Simulating Marvel with the Stun Code (open access)

Simulating Marvel with the Stun Code

MARVEL, a nuclear-driven shock-tube experiment, consisted of a 2.2 kiloton nuclear explosive detonated 176 meters underground at one end of a 122-meter long, 1-meter diameter horizontal tunnel. Vaporization of material in the immediate vicinity of the explosive provided the source of high-energy driver gas. The driven gas was the ambient atmospheric air in the tunnel. The event was staged as an experimental and calculational study of the time dependent .ow of energy in the tunnel and surrounding alluvium. In this report we describe the derivation and implementation of a ''1-3/4D'' hydrocode to simulate the experiment. Calculations were performed to study the influence of energy transport to, and mass ablation from, the walls of the tunnel on the shock velocity.
Date: May 23, 2001
Creator: Glenn, L A
Object Type: Report
System: The UNT Digital Library
High Average Power Yb:YAG Laser (open access)

High Average Power Yb:YAG Laser

We are working on a composite thin-disk laser design that can be scaled as a source of high brightness laser power for tactical engagement and other high average power applications. The key component is a diffusion-bonded composite comprising a thin gain-medium and thicker cladding that is strikingly robust and resolves prior difficulties with high average power pumping/cooling and the rejection of amplified spontaneous emission (ASE). In contrast to high power rods or slabs, the one-dimensional nature of the cooling geometry and the edge-pump geometry scale gracefully to very high average power. The crucial design ideas have been verified experimentally. Progress this last year included: extraction with high beam quality using a telescopic resonator, a heterogeneous thin film coating prescription that meets the unusual requirements demanded by this laser architecture, thermal management with our first generation cooler. Progress was also made in design of a second-generation laser.
Date: May 23, 2001
Creator: Zapata, L E; Beach, R J & Payne, S A
Object Type: Article
System: The UNT Digital Library
Generic Degraded Congiguration Probability Analysis for DOE Codisposal Waste Package (open access)

Generic Degraded Congiguration Probability Analysis for DOE Codisposal Waste Package

In accordance with the technical work plan, ''Technical Work Plan For: Department of Energy Spent Nuclear Fuel Work Packages'' (CRWMS M&O 2000c), this Analysis/Model Report (AMR) is developed for the purpose of screening out degraded configurations for U.S. Department of Energy (DOE) spent nuclear fuel (SNF) types. It performs the degraded configuration parameter and probability evaluations of the overall methodology specified in the ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2000, Section 3) to qualifying configurations. Degradation analyses are performed to assess realizable parameter ranges and physical regimes for configurations. Probability calculations are then performed for configurations characterized by k{sub eff} in excess of the Critical Limit (CL). The scope of this document is to develop a generic set of screening criteria or models to screen out degraded configurations having potential for exceeding a criticality limit. The developed screening criteria include arguments based on physical/chemical processes and probability calculations and apply to DOE SNF types when codisposed with the high-level waste (HLW) glass inside a waste package. The degradation takes place inside the waste package and is long after repository licensing has expired. The emphasis of this AMR is on degraded configuration screening and the probability analysis is one of …
Date: May 23, 2001
Creator: Deng, S.F.A.; Saglam, M. & Gratton, L.J.
Object Type: Report
System: The UNT Digital Library
U.S. Department of Energy and Polish Institute for Ecology of Industrial Areas Joint Coordinating Committee for Environmental Systems FY00 Annual Report (open access)

U.S. Department of Energy and Polish Institute for Ecology of Industrial Areas Joint Coordinating Committee for Environmental Systems FY00 Annual Report

The complexity of environmental pollution, not reported all over the world, increases the demand for novel, highly efficient and cost-effective rehabilitation technologies.
Date: May 23, 2001
Creator: Altman, D. J.
Object Type: Report
System: The UNT Digital Library
Nonlinear Gyroviscous Force in a Collisionless Plasma (open access)

Nonlinear Gyroviscous Force in a Collisionless Plasma

Nonlinear gyroviscous forces in a collisionless plasma with temperature variations are calculated from the gyrofluid moments of the gyrokinetic Vlasov equation. The low-frequency gyrokinetic ordering and electrostatic perturbations are assumed, and an additional finite Larmor radius (FLR) expansion is performed. This approach leads naturally to an expression for the gyroviscous force in terms of the gyrocenter distribution function, thus including all resonant effects, and represents a systematic FLR expansion in a general form (no assumption of any closure is made). The expression for the gyroviscous force is also calculated in terms of the particle-fluid moments by making the transformation from the gyrocenter to particle coordinates. The calculated expression represents a modification of the Braginskii gyroviscosity for a collisionless plasma with nonuniform temperature. It is compared with previous calculations based on the traditional fluid approach. As a byproduct of the gyroviscosity calculations, we derive a set of nonlinear reduced gyrofluid (and a corresponding set of particle-fluid) moment equations with FLR corrections, which exhibit a generalized form of the ''gyroviscous cancellation.''
Date: May 23, 2001
Creator: Belova, E. V.
Object Type: Report
System: The UNT Digital Library
Theoretical study of lesion detectability of MAP reconstruction using computer observers (open access)

Theoretical study of lesion detectability of MAP reconstruction using computer observers

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Date: May 23, 2001
Creator: Qi, Jinyi & Huesman, Ronald H.
Object Type: Article
System: The UNT Digital Library
From surface roughening to QCD string theory (open access)

From surface roughening to QCD string theory

Surface critical phenomena and the related onset of Goldstone modes represent fundamental properties of the confining flux in Quantum Chromodynamics. New ideas on surface roughening and their implications for lattice studies of quark confinement and string formation are presented. Problems with a simple string description of the large Wilson surface are discussed.
Date: May 23, 2001
Creator: al., Keisuke Jimmy Juge et
Object Type: Article
System: The UNT Digital Library
Wind Powering America: America's Wind Power...A Natural Resource (open access)

Wind Powering America: America's Wind Power...A Natural Resource

The Wind Powering America Initiative is a regionally-based effort to increase the use of clean wind energy in the United States over the next two decades. The purpose of this brochure is to provide a brief description of the initiative, its goals, benefits, and strategy as well as a list of contacts for those interested in obtaining more information.
Date: May 23, 2001
Creator: Dougherty, P.
Object Type: Book
System: The UNT Digital Library
Clean Cities Coalition Awards: Clean Cities Alternative Fuel Information Series Fact Sheet (open access)

Clean Cities Coalition Awards: Clean Cities Alternative Fuel Information Series Fact Sheet

A fact sheet that introduces the winners of the 2001 Clean Cities coalition awards, including the Empire, Movers and Shakers, Gold Star, Few Good Fleets and Madison Avenue awards.
Date: May 23, 2001
Creator: LaRocque, T.
Object Type: Book
System: The UNT Digital Library
Rare and forbidden decays of D Mesons (open access)

Rare and forbidden decays of D Mesons

The authors summarize the results of two recent searches for flavor-changing neutral current, lepton-flavor violating, and lepton-number violating decays of D{sup +}, D{sub s}{sup +}, and D{sup 0} mesons (and their antiparticles) into modes containing muons and electrons. using data from Fermilab charm hadroproduction experiment E791, they examined D{sup +} and D{sub s}{sup +} {pi}{ell}{ell} and {Kappa}{ell}{ell} decay modes and the D{sup 0} dilepton decay modes containing either {ell}{sup +}{ell}{sup {minus}}, a {rho}{sup 0}, {bar {Kappa}}*{sup 0}, or {phi} vector meson, or a non-resonant {pi}{pi}, {Kappa}{pi}, or {Kappa}{Kappa} pair of pseudoscalar mesons. No evidence for any of these decays was found. Therefore, the authors presented branching-fraction upper limits at 90% confidence level for the 51 decay modes examined. Twenty-six of these modes had no previously reported limits, and eighteen of the remainder were reported with significant improvements over previously published results.
Date: May 23, 2001
Creator: al., David A. Sanders et
Object Type: Article
System: The UNT Digital Library