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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 NTRS2013

Synthesis and Spectroscopy of Large Carbon Molecules with Ames' COSmIC Facility in Support of NASA's Space Missions

We present and discuss the unique characteristics and capabilities of the laboratory facility, COSmIC, that was developed at NASA Ames to generate, process and analyze interstellar and planetary analogs in the laboratory. COSmIC stands for Cosmic Simulation Chamber and is dedicated to the study of molecules and ions under the low temperature and high vacuum conditions that are required to simulate interstellar, circumstellar and planetary physical environments in space. COSmIC integrates a variety of state-of-the-art instruments that allow forming, processing and monitoring simulated space conditions for planetary, circumstellar and interstellar materials in the laboratory. COSmIC is composed of a Pulsed Discharge Nozzle (PDN) expansion that generates a free jet supersonic expansion coupled to two ultrahigh-sensitivity, complementary in situ diagnostics: a Cavity Ring Down Spectroscopy (CRDS) system for photonic detection and a Reflectron Time-Of-Flight Mass Spectrometer (ReTOF-MS) for mass detection. Recent, unique, laboratory astrophysics results that were obtained using the capabilities of COSmIC will be discussed, in particular the progress that have been achieved in monitoring in the laboratory the formation of solid gains from their gas-phase molecular precursors in environments as varied as stellar/circumstellar outflow and planetary atmospheres. Plans for future, next generation, laboratory experiments on cosmic molecules and grains in the growing field of laboratory astrophysics will also be addressed.

Spectroscopy↗
DOE OSTI2025

Building workflows for an interactive human-in-the-loop automated experiment (hAE) in STEM-EELS

Exploring the structural, chemical, and physical properties of matter on the nano- and atomic scales has become possible with the recent advances in aberration-corrected electron energy-loss spectroscopy (EELS) in scanning transmission electron microscopy (STEM). However, the current paradigm of STEM-EELS relies on the classical rectangular grid sampling, in which all surface regions are assumed to be of equal a priori interest. However, this is typically not the case for real-world scenarios, where phenomena of interest are concentrated in a small number of spatial locations, such as interfaces, structural and topological defects, and multi-phase inclusions. One of the foundational problems is the discovery of nanometer- or atomic-scale structures having specific signatures in EELS spectra. Herein, we systematically explore the hyperparameters controlling deep kernel learning (DKL) discovery workflows for STEM-EELS and identify the role of the local structural descriptors and acquisition functions in experiment progression. In agreement with the actual experiment, we observe that for certain parameter combinations the experiment path can be trapped in the local minima. We demonstrate the approaches for monitoring the automated experiment in the real and feature space of the system and knowledge acquisition of the DKL model. Based on these, we construct intervention strategies defining the human-in-the-loop automated experiment (hAE). This approach can be further extended to other techniques including 4D STEM and other forms of spectroscopic imaging. The hAE library is available on Github at https://github.com/utkarshp1161/hAE/tree/main/hAE.

Pratiush, Utkarsh [Univ. of Tennessee, Knoxville, ↗
DOE OSTI2024

Scanning tunneling spectroscopy of surface-oxidized Gallium-stabilized δ -phase plutonium

Here, the first contiguous experimental scanning tunneling spectroscopy (STS) measurements of the electronic structure of a plutonium (Pu) surface are presented and compared to current theoretical results. The experiments took place under UHV conditions, for which Pu is known to retain a native surface oxide. The STS data shows that no band gap is observable at room temperature. Theoretical calculations predict that bulk Pu oxides are semiconductors, but the spectral results for the cleaned Pu surface native oxide under UHV conditions could be better characterized as that of a semimetal.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2025

Directed Synthesis of Gold Nanoparticle Superstructures Using Self-Assembling Peptoids Containing Metal-Bonding N-Heterocyclic Carbenes

N-Heterocyclic carbene (NHC) ligands, with strong metal-binding affinity, offer a robust platform for constructing organic–inorganic nanohybrids with high stability and tunable properties. However, achieving precise structural control in a simple manner remains challenging. Here, we report a one-pot synthesis of nanohybrids using self-assembling peptoids functionalized with histidine-2-ylidene, which simultaneously enable peptoid assembly and NHC–metal binding. Histidine-2-ylidene-functionalized peptoids were designed to self-assemble and provide NHC binding sites, while AuNPs served as the inorganic component due to NHCs’ strong affinity for gold surfaces. The resulting peptoid-NHC@AuNPs form well-defined vesicles that are characterized by UV–vis spectroscopy, X-ray photoelectron spectroscopy, and electron microscopy. Importantly, the vesicle size and morphology can be tuned via the peptoid sequence or environmental conditions. Further experiments highlight the crucial role of the NHC sites in the formation and stabilization of these nanohybrids. This modular strategy offers a versatile route to fabricating functional NHC-based nanohybrids for potential applications in sensing.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

High Pressure Synthesis of Rubidium Superhydrides

Through laser-heated diamond anvil cell experiments, we synthesize a series of rubidium superhydrides and explore their properties with synchrotron x-ray powder diffraction and Raman spectroscopy measurements, combined with density functional theory calculations. Upon heating rubidium monohydride embedded in H 2 at a pressure of 18 GPa, we form RbH 9 − I , which is stable upon decompression down to 8.7 GPa, the lowest stability pressure of any known superhydride. At 22 GPa, another polymorph, RbH 9 − II is synthesised at high temperature. Unique to the Rb-H system among binary metal hydrides is that further compression does not promote the formation of polyhydrides with higher hydrogen content. Instead, heating above 87 GPa yields RbH 5 , which exhibits two polymorphs ( RbH 5 − I and RbH 5 − II ). All of the crystal structures comprise a complex network of quasimolecular H 2 units and H − anions, with RbH 5 providing the first experimental evidence of linear H 3 − anions. Published by the American Physical Society 2025

Kuzovnikov, Mikhail A.↗
NASA NTRS1976

Future directions for beam-foil spectroscopy

The beam-foil source has proved to be so useful for the study of atomic energy levels that it is almost trivial to propose a variety of new experiments involving new elements, higher energies, a broader wavelength range, shorter time intervals, pulsed beams, different targets, and new configurations in geometry or external fields. However, what is perhaps not so trivial is to propose experiments for which there is a specific purpose, experiments from which a novel kind of information might be expected. It is from this latter point of view that the author shall talk about experiments which seem to offer unusual opportunities to learn new things about atoms.

Bashkin, S.↗
NASA NTRS1977

Geology orbiter comparison study

Instrument requirements of planetary geology orbiters were examined with the objective of determining the feasibility of applying standard instrument designs to a host of terrestrial targets. Within the basic discipline area of geochemistry, gamma-ray, X-ray fluorescence, and atomic spectroscopy remote sensing techniques were considered. Within the discipline area of geophysics, the complementary techniques of gravimetry and radar were studied. Experiments using these techniques were analyzed for comparison at the Moon, Mercury, Mars and the Galilean satellites. On the basis of these comparative assessments, the adaptability of each sensing technique was judged as a basic technique for many targets, as a single instrument applied to many targets, as a single instrument used in different mission modes, and as an instrument capability for nongeoscience objectives.

Cutts, J. A. J.↗
NASA NTRS1976

Terrestrial bodies orbiter, LUNAR - A system for detailed global measurements of a planet's properties

The NASA Lunar Polar Orbiter, to be launched by a Delta vehicle in 1980, is designed to perform a global exploration of such moon properties as the gravity field, figure, and surface composition, as well as a lunar resource survey. The paper reviews the mission, spacecraft, and data system concepts in terms of baseline mission sequence, choice of orbits, spacecraft configuration requirements, mission sequence requirements and data system and operations. Scientific experiments planned for the Orbiter mission include geophysical altimetry and gravity experiments, heat flow experiment, magnetic field experiments, measurements of the moon's natural gamma-ray spectrum, X-ray fluorescence of lunar surface materials, sunlight reflectance spectroscopy, and spectro-stereo imaging. Characteristics of instruments designed for use in these investigations are examined. Through the use of advanced sensors and data-system techniques, coupled with well-developed spacecraft systems, the mission promises to return a very large quantity and variety of lunar data at a cost comparable with that of simpler missions in the past.

Burke, J. D.↗
NASA NTRS1993

A test of the applicability of independent scattering to high albedo planetary regoliths

We show that 'independent scattering' is a useful approximation for high albedo particles whose size and packing density are similar to typical particles in the lunar regolith. Laboratory measurements of the intensity and linear polarization of light scattered from a laboratory sample of glass spheres of know size and composition are compared to radiative transfer calculations of the same observable quantities. Mie scattering is integrated over the size distribution of the particles to determine the mean phase and polarization functions, or phase matrix, of the particle. Assuming that the particles scatter independently, the 'doubling method' is used to rigorously calculate multiple scattering in an optically thick layer of these anisotropically scattering particles. All of the major features 'predicted' in the calculated intensity (double peaks at small phase angles) and polarization (negative branch at small phase angles, large positive peak near 20 degrees phase, and small polarization elsewhere) are observed in the laboratory measurements, with good quantitative agreement indicated at phase angles less than 90 degrees. Even though the particles are supported by physical contact with each other in the sample, as are the particles in planetary regoliths, the independent scattering calculation yields a good approximation to both the intensity and polarization. The physical parameters input to the calculation are only the size distribution of the particles and their complex index of refraction (composition). Significant advantages of this approach are that the phase matrix is calculated from basic physical principles and both the intensity and polarization are determined simultaneously. This model may have broad applications to the interpretation of photometry, spectroscopy, and polarimetry of the icy regoliths of high albedo satellites. The intent of this effort is to perform a controlled experiment that tests the utility of the independent scattering assumption

Goguen, J. D.↗
NASA NTRS1994

Simultaneous soft and hard X-ray spectroscopy of AM Herculis with EXOSAT: Discovery of photospheric absorption features

We present 0.1-10 keV spectroscopic observations of AM Herculis obtained with the Transmission Grating Spectrometers and Medium Energy experiments on EXOSAT, taken when the object was in its 'reversed X-ray mode.' The observation covers over six binary orbits without interruption, enabling us to analyze the phase and intensity dependence of both the hard and the soft spectrum simultaneously. We resolve the optically thick soft X-ray spectrum, and find definite evidence for time- and phase-dependent photospheric absorption structure arising in the white dwarf atmosphere. We present a simple empirical analysis of the combined soft and hard X-ray spectra, to examine whether the effect of a better determination of the column density of neutral absorbing material, afforded by our data, would solve the problem of the large relative soft X-ray overluminosity previously observed in AM Her. We find that a single absorbing column fits the entire spectrum, and that the column densities implied are indeed substantially lower than previously estimated. However, during half the binary orbit we still determine a strong lower limit to the soft-to-hard luminosity ratio of L(sub soft)/L(sub hard) is greater than or approximately equal to 10, in conflict with the simple radiative shock models for the accretion region. We argue that this indicates the need to reexamine the luminosity problem using explicit models for the emission spectrum based on a full solution of the atmospheric radiative transfer problem.

Paerels, Frits↗
NASA NTRS2000

Field Experiments with Planetary Surface Rovers: Lessons for Mars Mission Architecture

Over the last decade, a variety of field experiments have been performed that simulate operations of a rover on Mars. These, in combination with the Pathfinder experience, lead to a realistic assessment of rover mission capabilities and to recommendations for rover technology and mission architecture to improve the science return of Mars exploration. A table summarizes field experiments that represent a range of possible mission designs and operational strategies. The experiments varied by the type and quality of imaging systems and other instrumentation, the use of orbital and aerial imaging and spectroscopy, the communcation bandwidth and command strategy, and the distance traveled. All mission simulations were blind field tests operated by science teams whose interpretations were compared to field ground truth providing an assessment of the accuracy of remote science interpretations and a better understanding of where improvements are needed.

Stoker, Carol↗
NASA NTRS2001

Evolution of the Earth and Origin of Life: The Role of Gas/Fluid Interactions with Rocks

The work under the Cooperative Agreement will be centered on questions of the evolution of Life on the early Earth and possibly on Mars. It is still hotly debated whether the essential organic molecules were delivered to the early Earth from space (by comets, meteorites or interplanetary dust particles) or were generated in situ on Earth. Prior work that has shown that the matrix of igneous minerals is a medium in which progenitors of organic molecules assemble from H2O, C02 and N2 incorporated as minority "impurities" in minerals of igneous rocks during crystallization from H2O/CO2/N2-laden magmas. The underlying processes involve a redox. conversion whereby C, H, and N become chemically reduced, while 0 becomes oxidized to the peroxy state. During Year 02 the work will be divided into three tasks. Task 1: After carboxylic (fatty) acids and N-bearing compounds have been identified, other extractable organic molecules including lipids, oily substances and amino acids will be studied. Dedicated lipid analysis will be combined with gas chromatographic-mass spectroscopic (GCMS) analysis of organic compounds extracted from minerals and rocks. Task 2: Using infrared (IR) spectroscopy, C-H entities that are indicators for the organic progenitors in mineral matrices will be studied. A preliminary heating experiment with MgO single crystals has shown that the C-H entities can be pyrolyzed, causing the IR bands to disappear, but at room temperature the IR bands reappear in a matter of days to weeks. This work will be expanded, both by studying synthetic MgO crystals and olivine crystals from the Earth's upper mantle. The C-H bands will be compared to the published "organic" IR feature of dust in the interstellar medium (ISM) and interplanetary dust particles (IDP). Task 3: A paradox marks the evolution of early Life: Oxygen is highly toxic to primitive life, yet early organisms "learned" to detoxify reactive oxygen species, to utilize oxygen, and even produce it. Why would organisms on the early anaerobic Earth be under evolutionary pressure to evolve defenses against reactive oxygen species? Minerals in igneous rocks are now known to contain peroxy. When such minerals weather, the peroxy hydrolyzes to H2O2. The hypothesis will be tested whether organisms living in intimate contact with rock surfaces are subjected to a constant trickle of H202 and thus under stress to develop strategies to either detoxify the reactive oxygen species or repair the molecular damage that they cause. Understanding these processes is central to the Astrobiology mission. It opens new avenues toward understanding the evolution of early life on Earth, and the potential for aerobic life elsewhere. This Cooperative Agreement also has a strong educational and public outreach component involving high school, undergraduate students, and high school teachers.

Freund, Friedemann↗
NASA NTRS2002

Micro-Cracking Detection in Laminated Composites

Porosity and fatigue cracking are two critical factors that affect the performance and safety of cryogenic fuel tanks and feedlines made from unlined laminated or weaved carbon/epoxy materials. This paper presents the experiments to induce fatigue cracking of laminated composites through thermal cycling as well as the feasibility of using Thermography and Ultrasound Spectroscopy technology (UT) to detect and measure such micro-cracking. Carbon/epoxy laminated composite panels were built and cut into strips. These specimens were partially submerged in liquid nitrogen while subjected to various loads on a test machine. Edges of some specimens were polished and etched to determine the degree of micro-cracking. The rest of specimens were then examined with Thermography and Ultrasound Spectroscopy NDE systems to investigate the feasibility of finding such micro-cracking in the laminated composites. Thermography is utilized to determine changes in thermal diffusivity. The degree of cracking may reduce the apparent thermal diffusivity and therefore change the thermal response on the surface. Thermography testing was conducted on a group of specimens where it is desired to have some correlation between the predetermined stress and the thermography data. Ultrasound Spectroscopy was used to determine peak changes between the pre-stressed and stressed samples. Data from the inspections were analyzed and the results are presented in this paper.

Chu, Tsuchin↗
NASA NTRS2004

Dissemination of information about the technologies of the Vision Research Lab through the World Wide Web

The Vision Research Lab at NASA John Glenn Research Center is headed by Dr. Rafat Ansari. Dr. Ansari and other researchers have developed technologies that primarily use laser and fiber optics to non-invasively detect different ailments and diseases of the eye. One of my goals as a LERCIP intern and ACCESS scholar for the 2004 summer is to inform other NASA employees, researchers and the general public about these technologies through the development of a website. The website incorporates the theme that the eye is a window to the body. Thus by investigating the processes of the eye, we can better understand and diagnosis different ailments and diseases. These ailments occur in not only earth bound humans, but astronauts as well as a result of exposure to elevated levels of radiation and microgravity conditions. Thus the technologies being developed at the Vision Research Lab are invaluable to humans on Earth in addition to those astronauts in space. One of my first goals was to research the technologies being developed at the lab. The first several days were spent immersing myself in the various articles, journals and reports about the theories behind Dynamic Light Scattering, Laser Doppler Flowmetry, Autofluoresence, Raman Spectroscopy, Polarimetry and Oximetry. Interviews with the other researchers proved invaluable to help understand these theories as well gain hands on experience with the devices being developed using these technologies. The rest of the Vision Research Team and I sat down and discussed how the overall website should be presented. Combining this information with the knowledge of the theories and applications of the hardware being developed, I worked out different ideas to present this information. I quickly learned Paint Shop Pro 8 and FrontPage 2002, as well as using online tutorials and other resources to help design an effective website. The Vision Research Lab website incorporates the anatomy and physiology of the eye, different diseases that affect the eye and the technologies being develop at the lab to help diagnosis these diseases. It also includes background information on Dr. Ansari as well as other researchers involved in the lab and it includes segments on patents, awards and achievements. There are links to help viewers navigate to internal and external websites to further investigate different ideas and hrther understand the implications of these technologies at being developed.

Dorais, Christopher M.↗
NASA NTRS2008

The Miniaturized Moessbauer Spectrometers MIMOS II on MER: Four Years of Operation - A Summary

The two Miniaturized Moessbauer Spectrometers (MIMOS II) on board the two Mars Exploration Rovers Spirit and Opportunity have now been collecting important scientific data for more than four years. The spectrometers provide information about Fe-bearing mineral phases and determine Fe oxidation states. The total amount of targets analized exceeds 600, the total integration time exceeds 260 days for both rovers. Since landing, more than five half-lives of the Co-57 MB sources have past (intensity at the time of landing approx. 150 mCi). Current integration times are about 50 hours in order to achieve reasonable statistics as opposed to 8 hours at the beginning of the mission. In total, 13 different mineral phases were detected: Olivine, pyroxene, hematite, magnetite and nanophase ferric oxide were detected at both landing sites. At Gusev, ilmenite, goethite, a ferric sulfate phase and a yet unassigned phase (in the rock Fuzzy Smith) were detected. At Meridiani, jarosite, metallic iron in meteoritic samples (kamacite), troilite, and an unassigned ferric phase were detected. Jarosite and goethite are of special interest, as these minerals are indicators for water activity. In this abstract, an overview of Moessbauer results will be given, with a focus on data obtained since the last martian winter. The MER mission has proven that Moessbauer spectroscopy is a valuable tool for the in situ exploration of extraterrestrial bodies and for the study of Febearing samples. The experience gained through the MER mission makes MIMOS II a obvious choice for future missions to Mars and other targets. Currently, MIMOS II is on the scientific payload of two approved future missions: Phobos Grunt (Russian Space Agency; 2009) and ExoMars (European Space Agency; 2013).

Fleischer, I.↗
NASA NTRS2010

Bonding and Microstructural Stability in Ni55Ti45 Studied by Experimental and Theoretical Methods

Spiral orbit tribometry friction tests performed on Ni-rich Ni55Ti45 titanium ball bearings indicate that this alloy is a promising candidate for future aerospace bearing applications. Microstructural characterization of the bearing specimens was performed using transmission electron microscopy and energy dispersive spectroscopy, with NiTi, Ni4Ti3, Ni3Ti, and Ni2Ti4Ox phases identified within the microstructure of the alloy. Density functional theory was applied to predict the electronic structure of the NixTiy phases, including the band structure and site projected density of states. Ultraviolet photoemission spectroscopy was used to verify the density of states results from the density functional theory calculations, with good agreement observed between experiment and theory.

Stott, Amanda C.↗
NASA NTRS2016

The Potassium-Argon Laser Experiment (KArLE): In Situ Geochronology for Planetary Robotic Missions

The Potassium (K) - Argon (Ar) Laser Experiment (KArLE) will make in situ noble-gas geochronology measurements aboard planetary robotic landers and roverss. Laser-Induced Breakdown Spectroscopy (LIBS) is used to measure the K abun-dance in a sample and to release its noble gases; the evolved Ar is measured by mass spectrometry (MS); and rela-tive K content is related to absolute Ar abundance by sample mass, determined by optical measurement of the ablated volume. KArLE measures a whole-rock K-Ar age to 10% or better for rocks 2 Ga or older, sufficient to resolve the absolute age of many planetary samples. The LIBS-MS approach is attractive because the analytical components have been flight proven, do not require further technical development, and provide complementary measurements as well as in situ geochronology.

KArLE↗
DOE OSTI2024

The Liquid Jet Endstation for Hard X-ray Scattering and Spectroscopy at the Linac Coherent Light Source

The ability to study chemical dynamics on ultrafast timescales has greatly advanced with the introduction of X-ray free electron lasers (XFELs) providing short pulses of intense X-rays tailored to probe atomic structure and electronic configuration. Fully exploiting the full potential of XFELs requires specialized experimental endstations along with the development of techniques and methods to successfully carry out experiments. The liquid jet endstation (LJE) at the Linac Coherent Light Source (LCLS) has been developed to study photochemistry and biochemistry in solution systems using a combination of X-ray solution scattering (XSS), X-ray absorption spectroscopy (XAS), and X-ray emission spectroscopy (XES). The pump–probe setup utilizes an optical laser to excite the sample, which is subsequently probed by a hard X-ray pulse to resolve structural and electronic dynamics at their intrinsic femtosecond timescales. The LJE ensures reliable sample delivery to the X-ray interaction point via various liquid jets, enabling rapid replenishment of thin samples with millimolar concentrations and low sample volumes at the 120 Hz repetition rate of the LCLS beam. This paper provides a detailed description of the LJE design and of the techniques it enables, with an emphasis on the diagnostics required for real-time monitoring of the liquid jet and on the spatiotemporal overlap methods used to optimize the signal. Additionally, various scientific examples are discussed, highlighting the versatility of the LJE.

EXAFS↗