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Approach to decision modeling for an ignition test reactor (open access)

Approach to decision modeling for an ignition test reactor

A comparison matrix decision model is applied to candidates for a D-T ignition tokamak (TNS), including assessment of semi-quantifiable or judgemental factors as well as quantitative ones. The results show that TNS is mission-sensitive with a choice implied between near-term achievability and reactor technology.
Date: September 30, 1977
Creator: Howland, H.R. & Varljen, T.C.
System: The UNT Digital Library
High resolution difference schemes for compressible gas dynamics (open access)

High resolution difference schemes for compressible gas dynamics

The advantages and disadvantages of four new high-resolution difference schemes, namely the von Neumann-Richtmyer, Godunovs, MUSCL and Glimms, for mathematically representing physical conditions in compressible gas flows are compared. (LCL)
Date: July 30, 1980
Creator: Woodward, P. & Colella, P.
System: The UNT Digital Library
Future engineering needs of mirror fusion reactors (open access)

Future engineering needs of mirror fusion reactors

Fusion research has matured during the last decade and significant insight into the future program needs has emerged. While some will properly note that the crystal ball is cloudy, it is equally important to note that the shape and outline of our course is discernable. In this short summary paper, I will draw upon the National Mirror Program Plan for mirror projects and on available design studies of these projects to put the specific needs of the mirror program in perspective.
Date: July 30, 1982
Creator: Thomassen, K.I.
System: The UNT Digital Library
Free-electron laser generation of VUV and x-ray radiation using a conditioned beam and ion-channel focusing (open access)

Free-electron laser generation of VUV and x-ray radiation using a conditioned beam and ion-channel focusing

The use of ion-focusing and a conditioned beam greatly enhances FEL gain in the VUV and Soft X-Ray range. The equations governing FEL amplification are derived and results of a linear analysis are noted. Numerical results, including 3D effects and having an order of magnitude improvement in gain, are presented for a 30 {Angstrom} example. 3 refs., 2 figs., 1 tab.
Date: August 30, 1991
Creator: Yu, Li-Hua (Brookhaven National Lab., Upton, NY (United States)); Sessler, A. & Whittum, D.H. (Lawrence Berkeley Lab., CA (United States))
System: The UNT Digital Library
Double-mode pulsation (open access)

Double-mode pulsation

Double mode pulsation is a very pervasive phenomenon in stars all over the Hertzsprung-Russell diagram. In order of increasing radius, examples are: ZZ Ceti stars, the sun, the delta Scuti stars, RR Lyrae variables, the ..beta.. Cephei variables and those related to them, Cepheids, and maybe even the Mira stars. These many modes have been interpreted as both radial and nonradial modes, but in many cases the actual mode has not been clearly identified. Yellow giants seem to be the most simple pulsators with a large majority of the RR Lyrae variables and Cepheids showing only one pulsation period. We limit this review to those very few cases for classical Cepheids and RR Lyrae variables which display two modes. For these we know many facts about these stars, but the actual cause of the pulsation in two modes simultaneously remains unknown.
Date: July 30, 1982
Creator: Cox, A. N.
System: The UNT Digital Library
Engineering design solutions of flux swing with structural requirements for ohmic heating solenoids (open access)

Engineering design solutions of flux swing with structural requirements for ohmic heating solenoids

Here a more detailed publication is summarized which presents analytical methods with solutions that describe the structural behavior of ohmic heating solenoids to achieve a better understanding of the relationships between the functional variables that can provide the basis for recommended design improvements. The solutions relate the requirements imposed by structural integrity to the need for producing sufficient flux swing to initiate a plasma current in the tokamak fusion machine. A method is provided to perform a detailed structural analysis of every conducting turn in the radial build of the solenoid, and computer programmed listings for the closed form solutions are made available as part of the reference document. Distinction is made in deriving separate models for the regions of the solenoid where turn-to-turn radial contact is maintained with radial compression or with a bond in the presence of radial tension, and also where there is turn-to-turn radial separation due to the absence or the loss of bonding in the presence of would be radial tension. The derivations follow the theory of elasticity for a body possessing cylindrical anisotropy where the material properties are different in the radial and tangential directions. The formulations are made practical by presenting the methods …
Date: September 30, 1977
Creator: Smith, R. A.
System: The UNT Digital Library
Determination of performance criteria for high-level solidified nuclear waste from the commercial nuclear fuel cycle: a probabilistic safety analysis (open access)

Determination of performance criteria for high-level solidified nuclear waste from the commercial nuclear fuel cycle: a probabilistic safety analysis

To minimize the radiological risk from the operation of a waste management system for the safe disposal of high-level waste, performance characteristics of the solidified waste form must be specified. The minimum waste form characteristics that must be specified are the radionuclide volatilization fraction, airborne particulate dispersion fraction, and the aqueous dissolution characteristics. The results indicate that the pre-emplacement environs are more limiting in establishing the waste form performance criteria than the post-emplacement environs. The actual values of expected risk are sensitive to modeling assumptions and data base uncertainties. The transportation step appears to be the most limiting in determining the required performance characteristics.
Date: March 30, 1978
Creator: Heckman, R.A.
System: The UNT Digital Library
CSU solar house I solar collector (open access)

CSU solar house I solar collector

None
Date: June 30, 1975
Creator: Ward, D.S.
System: The UNT Digital Library
Thermal design and analysis of superconductors for the toroidal field coils of TNS. [NbTi] (open access)

Thermal design and analysis of superconductors for the toroidal field coils of TNS. [NbTi]

The toroidal field coils in two of the four TNS field coil design options are superconducting. NbTi superconductors are used in the low field design option and Nb/sub 3/Sn superconductors are used in the high field design option. The preliminary conceptual design parameters of the coils and the superconductors have been developed. The selected coil shape is the pure tension D-configuration. The superconductors are the multifilamentary, cabled design and are cooled by forced flow supercritical helium. Thermal stability analyses were performed for the superconductors. The cryogenic recovery capability of the NbTi superconductors is more than 10/sup 5/ J/m/sup 3/ of conductor plus helium volume and that of the Nb/sub 3/Sn is more than 3 x 10/sup 5/ j/m/sup 3/.
Date: September 30, 1977
Creator: Lee, A. Y.
System: The UNT Digital Library
Tritium related safety considerations for mirror upgrades (open access)

Tritium related safety considerations for mirror upgrades

One of the primary objectives of the MFTF-B upgrades is to demonstrate the technology of tritium breeding in a reactor-like configuration. This requires use and processing of tritium, involving an inventory of several hundred grams at the plant. This paper reviews the results of a preliminary assessment of the radiation hazard associated with the handling of tritium. The radiation dose consequences due to tritium release from normal operation and due to postulated accidents on plant personnel and the public were assessed. Maximum credible (probability < 10/sup -3/, but > 10/sup -7//yr) accidental releases were estimated to be 10 gm in the reactor building and 100 gm in the tritium-processing building. Higher probability (> 10/sup -3//yr) accidents or component failures would result in much smaller releases. In the reactor building, the most severe accident would result from the rupture of a plasma exhaust duct from the end cell or the tritium feed pipe to the neutral beam injector, accompanied by a fire. In the tritium processing building, the most severe accident would be the rupture of the Isotope Separation System (ISS) distillation columns and vacuum jackets accompanied by a fire.
Date: November 30, 1983
Creator: Ghose, S.K.
System: The UNT Digital Library
Spectra of matrix isolated metal atoms and clusters. [In rare gases] (open access)

Spectra of matrix isolated metal atoms and clusters. [In rare gases]

The matrix isolation spectra of all of the 40 presently known atomic metal species show strong matrix effects. The transition energies are increased, and the bands are broad and exhibit splitting of sublevels which are degenerate in the gas phase. Several models have been proposed for splitting of levels, but basic effects are not yet understood, and spectra cannot be predicted, yet it is possible to correlate gas phase and matrix in many of the systems. Selective production of diatomics and clusters via thermal and optical annealing of atomic species can be monitored by optical spectra, but yields spectroscopically complex systems which, however, especially in the case of transition metals, can be used as precursors in novel chemical reactions. A combination of absorption, emission, ir, Raman, ESR, and other methods is now quickly yielding data which will help correlate the increasing wealth of existing data. 55 references, 6 figures.
Date: September 30, 1977
Creator: Meyer, B.
System: The UNT Digital Library
NOVA laser facility for inertial confinement fusion (open access)

NOVA laser facility for inertial confinement fusion

The NOVA laser consists of ten beams, capable of concentrating 100 to 150 kJ of energy (in 3 ns) and 100 to 150 TW of power (in 100 ps) on experimental targets by 1985. NOVA will also be capable of frequency converting the fundamental laser wavelength (1.05 ..mu..m) to its second (0.525 ..mu..m) or third (0.35 ..mu..m) harmonic. This additional capability (80 to 120 kJ at 0.525 ..mu..m, 40 to 70 kJ at 0.35 ..mu..m) was approved by the US Department of Energy (DOE) in April 1982. These shorter wavelengths are much more favorable for ICF target physics. Current construction status of the NOVA facility, intended for completion in the autumn of 1984, will be presented.
Date: November 30, 1983
Creator: Simmons, W.W.
System: The UNT Digital Library
Division of labor among the alpha-6 beta-4 integrin, beta-1 integrins and an E3 laminin receptor to signal morphogenesis and beta-casein expression in mammary epithelial cells (open access)

Division of labor among the alpha-6 beta-4 integrin, beta-1 integrins and an E3 laminin receptor to signal morphogenesis and beta-casein expression in mammary epithelial cells

None
Date: June 30, 1999
Creator: Muschler, J.; Lochter, A.; Roskelley, C. D.; Yurchenco, P. & Bissell, M. J.
System: The UNT Digital Library
Cancer risks and neutron RBE's from Hiroshima and Nagasaki (open access)

Cancer risks and neutron RBE's from Hiroshima and Nagasaki

The new radiation dose estimates for Hiroshima and Nagasaki are here combined with epidemiologic data from the A-bomb survivors and examined radiobiologically for compatability with other human and experimental data. The new doses show certain improvements over the original T65 doses. However, they suggest for chronic granulocytic leukemia, total malignancies, and chromosome aberrations, at neutron doses of 1 rad, RBEs in excess of 100, higher than expected from other findings. This and other indications suggest that either there are unrecognized systematic problems with the various radiobiological data, or the new doses are deficient in neutrons for Hiroshima, by a factor of about five. If in fact there were actually some 5-fold more dose from neutrons at Hiroshima than estimated by the new calculations, the RBEs would agree well with laboratory results, and other inconsistencies would largely disappear. Cancer risks are estimated for neutrons from the new doses and are compared with those estimated from radiobiologically reconciled doses (the new doses adjusted by adding approximately 5-fold more neutrons). The latter estimates appear more reasonable. For low-LET radiation, cancer risk estimates are altered very little by the new dose estimates for Nagasaki.
Date: April 30, 1982
Creator: Dobson, R.L. & Straume, T.
System: The UNT Digital Library
Nuclear criticality information system (open access)

Nuclear criticality information system

The nuclear criticality safety program at LLNL began in the 1950's with a critical measurements program which produced benchmark data until the late 1960's. This same time period saw the rapid development of computer technology useful for both computer modeling of fissile systems and for computer-aided management and display of the computational benchmark data. Database management grew in importance as the amount of information increased and as experimental programs were terminated. Within the criticality safety program at LLNL we began at that time to develop a computer library of benchmark data for validation of computer codes and cross sections. As part of this effort, we prepared a computer-based bibliography of criticality measurements on relatively simple systems. However, it is only now that some of these computer-based resources can be made available to the nuclear criticality safety community at large. This technology transfer is being accomplished by the DOE Technology Information System (TIS), a dedicated, advanced information system. The NCIS database is described.
Date: November 30, 1981
Creator: Koponen, B. L. & Hampel, V. E.
System: The UNT Digital Library
Investigation of the cryogenic mechanical properties of low thermal-expansion superalloys (open access)

Investigation of the cryogenic mechanical properties of low thermal-expansion superalloys

Four Fe-based superalloys, JBK-75, Incoloy 903, Incoloy 905, and Incoloy 909 were evaluated as tube materials for ICCS Nb/sub 3/Sn superconductors. Evaluation consisted of 4-K tensile and elastic-plastic fracture-toughness testing, and a microstructural characterization of unwelded and autogenously gas-tungsten-arc welded sheet given a simulated postweld processing treatment of 15% cold reduction by rolling followed by a Nb/sub 3/Sn-reaction heat treatment of 96 hours at 700/sup 0/C plus 48 hours at 730/sup 0/C. Results indicate that JBK-75 and Incoloy 903 showed satisfactory combinations of strength and toughness for ICCS tube use requiring long Nb/sub 3/Sn-reaction heat treatments. Incoloy 905 welds and 909 showed unacceptable fracture toughness. Results are discussed in terms of microstructural changes caused by the extended Nb/sub 3/Sn-reaction heat treatment.
Date: July 30, 1985
Creator: Summers, L.T. & Dalder, E.N.C.
System: The UNT Digital Library
Stable propagation of an electron beam in gas (open access)

Stable propagation of an electron beam in gas

Conditions for the stable propagation of a pinched electron beam in low pressure gas (p approximately 0.1 to 100 torr) are described. The observed window of good propagation around p approximately 2 torr air is interpreted as the quenching of the two-stream mode by sufficiently high plasma density and collision frequency, and the simultaneous suppression of the resistive hose mode by sufficiently rapid generation of electrical conductivity from breakdown ionization.
Date: September 30, 1977
Creator: Lee, E. P.; Chambers, F. W.; Lodestro, L. L. & Yu, S. S.
System: The UNT Digital Library
Compact Fusion Advanced Rankine (CFARII) power cycle---Operating regimes (open access)

Compact Fusion Advanced Rankine (CFARII) power cycle---Operating regimes

Performance (cost/kWe and efficiency) of generic Compact Fusion Advanced Rankine (CFARII) power conversion is investigated for various working fluids, operating temperatures and pressures, and thermal power levels. A general conclusion is that good CFARII performance is found for a remarkably broad range of materials, temperatures, pressures and power levels, which gives considerable flexibility to future design studies which may apply CFARII energy conversion to specific fusion energy sources such as ICF, MICF, and Mini-PACER. 5 refs, 7 figs., 2 tabs.
Date: September 30, 1991
Creator: Logan, B. G.
System: The UNT Digital Library
Poloidal field coil design for a fusion--fission breeder reactor (open access)

Poloidal field coil design for a fusion--fission breeder reactor

The magnetic, structural, and thermal design of superconducting poloidal field coils for a tokamak fusion-fission breeder reactor are described. The design requirements and considerations, with the resulting parameters, are presented.
Date: September 30, 1977
Creator: Howland, H. R.; Kelly, J .L. & Chi, J. W. H.
System: The UNT Digital Library
An automated tool for evaluating compliance and providing assistance with building energy standards during design (open access)

An automated tool for evaluating compliance and providing assistance with building energy standards during design

In an effort to encourage the maximum cost-effective level of energy efficiency in new building design, energy-efficiency standards have become more location-specific and performance-based. As a result, standards often provide more than one path for ensuring and demonstrating that a design complies, but at the cost of increased complexity. In addition, the burden of remedying a noncompliant design rests on the designers' knowledge and experience, with only general guidance provided by the standards. As part of efforts in the US Department of Energy's (DOE's) Advanced Energy Design and Operation Technologies (AEDOT) project, a team at DOE's Pacific Northwest Laboratory is developing a computer program known as the Energy Standards Intelligent Design Tool (ES-IDT). The ES-IDT is one component of a prototype computer-based building design environment. It performs automatic compliance checking for parts of ASHRAE/IES Standard 90.1-1989 and provides designers assistance in bringing noncomplying designs into compliance. This paper describes the ES-IDT, the functions it provides, and how it is integrated into the design process via the AEDOT prototype building design environment. 9 refs.
Date: April 30, 1992
Creator: Quadrel, R.W.; Brambley, M.R. & Stratton, R.C.
System: The UNT Digital Library
Impurity and gas throughput control for TNS (open access)

Impurity and gas throughput control for TNS

A model of the interaction between an ignited plasma and a wall is utilized to study the impact of impurities and recycled fuel ions and helium ash on the burn time of the plasma. The model indicates that the impurity concentration, n/sub im/, grows exponentially toward a maximum value determined by the confinement time for impurities, tau/sub im/, the sputtering coefficient, S/sub i/, and the isolation coefficient, ..cap alpha... The time for n/sub im/ to reach a critical value and quench the plasma was determined for representative impurities, C, Mo, W, Fe, under various conditions of plasma temperature. Methods for extending the burn time by minimizing the effective sputtering coefficient of the wall and increasing the isolation of the plasma from the wall are reviewed. The carbides, B/sub 4/C and SiC, are found to have encouraging sputtering properties but their thermal, chemical and mechanical properties need to be evaluated before they can be recommended for use as first walls. The magnetic divertor is the preferred isolation scheme. Because the divertor carries impurities and leaked fuel and helium ions to a burial chamber, required pumping speeds are found to be very high for TNS plasmas and supplemental particle trapping systems must …
Date: September 30, 1977
Creator: Sucov, E. W.
System: The UNT Digital Library
Mirror Fusion Test Facility: an intermediate device to a mirror fusion reactor (open access)

Mirror Fusion Test Facility: an intermediate device to a mirror fusion reactor

The Mirror Fusion Test Facility (MFTF-B) now under construction at Lawrence Livermore National Laboratory represents more than an order-of-magnitude step from earlier magnetic-mirror experiments toward a future mirror fusion reactor. In fact, when the device begins operating in 1986, the Lawson criteria of ntau = 10/sup 14/ cm/sup -3/.s will almost be achieved for D-T equivalent operation, thus signifying scientific breakeven. Major steps have been taken to develop MFTF-B technologies for tandem mirrors. Steady-state, high-field, superconducting magnets at reactor-revelant scales are used in the machine. The 30-s beam pulses, ECRH, and ICRH will also introduce steady-state technologies in those systems.
Date: March 30, 1983
Creator: Karpenko, V.N.
System: The UNT Digital Library
Optical pumping of hot phonons in GaAs (open access)

Optical pumping of hot phonons in GaAs

Optical pumping of hot LO phonons in GaAs has been studied as a function of the excitation photon frequency. The experimental results are in good agreement with a model calculation which includes both inter- and intra-valley electron-phonon scatterings. The GAMMA-L and GAMMA-X intervalley electron-phonon interactions in GaAs have been estimated.
Date: June 30, 1982
Creator: Collins, C.L. & Yu, P.Y.
System: The UNT Digital Library
Duct Systems in Large Commercial Buildings: Physical Characterization, Air Leakage, and Heat Conduction Gains (open access)

Duct Systems in Large Commercial Buildings: Physical Characterization, Air Leakage, and Heat Conduction Gains

None
Date: March 30, 1999
Creator: Fisk, William J.; Delp, Woody W.; Diamond, Rick C.; Dickerhoff, Darryl J.; Levinson, Ronnen M.; Modera, Mark P. et al.
System: The UNT Digital Library