Search Results

0-2 kv Flash Tube Supplies

Description: The power supplies designed and constructed to power high-intensity flash tubes are described. Three supplies, capable of charging 100 mfd to 2 kv with a repetltion rate of not less than 0.8 sec, are operated remotely from a control panel containing 3 powerstats. The power supplies are full wave center trapped rectifiers employing silicon rectifiers. (M.C.G.)
Date: March 15, 1962
Creator: Miller, D. M.

0. 4 mm interferometer system using dielectric waveguide

Description: A 0.4 mm submillimeter-wave, phase-modulated polarimeter/interferometer is used for simultaneous time-dependent measurement of line-averaged electron density and poloidal field-induced Faraday rotation along chords of the plasma column in ISX-B tokamak. Heterodyna detection and hollow dielectric waveguide are utilized to achieve the high sensitivity required for the multichord equipment.
Date: January 1, 1982
Creator: Hutchinson, D. P.; Ma, C. H.; Staats, P. A. & Vander Sluis, K. L.

0.5 μm E/D AlGaAs/GaAs heterostructure field effect transistor technology with DFET threshold adjust implant

Description: 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.
Date: April 1997
Creator: Baca, A. G.; Sherwin, M. E.; Zolper, J. C.; Shul, R. J.; Briggs, R. D.; Heise, J. A. et al.

A 0. 5 to 3. 0 MeV monoenergetic positron beam

Description: An adjustable, 0.5--3 MeV monoenergetic positron beam has been constructed at Brookhaven. Currently a /sup 22/Na source with a W(100) foil transmission moderator produces a 1.1 mm FWHN beam with an intensity of 3/times/10/sup 5/ e/sup +//sec at a target located downstream from the accelerator. The divergence of the beam is less than 0.1/degree/ at 2.2 MeV energy. A SOA gun with 2 lens transport system brings the beam to a focus at the entrance of an electrostatic 3 MeV Dynamitron accelerator. The post acceleration beam transport system comprises 3 focusing solenolds, 4 sets of steering magnets and a 90/degree/ double focusing bending magnet. The beam energy spread at the target is <1 keV FWHN deduced from the beam size. Below we describe the positron extraction optics and acceleration, the construction of the beamline and the beam diagnostic devices. The salient beam parameters are listed at the end of this paper. 2 refs., 3 figs., 1 tab.
Date: 1988~
Creator: Huomo, H.; AsokaKumar, P.; Henderson, S. D.; Phlips, B. F.; Mayer, R.; McDonough, J. et al.

0.7-eV GaInAs Junction for a GaInP/GaAs/GaInAs(1-eV)/GaInAs(0.7-eV) Four-Junction Solar Cell: Preprint

Description: 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.
Date: May 1, 2006
Creator: Friedman, D. J.; Geisz, J. F.; Norman, A. G.; Wanlass, M. W. & Kurtz, S. R.

0. 9 a Gev /sup 238/U on /sup 238/U collisions in the LBL streamer chamber. Appendix A

Description: Charged particle exclusive data for high multiplicity U on U events are reported. Analyses are based on comparison with Cugnon's intranuclear cascade model, and the explosion-evaporation simulation of Fai and Randrup. The azimuthal structure of the observed events shows evidence of collective flow. The widely used flow angle methodology proves to be relatively insensitive to collective effects under the conditions of the present experiment. An isotropic pattern of ejectile emission is not reached at maximum multiplicity. 18 refs., 4 figs.
Date: January 1, 1984
Creator: Fung, S.Y.; Beavis, D.; Gorn, W.; Keane, D.; Liu, Y.M.; Poe, R.T. et al.

0. 20-m (8-in.) Primary Burner Development Report

Description: High-Temperature Gas-Cooled Reactors (HTGRs) utilize graphite-base fuels. Fluidized-bed burners are being employed successfully in the experimental reprocessing of these fuels. The primary fluidized-bed burner is a unit operation in the reprocessing flowsheet in which the graphite moderator is removed. A detailed description of the development status of the 0.20-m (8-in.) diameter primary fluidized-bed burner as of July 1, 1977 is presented. Experimental work to date performed in 0.10; 0.20; and 0.40-m (4, 8, and 16 in.) diameter primary burners has demonstrated the feasibility of the primary burning process and, at the same time, has defined more clearly the areas in which additional experimental work is required. The design and recent operating history of the 0.20-m-diameter burner are discussed, with emphasis placed upon the evolution of the current design and operating philosophy.
Date: December 1977
Creator: Stula, R. T.; Young, D. T. & Rode, J. S.

0.351 micron Laser Beam propagation in High-temperature Plasmas

Description: 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 ...
Date: December 10, 2007
Creator: Froula, D.; Divol, L.; Meezan, N.; Ross, J.; Berger, R. L.; Michel, P. et al.

0.25mm-Thick CCD Packaging for the Dark Energy Survey Camera Array

Description: Abstract: 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.
Date: 2006-06~
Creator: Derylo, Greg; Diehl, H. Thomas & Estrada, Juan

0.52eV Quaternary InGaAsSb Thermophotovoltaic Diode Technology

Description: 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.
Date: June 9, 2004
Creator: Dashiell, M. W.; Beausang, J. F.; Nichols, G.; Depoy, D. M.; Danielson, L. R.; Ehsani, H. et al.

T = 0 AND T = 1 PAIRING IN LIGHT NUCLEI.

Description: No Description Available.
Date: January 1, 1969
Creator: Goodman, A. L.

$D^0 \bar{D}^0$ Mixing at BaBar

Description: 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.
Date: October 26, 2011
Creator: Coleman, Jonathon

0-D study of the compression of low temperature spheromaks

Description: Compression of low temperature spheromak plasmas has been studied with the aid of a O-D two-fluid computer code. It is found that in a plasma which is radiation dominated, the electron temperature can be increased by up to a factor of seven for a compression of a factor of two, provided the temperature is above some critical value (approx.25eV) and the electron density particle confinement time product n/sub e/tau/sub p/ greater than or equal to 1 x 10/sup 9/s/cm/sup 3/. If the energy balance is dominated by particle confinement losses rather than radiation losses, the effect of compression is to raise the temperature as T/sub e/ approx.C/sup 6/5/, for constant tau/sub p/.
Date: September 1, 1985
Creator: Meyerhofer, D.D.; Hulse, R.A. & Zweibel, E.G.

D-0 End Calorimeter Warm Tube/TeV Dry Air Purge

Description: 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.
Date: August 14, 1991
Creator: Leibfritz, J. R.

0-G experiments with advanced ceramic fabric wick structures

Description: Both Air Force and NASA future spacecraft thermal management needs span the temperature range from cryogenic to liquid metals. Many of these needs are changing and not well defined and will remain so until goals, technology, and missions converge. Nevertheless, it is certain that high-temperature (> 800 K) and medium-temperature (about 450 K) radiator systems will have to be developed that offer significant improvements over current designs. This paper discusses experiments performed in the lower temperature regime as part of a comprehensive advanced ceramic fabric (ACF) heat pipe development program. These experiments encompassed wicking tests with various ceramic fabric samples, and heat transfer tests with a 1-m long prototype ACF water heat pipe. A prototype ceramic fabric/titanium water heat pipe has been constructed and tested; it transported up to 60 W of power at about 390 K. Startup and operation both with and against gravity examined. Wick testing was begun to aid in the design and construction of an improved prototype heat pipe, with a 38-{mu}m stainless steel linear covered by a biaxially-braided Nextel (trademark of the 3M Co., St. Paul, Minnesota) sleeve that is approximately 300-{mu}m thick. Wick testing took place in 1-g; limited testing in 0-g was initiated, and results to date suggest that in 0-g, wick performance improves over that in 1-g.
Date: July 1991
Creator: Antoniak, Z.I.; Webb, B.J.; Bates, J.M.; Cooper, M.F. & Pauley, K.A.

D-0 North End Cap Calorimeter Cold Test Results

Description: 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 ...
Date: August 2, 1990
Creator: Michael, J.

D-0 South End Cap Calorimeter Cold Test Results

Description: 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 ...
Date: November 26, 1990
Creator: Rucinski, R.

The 0/sup +/ /minus/ 1/sup +/ A = 4. lambda. -hypernuclei binding energy difference in an exact equation, separable potential calculation

Description: None
Date: January 1, 1988
Creator: Gibson, B.F. & Lehman, D.R.

0/sup -/ to 0/sup +/ beta decay in A = 16

Description: Techniques and results of the measurement of the beta-decay rate of the first excited state of /sup 16/N to the ground state of /sup 16/O are reported. Energy levels involved in the decay are shown, and the /sup 16/N 0/sup -/ beta decay branching ration is given. (WHK)
Date: January 1, 1982
Creator: Gagliardi, C.; Garvey, G.T.; Wrobel, J.R. & Freedman, S.J.

1-1/2-loop semiscale isothermal test program: program and system description in support of experiment data reports

Description: No Description Available.
Date: February 1, 1974
Creator: Naff, S.A. & Pinson, P.A.

1.1-meter bore, 8-Tesla test facility

Description: 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)
Date: November 19, 1975
Creator: Nelson, R.; Cornish, D.; Zbasnik, J.; Sackett, S. & Taylor, C.

1.1 Simulations of a Free-Electron Laser Oscillator at Jefferson Lab Lasing in the Vacuum Ultraviolet

Description: 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.
Date: April 1, 2013
Creator: Shinn, Michelle D. & Benson, Stephen V.

1/2 Creep Fracture in Ceramic Polycrystals I. Creep Cavitation Effects in Polycrystalline Alumina

Description: 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,
Date: September 1980
Creator: Porter, J. R.; Blumenthal, W. & Evans, A. G.

1. 2-GeV damping-ring complex for the Stanford Linear Collider

Description: The choice of parameters, the design, a 2-1/2 year consruction program and the early operation of a high field, high tune research and development damping ring complex for one of the two linear collider beams are described.
Date: July 1983
Creator: Fischer, G. E.; Davies-White, W.; Fieguth, T. & Wiedemann, H.