetocaloric Effect of X-Type Hexaferrite Sr 2 Co 2 Fe 28 O 46

X-type hexaferrites have been receiving considerable attention due to their promising applications in many magnetic-electronic fields. However, the growth of single-crystal X-type hexaferrite is still a challenge. Herein we reported, for the first time, the preparation of single crystal X-type hexaferrite Sr 2 Co 2 Fe 28 O 46 (Sr 2 Co 2 X) with high-quality and large size using floating-zone method with laser as the heating source. The crystals show rhombohedral symmetry with space group of R-3m (No. 166, a = 5.8935(1) Å and c = 83.7438(17) Å). Co 2+ and Fe 3+ oxidation states were confirmed by the X-ray absorption near-edge spectroscopy. The prepared Sr 2 Co 2 X exhibits a spin reorientation transition from easy-cone to easy-axis at T 2 of 343 K and a ferrimagnetism–paramagnetism transition at Curie temperature (TC) of ~743 K. The spin reorientation transition was accompanied by magnetocaloric effect (MCE). Both conventional and inverse MCEs were observed near T 2 with a magnetic field applied along the c-axis. The maximum value of the magnetic entropy change along the c-axis was evaluated to be 1.1 J/kg·K for a magnetic field change of 5 T.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Kinetic Landau-fluid closures of non-Maxwellian distributions

New kinetic Landau-fluid closures, based on the cutoff Maxwellian distribution, are derived. A special static case is considered (the frequency ω=0). In the strongly collisional regime, our model reduces to Braginskii's heat flux model, and the transport is local. In the weak collisional regime, our model indicates that the heat flux is non-local and recovers the Hammett–Perkins model while the value of the cutoff velocity approaches to infinity. We compare the thermal transport coefficient χ of Maxwellian, cutoff Maxwellian and super-Gaussian distribution. The results show that the reduction of the high-speed tail particles leads to the corresponding reduction of the thermal transport coefficient χ across the entire range of collisionality, more reduction of the free streaming transport toward the weak collisional regime. In the collisionless limit, χ approaches to zero for the cutoff Maxwellian and the super-Gaussian distribution but remains finite for Maxwellian distribution. χ is complex if the cutoff Maxwellian distribution is asymmetric. The Im(χ) approaches to different convergent values in both collisionless and strongly collisional limit, respectively. It yields an additional streaming heat flux in comparison with the symmetric cutoff Maxwellian distribution. Furthermore, due to the asymmetric distribution, there is a background heat flux q0 though there is no perturbation. Furthermore, the derived Landau-fluid closures are general for fluid moment models, and applicable for the cutoff Maxwellian distribution in an open magnetic field line region, such as the scape-off-layer of Tokamak plasmas, in the thermal quench plasmas during a tokamak disruption, and the super-Gaussian electron distribution function due to inverse bremsstrahlung heating in laser-plasma studies.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2020

The Center for Integrated Nanotechnologies (CINT)

The Center for Integrated Nanotechnologies (CINT) offers world-leading scientific expertise and specialized capabilities to create, characterize, and integrate nanostructured materials at a range of length scales, from nano- to meso-scale. CINT helps scientists perform cutting-edge research in the areas of nanoscience and nanotechnology, providing FREE ACCESS for nonproprietary research. CINT facilities are open to the international research community, including government, academic, and industry researchers. One of CINT's core research areas is in-situ S/TEM experiments. Early capabilities focused on electrical and electrochemical property measurements of materials during high-resolution imaging. More recently, the staff has expanded the available techniques to include gaseous environments (ETEM), liquid-cell, mechanics, ion irradiation, laser ablation, cryogenic, heating, and air-free transfer. In-situ investigations have focused on coupled structure-property measurements on real materials, with the CINT user community expanding many of the in-situ method developments.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Effects of a strong applied magnetic field on relativistic laser-plasma interactions

This project investigated the role played by strong external magnetic fields in laser-matter interactions at relativistic intensities and their impact of resulting high-energy density phenomena. The regimes that can benefit from currently available or soon to be available magnetic fields have been identified. The applications of this project include laser-driven ion acceleration and laser-driven plasma heating.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2025

ElementLIBS User's Guide: An operational aid for use and development

Laser-Induced Breakdown Spectroscopy or LIBS is a rapid, in-situ analytical technique where a laser of known energy is pulsed at the surface of an analyte. The laser pulse rapidly heats a localized area to many thousand degrees Kelvin, ablating part of the analyte and turning it into a plasma. As the plasma cools, excited atoms return to a ground state with known emission energies. This emitted energy is captured by various spectrometers and provides a spectrum of the emitted energies and intensities. This spectrum can be analyzed to provide the elemental composition of a sample by using known emission lines and relative abundance. ElementLIBS was developed for the SciAps hand-held LIBS model Z300 but will work with any model that provides a LIBS spectrum of similar resolution. The Z300 has an integrated resolution of 1/30 nm with a range of approximately 180nm – 960nm, providing an output spectrum of 23431 pixels across three spectrometers. These criteria are only provided as a reference, as the software was designed to work with any size spectrum, provided the input file is of the correct format and the models were developed using the same framework. If spectra of varying dimensions are used, the software will fail without warning and unusual events could occur.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1972

High sensitivity infrared 10.6 micrometer heterodyne receiver development

The results are presented for a study on the design of an infrared 10.6-micrometer quantum-noise-limited optical receiver subsystem. Performance measurements of the HgCdTe photomixer preamplifier combination were carried out for photomixer temperatures up to 152 K and a photomixer frequency response of up to 420 MHz was obtained. Results of temperature and bias cycling of HgCdTe photomixers are reported. Design considerations for an operational 10.6 micrometer heterodyne receiver are presented. These consist of design data on required laser LO illumination, heat load levels for photomixer cooler, photomixer uniformity and the effects of photomixer impedance match on receiver sensitivity. Analysis and measurements of 10.6 micrometer heterodyne detection in an extrinsic photoconductive (p-type) HgCdTe photomixer are also presented.

Source record↗
NASA NTRS1980

Stark cell optoacoustic detection of constituent gases in sample

An optoacoustic detector for gas analysis is implemented with Stark effect cell modulation for switching a beam in and out of coincidence with a spectral line of a constituent gas in order to eliminate the heating effect of laser energy in the cell as a source of background noise. By using a multiline laser, and linearly sweeping the DC bias voltage while exciting the cell with a multiline laser, it is possible to obtain a spectrum from which to determine the combinations of excited constituents and determine their concentrations in parts per million.

Margolis, J. S.↗
NASA NTRS1980

Laser power beaming for rocket propulsion and airbreathing propulsion

The developing technology of laser power beaming is introduced, and two systems are used as examples of the capabilities of the laser for beamed energy. In the first system, the potential of the laser to power flight systems ranging from hypersonic air-breathing launch vehicles to commercial jet transports is examined. Attention is given to the possibility of an air-breathing propulsion which offers the promise of a global air transportation network independent of kerosene and powered by solar energy. In addition, consideration is given to a new type of rocket propulsion based on the laser's ability to concentrate coherent laser energy to high power densities. Focused laser beams would heat the propellants directly to produce specific impulses approaching ion and MHD rocket levels, and would do so without the burden of a heavy electrical power supply.

Hertzberg, A.↗
NASA NTRS1990

Measuring Irradiance Over Large Areas

Relatively simple experimental technique yields data processed, via straightforward mathematical model, into map of thermal irradiance over large area. Imaging infrared radiometer makes temperature map of sheet. Irradiance distribution at sheet location then deduced from temperature map. Used to obtain rapid measurements of incident-flux distribution over broad spectral range at specific locations relative to such heat sources as infrared heat lamps or lasers.

Glazer, Stuart D.↗
NASA NTRS1992

Axial-Gap Induction Motor For Levitated Specimens

Motor does not obscure view of specimen. Axial-gap induction motor applies torque to rotate electrostatically or electromagnetically levitated specimen of metal. Possible applications include turning specimens for uniform heating under focused laser beams and obtaining indirect measurements of resistivities or of surface tensions in molten specimens.

Sridharan, Govind↗