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Computed and experimental interactions between eddy structure and dispersed particles in developing free shear layers

Description: We are investigating the interactive process between turbulent flow and dispersed phase particles. We are focusing on the mechanisms that appear to result in a reduction of local turbulent intensity and a corresponding reduction in wall heat transfer and subsequent wall erosion in turbulent solid propellant combustion flow. We apply computational simulations and physical experiments specialized to a developing free shear layer over a rearward facing step and over a parallel splitter plate. The … more
Date: May 20, 1982
Creator: Buckingham, A. C.; Siekhaus, W. J.; Keller, J. O.; Ellzey, J.; Hubbard, G. & Daily, J. W.
Partner: UNT Libraries Government Documents Department
open access

Radiation interactions for tomography. Revision 1

Description: There are new requirements emerging in the field of tomography: the need for spatial resolution in the micrometre range, atomic species specificity, and quantitative density discrimination.
Date: May 20, 1985
Creator: Zolnay, A.S.
Partner: UNT Libraries Government Documents Department
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Laser produced plasma soft x-ray generation

Description: The efficiency of soft x-ray production from laser-irradiated plasmas is simulated for two different spectral regions. These two regions, 14{Angstrom} {plus minus} 15% and 130{Angstrom} {plus minus} 1%, were chosen for proximity mask or point-projection technological applications. Relatively large conversion efficiencies were obtained from irradiation of a stainless steel target using the conditions suggested by recent Hampshire Instruments' experiments for proximity masking. Pulse-width and la… more
Date: May 20, 1991
Creator: Cerjan, C. & Rosen, M.D.
Partner: UNT Libraries Government Documents Department
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Cascade ICF power reactor

Description: The double-cone-shaped Cascade reaction chamber rotates at 50 rpm to keep a blanket of ceramic granules in place against the wall as they slide from the poles to the exit slots at the equator. The 1 m-thick blanket consists of layers of carbon, beryllium oxide, and lithium aluminate granules about 1 mm in diameter. The x rays and debris are stopped in the carbon granules; the neutrons are multiplied and moderated in the BeO and breed tritium in the LiAlO/sub 2/. The chamber wall is made up of S… more
Date: May 20, 1986
Creator: Hogan, W.J. & Pitts, J.H.
Partner: UNT Libraries Government Documents Department
open access

Economic studies for heavy-ion-fusion electric power plants

Description: We have conducted parametric economic studies for heavy-ion-fusion electric power plants. We examined the effects on the cost of electricity of several design parameters: cost and cost scaling for the reactor, driver, and target factory; maximum achievable chamber pulse rate; target gain; electric conversion efficiency; and net electric power. Using the most recent estimates for the heavy-ion-driver cost along with the Cascade reactor cost and efficiency, we found that a 1.5 to 3 GWe heavy-ion-… more
Date: May 20, 1986
Creator: Meier, W. R.; Hogan, W. J. & Bangerter, R. O.
Partner: UNT Libraries Government Documents Department
open access

Bounds on Unparticles from the Higgs Sector

Description: We study supersymmetric QCD in the conformal window as a laboratory for unparticle physics, and analyze couplings between the unparticle sector and the Higgs sector. These couplings can lead to the unparticle sector being pushed away from its scale invariant fixed point. We show that this implies that low energy experiments will not be able to see unparticle physics, and the best hope of seeing unparticles is in high energy collider experiments such as the Tevatron and the LHC. We also demonstr… more
Date: May 20, 2007
Creator: Fox, Patrick J.; Rajaraman, Arvind & Shirman, Yuri
Partner: UNT Libraries Government Documents Department
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Bonding, Backbonding, and Spin-Polarized Molecular Orbitals:Basis for Magnetism and Semiconducting Transport in V[TCNE]x~;;2

Description: X-ray absorption spectroscopy (XAS) and magnetic circular dichroism (MCD) at the V L2,3 and C and N K edges reveal bonding/backbonding interactions in films of the 400 K magnetic semiconductor V[TCNE]x~;;2. In V spectra, dxy-like orbitals are modeled assuming V2+ in an octahedral ligand field, while dz2 and dx2-y2 orbitals involved in strong covalent bonding cannot be modeled by atomic calculations. C and N MCD, and differences in XAS from neutral TCNE molecules, reveal spin-polarized molecular… more
Date: May 20, 2008
Creator: Kortright, Jeffrey B.; Lincoln, Derek M.; Edelstein, Ruth Shima & Epstein, Arthur J.
Partner: UNT Libraries Government Documents Department
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EXTRACTION COMPRESSION AND ACCELERATION OF HIGH LINE CHARGE DENSITY ION BEAMS

Description: High Energy Density Physics (HEDP) applications require high line charge density ion beams. An efficient method to obtain this type of beams is to extract a long pulse, high current beam from a gun at high energy, and let the beam pass through a decelerating field to compress it. The low energy beam-bunch is loaded into a solenoid and matched to a Brillouin flow. The Brillouin equilibrium is independent of the energy if the relationship between the beam size (a), solenoid magnetic field strengt… more
Date: May 20, 2005
Creator: Henestroza, Enrique; Henestroza, E.; Peters, C.; Yu, S. S.; Grote, D. P. & Briggs, R. J.
Partner: UNT Libraries Government Documents Department
open access

Progress in Short Period Multilayer Coatings for Water Window Applications

Description: Absolute photoionization cross-section measurements for amixture of ground and metastable states of Xe4+, Xe5+, and Xe6+ arereported in the photon energy range of 4d-nf transitions, which occurwithin or adjacent to the 13.5 nm window for extreme ultravioletlithography light source development. The reported values allow thequantification of opacity effects in xenon plasmas due to these 4d-4fautoionizing states. The oscillator strengths for the 4d-4f and 4d-5ftransitions in Xeq+ (q=1-6) ions are … more
Date: May 20, 2006
Creator: Gullikson, E. M.; Salmassi, F.; Aquila, A. L. & Dollar, F.
Partner: UNT Libraries Government Documents Department
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Suppressed-fission ICF hybrid reactor

Description: A suppressed-fission ICF hybrid reactor has been designed to maximize the production of /sup 233/U. In this design, Be is used as a neutron multiplier. An annular array of Be columns surrounds the fusion pulse inside the reaction chember. The Be columns consist of short cylinders of Be joined together with steel snap rings. Vertical holes in the Be carry liquid lithium coolant and steel-clad thorium fuel pins. The lithium coolant is supplied at the top of the chamber, traverses through the Be c… more
Date: May 20, 1986
Creator: Hogan, W. J. & Meier, W. R.
Partner: UNT Libraries Government Documents Department
open access

Progress in the ICF Program at the Lawrence Livermore National Laboratory

Description: Experiments using the harmonically converted Nd:glass lasers at the Lawrence Livermore National Laboratory (Novette with 2 to 10 kJ at 0.26 and 0.53 micron and Nova with 30 to 80 kJ at 0.35 and 0.53 micron) have demonstrated favorable coupling of laser light to fusion targets. The coupling of short-wavelength laser light to these plasmas is now well understood and is primarily collisional in nature, in contrast to previous experiments at 1.06 microns and 10 microns, where the coupling was colle… more
Date: May 20, 1986
Creator: Hogan, W.J.
Partner: UNT Libraries Government Documents Department
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Fusion-fission hybrid studies in the United States

Description: Systems and conceptual design studies have been carried out on the following three hybrid types: (1) The fission-suppressed hybrid, which maximizes fissile material produced (Pu or /sup 233/U) per unit of total nuclear power by suppressing the fission process and multiplying neutrons by (n,2n) reactions in materials like beryllium. (2) The fast-fission hybrid, which maximizes fissile material produced per unit of fusion power by maximizing fission of /sup 238/U (Pu is produced) in which twice t… more
Date: May 20, 1986
Creator: Moir, R. W.; Lee, J. D.; Berwald, D. H.; Cheng, E. T.; Delene, J. G. & Jassby, D. L.
Partner: UNT Libraries Government Documents Department
open access

Advances in Tandem Mirror fusion power reactors

Description: The Tandem Mirror exhibits several distinctive features which make the reactor embodiment of the principle very attractive: Simple low-technology linear central cell; steady-state operation; high-..beta.. operation; no driven current or disruptions; divertorless operation; direction conversion of end-loss power; low-surface heat loads; and advanced fusion fuel capability. In this paper, we examine these features in connection with two tandem mirror reactor designs, MARS and MINIMARS, and severa… more
Date: May 20, 1986
Creator: Perkins, L. J. & Logan, B. G.
Partner: UNT Libraries Government Documents Department
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Design, implementation, and operation of a class based batch queue scheduler for VAX/VMS

Description: Fermilab found that the standard VMS batch configuration options were inadequate for the job mix that exists on the Fermilab central computer facility VAX cluster. Accordingly, Fermilab designed and implemented a class based batch queue scheduler. This scheduler makes use of the standard VMS job controller and batch system. Users interact with the scheduler at job submission time by specification of CPU time limits and batch job characteristics. This scheduler allows Fermilab to make efficient … more
Date: May 20, 1988
Creator: Chadwick, K.
Partner: UNT Libraries Government Documents Department
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Beam dynamics studies of four-gap low-beta superconducting resonators

Description: The four-gap superconducting resonators which have been developed at Argonne for use in the low-beta positive ion-injector for ATLAS have potential applications for ions with velocities less than 0.007c and q/m less than 0.1. It was previously observed that at low velocities these structures can be focusing in both longitudinal and transverse phase spaces due to an inherent alternating-phase-focusing property. Studies are underway to determine the optimum combination of multi-gap structures and… more
Date: May 20, 1993
Creator: Nolen, J. A. & Joh, K.
Partner: UNT Libraries Government Documents Department
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Sorption and Transport of Iodine Species in Sediments from the Savannah River and Hanford Sites

Description: Iodine is an important element in studies of environmental protection and human health, global-scale hydrologic processes and nuclear nonproliferation. Biogeochemical cycling of iodine is complex, because iodine occurs in multiple oxidation states and as inorganic and organic species that may be hydrophilic, atmophilic, and biophilic. In this study, we focused on the sorption and transport behavior of iodine species (iodide, iodate, and 4-iodoaniline) in sediments collected at the Savannah Rive… more
Date: May 20, 2004
Creator: Hu, Q; Zhao, P; Moran, J & Seaman, J
Partner: UNT Libraries Government Documents Department
open access

Simulation of Chamber Transport for Heavy-Ion Fusion Drivers

Description: The heavy-ion fusion (HIF) community recently developed a power-plant design that meets the various requirements of accelerators, final focus, chamber transport, and targets. The point design is intended to minimize physics risk and is certainly not optimal for the cost of electricity. Recent chamber-transport simulations, however, indicate that changes in the beam ion species, the convergence angle, and the emittance might allow more-economical designs.
Date: May 20, 2004
Creator: Sharp, W. M.; Callahan, D. A.; Tabak, M.; Yu, S. S.; Peterson, P. F.; Rose, D. V. et al.
Partner: UNT Libraries Government Documents Department
open access

Structural Characterization and Lifetime Stability of Mo/Y Extreme Ultraviolet Multilayer Mirrors

Description: We observe a dramatic dependence of the extreme ultraviolet (EUV) reflectivity of Mo/Y multilayers on the oxygen content of yttrium. This is explained by a change in microstructure, increase in roughness of the Y layers and not by an increase in absorption due to oxygen in Y layers. We find best reflectivity of 38.4% is achieved with an oxygen content of 25%, which reduces to 32.6% and 29.6% for multilayers manufactured from oxygen free yttrium and 39%-oxygen yttrium, respectively. These result… more
Date: May 20, 2004
Creator: Kjornrattanawanich, B & Bajt, S
Partner: UNT Libraries Government Documents Department
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A Neutron Source Facility for Neutron Cross-Section Measurements on Radioactive Targets at RIA

Description: The stockpile stewardship program is interested in neutron cross-section measurements on nuclei that are a few nucleons away from stability. Since neutron targets do not exist, radioactive targets are the only way to directly perform these measurements. This requires a facility that can provide high production rates for these short-lived nuclei as well as a source of neutrons. The Rare Isotope Accelerator (RIA) promises theses high production rates. Thus, adding a co-located neutron source faci… more
Date: May 20, 2003
Creator: Ahle, L. E.; Bernstein, L.; Rusnak, B. & Berio, R.
Partner: UNT Libraries Government Documents Department
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Irradiation Effects on RIA Fragmentation CU Beam Dump

Description: Within the scope of conceptual research and development (R&D) activities in support of the Rare Isotope Accelerator (RIA) facility, high priority is given to the development of high-power fragmentation beam dumps. A pre-study was made of a static water-cooled Cu beam dump that can meet requirements for a 400 MeV/u uranium beam. The issue of beam sputtering was addressed and found to be insignificant. Preliminary radiation transport simulations show significant damage (in displacements per a… more
Date: May 20, 2005
Creator: Reyes, S.; Boles, J. L.; Ahle, L. E.; Stein, W. & Wirth, B. D.
Partner: UNT Libraries Government Documents Department
open access

Shielding of a hadron in a finite e-beam

Description: The thorough study of coherent electron cooling, the modern cooling technique capable to deal with accelerators operating in the range of few TeVs, rises many interesting questions. One of them is a shielding dynamics of a hadron in an electron beam. Now this effect is computed analytically in the infinite beam approximation. Many effects are drastically different in finite and infinite plasmas. Here we propose a method to compute the dynamical shielding effect in a finite cylindrical plasma - … more
Date: May 20, 2012
Creator: A., Elizarov; Litvinenko, V. & Wang, G.
Partner: UNT Libraries Government Documents Department
open access

Effects of grids in drift tubes

Description: In 2011, we upgraded a 201 MHz buncher in the proton injector for the alternating gradient synchrotron (AGS) - relativistic heavy ion collider (RHIC) complex. In the buncher we installed four grids made of tungsten to improve the transit time factor. The grid installed drift tubes have 32 mm of inner diameter and the each grid consists of four quadrants. The quadrants were cut out precisely from 1mm thick tungsten plates by a computerized numerically controlled (CNC) wire cutting electrical dis… more
Date: May 20, 2012
Creator: M., Okamura & Yamauchi, H.
Partner: UNT Libraries Government Documents Department
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