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0.5 {mu}m E/D AlGaAs/GaAs heterostructure field effect transistor technology with DFET threshold adjust implant
A doped-channel heterostructure field effect transistor (H-FET) technology has been developed with self-aligned refractory gate processing and using both enhancement- and depletion-mode transistors. D-HFET devices are obtained with a threshold voltage adjust implant into material designed for E-HFET operation. Both E- and D-HFETs utilize W/WSi bilayer gates, sidewall spacers, and rapid thermal annealing for controlling short channel effects. The 0.5 {mu}m E- HFETs (D-HFETs) have been demonstrated with transconductance of 425 mS/mm (265-310 mS/mm) and f{sub t} of 45-50 GHz. Ring oscillator gate delays of 19 ps with a power of 0.6 mW have been demonstrated using direct coupled FET logic. These results are comparable to previous doped-channel HFET devices and circuits fabricated by selective reactive ion etching rather than ion implantation for threshold voltage adjustment. digital.library.unt.edu/ark:/67531/metadc686113/
0.7-eV GaInAs Junction for a GaInP/GaAs/GaInAs(1-eV)/GaInAs(0.7-eV) Four-Junction Solar Cell: Preprint
We discuss recent developments in III-V multijunction solar cells, focusing on adding a fourth junction to the Ga0.5In0.5P/GaAs/Ga0.75In0.25As inverted three-junction cell. This cell, grown inverted on GaAs so that the lattice-mismatched Ga0.75In0.25As third junction is the last one grown, has demonstrated 38% efficiency, and 40% is likely in the near future. To achieve still further gains, a lower-bandgap GaxIn1-xAs fourth junction could be added to the three-junction structure for a four-junction cell whose efficiency could exceed 45% under concentration. Here, we present the initial development of the GaxIn1-xAs fourth junction. Junctions of various bandgaps ranging from 0.88 to 0.73 eV were grown, in order to study the effect of the different amounts of lattice mismatch. At a bandgap of 0.88 eV, junctions were obtained with very encouraging {approx}80% quantum efficiency, 57% fill factor, and 0.36 eV open-circuit voltage. The device performance degrades with decreasing bandgap (i.e., increasing lattice mismatch). We model the four-junction device efficiency vs. fourth junction bandgap to show that an 0.7-eV fourth-junction bandgap, while optimal if it could be achieved in practice, is not necessary; an 0.9-eV bandgap would still permit significant gains in multijunction cell efficiency while being easier to achieve than the lower-bandgap junction. digital.library.unt.edu/ark:/67531/metadc883629/
The 0.22 Percent Across-the-Board Cut in FY2001 Appropriations
Report describing changes that affected the government budget for the 2001 fiscal year under the Consolidated Appropriations Act. digital.library.unt.edu/ark:/67531/metacrs1440/
The 0.38 Percent Across-the-Board Cut in FY2000 Appropriations
This report outlines cuts made in the federal budget for FY2000. The 0.38% cut was expected to yield savings of $2.4 billion in budget authority and$1.4 billion in outlays for the fiscal year. Departments with cuts in excess of $100 million included the Departments of Defense, Transportation, Health and Human Services, and Education. digital.library.unt.edu/ark:/67531/metacrs1083/ 0.351 micron Laser Beam propagation in High-temperature Plasmas A study of the laser-plasma interaction processes have been performed in plasmas that are created to emulate the plasma conditions in indirect drive inertial confinement fusion targets. The plasma emulator is produced in a gas-filled hohlraum; a blue 351-nm laser beam propagates along the axis of the hohlraum interacting with a high-temperature (T{sub e} = 3.5 keV), dense (n{sub e} = 5 x 10{sup 20}cm{sup -3}), long-scale length (L {approx} 2 mm) plasma. Experiments at these conditions have demonstrated that the interaction beam produces less than 1% total backscatter resulting in transmission greater than 90% for laser intensities less than I &lt; 2 x 10{sup 15} W-cm{sup -2}. The bulk plasma conditions have been independently characterized using Thomson scattering where the peak electron temperatures are shown to scale with the hohlraum heater beam energy in the range from 2 keV to 3.5 keV. This feature has allowed us to determine the thresholds for both backscattering and filamentation instabilities; the former measured with absolutely calibrated full aperture backscatter and near backscatter diagnostics and the latter with a transmitted beam diagnostics. A plasma length scaling is also investigated extending our measurements to 4-mm long high-temperature plasmas. At intensities I &lt; 5 x 10{sup 14} W-cm{sup -2}, greater than 80% of the energy in the laser is transmitted through a 5-mm long, high-temperature (T{sub e} &gt; 2.5 keV) high-density (n{sub e} = 5 x 10{sup 20} w-cm{sup -3}) plasma. Comparing the experimental results with detailed gain calculations for the onset of significant laser scattering processes shows a stimulated Brillouin scattering threshold (R=10%) for a linear gain of 15; these high temperature, low density experiments produce plasma conditions comparable to those along the outer beams in ignition hohlraum designs. By increasing the gas fill density (n{sub e} = 10{sup 21} cm{sup -3}) in these targets, the inner beam ignition hohlraum conditions are accessed. In this case, stimulated Raman scattering dominates the backscattering processes and we show that scattering is small for gains less than 20 which can be achieved through proper choice of the laser beam intensity. The first three-dimensional (3D) simulations of a high power 0.351 {micro}m laser beam propagating through a high-temperature hohlraum plasma are also reported. We show that 3D linear kinetic modeling of Stimulated Brillouin scattering reproduces quantitatively the experimental measurements, provided it is coupled to detailed hydrodynamics simulation and a realistic description of the laser beam from its millimeter-size envelop down to the micron scale speckles. These simulations accurately predict the strong reduction of SBS measured when polarization smoothing is used. digital.library.unt.edu/ark:/67531/metadc897677/ 0.25mm-thick CCD packaging for the Dark Energy Survey Camera array The Dark Energy Survey Camera focal plane array will consist of 62 2k x 4k CCDs with a pixel size of 15 microns and a silicon thickness of 250 microns for use at wavelengths between 400 and 1000 nm. Bare CCD die will be received from the Lawrence Berkeley National Laboratory (LBNL). At the Fermi National Accelerator Laboratory, the bare die will be packaged into a custom back-side-illuminated module design. Cold probe data from LBNL will be used to select the CCDs to be packaged. The module design utilizes an aluminum nitride readout board and spacer and an Invar foot. A module flatness of 3 microns over small (1 sqcm) areas and less than 10 microns over neighboring areas on a CCD are required for uniform images over the focal plane. A confocal chromatic inspection system is being developed to precisely measure flatness over a grid up to 300 x 300 mm. This system will be utilized to inspect not only room-temperature modules, but also cold individual modules and partial arrays through flat dewar windows. digital.library.unt.edu/ark:/67531/metadc887388/ 0.52eV Quaternary InGaAsSb Thermophotovoltaic Diode Technology Thermophotovoltaic (TPV) diodes fabricated from 0.52eV lattice-matched InGaAsSb alloys are grown by Metal Organic Vapor Phase Epitaxy (MOVPE) on GaSb substrates. 4cm{sup 2} multi-chip diode modules with front-surface spectral filters were tested in a vacuum cavity and attained measured efficiency and power density of 19% and 0.58 W/cm{sup 2} respectively at operating at temperatures of T{sub radiator} = 950 C and T{sub diode} = 27 C. Device modeling and minority carrier lifetime measurements of double heterostructure lifetime specimens indicate that diode conversion efficiency is limited predominantly by interface recombination and photon energy loss to the GaSb substrate and back ohmic contact. Recent improvements to the diode include lattice-matched p-type AlGaAsSb passivating layers with interface recombination velocities less than 100 cm/s and new processing techniques enabling thinned substrates and back surface reflectors. Modeling predictions of these improvements to the diode architecture indicate that conversion efficiencies from 27-30% and {approx}0.85 W/cm{sup 2} could be attained under the above operating temperatures. digital.library.unt.edu/ark:/67531/metadc788112/ T = 0 AND T = 1 PAIRING IN LIGHT NUCLEI. No Description digital.library.unt.edu/ark:/67531/metadc867649/$D^0 \bar{D}^0$Mixing at BaBar This article reviews the recent measurement of D{sup 0}-{bar D}{sup 0} mixing with the D{sup 0} {yields} K{pi} decay channel from the BABAR experiment at the PEP-II B-Factory. Averages from the Heavy Flavor Averaging Group between this result and a previous result from BELLE are also presented. digital.library.unt.edu/ark:/67531/metadc846481/ D-0 End Calorimeter Warm Tube/TeV Dry Air Purge This Engineering Note studies the design of the Dry Air Purge that is going to flow through the Warm Tube of the End Calorimeter of the D-O Calorimeter. The Tev tubes through the E.C. can be thought of as a cluster of concentric tubes: The Tev tube, the warm (vacuum vessel) tube, 15 layers of superinsulation, the cold (argon vessel) tube, and the Inner Hadronic center support tube. The Dry Air Purge will involve flowing Dry Air through the annular region between the Warm Tube and the Tev Beam Pipe. This air flow is intended to prevent condensation from forming in this region which could turn to ice under cryogenic temperatures. Any ice formed in this gap, could cause serious problems when these tubes are moved. The Air will flow through a Nylon Tube Fitting -1/4-inch I.D. to 1/8-inch male pipe thread (Cole Palmer YB-06465-15) see Drawing MC-295221 (Appendix A). This fitting will be attached to the Nylon 2-inch Tube-Wiper and Seal Assembly which is clamped to the ends of the Warm Tube (Appendix A). This note includes drawings and calculations that explain the setup of the Dry Air Purge and give the required information on the pressure drops through the setup. The Equations and properties used in the calculations were obtained from the Applied Fluid Dynamics Handbook by Robert D. Blevins and Fluid Dynamics Second Edition by Frank M. White. digital.library.unt.edu/ark:/67531/metadc840985/$D^0$hot topics The authors present recent D0 results based on approximately 1 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV recorded at the Fermilab Tevatron. Preliminary results on a search for the flavor changing neutral current process D{sup +} {yields} {pi}{sup +}{mu}{sup +}{mu}{sup -}, a measurement of the Cp violation parameter in B mixing, {epsilon}{sub B}, and a two sided limit on the B{sub s} oscillation frequency {Delta}m{sub s} are presented. The limits on {epsilon}{sub B} and {Beta}(D{sup +} {yields} {pi}{sup +}{mu}{sup +}{mu}{sup -}) are the world's best limits. The two sided bound on {Delta}m{sub s} is the first direct indication by a single experiment that {Delta}m{sub s} is bounded from above. digital.library.unt.edu/ark:/67531/metadc881618/ D-0 North End Cap Calorimeter Cold Test Results The North endcap calorimeter vessel was recieved on July 1, 1990. A cooldown of the pressure vessel with liquid nitrogen was performed on July 10-11 to check the vessel's integrity. With the pressure vessel cold, the insulating vacuum was monitored for leaks. Through out the testing, the insulating vacuum remained good and the vessel passed the test. The cold test was carried out per the procedures of D-Zero engineering note 3740.220-EN-250. The test was very similar to the cold test performed on the Central Calorimeter in October of 1987. Reference D-Zero engineering notes 3740.210-EN-122, 3740.000-EN107, and 3740.210-EN-110 for information about the CC cold test. The insulating vacuum space was pumped on while equipment was being connected to the pressure vessel. Two hours after starting to pump with the blower the vacuum space pressure was at about 210 microns. Pumping on the vacuum space for the next 15 hours showed no progress and a leak detector was connected to the pumping line. A leak check showed a leak in a thermocouple feedthru on the vacuum space relief plate. After fixing the leak, the pressure dropped to 16 microns in less than one hour. A rate of rise test was performed starting at a pressure of 13 microns. The pressure rose to 39 microns within 8 minutes and then only rose to 43 microns in 2.5 hours (1.6 microns/hour). After all connections were made to the pressure vessel, a vacuum pump with an estimated effective pumping speed of about 70 scfm was valved on. The lowest pressure achieved after 2 days of pumping was 80 microns. Valving out the pump for 30 minutes resulted in a 5 micron per minute rate of rise. The rate of rise was considered acceptable since there were known leak paths through the bolts of the signal ports. The EC North vessel was rolled outside of Lab A in preparation for a 5000 gallon liquid nitrogen trailer which arrived July, 10 at 8:00am. Before filling the vessel, the vacuum space pump was valved off. The pressure in the vacuum space was 12 microns at that point. During the next 24 hours of the test, the vacuum space pressure decreased to 5 microns. A plot of the vacuum space pressure with time is included at the end of this note. The liquid nitrogen was pressure transferred from the trailer at 29 psig to the pressure vessel at 1 psig for ten hours. At that time there was sufficient (16-inch) of liquid nitrogen in the vessel to turn the LN2 trailer delivery pump on. Thirteen and one half hours after starting the fill, the vessel had 50-inch of LN2 collected. During the latter part of the filling, about twelve loud metallic bangs were heard. The noises came at random intervals with sometimes five minutes between and other times an hour between. The best way to describe the sound is to imagine the sound made if someone was trapped inside the vessel with a baseball bat and took a good swing. The trailer was disconnected and the the vessel was left overnight for ten hours. Due to the slow LN2 fill rate, the temperature gradient in the pressure vessel shell was not very large, only about 25 kelvin difference was found from a RTD in the warm-up nozzle of the vessel and the resistors of the liquid level probe. A temperature versus time graph is included at the end of this note. digital.library.unt.edu/ark:/67531/metadc831688/ D-0 South End Cap Calorimeter Cold Test Results The South endcap calorimeter vessel was moved into Lab A on Sept. 18, 1990. A cooldown of the pressure vessel with liquid nitrogen was performed on Sept. 26 to check the vessel's integrity. With the pressure vessel cold, the insulating vacuum was monitored for leaks. Through out the testing, the insulating vacuum remained good and the vessel passed the test. The cold test was carried out per the procedures of D-Zero engineering note 3740.220-EN-250. The test was very similar to the cold test performed on the Central Calorimeter in October of 1987. The test of the ECS was performed in the same manner using the same equipment as the ECN cold test. Reference D-Zero engineering notes 3740.210-EN-122, 3740.000-EN-I07, and 3740.210-EN-II0 for information about the CC cold test. Reference EN-260 for the results of the ECN cold test. The insulating vacuum space was pumped on while equipment was being connected to the pressure vessel. Two hours after starting to pump with the blower the vacuum space pressure was at about 40 microns. The pumping continued overnight (another 16 hours). In the morning the pressure was 11.5 microns. A rate of rise test was performed. With the pump valved off, the pressure rose to 14 microns within 5 minutes and then rose to 16 microns in 6 hours (0.33 microns/hour). After all connections were made to the pressure vessel, a vacuum pump with an estimated effective pumping speed of about 70 scfm was valved on. After 18 hours, the pressure vessel was down to 270 microns. An additional day of pumping took the pressure down to only 250 microns. A leak was then found and fixed around the seal of the rupture disc. The pump was put on line again. The pressure vessel with pump on line was 27 microns after 16.5 hours. A rate of rise was then conducted. The pressure was 90 microns after valving out the pump. After 30 minutes the pressure increased to 107 microns. (34 microns/hr). digital.library.unt.edu/ark:/67531/metadc838127/ 1.1-meter bore, 8-Tesla test facility The design and fabrication of a 1.1-m bore superconducting coil for an 8- T facility at Lawrence Livermore Laboratory are discussed. This facility will provide the backing field required for testing large multifilamentary Nb$sub 3$Sn coils as part of the superconductor development program at Livermore. The magnet measures 1.85 m o.d., is 1.5 m in length, and is solenoid wound in four separate modules. Total cold weight of the assembly is 18,000 Kg. A NbTi superconductor is used throughout with a gradation of current density within the magnet to provide complete cryostatic stability. The preliminary design of a large 3500-A multifilamentary Nb$sub 3$Sn insert magnet is also included. Together, the backing coil and insert magnets are designed to produce a 12-T central field in a 0.4m bore. The ''equal area'' theory of cryostatic stability is applied in the design of both magnet systems and is discussed in detail. A large open-mouth cryostat is used and measures 2 m in diameter and 3.7 m in length. Details of Dewar design and the refrigeration requirements are included. (auth) digital.library.unt.edu/ark:/67531/metadc870470/ 1.1 Simulations of a Free-Electron Laser Oscillator at Jefferson Lab Lasing in the Vacuum Ultraviolet The UVFEL at Jefferson Lab has provided a 10 eV photon beam for users by outcoupling the coherent third harmonic of the UVFEL operated at 372 nm. This can provide up to tens of milliwatts of power in the VUV. Operation of the FEL at the fundamental might enhance this power by up to a factor of 1000. With minor upgrades to the accelerator now underway and a new undulator proposed by Calabazas Creek Research, Inc. we show that we can lase in the fundamental at 124 nm. The predicted output is higher by four orders of magnitude on an average power basis and six orders of magnitude on a peak fluence basis than the Advanced Light Source at Lawrence Berkeley National Laboratory. digital.library.unt.edu/ark:/67531/metadc832248/ 1/2 CREEP FRACTURE IN CERAMIC POLYCRYSTALS I. CREEP CAVITATION EFFECTS IN POLYCRYSTALLINE ALUMINA Fine grained polycrystalline alumina has been deformed in creep at high temperatures, to examine the evolution of cavities at grain boundaries. Cavities with equilibrium and crack-like morphologies have been observed, distributed non-uniformly throughout the material. The role of cavities during creep has been described. A transition from equilibrium to crack-like morphology has been observed and correlated with a model based on the influence of the surface to boundary diffusivity ratio and the local tensile stress. The contribution of cavitation to the creep rate and total creep strain has been analyzed and excluded as the principal cause of the observed non-linear creep rate, digital.library.unt.edu/ark:/67531/metadc837524/ 1,2-HOIQO--A highly versatile 1,2-HOPO analog A cyclic, bidentate hydroxamic acid binding unit based on an isoquinoline scaffold has been utilized for the synthesis of a hexadentate tripodal ligand based on the TREN backbone. This prototype for a new class of multidentate chelators forms mononuclear iron(III) complexes and one-dimensional coordination polymers with lanthanide(III) cations. The latter has been determined by single crystal X-ray analysis of the cerium species. The solid state structure in the monoclinic space group P2{sub 1}/c (C{sub 36}H{sub 34}CeN{sub 7}O{sub 11}, a = 12.341(2){angstrom}, b = 26.649(4){angstrom}, c = 10.621(2){angstrom}, {alpha} = {gamma} = 90{sup o}, {beta} = 96.753(3){sup o}, V = 3468.6(9) {angstrom}{sup 3}, Z = 4) exhibits a trigonal-dodecahedral environment around the cerium cation. The proof of concept for the versatility of the new scaffold has been shown by the modification of the crucial precursor 3-carboxyiso-coumarin through electrophilic aromatic substitutions to yield the corresponding chlorosulfonated and nitrated analogs. digital.library.unt.edu/ark:/67531/metadc897341/ 1,2-Hydroxypyridonates as Contrast Agents for Magnetic ResonanceImaging: TREN-1,2-HOPO 1,2-Hydroxypyridinones (1,2-HOPO) form very stable lanthanide complexes that may be useful as contrast agents for Magnetic Resonance Imaging (MRI). X-ray diffraction of single crystals established that the solid state structures of the Eu(III) and the previously reported [Inorg. Chem. 2004, 43, 5452] Gd(III) complex are identical. The recently discovered sensitizing properties of 1,2-HOPO chelates for Eu(III) luminescence allow direct measurement of the number if water molecules in the metal complex. Fluorescence measurements of the Eu(III) complex corroborate that in solution two water molecules coordinate the lanthanide (q = 2) as proposed from the analysis of NMRD profiles. In addition, fluorescence measurements have verified the anion binding interactions of lanthanide TREN-1,2-HOPO complexes in solution, studied by relaxivity, revealing only very weak oxalate binding (K{sub A} = 82.7 {+-} 6.5 M{sup -1}). Solution thermodynamic studies of the metal complex and free ligand have been carried out using potentiometry, spectrophotometry and fluorescence spectroscopy. The metal ion selectivity of TREN-1,2-HOPO supports the feasibility of using 1,2-HOPO ligands for selective lanthanide binding [pGd = 19.3 (2); pZn = 15.2 (2), pCa = 8.8 (3)]. digital.library.unt.edu/ark:/67531/metadc900304/ 1.2 MW klystron for Asymmetric Storage Ring B Factory A cw klystron operating at 476 MHz has been developed jointly by SLAC and Varian Associates. The unique set of characteristics of this tube were strongly guided by requirements of the fast feedback necessary to prevent oscillations of the storage ring beams caused by the detuned accelerating cavity. This requires a combination of bandwidth and short group delay within the klystron. The RF feedback stabilization scheme also requires amplitude modulation making it necessary to operate the klystron about 10% below saturation. Performance specifications and initial operating results are presented. digital.library.unt.edu/ark:/67531/metadc666784/ 1/2 SINTERING OF MULLITE-CONTAINING MATERIALS: I. EFFECT OF COMPOSITION Sintering behavior of mullite-containing powders was studied over a range of chemical compositions (Al{sub 2}O{sub 3}/SiO{sub 2} ratio). Densification measurements were made for both liquid phase-containing and solid state systems. Small amounts of liquid phase were observed to have a significant effect on densification rate. A linear relationship was obtained between the percent of theoretical density and the logarithm of time for compositions in the range 73-75 wt% Al{sub 2}O{sub 3}. Currently available models for intermediate stage sintering kinetics were considered to be inadequate for these systems. Grain boundary transport 0r diffusion appeared to be the primary mechanism of densification. digital.library.unt.edu/ark:/67531/metadc870305/ 1.3 GHz superconducting RF cavity program at Fermilab At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules (CMs) for Project X, an International Linear Collider (ILC), or other future projects. The 1.3 GHz SRF cavity program includes targeted R&amp;D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described. digital.library.unt.edu/ark:/67531/metadc832738/ 1,3-Propanediol Made From Fermentation-Derived Malonic Acid: Office of Industrial Technologies (OIT) Agriculture Project Fact Sheet 1,3-Propanediol is one of two ingredients used in producing polytrimethylene terephthalate (PTT), a polymer which can be used in polyester and nylon applications. Researchers are developing a process to ferment biomass feedstock to malonic acid using filamentous fungi and then catalytically convert malonic acid to 1,3-propanediol. digital.library.unt.edu/ark:/67531/metadc716125/ A 1.5 GeV compact light source with superconducting bending magnets This paper describes the design of a compact electron synchrotron light source for producing X-rays for medical imaging, protein crystallography, nano-machining and other uses up to 35 keV. The source will provide synchrotron light from six 6.9 tesla superconducting 60{degree} bending magnet stations. In addition the ring, contains conventional quadrupoles and sextupoles. The light source has a circumference of 26 meters, which permits it to be located in a variety of industrial and medical facilities. digital.library.unt.edu/ark:/67531/metadc793152/ 1.5-GeV FFAG Accelerator for the AGS Facility N/A digital.library.unt.edu/ark:/67531/metadc834676/ 1.06$mu$m 150 psec laser damage study of diamond turned, diamond turned/ polished and polished metal mirrors Using a well characterized 1.06$mu$m 150 ps glass laser pulse the damage characteristics for diamond turned, diamond turned/ polished, and polished copper and silver mirrors less than 5 cm diameter were studied. Although most samples were tested with a normal angle of incidence, some were tested at 45$sup 0\$ with different linear polarization showing an increase in damage threshold for S polarization. Different damage mechanisms observed will be discussed. Laser damage is related to residual surface influences of the fabrication process. First attempts to polish diamond turned surfaces resulted in a significant decrease in laser damage threshold. The importance of including the heat of fusion in the one dimensional heat analysis of the theoretical damage threshold and how close the samples came to the theoretical damage threshold is discussed. (auth) digital.library.unt.edu/ark:/67531/metadc872232/
1.8.2.1.2 Site system engineering implementation Fiscal Year 1998 multi-year work plan
Manage the Site Systems Engineering process to provide a traceable, integrated, requirements-driven, and technically defensible baseline., Through the Site Integration Group, Systems Engineering ensures integration of technical activities across all site projects. Systems Engineering`s primary interfaces are with the Project Direction Office and with the projects, as well as with the Planning organization. digital.library.unt.edu/ark:/67531/metadc688671/
1.8.3 Site system engineering FY 1997 program plan
The FY 1997 Multi-Year Work Plan (MYWP) technical baseline describes the functions to be accomplished and the technical standards that govern the work. The following information is provided in this FY 1997 MYWP: technical baseline, work breakdown structure, schedule baseline, cost baseline, and execution year. digital.library.unt.edu/ark:/67531/metadc683550/
A 1.8 Mev K+ injector for the high current beam transport experiment fusion
For the High Current Beam Transport Experiment (HCX) at LBNL, an injector is required to deliver up to 1.8 MV of 0.6 A K{sup +} beam with an emittance of {approx}1 p-mm-mrad. We have successfully operated a 10-cm diameter surface ionization source together with an electrostatic quadrupole (ESQ) accelerator to meet these requirements. The pulse length is {approx}4 {micro}s, firing at once every 10-15 seconds. By optimizing the extraction diode and the ESQ voltages, we have obtained an output beam with good current density uniformity, except for a small increase near the beam edge. Characterization of the beam emerging from the injector included measurements of the intensity profile, beam imaging, and transverse phase space. These data along with comparison to computer simulations provide the knowledge base for designing and understanding future HCX experiments. digital.library.unt.edu/ark:/67531/metadc742178/
1.5D Quasilinear Model for Alpha Particle-TAE Interaction in ARIES ACT-I
We study the TAE interaction with alpha particle fusion products in ARIES ACT-I using the 1.5D quasilinear model. 1.5D uses linear analytic expressions for growth and damping rates of TAE modes evaluated using TRANSP pro les to calculates the relaxation of pressure pro les. NOVA- K simulations are conducted to validate the analytic dependancies of the rates, and to normalize their absolute value. The low dimensionality of the model permits calculating loss diagrams in large parameter spaces. digital.library.unt.edu/ark:/67531/metadc835197/
1/6TH SCALE STRIP EFFLUENT FEED TANK-MIXING RESULTS USING MCU SOLVENT
The purpose of this task was to determine if mixing was an issue for the entrainment and dispersion of the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) solvent in the Defense Waste Processing Facility (DWPF) Strip Effluent Feed Tank (SEFT). The MCU strip effluent stream containing the Cs removed during salt processing will be transferred to the DWPF for immobilization in HLW glass. In lab-scale DWPF chemical process cell testing, mixing of the solvent in the dilute nitric acid solution proved problematic, and the Savannah River National Laboratory (SRNL) was requested to perform scaled SEFT mixing tests to evaluate whether the problem was symptomatic of the lab-scale set-up or of the solvent. The solvent levels tested were 228 and 235 ppm, which represented levels near the estimated DWPF solvent limit of 239 ppm in 0.001M HNO{sub 3} solution. The 239 ppm limit was calculated by Norato in X-CLC-S-00141. The general approach for the mixing investigation was to: (1) Investigate the use of fluorescent dyes to aid in observing the mixing behavior. Evaluate and compare the physical properties of the fluorescent dyed MCU solvents to the baseline Oak Ridge CSSX solvent. Based on the data, use the dyed MCU solvent that best approximates the physical properties. (2) Use approximately a 1/6th linear scale of the SEFT to replicate the internal configuration for DWPF mixing. (3) Determine agitator speed(s) for scaled testing based on the DWPF SEFT mixing speed. (4) Perform mixing tests using the 1/6th SEFT and determine any mixing issues (entrainment/dispersion, accumulation, adhesion) through visual observations and by pulling samples to assess uniformity. The mixing tests used MCU solvent fabricated at SRNL blended with Risk Reactor DFSB-K43 fluorescent dye. This dyed SRNL MCU solvent had equivalent physical properties important to mixing as compared to the Oak Ridge baseline solvent, blended easily with the MCU solvent, and provided an excellent visual aid. digital.library.unt.edu/ark:/67531/metadc882799/
E-1 common analog model
1-D EQUILIBRIUM DISCRETE DIFFUSION MONTE CARLO
We present a new hybrid Monte Carlo method for 1-D equilibrium diffusion problems in which the radiation field coexists with matter in local thermodynamic equilibrium. This method, the Equilibrium Discrete Diffusion Monte Carlo (EqDDMC) method, combines Monte Carlo particles with spatially discrete diffusion solutions. We verify the EqDDMC method with computational results from three slab problems. The EqDDMC method represents an incremental step toward applying this hybrid methodology to non-equilibrium diffusion, where it could be simultaneously coupled to Monte Carlo transport. digital.library.unt.edu/ark:/67531/metadc716881/
1-D Van der Waals Foams Heated by Ion Beam Energy Deposition
One dimensional simulations of various initial average density aluminum foams (modeled as slabs of solid metal separated by low density regions) heated by volumetric energy deposition are conducted with a Lagrangian hydrodynamics code using a van der Waals equation of state (EOS). The resulting behavior is studied to facilitate the design of future warm dense matter (WDM) experiments at LBNL. In the simulations the energy deposition ranges from 10 to 30 kJ/g and from 0.075 to 4.0 ns total pulse length, resulting in temperatures from approximately 1 to 4 eV. We study peak pressures and temperatures in the foams, expansion velocity, and the phase evolution. Five relevant time scales in the problem are identified. Additionally, we present a method for characterizing the level of inhomogeneity in a foam target as it is heated and the time it takes for a foam to homogenize. digital.library.unt.edu/ark:/67531/metadc843366/
1 GeV CW nonscaling FFAG for ADS, and magnet parameters
Multi-MW proton driver capability remains a challenging, critical technology for many core HEP programs, particularly the neutrino ones such as the Muon Collider and Neutrino factory, and for high-profile energy applications such as Accelerator Driven Subcritical Reactors (ADS) and Accelerator Transmutation of Waste for nuclear power and waste management. Work is focused almost exclusively on an SRF linac, as, to date, no re-circulating accelerator can attain the 10-20 MW capability necessary for the nuclear applications. Recently, the concept of isochronous orbits has been explored and developed for nonscaling FFAGs using powerful new methodologies in FFAG accelerator design. Work is progressing on a stable, high-intensity, 1 GeV isochronous FFAG. Initial specifications of novel magnets with the nonlinear radial fields required to support isochronous operation are also reported here. digital.library.unt.edu/ark:/67531/metadc828339/
1-GeV Linac Upgrade Study at Fermilab
A linac injector for a new proton source complex at Fermilab is assumed to have a kinetic energy of 1 GeV. This linac would be sized to accelerate 100 mA of H{sup -} beam in a 200 microsecond pulse at a 15 Hz repetition rate. This would be adequate to produce {approximately}10{sup 14} protons per pulse allowing for future improvements of the new proton source complex. An alternate proposal is to add 600 MeV of side coupled cavity linac at 805 MHz to the existing 400 MeV Linac. This addition may either be in a new location or use the present Booster tunnel. A discussion of these possibilities will be given. digital.library.unt.edu/ark:/67531/metadc669837/
A 1-kW power demonstration from the advanced free electron laser
This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The main objective of this project was to engineer and procure an electron beamline compatible with the operation of a 1-kW free-electron laser (FEL). Another major task is the physics design of the electron beam line from the end of the wiggler to the electron beam dump. This task is especially difficult because electron beam is expected to have 20 kW of average power and to simultaneously have a 25% energy spread. The project goals were accomplished. The high-power electron design was completed. All of the hardware necessary for high-power operation was designed and procured. digital.library.unt.edu/ark:/67531/metadc690546/
O(1/M{sup 3}) effects for heavy-light mesons in lattice NRQCD
The masses of spin-singlet and spin-triplet S-wave mesons containing a single heavy quark are computed in the quenched approximation. The light quark action and gauge field action are both classically-improved and tadpole-improved, and the couplings to the heavy quark are organized by the 1/M expansion of tadpole-improved NRQCD. At each of two lattice spacings, near 0.22fm and 0.26fm, meson masses are obtained for heavy quarks spanning the region between charmed and bottom mesons. Results up to O(1/M), O(1/M{sup 2})and O(1/M{sup 3}) are displayed separately, so that the convergence of the heavy quark expansion can be discussed. Also, the effect of each term in the O(1/M{sup 3}) contribution is computed individually. For bottom mesons the 1/M-expansion appears to be satisfactory, but the situation for charmed mesons is less clear. digital.library.unt.edu/ark:/67531/metadc711949/
1: Mass asymmetric fission barriers for {sup 98}Mo; 2: Synthesis and characterization of actinide-specific chelating agents
Excitation functions have been measured for complex fragment emission from the compound nucleus {sup 98}Mo, produced by the reaction of {sup 86}Kr with {sup 12}C. Mass asymmetric fission barriers have been obtained by fitting the excitation functions with a transition state formalism. The extracted barriers are {approximately} 5.7 MeV higher, on average, than the calculations of the Rotating Finite Range Model (RFRM). These data clearly show an isospin dependence of the conditional barriers when compared with the extracted barriers from {sup 90}Mo and {sup 94}Mo. Eleven different liquid/liquid extractants were synthesized based upon the chelating moieties 3,2-HOPO and 3,4-HOPO; additionally, two liquid/liquid extractants based upon the 1,2-HOPO chelating moiety were obtained for extraction studies. The Pu(IV) extractions, quite surprisingly, yielded results that were very different from the Fe(III) extractions. The first trend remained the same: the 1,2-HOPOs were the best extractants, followed closely by the 3,2-HOPOs, followed by the 3,4-HOPOs; but in these Pu(IV) extractions the 3,4-HOPOs performed much better than in the Fe(III) extractions. 129 refs. digital.library.unt.edu/ark:/67531/metadc685938/
A 1 MEGAWATT POLYPHASE BOOST CONVERTER-MODULATOR FOR KLYSTRON PULSE APPLICATION
This paper describes electrical design criteria and first operational results a 140 kV, 1 MW average, 11 MW peak, zero-voltage-switching 20 kHz polyphase bridge, boost converter/modulator for klystron pulse application. The DC-DC converter derives the buss voltages from a standard 13.8 kV to 2300 Y substation cast-core transformer. Energy storage and filtering is provided by self-clearing metallized hazy polypropylene traction capacitors. Three ''H-Bridge'' Insulated Gate Bipolar Transistor (IGBT) switching networks are used to generate the polyphase 20 kHz transformer primary drive waveforms. The 20 kHz drive waveforms are chirped the appropriate duration to generate the desired klystron pulse width. PWM (pulse width modulation) of the individual 20 kHz pulses is utilized to provide regulated output waveforms with adaptive feedforward and feedback techniques. The boost transformer design utilizes amorphous nanocrystalline material that provides the required low core loss at design flux levels and switching frequencies. Resonant shunt-peaking is used on the transformer secondary to boost output voltage and resonate transformer leakage inductance. With the appropriate transformer leakage inductance and peaking capacitance, zero-voltage-switching of the IGBT's is attained, minimizing switching losses. A review of these design parameters and the first results of the performance characteristics will be presented. digital.library.unt.edu/ark:/67531/metadc720900/
A-01 metals in stormwater runoff evaluation
As a part of the A-01 investigation required by the NPDES permit, an investigation was performed to ascertain the concentrations of metals specifically copper (Cu), lead (Pb), and zinc (Zn) in stormwater being discharged through the outfall. This information would indicate whether all water being discharged would have to be treated or if only a portion of the discharged stormwater would have to be treated. A study was designed to accomplish this. The first goal was to determine if the metal concentrations increased, decreased, or remained the same as flow increased during a rain event. The second goal was to determine if the concentrations in the storm water were due to dissolved. The third goal was to obtain background data to ascertain if effluent credits could be gained due to naturally occurring metals.Samples from this study were analyzed and indicate that the copper and lead values increase as the flow increases while the zinc values remain essentially the same regardless of the flow rate. Analyses of samples for total metals, dissolved metals, TSS, and metals in solids was complicated because in all cases metals contamination was found in the filters themselves. Some conclusions can be derived if this problem is taken into account when analyzing the data. Copper concentrations in the total and dissolved fractions as well as the TSS concentrations followed the hydrograph at this outfall but the copper in solids concentration appeared to peak in the first flush and decline to nondetectable rapidly over the course of the storm event. Lead was present in the total analysis but not present in the dissolved fraction or the solids fraction of the samples. The data for zinc was interesting in that the dissolved fractions were higher than the total fraction in three out of four samples. This is probably due to the high zinc concentrations on the filters being transferred to the dissolved faction of the sample. (Abstract Truncated) digital.library.unt.edu/ark:/67531/metadc695366/
1 MeV electron irradiation of solid Xe nanoclusters in Al : an in-situ HRTEM study.
Thin film samples of a simple embedded nanocluster system consisting of solid Xe precipitates in Al have been subjected to 1 MeV electron irradiation in a high-voltage electron microscope. High-resolution images have been recorded on videotape in order to monitor the changes to the system resulting from the passage of electrons through the film. Inspection of the video recordings (in some cases frame-by-frame) reveals that complex, rapid processes occur under the electron beam. These include, movement of small clusters, coalescence of neighboring clusters, shape changes, the apparent melting and resolidification of the Xe, and the creation and annealing of extended defects within the Xe lattice. A tentative interpretation of some of the observations is presented in terms of the electron-induced displacement processes at the surface of the clusters. digital.library.unt.edu/ark:/67531/metadc738815/
1 mil gold bond wire study.
In microcircuit fabrication, the diameter and length of a bond wire have been shown to both affect the current versus fusing time ratio of a bond wire as well as the gap length of the fused wire. This study investigated the impact of current level on the time-to-open and gap length of 1 mil by 60 mil gold bond wires. During the experiments, constant current was provided for a control set of bond wires for 250ms, 410ms and until the wire fused; non-destructively pull-tested wires for 250ms; and notched wires. The key findings were that as the current increases, the gap length increases and 73% of the bond wires will fuse at 1.8A, and 100% of the wires fuse at 1.9A within 60ms. Due to the limited scope of experiments and limited data analyzed, further investigation is encouraged to confirm these observations. digital.library.unt.edu/ark:/67531/metadc827545/
1+-n+ ECR ION SOURCE DEVELOPMENT TEST STAND
A test stand for the investigation of 1+-n+ charge boosting using an ECR ion sources is currently being assembled at the Texas A&M Cyclotron Institute. The ultimate goal is to relate the charge-boosting of ions of stable species to possible charge-boosting of ions of radioactive species extracted from the diverse, low-charge-state ion sources developed for radioactive ion beams. digital.library.unt.edu/ark:/67531/metadc878317/
1 nA beam position monitoring system
A system has been developed at Jefferson Lab for measuring transverse position of very low current beams delivered to the Experimental Hall B of the Continuous Electron Beam Accelerator Facility (CEBAF). At the heart of the system is a position sensitive cavity operating at 1497 MHz. The cavity utilizes a unique design which achieves a high sensitivity to beam position at a relatively low cavity Q. The cavity output RF signal is processed using a down-converter and a commercial lock-in amplifier operating at 100 kHz. The system interfaces with a VME based EPICS control system using the IEEE, 488 bus. The main features of the system are simple and robust design, and wide dynamic range capable of handling beam currents from 1 nA to 1000 nA with an expected resolution better than 100 {mu}m. This paper outlines the design of the system. digital.library.unt.edu/ark:/67531/metadc675723/
1 Outreach, Education and Domestic Market Enhancement 2 Export Promotion and Assistance
Geothermal Energy Association supports the US geothermal industry in its efforts to bring more clean geothermal energy on-line throughout the world. Activities designed to accomplish this goal include: (1) developing and maintaining data bases, web pages, (2) commissioning of special studies and reports, (3) preparing, printing and distributing brochures and newsletters, (4) developing exhibits and displays, and participating in trade shows, (5) designing, producing and disseminating audio-video materials, (6) monitoring and coordinating programs carried out by US DOE and other Federal agencies, (7) holding workshops to facilitate communication between researchers and industry and to encourage their recognition of emerging markets for geothermal technology, (8) attending conferences, making speeches and presentation, and otherwise interacting with environmental and other renewable energy organizations and coalitions, (9) hosting events in Washington, DC and other appropriate locations to educate Federal, State and local representatives, environmental groups, the news media, and other about the status and potential of geothermal energy, (10) conducting member services such as the preparation and distribution of a member newsletter related to operating and maintaining s useful and viable association, and (11) performing similar kinds of activities designed to inform others about geothermal energy. The activities of the export promotion aim to assist industry in accomplishing the goal of successfully penetrating and developing energy in country with existing geothermal resources and a desire to develop them. Activities including in export promotion are: (1)needs analysis and assessment involve monitoring the progress of developing markets and projects overseas and working with US industry to determine what future activities by GEA would be of greatest assistance, (2) outreach includes the preparation and dissemination of brochures and videos for foreign professionals, officials and decision-makers as well as presentations of information of the geothermal technology and the capabilities of the US geothermal industry, (3) Market conditioning involves first, evaluating the market and challenges for conducting business successfully in a country followed by appropriate training or technical assistance, (4) Market developing includes activities conducted to assist industry in developing the market for sales of services and technology, including direct and reverse trade missions, support for industry to participate in conferences overseas to sell goods and services, and other activities. digital.library.unt.edu/ark:/67531/metadc783392/
A 1- to 5-MW, RCS-based, short-pulse spallation neutron source
Two accelerator configurations, the linac/compressor ring scheme and the linac/RCS scheme, are commonly used to provide the proton beam power for a short-pulse spallation neutron source. In one configuration, a full-power linac provides the beam power and a compressor ring shortens the pulse length from 1-ms down to 1 {micro}s. In the other, rapid cycling synchrotrons (RCSs) provide the beam power and also shorten the pulse length. A feasibility study of a staged approach to a 5-MW proton source utilizing RCS technology, allowing intermediate operation at 1 MW, was performed at ANL and is presented in this paper. This study is complementary to a study in progress at ORNL based on a linac and an accumulator ring. The 1-MW facility consists of a 400-MeV injector linac that delivers 0.5-mA time-averaged current, a synchrotron that accelerates the beam to 2 GeV at a 30-Hz rate, and two neutron-generating target stations. In the second phase, the 2-GeV beam is accelerated to 10 GeV by a larger RCS, increasing the facility beam power to 5 MW. digital.library.unt.edu/ark:/67531/metadc680327/
1-watt composite-slab Er:YAG laser. Revision 1
A diode-side-pumped discrete-optic Er{sup 3+} :YAG laser employs pump-light coupling through a sapphire plate diffusion-bonded to the laser slab, removing heat directly at the pump face of the slab instead of requiring conduction through to its far side. This lowers the temperature in the gain region and gives reduced thermal lensing, which produces exceptional beam quality (M{sup 2} {approx} 1.3) at output powers {approx} 0.3 Watt. Powers above 1 Watt have been demonstrated with peak slope efficiencies {approx}20%. The novel architecture is also applicable to other side-pumped lasers. digital.library.unt.edu/ark:/67531/metadc696997/
2-1/2-D electromagnetic modeling of nodular defects in high-power multilayer optical coatings
Advances in the design and production of high damage threshold optical coatings for use in mirrors and polarizers have been driven by the design requirements of high-power laser systems such as the proposed 1.8-MJ National Ignition Facility (NIF) and the prototype 12- kJ Beamlet laser system. The present design of the NIF will include 192 polarizers and more than 1100 mirrors. Currently, the material system of choice for high-power multilayer optical coatings with high damage threshold applications near 1.06 {mu}m are e-beam deposited HfO{sub 2}/Si0{sub 2} coatings. However, the optical performance and laser damage thresholds of these coatings are limited by micron-scale defects and insufficient control over layer thickness. In this report, we will discuss the results of our 2-1/2-D finite-element time- domain (FDTD) EM modeling effort for rotationally-symmetric nodular defects in multilayer dielectric HR coatings. We have added a new diagnostic to the 2-1/2-D FDTD EM code, AMOS, that enables us to calculate the peak steady-state electric fields throughout a 2-D planar region containing a 2-D r-z cross-section of the axisymmetric nodular defect and surrounding multilayer dielectric stack. We have also generated a series of design curves to identify the range of loss tangents for Si0{sub 2} and HfO{sub 2} consistent with the experimentally determined power loss of the HR coatings. In addition, we have developed several methods to provide coupling between the EM results and the thermal-mechanical simulation effort. digital.library.unt.edu/ark:/67531/metadc684881/
2.1 Pan-WCRP Monsoon Modelling Workshop Summary
Ken Sperber led a discussion of the outcome of the Pan-WCRP Monsoon Modelling Workshop that was held at the University of California at Irvine from 15-17 June 2005. At the workshop presentations from key CLIVAR and GEWEX panels were presented to highlight the outstanding problems in modelling the Earth's monsoons. Additionally, presentations from invited experts were given to highlight important aspects of monsoon phenomena and processes, such as low-level jets, air-sea interaction, predictability, observational networks/studies, and model test beds etc. Since all persons attending the CLIVAR AAMP meeting were present for all, or most, of the monsoon workshop, a detailed description of the workshop presentations was not given. Rather, the discussion was focused on the recommendations of the workshop breakout groups and their relevance to CLIVAR AAMP. CLIVAR AAMP endorsed the near-term workshop recommendation of investigating the diurnal cycle using a hierarchy of models a key way forward for promoting CLIVAR/GEWEX interactions. In GCM studies CLIVAR researchers have identified the diurnal cycle as a forced ''mode'' of variability that is poorly represented in terms of amplitude and phase, especially in the case of precipitation. Typical phase errors of 6-12 hours are noted over both land and ocean in GCMs. CLIVAR views adequate simulation of the diurnal cycle as key aspect of variability in its own right, but also because of its potential rectification on to subseasonal variability (e.g., the Madden-Julian oscillation). It is hypothesized that improvement of diurnal variability may lead to an improved representation of intraseasonal variability and improved skill of monsoon forecasts on medium-range to seasonal time scales. digital.library.unt.edu/ark:/67531/metadc875709/