149 Matching Results

Search Results

Results: 1 - 24 next
open access

Design studies of a laser fusion power plant

Description: The conceptual design of a laser fusion power plant has been undertaken to exploit recent developments in target design. Advanced high-gain targets which have been developed make it possible to significantly relax the laser and optical system requirements. The power plant design features a reactor concept which utilizes a thick falling region of liquid lithium to protect the first-wall from the neutrons, x-rays, and charged particles that are produced in the thermonuclear microexplosion. The li… more
Date: October 7, 1977
Creator: Maniscalco, J. A.; Meier, W. R. & Monsler, M. J.
Partner: UNT Libraries Government Documents Department
open access

MTX (Microwave Tokamak Experiment) facility and machine grounding plan

Description: A key issue in the design of fusion research experiments and their related facilities is the control of ground currents. Because of the large magnetic field, high voltages and high currents present in most of these installations, it is essential to avoid ground loops, and to control ground currents during both normal operations and fault conditions. This paper describes the grounding policy that was developed for MTX. The vault area was divided into zones, and each of the four walls was treated… more
Date: October 7, 1987
Creator: Bell, H.H.; Rice, B.W.; Petersen, D.E. & Herrera, C.H.
Partner: UNT Libraries Government Documents Department
open access

Magnet power system for the Microwave Tokamak Experiment (MTX)

Description: The system configuration, layout, and general philosophy for the MTX magnet power system is described. The vast majority of the magnet power equipment was quite successfully used on the ALCATOR-C experiment at the Massachusetts Institute of Technology. The AC power for the magnet system at MIT was obtained from a 225MVA alternator. The power for the system at LLNL is obtained directly from the local utility's 230 kV line. This installation, therefore, necessitates the addition of a great deal o… more
Date: October 7, 1987
Creator: Jackson, M.C. & Musslewhite, R.C.
Partner: UNT Libraries Government Documents Department
open access

Analysis of three-phase power-supply systems using computer-aided design programs

Description: A major concern of every designer of large, three-phase power-supply systems is the protection of system components from overvoltage transients. At present, three computer-aided circuit design programs are available in the Magnetic Fusion Energy (MFE) National Computer Center that can be used to analyze three-phase power systems: MINI SCEPTRE, SPICE I, and SPICE II. These programs have been used at Lawrence Livermore Laboratory (LLL) to analyze the operation of a 200-kV dc, 20-A acceleration po… more
Date: October 7, 1977
Creator: Oberst, E.F.
Partner: UNT Libraries Government Documents Department
open access

Automated supernova search

Description: A program is described for development of an automated supernova search based upon complete remote computer control of a telescope and vidicon digital imaging system. (GHT)
Date: October 7, 1981
Creator: Colgate, S. A.
Partner: UNT Libraries Government Documents Department
open access

High-field superconducting solenoids for the TIBER II PF (poloidal-field) system

Description: The poloidal-field (PF) coil set for the Tokamak Ignition/Burn Engineering Reactor (TIBER-II) consists of 24 solenoid modules, 16 of which are stacked inside the toroidal-field (TF) system at the center of the machine. These central solenoid modules operate at high-current densities, and maximum fields at the windings approach 14 T. Although TIBER-II is designed for steady-state operation with noninductive current drive, other operating scenarios are also considered. In the pulsed or inductive … more
Date: October 7, 1987
Creator: Kerns, J. A.; Miller, J. R. & Summers, L. T.
Partner: UNT Libraries Government Documents Department
open access

TIBER-II TF (toroidal-field) winding pack design

Description: The superconducting, toroidal-field (TF) coils in the Tokamak Ignition/Burn Engineering Reactor (TIBER II) are designed with cable-in-conduit conductor (CICC) using Nb/sub 3/Sn composite strands. To design the CICC winding pack, we used an optimization technique that maximizes the conductor stability without violating the constraints imposed by the structure, electrical insulation, quench protection, and fabrication technique. Detailed helium-properties codes calculate the heat removal along a … more
Date: October 7, 1987
Creator: Kerns, J. A.; Miller, J. R.; Slack, D. S. & Summers, L. T.
Partner: UNT Libraries Government Documents Department
open access

Oxidation and aging in U and Pu probed by spin-orbit sum rule analysis: indications for covalent metal-oxide bonds

Description: Transmission electron microscopy is used to acquire electron energy-loss spectra from phase-specific regions of Pu and U metal, PuO{sub 2} and UO{sub 2}, and aged, self-irradiated Pu metal. The N{sub 4,5} (4d {yields} 5f) spectra are analyzed using the spin-orbit sum rule. Our results show that the technique is sensitive enough to detect changes in the branching ratio of the white-line peaks between the metal and dioxide of both U and Pu. There is a small change in the branching ratio between d… more
Date: October 7, 2005
Creator: Moore, K.; van der Laan, G.; Haire, R.; Wall, M. & Schwartz, A.
Partner: UNT Libraries Government Documents Department
open access

Data Association and Bullet Tracking Algorithms for the Fight Sight Experiment

Description: Previous LLNL investigators developed a bullet and projectile tracking system over a decade ago. Renewed interest in the technology has spawned research that culminated in a live-fire experiment, called Fight Sight, in September 2005. The experiment was more complex than previous LLNL bullet tracking experiments in that it included multiple shooters with simultaneous fire, new sensor-shooter geometries, large amounts of optical clutter, and greatly increased sensor-shooter distances. This prese… more
Date: October 7, 2005
Creator: Breitfeller, E & Roberts, R
Partner: UNT Libraries Government Documents Department
open access

Flow of mantle fluids through the ductile lower crust: Heliumisotope trends

Description: Heat and mass are injected into the shallow crust when mantle fluids are able to flow through the ductile lower crust. Minimum 3He/4He ratios in surface fluids from the northern Basin and Range province, western North America increase systematically from low, crustal values in the east to high, mantle values in the west, a regional trend that correlates with the rates of active crustal deformation. The highest ratios occur where the extension and shear strain rates are greatest. The corresponde… more
Date: October 7, 2007
Creator: Kennedy, B. Mack & van Soest, Matthijs C.
Partner: UNT Libraries Government Documents Department
open access

Time-resolved imaging of current-induced domain-wall oscillations

Description: Current-induced domain-wall dynamics is investigated via high-resolution soft x-ray transmission microscopy by a stroboscopic pump-and-probe measurement scheme at a temporal resolution of 200 ps. A 180{sup o} domain wall in a restoring potential of a permalloy microstructure is displaced from its equilibrium position by nanosecond current pulses leading to oscillations with velocities up to 325 m/s. The motion of the wall is described with an analytical model of a rigid domain wall in a nonharm… more
Date: October 7, 2008
Creator: Bocklage, Lars; Krueger, Benjamin; Eiselt, Rene; Bolte, Markus; Fischer, Peter & Meier, Guido
Partner: UNT Libraries Government Documents Department
open access

Measures of microstructure to improve estimates and bounds on elastic constants and transport coefficients in heterogeneous media

Description: The most commonly discussed measures of microstructure in composite materials are the spatial correlation functions, which in a porous medium measure either the grain-to-grain correlations, or the pore-to-pore correlations in space. Improved bounds based on this information such as the Beran-Molyneux bounds for bulk modulus and the Beran bounds for conductivity are well-known. It is first shown here how to make direct use of this information to provide estimates that always lie between these up… more
Date: October 7, 2004
Creator: Berger, E. L.
Partner: UNT Libraries Government Documents Department
open access

Linear scaling first-principles molecular dynamics with plane waves accuracy

Description: We propose a real-space finite differences approach for accurate and unbiased O(N) Density Functional Theory molecular dynamics simulations based on a localized orbitals representation of the electronic structure. The discretization error can be reduced systematically by adapting the mesh spacing, while the orbitals truncation error decreases exponentially with the radius of the localization regions. For regions large enough, energy conservation in microcanonical simulations is demonstrated for… more
Date: October 7, 2005
Creator: Fattebert, J. & Gygi, F.
Partner: UNT Libraries Government Documents Department
open access

Cable-in-conduit conductor optimization for fusion magnet applications

Description: Careful design of the toroidal-field (TF) and poloidal-field (PF) coils in a tokamak machine using cable-in-conduit conductors (CICC) can result in quite high overall winding-pack current densities - even with the high nuclear heat loads that may be imposed in operating a fusion reactor - and thereby help reduce the overall machine size. In our design process, we systematically examined the operational environment of a magnet, e.g., mechanical stresses, current, field, heat load, coolant temper… more
Date: October 7, 1987
Creator: Miller, J. R. & Kerns, J. A.
Partner: UNT Libraries Government Documents Department
open access

A cryogenic system for TIBER II (Tokamak Ignition/Burn Experimental Reactor)

Description: Phase II of the Tokamak Ignition/Burn Experimental Reactor (TIBER II) study describes one option for a small, economical, next-generation tokamak (1,2). Because of its small size, minimum shielding is used between the plasma and the toroidal-field (TF) coils. Consequently, a large cryogenic system (approximately 70 kW at 4.5 K) capable of delivering forced-flow helium is required. This paper describes a cryogenic system that meets this requirement and includes TIBER-II requirements. 3 refs.
Date: October 7, 1987
Creator: Slack, D.S. & Kerns, J.A.
Partner: UNT Libraries Government Documents Department
open access

Responses to the low-level-radiation controversy

Description: Some data sets dealing with the hazards of low-level radiation are discussed. It is concluded that none of these reports, individually or collectively, changes appreciably or even significantly the evaluations of possible low-level radiation effects that have been made by several authoritative national and international groups. (ACR)
Date: October 7, 1981
Creator: Bond, V.P.
Partner: UNT Libraries Government Documents Department
open access

Plans for the CIT (Compact Ignition Tokamak) instrumentation and control system

Description: Extensive experience with previous fusion experiments (TFTR, MFTF-B and others) is driving the design of the Instrumentation and Control System (I and C) for the Compact Ignition Tokamak (CIT) to be built at Princeton. The new design will reuse much equipment from TFTR and will be subdivided into six major parts: machine control, machine data acquisition, plasma diagnostic instrument control and instrument data acquisition, the database, shot sequencing and safety interlocks. In a major departu… more
Date: October 7, 1987
Creator: Preckshot, G.G.
Partner: UNT Libraries Government Documents Department
open access

Optimized multi-modal-operation designs for ITER (International Thermonuclear Experimental Reactor)

Description: The tokamak nonlinear optimization systems code TETRA has been expanded to contain the option of examining machine designs capable of ''multi-modal'' operations. The conceptual International Thermonuclear Experimental Reactor (ITER) is an example of a ''bi-modal'' operating machine design in that it must be capable of both pulse-ignited and steady-state operations. This new version of TETRA allows for the optimization of a ''figure-of-merit'' which may involve several operating scenarios. We ob… more
Date: October 7, 1988
Creator: Blackfield, D. T.; Perkins, L. J.; Devoto, R. S.; Fenstermacher, M. E. & Ho, S. K.
Partner: UNT Libraries Government Documents Department
open access

Radiative effects of a CO/sub 2/ increase: results of a model comparison

Description: A comparison of infrared radiative transfer models is announced. The initial phase is underway, with other phases scheduled through 1984. The results of the ir model comparison will be included in the state-of-the-art report on climate modeling. Although the time scale for completion of the comparison is a few years, significant preliminary results have already been obtained. (PSB)
Date: October 7, 1982
Creator: Luther, F.M.
Partner: UNT Libraries Government Documents Department
open access

Energy flow in high speed perforation and cutting

Description: It is demonstrated that effects of long rod penetrators on targets can be modeled by introducing a high pressure (energy) column on the penetration path in place of the projectile. This energy can be obtained from the kinetic energy of the penetrator; the equations of state of the materials used and a Bernoulli penetration condition. The model is supported by detailed hydro calculations.
Date: October 7, 1980
Creator: van Thiel, M.
Partner: UNT Libraries Government Documents Department
open access

Interfacing solvent extraction in the recovery of pyrochemical residues at the Savannah River Plant

Description: The traditional feedstock for plutonium recovery at the Savannah River Plant (SRP) has been spent reactor fuel elements and irradiated targets. Feed sources have included both onsite reactors and a wide variety of domestic and foreign reactors. For the past few years, a growing and increasingly varied mix of unirradiated plutonium residues has been purified through SRP aqueous-based processes. Recently, plutonium residues generated in various chloride salt melts have become a significant offsit… more
Date: October 7, 1986
Creator: Gray, L.W. & Holcomb, H.P.
Partner: UNT Libraries Government Documents Department
open access

ARAC: A flexible real-time dose consequence assessment system

Description: Since its beginning, the Atmospheric Release Advisory Capability (ARAC), an emergency radiological dose assessment service of the US Government, has been called on to do consequence assessments for releases into the atmosphere of radionuclides and a variety of other substances. Some of the more noteworthy emergency responses have been for the Three Mile Island and Chernobyl nuclear power reactor accidents, and more recently, for a cloud of gases from a rail-car spill into the Sacramento river o… more
Date: October 7, 1993
Creator: Ellis, J. S. & Sullivan, T. J.
Partner: UNT Libraries Government Documents Department
open access

Photon Colliders

Description: A photon collider interaction region has the possibility of expanding the physics reach of a future TeV scale electron-positron collider. A survey of ongoing efforts to design the required lasers and optics to create a photon collider is presented in this paper.
Date: October 7, 2002
Creator: Gronberg, J.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen