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318,998 Matching Results
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A 2 to 4 nm high power FEL on the SLAC linac
We report the results of preliminary studies of a 2 to 4 nm SASE FEL, using a photoinjector to produce the electron beam, and the SLAC linac to accelerate it to an energy up to 10 GeV. Longitudinal bunch compression is used to increases ten fold the peak current to 2.5 kA, while reducing the bunch length to the subpicosecond range. The saturated output power is in the multi-gigawatt range, producing about 10{sup 14} coherent photons within a bandwidth of about 0.2% rms, in a pulse of several millijoules. At 120Hz repetition rate the average power is about 1 W. The system is optimized for x-ray microscopy in the water window around 2 to 4 nm, and will permit imaging a biological sample in a single subpicosecond pulse.
Date:
September 1, 1992
Creator:
Pellegrini, C.; Rosenzweig, J.; Nuhn, H. D.; Pianetta, P.; Tatchyn, R.; Winick, H. et al.
Object Type:
Article
System:
The UNT Digital Library
2 x 2 Polyethylene Reflected and Moderated Highly Enriched Uranium System with Rhenium
The 2 × 2 array HEU-Re experiment was performed on the Planet universal critical assembly machine on November 4th, 2003 at the Los Alamos Critical Experiments Facility (LACEF) at Los Alamos National Laboratory (LANL). For this experiment, there were 10 ½ units, each full unit containing four HEU foils and two rhenium foils. The top unit contained only two HEU foils and two rhenium foils. A total of 42 HEU foils were used for this experiment. Rhenium is a desirable cladding material for space nuclear power applications. This experiment consisted of HEU foils interleaved with rhenium foils and is moderated and reflected by polyethylene plates. A unit consisted of a polyethylene plate, which has a recess for rhenium foils, and four HEU foils in a single layer in the top recess of each polyethylene plate. The Planet universal criticality assembly machine has been previously used in experiments containing HEU foils interspersed with SiO2 (HEU-MET-THERM-001), Al (HEU-MET-THERM-008), MgO (HEU-MET-THERM-009), Gd foils (HEU-MET-THERM-010), 2 × 2 × 26 Al (HEU-MET-THERM-012), Fe (HEU-MET-THERM-013 and HEU-MET-THERM-015), 2 × 2 × 23 SiO2 (HEU-MET-THERM-014), 2 × 2 × 11 hastalloy plates (HEU-MET-THERM-016), and concrete (HEU-MET-THERM-018). The 2 × 2 array of HEU-Re is considered acceptable …
Date:
September 1, 2010
Creator:
Ellis, A. Nichole; Hutchinson, Jesson; Bess, John D.; Polyakov, Dmitry N.; Glushkov, Evgeny S. & Glushkov, Alexey E.
Object Type:
Report
System:
The UNT Digital Library
2 x 2 TeV mu(superscript +) mu (superscript) collider
The scenarios for high-luminosity 2 x 2 TeV and 250 x 250 GeV {mu}{sup +}{mu}{sup -} colliders are presented. Having a high physics potential, such a machine has specific physics and technical advantages and disadvantages when compared with an e{sup +}e{sup -} collider. Parameters for the candidate designs and the basic components - proton source, pion production and decay channel, cooling, acceleration and collider storage ring - are considered. Attention is paid to the areas mostly affecting the collider performance: targetry, energy spread, superconducting magnet survival, detector backgrounds, polarization, environmental issues. 13 refs., 9 figs., 4 tabs.
Date:
October 1, 1996
Creator:
Mokhov, N. V. & Noble, R. J.
Object Type:
Article
System:
The UNT Digital Library
3.1.1.2 Feed Processing and Handling DL2 Final Report
This milestone report is the deliverable for our Feed Processing and Handling project. It includes results of wet biomass feedstock analysis, slurry pumping information, fungal processing to produce a lignin-rich biorefinery residue and two subcontracted efforts to quantify the amount of wet biomass feedstocks currently available within the corn processing and paper processing industries.
Date:
September 30, 2006
Creator:
Elliott, Douglas C.; Magnuson, Jon K. & Wend, Christopher F.
Object Type:
Report
System:
The UNT Digital Library
3,2-HOPO Complexes of Near-Infra-Red (NIR) Emitting Lanthanides: Sensitization of Ho(III) and Pr(III) in Aqueous Solution
There is a growing interest in Near Infra-Red (NIR) emission originating from organic complexes of Ln{sup III} cations. As a major impetus, biological tissues are considerably more transparent at these low energy wavelengths when compared to visible radiation, which facilitates deeper penetration of incident and emitted light. Furthermore, the long luminescence lifetimes of Ln{sup III} complexes (eg. Yb{sup III}, {tau}{sub rad} {approx} 1 ms) when compared to typical organic molecules can be utilized to vastly improve signal to noise ratios by employing time-gating techniques. While the improved quantum yield of Yb{sub III} complexes when compared to other NIR emitters favors their use for bioimaging applications, there has also been significant interest in the sensitized emission from other 4f metals such as Ln = Nd, Ho, Pr and Er which have well recognized applications as solid state laser materials (eg. Nd {approx} 1.06 {micro}m, Ho {approx} 2.09 {micro}m), and in telecommunications (eg. Er {approx} 1.54 {micro}m) where they can be used for amplification of optical signals. As a result of their weak (Laporte forbidden) f-f absorptions, the direct excitation of Ln{sup III} cations is inefficient, and sensitization of the metal emission is more effectively achieved using the so-called antenna effect. We …
Date:
May 19, 2008
Creator:
Moore, Evan G.; Szigethy, Geza; Xu, Jide; Palsson, Lars-Olof; Beeby, Andrew & Raymond, Kenneth N.
Object Type:
Article
System:
The UNT Digital Library
A 3.3 MJ, Rb + 1 driver design based on an integrated systems analysis
A computer model for systems analysis of heavy ion drivers has been developed and used to evaluate driver designs for inertial fusion energy (IFE). The present work examines a driver for a close-coupled target design that requires less total beam energy but also smaller beam spots sizes than previous target designs. Design parameters and a cost estimate for a 160 beam, 3.3 MJ driver using rubidium ions (A = 85) are reported, and the sensitivity of the results to variations in selected design parameters is given.
Date:
March 7, 2000
Creator:
Meier, W. R.; Barnard, J. J. & Bangerter, R. O.
Object Type:
Article
System:
The UNT Digital Library
A 3.3 MJ, Rb{sup +1} Driver Design Based on an Integrated Systems Analysis
A computer model for systems analysis of heavy ion drivers has been developed and used to evaluate driver designs for inertial fusion energy (IFE). The present work examines a driver for a close-coupled target design that requires less total beam energy but also smaller beam spots sizes than previous target designs. Design parameters and a cost estimate for a 160 beam, 3.3 MJ driver using rubidium ions (A = 85) are reported, and the sensitivity of the results to variations in selected design parameters is given.
Date:
September 15, 2000
Creator:
Meier, W. R.; Barnard, J. J. & Bangerter, R. O.
Object Type:
Article
System:
The UNT Digital Library
3,4,3-LI(1,2-HOPO): In Vitro Formation of Highly Stable Lanthanide Complexes Translates into Efficacious In Vivo Europium Decorporation
The spermine-based hydroxypyridonate octadentate chelator 3,4,3-LI(1,2-HOPO) was investigated for its ability to act as an antennae that sensitizes the emission of Sm{sup III}, Eu{sup III}, and Tb{sup III} in the Visible range (Φ{sub tot} = 0.2 - 7%) and the emission of Pr{sup III}, Nd{sup III}, Sm{sup III}, and Yb{sup III} in the Near Infra-Red range, with decay times varying from 1.78 μs to 805 μs at room temperature. The particular luminescence spectroscopic properties of these lanthanide complexes formed with 3,4,3-LI(1,2-HOPO) were used to characterize their respective solution thermodynamic stabilities as well as those of the corresponding La{sup III}, Gd{sup III}, Dy{sup III}, Ho{sup III}, Er{sup III}, Tm{sup III}, and Lu{sup III} complexes. The remarkably high affinity of 3,4,3-LI(1,2-HOPO) for lanthanide metal ions and the resulting high complex stabilities (pM values ranging from 17.2 for La{sup III} to 23.1 for Yb{sup III}) constitute a necessary but not sufficient criteria to consider this octadentate ligand an optimal candidate for in vivo metal decorporation. The in vivo lanthanide complex stability and decorporation capacity of the ligand were assessed, using the radioactive isotope {sup 152}Eu as a tracer in a rodent model, which provided a direct comparison with the in vitro thermodynamic results …
Date:
July 13, 2011
Creator:
Sturzbecher-Hoehne, Manuel; Ng Pak Leung, Clara; Daleo, Anthony; Kullgren, Birgitta; Prigent, Anne-Laure; Shuh, David K. et al.
Object Type:
Article
System:
The UNT Digital Library
$3.5 Million in Savings Identified in Appleton Assessment: Plant-Wide Assessment Summary--Forest Products (Fact Sheet)
Summary of Appleton Paper, Inc.'s plant-wide assessment to identify energy and cost saving opportunities at the corporation's paper mill in West Carrollton, Ohio.
Date:
August 1, 2003
Creator:
unknown
Object Type:
Text
System:
The UNT Digital Library
$3.6 Million in Savings Identified in AMCAST Assessment (Revised)
Summary of AMCAST Industrial Corporation's plant-wide assessment to identify energy and cost saving opportunities at the corporation's facility in Wapakoneta, Ohio.
Date:
August 1, 2004
Creator:
unknown
Object Type:
Text
System:
The UNT Digital Library
3. 6 simplified methods for design
Simplified design analysis methods for elevated temperature construction are classified and reviewed. Because the major impetus for developing elevated temperature design methodology during the past ten years has been the LMFBR program, considerable emphasis is placed upon results from this source. The operating characteristics of the LMFBR are such that cycles of severe transient thermal stresses can be interspersed with normal elevated temperature operational periods of significant duration, leading to a combination of plastic and creep deformation. The various simplified methods are organized into two general categories, depending upon whether it is the material, or constitutive, model that is reduced, or the geometric modeling that is simplified. Because the elastic representation of material behavior is so prevalent, an entire section is devoted to elastic analysis methods. Finally, the validation of the simplified procedures is discussed.
Date:
January 1, 1981
Creator:
Nickell, R.E. & Yahr, G.T.
Object Type:
Article
System:
The UNT Digital Library
3.9 GHz superconducting accelerating 9-cell cavity vertical test results
The 3rd harmonic 3.9GHz accelerating cavity was proposed to improve the beam performance of the FLASH (TTF/DESY) facility [1]. In the frame of a collaborative agreement, Fermilab will provide DESY with a cryomodule containing a string of four cavities. In addition, a second cryomodule with one cavity will be fabricated for installation in the Fermilab photo-injector, which will be upgraded for the ILC accelerator test facility. The first 9-cell Nb cavities were tested in a vertical setup and they didn't reach the designed accelerating gradient [2]. The main problem was a multipactor in the HOM couplers, which lead to overheating and quenching of the HOM couplers. New HOM couplers with improved design are integrated in the next 9-cell cavities. In this paper we present all results of the vertical tests.
Date:
June 1, 2007
Creator:
Khabiboulline, Timergali; Cooper, Charles; Dhanaraj, Nandhini; Edwards, Helen; Foley, Mike; Harms, Elvin et al.
Object Type:
Article
System:
The UNT Digital Library
3.9 GHz superconducting accelerating 9-cell cavity vertical test results
None
Date:
June 1, 2007
Creator:
Khabiboulline, Timergali; Cooper, Charles; Dhanaraj, Nandhini; Edwards, Helen; Foley, Mike; Harms, Elvin et al.
Object Type:
Article
System:
The UNT Digital Library
3-10 keV and 0. 1- to 2-MeV observations of four gamma-ray bursts
Four catalogued ..gamma..-ray bursts that occurred between 79/3/7 and 79/7/31 have been observed over the 3 to 10 keV range by a joint NRL/Los Alamos experiment on the Air Force P78-1 satellite. The bursts were also well observed by members of the interplanetary network. In this paper we present hardness ratios, x-ray/..gamma..-ray luminosity ratios, and time histories. The most significant results presented herein can be summarized as follows: (1) gamma-ray bursters can emit fairly strongly at x-ray energies near the time of the ..gamma.. burst with L/sub x//L/sub ..gamma../ approx. .02 (L/sub x/ approx. 10/sup 37/ ergs s/sup -1/, 3 to 10 keV, assuming a distance of 1 kpc); (2) the centroid of the x-ray emission generally lags the ..gamma..-ray centroid, but there is also evidence for one or more types of x-ray precursor activity; (3) the ..gamma..-ray hardness ratios were not highly variable for these particular events. However, there is some evidence that the ..gamma..-ray spectra softened near the ends of the bursts when the x-ray/..gamma..-ray ratios were high; (4) the x-ray/..gamma..-ray power law number index during times of the strongest ..gamma..-ray emission ranged from 0.8 to approx. 1.1 for the four bursts; (5) the x-ray tail of GB790307 …
Date:
January 1, 1983
Creator:
Laros, J. G.; Evans, W. D.; Fenimore, E. E.; Klebesadel, R. W.; Shulman, S. & Fritz, G.
Object Type:
Article
System:
The UNT Digital Library
A 3-Axis Force Balanced Accelerometer Using a Single Proof-Mass
This paper presents a new method for wideband force balancing a proof-mass in multiple axes simultaneously. Capacitive position sense and force feedback are accomplished using the same air-gap capacitors through time multiplexing. Proof of concept is experimentally demonstrated with a single-mass monolithic surface micromachined 3-axis accelerometer.
Date:
April 1997
Creator:
Lemkin, M.A.; Boser, B.E.; Auslander, D. & Smith, J.
Object Type:
Article
System:
The UNT Digital Library
3-body final states in peripheral heavy-ion collisions: nuclear clustering structure and projectile excitation revisited
Even though peripheral heavy-ion collisions are less violent than their central counterparts, the large energy exchange between the reactants often leaves the primary products in excited particle-unstable states whose subsequent decay leads to 3 or more nuclei emerging in the final exit channel. These post-reaction, predominantly sequential de-excitation processes can sometimes provide interesting structural information about the parent nuclei. In fact, provided these processes are well understood, one can employ them as probes for studying initial properties of the fragments. This report discusses results of two experiments that deal with (1) nonstatistical, rare decay modes of the projectile, and (2) internal excitation energy of the projectile- and target-like fragments in peripheral collisions. The physics addressed in each is different, but the experimental and data-analysis techniques are so similar that it is relevant to join them together.
Date:
February 1, 1986
Creator:
Chan, Y.; Chavez, E.; Gazes, S.B.; Kamermans, R.; Schmidt, H.R.; Siwek-Wilczynska, J. et al.
Object Type:
Article
System:
The UNT Digital Library
A 3-D adaptive mesh refinement algorithm for multimaterial gas dynamics
Adaptive Mesh Refinement (AMR) in conjunction with high order upwind finite difference methods has been used effectively on a variety of problems. In this paper we discuss an implementation of an AMR finite difference method that solves the equations of gas dynamics with two material species in three dimensions. An equation for the evolution of volume fractions augments the gas dynamics system. The material interface is preserved and tracked from the volume fractions using a piecewise linear reconstruction technique. 14 refs., 4 figs.
Date:
August 12, 1991
Creator:
Puckett, E. G. & Saltzman, J. S.
Object Type:
Article
System:
The UNT Digital Library
3-D Analysis on Arbitrarily-Shaped Icrf Antennas and Faraday Shields
Cavity antennas with Faraday shields are proposed to couple ion cyclotron radio frequency power for heating fusion plasmas. This application requires small, high-power, low-frequency antennas. The results are presented of a theoretical study of the ICRF antennas being developed for this purpose at the Radio Frequency Test Facility (RFTF). The objectives of this work are to optimize experimental designs and to confirm test results. (MOW)
Date:
January 1, 1986
Creator:
Chen, G. L.; Whealton, J. H.; Baity, F. W.; Hoffman, D. J. & Owens, T. L.
Object Type:
Article
System:
The UNT Digital Library
3-D Cavern Enlargement Analyses
Three-dimensional finite element analyses simulate the mechanical response of enlarging existing caverns at the Strategic Petroleum Reserve (SPR). The caverns are located in Gulf Coast salt domes and are enlarged by leaching during oil drawdowns as fresh water is injected to displace the crude oil from the caverns. The current criteria adopted by the SPR limits cavern usage to 5 drawdowns (leaches). As a base case, 5 leaches were modeled over a 25 year period to roughly double the volume of a 19 cavern field. Thirteen additional leaches where then simulated until caverns approached coalescence. The cavern field approximated the geometries and geologic properties found at the West Hackberry site. This enabled comparisons are data collected over nearly 20 years to analysis predictions. The analyses closely predicted the measured surface subsidence and cavern closure rates as inferred from historic well head pressures. This provided the necessary assurance that the model displacements, strains, and stresses are accurate. However, the cavern field has not yet experienced the large scale drawdowns being simulated. Should they occur in the future, code predictions should be validated with actual field behavior at that time. The simulations were performed using JAS3D, a three dimensional finite element analysis …
Date:
March 1, 2002
Creator:
EHGARTNER, BRIAN L. & SOBOLIK, STEVEN R.
Object Type:
Report
System:
The UNT Digital Library
3-D Characterization of the Structure of Paper and Paperboard and Their Application to Optimize Drying and Water Removal Processes and End-Use Applications
The three dimensional structure of paper materials plays a critical role in the paper manufacturing process especially via its impact on the transport properties for fluids. Dewatering of the wet web, pressing and drying will benefit from knowledge of the relationships between the web structure and its transport coefficients. The structure of the pore space within a paper sheet is imaged in serial sections using x-ray micro computed tomography. The three dimensional structure is reconstructed from these sections using digital image processing techniques. The structure is then analyzed by measuring traditional descriptors for the pore space such as specific surface area and porosity. A sequence of microtomographs was imaged at approximately 2 m intervals and the three-dimensional pore-fiber structure was reconstructed. The pore size distributions for both in-plane as well as transverse pores were measured. Significant differences in the in-plane (XY) and the transverse directions in pore characteristics are found and may help partly explain the different liquid and vapor transport properties in the in-plane and transverse directions. Results with varying sheet structures compare favorably with conventional mercury intrusion porosimetry data. Interestingly, the transverse pore structure appears to be more open with larger pore size distribution compared to the in …
Date:
August 29, 2004
Creator:
Shri Ramaswamy, University of Minnesota & B.V. Ramarao, State University of New York
Object Type:
Report
System:
The UNT Digital Library
3-D Combinatorial Geometry in the MERCURY Monte Carlo Particle Transport Code
Lawrence Livermore National Laboratory is in the process of developing a new Monte Carlo Particle Transport code named MERCURY. This new code features a 3-D Combinatorial Geometry tracking algorithm. This paper details some of the characteristics of this Monte Carlo tracker
Date:
September 27, 2004
Creator:
Greenman, G
Object Type:
Article
System:
The UNT Digital Library
3-D Computations and Measurements of Accelerator Magnets for the APS
The Advanced Photon Source (APS), now under construction at Argonne National Laboratory (ANL), requires dipole, quadrupole, sextupole, and corrector magnets for each of its circular accelerator systems. Three-dimensional (3-D) field computations are needed to eliminate unwanted multipole fields from the ends of long quadrupole and dipole magnets and to guarantee that the flux levels in the poles of short magnets will not cause saturation. Measurements of the magnets show good agreement with the computations.
Date:
1993-11~
Creator:
Turner, L. R.; Kim, S. H. & Kim, K.
Object Type:
Article
System:
The UNT Digital Library
3-D computer simulations of EM field sin the APS vacuum chamber. Part 2: Time-domain analysis
Our simulations suggest that the strong peak around 4 GHz in the narrow gap observed in the measurements is generated by TE modes. Therefore, one should not worry about this peak insofar as the coupling impedance is concerned. On the other hand, some discrepancies between our simulations and the measurements are noticed and remain to be resolved.
Date:
January 20, 1989
Creator:
Chou, W.
Object Type:
Report
System:
The UNT Digital Library
3-D computer simulations of EM fields in the APS vacuum chamber: Part 1, Frequency-domain analysis
The vacuum chamber proposed for the storage ring of the 7-GeV Advanced Photon Source (APS) basically consists of two parts: the beam chamber and the antechamber, connected to each other by a narrow gap. A sector of 1-meter-long chamber with dosed end plates, to which are attached the 1-inch-diameter beampipes centered at the beam chamber, has been built for experimental purposes. The 3-D code MAFIA has been used to simulate the frequency-domain behaviors of EM fields in this setup. The results are summarized in this note and are compared with that previously obtained from 2-D simulations and that from network analyzer measurements. They are in general agreement. A parallel analysis in the time-domain is reported in a separate note. The method of our simulations can be briefly described as follows. The 1-inch diameter beampipes are terminated by conducting walls at a length of 2 cm. The whole geometry can thus be considered as a cavity. The lowest RF modes of this geometry are computed using MAFIA. The eigenfrequencies of these modes are a direct output of the eigenvalue solver E3, whereas the type of each mode is determined by employing the postprocessor P3. The mesh sizes are chosen such that …
Date:
September 4, 1990
Creator:
Chou, W. & Bridges, J.
Object Type:
Report
System:
The UNT Digital Library