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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Conceptual design of front ends for the advanced photon source multi-bend achromats upgrade

The proposed Advanced Photon Source (APS) upgrade from a double-bend achromats (DBA) to multi-bend achromats (MBA) lattice with ring energy change from 7 GeV to 6 GeV and beam current from 100 mA to 200 mA poses new challenges for front ends. All front ends must be upgraded to fulfill the following requirements: 1) handle the high heat load from two insertion devices in either inline or canted configuration, 2) include a clearing magnet in the front end to deflect and dump any electrons in case the electrons escape from the storage ring during swap-out injection with the safety shutters open, 3) incorporate the next generation x-ray beam position monitors (XBPMs) into the front end to meet the new stringent beam stability requirements. This paper presents the evaluation of the existing APS front ends and standardizes the insertion device (ID) front ends into two types: one for the single beam and one for the canted beams. The conceptual design of high heat load front end (HHLFE) and canted undulator front end (CUFE) for APS MBA upgrade is presented.

43 PARTICLE ACCELERATORS↗
DOE OSTI2016

X-ray optics testing beamline 1-BM at the advanced photon source

Beamline 1-BM at the APS has been reconfigured in part for testing of synchrotron optics with both monochromatic and white beams. Operational since 2013, it was reconfigured to accommodate users of the APS as well as users from other DOE facilities. Energies between 6 and 28 keV are available. The beamline was reconfigured to remove two large mirrors and to provide a 100 mm wide monochromatic beam at 54 m from the source. In addition a custom white beam shutter was implemented for topography exposures as short as 65 millisec over the full available horizontal width. Primary agendas include both white beam and monochromatic beam topography, Talbot grating interferometry, and tests of focusing optics. K-B mirrors, MLLs, and FZPs have been characterized. Measurements of the spatial coherence lengths on the beamline were obtained with Talbot interferometry. Topography data has been reported.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

Sequential x-ray diffraction topography at 1-BM x-ray optics testing beamline at the advanced photon source

We report progress on implementation and commissioning of sequential X-ray diffraction topography at 1-BM Optics Testing Beamline of the Advanced Photon Source to accommodate growing needs of strain characterization in diffractive crystal optics and other semiconductor single crystals. The setup enables evaluation of strain in single crystals in the nearly-nondispersive double-crystal geometry. Si asymmetric collimator crystals of different crystallographic orientations were designed, fabricated and characterized using in-house capabilities. Imaging the exit beam using digital area detectors permits rapid sequential acquisition of X-ray topographs at different angular positions on the rocking curve of a crystal under investigation. Results on sensitivity and spatial resolution are reported based on experiments with high-quality Si and diamond crystals. The new setup complements laboratory-based X-ray topography capabilities of the Optics group at the Advanced Photon Source.

43 PARTICLE ACCELERATORS↗
DOE OSTI2016

Conceptual moderator studies for the Spallation Neutron Source short-pulse second target station

Candidate moderator configurations for a short-pulse second target station (STS) at the Oak Ridge National Laboratory Spallation Neutron Source (SNS) have been identified using a global optimizer framework built around the MCNPX particle transport code. Neutron brightness metrics were selected as the figure-of-merit. We assumed that STS would use one out of six proton pulses produced by an SNS accelerator upgraded to operate at 1.3 GeV proton energy, 2.8 MW power and 60 Hz repetition rate. The simulations indicate that the peak brightness can be increased by a factor of 5 and 2.5 on a per proton pulse basis compared to the SNS first target station for both coupled and decoupled para-hydrogen moderators, respectively. Additional increases by factors of 3 and 2 were demonstrated for coupled and decoupled moderators, respectively, by reducing the area of neutron emission from 100 × 100 mm{sup 2} to 20 × 20 mm{sup 2}. This increase in brightness has the potential to translate to an increase of beam intensity at the instruments’ sample positions even though the total neutron emission of the smaller moderator is less than that of the larger. This is especially true for instruments with small samples (beam dimensions). The increased fluxes in the STS moderators come at accelerated poison and de-coupler burnout and higher radiation-induced material damage rates per unit power, which overall translate into lower moderator lifetimes. A first effort was undertaken to group decoupled moderators into a cluster collectively positioning them at the peak neutron production zone in the target and having a three-port neutron emission scheme that complements that of a cylindrical coupled moderator.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

A liquid jet setup for x-ray scattering experiments on complex liquids at free-electron laser sources

In this paper we describe a setup for x-ray scattering experiments on complex fluids using a liquid jet. The setup supports Small and Wide Angle X-ray Scattering (SAXS/WAXS) geometries. The jet is formed by a gas-dynamic virtual nozzle (GDVN) allowing for diameters ranging between 1 μm and 20 μm at a jet length of several hundred μm. To control jet properties such as jet length, diameter, or flow rate, the instrument is equipped with several diagnostic tools. Three microscopes are installed to quantify jet dimensions and stability in situ. The setup has been used at several beamlines performing both SAXS and WAXS experiments. As a typical example we show an experiment on a colloidal dispersion in a liquid jet at the X-ray Correlation Spectroscopy instrument at the Linac Coherent Light Source free-electron laser.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

A new H{sub 2}{sup +} source: Conceptual study and experimental test of an upgraded version of the VIS—Versatile ion source

The versatile ion source is an off-resonance microwave discharge ion source which produces a slightly overdense plasma at 2.45 GHz of pumping wave frequency extracting more than 60 mA proton beams and 50 mA He{sup +} beams. DAEδALUS and IsoDAR experiments require high intensities for H{sub 2}{sup +} beams to be accelerated by high power cyclotrons for neutrinos generation. In order to fulfill the new requirements, a new plasma chamber and injection system has been designed and manufactured for increasing the H{sub 2}{sup +} beam intensity. In this paper the studies for the increasing of the H{sub 2}{sup +}/p ratio and for the design of the new plasma chamber and injection system will be shown and discussed together with the experimental tests carried out at Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali del Sud (INFN-LNS) and at Best Cyclotron Systems test-bench in Vancouver, Canada.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2020

Design of target irradiation and diagnostic chamber to study ps-laser generated plasma as a source of singly charged ions for external injection into an electron beam ion source

High repetition-rate (~10 kHz) ps-lasers are becoming available on the market with reasonable cost and may offer several advantages compared to ns-lasers by generating nearly continuous beams of singly charged ions appropriate for the “slow” injection mode into the Electron Beam Ion Source (EBIS). To evaluate these advantages, we will perform studies of a ps-laser generated plasma using a laser with a pulse duration of 8 ps and energy up to 5 mJ per pulse. A vacuum chamber equipped with a 3D target positioner, a focusing lens, and a Faraday Cup has been designed and built for this study. Lens-to-target distance variations have been measured using a laser tracker over the whole range of horizontal and vertical translation for all five targets we will use. The variations were found to be within ±150 µm. This level of “target flatness” should be acceptable for our experimental conditions. Ion currents and ion pulse durations of various elements (from Al to Ta) will be measured for different target irradiation conditions (focal spot size and laser pulse energy). The results obtained will allow us to specify all parameters and geometry of a laser ion source based on a ps-laser to provide external ion injection into the relativistic heavy ion collider EBIS

43 PARTICLE ACCELERATORS↗
DOE OSTI2025

Open-source simulation program for extreme ultraviolet and soft x-ray sources based on high-harmonic generation

Light sources based on high-harmonic generation (HHG) underpin ultrafast spectroscopy experiments across a large range of photon energies, spanning from the extreme ultraviolet to the soft x-ray. To this day, their design, implementation, and improvement presens unique challenges, but can be aided by numerical tools. Here we present a new simulation program designed for this purpose, which takes both macroscopic and microscopic aspects of high-harmonic generation into account and is therefore applicable across the broad range of parameters which HHG based light sources are today utilized. The program is validated by comparison with published experimental results and by calculating harmonic emission in four common experimental configurations.

Femtosecond lasers↗
DOE OSTI2018

An assessment of potential CO2 Sources throughout the Illinois Basin Subtask 5.1 – CO2 Source Assessment Topical Report

Large-scale anthropogenic CO2 sources (>100,000 tonnes/year) were catalogued and assessed for the Illinois East Sub-Basin project area. The portfolio of sources is quite diverse, and contains not only fossil-based power generation facilities but also ethanol, chemical, and refinery facilities. Over 60% of the facilities are relatively new (i.e. post year 2000 construction) hence increasing the likelihood that retrofitting the facility with a carbon capture plant is feasible. Two of the facilities have indicated interest in being “early adopters” should the CarbonSAFE project eventually transition to a build and operate phase: the Prairie State Generating Company’s electricity generation facility near Marissa, Illinois, and Quasar Syngas, LLC’s Wabash ammonia/direct-reduced iron plant, currently in development north of Terre Haute, Indiana.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2016

PB-AM: An open-source, fully analytical linear poisson-boltzmann solver

Here, we present the open source distributed software package Poisson-Boltzmann Analytical Method (PB-AM), a fully analytical solution to the linearized PB equation, for molecules represented as non-overlapping spherical cavities. The PB-AM software package includes the generation of outputs files appropriate for visualization using visual molecular dynamics, a Brownian dynamics scheme that uses periodic boundary conditions to simulate dynamics, the ability to specify docking criteria, and offers two different kinetics schemes to evaluate biomolecular association rate constants. Given that PB-AM defines mutual polarization completely and accurately, it can be refactored as a many-body expansion to explore 2- and 3-body polarization. Additionally, the software has been integrated into the Adaptive Poisson-Boltzmann Solver (APBS) software package to make it more accessible to a larger group of scientists, educators, and students that are more familiar with the APBS framework.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2016

Sources of errors in the simulation of south Asian summer monsoon in the CMIP5 GCMs

Accurate simulation of the South Asian summer monsoon (SAM) is still an unresolved challenge. There has not been a benchmark effort to decipher the origin of undesired yet virtually invariable unsuccessfulness of general circulation models (GCMs) over this region. This study analyzes a large ensemble of CMIP5 GCMs to show that most of the simulation errors in the precipitation distribution and their driving mechanisms are systematic and of similar nature across the GCMs, with biases in meridional differential heating playing a critical role in determining the timing of monsoon onset over land, the magnitude of seasonal precipitation distribution and the trajectories of monsoon depressions. Errors in the pre-monsoon heat low over the lower latitudes and atmospheric latent heating over the slopes of Himalayas and Karakoram Range induce significant errors in the atmospheric circulations and meridional differential heating. Lack of timely precipitation further exacerbates such errors by limiting local moisture recycling and latent heating aloft from convection. Most of the summer monsoon errors and their sources are reproducible in the land–atmosphere configuration of a GCM when it is configured at horizontal grid spacing comparable to the CMIP5 GCMs. While an increase in resolution overcomes many modeling challenges, coarse resolution is not necessarily the primary driver in the exhibition of errors over South Asia. These results highlight the importance of previously less well known pre-monsoon mechanisms that critically influence the strength of SAM in the GCMs and highlight the importance of land–atmosphere interactions in the development and maintenance of SAM.

CMIP5↗
DOE OSTI2020

Engineering the cellulolytic extreme thermophile Caldicellulosiruptor bescii to reduce carboxylic acids to alcohols using plant biomass as the energy source

Abstract Caldicellulosiruptor bescii is the most thermophilic cellulolytic organism yet identified (Topt 78 °C). It grows on untreated plant biomass and has an established genetic system thereby making it a promising microbial platform for lignocellulose conversion to bio-products. Here, we investigated the ability of engineered C. bescii to generate alcohols from carboxylic acids. Expression of aldehyde ferredoxin oxidoreductase (aor from Pyrococcus furiosus) and alcohol dehydrogenase (adhA from Thermoanaerobacter sp. X514) enabled C. bescii to generate ethanol from crystalline cellulose and from biomass by reducing the acetate produced by fermentation. Deletion of lactate dehydrogenase in a strain expressing the AOR–Adh pathway increased ethanol production. Engineered strains also converted exogenously supplied organic acids (isobutyrate and n-caproate) to the corresponding alcohol (isobutanol and hexanol) using both crystalline cellulose and switchgrass as sources of reductant for alcohol production. This is the first instance of an acid to alcohol conversion pathway in a cellulolytic microbe.

Biotechnology & Applied Microbiology↗
DOE OSTI2019

Utility of Atmospheric Transport Runs Done Backwards in Time for Source Term Estimation

In a general sense, the equations describing transport of an atmospheric contaminant are reversible in time. However, the time reversibility is not perfect. For a source term estimation problem, one atmospheric transport model (ATM) run done backwards in time to represent the influence of a single sample value can yield as much information as hundreds or thousands of forwards ATM runs. Thus, backwards ATM are often used to limit the computational burden of an analysis. A large number of paired ATM runs at 14 release locations were used to explore the agreement between dilution factors for the forward and backwards time directions. Four of the release locations have correlation coefficients between forward and backwards dilution factors greater than 0.9. None of the four have large elevation changes within 100 km of the release location. The two release locations with the lowest correlation coefficients are in mountainous terrain with large elevation differences. Elevation changes have a greater negative influence on the correlations than distance to the sampler or plume transit times. The locations of the releases were estimated using dilution factors from backwards ATM runs. Many of the location estimates are close to the release point, vindicating the general approach of using ATM runs backwards in time. Aggregated over the 14 release points, 26% of the location estimates were within 10 km of the release point, 61% were within 25 km, 80% were within 50 km, and 87% were within 75 km. Most of the remaining 13% (poor matches) occur for two release locations in mountainous terrain. Good time-reversibility cannot be guaranteed for a new analysis, so we recommend that any source term solution using backwards ATM runs should include comparisons based on forward ATM runs. As an example, calculations show good agreement between dilutions in different time-directions for samples taken after the announced nuclear test by the Democratic People’s Republic of Korea in 2013.

Eslinger, Paul W.↗
DOE OSTI2018

Liberation and release of rare earth minerals from Middle Kittanning, Fire Clay, and West Kentucky No. 13 coal sources

Here, a laboratory REE release test procedure was designed to better understand the association and liberation characteristics of rare earth elements (REEs) from coal-based material, such as coal middlings and refuse. For this particular study, three samples of mixed-phase, middling material was collected from three coal preparation plants operating in three different coal basins and coal seams, namely Fire Clay, Middle Kittanning, and West Kentucky #13. In these release tests, the mixed-phase material was first ground in a laboratory ball mill for a designated amount of time and subsequently decarbonized using staged flotation. The REE content of the high ash tailings and low ash concentrate was determined, and the process was repeated for various target grind sizes down to the micron range. The results indicate that smaller grind sizes produce increased REE concentrations in the high ash tailings, and this result is predominantly driven by the increased ash content in the decarbonized tailings. The grinding characteristics of the Fire Clay coal source showed that more energy is needed to achieve the desired particle size reduction; however further size reduction of this sample resulted in a significantly higher ash and REE content in the tailings material due to improved liberation. For the Middle Kittanning and West Kentucky #13 sources, the grinding and release data indicates that the mineral matter is liberated at a coarser particle size, and micronizing the coals only produces marginal improvements in rare earth mineral liberation and recovery.

01 COAL, LIGNITE, AND PEAT↗