Partner
UNT Libraries Government Documents Department
3,247
UNT Libraries Special Collections
512
Oklahoma Historical Society
466
UNT Libraries
226
Sterling Municipal Library
118
National Museum of the Pacific War/Admiral Nimitz Foundation
113
San Antonio Public Library
63
Carl Albert Congressional Research and Studies Center
50
Patrick Heath Public Library
31
Livingston Municipal Library
30
88 More
Collection
Office of Scientific & Technical Information Technical Reports
1,590
Texas Digital Newspaper Program
1,166
Congressional Research Service Reports
882
Oklahoma Digital Newspaper Program
532
Tocker Foundation Grant
524
Defense Base Closure and Realignment Commission
369
Government Accountability Office Reports
288
University Photography Collection
197
Photographing UNT
197
The Greensheet
148
153 More
Degree Department
Degree Discipline
Degree Level
Country
States
Decade
Month
Day
Language
5,743 Matching Results
Results open in a new window/tab.
Results:
1 - 24 of
5,743
next
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
1-10 Mbar Laser-Driven Shocks Using the Janus Laser Facility
We report preliminary results using the Lawrence Livermore National Laboratory (LLNL) Janus laser facility to generate high pressure laser-driven shocks in the 1-10 Mbar regime. These experiments address various issues, including shock steadiness, planarity, uniformity and low target preheat, important for making precision EOS measurements on a small (E < 250 J) laser facility. A brief description of the experimental techniques, target design and measurements will be given.
Date:
August 10, 2001
Creator:
Dunn, J.; Price, D. F.; Moon, S. J.; Cauble, R. C.; Springer, P. T. & Ng, A.
Object Type:
Article
System:
The UNT Digital Library
2-MV electrostatic quadrupole injector for heavy-ion fusion
High current and low emittance are principal requirements for heavy-ion injection into a linac driver for inertial fusion energy. An electrostatic quadrupole (ESQ) injector is capable of providing these high charge density and low emittance beams. We have modified the existing 2-MV Injector to reduce beam emittance and to double the pulse length. We characterize the beam delivered by the modified injector to the High Current Transport Experiment (HCX) and the effects of finite rise time of the extraction voltage pulse in the diode on the beam head. We demonstrate techniques for mitigating aberrations and reducing beam emittance growth in the injector.
Date:
November 10, 2004
Creator:
Bieniosek, F. M.; Celata, C. M.; Henestroza, E.; Kwan, J. W.; Prost, L. & Seidl, P. A.
Object Type:
Article
System:
The UNT Digital Library
3-D Force-balanced Magnetospheric Configurations
The knowledge of plasma pressure is essential for many physics applications in the magnetosphere, such as computing magnetospheric currents and deriving magnetosphere-ionosphere coupling. A thorough knowledge of the 3-D pressure distribution has however eluded the community, as most in-situ pressure observations are either in the ionosphere or the equatorial region of the magnetosphere. With the assumption of pressure isotropy there have been attempts to obtain the pressure at different locations by either (a) mapping observed data (e.g., in the ionosphere) along the field lines of an empirical magnetospheric field model or (b) computing a pressure profile in the equatorial plane (in 2-D) or along the Sun-Earth axis (in 1-D) that is in force balance with the magnetic stresses of an empirical model. However, the pressure distributions obtained through these methods are not in force balance with the empirical magnetic field at all locations. In order to find a global 3-D plasma pressure distribution in force balance with the magnetospheric magnetic field, we have developed the MAG-3D code, that solves the 3-D force balance equation J x B = (upside-down delta) P computationally. Our calculation is performed in a flux coordinate system in which the magnetic field is expressed in terms …
Date:
February 10, 2003
Creator:
Zaharia, Sorin; Cheng, C. Z. & Maezawa, K.
Object Type:
Report
System:
The UNT Digital Library
A 3-year plan for beam science in the heavy-ion fusion virtual national laboratory
In December 1998, LBNL Director Charles Shank and LLNL Director Bruce Tarter signed a Memorandum of Agreement to create the Heavy-Ion Fusion Virtual National Laboratory (HIF-VNL) with the purpose of improving the efficiency and productivity of heavy ion research through coordination of the two laboratories' efforts under one technical director. In 1999, PPPL Director Robert Goldston signed the VNL MOA for PPPL's heavy-ion fusion group to join the VNL. LBNL and LLNL each contribute about 45% of the $10.6 M/yr trilab VNL effort, and PPPL contributes currently about 10% of the VNL effort. The three labs carry out collaborative experiments, theory and simulations of a variety of intense beam scientific issues described below. The tri-lab HIF VNL program is part of the DOE Office of Fusion Energy Sciences (OFES) fusion program. A short description of the four major tasks areas of HIF-VNL research is given in the next section. The task areas are: High Current Experiment, Final Focus/Chamber Transport, Source/Injector/Low Energy Beam Transport (LEBT), and Theory/Simulation. As a result of the internal review, more detailed reviews of the designs, costs and schedules for some of the tasks have been completed, which will provide more precision in the scheduled completion dates …
Date:
September 10, 2001
Creator:
Logan, B. Grant
Object Type:
Report
System:
The UNT Digital Library
[5 Days Left To Enter TDNA Awards Contest]
A notice from the Texas Daily Newspaper Associations, which states that the deadline to enter the TDNA Awards is in five days, a January 15 deadline. The document requests that TDNA members pass the notice along to publishers, editors, copy editors, sportswriters, marketing and promotion staff who have worked hard to promote their newspapers to the community that the deadline is soon. The document also details the type of awards that are available. Winners will receive awards at the 2006 TDNA Annual Meeting on Monday, March 20, 2006 at the Renaissance Worthington Hotel in Fort Worth.
Date:
January 10, 2008
Creator:
Texas Daily Newspaper Association
Object Type:
Text
System:
The UNT Digital Library
The 10,000 Year Plan
Pallavi Pharkya thinks a lot about the future. Pharkya, a Ph.D. candidate in materials science and engineering, works in the area of corrosion science, predicting how materials will perform over extended periods of time. Her particular focus is a nickel-chromium-molybdenum alloy called C-22, a highly corrosion-resistant metal. Pharkya's aim is to help determine whether containers made from C-22 can be used to store high-energy nuclear waste--for 10,000 years and longer. Pharkya's work is part of a plan by the U.S. Department of Energy to consolidate the country's nuclear waste in a single proposed repository. The proposed repository is in Yucca Mountain located in a remote Nevada desert. Currently about 70,000 metric tons of spent nuclear fuel and high-level radioactive waste are divided between approximately 100 sites around the country. The undertaking, Pharkya emphasizes, is massive. To study just the corrosion aspects of the packaging, Case is collaborating with eight other universities, five national labs and Atomic Energy of Canada Limited. Even with so many players, the study will likely take several years to complete. Heading the entire group is Joe Payer, a professor of materials science and engineering at Case and Pharkya's mentor. ''I came here to have the opportunity …
Date:
February 10, 2006
Creator:
Srisaro, L.
Object Type:
Article
System:
The UNT Digital Library
THE 10,000 YEAR PLAN
Pharkya, a Ph.D. candidate in materials science and engineering, works in the area of corrosion science, predicting how materials will perform over extended periods of time. Her particular focus is a nickel-chromium-molybdenum alloy called C-22, a highly corrosion-resistant metal. Pharkya's aim is to help determine whether containers made from C-22 can be used to store high-energy nuclear waste--for 10,000 years and longer. Pharkya's work is part of a plan by the U.S. Department of Energy to consolidate the country's nuclear waste in a single proposed repository. The proposed repository is in Yucca Mountain located in a remote Nevada desert. Currently about 70,000 metric tons of spent nuclear fuel and high-level radioactive waste are divided between approximately 100 sites around the country. The undertaking, Pharkya emphasizes, is massive. To study just the corrosion aspects of the packaging, Case is collaborating with eight other universities, five national labs and Atomic Energy of Canada Limited. Even with so many players, the study will likely take several years to complete. Heading the entire group is Joe Payer, a professor of materials science and engineering at Case and Pharkya's mentor. ''I came here to have the opportunity to work with Dr. Payer, an expert in …
Date:
February 10, 2006
Creator:
Srisuro, L.
Object Type:
Article
System:
The UNT Digital Library
14-MeV Neutron Generator Used as a Thermal Neutron Source
One of the most important applications of the general purpose Monte Carlo N-Particle (MCNPS and MCNPX) codes is neutron shielding design. We employed this method to simulate the shield of a 14-MeV neutron generator used as a thermal neutron source providing an external thermal neutron beam for testing large area neutron detectors developed for diffraction studies in biology and also useful for national security applications. Nuclear reactors have been the main sources of neutrons used for scientific applications. In the past decade, however, a large number of reactors have been shut down, and the importance of other, smaller devices capable of providing neutrons for research has increased. At Brookhaven National Laboratory a moderated Am-Be neutron source with shielding is used for neutron detector testing. This source is relatively weak, but provides a constant flux of neutrons, even when not in use. The use of a 14 MeV energized neutron generator, with an order of magnitude higher neutron flux has been considered to replace the Am-Be source, but the higher fast neutron yield requires a more careful design of moderator and shielding. In the present paper we describe a proposed shielding configuration based on Monte Carlo calculations, and provide calculated neutron …
Date:
August 10, 2008
Creator:
Dioszegi, I.
Object Type:
Article
System:
The UNT Digital Library
AZ-101 Mixer Pump Test Qualification Test Procedures (QTP)
Describes the Qualification test procedure for the AZ-101 Mixer Pump Data Acquisition System (DAS). The purpose of this Qualification Test Procedure (QTP) is to confirm that the AZ-101 Mixer Pump System has been properly programmed and hardware configured correctly. This QTP will test the software setpoints for the alarms and also check the wiring configuration from the SIMcart to the HMI. An Acceptance Test Procedure (ATP), similar to this QTP will be performed to test field devices and connections from the field.
Date:
January 10, 2000
Creator:
Thomas, W. K.
Object Type:
Report
System:
The UNT Digital Library
501(c)(3) Hospitals and the Community Benefit Standard
This report examines the standard under which hospitals qualify for tax-exempt charitable status under federal law, recent inquiries made by Congress and the IRS into whether hospitals are conducting sufficient activities to justify their exemption, and section 6007 of S. 1796.
Date:
November 10, 2009
Creator:
Lunder, Erika K. & Liu, Edward C.
Object Type:
Report
System:
The UNT Digital Library
805 MHz and 201 MHz RF cavity development for MUCOOL
A muon cooling channel calls for very high acceleratinggradient RF structures to restore the energy lost by muons in theabsorbers. The RF structures have to be operated in a strong magneticfield and thus the use of superconducting RF cavities is excluded. Toachieve a high shunt impedance while maintaining a large enough apertureto accommodate a large transverse emittance muon beam, the cavity designadopted is a pillbox-like geometry with thin Be foils to terminate theelectromagnetic field at the cavity iris. The possibility of using gridsof thin-walled metallic tubes for the termination is also being explored.Many of the RF-related issues for muon cooling channels are being studiedboth theoretically and experimentally using an 805 MHz cavity that has apillbox-like geometry with thin Be windows to terminate the cavityaperture. The design and performance of this cavity are reported here.High-power RF tests of the 805 MHz cavity are in progress at Lab G inFermilab. The cavity has exceeded its design gradient of 30 MV/m,reaching 34 MV/m without external magnetic field. No surface damage wasobserved at this gradient. The cavity is currently under conditioning atLab G with an external magnetic field of 2.5 T. We also present here a201 MHz cavity design for muoncooling channels. The proposed …
Date:
October 10, 2002
Creator:
DLi@lbl.gov
Object Type:
Article
System:
The UNT Digital Library
900-24 Mock Tensile Tests
None
Date:
December 10, 2007
Creator:
Cunningham, B J & Gagliardi, F J
Object Type:
Report
System:
The UNT Digital Library
1400, +/- 900V PEAK PULSE SWITCH MODE POWER SUPPLIES FOR SNS INJECTION KICKERS.
This paper describes simulation and experimental results for a 1400A, {+-} 900V peak rated, switch mode power supply for SNS Injection Kicker Magnets. For each magnet (13 m{Omega}, 160{micro}H), the power supply must supply controlled pulses at 60 Hz repetition rate. The pulse current must rise from zero to maximum in less than 1 millisec in a controlled manner, flat top for up to 2 millisec, and should fall in a controlled manner to less than 4A within 500{micro}s. The low current performance during fall time is the biggest challenge in this power supply. The simulation results show that to meet the controlled fall of the current and the current ripple requirements, voltage loop bandwidth of at least 10 kHz and switching frequency of at least 100 kHz are required. To achieve high power high frequency switching with IGBT switches, a series connected topology with three phase shifted (O{sup o}, 60{sup o} & 120{sup o}) converters each with 40 kHz switching frequency (IGBT at 20kHz), has been achieved. In this paper, the circuit topology, relevant system specifications and experimental results that meet the requirements of the power supply are described in detail. A unique six pulse SCR rectifier circuit with …
Date:
March 10, 2004
Creator:
LAMBIASE,R. ENG,W. SANDBERG,J. DEWAN,S. HOLMES,R. RUST,K. ZENG,J.
Object Type:
Article
System:
The UNT Digital Library
15th Street News (Midwest City, Okla.), Vol. 29, No. 20, Ed. 1 Friday, March 10, 2000
Newspaper from Rose State College in Midwest City, Oklahoma that includes national, local, and campus news along with advertising.
Date:
March 10, 2000
Creator:
Steele, Janet
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
15th Street News (Midwest City, Okla.), Vol. 30, No. 9, Ed. 1 Friday, November 10, 2000
Newspaper from Rose State College in Midwest City, Oklahoma that includes national, local, and campus news along with advertising.
Date:
November 10, 2000
Creator:
Pace, Joshua
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
15th Street News (Midwest City, Okla.), Vol. 31, No. 28, Ed. 1 Friday, May 10, 2002
Newspaper from Rose State College in Midwest City, Oklahoma that includes national, local, and campus news along with advertising.
Date:
May 10, 2002
Creator:
Baldwin, Alisha
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
15th Street News (Midwest City, Okla.), Vol. 33, No. 6, Ed. 1 Friday, October 10, 2003
Newspaper from Rose State College in Midwest City, Oklahoma that includes national, local, and campus news along with advertising.
Date:
October 10, 2003
Creator:
Hadley, Meghann
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
15th Street News (Midwest City, Okla.), Vol. 35, No. 18, Ed. 1 Friday, February 10, 2006
Newspaper from Rose State College in Midwest City, Oklahoma that includes national, local, and campus news along with advertising.
Date:
February 10, 2006
Creator:
Waltman, Erin
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
15th Street News (Midwest City, Okla.), Vol. 35, No. 22, Ed. 1 Friday, March 10, 2006
Newspaper from Rose State College in Midwest City, Oklahoma that includes national, local, and campus news along with advertising.
Date:
March 10, 2006
Creator:
Waltman, Erin
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
15th Street News (Midwest City, Okla.), Vol. 36, No. 10, Ed. 1 Friday, November 10, 2006
Newspaper from Rose State College in Midwest City, Oklahoma that includes national, local, and campus news along with advertising.
Date:
November 10, 2006
Creator:
Ray, Johnna
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
15th Street News (Midwest City, Okla.), Vol. 38, No. 7, Ed. 1 Friday, October 10, 2008
Newspaper from Rose State College in Midwest City, Oklahoma that includes national, local, and campus news along with advertising.
Date:
October 10, 2008
Creator:
Price, Racheal
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
15th Street News (Midwest City, Okla.), Vol. 38, No. 24, Ed. 1 Friday, April 10, 2009
Newspaper from Rose State College in Midwest City, Oklahoma that includes national, local, and campus news along with advertising.
Date:
April 10, 2009
Creator:
Price, Racheal
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
A 1D Analysis of Direct and Indirect Drive Target Performance for Planar Hydrodynamics Experiments on the NIF
The 1D performance of laser or X-ray driven targets to study phenomena such as the Richtmyer-Meshkov instability in a single, steady shock, step down in density system has been described by a simple model based on 1D hydrodynamics. It is shown that the distance the interface travels under constant velocity conditions is a multiple of the separation between the ablation and shock front, and that this multiple depends on the density ratio at the interface, and the equations of states of the two materials. The model is applied to NIF with the aid of 1D hydrocode simulations to predict the ablation-shock separation. It is found that if adequate interface planarity can be maintained over an experimental length equal to the focal spot diameter, direct drive may out-perform indirect drive by up to {approx} factor 2 at the same pulse length and typically {ge} 2 at the same ablation pressure. This depends on the ability to control 2D effects in the directly driven targets (critically), and on the optimum hohlraum performance achievable for these experiments, rather than the achievable performance used for the study. It is predicted that several mm of constant velocity interface travel are potentially achievable on NIF, and …
Date:
July 10, 2000
Creator:
Edwards, M. J.
Object Type:
Report
System:
The UNT Digital Library