166 Matching Results

Search Results

Results: 1 - 24 next
open access

Proceedings of the flat-plate solar array project research forum on photovoltaic metallization systems

Description: A Photovoltaic Metallization Research Forum, under the sponsorship of the Jet Propulsion Laboratory's Flat-Plate Solar Array Project and the US Department of Energy, was held March 16-18, 1983 at Pine Mountain, Georgia. The Forum consisted of five sessions, covering (1) the current status of metallization systems, (2) system design, (3) thick-film metallization, (4) advanced techniques and (5) future metallization challenges. Twenty-three papers were presented.
Date: November 15, 1983
Partner: UNT Libraries Government Documents Department
open access

Static and dynamic analyses on the MFTF-B vacuum vessel. Revision 1

Description: The Mirror Fusion Test Facility is a major magnetic fusion energy project at the Lawrence Livermore National Laboratory. An important component of this facility is the vacuum vessel, which forms the vacuum chamber. The vessel is supported on twenty-two pairs of legs that rest on reinforced concrete piers. In performing static and dynamic analyses on the vacuum vessel, we separately investigated the load distribution under gravity loads, pressure loads, electromagnetic loads, and thermal loads. … more
Date: January 15, 1984
Creator: Ng, D.S.
Partner: UNT Libraries Government Documents Department
open access

Heavy leptons at the SSC

Description: It is argued that detection of heavy leptons at the Superconducting Super Collider seems to be very difficult but perhaps not impossible. The feasibility is shown to depend critically upon the ability to identify events with W's decaying hadronically and missing transverse momentum. (LEW)
Date: December 15, 1987
Creator: Anderson, G. & Hinchliffe, I.
Partner: UNT Libraries Government Documents Department
open access

Metallic coating of microspheres

Description: Extremely smooth, uniform metal coatings of micrometer thicknesses on microscopic glass spheres (microspheres) are often needed as targets for inertial confinement fusion (ICF) experiments. The first part of this paper reviews those methods used successfully to provide metal coated microspheres for ICF targets, including magnetron sputtering, electro- and electroless plating, and chemical vapor pyrolysis. The second part of this paper discusses some of the critical aspects of magnetron sputter … more
Date: August 15, 1980
Creator: Meyer, S.F.
Partner: UNT Libraries Government Documents Department
open access

Three-dimensional linear analysis of fluid-structure interaction effects in the Mark I BWR pressure suppression torus

Description: Most analytical and experimental approaches to the evaluation of fluid-structure interaction (FSI) effects in the General Electric Mark I BWR pressure suppression system treat the torus shell as rigid when the shell in real systems is flexible. This report describes linear three-dimensional finite-element analyses of one torus bay that investigated the qualitative effect of torus wall flexibility on hydrodynamic loads induced by a nominal safety relief valve (SRV) discharge. The results of thes… more
Date: January 15, 1980
Creator: Holman, G.S.; McCauley, E.W. & Lu, S.C.
Partner: UNT Libraries Government Documents Department
open access

Occurrence and use of complex resonances (poles in scattering and radiation problems)

Description: In a wide variety of physics problems, especially those which involve wave phenomena such as in electromagnetics and acoustics, a behavior results that can be described by systems of linear (partial) differential equations. Solutions to such problems often can be expressed simply in the form of an exponential series. Some specific background material for this approach is discussed, and a variety of example applications is summarized. (WHK)
Date: December 15, 1981
Creator: Miller, E. K.
Partner: UNT Libraries Government Documents Department
open access

Tandem mirror fusion fission hybrid studies

Description: Initial Tandem Mirror Hybrid Study predicts the ability to produce large amounts of fissile fuel (2 to 7 tonnes per year U233 from a 4000 MW plant) at a cost that adds less than 25% to the cost of power from an LWR.
Date: February 15, 1980
Creator: Lee, J. D.
Partner: UNT Libraries Government Documents Department
open access

Incorporation of high-level wastes in SYNROC: results from recent process-engineering studies at Lawrence Livermore National Laboratory

Description: In this paper, highlights from recent engineering research and development, in particular, results from fluidized bed calcination studies of SYNROC slurry are summarized. A schematic diagram of the envisioned SYNROC process (at this stage of development) is also presented. It shows the use of a fluidized bed calciner to prepare SYNROC powder that is then fed to a storage hopper. Bellows-type canisters are filled, evacuated, sealed and preheated. The preheated canisters are loaded into a hot iso… more
Date: April 15, 1982
Creator: Campbell, J. H.; Hoenig, C. L.; Ackerman, F. J.; Peters, P. E. & Grens, J. Z.
Partner: UNT Libraries Government Documents Department
open access

Immobilization of high-level defense wastes in SYNROC-D: recent research and development results on process scale-up

Description: SYNROC is a titanate-based ceramic waste form being developed to immobilize high-level nuclear reactor wastes. SYNROC-D is a unique variation of SYNROC designed to contain high-level defense wastes, particularly those in storage at the Savannah River Plant (SRP). We review recent research and development on SYNROC-D processing options and report on work in progress on various unit operations. The overall immobilization process can be divided into three general parts: (1) slurry preparation (for… more
Date: March 15, 1982
Creator: Campbell, J. H.; Rozsa, R. B. & Hoenig, C. L.
Partner: UNT Libraries Government Documents Department
open access

Application of Monte Carlo codes to neutron dosimetry

Description: In neutron dosimetry, calculations enable one to predict the response of a proposed dosimeter before effort is expended to design and fabricate the neutron instrument or dosimeter. The nature of these calculations requires the use of computer programs that implement mathematical models representing the transport of radiation through attenuating media. Numerical, and in some cases analytical, solutions of these models can be obtained by one of several calculational techniques. All of these techn… more
Date: June 15, 1982
Creator: Prevo, C.T.
Partner: UNT Libraries Government Documents Department
open access

ECRH and ICRH in the TMX-U Tandem Mirror

Description: In the Tandem Mirror Experiment Upgrade (TMX-U), the formation of a thermal barrier and the potential plugging of ion end loss were achieved at central-cell densities up to 2 x 10/sup 12/ cm/sup -3/. The presence of a thermal barrier was confirmed by direct measurement, and ion axial-confinement times in the range 50 to 100 ms were measured. The ECRH in the end cells (a) initiates plasma startup, (b) generates hot, mirror-confined electrons to form thermal barriers, and (c) creates the plugging… more
Date: March 15, 1984
Creator: Stallard, B. W.; Cummins, W. F.; Molvik, A. W.; Poulsen, P.; Simonen, T. C.; Falabella, S. et al.
Partner: UNT Libraries Government Documents Department
open access

Effects of torus wall flexibility on forces in the Mark I BWR pressure suppression system under SRV T-quencher loading

Description: This report describes a series of extended analyses requested by the US Nuclear Regulatory Commission to provide qualified understanding of possible fluid/structure interaction (FSI) effects for SRV teequencher test results. Three input pulses with total impulses varying by up to a factor of five are applied to two-dimensional finite-element models of the Mark I torus with shell diameter-to-thickness ratios of 0, 300, and 600. The results of these analyses support earlier conclusions that incre… more
Date: January 15, 1980
Creator: Holman, G.S. & Lu, S.C.
Partner: UNT Libraries Government Documents Department
open access

Broad-band soft x-ray diagnostic instruments at the LLNL Novette laser facility

Description: Complementary broad-band instruments have been developed to measure time dependent, absolute soft x-ray spectra at the Lawrence Livermore National Laboratory (LLNL) Nd glass laser irradiation facilities. Absolute flux measurements of x rays emitted from laser-produced plasmas are important for understanding laser absorption and energy transport. We will describe two new 10-channel XRD systems that have been installed at the LLNL Novette facility for use in the 0.15- to 1.5-keV range. Since XRD … more
Date: September 15, 1983
Creator: Tirsell, K.G.; Lee, P.H.Y.; Nilson, D.G. & Medecki, H.
Partner: UNT Libraries Government Documents Department
open access

Evaluating Alternative Responses to Safeguards Alarms

Description: This paper describes a quantitative approach to help evaluate and respond to safeguards alarms. These alarms may be generated internally by a facility's safeguards systems or externally by individuals claiming to have stolen special nuclear material (SNM). This approach can be used to identify the most likely cause of an alarm - theft, hoax, or error - and to evaluate alternative responses to alarms. Possible responses include conducting investigations, initiating measures to recover stolen SNM… more
Date: April 15, 1982
Creator: Al-Ayat, R. A.; Judd, B. R. & McCord, R. K.
Partner: UNT Libraries Government Documents Department
open access

Current status of fast-neutron-capture calculations

Description: This work is primarily concerned with the calculation of neutron capture cross sections and capture gamma-ray spectra, in the framework of the Hauser-Feshbach statistical model and for neutrons from the resonance region up to several MeV. An argument is made that, for applied purposes such as constructing evaluated cross-section libraries, nonstatistical capture mechanisms may be completely neglected at low energies and adequately approximated at high energies in a simple way. The use of gamma-… more
Date: April 15, 1982
Creator: Gardner, D. G.
Partner: UNT Libraries Government Documents Department
open access

LLL calibration and standards facility

Description: The capabilities of Lawrence Livermore Laboratory's Calibration and Standards Facility are delineated. The facility's ability to provide radiation fields and measurements for a variety of radiation safety applications and the available radiation measurement equipment are described. The need for national laboratory calibration labs to maintain traceability to a national standard are discussed as well as the areas where improved standards and standardization techniques are needed.
Date: April 15, 1980
Creator: Campbell, G.W. & Elliott, J.H.
Partner: UNT Libraries Government Documents Department
open access

Detailed photonuclear cross-section calculations and astrophysical applications

Description: We have investigated the role of an isomeric state and its coupling to the ground state (g.s.) via photons and neutron inelastic scattering in a stellar environment by making detailed photonuclear and neutron cross-section calculations for /sup 176/Lu and /sup 210/Bi. In the case of /sup 176/Lu, the g.s. would function as an excellent galactic slow- (s-) process chronometer were it not for the 3.7-h isomer at 123 keV. Our calculations predicted much larger photon cross sections for production o… more
Date: June 15, 1989
Creator: Gardner, D. G.; Gardner, M. A. & Hoff, R. W.
Partner: UNT Libraries Government Documents Department
open access

Liquid nitrogen cooling considerations of the compact ignition tokamak

Description: An analytical procedure was developed to estimate the cooldown time between pulses of the Compact Ignition Tokamak (CIT) utilizing liquid nitrogen. Fairly good agreement was obtained between the analysis results and those measured in the early fusion experimental devices. The cooldown time between pulses in the CIT is controlled by the energy disposition in the inner leg of the TF coil. A cooldown time of less than one hour is feasible for the CIT if fins are used in the cooling channels. An R … more
Date: June 15, 1986
Creator: Dabiri, A. E.
Partner: UNT Libraries Government Documents Department
open access

Production of eta mesons in e/sup +/e/sup -/ annihilations at. sqrt. s = 29 GeV

Description: Data from e/sup +/e/sup -/ annihilations at 29 GeV have been used to measure the production and fragmentation of eta mesons. The signal is observed in the eta ..-->.. ..gamma gamma.. decay channel. The fragmentation function for p/sub eta/ > 1.5 GeV/c agrees well with the shapes predicted by both the Lund and Webber models. However, the mean multiplicity is measured to be < n/sub eta/ > = 0.37 +- 0.08 eta mesons per hadronic annihilation event, which is significantly lower than the values predi… more
Date: June 15, 1987
Creator: Abachi, S.; Akerlof, C.; Baringer, P.; Blockus, D.; Brabson, B.; Brom, J.M. et al.
Partner: UNT Libraries Government Documents Department
open access

Improved Approach to Characterizing and Presenting Streak Camera Performance

Description: The performance of a streak camera recording system is strongly linked to the technique used to amplify, detect and quantify the streaked image. At the Lawrence Livermore National Laboratory (LLNL) streak camera images have been recorded both on film and by fiber-optically coupling to charge-coupled devices (CCD's). During the development of a new process for recording these images (lens coupling the image onto a cooled CCD) the definitions of important performance characteristics such as resol… more
Date: July 15, 1985
Creator: Wiedwald, J. D. & Jones, B. A.
Partner: UNT Libraries Government Documents Department
open access

Glovebox enclosed dc plasma source for the determination of metals in plutonium

Description: The direct current plasma source of a Beckman Spectraspan IIIB emission spectrometer was enclosed in a glovebox at Lawrence Livermore National Laboratory in December 1982. Since that time, the system has been used for the routine determination of alloy and impurity metals in plutonium. This paper presents the systematic steps involved in developing the glovebox and gives information regarding performance of the plasma in the glovebox and the effectiveness of containment of plutonium. 8 refs., 9… more
Date: January 15, 1986
Creator: Morris, W.F.
Partner: UNT Libraries Government Documents Department
open access

Status report on the Los Alamos National Laboratory Ion Beam Facility

Description: The Ion Beam Facility operated for 6000 machine hours last year, ranging in energy from 300 Kev to 24 Mev. Improvements include cryopumps replacing diffusion pumps, a rebuilding of the tandem chopper electronics and the vertical's corona charging system. Methane molecules were successfully accelerated by the vertical in quantities of hundreds of nanoamperes. Two replacement magnet power supplies on the tandem and a completely new capacitor shell regulator on the vertical are soon to be installe… more
Date: November 15, 1985
Creator: Woods, R.; Tesmer, J.; Rowton, L.; Ingalls, W.; Chaparro, G.; Goosney, G. et al.
Partner: UNT Libraries Government Documents Department
open access

Magnetic shielding for the long-pulse, pure-beam source neutralizers on the MFTF-B

Description: Present ion sources produce deuterium ions plus small amounts of impurity ions including oxygen. The oxygen current is readily trapped by the Mirror Fusion Test Facility-B (MFTF-B) plasma and represents a severe energy loss mechanism. A pure-beam source-neutralizer has been designed by LLNL for the MFTF-B. This concept uses momentum separation by closely coupling an electromagnet to the source to purify the beam. This design requires a low pressure in the neutralizer, implying a long length and… more
Date: November 15, 1985
Creator: Kerns, J.; Stone, R.; Fabyan, F. & Martin, D.
Partner: UNT Libraries Government Documents Department
open access

Application of structural-mechanics methods to the design of large tandem-mirror fusion devices (MFTF-B). Revision 1

Description: The Mirror Fusion Test Facility (MFTF-B) at Lawrence Livermore National Laboratory requires state-of-the-art structural-mechanics methods to deal with access constraints for plasma heating and diagnostics, alignment requirements, and load complexity and variety. Large interactive structures required an integrated analytical approach to achieve a reasonable level of overall system optimization. The Tandem Magnet Generator (TMG) creates a magnet configuration for the EFFI calculation of electroma… more
Date: August 15, 1985
Creator: Karpenko, V.N. & Ng, D.S.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen