3D HYDRA simulations of NIF targets (open access)

3D HYDRA simulations of NIF targets

The performance of NIF target designs is simulated in three dimensions using the HYDRA multiphysics radiation hydrodynamics code. In simulations of a cylindrical NIF hohlraum that include an imploding capsule, all relevant hohlraum features and the detailed laser illumination pattern, the motion of the wall material inside the hohlraum shows a high degree of axisymmetry. Laser light is able to propagate through the entrance hole for the required duration of the pulse. Gross hohlraum energetics mirror the results from an axisymmetric simulation. A NIF capsule simulation resolved the full spectrum of the most dangerous modes that grow from surface roughness. Hydrodynamic instabilities evolve into the weakly nonlinear regime. There is no evidence of anomalous low mode growth driven by nonlinear mode coupling.
Date: October 30, 2000
Creator: Marinak, M. M.; Kerbel, G. D.; Gentile, N. A.; Jones, O.; Munro, D.; Pollaine, S. et al.
Object Type: Article
System: The UNT Digital Library
Installation of a Hydrologic Characterization Network for Vadose Zone Monitoring of a Single-Shell Tank Farm at the U. S. Department of Energy Hanford Site (open access)

Installation of a Hydrologic Characterization Network for Vadose Zone Monitoring of a Single-Shell Tank Farm at the U. S. Department of Energy Hanford Site

The Pacific Northwest National Laboratory, in collaboration with the Idaho National Engineering and Environmental Laboratory and Duratek Federal Services, deployed a suite of vadose-zone instruments at the B Tank Farm in the 200 E Area of the Hanford Site, near Richland, Washington, during the last quarter of FY 2001. The purpose of the deployment was to obtain in situ hydrologic characterization data within the vadose zone of a high-level-waste tank farm. Eight sensor nests, ranging in depth from 67 m (220 ft) below ground surface (bgs) to 0.9 m (3 ft) bgs were placed in contact with vadose-zone sediments inside a recently drilled, uncased, borehole (C3360) located adjacent to Tank B-110. The sensor sets are part of the Vadose Zone Monitoring System and include advanced tensiometers, heat dissipation units, frequency domain reflectometers, thermal probes, and vadose zone solution samplers. Within the top meter of the surface, a water flux meter was deployed to estimate net infiltration from meteoric water (rain and snowmelt) sources. In addition, a rain gage was located within the tank farm to document on-site precipitation events. All sensor units, with the exception of the solution samplers, were connected to a solar-powered data logger located within the tank …
Date: October 30, 2001
Creator: Gee, Glendon W. (BATTELLE (PACIFIC NW LAB)); Ward, Anderson L. (BATTELLE (PACIFIC NW LAB)); Ritter, Jason C. (BATTELLE (PACIFIC NW LAB)); Sisson, James B. (UNKNOWN); Hubbell, Joel M. (VISITORS) & Sydnor, Harold A. (CH2M HILL HANF GROUP INC)
Object Type: Report
System: The UNT Digital Library
Analysis of Rayleigh-Taylor Instability: Statistics on Rising Bubbles and Falling Spikes (open access)

Analysis of Rayleigh-Taylor Instability: Statistics on Rising Bubbles and Falling Spikes

The analysis of coherent structures in Rayleigh-Taylor simulations is a challenging task as the lack of a precise definition of these structures is compounded by the massive size of the datasets. In an earlier work, we used techniques from image analysis to count these coherent structures in two high-resolution simulations, one a large-eddy simulation with 30 terabytes of analysis data, and the other a direct numerical simulation with 80 terabytes of analysis data. Our analysis indicated that there were four distinct regimes in the process of the mixing of the two fluids, starting from the initial linear stage, followed by the non-linear stage with weak turbulence, the mixing transition stage, and the final stage of strong turbulence. In this paper, we extend our earlier work to focus on only the rising bubbles and the falling spikes. We first consider different ways in which we can constrain the bubble and spike definitions and then extract various statistics on them. Our results on the rising bubble and falling spike counts again show that there are four regimes in the process of fluid mixing, each characterized by an integer-valued slope. Further, the average bubble heights and spike depths are related to similar results …
Date: October 30, 2007
Creator: Kamath, C; Gezahegne, A & Miller, P
Object Type: Report
System: The UNT Digital Library
Electrical insulator requirements for mirror fusion reactors (open access)

Electrical insulator requirements for mirror fusion reactors

The requirements for mirror fusion electrical insulators are discussed. Insulators will be required at the neutral beam injectors, injector power supplies, direct converters, and superconducting magnets. Insulators placed at the neutral beam injectors will receive the greatest radiation exposure, 10/sup 14/ to 10/sup 16/ neutrons/m/sup 2/.s and 0.3 to 3 Gy/s (10/sup 5/ to 10/sup 6/ R/h) of gamma rays, with shielding. Direct converter insulators may receive the highest temperature (up to 1300/sup 0/K), but low voltage holding requirements. Insulators made from organic materials (e.g., plastics) for the magnet coils may be satisfactory. Immediate conductivity increases of all insulators result from gamma irradiation. With an upper limit to gamma flux exposures of 300 Gy/s in a minimally shielded region, the conductivity could reach 10/sup -6/ S/m. Damage from neutron irradiation may not be serious during several years' exposure. Surface changes in ceramics at the neutral beam injector may be serious. The interior of the injector will contain atomic hydrogen, and sputtering may transfer material away from or onto the ceramic insulators. Unknown and potentially damaging interactions between irradiation, electric fields, temperature gradients, cycling of temperature, surface and joint reactions, sputtering, polarization, and electrotransport in the dielectrics are of concern. Materials …
Date: October 30, 1977
Creator: Condit, R. H. & Van Konynenburg, R. A.
Object Type: Report
System: The UNT Digital Library
LOFT CIS Analysis 8''-WW-172-AB inside Penetration S-7A. (open access)

LOFT CIS Analysis 8''-WW-172-AB inside Penetration S-7A.

None
Date: October 30, 1978
Creator: Condie, C. G.
Object Type: Report
System: The UNT Digital Library
Resolving the Formation of Protogalaxies. III.Feedback from the First Stars (open access)

Resolving the Formation of Protogalaxies. III.Feedback from the First Stars

The first stars form in dark matter halos of masses {approx}10{sup 6}M{sub {circle_dot}} as suggested by an increasing number of numerical simulations. Radiation feedback from these stars expels most of the gas from their shallow potential well of their surrounding dark matter halos. We use cosmological adaptive mesh refinement simulations that include self-consistent Population III star formation and feedback to examine the properties of assembling early dwarf galaxies. Accurate radiative transport is modeled with adaptive ray tracing. We include supernova explosions and follow the metal enrichment of the intergalactic medium. The calculations focus on the formation of several dwarf galaxies and their progenitors. In these halos, baryon fractions in 10{sup 8} M{sub {circle_dot}} halos decrease by a factor of 2 with stellar feedback and by a factor of 3 with supernova explosions. We find that radiation feedback and supernova explosions increase gaseous spin parameters up to a factor of 4 and vary with time. Stellar feedback, supernova explosions, and H{sub 2} cooling create a complex, multi-phase interstellar medium whose densities and temperatures can span up to 6 orders of magnitude at a given radius. The pair-instability supernovae of Population III stars alone enrich the halos with virial temperatures of 10{sup …
Date: October 30, 2007
Creator: Wise, John H.; Abel, Tom & /KIPAC, Menlo Park
Object Type: Article
System: The UNT Digital Library
Business System Planning Project, Alternatives Analysis (open access)

Business System Planning Project, Alternatives Analysis

The CHG Chief Information Officer (CIO) requested a study of alternatives to the current business system computing environment. This Business Systems Planning (BSP) Project Alternatives Analysis document presents an analysis of the current Project Controls, Work Management, and Business Management systems environment and alternative solutions that support the business functions. The project team has collected requirements and priorities from stakeholders in each business area and documented them in the BSP System Requirements Specification (SRS), RPP-6297. The alternatives analysis process identifies and measures possible solutions in each of the business process areas against the requirements as documented in the SRS. The team gathered input from both internal and external sources to identify and grade the possible solutions. This document captures the results of that activity and recommends a suite of software products. This study was to select the best product based on how well the product met the requirements, not to determine the platform or hardware environment that would be used. Additional analysis documentation can be found in BSP project files.
Date: October 30, 2000
Creator: EVOSEVICH, S.
Object Type: Report
System: The UNT Digital Library
Catalyzing Inquiry at the Interface of Computing and Biology (open access)

Catalyzing Inquiry at the Interface of Computing and Biology

This study is the first comprehensive NRC study that suggests a high-level intellectual structure for Federal agencies for supporting work at the biology/computing interface. The report seeks to establish the intellectual legitimacy of a fundamentally cross-disciplinary collaboration between biologists and computer scientists. That is, while some universities are increasingly favorable to research at the intersection, life science researchers at other universities are strongly impeded in their efforts to collaborate. This report addresses these impediments and describes proven strategies for overcoming them. An important feature of the report is the use of well-documented examples that describe clearly to individuals not trained in computer science the value and usage of computing across the biological sciences, from genes and proteins to networks and pathways, from organelles to cells, and from individual organisms to populations and ecosystems. It is hoped that these examples will be useful to students in the life sciences to motivate (continued) study in computer science that will enable them to be more facile users of computing in their future biological studies.
Date: October 30, 2005
Creator: Wooley, John & Lin, Herbert S.
Object Type: Text
System: The UNT Digital Library
LOFT CIS analysis 4''-WH-237-E inside containment penetration S-17B (open access)

LOFT CIS analysis 4''-WH-237-E inside containment penetration S-17B

The stress analysis performed on the 4''-WH-237-E piping system inside containment penetration S-17B is presented. Deadweight, thermal expansion, and seismic loads were considered. Results of this analysis show that the subject piping system will meet ASME Code, Section III, Class 2 requirements.
Date: October 30, 1978
Creator: Nitzel, M.E.
Object Type: Report
System: The UNT Digital Library