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Recent US target-physics-related research in heavy-ion inertial fusion: target gains and constraints on accelerator design

Description: Inertial-fusion targets were designed for use with heavy-ion accelerators as drivers in fusion energy power plants. In the interest of providing inputs for understanding the trade-offs among accelerator designs, an initial survey was carried out regarding target gain versus parameters of relevance. This was done in two stages, firstly target gain was related to the beam energy, power, focal radius, and ion range. Secondly, a more comprehensive discussion was made by posing target gain constrain… more
Date: March 9, 1982
Creator: Mark, J.W.K.
Partner: UNT Libraries Government Documents Department
open access

Evolution of the tandem mirror reactor concept

Description: We discuss the evolution of the tandem mirror reactor concept from the original conceptual reactor design (1977) through the first application of the thermal barrier concept to a reactor design (1979) to the beginning of the Mirror Advanced Reactor Study (1982).
Date: March 9, 1982
Creator: Carlson, G. A. & Logan, B. G.
Partner: UNT Libraries Government Documents Department
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Improved Spatial Resolution in Thick, Fully-Depleted CCDs withEnhanced Red Sensitivity

Description: The point spread function (PSF) is an important measure of spatial resolution in CCDs for point-like objects, since it affects image quality and spectroscopic resolution. We present new data and theoretical developments for lateral charge diffusion in thick, fully-depleted charge-coupled devices (CCDs) developed at Lawrence Berkeley National Laboratory (LBNL). Because they can be over-depleted, the LBNL devices have no field-free region and diffusion is controlled through the application of an … more
Date: March 9, 2006
Creator: Fairfield, Jessamyn A.; Groom, Donald E.; Bailey, Stephen J.; Bebek, Christopher J.; Holland, Stephen E.; Karcher, Armin et al.
Partner: UNT Libraries Government Documents Department
open access

Charge-State-Resolved Ion Energy Distribution Functions ofCathodic Vacuum Arcs: A Study Involving the Plasma Potential and BiasedPlasmas

Description: There are divergent results in the literature on the(in)dependence of the ion velocity distribution functions on the ioncharge states. Apparently, most time-of-flight methods of measurementsindicate independence whereas most measurements with electrostaticanalyzers state the opposite. It is shown here that this grouping iscoincidental with investigations of pulsed and continuous arcs. Allresults can be consolidated by taking ion-neutral interaction intoaccount, especially charge exchange collis… more
Date: March 9, 2006
Creator: Anders, Andre & Oks, Efim
Partner: UNT Libraries Government Documents Department
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The 4He Total Photo-Absorption Cross Section With Two- Plus Three-Nucleon Interactions From Chiral Effective Field Theory

Description: The total photo-absorption cross section of {sup 4}He is evaluated microscopically using two- (NN) and three-nucleon (NNN) interactions based upon chiral effective field theory ({chi}EFT). The calculation is performed using the Lorentz integral transform method along with the ab initio no-core shell model approach. An important feature of the present study is the consistency of the NN and NNN interactions and also, through the Siegert theorem, of the two- and three-body current operators. This … more
Date: March 9, 2007
Creator: Quaglioni, S & Navratil, P
Partner: UNT Libraries Government Documents Department
open access

Advanced Test Accelerator (ATA) injector

Description: The ATA injector, developed from experience gained from the Experimental Test Accelerator (ETA) linac, has recently been completed. The injector consists of ten 0.25 MV cells that are used to develop 2.5 MV across a single diode gap. The 10 kA beam is extracted from a 500 cm/sup 2/ plasma cathode at average rates of up to 5 Hz and burst rates to 1 kHz. Pulsed power from 20 water filled blumleins is divided and introduced symmetrically through four ports on each cell. All major insulators are fa… more
Date: March 9, 1983
Creator: Jackson, C. H.; Bubp, D. G.; Fessenden, T. J.; Hester, R. E.; Neil, V. K.; Paul, A. C. et al.
Partner: UNT Libraries Government Documents Department
open access

Summary and viewgraphs from the Q-121 US/Japan advanced current drive concepts workshop

Description: With the emphasis placed on current drive by ITER, which requires steady state operation in its engineering phase, it is important to bring theory and experiment in agreement for each of the schemes that could be used in that design. Both neutral beam and lower hybrid (LH) schemes are in excellent shape in that regard. Since the projected efficiency of all schemes is marginal it is also important to continue our search for more efficient processes. This workshop featured experimental and theore… more
Date: March 9, 1990
Creator: Bonoli, P.; Porkolab, M.; Chan, V.; Pinsker, R.; Politzer, P.; Darrow, D. et al.
Partner: UNT Libraries Government Documents Department
open access

Hydrothermal energy development projects

Description: The development of hydrothermal energy for direct heat applications is being accelerated by twenty-two demonstration projects that are funded on a cost-sharing basis by the US Department of Energy, Division of Geothermal Energy. These projects are designed to demonstrate the technical and economic feasibility of the direct use of hydrothermal resources in the United States. Engineering and economic data for the projects are summarized. The data and experience being generated by these projects w… more
Date: March 9, 1981
Creator: DiBello, E.G.
Partner: UNT Libraries Government Documents Department
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Beam-dump/diagnostics box for a 10-kA 50-MeV, 50-ns electron beam

Description: We have developed a dump for the ATA beam that consists of a series of carbon plates whose collective thickness totals approximately 1.5 ranges at 50 MeV. The energy dissipated in the plates is radiated to a water-cooled wall. The dump is designed to dissipate up to 175 kW of average power. A small hole along the axis of the plates forms a beamlet that passes through an energy analyzer. The analyzer consists of a 60/sup 0/ bending magnet and two high-sensitivity beam-current/position monitors. … more
Date: March 9, 1983
Creator: White, J.M.; Fessenden, T.J.; Fontaine, R.A.; Harvey, A.R. & Paul, A.C.
Partner: UNT Libraries Government Documents Department
open access

Investigating the Affinities and Persistence of VX Nerve Agent in Environmental Matrices

Description: Laboratory experiments were conducted to determine environmental variables that affect the affinities and persistence of the nerve agent O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothiolate (VX) at dilute concentrations in environmental matrices. Quantitative analyses of VX and its degradation products were performed using LC-MS. Batch hydrolysis experiments demonstrated an increasing hydrolysis rate as pH increased, as shown in previous studies, but also indicated that dissolved aqueous… more
Date: March 9, 2004
Creator: Love, A H; Vance, A L; Reynolds, J G & Davisson, M L
Partner: UNT Libraries Government Documents Department
open access

Normalized Texture Motifs and Their Application to Statistical Object Modeling

Description: A fundamental challenge in applying texture features to statistical object modeling is recognizing differently oriented spatial patterns. Rows of moored boats in remote sensed images of harbors should be consistently labeled regardless of the orientation of the harbors, or of the boats within the harbors. This is not straightforward to do, however, when using anisotropic texture features to characterize the spatial patterns. We here propose an elegant solution, termed normalized texture motifs,… more
Date: March 9, 2004
Creator: Newsam, S D
Partner: UNT Libraries Government Documents Department
open access

A technique for accelerating the convergence of restarted GMRES

Description: We have observed that the residual vectors at the end of each restart cycle of restarted GMRES often alternate direction in a cyclic fashion, thereby slowing convergence. We present a new technique for accelerating the convergence of restarted GMRES by disrupting this alternating pattern. The new algorithm resembles a full conjugate gradient method with polynomial preconditioning, and its implementation requires minimal changes to the standard restarted GMRES algorithm.
Date: March 9, 2004
Creator: Baker, A H; Jessup, E R & Manteuffel, T
Partner: UNT Libraries Government Documents Department
open access

COMFEN 3.0 - Evolution of an Early Design Tool for Commercial Facades and Fenestration Systems

Description: Achieving a net-zero energy building cannot be done solely by improving the efficiency of the engineering systems. It also requires consideration of the essential nature of the building including factors such as architectural form, massing, orientation and enclosure. Making informed decisions about the fundamental character of a building requires assessment of the effects of the complex interaction of these factors on the resulting performance of the building. The complexity of these interactio… more
Date: March 9, 2011
Creator: McClintock Facade Consulting LLC, Walnut Creek, CA; McQuillen Interactive LLC, Santa Cruz, CA; Selkowitz, Stephen; Mitchell, Robin; McClintock, Maurya; McQuillen, Daniel et al.
Partner: UNT Libraries Government Documents Department
open access

Novel Perspectives for Hadron Physics

Description: I discuss several novel and unexpected aspects of quantum chromodynamics. These include: (a) the nonperturbative origin of intrinsic strange, charm and bottom quarks in the nucleon at large x; the breakdown of pQCD factorization theorems due to the lensing effects of initial- and final-state interactions; (b) important corrections to pQCD scaling for inclusive reactions due to processes in which hadrons are created at high transverse momentum directly in the hard processes and their relation to… more
Date: March 9, 2012
Creator: Brodsky, Stanley J.
Partner: UNT Libraries Government Documents Department
open access

Probabilistic Threshold Criterion

Description: The Probabilistic Shock Threshold Criterion (PSTC) Project at LLNL develops phenomenological criteria for estimating safety or performance margin on high explosive (HE) initiation in the shock initiation regime, creating tools for safety assessment and design of initiation systems and HE trains in general. Until recently, there has been little foundation for probabilistic assessment of HE initiation scenarios. This work attempts to use probabilistic information that is available from both histo… more
Date: March 9, 2010
Creator: Gresshoff, M & Hrousis, C A
Partner: UNT Libraries Government Documents Department
open access

New hollow-cathode electrode for high-power copper lasers

Description: Multiple hollow-cathode slots were utilized on a profiled solid-copper electrode taht extended stable glow discharge to higher pressures in copper lasers. This novel electrode design, which dramatically reduced discharge jitter and window contamination, has been run for more than 8000 hours with very little degradation.
Date: March 9, 1994
Creator: Chang, J. J.; Alger, T. W.; Anderson, A. T. & Arnold, P. A.
Partner: UNT Libraries Government Documents Department
open access

An investigation of genetic operators for continuous parameter space

Description: The success of a genetic optimization algorithm in continuous parameter space depends on the recombination (crossover) operators that it uses. In this paper we consider a wide spectrum of such operators within a unified framework and study their relative importance in the search process. We consider four basic types recombination operators which cover the relevant exploration potential of a continuous space: Interpolation, Extrapolation, Exchange and Mutation. Each of these basic types may have… more
Date: March 9, 1994
Creator: Grossman, T. & Davidor, Y.
Partner: UNT Libraries Government Documents Department
open access

Photoacoustically Measured Speeds of Sound and the Equation of State of HBO2: On Understanding Detonation with Boron Fuel

Description: Elucidation of geodynamic, geochemical, and shock induced processes is limited by challenges to accurately determine molecular fluid equations of state (EOS). High pressure liquid state reactions of carbon species underlie physiochemical mechanisms such as differentiation of planetary interiors, deep carbon sequestration, propellant deflagration, and shock chemistry. In this proceedings paper we introduce a versatile photoacoustic technique developed to measure accurate and precise speeds of so… more
Date: March 9, 2010
Creator: Zaug, J M; Bastea, S; Crowhurst, J; Armstrong, M; Fried, L & Teslich, N
Partner: UNT Libraries Government Documents Department
open access

Three-Dimensional Magnetohydrodynamic Simulation of Slapper Initiation Systems

Description: Although useful information can be gleaned from 2D and even 1D simulations of slapper type initiation systems, these systems are inherently three-dimensional and therefore require full 3D representation to model all relevant details. Further, such representation provides additional insight into optimizing the design of such devices from a first-principles perspective and can thereby reduce experimental costs. We discuss in this paper several ongoing efforts in modeling these systems, our pursui… more
Date: March 9, 2010
Creator: Christensen, J S & Hrousis, C A
Partner: UNT Libraries Government Documents Department
open access

Deflagration Rates and Molecular Bonding Trends of Statically Compressed Secondary Explosives

Description: We discuss our measurements of the chemical reaction propagation rate as a function of pressure. Materials investigated have included CL-20, HMX, TATB, and RDX crystalline powders, LX-04, Comp B, and nitromethane. The anomalous correspondence between crystal structure, including in some instances isostructural phase transitions, on pressure-dependant RPRs of TATB, HMX, Nitromethane, CL-20, and PETN have been elucidated using micro-IR and -Raman spectroscopies. Here we specifically highlight pre… more
Date: March 9, 2010
Creator: Zaug, J M; Foltz, M F & Hart, E
Partner: UNT Libraries Government Documents Department
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