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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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Temperature of the fcc-bcc (face-centered cubic – body-centered cubic) solid-solid phase transition in Fe calculated as Teq = Tinst ΔEfcc-bcc/ΔEbcc-m. (where m. stands for martensitic mixture that bcc-Fe converts into at Tinst) maps out a curve which is consistent with the line of the fast recrystallization threshold observed in the recent experiments on Fe at ESRF.
Investigation of pyrocumulus column collapse. Effects of fuel heterogeneities on fire spread. Role of vorticity in fire rate of spread.
Fusion yield reduction (hot spot) & recovery (cold fuel). Taming mix at gas-ice interface via a combination of magnetic, hot-spot viscous, & ablative stabilization.
• 25 shots on Omega measured the effect of initial surface roughness on the evolution of mixing due to shear flow. • First experiments on Omega EP of the oblique shock experiment returned high-quality radiographs showing instability growth. • Completed design of first beryllium-capsule laser pulse for NIF that will assess risk of SBS backscatter.
Abstract not provided
The Institute for Nuclear Theory program, Heavy Flavor and Electro- magnetic Probes in Heavy-Ion Collisions (INT 14-3), was held 15 September to 10 October 2014. In addition to the four organizers: Ramona Vogt (LLNL and UC Davis), Peter Petreczky (BNL), Anthony Frawley (Florida State), and Enrico Scomparin (INFN Torino), the program was attended by 34 other participants spread out over the four week period. Almost all participants were recognized experts in the field and were invited to take part. Eight of the participants were postdocs and five were women. There are two main thrusts to the study of heavy quarks and quarkonia in heavy-ion physics: “hot matter” (effects specific to the high temperature medium produced in heavy-ion or nucleus-nucleus collisions) and “cold nu- clear matter” (effects that are present already in proton-nucleus collisions and are a baseline against which hot matter effects must be compared) as well as production of the heavy quarks and quarkonium (bound states of heavy quark-antiquark pairs) in perturbative QCD. The program was structured so that the first two weeks were generally devoted to hot matter, especially lattice QCD. The second half was devoted to issues related to production and cold matter effects. An intense 2.5 day workshop, from 29 September to 1 October. Although a theory program, experimentalists attended throughout, giving talks on recent data and future facilities.
Phonon spectra at two different densities of bcc-Be at T slightly below the corresponding Tm. At P=0 the system is dynamically unstable at low T but stabilizes at T close to Tm=1560 K. However, unless the system size is 1458 atoms or higher (the number of valence electrons is ~ 3000 or more) dynamic instability is still present, in the form of an imaginary phonon branch at the Γ- point (Fig. 1). At P=300 GPa the system is dynamically stable for as low as 128 atoms (Fig. 2). This example demonstrates that at present it is unfeasible to treat bcc-Fe in the region of its dynamic instability (megabar pressure range) with the existing first-principles software (e.g., VASP) which only allows treating bcc-Fe with up to ~ 500 atoms (~7000 valence electrons).
Abstract not provided.
Key challenges for the Advanced Fuels Campaign are the development of fuel technologies to enable major increases in fuel performance (safety, reliability, power and burnup) beyond current technologies, and development of characterization methods and predictive fuel performance models to enable more efficient development and licensing of advanced fuels. Ceramic fuel development activities for fiscal year 2015 fell within the areas of 1) National and International Technical Integration, 2) Advanced Accident Tolerant Ceramic Fuel Development, 3) Advanced Techniques and Reference Materials Development, and 4) Fabrication of Enriched Ceramic Fuels. High uranium density fuels were the focus of the ceramic fuels efforts. Accomplishments for FY15 primarily reflect the prioritization of identification and assessment of new ceramic fuels for light water reactors which have enhanced accident tolerance while also maintaining or improving normal operation performance, and exploration of advanced post irradiation examination techniques which will support more efficient testing and qualification of new fuel systems.
Swift/T is a key success from the ExM: System support for extreme-scale, many-task applications1 X-Stack project, which proposed to use concurrent dataflow as an innovative programming model to exploit extreme parallelism in exascale computers. The Swift/T component of the project reimplemented the Swift language from scratch to allow applications that compose scientific modules together to be build and run on available petascale computers (Blue Gene, Cray). Swift/T does this via a new compiler and runtime that generates and executes the application as an MPI program. We assume that mission-critical emerging exascale applications will be composed as scalable applications using existing software components, connected by data dependencies. Developers wrap native code fragments using a higherlevel language, then build composite applications to form a computational experiment. This exemplifies hierarchical concurrency: lower-level messaging libraries are used for fine-grained parallelism; highlevel control is used for inter-task coordination. These patterns are best expressed with dataflow, but static DAGs (i.e., other workflow languages) limit the applications that can be built; they do not provide the expressiveness of Swift, such as conditional execution, iteration, and recursive functions.
CEMAC has conducted four major studies on the manufacturing of clean energy technologies. Three of these focused on the end product: solar photovoltaic modules, wind turbines, and automotive lithium-ion batteries. The fourth area focused on a key material for manufacturing clean energy technologies, carbon fiber.
LLNL executed two HED Fused Silica Dome experiments as part of the complex hydrodynamics campaign on NIF. These shots assessed breakout times and velocities of shocks at five different angles separated by 45°. Each target looked at three different locations on the capsule measuring the shock breakout time and speed. The experiments used a significantly larger hohlraum and energy in the laser pulse than in previous complex hydrodynamics hohlraums. LLNL conducted a shot on NIF to continue developing a high pressure drive platform for Rayleigh-Taylor strength experiments. VISAR was the primary diagnostic and returned good quality data.
To meet the nation’s critical challenges, the Department of Energy (DOE) national laboratories have always pushed the boundaries of science, technology, and engineering. The Atomic Energy Act of 1954 provided the basis for these laboratories to engage in the cutting edge of science and technology and respond to technological surprises, while retaining the best scientific and technological minds. To help re-energize this commitment, in 1991 the U.S. Congress authorized the national laboratories to devote a relatively small percentage of their budget to creative and innovative work that serves to maintain their vitality in disciplines relevant to DOE missions. Since then, this effort has been formally called the Laboratory Directed Research and Development (LDRD) Program. LDRD has been an essential mechanism to enable the laboratories to address DOE’s current and future missions with leading-edge research proposed independently by laboratory technical staff, evaluated through expert peer-review committees, and funded by the individual laboratories consistent with the authorizing legislation and the DOE LDRD Order 413.2C.
Data are plotted for densities from 2 to 6 g/cc.
Key challenges for the Advanced Fuels Campaign are the development of fuel technologies to enable major increases in fuel performance (safety, reliability, power and burnup) beyond current technologies, and development of characterization methods and predictive fuel performance models to enable more efficient development and licensing of advanced fuels. Ceramic fuel development activities for fiscal year 2016 fell within the areas of 1) National and International Technical Integration, 2) Advanced Accident Tolerant Ceramic Fuel Development, 3) Advanced Techniques and Reference Materials Development, and 4) Fabrication of Enriched Ceramic Fuels. High uranium density fuels were the focus of the ceramic fuels efforts. Accomplishments for FY16 primarily reflect the prioritization of identification and assessment of new ceramic fuels for light water reactors which have enhanced accident tolerance while also maintaining or improving normal operation performance, and exploration of advanced post irradiation examination techniques which will support more efficient testing and qualification of new fuel systems.
The fiscal year started with the Rotary Valve (RV) being reassembled after having crashed in June of 2015. The crash occurred when the RV inner surface contacted the housing. The cause of the crash was never confirmed. No particles were found in the 2.5 thousandths of an inch gap and the filters the helium gas passed through were all clean. There were marks on the bearings that looked like electrostatic discharge as shown below in Figure 1. These marks hadn’t been seen before and there were similar discharge marks on some of the ball bearings. Examples of this were found in a literature search of bearing failures. This leads to a possible cause due to this arcing affecting the rotational accuracy of the bearings driving the RV into the housing.
The Argonne Leadership Computing Facility provides supercomputing capabilities to the scientific and engineering community to advance fundamental discovery and understanding in a broad range of disciplines.