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Results for “Engineering - Electronic and electrical engineering, Lasers”

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 19 records

Space electric power design study

The conversion of laser energy to electrical energy is discussed. Heat engines in which the laser heats the gas inside the engine through a window as well as heat engines in which the gas is heated by a thermal energy storage reservoir which has been heated by laser radiation are both evaluated, as well as the necessary energy storage, transmission and conversion components needed for a full system. Preliminary system concepts are presented and a recommended development program is outlined. It appears possible that a free displacer Stirling engine operating directly a linear electric generator can convert 65% of the incident laser energy into electricity.

Martini, W. R.↗

Space Applications Industrial Laser System (SAILS)

A program is underway to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. This workstation, called Space Applications Industrial Laser System (SAILS), will be capable of cutting and welding steel, aluminum, and Inconel alloys of the type planned for use in constructing the Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1996, will be constructed as three modules using standard Get-Away-Special (GAS) canisters. The first module holds the laser head and cooling system, while the second contains a high peak power electrical supply. The third module houses the materials processing workstation and the command and data acquisition subsystems. The laser head and workstation cansisters are linked by a fiber-optic cable to transmit the laser light. The team assembled to carry out this project includes Lumonics Industrial Products (laser), Tennessee Technological University (structural analysis and fabrication), Auburn University Center for Space Power (electrical engineering), University of Waterloo (low-g laser process consulting), and CSTAR/UTSI (data acquisition, control, software, integration, experiment design). This report describes the SAILS program and highlights recent activities undertaken at CSTAR.

Mccay, T. D.↗

Study, optimization, and design of a laser heat engine

Laser heat engine concepts, proposed for satellite applications, are analyzed to determine which engine concept best meets the requirements of high efficiency (50 percent or better), continuous operation in space using near-term technology. The analysis of laser heat engines includes the thermodynamic cycles, engine design, laser power sources, collector/concentrator optics, receiving windows, absorbers, working fluids, electricity generation, and heat rejection. Specific engine concepts, optimized according to thermal efficiency, are rated by their technological availability and scaling to higher powers. A near-term experimental demonstration of the laser heat engine concept appears feasible utilizing an Otto cycle powered by CO2 laser radiation coupled into the engine through a diamond window. Higher cycle temperatures, higher efficiencies, and scalability to larger sizes appear to be achievable from a laser heat engine design based on the Brayton cycle and powered by a CO laser.

Taussig, R. T.↗

Laser-powered lunar base

The objective was to compare a nuclear reactor-driven Sterling engine lunar base power source to a laser-to-electric converter with orbiting laser power station, each providing 1 MW of electricity to the lunar base. The comparison was made on the basis of total mass required in low-Earth-orbit for each system. This total mass includes transportation mass required to place systems in low-lunar orbit or on the lunar surface. The nuclear reactor with Sterling engines is considered the reference mission for lunar base power and is described first. The details of the laser-to-electric converter and mass are discussed. The next two solar-driven high-power laser concepts, the diode array laser or the iodine laser system, are discussed with associated masses in low-lunar-orbit. Finally, the payoff for laser-power beaming is summarized.

Costen, R.↗

Laser aircraft

The concept of a laser-powered aircraft is discussed. Laser flight would be completely compatible with existing airports and air-traffic control, with the airplane using kerosene only power, up to a cruising altitude of 9 km where the laser satellite would lock on and beam laser energy to it. Two major components make up the laser turbofan, a heat exchanger for converting laser radiation into thermal energy, and conventional turbomachinery. The laser power satellite would put out 42 Mw using a solar-powered thermal engine to generate electrical power for the closed-cycle supersonic electric discharge CO laser, whose radiators, heat exchangers, supersonic diffuser, and ducting will amount to 85% of the total subsystem mass. Relay satellites will be used to intercept the beam from the laser satellite, correct outgoing beam aberrations, and direct the beam to the next target. A 300-airplane fleet with transcontinental range is projected to save enough kerosene to equal the energy content of the entire system, including power and relay satellites, in one year.

Hertzberg, A.↗

Ion propulsion

An ion engine is a plasma thruster which produces thrust by extracting ions from the plasma and accelerating them to high velocity with an electrostatic field. The ions are then neutralized and leave the engine as high velocity neutral particles. The advantages of ion engines are high specific impulse and efficiency and their ability to operate over a wide range of input powers. In comparison with other electric thrusters, the ion engine has higher efficiency and specific impulse than thermal electric devices such as the arcjet, microwave, radiofrequency and laser heated thrusters and can operate at much lower current levels than the MPD thruster. However, the thrust level for an ion engine may be lower than a thermal electric thruster of the same operating power, consistent with its higher specific impulse, and therefore ion engines are best suited for missions which can tolerate longer duration propulsive phases. The critical issue for the ion engine is lifetime, since the prospective missions may require operation for several thousands of hours. The critical components of the ion engine, with respect to engine lifetime, are the screen and accelerating grid structures. Typically, these are large metal screens that must support a large voltage difference and maintain a small gap between them. Metallic whisker growth, distortion and vibration can lead to arcing, and over a long period of time ion sputtering will erode the grid structures and change their geometry. In order to study the effects of long time operation of the grid structure, we are developing computer codes based on the Particle-In-Cell (PIC) technique and Laser Induced Fluorescence (LIF) diagnostic techniques to study the physical processes which control the performance and lifetime of the grid structures.

Meserole, J. S.↗

Ion propulsion

An ion engine is a plasma thruster which produces thrust by extracting ions from the plasma and accelerating them to high velocity with an electrostatic field. The ions are then neutralized and leave the engine as high velocity neutral particles. The advantages of ion engines are high specific impulse and efficiency and their ability to operate over a wide range of input powers. In comparison with other electric thrusters, the ion engine has higher efficiency and specific impulse than thermal electric devices such as the arcjet, microwave, radio frequency, and laser heated thrusters and can operate at much lower current levels than the MPD thruster. However, the thrust level for an ion engine may be lower than a thermal electric thruster of the same operating power, consistent with its higher specific impulse, and therefore ion engines are best suited for missions which can tolerate longer duration propulsive phases. The critical issue for the ion engine is lifetime, since the prospective missions may require operation for several thousands of hours. The critical components of the ion engine, with respect to engine lifetime, are the screen and accelerating grid structures. Typically, these are large metal screens that must support a large voltage difference and maintain a small gap between them. Metallic whisker growth, distortion, and vibration can lead to arcing, and over a long period of time ion sputtering will erode the grid structures and change their geometry. In order to study the effects of long time operation of the grid structure, we are developing computer codes based on the particle-in-cell (PIC) technique and laser induced fluorescence (LIF) diagnostic techniques to study the physical processes which control the performance and lifetime of the grid structures.

Meserole, J. S.↗

CO2 laser-driven Stirling engine

A 100-W Beale free-piston Stirling engine was powered remotely by a CO2 laser for long periods of time. The engine ran on both continuous-wave and pulse laser input. The working fluid was helium doped with small quantities of sulfur hexafluoride, SF6. The CO2 radiation was absorbed by the vibrational modes of the sulfur hexafluoride, which in turn transferred the energy to the helium to drive the engine. Electrical energy was obtained from a linear alternator attached to the piston of the engine. Engine pressures, volumes, and temperatures were measured to determine engine performance. It was found that the pulse radiation mode was more efficient than the continuous-wave mode. An analysis of the engine heat consumption indicated that heat losses around the cylinder and the window used to transmit the beam into the engine accounted for nearly half the energy input. The overall efficiency, that is, electrical output to laser input, was approximately 0.75%. However, this experiment was not designed for high efficiency but only to demonstrate the concept of a laser-driven engine. Based on this experiment, the engine could be modified to achieve efficiencies of perhaps 25-30%.

Lee, G.↗

Unrealized Critical Lanthanide Extraction from Sea Algae Mining (UNCLE SAM): Domestic production of critical minerals from seawater

The UNCLE-SAM project, under the Biotechnologies to Ensure a Robust Supply of Critical Materials for Clean Energy program, examined the biomining applications of seaweeds for sustainable, domestic production of critical mineral feedstocks. The ocean is a vast reserve of mineralogical wealth including rare earth elements (REEs) and platinum group metal (PGMs). These elements, categorized as “critical minerals”, are used in telecommunication devices, lasers, LED lighting, turbine generators, electric car motors, jet engine alloys, and many other applications. These critical elements are increasingly vital to a thriving, efficient and sustainable society. However, only a few countries in the global market currently produce and export REEs, leading to potential geopolitical supply disruptions. Marine macroalgae, often referred to as seaweeds, bioconcentrate critical minerals from seawater, including REEs and PGMs. Marine algae cultivation can generate a significant amount of biomass with minimal freshwater, fertilizer, and land requirements. In summary, the UNCLE-SAM project successfully evaluated the technological feasibility for marine macroalgal cultivation as a feedstock for critical minerals, explored the biological capacity of different seaweeds to provide economically relevant domestic mineral production, assessed processing techniques for thermal co-conversion of seaweeds into renewable fuel and mineral feedstocks, and executed techno-economic and lifecycle assessments for identifying the most critical gaps in our current understanding to move the technology into commercially relevant deployment. Further development of this technology could transform the bioproduct and REE mining industries and catalyze the development of a more sustainable future.

58 GEOSCIENCES↗

UNrealized Critical Lanthanide Extraction from Sea Algae Mining (UNCLE SAM)

The UNCLE-SAM project, under the Biotechnologies to Ensure a Robust Supply of Critical Materials for Clean Energy program, examined the biomining applications of seaweeds for sustainable, domestic production of critical mineral feedstocks. The ocean is a vast reserve of mineralogical wealth including rare earth elements (REEs) and platinum group metal (PGMs). These elements, categorized as “critical minerals”, are used in telecommunication devices, lasers, LED lighting, turbine generators, electric car motors, jet engine alloys, and many other applications. These critical elements are increasingly vital to a thriving, efficient and sustainable society. However, only a few countries in the global market currently produce and export REEs, leading to potential geopolitical supply disruptions. Marine macroalgae, often referred to as seaweeds, bioconcentrate critical minerals from seawater, including REEs and PGMs. Marine algae cultivation can generate a significant amount of biomass with minimal freshwater, fertilizer, and land requirements. In summary, the UNCLE-SAM project successfully evaluated the technological feasibility for marine macroalgal cultivation as a feedstock for critical minerals, explored the biological capacity of different seaweeds to provide economically relevant domestic mineral production, assessed processing techniques for thermal co-conversion of seaweeds into renewable fuel and mineral feedstocks, and executed techno-economic and lifecycle assessments for identifying the most critical gaps in our current understanding to move the technology into commercially relevant deployment. Further development of this technology could transform the bioproduct and REE mining industries and catalyze the development of a more sustainable future.

09 BIOMASS FUELS↗

Grain Structure Evolution in Fe-6Si During Directed Energy Deposition

The purpose of this study is to explore the effect of additive manufacturing (AM) process variables on the grain structure of Fe-6Si, a soft-magnetic alloy used in electrical machine and grid applications. Samples were fabricated with laser engineered net shaping (LENS) with varying inter-pass timing and numbers of unidirectional passes. Here the results show that the grain structure was affected by both solidification and solid-state grain growth mechanisms. A model of the LENS process suggests that, although shorter inter-pass times encourage greater nucleation of new grains and therefore grain refinement during solidification, these conditions also help maintain high solid-state temperatures that allow for grain boundary motion to keep pace with the build rate. Grains formed under these conditions may span multiple layers, and the high-temperature gradient promotes directional growth. This new understanding of these microstructure evolution mechanisms will aid in using process conditions to control the competition between solidification and solid-state grain growth to create grain structures that may not be possible with conventional processing.

36 MATERIALS SCIENCE↗

Engineering Design Study of Laser Power Beaming for Applications on the Moon

Using a laser to send power to a photovoltaic receiver has been proposed to transmit electrical power on the moon, particularly for applications such as powering a rover in near-polar permanent-ly-shadowed regions (PSR) where solar power is not available, however detailed engineering design studies of the spacecraft for such applications has not previously been undertaken. In this work, we did an engineering design study of two applications of laser power beaming for near-term lunar ap-plications. In the first application studied, an application was studied to provide power during the lunar night for a global network of small landers spread across the lunar surface, at latitudes ranging from equatorial to near polar landing sites. We analyze a proposal to power such small landers from orbit, using a laser to beam power from an orbital power station to photovoltaic arrays on the landers that are tuned to the laser wavelength. A commercially-available high-power 1.07-µ diode-pumped fiber laser was chosen as the source. To minimize beam spread of the a spot at the required distance, a 1.5 meter optical element was provided, using a design based on the Kepler telescope. To provide power to landers at any location, three orbital stations (“beamcraft) are required, each carrying a 3-kW laser. (If the surface science platforms requiring power are only in polar locations, or converse-ly, only in near equatorial locations, only one orbital platform is needed.) The approach is seen to be feasible, and a systems analysis was completed, the concept of operations for the system out-lined and a design for the beamcraft put together. The second design study looked at surface-to-surface power beaming using the VSAT as the la-ser platform, for an application to provide power to the interior of a permanently shadowed lunar crater from a surface platform. To maximize the distance of beaming, taking into account possible surface irregularities and the short distance to the horizon of the moon, it is desirable to emplace the laser at an elevation above the surface. The Vertical Solar Array Technology (VSAT) is a NASA program developing a solar array mounted vertically on a 10-m tall mast, designed for emplacement on a Commercial Lunar Payload Services (CLPS) lander to provide 10-kW (BOL) power near the south polar region of the moon, with a target readiness date of 2028. We used this design as the starting platform and the power source for a laser power beaming station. By mounting the laser beam director at the top of the solar array mast, a viewing distance to power receivers up to 10 km is possible. Requirements for the system were to be able to provide 300 W of continuous usable power to users including CLPS landers, VIPER class rovers, or the proposed Lunar Terrain Vehicle. The specified requirement was to be able to transmit power to a distance of up to 10 km, over a design lifetime of 5 years, and fitting within a total system landed mass under 625 kg. Again, a 1.07-µ fiber laser is mounted on the deck of the lander, with laser output sent to the laser beam director by a fiber-optic cable. A 7 square meter deployable radiator keeps the laser within operating temperature limits. The beam director is based on the design of a prototype unit developed by the University of California Santa Barbara. The system beams power for 57% of the time, with 44% of the time idle (accounting for the time when the VSAT array is itself in shadow). 1595 Watts of optical power are output in the beam. Accounting for receiver efficiency and beam losses, this results in an output onto the 1.5-meter receiving photovoltaic array of 542 watts. Of this, 300 watts is directly available to the user, while 242 watts is directed to the batteries for use while the beam is not available.

laser power↗

Prospects for Nonlinear Laser Diagnostics in the Jet Noise Laboratory

Two experiments were conducted to test whether optical methods, which rely on laser beam coherence, would be viable for off-body flow measurement in high-density, compressible-flow wind tunnels. These tests measured the effects of large, unsteady density gradients on laser diagnostics like laser-induced thermal acoustics (LITA). The first test was performed in the Low Speed Aeroacoustics Wind Tunnel (LSAWT) of NASA Langley Research Center's Jet Noise Laboratory (JNL). This flow facility consists of a dual-stream jet engine simulator (with electric heat and propane burners) exhausting into a simulated flight stream, reaching Mach numbers up to 0.32. A laser beam transited the LSAWT flow field and was imaged with a high-speed gated camera to measure beam steering and transverse mode distortion. A second, independent test was performed on a smaller laboratory jet (Mach number < 1.2 and mass flow rate < 0.1 kg/sec). In this test, time-averaged LITA velocimetry and thermometry were performed at the jet exit plane, where the effect of unsteady density gradients is observed on the LITA signal. Both experiments show that LITA (and other diagnostics relying on beam overlap or coherence) faces significant hurdles in the high-density, compressible, and turbulent flow environments similar to those of the JNL.

Herring, Gregory C.↗

Identification of Surface and Near Surface Defects and Damage Evaluation by Laser Speckle Techniques

As a part of the grant activity, a laboratory was established within the Department of Electrical Engineering for the study for measurements of surface defects and damage evaluation. This facility has been utilized for implementing several algorithms for accurate measurements of defects. Experiments were conducted using simulated images and multiple images were fused to achieve accurate measurements. During the nine months of the grants when the principal investigator was transferred in my name, experiments were conducted using simulated synthetic aperture radar (SAR) images. This proved useful when several algorithms were used on images of smooth objects with minor deformalities. Given the time constraint, the derived algorithms could not be applied to actual images of smooth objects with minor abnormalities.

Gowda, Chandrakanth H.↗

LIF Testing of ETU-2 in VF-5

A visualization of the experimental setup for the Laser-Induced Fluorescence (LIF) diagnostic system applied to AEPS Engineering Test Unit 2 (ETU-2) in the Electric Propulsion and Power Laboratory's (EPPL) Vacuum Facility 5 (VF-5)

LIF↗

Highly Efficient Nd:yag Lasers for Free-space Optical Communications

A highly efficient Nd:YAG laser end-pumped by semiconductor lasers as a possible free-space optical communications source is discussed. Because this concept affords high pumping densities, a long absorption length, and excellent mode-matching characteristics, it is estimated that electrical-to-optical efficiencies greater than 5% could be achieved. Several engineering aspects such as resonator size and configuration, pump collecting optics, and thermal effects are also discussed. Finally, possible methods for combining laser-diode pumps to achieve higher output powers are illustrated.

Sipes, D. L., Jr.↗

ECE 4396 (Final Report)

In the summer of 2025, I was fortunate enough intern at Sandia National Laboratories in Albuquerque, New Mexico. I was hired into the Southwest Analysis Laboratories for Semiconductor Advancement (SALSA) intern program. In this internship, I applied my knowledge and skills in electrical engineering to conduct hardware failure analysis. I utilized various failure analyze techniques involving the use of Infrared Thermography (IRT) and Laser Scanning Microscopy (LSM) to test different Application-Specific Integrated Circuits (ASIC) chips that are available in the public market.

42 ENGINEERING↗