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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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All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

The Concept and Role of Reference Architectures In NIF LRU Refurbishment Factories within LLNL

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) operates one of the most advanced laser systems in the world, relying on a vast number of optical components and Line Replaceable Units (LRUs) to maintain its functionality. Over time, these components degrade due to operational wear, necessitating refurbishment to sustain performance. However, many NIF LRU refurbishment factories have been “mothballed” or suffer from aging infrastructure, inconsistent work flows, and inefficiencies due to different approaches to production control and management. This paper explores the concept of reference architecture as a standardized framework to guide the redevelopment and restructuring of NIF LRU refurbishment factories. By establishing a common reference architecture, the refurbishment process can achieve reduced inefficiencies, produce quality products, and enhanced coordination across factories. This paper evaluates existing reference architectures, particularly those that integrate technical architecture, business architecture, customer context perspectives, and proposes tailored reference architecture for NIF LRU refurbishment factories.

42 ENGINEERING↗
DOE OSTI2025

Radiation damage effects in beryllium for next generation neutrino beam targetry (Final Technical Report)

Current and future high-power accelerators put severe requirements on materials used for target and beam windows and target facilities have been recognized as a critical challenge in development of future particle accelerators. In accelerators, window and target materials are exposed to extreme conditions, which include bombardment with very high energy protons (1- 100 GeV) and thermomechanical shock waves. Radiation can cause direct damage in the material, and it leads to production of transmutation products (especially helium), both phenomena having a potential adverse effect on the stability and durability of the target/window material. At high enough temperatures, He can aggregate to form gas bubbles, which in turn cause significant dimensional changes (swelling), enable easy crack propagation, and eventually cause failure by fracture. On the other hand, if the temperature is too low, radiation damage accumulates in the form of internal defects (e.g., dislocations), leading to hardening and a decreased ductility of the material. In this project, we will focus on beryllium since it is considered to be one of the candidate materials for beam windows and targets in the next-generation proton accelerators, e.g., the Long Baseline Neutrino Facility (LBNF). Radiation effects in Be have been studied in the context of nuclear fusion reactor applications. However, key differences exist between reactor and accelerator conditions, including neutron vs. proton irradiation, continuous vs. pulsed beam flux, much higher energies of bombarding particles in accelerators, and higher operating temperatures for typical reactors. For example, the impact of beam pulsing on the radiation damage and the He bubble kinetics is largely unknown. While results obtained on Be from fusion research might not be directly transferrable to understanding target materials, there is an opportunity to bring state-of-the-art tools from materials research in nuclear reactors to aid design of target and beam window materials in high-power accelerators. To this end, the overarching goal of this project are to develop an experimentally-validated computational framework capable of predicting radiation damage evolution in beryllium relevant to beam window and target conditions, focusing on He bubble formation and growth as a function of irradiation temperature. Our model will be based on the cluster dynamics formalism, where size distribution of defects and He bubbles is simulated as a function of time, temperature, and radiation dose. Parameters for the model will be taken from published experiments and from high-fidelity atomistic simulations proposed in this project. In addition, we will carry out a series of targeted ex-situ and in-situ dual-beam experiments using low-energy protons to provide critical data for validation of the model on the effects of radiation on He clustering, He bubble distribution, and dislocation loop density/size in proton irradiated Be.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Pulsed-Neutron Die-Away Response of H 2 O Targets to a D-T Generator Pulse

Pulsed-neutron die-away (PNDA) experiments were completed at Lawrence Livermore National Laboratory (LLNL). The goal of these experiments was to provide a benchmark to validate thermal neutron scattering laws of H 2 O. The experiment was conducted with a deuterium-tritium (D-T) neutron generator producing pulses of 14.1 MeV neutrons that impinged on a moderating target. The neutrons scattered and thermalized within the target and were counted as a function of time using Helium-3 ( 3 He) detectors that surrounded the target. These data provide a time-decay profile of the neutron population from which the time eigenvalue of the experiment is calculated. The time eigenvalue quantity α represents the integral parameter of interest. This report describes the measurements for H 2 O targets. The measurements were conducted over several days beginning on October 23rd, 2023. All measurements were completed at the low-scatter facility at LLNL. The evaluation identifier is FUND-LLNL-DT-H2O-PNDA-001.

3He Detectors↗
DOE OSTI2024

Quantification of carbon phases in detonation soot

Soot is a powdery substance composed of solid residues that results from the incomplete combustion of hydrocarbons. Soot holds valuable information because its chemical makeup can provide answers for condensed carbon kinetics in HE detonations by quantitively identifying what carbon species remain. For carbon-rich explosives, this is particularly important because carbon kinetics is a major pathway for energy release. Current efforts have been able to qualitatively identify the carbons and confirm their presence, but we haven’t been able to successfully quantify them. For example, small angle x-ray diffraction has been fielded to qualitatively identify carbon phases as a function of time during a detonation (work by Trevor Willey and Mike Nielson). Other work (ice experiments) has focused on measuring the “effective” static cold curve equation of state (EOS) of the recovered carbon soots.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Operational Reactor Depletion Analysis Capability

The milestone for the operational reactor depletion demonstrates a cycle depletion simulation of Watt's Bar Unit 1 Cycle 1. The simulation was performed using the VERA-CS components MPACT and COBRA-TF. The simulation was performed on the Titan and Eos machines at the Oak Ridge Leadership Computing Facility. The simulation results include the critical boron concentration, the pin resolved power, temperature, and fluid density distributions, and detector responses as a function of time. These results are presented and the critical boron concentration is compared with measured data. The comparison is reasonable given the modeling approximation used at this point. Several suggestions, both near and longer term, are given for areas of future work which include improving the methods, data, models, and computational performance. For those solution results which are not compared to measurement, e.g. power and temperature distributions, their behavior coincides with analysts' expectations. An important next step in the validation of VERA-CS will be the comparison of the computational results to the measured flux data. To satisfy this L1 milestone, numerous capabilities were successfully added as a part of supporting L2 and L3 milestones. These include: full core depletion, generation of a new cross section library, coupling of neutronics and thermal hydraulic feedback, and detector response modeling. In addition to the operational reactor depletion, several 2-D core parametric studies were performed to assess the new simulation capability and to develop guidelines on model approximations and discretizations. Some of the conclusions from these studies are: • The simulation of B-10 depletion in the coolant is necessary to accurately predict critical boron concentrations, • If the end of cycle state is of primary interest in the simulation, then significant approximations may be made in the cycle history. The ability to make use of this approximation without a notable loss in accuracy will considerably accelerate multi-cycle analysis, • The new 47-group cross section library with a transport correction of the P 0 scattering can provide solutions very efficiently and which are nearly as accurate as solutions generated with explicit P 2 scattering, and • Simplified modeling of the equilibrium xenon concentration is well predicted by the existing depletion solver, and only in certain circumstances (e.g. large and "instantaneous" changes to rod position or T/H conditions) would an explicit physical model need to be included. Overall the milestone is considered a success as the objectives were met and several new and important results were produced from this work. The results and conclusions of this milestone will continue to guide future work and become the basis for addressing the CASL Challenge Problems.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2019

Grid Impacts of Hyperloop Technology in the United States

This report provides an overview of Hyperloop technologies including the current technology developments and a brief discussion on key components of the Hyperloop system that determine the electric power requirements as a function of time. At-scale Hyperloop systems do not exist yet so a model was used to generate a set of load profiles for conceptual systems at four locations in the United States: two in California, one in Colorado, and one in Ohio. In all four cases, the modeled Hyperloop load profiles showed a pulsating characteristic in both active and reactive power. Grid modeling was performed by Pacific Northwest National Laboratory to estimate the grid impacts and to discuss grid integration challenges. This report discusses the outcomes of the grid simulations for four study cases and offers some perspective of how existing large industrial loads with similar load characteristics are treated to accommodate current grid planning guidelines. The report concludes with a discussion on how energy storage system might be used to eliminate the pulsating load characteristics or significantly reduce it.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2022

Accessing scattering amplitudes using quantum computers

Future quantum computers may serve as a tool to access non-perturbative real-time correlation functions. In this talk, we discuss the prospects of using these to study Compton scattering for arbitrary kinematics. The restriction to a finite-volume spacetime, unavoidable in foreseeable quantum-computer simulations, must be taken into account in the formalism for extracting scattering observables. One approach is to work with a non-zero iϵ-prescription in the Fourier transform to definite momentum and then to estimate an ordered double limit, in which the spacetime volume is sent to infinity before ϵ is sent to 0. For the amplitudes and parameters considered here, we find that significant volume effects arise, making the required limit very challenging. We present a practical solution to this challenge that may allow for future determinations of deeply virtual Compton scattering amplitudes, as well as many other reactions that are presently outside the scope of standard lattice QCD calculations.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2015

Fall Prevention in Community Settings: Results from Implementing Stepping On in Three States

Stepping On is a community-based intervention that has been shown in a randomized controlled trial to reduce fall risk. The Wisconsin Institute for Healthy Aging adapted Stepping On for use in the United States and developed a training infrastructure to enable dissemination. The purpose of this study is to: (1) describe the personal characteristics of Stepping On participants; (2) quantify participants’ functional and self-reported health status at enrollment, and (3) measure changes in participants’ functional and self-reported health status after completing the program. Both survey and observed functional status [timed up and go (TUG) test] data were collected between September 2011 and December 2013 for 366 participants enrolled in 32 Stepping On programs delivered in Colorado, New York, and Oregon. Paired t-tests and general estimating equations models adjusted for socio-demographic factors were performed to assess changes over the program period. Among the 266 participants with pre–post survey data, the average participant age was 78.7 (SD ± 8.0) years. Most participants were female (83.4%), white (96.9%), and in good health (49.4%). The TUG test scores decreased significantly (p < 0.001) for all 254 participants with pre–post data. The change was most noticeable among high risk participants where TUG time decreased from 17.6 to 14.4 s. The adjusted odds ratio of feeling confident about keeping from falling was more than three times greater after completing Stepping On. Further, the adjusted odds ratios of reporting “no difficulty” for getting out of a straight back chair increased by 89%. Intended for older adults who have fallen in the past or are afraid of falling, Stepping On has the potential to reduce the frequency and burden of older adult falls.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2015

Frequency and Character of Extreme Aerosol Events in the Southwestern United States: A Case Study Analysis in Arizona

This study uses more than a decade's worth of data across Arizona to characterize the spatiotemporal distribution, frequency, and source of extreme aerosol events, defined as when the concentration of a species on a particular day exceeds that of the average plus two standard deviations for that given month. Depending on which of eight sites studied, between 5% and 7% of the total days exhibited an extreme aerosol event due to either extreme levels of PM 10 , PM 2.5 , and/or fine soil. Grand Canyon exhibited the most extreme event days (120, i.e., 7% of its total days). Fine soil is the pollutant type that most frequently impacted multiple sites at once at an extreme level. PM 10 , PM 2.5 , fine soil, non-Asian dust, and Elemental Carbon extreme events occurred most frequently in August. Nearly all Asian dust extreme events occurred between March and June. Extreme Elemental Carbon events have decreased as a function of time with statistical significance, while other pollutant categories did not show any significant change. Extreme events were most frequent for the various pollutant categories on either Wednesday or Thursday, but there was no statistically significant difference in the number of events on any particular day or on weekends versus weekdays.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Synthesis and Advanced Characterization of Polymer–Protein Core–Shell Nanoparticles

Enzyme immobilization techniques are widely researched due to their wide range of applications. Polymer–protein core–shell nanoparticles (CSNPs) have emerged as a promising technique for enzyme/protein immobilization via a self-assembly process. Based on the desired application, different sizes and distribution of the polymer–protein CSNPs may be required. This work systematically studies the assembly process of poly(4-vinyl pyridine) and bovine serum albumin CSNPs. Average particle size was controlled by varying the concentrations of each reagent. Particle size and size distributions were monitored by dynamic light scattering, ultra-small-angle X-ray scattering, small-angle X-ray scattering and transmission electron microscopy. Results showed a wide range of CSNPs could be assembled ranging from an average radius as small as 52.3 nm, to particles above 1 µm by adjusting reagent concentrations. In situ X-ray scattering techniques monitored particle assembly as a function of time showing the initial particle growth followed by a decrease in particle size as they reach equilibrium. The results outline a general strategy that can be applied to other CSNP systems to better control particle size and distribution for various applications.

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

Unusual Breathing Behavior of Optically Excited Barium Titanate Nanocrystals

Coherent X-ray diffraction patterns were recorded by using an X-ray free-electron laser to illuminate barium titanate nanocrystals as a function of time delay after laser excitation. Rather than seeing any significant thermal expansion effects, the diffraction peaks were found to move perpendicular to the momentum transfer direction. This suggests a laser driven rotation of the crystal lattice, which is delayed by the aggregated state of the crystals. Internal deformations associated with crystal contacts were also observed.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2024

Nanoindentation Stress Relaxation to Quantify Dislocation Velocity–Stress Exponent

This work reports a new methodology using indentation stress relaxation to characterize the dislocation velocity–stress exponent. Through the indentation stress relaxation process, the dislocation structure builds up at the rate governed by dislocation velocity, which is a function of the externally applied stress. The relationship between the dislocation velocity and stress can thus be derived from the indentation stress relaxation data of the stress as a function of time. In this study, instrumented nanoindentation stress relaxation experiments were performed on pure aluminum samples, following three different initial displacement rates of 100, 400, and 800 nm/s. Based on the scaling properties of dislocation kinetics, the data were interpreted to derive a dislocation velocity–stress exponent of 2.5 ± 0.5 for room-temperature aluminum. Crystal plasticity finite-element simulations were performed to illustrate the sensitivity of the proposed nanoindentation stress relaxation methodology to the dislocation velocity–stress exponent value.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2017

Adsorption of Extracellular Polymeric Substances Derived from S. cerevisiae to Ceria Nanoparticles and the Effects on Their Colloidal Stability

In order to understand the adsorption preferences of extracellular polymeric substances (EPS) components derived from fungus Saccharomyces cerevisiae on sparingly soluble CeO 2 nanoparticles (CeNPs), the adsorption experiments of the EPS including organic matter with low molecular weight have been performed at pH 6.0 at room temperature (25 ± 1 °C). The subsequent effects of the coating on the dispersibility of CeNPs was systematically measured as a function of time and ionic strength ranging from 1 to 1000 mmol L –1 . Among the EPS and other components, orthophosphate and saccharides preferentially adsorb onto CeNPs, and proteins are the only major N-compounds adsorbing onto the CeNP surfaces. Adsorption of orthophosphate resulted in a dramatic decrease in ζ potential to –40 mV at pH > 5, whereas the EPS adsorption suppressed the deviation of ζ potential within a narrow range (–20–+20 mV) at pHs ranging from 3 to 11. Critical aggregation concentrations (CAC) of an electrolyte (NaCl), inorganic orthophosphate, and EPS solutions are 0.01, 0.14, and 0.25 mol L –1 , respectively, indicating that the EPS adsorption suppresses aggregation of CeNPs by the electrostatic repulsive forces derived from the adsorbed orthophosphate and the steric barrier formed by organic matter on the nanoparticle surfaces. Therefore, the EPS derived from fungus S. cerevisiae can potentially enhance colloidal dispersibility of CeNPs at circumneutral pH.

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

The Effect of Acetylation on Iron Uptake and Diffusion in Water Saturated Wood Cell Walls and Implications for Decay

Acetylation is widely used as a wood modification process that protects wood from fungal decay. The mechanisms by which acetylation protects wood are not fully understood. With these experiments, we expand upon the literature and test whether previously observed differences in iron uptake by wood were a result of decreased iron binding capacity or slower diffusion. We measured the concentration of iron in 2 mm thick wood sections at 0, 10, and 20% acetylation as a function of time after exposure to iron solutions. The iron was introduced either strongly chelated with oxalate or weakly chelated with acetate. The concentrations of iron and oxalate in solution were chosen to be similar to those found during brown rot decay, while the concentration of iron and acetate matched previous work. The iron content of oxalate-exposed wood increased only slightly and was complete within an hour, suggesting little absorption and fast diffusion, or only slight surface adsorption. The increase in iron concentration from acetate solutions with time was consistent with Fickian diffusion, with a diffusion coefficient on the order of 10 -16 m 2 s -1 . The rather slow diffusion rate was likely due to significant binding of iron within the wood cell wall. The diffusion coefficient did not depend on the acetylation level; however, the capacity for iron absorption from acetate solution was greatly reduced in the acetylated wood, likely due to the loss of OH groups. We explored several hypotheses that might explain why the diffusion rate appears to be independent of the acetylation level and found none of them convincing. Implications for brown rot decay mechanisms and future research are discussed.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Model Predictive Control of the Exit Part Temperature for an Austenitization Furnace

Quench hardening is the process of strengthening and hardening ferrous metals and alloys by heating the material to a specific temperature to form austenite (austenitization), followed by rapid cooling (quenching) in water, brine or oil to introduce a hardened phase called martensite. The material is then often tempered to increase toughness, as it may decrease from the quench hardening process. The austenitization process is highly energy-intensive and many of the industrial austenitization furnaces were built and equipped prior to the advent of advanced control strategies and thus use large, sub-optimal amounts of energy. The model computes the energy usage of the furnace and the part temperature profile as a function of time and position within the furnace under temperature feedback control. In this paper, the aforementioned model is used to simulate the furnace for a batch of forty parts under heuristic temperature set points suggested by the operators of the plant. A model predictive control (MPC) system is then developed and deployed to control the the part temperature at the furnace exit thereby preventing the parts from overheating. An energy efficiency gain of 5.3% was obtained under model predictive control compared to operation under heuristic temperature set points tracked by a regulatory control layer.

36 MATERIALS SCIENCE↗
DOE OSTI2016

CONSTRAINING THE RADIATION AND PLASMA ENVIRONMENT OF THE KEPLER CIRCUMBINARY HABITABLE-ZONE PLANETS

The discovery of many planets using the Kepler telescope includes 10 planets orbiting eight binary stars. Three binaries, Kepler-16, Kepler-47, and Kepler-453, have at least one planet in the circumbinary habitable zone (BHZ). We constrain the level of high-energy radiation and the plasma environment in the BHZ of these systems. With this aim, BHZ limits in these Kepler binaries are calculated as a function of time, and the habitability lifetimes are estimated for hypothetical terrestrial planets and/or moons within the BHZ. With the time-dependent BHZ limits established, a self-consistent model is developed describing the evolution of stellar activity and radiation properties as proxies for stellar aggression toward planetary atmospheres. Modeling binary stellar rotation evolution, including the effect of tidal interaction between stars in binaries, is key to establishing the environment around these systems. We find that Kepler-16 and its binary analogs provide a plasma environment favorable for the survival of atmospheres of putative Mars-sized planets and exomoons. Tides have modified the rotation of the stars in Kepler-47, making its radiation environment less harsh in comparison to the solar system. This is a good example of the mechanism first proposed by Mason et al. Kepler-453 has an environment similar to that of the solar system with slightly better than Earth radiation conditions at the inner edge of the BHZ. These results can be reproduced and even reparameterized as stellar evolution and binary tidal models progress, using our online tool http://bhmcalc.net.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2016

The evolution of galaxy number density at z < 8 and its implications

The evolution of the number density of galaxies in the universe, and thus also the total number of galaxies, is a fundamental question with implications for a host of astrophysical problems including galaxy evolution and cosmology. However, there has never been a detailed study of this important measurement, nor a clear path to answer it. To address this we use observed galaxy stellar mass functions up to z ∼ 8 to determine how the number densities of galaxies change as a function of time and mass limit. We show that the increase in the total number density of galaxies (ϕ {sub T}), more massive than M {sub *} = 10{sup 6} M {sub ⊙}, decreases as ϕ {sub T} ∼ t {sup −1}, where t is the age of the universe. We further show that this evolution turns over and rather increases with time at higher mass lower limits of M {sub *} > 10{sup 7} M {sub ⊙}. By using the M {sub *} = 10{sup 6} M {sub ⊙} lower limit we further show that the total number of galaxies in the universe up to z = 8 is 2.0{sub −0.6}{sup +0.7}×10{sup 12} (2 trillion), almost a factor of 10 higher than would be seen in an all sky survey at Hubble Ultra-Deep Field depth. We discuss the implications for these results for galaxy evolution, as well as compare our results with the latest models of galaxy formation. These results also reveal that the cosmic background light in the optical and near-infrared likely arise from these unobserved faint galaxies. We also show how these results solve the question of why the sky at night is dark, otherwise known as Olbers’ paradox.

79 ASTRONOMY AND ASTROPHYSICS↗

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