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Analytical methods of electrode design for a relativistic electron gun

Description: The standard paraxial ray equation method for the design of electrodes for an electrostatically focused gun is extended to include relativistic effects and the effects of the beam's azimuthal magnetic field. Solutions for parallel and converging beams are obtained and the predicted currents are compared against those measured on the High Brightness Test Stand. 4 refs., 2 figs.
Date: May 9, 1985
Creator: Caporaso, G.J.; Cole, A.G. & Boyd, J.K.
Partner: UNT Libraries Government Documents Department
open access

Numerical simulation of an accelerator injector

Description: Accelerator injector designs have been evaluated using two computer codes. The first code self consistently follows relativistic particles in two dimensions. Fields are obtained in the Darwin model which includes inductive effects. This code is used to study cathode emission and acceleration to full injector voltage. The second code transports a fixed segment of a beam along the remainder of the beam line. Using these two codes the effects of electrode configuration on emittance, beam quality a… more
Date: May 9, 1985
Creator: Boyd, J.K.; Caporaso, G.J. & Cole, A.G.
Partner: UNT Libraries Government Documents Department
open access

Brightness measurements on the Livermore high brightness test stand

Description: Several techniques using small radius collimating pipes with and without axial magnetic fields to measure the brightness of an extracted 1 - 2 kA, 1 - 1.5 MeV electron beam will be described. The output beam of the High Brightness Test Stand as measured by one of these techniques is in excess of 2 x 10/sup 5/ amp/cm/sup 2//steradian. 5 refs., 4 figs.
Date: May 9, 1985
Creator: Caporaso, G.J. & Birx, D.L.
Partner: UNT Libraries Government Documents Department
open access

X-ray streak camera temporal resolution improvement using a longitudinal time-dependent field

Description: X-ray streak cameras (XSC) have been known to be one of the fastest detectors forultrafast X-ray science. A number of applications in material science, biochemistry, accelerator physics, require sub-picosecond resolution to study new phenomena. Inthis paper, we report on a new method which can potentially improve the temporal resolution of a streak camera down to 100 femtoseconds. This method uses a time-dependent acceleration field to lengthen the photoelectron bunch, significantlyimproving th… more
Date: May 9, 2008
Creator: Qiang, Ji; Qiang, J.; Byrd, J.M.; Feng, J. & Huang, G.
Partner: UNT Libraries Government Documents Department
open access

A Vlasov Solver for Longitudinal Dynamics in Beam Delivery Systems for X-Ray FELs

Description: Direct numerical methods for solving the Vlasov equationoffer some advantages over macroparticle simulations, as they do notsuffer from the consequences of the statistical fluctuations inherent inusing a number of macroparticles smaller than thebunch population.Unfortunately these methods are more time-consuming and generallyconsidered impractical in a full 6D phase space. However, in alower-dimension phase space they may become attractive if the beamdynamics is sensitive to the presence of sma… more
Date: May 9, 2007
Creator: Venturini, Marco; Warnock, Robert & Zholents, Alexander
Partner: UNT Libraries Government Documents Department
open access

Elastic Scattering of Low-Energy Electrons byTetrahydrofuran

Description: We present the results of ab initio calculations for elasticelectron scattering by tetrahydrofuran (THF) using the complex Kohnvariational method. We carried out fixed-nuclei calculations at theequilibrium geometry of the target molecule for incident electronenergies up to 20 eV. The calculated momentum transfer cross sectionsclearly reveal the presence of broad shape resonance behavior in the 8-10eV energy range, in agreement with recent experiments. The calculateddifferential cross sections a… more
Date: May 9, 2006
Creator: Trevisan, Cynthia S.; Orel, Ann E. & Rescigno, Thomas N.
Partner: UNT Libraries Government Documents Department
open access

Characteristics of CoxTi1-xO2 thin films deposited by MOCVD

Description: This paper deals with the growth and characterization of ferromagnetic cobalt doped TiO{sub 2} thin films deposited by liquid precursor metal organic chemical vapor deposition (MOCVD) using a new combination of the source materials Co(TMHD){sub 3}, tetrahydrofuran (THF), and titanium isopropoxide (TIP). An array of experiments reveals the intrinsic ferromagnetic nature of the grown films, and suggests that the magnetism is not generated by oxygen vacancies.
Date: May 9, 2008
Creator: McClure, A.; Kayani, A.; Idzerda, Y.U.; Arenholz, E. & Cruz, E.
Partner: UNT Libraries Government Documents Department
open access

Visualization Tools for Adaptive Mesh Refinement Data

Description: Adaptive Mesh Refinement (AMR) is a highly effective method for simulations that span a large range of spatiotemporal scales, such as astrophysical simulations that must accommodate ranges from interstellar to sub-planetary. Most mainstream visualization tools still lack support for AMR as a first class data type and AMR code teams use custom built applications for AMR visualization. The Department of Energy's (DOE's) Science Discovery through Advanced Computing (SciDAC) Visualization and Analy… more
Date: May 9, 2007
Creator: Weber, Gunther H.; Beckner, Vincent E.; Childs, Hank; Ligocki,Terry J.; Miller, Mark C.; Van Straalen, Brian et al.
Partner: UNT Libraries Government Documents Department
open access

FLUIDIZED BED STEAM REFORMING ENABLING ORGANIC HIGH LEVEL WASTE DISPOSAL

Description: Waste streams planned for generation by the Global Nuclear Energy Partnership (GNEP) and existing radioactive High Level Waste (HLW) streams containing organic compounds such as the Tank 48H waste stream at Savannah River Site have completed simulant and radioactive testing, respectfully, by Savannah River National Laboratory (SRNL). GNEP waste streams will include up to 53 wt% organic compounds and nitrates up to 56 wt%. Decomposition of high nitrate streams requires reducing conditions, e.g. … more
Date: May 9, 2008
Creator: Williams, M
Partner: UNT Libraries Government Documents Department
open access

Renewables Portfolio Standards: A Factual Introduction toExperience from the United States

Description: Renewables portfolio standards (RPS) have--since the late 1990s--proliferated at the state level in the United States. What began as a policy idea minted in California and first described in detail in the pages of the 'Electricity Journal' FPT has emerged as an important driver for renewable energy capacity additions in the United States. Over the years, articles in the 'Electricity Journal' have explored the RPS in more detail, identifying both its strengths and weaknesses. The present article… more
Date: May 9, 2007
Creator: Wiser, R.; Namovicz, C.; Gielecki, M. & Smith, R.
Partner: UNT Libraries Government Documents Department
open access

Modeling of LH current drive in self-consistent elongated tokamak MHD equilibria

Description: Calculations of non-inductive current drive typically have been used with model MHD equilibria which are independently generated from an assumed toroidal current profile or from a fit to an experiment. Such a method can lead to serious errors since the driven current can dramatically alter the equilibrium and changes in the equilibrium B-fields can dramatically alter the current drive. The latter effect is quite pronounced in LH current drive where the ray trajectories are sensitive to the loca… more
Date: May 9, 1989
Creator: Blackfield, D. T.; Devoto, R. S.; Fenstermacher, M. E.; Bonoli, P. T.; Porkolab, M. & Yugo, J.
Partner: UNT Libraries Government Documents Department
open access

Modular invariant gaugino condensation

Description: The construction of effective supergravity lagrangians for gaugino condensation is reviewed and recent results are presented that are consistent with modular invariance and yield a positive definite potential of the noscale type. Possible implications for phenomenology are briefly discussed. 29 refs.
Date: May 9, 1991
Creator: Gaillard, M. K.
Partner: UNT Libraries Government Documents Department
open access

Nuclear hazardous waste cost control management

Description: The effects of the waste content of glass waste forms on Savannah River high-level waste disposal costs are currently under study to adjust the glass frit content to optimize the glass waste loadings and therefore significantly reduce the overall waste disposal cost. Changes in waste content affect onsite Defense Waste Changes in waste contents affect onsite Defense Waste Processing Facility (DWPF) costs as well as offsite shipping and repository emplacement charges. A nominal 1% increase over … more
Date: May 9, 1991
Creator: Selg, R.A.
Partner: UNT Libraries Government Documents Department
open access

New concepts for drift pumping a thermal barrier with rf

Description: Pump neutral beams, which are directed into the loss cone of the TMX-U plugs, are normally used to pump ions from the thermal barriers. Because these neutral beams introduce cold gas that reduces pumping efficiency, and require a straight line entrance and exit from the plug, alternate methods are being investigated to provide barrier pumping. To maintain the thermal barrier, either of two classes of particles can be pumped. First, the collisionally trapped ions can be pumped directly. In this … more
Date: May 9, 1985
Creator: Barter, J.D.; Baldwin, D.; Chen, Y. & Poulsen, P.
Partner: UNT Libraries Government Documents Department
open access

Interrelationships between man, energy, and water quality: a new methodology for integrative analyses

Description: The STORET/MSP option was used to obtain county aggregated information on ambient water quality for sixty parameters during the period 1950 to 1978. Masks, extended EXTRACT specifications and bounds on allowable values limited inclusion of erroneous data. Remark codes were required to aggregate STORET parameters to obtain increased numbers of observations. Numerous statistical analyses led to the conclusions that medians were more useful than means, that trimming on number of observations was r… more
Date: May 9, 1979
Creator: Kaplan, E. & Thode, H.C. Jr.
Partner: UNT Libraries Government Documents Department
open access

Application of muon spin relaxation experiment to the mixed state superconductors

Description: We discuss the use of muon spin relaxation ({mu}{sup +}SR) technique to study the mixed state of superconductors. Besides the application for static vortex configurations, we argue that large vortex motion can manifest itself as a narrowed time-averaged field distribution, which in turn results in a smaller relaxation rate. A static but disordered vortex configuration can also reduce the relaxation. We summarize these arguments. 7 refs.
Date: May 9, 1991
Creator: Inui, M. (Los Alamos National Lab., NM (USA)) & Harshman, D.R. (AT and T Bell Labs., Murray Hill, NJ (USA))
Partner: UNT Libraries Government Documents Department
open access

Nuclear-data needs for inertial-confinement fusion (ICF)

Description: Our survey was limited to ICF programs in the United States. It included researchers in laser and heavy ion fusion, target design, target diagnostics, and conceptual reactor design. We asked each of these people to read the current data needs for magnetic fusion energy and to comment on additional data that they require.
Date: May 9, 1983
Creator: Haight, R. C. & Motz, H. T.
Partner: UNT Libraries Government Documents Department
open access

Large P sub t jets at CDF

Description: The inclusive jet cross section and the dijet mass spectrum have been measured at the Fermilab Tevatron Collider at {radical}s = 1.8 TeV. These measurements span approximately 7 orders of magnitude in cross section and contain jets up to 400 GeV in transverse energy and dijet masses up to 950 GeV. Comparisons have been made to QCD at both orders {alpha}{sub s}{sup 2} and {alpha}{sub s}{sup 3}. 8 refs., 9 figs.
Date: May 9, 1990
Creator: Dell'Orso, M. (Pisa Univ. (Italy). Dipt. di Fisica)
Partner: UNT Libraries Government Documents Department
open access

Fracture Surface Area Effects on Fluid Extraction and the Electrical Resistivity of Geothermal Reservoir Rocks

Description: Laboratory measurements of the electrical resistivity of fractured analogue geothermal reservoir rocks were performed to investigate the resistivity contrast caused by active boiling and to determine the effects of variable fracture dimensions and surface area on water extraction. Experiments were performed at confining pressures up to 10 h4Pa (100 bars) and temperatures to 170 C. Fractured samples show a larger resistivity change at the onset of boiling than intact samples. Monitoring the resi… more
Date: May 9, 2002
Creator: Roberts, J. J.; Detwiler, R. L.; Ralph, W. & Bonner, B.
Partner: UNT Libraries Government Documents Department
open access

Beam Transport in a Compact Dielectric Wall Induction Accelerator System for Pulsed Radiography

Description: Using dielectric wall accelerator technology, we are developing a compact induction accelerator system primarily intended for pulsed radiography. The accelerator would provide a 2-kA beam with an energy of 8 MeV, for a 20-30 ns flat-top. The design goal is to generate a 2-mm diameter, 10-rad x-ray source. We have a physics design of the system from injector to the x-ray converter. We present the results of injector modeling and PIC simulations of beam transport. We also discuss the predicted sp… more
Date: May 9, 2005
Creator: McCarrick, J. F.; Caporaso, G. J. & Chen, Y.
Partner: UNT Libraries Government Documents Department
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