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in subjects: "Configuration"

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Excitation of Zonal Flow by Drift Waves in Toroidal Plasmas

An analytical dispersion relation is derived which shows that, in toroidal plasmas, zonal flows can be spontaneously excited via modulations in the radial envelope of a single-n coherent drift wave, with n the toroidal mode number. Predicted instability features are verified by 3D global gyrokinetic simulations of the ion-temperature-gradient mode. Nonlinear equations for mode amplitudes demonstrate saturation of the linearly unstable pump wave and bursting behavior in the drift-wave intensity … more

Date: November 1, 1999

Creator: Chen, L.; White, R. & Lin, Z.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Assembly conductance measurements: halthane vent path testing

The purpose of this test was to characterize the conductance of different configurations of vent paths put into weapons assemblies through application of Halthane 88-3 precoats onto the parts. Conductance is a measure of the ease of gas flow in an assembly. It is the inverse of resistance which may be more familiar to most readers. It is defined as the resultant of the gas flow (torr-1/sec) divided by the pressure drop (torr) in the assembly. Its dimensions are thus liters per second. The condu… more

Date: March 26, 1999

Creator: Beat, T G & Kervin, J E

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Lawrence Livermore National Laboratory hot spot mobile laboratory

Gross alpha/beta/tritium liquid The Hot Spot Mobile Laboratory is an asset used to analyze samples (some high hazard) from the field. Field laboratories allow the quick turnaround of samples needed to establish weapon condition and hazard assessment for the protection of responders and the public. The Hot Spot Lab is configured to fly anywhere in the world and is staffed by expert scientists and technicians from Lawrence Livermore National Laboratory who perform similar functions in their routi… more

Date: August 27, 1999

Creator: Buddemeier, B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Resonant Toroidal Alfven Eigenmodes (RTAEs) in Neutral Beam Heated Reverse Magnetic Shear Plasmas on TFTR

Resonant Toroidal Alfven Eigenmodes (RTAEs) [1, 2] excited by neutral beam ions are observed in the region of the internal transport barrier in enhanced reverse shear (ERS) plasmas on TFTR. These modes occur in multiples of the same toroidal mode number in the range n=2-4 and appear as highly localized structures near the minimum in the q-profile with frequency near to that expected for TAEs. Unlike regular TAEs, these modes are observed in plasmas where the birth velocity of beam ions is well … more

Date: November 1, 1999

Creator: Cheng, C. Z.; G. Y. Fu; Gorelenkov, N. N.; Nazikian, R. & Budny, R. V.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Direct observation of resonance effects in laser cluster interactions

Time resolved dynamics of high intensity laser interactions with atomic clusters have been studied with both theoretical analysis and experiment. A short-pulse Ti:sapphire laser system, which could produce 50 mJ of energy in a 50 fs pulse, was built to perform these experiments. The laser used a novel single grating stretcher and was pumped, in part, by a custom Nd:YLF laser system, including 19 mm Nd:YLF amplifiers. It was found that there is an optimal pulse width to maximize absorption for a… more

Date: June 1, 1999

Creator: Zweiback, J

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department

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Hartree-Fock Mean-Field Models Using Separable Interactions

An effective two-body nuclear interaction is presented which is a sum of terms separable in coordinate space. Calculations are made using this interaction of some doubly closed-shell spherical nuclei using many-body perturbation theory with the Hartree-Fock state as a reference state. It is demonstrated that the interaction gives good bulk properties in finite nuclei.

Date: June 28, 1999

Creator: Stevenson, P.; Stone, J. R. & Strayer, M. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Flaw Stability in Mild Steel Tanks in the Upper-Shelf Ductile Range - Part II: J-Integral Based Fracture Analysis

The J-integral fracture methodology was applied to evaluate the stability of postulated flaws in mild steel storage tanks. The material properties and the J-resistance (JR) curve were obtained from the archival A285 Grade B carbon steel test data. The J-integral calculation is based on the center-cracked panel (CCP) solution of Shih and Hutchinson (1976). A curvature correction was applied to account for the cylindrical shell configuration. A finite element analysis of an arbitrary flaw in the … more

Date: August 31, 1999

Creator: Lam, P.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Field studies of beach cones as coastal erosion control/reversal devices for areas with significant oil and gas activities. Final report, February 24, 1992--September 18, 1995

The primary objective of this project was to evaluate the utility of a device called the {open_quotes}beach cone{close_quotes} in combating coastal erosion. Seven initial sites were selected for testing beach cones in a variety of geometric configurations. Permits were obtained from the State of Louisiana and the U.S. Army Corps of Engineers to perform the work associated with this study. Six hundred beach cones were actually installed at six of the sites in late July and early August, 1992. Fi… more

Date: September 18, 1995

Creator: Law, Victor J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Small-action Particles in a Tokamak in the Presence of an n = 1 Mode

It is found that an m = n = 1 mode with the amplitude exceeding a certain threshold can lead to stochastic motion of energetic ions in tokamaks, the large orbit width particles (potatoes) being most easily affected. An n = 1 mode can redistribute particles also in the absence of stochasticity but only when the perturbation is quickly switched on/off, e.g., due to sawtooth crash. In the latter case, the perturbation results in regular motion of particles around a certain helical orbit, at which … more

Date: November 1, 1999

Creator: White, R. B.; Lutsenko, V. V.; Kolesnichenko, Ya. I. & Yakovenko, Yu. V.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

WinCal system configuration control board (SCCB) operating procedure

This document describes the operating procedure for the System Configuration Control Board (SCCB) performed in support of the Windows Calorimeter Control (WinCal) system. This board will consist of representatives from Babcock & Wilcox Hanford Company Babcock & Wilcox Protec, Inc.; and Lockheed Martin Services, Inc. In accordance with agreements for the joint use of the Babcock & Wilcox Hanford Company calorimeters located in the Hanford Site Plutonium Finishing Plant (PFP) Nondestructive Assay… more

Date: March 26, 1997

Creator: Westsik, G.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Waste package emplacement borehole option study; Yucca Mountain Site Characterization Project

This study evaluates the cost and thermal effects of various waste package emplacement configurations that differ in emplacement orientation, number of containers per borehole, and standoff distance at the potential Yucca Mountain nuclear waste repository. In this study, eight additional alternatives to the vertical and horizontal orientation options presented in the Site Characterization Plan Conceptual Design Report are considered. Typical panel layout configurations based on thermal analysis… more

Date: March 1, 1992

Creator: Streeter, W. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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K-Basins S/RIDS

The Standards/Requirements Identification Document (S/RID) is a list of the Environmental, Safety, and Health (ES{ampersand}H) and Safeguards and Security (SAS) standards/requirements applicable to the K Basins facility.

Date: August 1, 1997

Creator: Watson, D. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Effects of buoyancy on premixed flame stabilization

The stabilization limits of v-flame and conical flames are investigated in normal gravity (+g) and reversed gravity (up-side-down burner, -g) to compare with observations of flame stabilization during microgravity experiments. The results show that buoyancy has most influence on the stabilization of laminar V-flames. Under turbulent conditions, the effects are less significant. For conical flames stabilized with a ring, the stabilization domain of the +g and -g cases are not significantly diffe… more

Date: October 1, 1995

Creator: Bedat, B. & Cheng, R.K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Unsteady Aerodynamics Experiment Phases II-IV Test Configurations and Available Data Campaigns

The main objective of the Unsteady Aerodynamics Experiment is to provide information needed to quantify the full-scale three-dimensional aerodynamic behavior of horizontal axis wind turbines. To accomplish this, an experimental wind turbine configured to meet specific research objectives was assembled and operated at the National Renewable Energy Laboratory (NREL). The turbine was instrumented to characterize rotating blade aerodynamic performance, machine structural responses, and atmospheric … more

Date: August 19, 1999

Creator: Simms, D. A.; Hand, M. M.; Fingersh, L. J. & Jager, D. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Science and Technology of the 10-MA Spherical Tori

The Spherical Torus (ST) configuration has recently emerged as an example of confinement concept innovation that enables attractive steps in the development of fusion energy. The scientific potential for the ST has been indicated by recent encouraging results from START,2 CDX-U, and HIT. The scientific principles for the D-fueled ST will soon be tested by NSTX (National Spherical Torus Experiment3) in the U.S. and MAST (Mega-Amp Spherical Tokamak4) in the U.K. at the level of l-2 MA in plasma c… more

Date: November 14, 1999

Creator: Peng, Y-K.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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b{bar b} production correlations, b{bar b} mixing and {epsilon}{sub B} at CDF

We present preliminary measurements of b{bar b} production correlations, the average B{bar B} mixing, and a limit on the CP violating parameter {epsilon}{sub b} using dimuon events from the dual semileptonic decay of b{bar b}. Data used in this analysis was taken during the 1992--1993 CDF run of the Fermilab Tevatron collider with an integrated luminosity of 17.4 {plus_minus} 0.6 pb{sup {minus}1}. The results on b{bar b} production correlations are compared to predictions of next-to-leading ord… more

Date: July 1, 1995

Creator: Abe, F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Helicon Plasma Source Configuration Analysis by Means of Density Measurements

Initial results have been obtained from operation of a helicon plasma source built to conduct optimization studies for space propulsion applications. The source features an easily reconfigurable antenna to test different geometries. Operating with He as the source gas, peak densities >= 1.6X10{sup 19} m{sup -3} have been achieved. Radial and axial plasma profiles have been obtained using a microwave interferometer that can be scanned axially and a Langmuir probe. The source will be used to i… more

Date: November 13, 1999

Creator: Angrilli, F.; Barber, G. C.; Carter, M. D.; Goulding, R. H.; Maggiora, R.; Pavarin, D. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Properties of High Beta, Quasi-Axisymmetric NCSX Stellarator Configurations

Quasi-axisymmetry, external kinks and ballooning stability are studied with respect to the plasma shaping and variation in the pressure and current profiles for NCSX. We show that while the kink stability may require a delicate boundary shaping, most quasi-axisymmetry may be achieved using a few low order modes that eliminate the large mirror fields arising partly from boundary shaping for the kink stability. In addition, we demonstrate that the kink and ballooning instability may be improved i… more

Date: September 28, 1999

Creator: Boozer, A.; Fu, G. Y.; Ku, L. P.; Monticello, D. & Reiman, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Liquid Lithium Wall Experiments in CDX-U

The concept of a flowing lithium first wall for a fusion reactor may lead to a significant advance in reactor design, since it could virtually eliminate the concerns with power density and erosion, tritium retention, and cooling associated with solid walls. Sputtering and erosion tests are currently underway in the PISCES device at the University of California at San Diego (UCSD). To complement this effort, plasma interaction questions in a toroidal plasma geometry will be addressed by a propos… more

Date: October 1, 1999

Creator: Doerner, R.; Kaita, R.; Majeski, R.; Luckhardt, S. & al, et

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

ICRF heating on helical devices

Ion cyclotron range of frequency (ICRF) heating is currently in use on CHS and W7AS and is a major element of the heating planned for steady state helical devices. In helical devices, the lack of a toroidal current eliminates both disruptions and the need for ICRF current drive, simplifying the design of antenna structures as compared to tokamak applications. However the survivability of plasma facing components and steady state cooling issues are directly applicable to tokamak devices. Results… more

Date: September 1, 1995

Creator: Rasmussen, D.A.; Lyon, J.F. & Hoffman, D.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A numerical study of shock-acceleration of a diffuse helium cylinder. Revision 1

The development of a shock-accelerated diffuse Helium cylindrical inhomogeneity is investigated using a new numerical method. The new algorithm is a higher-order Godunov implementation of the so-called multi-fluid equations. This system correctly models multiple component mixtures by accounting for differential compressibility effects. This base integrator is embedded in an implementation of adaptive mesh refinement (AMR) that allows efficient increase in resolution by concentrating the computa… more

Date: August 1, 1995

Creator: Greenough, J.A. & Jacobs, J.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Rayleigh-Taylor instability experiments in a cylindrically convergent geometry

Due to the sensitivity of Rayleigh-Taylor instabilities to initial conditions and due to the difficulty of forming well controlled cylindrical or spherical fluid interfaces, Rayleigh-Taylor experiments are often performed with simple, planar interfaces. Rayleigh-Taylor instability phenomena of practical interest, however, (e.g., underwater explosions, supernova core collapses, and inertial confinement fusion capsule implosions) are typically associated with cylindrical or spherical interfaces i… more

Date: August 25, 1995

Creator: Goodwin, B. & Weir, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Development of adaptive resonator techniques for high-power lasers

The design of an adaptive wavefront control system for a high-power Nd:Glass laser will be presented. Features of this system include: an unstable resonator in confocal configuration, a multi-module slab amplifier, and real-time intracavity adaptive phase control using deformable mirrors and high-speed wavefront sensors. Experimental results demonstrate the adaptive correction of an aberrated passive resonator (no gain).

Date: July 12, 1999

Creator: An, J.; Brase, J.; Carrano, C.; Dane, C. B.; Flath, L.; Fochs, S. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Field emission from carbon films deposited by VHF CVD on difference substrates

As previously demonstrated, non-diamond carbon (NDC) films deposited at low temperatures 200-300 C on silicon tips reduced the threshold of field emission. In this paper we will present the results of the study of field emission from flat NDC films prepared by VHF CVD. Emission measurements were performed in a diode configuration at approximately 10{sup {minus}10} Torr. NDC films were deposited on ceramic and on c-Si substrates sputter coated with layers of Ti, Cu, Ni and Pt. The back contact m… more

Date: April 1, 1999

Creator: Abramov, A A; Andronov, A N; Felter, T E; Ioffe, A F; Kosarev, A I; Shotov, M V et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department