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Profile modification by the ponderomotive force in spherical targets

Description: Experiments have been performed by LLL which indicate a definite density profile steepening. One possible mechanism for this effect is the ponderomotive force. LASNEX has been modified to include the light momentum deposition in the form rho dv/dt = -nabla P - nabla(radical epsilon + radical 1/epsilon) I/2c. Results will be presented from numerical simulations on spherical glass targets at laser intensities from 10/sup 14/ to 10/sup 16/ watts/cm/sup 2/. Emphasis is placed on the nature of the d… more
Date: October 26, 1977
Creator: Larsen, J. T. & Harte, J.
Partner: UNT Libraries Government Documents Department
open access

Development of superconductors for applications in high-field, high-current-density magnets for fusion research

Description: The development of large-bore, high-field magnets for fusion energy applications requires a system approach to both magnet and conductor design. At Lawrence Livermore National Laboratory (LLNL), the criteria used to choose superconductors include: strain tolerance, radiation tolerance, heat removal, stability, fabricability, and cost. We report on the performance of industrially produced, prototype, Ti-modified Nb/sub 3/Sn wires developed with LLNL support. Wire performance characteristics eval… more
Date: September 26, 1986
Creator: Summers, L. T. & Miller, J. R.
Partner: UNT Libraries Government Documents Department
open access

Exploding pusher targets for the SHIVA laser system

Description: The first targets for the 20 TW SHIVA laser system were designed. They are simple glass micro-balloons, approximately 300 ..mu..m in diameter and 2 ..mu..m thick, filled with D-T gas. Using LASNEX, whose model physics was utilized successfully for ARGUS targets, we optimize for both gain and yield. The target behaves as an exploding pusher. Different simple analytic models for the physics of this mode are presented, and are tested by comparing their scaling predictions, at constant absorbed pow… more
Date: September 26, 1977
Creator: Rosen, M. D.; Larsen, J. T. & Nuckolls, J. H.
Partner: UNT Libraries Government Documents Department
open access

Investigation of strain birefringence and wavefront distortion in 001 plates of KD sub 2 PO sub 4

Description: When 001 plates of KD{sub 2}PO{sub 4} (KD*P) are used in Pockels cells, strain induced refractive index variations result in beam depolarization and transmitted wavefront distortion. The depolarization is determined by the induced birefringence while the wavefront distortion is controlled by the average index shift. Here we show that the birefringence is determined by the shear stress in the xy-plane of the crystal while the average index shift depends only on the normal stresses. Furthermore, … more
Date: August 26, 1991
Creator: De Yoreo, J. J. & Woods, B. W.
Partner: UNT Libraries Government Documents Department
open access

The q q meson states with J sup PC = 2 sup ++ and 0 sup ++

Description: The lowest mesons made up of a light quark and a strange quark produced from a K beam show a good agreement with expectations of the quark model. This good agreement leads to the prediction of the light isoscalar and isovector states and the isoscalar s{bar s} states. Except for one mystery The X(1590) the 2{sup ++} states seems to be well described by the expected ideally mixed q{bar q} states up to 2. 0 GeV. Above 2.0 GeV a new degree of freedom seems to be excited with respect to the breakdo… more
Date: September 26, 1991
Creator: Longacre, R. S.
Partner: UNT Libraries Government Documents Department
open access

Atom-in-jellium models

Description: The author describes in this paper the atom-in-jellium calculations he has been doing over the last ten years. He tries to emphasize reasons for doing this sort of calculations and why he devised a model which is different in some respects from others.
Date: April 26, 1985
Creator: Liberman, D.A.
Partner: UNT Libraries Government Documents Department
open access

Interferometric measurements of multilayer and double shell inertial fusion targets

Description: Optical interference microscopy plays an important role in the measurement of targets for inertial confinement fusion experiments. We describe how these techniques are applied to the measurement of thickness and refractive index of multilayer films on both flat substrates and microsphere targets. We also discuss procedures for manipulating and examining microsphere targets to measure defects and wall thickness variations anywhere on the target. Finally, we describe the use of optical interferom… more
Date: August 26, 1980
Creator: Weinstein, B.W.; Weir, J.T. & Willenborg, D.L.
Partner: UNT Libraries Government Documents Department
open access

Use of molecular beams to support microspheres during plasma coating

Description: Spherical laser fusion targets can be levitated on beams of Ar or other gas atoms. This is an especially useful and reliable technique for supporting microspheres during plasma coating or plasma etching. The reliability of this technique is principally the result of two things: the success of a special centering device which provides a lateral, stabilizing force on the levitated microspheres; and a gas handling system which is capable of controlling levitation gas flow in the microtorr liter/se… more
Date: August 26, 1980
Creator: Crane, J. K.; Smith, R. D.; Johnson, W. L.; Letts, S. A.; Korbel, G. R. & Krenick, R. M.
Partner: UNT Libraries Government Documents Department
open access

Production of slow-positron beams with an electron linac

Description: Intense, pulsed beams of low-energy positrons have been produced by a high-energy beam from an electron linac. The production efficiency for low-energy positrons has been determined for electrons with 60 to 120 MeV energy, low-energy positron beams from a linac can be of much higher intensity than those beams currently derived from radioactive sources.
Date: March 26, 1982
Creator: Howell, R. H.; Alvarez, R. A. & Stanek, M.
Partner: UNT Libraries Government Documents Department
open access

Requirements for a Network Storage Service in a supercomputer environment

Description: Sandia National Laboratories has completed a requirements study for a networked mass storage system. The areas of user functionality, network connectivity, and performance were analyzed to determine specifications for a Network Storage Service to operate in supercomputer environment. 4 refs.
Date: September 26, 1991
Creator: Kelly, S.M.
Partner: UNT Libraries Government Documents Department
open access

Structural Changes Observed in (Mo /sub 6/Ru /sub 4/)/sub x/B/sub 1-x/ Amorphous Alloys Observed with Positron Annihilation

Description: Changes in the structure of (Mo /sub 6/Ru /sub 4/)/sub x/B/sub 1-x/ amorphous alloys were observed in positron annihilation analysis using both positron lifetime and Doppler broadening techniques. The changes were introduced into the alloy either by varying the boron fraction or by neutron irradiation. Similar results were observed both in the irradiated alloys and those with vacant boron sites. The positron annihilation data suggest that the modified structure contains regions of open volume a… more
Date: March 26, 1982
Creator: Howell, R. H. & Johnson, W. L.
Partner: UNT Libraries Government Documents Department
open access

A C programmer's view of a relational database

Description: The AGS Distributed Control System (AGSDCS) uses a relational database (Interbase) for the storage of all data on the host system network. This includes the static data which describes the components of the accelerator complex, as well as data for application program setup and data records that are used in analysis. By creating a mapping of each elation in the database to a C record and providing general tools for relation (record) across, all the data in the database is available in a natural … more
Date: October 26, 1989
Creator: Clifford, T.; Katz, R. & Griffiths, C.
Partner: UNT Libraries Government Documents Department
open access

Mathematical definition of protocol translation

Description: This paper mathematically defines protocol translation which is a function employed to interconnect different computer networks. An example of an application is a gateway.
Date: March 26, 1982
Creator: Ong, M. M.
Partner: UNT Libraries Government Documents Department
open access

The application of the ADSP-21020 40-bit floating point DSP microprocessor in a digital Doppler radar

Description: A continuous wave doppler radar system has been designed which is portable, easily deployable and can be remotely controlled. The system is immune to ground clutter and is used for wind speed detection and direction determination. Nearly real time digital signal processing is performed by an Analog Devices ADSP-21020, a 40-bit floating point Digital Signal Processing (DSP) microprocessor. This paper provides an overview of the design of the system including the radio frequency (RF) to digital i… more
Date: August 26, 1991
Creator: Robinson, S. H. & Morrison, R. E.
Partner: UNT Libraries Government Documents Department
open access

Oklahoma's Residential High School: Cultivating Scholars

Description: First page of an article on the creation of a special residential high school in Oklahoma, wherein Texas is mentioned as a state that has already done so.
Date: October 26, 1987
Partner: Texas Academy of Mathematics and Science
open access

Biomodal spontaneous fission

Description: Investigations of mass and kinetic-energy distributions from spontaneous fission have been extended in recent years to an isotope of element 104 and, for half-lives, to an isotope of element 108. The results have been surprising in that spontaneous fission half-lives have turned out to be much longer than expected and mass and kinetic- energy distributions were found to abruptly shift away from those of the lighter actinides, showing two modes of fission. These new developments have caused a re… more
Date: September 26, 1989
Creator: Hulet, E.K. (Lawrence Livermore National Lab., CA (USA))
Partner: UNT Libraries Government Documents Department
open access

Development of an operational multicomponent personnel neutron dosimeter/spectrometer DOSPEC

Description: A multicomponent dosimeter has been developed that uses an albedo detector to provide the measurement of low energy neutrons and as a screening element. It also contains track detector components, CR-39 and polycarbonate, which are only processed if the TLD indicates there has been an exposure to neutrons. Since the three components have significantly different energy responses, the dosimeter can act as a crude spectrometer. This report describes the dosimeter and briefly summarizes its use exp… more
Date: October 26, 1983
Creator: Griffith, R.V. & McMahon, T.A.
Partner: UNT Libraries Government Documents Department
open access

Fabrication of a Set of Realistic Torso Phantoms for Calibration of Transuranic Nuclide Lung Counting Facilities

Description: A set of 16 tissue equivalent torso phantoms has been fabricated for use by major laboratories involved in counting transuranic nuclides in the lung. These phantoms, which have bone equivalent plastic rib cages, duplicate the performance of the DOE Realistic Phantom set. The new phantoms (and their successors) provide the user laboratories with a highly realistic calibration tool. Moreover, use of these phantoms will allow participating laboratories to intercompare calibration information, both… more
Date: October 26, 1983
Creator: Griffith, R. V.; Anderson, A. L.; Sundbeck, C. W. & Alderson, S. W.
Partner: UNT Libraries Government Documents Department
open access

Control of gas input and background pressure in the end plug regions of the TMX-U thermal barrier experiment

Description: Rate equations for the plasma species in a thermal barrier end plug establish an upper bound on the neutral pressure (P) external to the plasma. For the Tandem Mirror Experiment-Upgrade (TMX-U), this bound is P less than or equal to 0.5 - 1.0 x 10/sup -6/ Torr. Initially TMX-U did not satisfy this criterion, and axial end plugging of plasma losses seemed limited by the excessive pressure. Subsequently, we modified the machine to improve the vacuum conditions, decreasing P to the desired range. … more
Date: October 26, 1983
Creator: Turner, W. C.; Nexsen, W. E.; Allen, S. L.; Hooper, E. B.; Hunt, A. L.; Lang, D. D. et al.
Partner: UNT Libraries Government Documents Department
open access

Rate Dependent Inelastic Behavior of Polycrystalline Solids Using a Dislocation Model

Description: A rate dependent theory of polycrystalline plasticity is presented in which the solid is modeled as an isotropic continuum with internal variables. The rate of plastic deformation is shown to be a function of the deviatoric portion of the Cauchy stress tensor as well as two scalar internal variables. The scalar internal variables, which are the dislocation density and mobile fraction, are governed by rate equations which reflect the evolution of microstructural processes. The model has been inc… more
Date: February 26, 1980
Creator: Werne, R. W. & Kelly, J. M.
Partner: UNT Libraries Government Documents Department
open access

Positron-annihilation studies of molybdenum irradiated by protons, neutrons, or electrons

Description: Annealed molybdenum was irradiated at room temperature by energetic protons or neutrons and the fluence and recoil energy dependence of two traps was measured. Comparison of trapping rates with calculations of damage energy correlates high energy recoils with the short lifetime trap and low energy recoils with the longer lifetime.
Date: March 26, 1982
Creator: Howell, R.H.
Partner: UNT Libraries Government Documents Department
open access

Executive committee report: geotechnical instrumentation working group meeting

Description: Responding to the widespread need for the geotechnical community to discuss instrumentation for nuclear waste repositories, a meeting was held December 2 and 3, 1981, in Denver, Colorado. This report gives the group's consensus recommendations to aid in making decisions for development of instrumentation for future repository work. The main conclusions of the working group meeting were as follows: (1) monitoring of geotechnical parameters in nuclear waste repositories will be necessary to meet … more
Date: April 26, 1982
Creator: Wilder, D. G.; Rogue, F.; Beloff, W. R.; Binnall, E. & Gregory, E. C.
Partner: UNT Libraries Government Documents Department
open access

Liquid to gas leak ratios with liquid nitrogen and liquid helium

Description: To predict the leak rates of liquid helium and liquid nitrogen containers at operating conditions we need to know how small leaks (10/sup -8/ to 10/sup -5/ atm-cm/sup 3/ air/s), measured at standard conditions, behave when flooded with these cryogens. Two small leaks were measured at ambient conditions (approx.750 Torr and 295 K), at the normal boiling points of LN/sub 2/ and LHe, and at elevated pressures above the liquids. The ratios of the leak rates of the liquids at ambient pressure to the… more
Date: February 26, 1985
Creator: Batzer, T. H. & Call, W. R.
Partner: UNT Libraries Government Documents Department
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