101 Matching Results

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Structure functions: Their status and implications (open access)

Structure functions: Their status and implications

I discuss the current status of structure functions. Attention is given to the uncertainties in them and the implications of these uncertainties for experimental predictions. I indicate which experiments are capable of removing these uncertainties. 17 refs., 17 figs., 1 tab.
Date: September 29, 1988
Creator: Hinchliffe, I.
System: The UNT Digital Library
Variable temperature effects on release rates of readily soluble nuclides (open access)

Variable temperature effects on release rates of readily soluble nuclides

In this paper we study the effect of temperature on the release rate of readily soluble nuclides, as affected by a time-temperature dependent diffusion coefficient. In this analysis ground water fills the voids in the waste package at t = 0 and one percent of the inventories of cesium and iodine are immediately dissolved into the void water. Mass transfer resistance of partly failed container and cladding is conservatively neglected. The nuclides move through the void space into the surrounding rock under a concentration gradient. We use an analytic solution to compute the nuclide concentration in the gap or void, and the mass flux rate into the porous rock. 8 refs., 4 figs.
Date: September 1, 1988
Creator: Kim, C. L.; Light, W. B.; Lee, W. W. L.; Chambre, P. L.; Pigford, T. H. (Korea Advanced Energy Research Inst., Daeduk (Republic of Korea) & Lawrence Berkeley Lab, C A (USA))
System: The UNT Digital Library
New topological invariants for non-abelian antisymmetric tensor fields from extended BRS algebra (open access)

New topological invariants for non-abelian antisymmetric tensor fields from extended BRS algebra

Extended non-linear BRS and Gauge transformations containing Lie algebra cocycles, and acting on non-abelian antisymmetric tensor fields are constructed in the context of free differential algebras. New topological invariants are given in this framework. 6 refs.
Date: September 1, 1988
Creator: Boukraa, S.; Maillet, J.M. & Nijhoff, F.
System: The UNT Digital Library
Design, placement, and sampling of groundwater monitoring wells for the management of hazardous waste disposal facilities (open access)

Design, placement, and sampling of groundwater monitoring wells for the management of hazardous waste disposal facilities

Groundwater monitoring is an important technical requirement in managing hazardous waste disposal facilities. The purpose of monitoring is to assess whether and how a disposal facility is affecting the underlying groundwater system. This paper focuses on the regulatory and technical aspects of the design, placement, and sampling of groundwater monitoring wells for hazardous waste disposal facilities. Such facilities include surface impoundments, landfills, waste piles, and land treatment facilities. 8 refs., 4 figs.
Date: September 30, 1988
Creator: Tsai, S.Y.
System: The UNT Digital Library
Partitioning of hydrogen in the vanadium-lithium-hydrogen system at elevated temperatures (open access)

Partitioning of hydrogen in the vanadium-lithium-hydrogen system at elevated temperatures

Equilibrium concentrations of hydrogen in vanadium-base alloys exposed to flowing lithium at temperatures from 350 to 550/degree/C in a forced-circulation loop were measured by residual gas analysis and the vacuum fusion method. Residual gas analysis and removal of material from the surface allowed a determination of the spatial hydrogen distribution in the alloys. These experimental results were compared with calculated thermodynamic distribution coefficients for hydrogen in the vanadium/lithium system. Small amounts of other solutes in the molten lithium and in the alloys affected the solubility, diffusivity, and resultant distribution of hydrogen. Thermodynamic calculations demonstrated the importance of major alloying elements to the partitioning of hydrogen. 12 refs., 5 figs., 2 tabs.
Date: September 1, 1988
Creator: Hull, A. B.; Chopra, O. K.; Loomis, B. A. & Smith, D. L.
System: The UNT Digital Library
Preliminary report confined tension testing of 900-24 (open access)

Preliminary report confined tension testing of 900-24

A specially designed confining pressure vessel is described that allows tensile samples to be tested under a superimposed confining hydrostatic pressure. Tests on samples of well characterized materials such as aluminum were used to verify the operation of the system, calibration of the internal load cell, and data reduction methods. The results of a series of exploratory tests done on the inert material 900-24 are described. 4 refs., 17 figs., 2 tabs.
Date: September 10, 1988
Creator: Harlow, R.A. & Browning, R.V.
System: The UNT Digital Library
Induction linac drivers for heavy ion fusion (open access)

Induction linac drivers for heavy ion fusion

The Heavy Ion Fusion Accelerator Research (HIFAR) program of the USDOE has for several years concentrated on developing linear induction accelerators as Inertial Fusion (IF) drivers. This accelerator technology is suitable for the IF application because it is readily capable of accelerating short, intense pulses of charged particles with good electrical efficiency. The principal technical difficulty is in injecting and transporting the intense pulses while maintaining the necessary beam quality. The approach used has been to design a system of multiple beams so that not all of the charge has to be confined in a single beam line. The beams are finally brought together in a common focus at the target. This paper will briefly present the status and future plans of the program, and will also briefly review systems study results for HIF. 2 refs., 5 figs.
Date: September 1, 1988
Creator: Herrmannsfeldt, W.B. & Keefe, D.
System: The UNT Digital Library
A Compact X-Ray Free Electron Laser (open access)

A Compact X-Ray Free Electron Laser

We present a design concept and simulation of the performance of a compact x-ray, free electron laser driven by ultra-high gradient rf-linacs. The accelerator design is based on recent advances in high gradient technology by a LLNL/SLAC/LBL collaboration and on the development of bright, high current electron sources by BNL and LANL. The GeV electron beams generated with such accelerators can be concerted to soft x-rays in the range from 2--10 nm by passage through short period, high fields strength wigglers as are being designed at Rocketdyne. Linear light sources of this type can produce trains of picosecond (or shorter) pulses of extremely high spectral brilliance suitable for flash holography of biological specimens in vivo and for studies of fast chemical reactions. 12 refs., 8 figs., 4 tabs.
Date: September 9, 1988
Creator: Barletta, W.; Attac, M.; Cline, D.B.; Kolonko, J.; Wang, X.; Bhowmik, A. et al.
System: The UNT Digital Library
A high energy neutral beam system for reactors (open access)

A high energy neutral beam system for reactors

High energy neutral beams provide a promising method of heating and driving current in steady-state tokamak fusion reactors. As an example, we have made a conceptual design of a neutral beam system for current drive on the International Thermonuclear Experimental Reactor (ITER). The system, based on electrostatic acceleration of D/sup /minus// ions, can deliver up to 100 MW of 1.6 MeV D/sup 0/ neutrals through three ports. Radiation protection is provided by locating sensitive beamline components 35 to 50 m from the reactor. In an application to a 3300 MW power reactor, a system delivering 120 MW of 2-2.4 MeV deuterium beams assisted by 21 MW of lower hybrid wave power drives 25 MA and provides an adequate plasma power gain (Q = 24) for a commercial fusion power plant. 8 refs., 1 fig., 2 tabs.
Date: September 1, 1988
Creator: Anderson, O. A.; Chan, C. F.; Cooper, W. S.; Leung, K. N.; Lietzke, A. F.; Kim, C. H. et al.
System: The UNT Digital Library
The production of beams from solid materials at the LBL ECR source (open access)

The production of beams from solid materials at the LBL ECR source

Two ovens are described for the feed of vapor from solid materials in the LBL ECR source. A low temperature oven, operating up to 700 /degree/ C, has been used for Li, Mg, P, K, Ca, Ti and Bi. A high temperature oven operating up to 2000/degree/C, has been used for Sc, Fe, Ni, Cu, Ag, La and Tb. At the 1 e..mu..A level the charge states from the oven beams are very close to those from gases. 4 refs., 5 figs., 2 tabs.
Date: September 1, 1988
Creator: Clark, D. J. & Lyneis, C. M.
System: The UNT Digital Library
Pion production in relativistic collisions of nuclear drops (open access)

Pion production in relativistic collisions of nuclear drops

In a continuation of the long-standing effort of the nuclear physics community to model atomic nuclei as droplets of a specialized nuclear fluid, we have developed a hydrodynamic model for simulating the collisions of heavy nuclei at relativistic speeds. Our model couples ideal relativistic hydrodynamics with a new Monte Carlo treatment of dynamic pion production and tracking. The collective flow for low-energy (200 MeV/N) collisions predicted by this model compares favorably with results from earlier hydrodynamic calculations which used quite different numerical techniques. Our pion predictions at these lower energies appear to differ, however, from the experimental data on pion multiplicities. In this case of ultra-relativistic (200 GeV/N) collisions, our hydrodynamic model has produced baryonic matter distributions which are in reasonable agreement with recent experimental data. These results may shed some light on the sensitivity of relativistic collision data to the nuclear equation of state. 20 refs., 12 figs.
Date: September 1, 1988
Creator: Alonso, C. T.; Wilson, J. R.; McAbee, T. L. & Zingman, J. A.
System: The UNT Digital Library
Proceedings of the technical review on advances in geothermal reservoir technology---Research in progress (open access)

Proceedings of the technical review on advances in geothermal reservoir technology---Research in progress

This proceedings contains 20 technical papers and abstracts describing most of the research activities funded by the Department of Energy (DOE's) Geothermal Reservoir Technology Program, which is under the management of Marshall Reed. The meeting was organized in response to several requests made by geothermal industry representatives who wanted to learn more about technical details of the projects supported by the DOE program. Also, this gives them an opportunity to personally discuss research topics with colleagues in the national laboratories and universities.
Date: September 1, 1988
Creator: Lippmann, M.J. (ed.)
System: The UNT Digital Library
Shielding effectiveness of superconductive particles in plastics (open access)

Shielding effectiveness of superconductive particles in plastics

The ability to cool superconductors with liquid nitrogen instead of liquid helium has opened the door to a wide range of research. The well known Meissner effect, which states superconductors are perfectly diamagnetic, suggests shielding applications. One of the drawbacks to the new ceramic superconductors is the brittleness of the finished material. Because of this drawback, any application which required flexibility (e.g., wire and cable) would be impractical. Therefore, this paper presents the results of a preliminary investigation into the shielding effectiveness of YBa/sub 2/Cu/sub 3/O/sub 7-x/ both as a composite and as a monolithic material. Shielding effectiveness was measured using two separate test methods. One tested the magnetic (near field) shielding, and the other tested the electromagnetic (far field) shielding. No shielding was seen in the near field measurements on the composite samples, and only one heavily loaded sample showed some shielding in the far field. The monolithic samples showed a large amount of magnetic shielding. 5 refs., 5 figs.
Date: September 1, 1988
Creator: Pienkowski, T.; Kincaid, J.; Lanagan, M.T.; Poeppel, R.B.; Dusek, J.T.; Shi, D. et al.
System: The UNT Digital Library
PEGASYS: A proposed internal target-spectrometer facility for the PEP storage ring (open access)

PEGASYS: A proposed internal target-spectrometer facility for the PEP storage ring

A proposal for an internal gas-jet target and forward spectrometer for the PEP storage ring is described. The beam structure, allowable luminosity (L=10/sup 33/ cm/sup /minus/2/s/sup /minus/1/ for H/sub 2/, D/sub 2/ decreasing as Z/sup /minus/1.75/ for nuclear targets) and energy (E/sub e/less than or equal to 15 GeV) make the ring ideal for multiparticle coincidence studies in the scaling regime, and where perturbative QCD may be an apt description of some exclusive and semi-inclusive reactions. 17 refs., 5 figs.
Date: September 1, 1988
Creator: Van Bibber, K.
System: The UNT Digital Library
Magnet systems for the International Thermonuclear Experimental Reactor (open access)

Magnet systems for the International Thermonuclear Experimental Reactor

The definition phase for the International Thermonuclear Experimental Reactor (ITER) has been nearly completed, thus beginning a three-year design effort by teams from the European Community (EC), Japan, US, and USSR. Preliminary parameters for the superconducting magnet system have been established to guide more detailed design work. Radiation tolerance of the superconductors and insulators has been important because it sets requirements for the neutron-shield dimension and sensitively influences reactor size. Major levels of mechanical stress appear in the structural cases of the inboard legs of the toroidal-field (TF) coils. The winding packs of the TF coils include significant fractions of steel that provide support against in-plane separating loads, but they offer little support against out-of-plane loads unless shear-bonding of the conductors can be maintained. Heat removal from nuclear and ac loads has not limited the fundamental design, but it has nonnegligible economic consequences. 3 refs., 3 figs., 5 tabs.
Date: September 22, 1988
Creator: Henning, C. D. & Miller, J. R.
System: The UNT Digital Library
The Environmental Effects of Nuclear War (open access)

The Environmental Effects of Nuclear War

Substantial environmental disruption will significantly add to the disastrous consequences caused by the direct thermal, blast, and radiological effects brought on by a major nuclear war. Local fallout could cover several percent of the Northern Hemisphere with potentially lethal doses. Smoke from post-nuclear fires could darken the skies and induce temperature decreases of tens of degrees in continental interiors. Stratospheric ozone could be significantly reduced due to nitric oxide injections and smoke-induced circulation changes. The environmental effects spread the consequences of a nuclear war to the world population, adding to the potentially large disruptive effects a further reason to avoid such a catastrophe. 27 refs., 4 figs.
Date: September 1, 1988
Creator: MacCracken, Michael C.
System: The UNT Digital Library
A non-inductively driven steady state tokamak reactor (open access)

A non-inductively driven steady state tokamak reactor

The physics and engineering guidelines for the ITER device are shown to lead to viable and attractive operating points for a steady state tokamak power reactor. Non-inductive current drive is provided in steady state by high energy neutral beam injection in the plasma core, lower hybrid slow waves in the outer regions of the plasma and bootstrap current. Plasma gain Q (/equivalent to/fusion power/input power) in excess of 20 and average neutron wall loading, <GAMMA> approx. 2.0 MW/m/sup 2/ are predicted in a device with major radius, R/sub 0/ = 7.5 m and minor radius, a = 2.8 m. 15 refs., 3 figs., 3 tabs.
Date: September 20, 1988
Creator: Fenstermacher, M. E.; Devoto, R. S.; Bulmer, R. H.; Lee, J. D.; Miller, J. R. & Schultz, J.
System: The UNT Digital Library
Neutronics analysis of the Laboratory Microfusion Facility (open access)

Neutronics analysis of the Laboratory Microfusion Facility

The radiological safety hazards of the experimental area (EA) for the proposed Inertial Confinement Fusion (ICF) Laboratory Microfusion Facility (LMF) have been examined. The EA includes those structures required to establish the proper pre-shot environment, point the beams, contain the pellet yield, and measure many different facets of the experiments. The radiation dose rates from neutron activation of representative target chamber materials, the laser beam tubes and the argon gas they contain, the air surrounding the chamber, and the concrete walls of the experimental area are given. Combining these results with the allowable dose rates for workers, we show how radiological considerations affect access to the inside of the target chamber and to the diagnostic platform area located outside the chamber. Waste disposal and tritium containment issues are summarized. Other neutronics issues, such as radiation damage to the final optics and neutron heating of materials placed close to the target, are also addressed. 16 refs., 2 figs., 1 tab.
Date: September 19, 1988
Creator: Tobin, M. T.; Singh, M. S. & Meier, W. R.
System: The UNT Digital Library
DPDC (double-pass donor cell): A second-order monotone scheme for advection (open access)

DPDC (double-pass donor cell): A second-order monotone scheme for advection

We are developing a new, second-order, monotone scheme for advection. DPDC (i.e., double-pass donor cell) is based on Smolarkiewicz&#x27; simple, positive definite method. Both schemes are multipass methods in which upstream approximations to the truncation error are subtracted from the equations. We describe two significant improvements to Smolarkiewicz&#x27; method. First, we use a local gauge transformation to convert the method from being positive definite to the stronger condition of being monotone. Second, we analytically approximate the sum of the corrections of all the passes to use in a single corrective pass. This increases the accuracy of the method, but does not increase the order of accuracy. We compare DPDC with van Leer&#x27;s method for advection of several different pulses in a constant velocity field. 5 refs., 4 figs.
Date: September 26, 1988
Creator: Beason, C W & Margolin, L G
System: The UNT Digital Library
The Licensing Experience of the Modular High-Temperature Gas-Cooled Reactor (MHTGR) (open access)

The Licensing Experience of the Modular High-Temperature Gas-Cooled Reactor (MHTGR)

The MHTGR is an advanced reactor concept being developed under a cooperative program involving the US Government, the nuclear industry, and the utilities. The design utilizes the basic HTGR features of ceramic fuel, helium coolant, and a graphite moderator. However, the specific size and configuration are selected to utilize the inherent characteristics of these materials to develop passive safety features that provide a significantly higher margin of safety than current generation reactors. The design meets the US Environmental Protection Agency's Protective Action Guidelines at the site boundary, hence precluding the need for sheltering or vacation of the public during any licensing basis event. This safe behavior is not dependent upon operator action and is insensitive to operator error. The MHTGR Licensing Plan agreed to with the US Nuclear Regulatory Commission (NRC) is discussed with particular attention to the framework of the preapplication review. The objective and scope of each key document prepared for the NRC review is presented. A summary is provided of the safety response to events challenging the functions relied on to retain radionuclides within the coated fuel particles. The regulatory interaction process and results are discussed through the NRC staff, NRC contractor, and ACRS reviews. 11 refs., …
Date: September 1, 1988
Creator: Silady, F.A.; Cunliffe, J.C. & Walker, L.P.
System: The UNT Digital Library
Nuclear effects in J//psi/ and lepton-pair production (open access)

Nuclear effects in J//psi/ and lepton-pair production

High-energy processes in nuclear media provide important tests of quantum chromodynamics, since in principle one can use the nuclear environment to perturb and study the mechanisms involved in confinement and hadronization. In this talk several examples of nuclear effects in QCD will be discussed that affect the propagation and hadronization of quarks and gluons in nuclear matter. The issues include: possible signatures for quark-gluon plasma formation in heavy ion collisions, particularly J//psi/ production; hadronization due to jet coalescence; the limits of validity of QCD factorization formulae due to initial- and final-state interactions; formation zone physics; shadowing of the quark and gluon structure functions of nuclei; and color transparency in hard quasielastic reactions inside of nuclei. 29 refs., 4 figs.
Date: September 1, 1988
Creator: Brodsky, Stanley J.
System: The UNT Digital Library
Aspects of e/sup +/e/sup/minus// physics at 1 TeV (open access)

Aspects of e/sup +/e/sup/minus// physics at 1 TeV

A summary of several recent studies of electroweak e/sup +/e/sup /minus// physics is provided. The significance of upcoming SLC/LEP measurements of Z and W properties is discussed, with special emphasis placed on radiative corrections and polarization. New electroweak physics at a proposed TeV e/sup +/e/sup /minus// collider is presented as a natural outgrowth of the SLC/LEP programs. Precise tests of the trilinear gauge boson vertex through W pair production, searching for the disturbance of perturbative unitarity by radiative corrections, and of the gauge structure of a Z', through polarized e/sup /minus// beams, are presented. 19 refs.
Date: September 1988
Creator: Kennedy, Dallas C.
System: The UNT Digital Library
In situ ion irradiation/implantation studies in the HVEM-Tandem Facility at Argonne National Laboratory (open access)

In situ ion irradiation/implantation studies in the HVEM-Tandem Facility at Argonne National Laboratory

The HVEM-Tandem User Facility at Argonne National Laboratory interfaces two ion accelerators, a 2 MV tandem accelerator and a 650 kV ion implanter, to a 1.2 MV high voltage electron microscope. This combination allows experiments involving simultaneous ion irradiation/ion implantation, electron irradiation and electron microscopy/electron diffraction to be performed. In addition the availability of a variety of microscope sample holders permits these as well as other types of in situ experiments to be performed at temperatures ranging from 10-1300 K, with the sample in a stressed state or with simultaneous determination of electrical resistivity of the specimen. This paper summarizes the details of the Facility which are relevant to simultaneous ion beam material modification and electron microscopy, presents several current applications and briefly describes the straightforward mechanism for potential users to access this US Department of Energy supported facility. 7 refs., 1 fig., 1 tab.
Date: September 1, 1988
Creator: Allen, C. W.; Funk, L. L.; Ryan, E. A. & Taylor, A.
System: The UNT Digital Library
Pioneering the nuclear age (open access)

Pioneering the nuclear age

This paper reviews the historical aspects of nuclear physics. The scientific aspects of the early transuranium elements are discussed and arms control measures are reviewed. 11 refs., 14 figs. (LSP)
Date: September 1, 1988
Creator: Seaborg, G. T.
System: The UNT Digital Library