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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 667 records · Page 37
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Versatile & Intelligent Biodetection via Environmental Sensing (VIBES)

Reactive health monitoring strategies during events like the COVID-19 pandemic highlighted the need for predictive, threat-agnostic diagnostics that can detect both known diseases and novel chemical or biological threats. To address this, we investigated an optical biosensor as a breath volatile organic compound (VOC) analyzer, aiming to emulate biological olfaction. We assembled and validated the device with thin film metal coated substrate-based sensors. We immobilized small biological recognition elements on the substrates and delivered controlled concentrations of target VOCs. The sensor was irradiated with a visible laser and the sensor signal was recorded. We characterized the laser performance and tested 3 recognition elements for 2 VOCs with varying concentrations (1-100 ppm). We also evaluated enhancement of the signal using nanostructures on the metal film in comparison with planar film substrate. We demonstrated detecting ethanol reliably at concentrations as low as ~2 ppm along with preliminary detection of acetone (<100 ppm). We also found several unexpected factors that influence the sensor behavior that should be addressed to further refine the device’s performance. The nanostructures were, as expected, found to amplify the sensor signals. These findings demonstrate the feasibility of the optical bio-sensing modality for breath VOC monitoring at physiologically relevant levels. This positions LLNL to develop a low-cost, scalable, broad-spectrum health monitoring capability aligned with the Early Detection thrust of the Bioresilience Mission Focus Area and attract external funding.

47 OTHER INSTRUMENTATION↗
NASA NTRS2004

Fabrication of a novel gigabit/second free-space optical interconnect - photodetector characterization and testing and system development

The time when computing power is limited by the copper wire inherent in the computer system and not the speed of the microprocessor is rapidly approaching. With constant advances in computer technology, many researchers believe that in only a few years, optical interconnects will begin to replace copper wires in your Central Processing Unit (CPU). On a more macroscopic scale, the telecommunications industry has already made the switch to optical data transmission as, to date, fiber optic technology is the only reasonable method of reliable, long range data transmission. Within the span of a decade, we will see optical technologies move from the macroscopic world of the telecommunications industry to the microscopic world of the computer chip. Already, the communications industry is marketing commercially available optical links to connect two personal computers, thereby eliminating the need for standard and comparatively slow wired and wireless Ethernet transfers and greatly increasing the distance the computers can be separated. As processing demands continue to increase, the realm of optical communications will continue to move closer to the microprocessor and quite possibly onto the microprocessor itself. A day may come when copper connections are used only to supply power, not transfer data. This summer s work marks some of the beginning stages of a 5 to 10 year, long-term research project to create and study a free-space, 1 Gigabit/sec optical interconnect. The research will result in a novel fabricated, chip-to-chip interconnect consisting of a Vertical Cavity Surface Emitting Laser (VCSEL) Diode linked through free space to a Metal- Semiconductor-Metal (MSM) Photodetector with the possible integration of microlenses for signal focusing and Micro-Electromechanical Systems (MEMS) devices for optical signal steering. The advantages, disadvantages, and practicality of incorporating flip-chip mounting technologies will also be addressed. My work began with the design and construction of a test setup for the experiment and then appropriate characterization of the test system. Specifically, I am involved in the characterization of a commercially available 1550nm wavelength, 5mW diode laser and a study of its modulation bandwidth. Commercially produced photodetectors as well as the incorporation of microwave technology, in the form of RF input and output, are used in the characterization procedure. The next stage involves the use of a probe station and network analyzer to characterize and test a series of photodetectors fabricated on a 2 inch, Indium Gallium Arsenide (InGaAs) wafer in the Branch s microlithography lab. Other project responsibilities include, but are not limited to the incorporation of a transimpedance amplifier to the photodetector circuit; a study of VCSEL technology; bit error rate analysis of an optical interconnect system; and analysis of free space divergence of the VCSEL, optical path length of the interconnect; and any other pertinent optical properties of the one gigabit per second interconnect for fabrication and testing.

Savich, Gregory R.↗
DOE OSTI2021

Asymmetric high energy dual optical parametric amplifier for parametric processes and waveform synthesis

We report on an asymmetric high energy dual optical parametric amplifier (OPA) which is capable of having either the idlers, signals, or depleted pumps, relatively phase locked at commensurate or incommensurate wavelengths. Idlers and signals can be locked on the order of 200 mrad rms or better, corresponding to a 212 as jitter at λ =2 µ m. The high energy arm of the OPA outputs a combined 3.5 mJ of signal and idler, while the low energy arm outputs 1.5 mJ, with the entire system being pumped with a 1 kHz, 18 mJ Ti:Sapphire laser. Both arms are independently tunable from 1080 nm-2600 nm. The combination of relative phase locking, high output power and peak intensity, and large tunability makes our OPA an ideal tool for use in difference frequency generation (DFG) in the strong pump regime, and for high peak field waveform synthesis in the near-infrared. To demonstrate this ability we generate terahertz radiation through two color waveform synthesis in air plasma and show the influence of the relative phase on the generated terahertz intensity. The ability to phase lock multiple incommensurate wavelengths at high energies opens the door to a multitude of possibilities of strong pump DFG and waveform synthesis.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
NASA NTRS1986

Frequency domain laser velocimeter signal processor

The features and performance parameters of the frequency domain laser velocimeter signal processor (FDSP) for examining flow phenomena are described. A candidate for replacing the standard signal processor, the FDSP can function receiving bursts of as few as 150 photons in an instantaneous mode or down to a photon resolved regime for an averaging mode. the FDSP has a nonlinear A/D converter and data storage shift registers (high speed recorder group), an elliptic digital filter bank, a controlling microprocessor and frequency and signal gain control circuits (low speed data processing group). The high speed group amplifies, digitizes, identifies and stores burst waveforms and the low speed group identifies the signal frequency within the burst after the signal passes through digital filters. The FDSP can operate in a near-autonomous mode using photon correlation techniques and requires no human intervention for calibration.

Meyers, J. F.↗
DOE OSTI2020

Thermal loading on self-seeding monochromators in x-ray free electron lasers

One approach to achieve longitudinally coherent hard X-ray free electron laser (XFEL) radiation is to introduce a single-crystal monochromator in the beam path to generate a co-propagating, time-synchronized self-seeding radiation pulse. For modern high-repetition rate XFELs, however, thermal loading on the crystal can degrade the quality of the seed pulse. To assess limitations on the maximum XFEL pulse repetition rate imposed by the seeding crystal, a comprehensive study of thermomechanical, and X-ray diffraction effects within the crystal is presented in this paper for two consecutive self-amplified spontaneous emission pulses incident on both reflective and transmissive crystal monochromators.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRSDate not supplied

Linear Array Photodiode and Data Acquisition System Development for Multi-Point Line FLDI Measurements

The continuous development and advancement of multi-point line focused laser differential interferometry (FLDI) instruments requires larger numbers of acquisition channels to make more finely spatially resolved measurements of high-frequency flow fluctuations. No current off-the-shelf system exists for these line FLDI measurements, and so a single unified system consisting of a linear array photodiode, required electronics, and a data acquisition system has been developed to enhance the measurement resolution, both spatially and temporally. A printed circuit board was developed on which the linear array photodiode is mounted for inclusion into an existing FLDI system, and amplifier breakout boards incorporate electronics to condition the signal for the data acquisition system while retaining the necessary high frequency response. The data acquisition system uses a National Instruments chassis and multiple oscilloscope modules, with a specially-designed LabVIEW user interface for laboratory and wind tunnel setup, calibration, and testing. Details regarding the development of the linear array photodiode system and the data acquisition system are provided, and systematic testing of all components is presented, culminating in a test of the system integrated into an existing line FLDI system for measurements of a turbulent jet.

Joshua M Weisberger↗
DOE OSTI2023

A versatile high-average-power ultrafast infrared driver tailored for high-harmonic generation and vibrational spectroscopy

We report on an ultrafast infrared optical parametric chirped-pulse amplifier (OPCPA), pumped by a 200-W thin-disk Yb-based regenerative amplifier at a repetition rate of 100 kHz. The OPCPA is tunable in the spectral range 1.4–3.9 μm, generating up to 23 W of < 100-fs signal and 13 W of < 200-fs idler pulses for infrared spectroscopy, with additional spectral filtering capabilities for Raman spectroscopy. The OPCPA can also yield 19 W of 49-fs 1.75- μm signal or 5 W of 62-fs 2.8- μm idler pulses with active carrier-to-envelope-phase (CEP) stabilisation for high-harmonic generation (HHG). We illustrate the versatility of the laser design, catering to various experimental requirements for probing ultrafast science.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2024

Producing entangled photon pairs and quantum squeezed states in plasmas

Plasma is capable of mediating the conversion of two pump photons into two different photons through a relativistic four-wave mixing nonlinearity. Spontaneously created photon pairs are emitted at symmetric angles with respect to the colinear pump direction, and the emission rate is largest if they have identical frequency. Thus, two orthogonally polarized pumps can produce polarization-entangled photon pairs through a millimeter-long homogeneous plasma. Here, the noise from Raman scattering can be avoided if the pump detuning differs from twice the plasma frequency. However, pump detuning exactly equal to twice the plasma frequency can significantly enhance the interaction rate, which allows for the production of strong two-mode squeezed states. Remarkably, the amplified noise from Raman scattering are correlated and hence can be suppressed in one of the output quadratures, thereby maintaining the squeezing magnitude.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2021

Forward and backward stimulated Raman scattering in multi-speckled beams: Density dependence and effects on cross-beam energy transfer

Particle-in-cell simulations of cross-beam energy transfer (CBET) between multi-speckled beams reveal a potentially prominent energy loss from forward stimulated Raman scattering (FSRS) in the amplified seed beam [Yin et al., Phys. Plasmas 26, 082708 (2019)]. In this work, an intensity scan is used to examine this energy loss in the CBET-amplified seed beam at intensities of a few times 1014 W/cm2. Electron tracers demonstrate both the trapping in the electron plasma waves that is sustained over multiple speckles and the subsequent acceleration to velocities well beyond the phase velocity. Motivated by expanding our understanding of this energy loss mechanism, we isolate the FSRS density dependence by using a 2×1014 W/cm2 pulse to scan densities between 0.06 ncr and 0.12 ncr; a spectral analysis characterizes the energy losses from scattering with the changing densities. At saturation, both greater beam attenuation is measured at the laser frequency and larger scattering FSRS angles are observed as density increases, along with a rapid transition to primarily backscatter SRS between 0.10 ncr and 0.12 ncr, earlier than predicted by linear theory. Density gradients are shown to effectively mitigate oblique FSRS and beam energy losses in the two lower density cases, whereas 0° forward scattering is primarily suppressed in the higher density cases. Finally returning to the two-beam CBET system of interest, the interplay and mitigation of the secondary instabilities at larger domain and beam spatial scales are discussed, here also examining backward stimulated Brillouin scattering.

Stark, D. J. (ORCID:0000000203642733)↗
DOE OSTI2024

Realizing Steady-State Microbunching with Optical Stochastic Crystallization

Optical Stochastic Cooling (OSC) is a state-of-the-art beam cooling technology first demonstrated in 2021 at the IOTA storage ring at Fermilab's FAST facility. A second phase of the research program is planned to run in early 2025 and will incorporate an optical amplifier to enable significantly increased cooling rates and greater operational flexibility. In addition to beam cooling, an OSC system can be configured to enable advanced control over the phase space of the beam. An example operational mode could enable crystallization, where the particles in a bunch are locked into a self-reinforcing, regular microstructure at the OSC fundamental wavelength; we refer to this as Optical Stochastic Crystallization (OSX). OSX represents a new path toward Steady-State Microbunching (SSMB), which may enable light sources combining the high brightness of a free-electron laser with the high repetition rate of a storage ring. Such a source has applications from the terahertz to the extreme ultraviolet (EUV), including high-power EUV generation for semiconductor lithography. This contribution will discuss the status of the OSC experimental program and its potential to achieve the first demonstration of SSMB during the upcoming experimental run.

Wallbank, M.↗
DOE OSTI2025

Realizing Steady-State Microbunching with Optical Stochastic Crystallization

Optical Stochastic Cooling (OSC) is a state-of-the-art beam cooling technology first demonstrated in 2021 at the IOTA storage ring at Fermilab's FAST facility. A second phase of the research program is planned to run in 2026 and will incorporate an optical amplifier to enable significantly increased cooling rates and greater operational flexibility. In addition to beam cooling, an OSC system can be configured to enable advanced control over the phase space of the beam. An example operational mode could enable crystallization, where the particles in a bunch are locked into a self-reinforcing, regular microstructure at the OSC fundamental wavelength; we refer to this as Optical Stochastic Crystallization (OSX). OSX represents a new path toward Steady-State Microbunching (SSMB), which may enable light sources combining the high brightness of a free-electron laser with the high repetition rate of a storage ring. Such a source has applications from the terahertz to the extreme ultraviolet (EUV), including high-power EUV generation for semiconductor lithography. This contribution will discuss the integration of OSX development as part of the OSC program at IOTA. The design of an accelerator lattice to enable the mechanism and associated high fidelity simulations will be shown, and a path to realizing an experimental demonstration will be discussed.

Wallbank, Michael James [Fermilab]↗
DOE OSTI2025

Steady-State Microbunching using Optical Stochastic Cooling

Optical Stochastic Cooling (OSC) is a state-of-the-art beam cooling technology first demonstrated in 2021 at the IOTA storage ring at Fermilab's FAST facility. A second phase of the research program is planned to run in 2026 and will incorporate an optical amplifier to enable significantly increased cooling rates and greater operational flexibility. In addition to beam cooling, an OSC system can be configured to enable advanced control over the phase space of the beam. An example operational mode could enable crystallization, where the particles in a bunch are locked into a self-reinforcing, regular microstructure at the OSC fundamental wavelength; we refer to this as Optical Stochastic Crystallization (OSX). OSX represents a new path toward Steady-State Microbunching (SSMB), which may enable light sources combining the high brightness of a free-electron laser with the high repetition rate of a storage ring. Such a source has applications from the terahertz to the extreme ultraviolet (EUV), including high-power EUV generation for semiconductor lithography. This contribution will discuss the integration of OSX development as part of the OSC program at IOTA. The design of an accelerator lattice to enable the mechanism and associated high fidelity simulations demonstrating the beam dynamics will be shown, and a path to realizing an experimental demonstration will be discussed.

Wallbank, Michael James [Fermilab]↗
DOE OSTI2024

Realizing Steady-State Microbunching with Optical Stochastic Crystallization

Optical Stochastic Cooling (OSC) is a state-of-the-art beam cooling technology first demonstrated in 2021 at the IOTA storage ring at Fermilab's FAST facility. A second phase of the research program is planned to run in early 2025 and will incorporate an optical amplifier to enable significantly increased cooling rates and greater operational flexibility. In addition to beam cooling, an OSC system can be configured to enable advanced control over the phase space of the beam. An example operational mode could enable crystallization, where the particles in a bunch are locked into a self-reinforcing, regular microstructure at the OSC fundamental wavelength; we refer to this as Optical Stochastic Crystallization (OSX). OSX represents a new path toward Steady-State Microbunching (SSMB), which may enable light sources combining the high brightness of a free-electron laser with the high repetition rate of a storage ring. Such a source has applications from the terahertz to the extreme ultraviolet (EUV), including high-power EUV generation for semiconductor lithography. This contribution will discuss the status of the OSC experimental program and its potential to achieve the first demonstration of SSMB during the upcoming experimental run.

43 PARTICLE ACCELERATORS↗
DOE OSTI2020

Low-threshold laser medium utilizing semiconductor nanoshell quantum dots

Colloidal semiconductor nanocrystals (NCs) represent a promising class of nanomaterials for lasing applications. Currently, one of the key challenges facing the development of high-performance NC optical gain media lies in enhancing the lifetime of biexciton populations. This usually requires the employment of charge-delocalizing particle architectures, such as core/shell NCs, nanorods, and nanoplatelets. Here, we report on a two-dimensional nanoshell quantum dot (QD) morphology that enables a strong delocalization of photoinduced charges, leading to enhanced biexciton lifetimes and low lasing thresholds. A unique combination of a large exciton volume and a smoothed potential gradient across interfaces of the reported CdS bulk /CdSe/CdS shell (core/shell/shell) nanoshell QDs results in strong suppression of Auger processes, which was manifested in this work though the observation of stable amplified stimulated emission (ASE) at low pump fluences. An extensive charge delocalization in nanoshell QDs was confirmed by transient absorption measurements, showing that the presence of a bulk-size core in CdS bulk /CdSe/CdS shell QDs reduces exciton–exciton interactions. Altogether, present findings demonstrate unique advantages of the nanoshell QD architecture as a promising optical gain medium in solid-state lighting and lasing applications.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Electron acceleration in laboratory-produced turbulent collisionless shocks

Astrophysical collisionless shocks are among the most powerful particle accelerators in the Universe. Generated by violent interactions of supersonic plasma flows with the interstellar medium, supernova remnant shocks are observed to amplify magnetic fields and accelerate electrons and protons to highly relativistic speeds. In the well-established model of diffusive shock acceleration, relativistic particles are accelerated by repeated shock crossings. However, this requires a separate mechanism that pre-accelerates particles to enable shock crossing. This is known as the ‘injection problem’, which is particularly relevant for electrons, and remains one of the most important puzzles in shock acceleration. In most astrophysical shocks, the details of the shock structure cannot be directly resolved, making it challenging to identify the injection mechanism. In this letter we report results from laser-driven plasma flow experiments, and related simulations, that probe the formation of turbulent collisionless shocks in conditions relevant to young supernova remnants. We show that electrons can be effectively accelerated in a first-order Fermi process by small-scale turbulence produced within the shock transition to relativistic non-thermal energies, helping overcome the injection problem. Our observations provide new insight into electron injection at shocks and open the way for controlled laboratory studies of the physics underlying cosmic accelerators.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2023

Moore Machine Motion Controls Refurbishment Statement of Work and Specification

Diamond Turning Machines known as “Moore” machines are used in the production of Potassium diHydrogen Phosphate (KDP) optics required for the National Ignition Facility (NIF). These machines are owned by the Department of Energy, as provided by Lawrence Livermore National Security LLC (LLNS). Moore Machines 1 and 2 are located at the Gooch & Housego (G&H) facility in Highland Heights, OH. The existing Aerotech motion controllers, motor drivers/amplifiers, input/output (I/O) hardware, control computer, software user interface, human machine interface (HMI), cabling, and encoders are beyond service life and require replacement. This Statement of Work (SoW) defines the motion control system refurbishment requirements for the Moore diamond turning machines designated Moore 1 and Moore 2. The motion controls system design shall include a motion control computer, control software, motor drive amplifiers and controllers, linear scale encoders, rotary encoders, HMI, power distribution, emergency stop (E-Stop) and interlocks, cabling, switches, solenoids, transducers, sensors, actuators, ancillary system interfaces, and related components necessary for a complete machine tool control system. The Subcontractor shall include effort to standardize systems between the two machines if reasonably possible.

42 ENGINEERING↗
DOE OSTI2023

Magnetostrictive materials for enhanced sensors and electronic components

Magnetostriction is a property of magnetic materials that causes them to change their shape or dimensions proportional to their magnetization. Low-cost, mechanically robust magnetostrictive sensors would be valuable for a wide range of applications across the DOE and national security mission space, such as monitoring the internal conditions of pipelines, rapidly detecting high-impedance faults in power lines (e.g. trees touching power lines), or enhancing implantable systems for the human body. Dilute doping (<1 at.%) of rare earth elements (REE) has been shown to amplify the magnetostriction. Furthermore, alloy processing by rapid cooling from high temperature tends to result in texturing and therefore greater magnetostriction values, which bodes well for developing advanced manufacturing approaches significantly less expensive than single crystal growth. The goal of this effort was to develop robust, low-cost magnetostrictive materials compatible with advanced manufacturing techniques to exploit the rapid cooling of these approaches while retaining the ability to produce fully dense structures. To be useful as a sensor or actuator the coercivity of the material needs to be minimized so that there is minimal magnetic hysteresis. Employing a small scale laser powder bed fusion (L-PBF) system, specimens of Fe-Ga-Ce were built from alloy powder which had a magnetostriction of 289 ppm along the build direction and 197 ppm perpendicular to the build direction. These values are not far from the 310-350 ppm observed in single crystals of Fe-Ga. The results of the series of samples run suggest this is a very promising route for REE doping to higher levels, especially if the powders can be produced using far from equilibrium approaches such as ultrasonic atomization. The promising results from applying additive manufacturing techniques to these materials, particularly the inexpensive Fe-Al system, has potential for inexpensive high-performing magnetostrictive parts producible at large scales for low-cost sensors.

36 MATERIALS SCIENCE↗
NASA NTRS1998

Electro-Optic Lightning Detector

Electric field measurements are fundamental to the study of thunderstorm electrification, thundercloud charge structure, and the determination of the locations and magnitudes of charges deposited by lightning. Continuous field observations can also be used to warn of impending electrical hazards. For example, the USAF Eastern Range (ER) and NASA Kennedy Space Center (KSC) in Florida currently operate a ground-based network of electric field mill sensors to warn against lightning hazards to space vehicle operations/launches. The sensors provide continuous recordings of the ambient field. Others investigators have employed flat-plate electric field antennas to detect changes In the ambient field due to lightning. In each approach, electronic circuitry is used to directly detect and amplify the effects of the ambient field on an exposed metal conductor (antenna plate); in the case of continuous field recordings, the antenna plate is alternately shielded and unshielded by a grounded conductor. In this work effort, an alternate optical method for detecting lightning-caused electric field changes is Introduced. The primary component in the detector is an anisotropic electro-optic crystal of potassium di-hydrogen phosphate (chemically written as KH2PO4 (KDP)). When a voltage Is placed across the electro-optic crystal, the refractive Indices of the crystal change. This change alters the polarization state of a laser light beam that is passed down the crystal optic axis. With suitable application of vertical and horizontal polarizers, a light transmission measurement is related to the applied crystal voltage (which in turn Is related to the lightning caused electric field change). During the past two years, all critical optical components were procured, assembled, and aligned. An optical housing, calibration set-up, and data acquisition system was integrated for breadboard testing. The sensor was deployed at NASA Marshall Space Flight Center (MSFC) in the summer of 1998 to collect storm data. Because solid-state technology is used, future designs of the sensor will be significantly scaled down In physical dimension and weight compared to the present optical breadboard prototype. The use of fiber optics would also provide significant practical improvements.

Koshak, William J.↗