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Analytical model for the dynamic resistivity of electrically-exploded conductors

Description: A detailed model for the dynamic resistivity of an exploding conductor presents many difficulties. An electrically-exploded conductor undergoes significant hydrodynamic expansion as it is heated. Resistivity is a function of both the temperature and density of a conductor and realistic models for resistivity over the range of parameter space experienced by an exploding conductor are quite complex. See for example, the model of Lee and More (1984). Calculation of the hydrodynamic expansion of th… more
Date: October 10, 1986
Creator: Lee, R. S.
Partner: UNT Libraries Government Documents Department
open access

Scaling of current density, total current, emittance, and brightness for hydrogen negative ion sources

Description: The atomic and molecular processes that play a principal role in negative ion formation in a hydrogen negative ion discharge are discussed. The collisions of energetic electrons with gas molecules within the discharge lead to vibrationally excited molecules. Thermal electrons in turn attach to these excited molecules and generate negative ions via the dissociative attachment process. A system geometry chosen to optimize these collision processes is discussed that consists of a high-power discha… more
Date: July 10, 1986
Creator: Hiskes, J.R.
Partner: UNT Libraries Government Documents Department
open access

Giant resonance phenomena in the electron impact ionization of heavy atoms and ions

Description: Heavy atoms and ions offer an interesting opportunity to study atomic physics in a region where the atomic structure is dominated by the interelectronic interactions. One illustration of this is the profound term dependence of atomic orbitals for certain configurations of heavy atoms and ions. The appearance of giant scattering resonances in the cross sections for ionization of heavy atoms by electron impact is a manifestation of resonance behavior. Such resonant structures arise from the doubl… more
Date: June 10, 1986
Creator: Younger, S.M.
Partner: UNT Libraries Government Documents Department
open access

Use of single-cutter data in the analysis of PDC bit designs

Description: A method is developed for predicting cutter forces, temperatures, and wear on PDC bits as well as integrated bit performance parameters such as weight-on-bit (WOB), drilling torque, and bit imbalance. A computer code called PDCWEAR has been developed to make this method available as a tool for general bit design. The method uses single-cutter data to provide a measure of rock drillability and employs theoretical considerations to account for interaction among closely spaced cutters on the bit. … more
Date: October 10, 1986
Creator: Glowka, D.A.
Partner: UNT Libraries Government Documents Department
open access

Complex defects in the oxidation of uranium

Description: We are reporting EPR results obtained with uranium powder samples fully oxidized in dry air, water vapor, and air/water vapor mixtures. The results reported previously are confirmed and additional paramagnetic centers, associated with chemisorbed species, have been identified. The temperature dependence of the g-value for these centers from room temperature to 10K is also reported.
Date: June 10, 1986
Creator: MacCrone, R. K.; Sankaran, S.; Shatynski, S. R. & Colmenares, C. A.
Partner: UNT Libraries Government Documents Department
open access

Design considerations for a combined synchrotron-light source and heavy-ion storage ring Atomic Physics Facility

Description: An Atomic Physics Facility (APF) based on the combination of photons produced by a synchrotron light source with heavy ions in a storage ring will open the way to the study of ionic states of almost all elements. The design considerations for such a facility are discussed in terms of the use of synchrotron radiation for photoexcitation and ionization experiments. Design considerations for an APF are given in terms of the accelerator facilities presently available at BNL which include the Nation… more
Date: November 10, 1986
Creator: Jones, K. W.; Johnson, B. M.; Meron, M.; Lee, Y. Y.; Thieberger, P. & Thomlinson, W. C.
Partner: UNT Libraries Government Documents Department
open access

Neutron scattering on nuclei near A = 60 and A = 90

Description: Over a wide range of incident energies, the total cross section and angular distributions for elastic scattering of neutrons from nuclei in these mass regions are analyzed using the spherical-optical-statistical model. The effect of a real-surface-peaked potential, predicted by dispersion relations, is considered. It is found that when the data on a given nucleus between say, 4.5 and 10 MeV, are analyzed simultaneously one obtains a smooth energy variation of the optical model parameters. Moreo… more
Date: October 10, 1986
Creator: Lawson, R. D. & Smith, A. B.
Partner: UNT Libraries Government Documents Department
open access

Materials technology applied to nuclear accelerator targets

Description: The continuing requests for both shaped and flat, very low areal density metal foils have led to the development of metallurgical quality, high strength products. Intent of this paper is to show methods of forming structures on various substrates using periodic vapor interruptions, alternating anodes, and mechanical peening to alter otherwise unacceptable grain morphology which both lowers tensile strength and causes high stresses in thin films. The three technologies, physical vapor deposition… more
Date: November 10, 1986
Creator: Barthell, Barry L.
Partner: UNT Libraries Government Documents Department
open access

Trace Element Measurements Using White Synchrotron Radiation

Description: Synchrotron radiation, when used for x-ray fluorescence (XRF) has several advantages over conventional x-ray sources. Our group at Brookhaven National Laboratory is developing the equipment and expertise to make XRF measurements with synchrotron radiation. The apparatus is briefly described, along with the alignment techniques. Some minimum detectable limits for trace elements in thin biological standards measured with white light irradiations are presented.
Date: November 10, 1986
Creator: Hanson, A. L.; Jones, K. W.; Gordon, B. M.; Pounds, J. G.; Kwiatek, W. M.; Long, G. J. et al.
Partner: UNT Libraries Government Documents Department
open access

Glass Making Technology for High-Level Nuclear Waste

Description: This paper addresses specific and unique chemical engineering aspects of the Defense Waste Processing Facility (DWPF) at the Savannah River Plant. This paper also addresses the glass melter and those processes that are directly coupled to it. A somewhat disproportionate emphasis is given to sludge pretreatment, for the sake of completeness in this session. We have attempted to focus on those features of the DWPF that may be of general interest or even useful to the practicing chemical engineer.
Date: July 10, 1986
Creator: Boersma, M. D. & Mahoney, J. L.
Partner: UNT Libraries Government Documents Department
open access

The Savannah River Site and the Processing Facility Being Built to Prepare its Radioactive Waste for Permanent Disposal

Description: This presentation provides an appreciation for the tremendous chemical processing challenges met in the development of the Defense Waste Process Facility (DWPF) process. The DWPF is presently under construction and is due for completion in 1989. Before radioactive waste is introduced to the DWPF in late 1989, the remote operation of all equipment and all process steps must be demonstrated.
Date: July 10, 1986
Creator: Knight, J. R.
Partner: UNT Libraries Government Documents Department
open access

Crystallographic Considerations of the Delta in Equilibrium. cap alpha. Displacive Transformation in Plutonium Alloys

Description: Determination of invariant-plane strain crystallographic solutions for martensitic transformation between the FCC delta and monoclinic ..cap alpha.. phases in plutonium alloys, using three possible lattice correspondences and 53 possible lattice-invariant shear systems, identifies the most probable delta-..cap alpha.. lattice correspondence. The operative lattice-invariant shear systems are predicted by comparison of both shape strain magnitudes and computed interfacial energies. For delta ..--… more
Date: June 10, 1986
Creator: Adler, P. H. & Olson, G. B.
Partner: UNT Libraries Government Documents Department
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