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NIF optics

Description: One of the major highlights of the technology development for the National Ignition Facility (NIF) is the optics. NIF will be the largest laser ever built, requiring 7500 large optics (over one foot across) and more than 30,000 small optics. The design, manufacture, and assembly of these important pieces have called for innovative ways to make optics of higher quality than ever before, and to do so at unprecedented speeds. The most obvious role of NIF optics is to steer the 192 laser beams thro… more
Date: August 30, 2000
Creator: Parham, T
Partner: UNT Libraries Government Documents Department
open access

Development of techniques in magnetic resonance and structural studies of the prion protein

Description: Magnetic resonance is the most powerful analytical tool used by chemists today. Its applications range from determining structures of large biomolecules to imaging of human brains. Nevertheless, magnetic resonance remains a relatively young field, in which many techniques are currently being developed that have broad applications. In this dissertation, two new techniques are presented, one that enables the determination of torsion angles in solid-state peptides and proteins, and another that in… more
Date: July 1, 2000
Creator: Bitter, Hans-Marcus L.
Partner: UNT Libraries Government Documents Department
open access

Novel nuclear magnetic resonance techniques for studying biological molecules

Description: Over the fifty-five year history of Nuclear Magnetic Resonance (NMR), considerable progress has been made in the development of techniques for studying the structure, function, and dynamics of biological molecules. The majority of this research has involved the development of multi-dimensional NMR experiments for studying molecules in solution, although in recent years a number of groups have begun to explore NMR methods for studying biological systems in the solid-state. Despite this new effor… more
Date: June 1, 2000
Creator: Laws, David D.
Partner: UNT Libraries Government Documents Department
open access

Measurement of the neutron spin structure function at low Q{sup 2}

Description: The spin dependent cross sections, {sigma}{sup T}{sub 1/2} and {sigma}{sup T}{sub 3/2}, and asymmetries, A{sub {parallel}} and A{sub {perp}}, for {sup 3}He have been measured at the Jefferson Lab's Hall A facility. The inclusive scattering process {sup 3}{vec He}({vec e},e)X was performed for initial beam energies ranging from 0.86 to 5.1 GeV, at a scattering angle of 15.5°. Data includes measurements from the quasielastic peak, resonance region, and the deep inelastic regime. An approximation … more
Date: August 1, 2000
Creator: Jensen, John Steffen
Partner: UNT Libraries Government Documents Department
open access

Study of the Axial Anomaly using the {gamma}p {yields} {pi}{sup +}P{pi}{sup 0} n Reaction Near Threshold

Description: This experiment was one of the first photoproduction experiments performed at Jefferson Lab using the CLAS and the Photon Tagger. The event reconstruction and the photon flux determination procedures have been developed and were proven to work well as we can see from the cross section measurement of the {gamma}p {yields} {pi}{sup +}n reaction. The preliminary results at CLAS for this reaction agree very well with previous world data. The analysis procedure has been developed to analyze the doub… more
Date: May 1, 2000
Creator: Asavapibhop, Burin
Partner: UNT Libraries Government Documents Department
open access

A Scaled Final Focus Experiment for Heavy Ion Fusion

Description: A one-tenth dimensionally scaled version of a final focus sub-system design for a heavy ion fusion driver is built and tested. By properly scaling the physics parameters that relate particle energy and mass, beam current, beam emittance, and focusing field, the transverse dynamics of a driver scale final focus are replicated in a small laboratory beam. The experiment uses a 95 {micro}A beam of 160 keV Cs{sup +} ions to study the dynamics as the beam is brought to a ballistic focus in a lattice … more
Date: September 19, 2000
Creator: MacLaren, Stephan, Alexander
Partner: UNT Libraries Government Documents Department
open access

Development of Trivalent Ytterbium Doped Fluorapatites for Diode-Pumped Laser Applications

Description: One of the major motivators of this work is the Mercury Project, which is a 1 kW scalable diode-pumped solid-state laser system under development at Lawrence Livermore National Laboratory (LLNL). Major goals include 100 J pulses, 10% wallplug efficiency, 10 Hz repetition rate, and a 5 times diffraction limited beam. To achieve these goals the Mercury laser incorporates ytterbium doped Sr{sub 5}(PO{sub 4}){sub 3}F (S-FAP) as the amplifier gain medium. The primary focus of this thesis is a full u… more
Date: June 21, 2000
Creator: Bayramian, A. J.
Partner: UNT Libraries Government Documents Department
open access

Benchmarks and models for 1-D radiation transport in stochastic participating media

Description: Benchmark calculations for radiation transport coupled to a material temperature equation in a 1-D slab and 1-D spherical geometry binary random media are presented. The mixing statistics are taken to be homogeneous Markov statistics in the 1-D slab but only approximately Markov statistics in the 1-D sphere. The material chunk sizes are described by Poisson distribution functions. The material opacities are first taken to be constant and then allowed to vary as a strong function of material tem… more
Date: August 21, 2000
Creator: Miller, D. S.
Partner: UNT Libraries Government Documents Department
open access

Object-oriented algorithmic laboratory for ordering sparse matrices

Description: We focus on two known NP-hard problems that have applications in sparse matrix computations: the envelope/wavefront reduction problem and the fill reduction problem. Envelope/wavefront reducing orderings have a wide range of applications including profile and frontal solvers, incomplete factorization preconditioning, graph reordering for cache performance, gene sequencing, and spatial databases. Fill reducing orderings are generally limited to--but an inextricable part of--sparse matrix factori… more
Date: May 1, 2000
Creator: Kumfert, G K
Partner: UNT Libraries Government Documents Department
open access

NIF program management

Description: No Description Available.
Date: September 15, 2000
Creator: Carpenter, J & Warner, B
Partner: UNT Libraries Government Documents Department
open access

NIF frequently asked questions

Description: The Stockpile Stewardship Program is an initiative to maintain the nuclear deterrent of the United States in the post-Cold War era. It is based on the maintenance of our stockpile through an ongoing process of surveillance, assessment, refurbishment, and recertification, without nuclear testing. At the heart of the SSP is an attempt to bring advanced experimental and computational tools to bear on the evaluation and certification of the stockpile itself; these advanced scientific capabilities a… more
Date: September 15, 2000
Creator: Carpenter, J & Warner, B
Partner: UNT Libraries Government Documents Department
open access

Cooling of highly charged ions in a Penning trap

Description: Highly charged ions are extracted from an electron beam ion trap and guided to Retrap, a cryogenic Penning trap, where they are merged with laser cooled Be{sup +} ions. The Be{sup +} ions act as a coolant for the hot highly charged ions and their temperature is dropped by about 8 orders of magnitude in a few seconds. Such cold highly charged ions form a strongly coupled nonneutral plasma exhibiting, under such conditions, the aggregation of clusters and crystals. Given the right mixture, these … more
Date: March 31, 2000
Creator: Gruber, L
Partner: UNT Libraries Government Documents Department
open access

Microcalorimetry and the transition-edge sensor

Description: Many scientific and industrial applications call for quantum-efficient high-energy-resolution microcalorimeters for the measurement of x rays. The applications driving the development of these detectors involve the measurement of faint sources of x rays in which few photons reach the detector. Interesting astrophysical applications for these microcalorimeters include the measurement of composition and temperatures of stellar atmospheres and diffuse interstellar plasmas. Other applications of mi… more
Date: April 1, 2000
Creator: Lindeman, M A
Partner: UNT Libraries Government Documents Department
open access

NIF and science

Description: The National Ignition Facility (NIF) will have many uses besides its primary mission in the US Department of Energy's Stockpile Stewardship Program. It will provide a broad array of applications to basic science, and will also play an important role in the development of commercial fusion energy.
Date: September 15, 2000
Creator: Carpenter, J & Warner, B
Partner: UNT Libraries Government Documents Department
open access

Inertial fusion technology spin-offs-history provides a glimpse of the future

Description: The development and demonstration of inertial fusion is incredibly challenging because it requires simultaneously controlling and precisely measuring parameters at extreme values in energy, space, and time. The challenges range from building megajoule (10{sup 6} J) drivers that perform with percent-level precision to fabricating targets with submicron specifications to measuring target performance at micron scale (10{sup -6} m) with picosecond (10{sup -12} s) time resolution. Over the past 30 y… more
Date: March 7, 2000
Creator: Powell, H
Partner: UNT Libraries Government Documents Department
open access

Kinetics of (beta)(right arrow)(delta) Solid-Solid Phase Transition of HMX

Description: In order to calculate the kinetic parameters from DSC data, we have used the generally accepted methods of Bershtein [13]. We have calculated the rate constants for 4 temperatures and the activation energy based on the shift in the transition temperature, {beta} {yields} {delta} for HMX. The values of E{sub a} from this work is 402 kJ/mol compared to previous results by Brill [9] of 204 kJ/mol. Brill and associates measured the phase transition of HMX using FTIR, sodium chloride plates and sili… more
Date: September 1, 2000
Creator: Weese, R K
Partner: UNT Libraries Government Documents Department
open access

Inertial Conference Fusion Semiannual Report October 1999 - March 2000, Volume 1, Number 1

Description: This first issue of the ''ICF Semiannual Report'' contains articles whose diverse subjects attest to the broad technical and scientific challenges that are at the forefront of the ICF program at LLNL. The first article describes the progress being made at solving the surface roughness problem on capsule mandrels. All NIF capsule options, except machined beryllium, require a mandrel upon which the ablator is deposited. This mandrel sets the baseline sphericity of the final capsule. Problems invo… more
Date: March 1, 2000
Creator: Hammel, B. A.
Partner: UNT Libraries Government Documents Department
open access

Lasershot peening--a means to strengthen metals

Description: Lasershot peening is an emerging modern process that impresses a compressive stress into the surfaces of metals, improving their operational lifetime. Almost everyone is familiar with taking a strip of metal or a wire and bending it multiple times until it breaks. In this situation, when the metal is bent, the surface of outer radius is stretched into a tensile state. Under tension, any flaw or micro-crack will grow in size with each bending of the metal until the crack grows through the entire… more
Date: March 1, 2000
Creator: Chen, H. L.
Partner: UNT Libraries Government Documents Department
open access

NIF facts

Description: The National Ignition Facility (NIF) will use the world's largest laser to compress and heat BB-sized capsules of fusion fuel to thermo-nuclear ignition. NIF experiments will produce temperatures and densities like those in the Sun or in an exploding nuclear weapon. The experiments will help scientists sustain confidence in the nuclear weapon stockpile without nuclear tests as a unique element of the DOE'S Stockpile Stewardship Program and will produce additional benefits in basic science and f… more
Date: September 8, 2000
Creator: Carpenter, J & Warner, B
Partner: UNT Libraries Government Documents Department
open access

Electron-capture delayed fission properties of neutron-deficient einsteinium nuclei

Description: Electron-capture delayed fission (ECDF) properties of neutron-deficient einsteinium isotopes were investigated using a combination of chemical separations and on-line radiation detection methods. {sup 242}Es was produced via the {sup 233}U({sup 14}N,5n){sup 242}Es reaction at a beam energy of 87 MeV (on target) in the lab system, and was found to decay with a half-life of 11 {+-} 3 seconds. The ECDF of {sup 242}Es showed a highly asymmetric mass distribution with an average pre-neutron emission… more
Date: January 5, 2000
Creator: Shaughnessy, Dawn A.
Partner: UNT Libraries Government Documents Department
open access

A measurement of t{anti t} production cross section in p{anti p} collisions at {radical}s = 1.8 TeV using neural networks

Description: The authors present the results of a new measurement of the t{anti t} production cross section using e{mu} channel in p{anti p} collisions at {radical}s = 1.8 TeV. This study corresponds to an integrated luminosity of 108.3 {+-} 5.7 pb{sup {minus}1} acquired by the D0 detector during the Fermilab Tevatron Collider Run 1 (1992--1996). By using neural network techniques instead of the conventional analysis methods, the authors show that the signal acceptance can be increased by 10% (for m{sub t} … more
Date: June 16, 2000
Creator: Singh, Harpreet
Partner: UNT Libraries Government Documents Department
open access

An implicit Smooth Particle Hydrodynamic code

Description: An implicit version of the Smooth Particle Hydrodynamic (SPH) code SPHINX has been written and is working. In conjunction with the SPHINX code the new implicit code models fluids and solids under a wide range of conditions. SPH codes are Lagrangian, meshless and use particles to model the fluids and solids. The implicit code makes use of the Krylov iterative techniques for solving large linear-systems and a Newton-Raphson method for non-linear corrections. It uses numerical derivatives to const… more
Date: April 1, 2000
Creator: Knapp, Charles E.
Partner: UNT Libraries Government Documents Department
open access

Search for single top production with the D0 detector at the Fermilab Tevatron Collider

Description: We attempt to identify a single top signal in the muon + jets data collected using the D0 detector at the Fermilab Tevatron at a center-of-mass energy of {radical}s = 1.8 TeV from 1992-96. The data corresponds to an integrated luminosity of 103.7 pb{sup -1}. While resolving a signal has proved impossible, we are able to place an upper limit on the production cross section for single top events using these data. The cross section for production of single top via 95% p{bar p} {yields} tb and p{ba… more
Date: June 15, 2000
Creator: McDonald, J. E.
Partner: UNT Libraries Government Documents Department
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