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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 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

The dilation aided single–line–of–sight x–ray camera for the National Ignition Facility: Characterization and fielding

Crystal x–ray imaging is commonly used in inertial confinement fusion and laser-plasma interaction applications as it has advantages compared to pinhole imaging, such as higher signal throughput, better achievable spatial resolution, and chromatic selection. Yet, currently used x–ray detectors are only able to obtain a single time resolved image per crystal. The dilation aided single–line–of–sight x–ray camera described here was designed for the National Ignition Facility (NIF) and combines two recent diagnostic developments, the pulse dilation principle used in the dilation x-ray imager and a ns–scale multi-frame camera that uses a hold and readout circuit for each pixel. This enables multiple images to be taken from a single–line–of–sight with high spatial and temporal resolution. Presently, the instrument can record two single–line–of–sight images with spatial and temporal resolution of 35 μm and down to 35 ps, respectively, with a planned upgrade doubling the number of images to four. Here we present the dilation aided single–line–of–sight camera for the NIF, including the x–ray characterization measurements obtained at the COMET laser, as well as the results from the initial timing shot on the NIF.

47 OTHER INSTRUMENTATION↗
DOE OSTI2018

Bremsstrahlung x-ray generation for high optical depth radiography applications on the National Ignition Facility [Bremsstrahlung x-ray generation for opacity radiography applications on the National Ignition Facility]

Here, we have tested a set of x-ray sources for use as probes of highly attenuating, laser-driven experiments on the National Ignition Facility (NIF). Unlike traditional x-ray sources that optimize for a characteristic atomic transition (often the n = 2 → n = 1 transition in ionized, He-like atoms), the design presented here maximizes the total photon flux by optimizing for intense, broadband Bremsstrahlung radiation. Three experiments were performed with identical targets, including a uranium x-ray source foil and a tungsten substrate with a narrow (25 μm wide) collimating slit to produce a quasi-1D x-ray source. Two experiments were performed using 12 beams from the NIF laser, each delivering approximately 46 kJ of laser energy but with different laser spatial profiles. This pair yielded similar temporal x-ray emission profiles, spatial resolution, and inferred hot electron temperature. A third experiment with only 6 beams delivering approximately 25 kJ produced a lower hot electron temperature and significantly lower x-ray flux, as well as poorer spatial resolution. The data suggest that laser pointing jitter may have affected the location and intensity of the emitting plasma, producing an emission volume that was not well centered behind the collimating slit and lower intensity than designed. However, the 12-beam design permits x-ray radiography through highly attenuating samples, where lower energy line-emission x-ray sources would be nearly completely attenuated.

47 OTHER INSTRUMENTATION↗
DOE OSTI2022

Characterization of the hardened single line of sight camera at the National Ignition Facility

The hardened single line of sight camera has been recently characterized in preparation for its deployment on the National Ignition Facility. The latest creation based on the pulse-dilation technology leads to many new features and improvements over the previous-generation cameras to provide better quality measurements of inertial confinement fusion experiments, including during high neutron yield implosions. Here, we present the characterization data that illustrate the main performance features of this instrument, such as extended dynamic range and adjustable internal magnification, leading to improved spatial resolution.

Trosseille, C. (ORCID:0000000289430482)↗
DOE OSTI2014

Novel Characterization of Capsule X-Ray Drive at the National Ignition Facility [Using ViewFactor Experiments to Measure Hohlraum X-Radiation Drive from the Capsule Point-of-View in Ignition Experiments on the National Ignition Facility]

Here, indirect drive experiments at the National Ignition Facility are designed to achieve fusion by imploding a fuel capsule with x rays from a laser-driven hohlraum. Previous experiments have been unable to determine whether a deficit in measured ablator implosion velocity relative to simulations is due to inadequate models of the hohlraum or ablator physics. ViewFactor experiments allow for the first time a direct measure of the x-ray drive from the capsule point of view. The experiments show a 15%–25% deficit relative to simulations and thus explain nearly all of the disagreement with the velocity data. In addition, the data from this open geometry provide much greater constraints on a predictive model of laser-driven hohlraum performance than the nominal ignition target.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2017

Transition from Collisional to Collisionless Regimes in Interpenetrating Plasma Flows on the National Ignition Facility

A study of the transition from collisional to collisionless plasma flows has been carried out at the National Ignition Facility using high Mach number (M > 4) counterstreaming plasmas. In these experiments, CD-CD and CD-CH planar foils separated by 6–10 mm are irradiated with laser energies of 250 kJ per foil, generating ~1000 km/s plasma flows. Varying the foil separation distance scales the ion density and average bulk velocity and, therefore, the ion-ion Coulomb mean free path, at the interaction region at the midplane. The characteristics of the flow interaction have been inferred from the neutrons and protons generated by deuteron-deuteron interactions and by x-ray emission from the hot, interpenetrating, and interacting plasmas. A localized burst of neutrons and bright x-ray emission near the midpoint of the counterstreaming flows was observed, suggesting strong heating and the initial stages of shock formation. As the separation of the CD-CH foils increases we observe enhanced neutron production compared to particle-in-cell simulations that include Coulomb collisions, but do not include collective collisionless plasma instabilities. Here, the observed plasma heating and enhanced neutron production is consistent with the initial stages of collisionless shock formation, mediated by the Weibel filamentation instability.

42 ENGINEERING↗
DOE OSTI2017

Refurbishment of a used in-vacuum undulator from the National Synchrotron Light Source for the National Synchrotron Light Source-II ring

The National Synchrotron Light Source (NSLS) ceased operation in September 2014 and was succeeded by NSLS-II. There were four in-vacuum undulators (IVUs) in operation at NSLS. The most recently constructed IVU for NSLS was the mini-gap undulator (MGU-X25, to be renamed IVU18 for NSLS-II), which was constructed in 2006. This device was selected to be reused for the New York Structural Biology Consortium Microdiffraction beamline at NSLS-II. At the time of construction, IVU18 was a state-of-the-art undulator designed to be operated as a cryogenic permanent-magnet undulator. Due to the more stringent field quality and impedance requirements of the NSLS-II ring, the transition region was redesigned. The control system was also updated to NSLS-II specifications. As a result, this paper reports the details of the IVU18 refurbishment activities including additional magnetic measurement and tuning.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Swedish Government Representatives Visit Nevada National Security Site and Los Alamos National Laboratory for Nuclear Nonproliferation Workshop

In October 2013, Los Alamos National Laboratory, with sponsorship and support from the NNSA Office of Nonproliferation and International Security, Office of Nuclear Controls (NA-242), hosted representatives from various agencies of the Swedish Government for a Nuclear Nonproliferation Workshop (NNPW). The purpose of the visit was to further promote the strong and mutually beneficial working relationship between the U.S. and Sweden on nuclear nonproliferation and related nuclear export control and safeguards subjects. Sweden is an important “like-minded” partner in the NSG and in other multilateral activities, such as implementation of special nuclear trade sanctions against Iran and North Korea, which work to combat the global nuclear proliferation problem. Sweden has been especially active in policy and technical initiatives in the NSG that serve to make the NSG’s export control lists better and more effective in combating nuclear proliferation activities.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2014

AVTA federal fleet PEV readiness data logging and characterization study for the National Park Service: Grand Canyon National Park

This report focuses on the Grand Canyon National Park (GCNP) fleet to identify daily operational characteristics of select vehicles and report findings on vehicle and mission characterizations to support the successful introduction of PEVs into the agencies’ fleets. Individual observations of these selected vehicles provide the basis for recommendations related to electric vehicle adoption and whether a battery electric vehicle or plug-in hybrid electric vehicle (collectively PEVs) can fulfill the mission requirements.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2014

AVTA Federal Fleet PEV Readiness Data Logging and Characterization Study for the National Park Service: Sleeping Bear Dunes National Lakeshore

This report focuses on the Sleeping Bear Dunes National Lakeshore (SLBE) fleet to identify daily operational characteristics of select vehicles and report findings on vehicle and mission characterizations to support the successful introduction of plug-in electric vehicles (PEVs) into the agencies’ fleets. Individual observations of these selected vehicles provide the basis for recommendations related to electric vehicle adoption and whether a battery electric vehicle (BEV) or plug-in hybrid electric vehicle (PHEV) (collectively plug-in electric vehicles, or PEVs) can fulfill the mission requirements.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2015

The National Ignition Facility (NIF) Diagnostic Set at the Completion of the National Ignition Campaign (NIC) September 2013

At the completion of the National Ignition Campaign NIF had about 36 different types of diagnostics. These were based on several decades of development on Nova and OMEGA and involved the whole US ICF community. A plan for a limited of NIF Diagnostics was documented by the Joint Central Diagnostic Team in the NIF Conceptual Design Report in 1994. These diagnostics and many more were installed diagnostics by two decades later. We give a short description of each of the 36 different types of NIC diagnostics grouped by the function of the diagnostics, namely target drive, target response and target assembly, stagnation and burn. A comparison of NIF diagnostics with the Nova diagnostics shows that the NIF diagnostic capability is broadly equivalent to that of Nova’s in 1999. NIF diagnostics have a much greater degree of automation and rigor than Nova’s and the NIF diagnostic suite incorporates some scientific innovation compared to Nova and OMEGA namely one much higher speed x-ray imager. Directions for future NIF diagnostics are discussed.

42 ENGINEERING↗
DOE OSTI2018

Abstract - Cooperative Research and Development Agreement between Ames National Laboratory and National Energy Technology Laboratory AGMT-0609

The goal of this project is to develop a merged environment for simulation and analysis (MESA) at the National Energy Technology Laboratory’s (NETL) Hybrid Performance (Hyper) project laboratory. The MESA sensor lab developed as a component of this research will provide a development platform for investigating: 1) advanced control strategies, 2) testing and development of sensor hardware, 3) various modeling in-the-loop algorithms and 4) other advanced computational algorithms for improved plant performance using sensors, real-time models, and complex systems tools.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2018

The National Academies of Sciences, Engineering, Medicine: Research Associateship Program with NETL - National Energy Technology Laboratory and NETL/MHEP - Methane Hydrates Fellowship Program

During the reporting period, the National Academies of Sciences, Engineering, and Medicine (the Academies) NRC conducted the following activities in support of the subject contract: outreach and promotion; processing and review of applications; administration of awards; and, outcomes reporting.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Los Alamos National Laboratory 2018 Monitoring Season for storm water and atmospheric deposition samples from Bandelier National Monument under Permit # BAND-2018-SCI-0006 - 2018 Monitoring Season Summary

Los Alamos National Laboratory (LANL) completed the 2018 monitoring season for a multi-year monitoring project to characterize background/baseline conditions around and distal to the Pajarito Plateau, Northern New Mexico. The following media were included in the 2018 monitoring season: precipitation, storm water, and atmospheric deposition. Data generated in this study will be used to characterize and quantify the impacts to water quality from natural background sediments and atmospheric deposition of persistent organic pollutants such as polychlorinated biphenyls [PCBs]. Details specific to 2018 monitoring season are presented below.

54 ENVIRONMENTAL SCIENCES↗