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3,675,007 Matching Results

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(open access)

0-2 kv Flash Tube Supplies

In order to perform the various experiments with a bubble chamber, a high intensity flash tube is used. This report briefly describes the power supplies designed and constructed to power these lamps.

Date: March 15, 1962

Creator: Miller, D. M.

Object Type: Report

System: The UNT Digital Library

(open access)

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.

Object Type: Report

System: The UNT Digital Library

AL 00-3

This abstract painting is mostly black with some white vertical scrapes.

Date: 2000

Creator: Falsetta, Vincent

Object Type: Artwork

System: The UNT Digital Library

(open access)

A 0. 4 mm Interferometer System Using Dielectric Waveguide

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.

Object Type: Article

System: The UNT Digital Library

(open access)

0.5 μm 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.

Date: April 1997

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

Object Type: Article

System: The UNT Digital Library

(open access)

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

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.

Object Type: Article

System: The UNT Digital Library

(open access)

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.

Date: May 1, 2006

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

Object Type: Article

System: The UNT Digital Library

(open access)

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

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.

Object Type: Article

System: The UNT Digital Library

(open access)

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

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.

Object Type: Report

System: The UNT Digital Library

(open access)

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.

Date: May 31, 2001

Creator: Keith, Robert

Object Type: Report

System: The UNT Digital Library

(open access)

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.

Date: February 25, 2000

Creator: Keith, Robert

Object Type: Report

System: The UNT Digital Library

(open access)

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 < 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 < 5 x …

Date: December 10, 2007

Creator: Froula, D.; Divol, L.; Meezan, N.; Ross, J.; Berger, R. L.; Michel, P. et al.

Object Type: Report

System: The UNT Digital Library

(open access)

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

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

Object Type: Article

System: The UNT Digital Library

(open access)

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.

Date: June 9, 2004

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

Object Type: Report

System: The UNT Digital Library

(open access)

T = 0 and T = 1 Pairing in Light Nuclei.

None

Date: January 1, 1969

Creator: Goodman, A. L.

Object Type: Thesis or Dissertation

System: The UNT Digital Library

$$D^0 \bar{D}^0$ Mixing at BaBar$ (open access)

$D^0 \bar{D}^0$ 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.

Date: October 26, 2011

Creator: Coleman, Jonathon

Object Type: Article

System: The UNT Digital Library

(open access)

0-D study of the compression of low temperature spheromaks

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.

Object Type: Report

System: The UNT Digital Library

(open access)

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 …

Date: August 14, 1991

Creator: Leibfritz, J. R.

Object Type: Report

System: The UNT Digital Library

(open access)

0-G experiments with advanced ceramic fabric wick structures

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, …

Date: July 1991

Creator: Antoniak, Z. I.; Webb, B. J.; Bates, J. M.; Cooper, M. F. & Pauley, K. A.

Object Type: Article

System: The UNT Digital Library

(open access)

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 …

Date: August 2, 1990

Creator: Michael, J.

Object Type: Report

System: The UNT Digital Library

00 Ranch (Daube) near Mannsville, Ok.

00 Ranch (Daube) near Mannsville, Ok. Two cowboys and a herd of cattle next to a barn with the 00 sign. The name of Charles Mobly is on the back of the post card.

Date: unknown

Creator: unknown

Object Type: Photograph

System: The Gateway to Oklahoma History

(open access)

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 …

Date: November 26, 1990

Creator: Rucinski, R.

Object Type: Report

System: The UNT Digital Library

(open access)

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

None

Date: January 1, 1988

Creator: Gibson, B. F. & Lehman, D. R.

Object Type: Article

System: The UNT Digital Library

(open access)

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

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.

Object Type: Article

System: The UNT Digital Library

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