Determination of Heavy Water Purity by Infrared Absorption (open access)

Determination of Heavy Water Purity by Infrared Absorption

The practical application of heavy water purity determination by infrared absorption spectroscopy using standard laboratory equipment was demonstrated in connection with the operation of heavy water-moderated Special Power Excursion Reactor Test (SPERT II) Facillty at the NRTS. (auth)
Date: January 16, 1962
Creator: Abernathey, R. M. & Morgan, T. D.
Object Type: Report
System: The UNT Digital Library
Oxidation/gasification of carbon residue on retorted oil shale. Final report (open access)

Oxidation/gasification of carbon residue on retorted oil shale. Final report

Studies of the oxidation and gasification of oil shale char were extended to an investigation of the effects of mineral catalysis. Six shales with differing mineral compositions were studied, including samples from the saline zone in the Western Colorado and from the Antrim shales of Michigan. Oxidation kinetics data, corrected for mass transfer effects, were compared for all six samples. A high assay shale from Utah and a sample from the saline zone were found to have the highest oxidation rates. By examining the data for shales which were water leached and thermally pretreated, it was concluded that both NaO and CaO act as oxidation catalysts. However, as a result of mineral decomposition experiments conducted with a sample from the C-a lease tract, it appears as though the ankeritic dolomite fraction will not decompose as long as there is a minimal CO/sub 2/ over pressure. Rather, low temperature silication reactions appear to take place once the temperature exceeds 925/sup 0/K. An extensive evaluation was also completed for the gasification of an Antrim shale from Michigan. Both the rates of CO/sub 2/ and steam gasification of the char were found to be markedly lower than that observed for a shale sample …
Date: January 16, 1984
Creator: Thomson, W. J.
Object Type: Report
System: The UNT Digital Library
Introduction to albedo neutron dosimeters (open access)

Introduction to albedo neutron dosimeters

The design, operation, calibration, and performance of albedo neutron dosimeters are discussed. An albedo neutron dosimeter is designed to measure the flux of thermal neutrons which leave the body when a person is exposed to fast energy neutrons. The fast neutrons are scattered and moderated in the body, and many have lost most of their initial energy and emerge as thermal neutrons. The albedo neutron dosimeter is designed to detect this flux of thermal neutrons by using a thermal neutron detector. This could be any type of thermal neutron detector but in practical applications lithium fluoride (LiF) thermoluminescence dosimeters (TLDs) are most frequently used. Various types of albedo neutron dosimeters are described. (WHK)
Date: January 16, 1978
Creator: Hankins, D.E.
Object Type: Article
System: The UNT Digital Library
Secondary recovery of plutonium and americium from process waste streams by solvent extraction (open access)

Secondary recovery of plutonium and americium from process waste streams by solvent extraction

A solvent extraction process is being evaluated for the secondary recovery of plutonium and americium from Rocky Flats waste streams. The bidentate organophosphorus compounds dihexyl-N,N-diethylcarbamylmethylene phosphonate and its dibutyl analogue have been shown to be selective extractants for the actinides from solutions of nitric acid. The results from laboratory test runs in which the organophosphorus extractants were used for processing secondary waste solutions will be presented. Solvent extractant properties and purification procedures are discussed.
Date: January 16, 1978
Creator: Hagan, P. G. & Navratil, J. D.
Object Type: Article
System: The UNT Digital Library
Laser-assisted solar cell metallization processing. Quarterly report, September 13-December 12, 1983 (open access)

Laser-assisted solar cell metallization processing. Quarterly report, September 13-December 12, 1983

The Westinghouse Electric Corporation has undertaken to investigate, develop, and characterize laser-assisted processing techniques utilized to produce the fine line, thin metal grid structures that are required to fabricate high-efficiency solar cells. Two basic techniques for metal deposition will be investigated, as follows: (1) photochemical decomposition of liquid or gas phase organometallic compounds utilizing either a focused, CW ultraviolet laser (System 1) or a mask and ultraviolet flood illumination, such as that provided by a repetitively pulsed, defocused excimer laser (System 2), for pattern definition, and (2) thermal deposition of metals from organometallic solutions or vapors utilizing a focused, CW laser beam as a local heat source to draw the metallization pattern. The purpose of this contract is to investigate the various existing laser-assisted film deposition techniques in order to develop a new, cost-effective technology for solar cell metallization. The tasks that will be performed in the conduct of these investigations are detailed. In the first three months of this contract, a comprehensive literature search has been carried out on the various state-of-the-art laser-assisted techniques for metal deposition, including laser chemical vapor deposition and laser photolysis of organometallics, as well as laser-enhanced electroplating. A compact system for the experiments involving …
Date: January 16, 1984
Creator: Dutta, S.
Object Type: Report
System: The UNT Digital Library
Etiology of contaminated wounds (open access)

Etiology of contaminated wounds

The US Department of Energy reports of events that occurred in the chemical processing 200 Areas of the Hanford Site during the period from 1972 through 1986 were reviewed to identify the causes of contaminated wounds. Contaminated wounds were reported in 19 events involving 20 workers. The causal agents (high risk operations) and the root causes were characterized. Emergency actions taken and their efficacy were noted. The 19 wound events were compared with 17 events with the potential for inhalation. It was found that the wound events involve a single worker and frequently result in an internal contamination and its resulting dose. Inhalation events involve groups of workers and rarely resulted in detectable internal contamination. The difference is attributed to anticipation of an inhalation event and use of respiratory protection and continuous air monitors to mitigate its effects.
Date: January 16, 1992
Creator: Sudmann, R.H.
Object Type: Article
System: The UNT Digital Library
Radioiostope studies utilizing a low level whole body counter and clinical application of activation analysis. Progress report (open access)

Radioiostope studies utilizing a low level whole body counter and clinical application of activation analysis. Progress report

The main emphasis of these studies is the development of methods (hardware and software) for the quantitation of body and specific organ burdens of radioactivity. Current work is directed toward the evaluation of radiation dose distributions in human beings from new radioactive tracers and new procedures used in nuclear medicine. Dosimetry and clinical studies will be carried out on patients using new radiopharmaceuticals where dosimetry data are lacking. Future efforts will be directed toward the development of systems that will facilitate the collection of dosimetry data using less specialized facilities. The availability of instrumentation and analytic techniques that provide clinical images as well as dosimetry data should enhance the rate of collection of data on human exposures in medicine and assist in the optimization of diagnostic strategies. In parallel with these efforts, we are developing a new computer assisted technique for diagnostic decision making. The basic aim is to utilize efficiently all the available data to maximize information gain while minimizing cost factors.
Date: January 16, 1980
Creator: Brill, A. B. & Price, R. R.
Object Type: Report
System: The UNT Digital Library
Integrated system for production of neutronics and photonics calculational constants. Volume 5, Part B. Relativistic transformations between center-of-mass and laboratory systems for two-body nuclear reactions (open access)

Integrated system for production of neutronics and photonics calculational constants. Volume 5, Part B. Relativistic transformations between center-of-mass and laboratory systems for two-body nuclear reactions

A technique is described for transforming cross sections and secondary-particle energies between center-of-mass and laboratory systems for two-body nuclear reactions. The derivations of the relativistic transformations needed for this technique are also reviewed.
Date: January 16, 1978
Creator: Howerton, Robert J.
Object Type: Report
System: The UNT Digital Library
Separation and Characterization of Coal Derived Components. Quarterly Report, 1 October 1983-31 December 1983 (open access)

Separation and Characterization of Coal Derived Components. Quarterly Report, 1 October 1983-31 December 1983

No new field-ionization data was obtained this quarter. For preasphaltenes, elemental analysis data was obtained on Kentucky and Wyodak preasphaltene samples. In conjunction with the preasphaltene work, solubility and thin-layer chromatography experiments were performed. The results indicated that basic alumina would not be useful as a general stationary phase for the separation of preasphaltenes. Several experiments were carried out with Chromasorb T, and the results showed it would be an adequate substitute for Fluoropak. The hydrocarbons in a sample from Pittsburgh Energy Technology Center were separated by the number of double bonds. The optimum mobile phases for the separation of monohydroxyl aromatics and dihydroxyl aromatics by reversed-phase liquid chromatography were obtained. In addition, a means of predicting retention in normal-phase chromatography was considered, and a NO/sub 2/ high-performance chromatographic column showed promise for the separation of compound classes. 6 references, 4 figures, 7 tables.
Date: January 16, 1984
Creator: Hurtubise, R. H. & Silver, H. F.
Object Type: Report
System: The UNT Digital Library
Failure of latch mechanism for motion control of safety rods (open access)

Failure of latch mechanism for motion control of safety rods

During safety rod tests in K-reactor prior to startup, one safety rod could not be lifted because the button'' broke off and became lodged in the mechanism. Examination of the failed latch assembly along with other assemblies from both K-Area and L-Area revealed several missing buttons as well as severely deformed jaw hanger extensions.'' We participated in the investigation of the damage by request of the Reactor Restart Section. Based on our study of the latch mechanism, the modifications to the safety rod extension,'' and the operating history of the machine, this memorandum describes the causes of the observed damage with experimental evidence and calculations to support the findings. 3 refs.
Date: January 16, 1992
Creator: Yau, W. W. F. & Leader, D. R.
Object Type: Report
System: The UNT Digital Library
Inventory and relative biological hazard of LMFBR core materials (open access)

Inventory and relative biological hazard of LMFBR core materials

Information on the composition of an LMFBR core by element has been collected on the basis of published design data and ORIGEN calculations. The mass quantities of structural materials, actinides, and fission products are in the ratio of 1:1.4:0.1 with actinides, particularly plutonium and neptunium, representing the major inhalation and ingestion hazard. Some of the fission products are present in quantities large enough to suggest that they warrant specific attention in source term analysis.
Date: January 16, 1978
Creator: Tobias, M.L.
Object Type: Report
System: The UNT Digital Library
NERSC Cyber Security Challenges That Require DOE Development andSupport (open access)

NERSC Cyber Security Challenges That Require DOE Development andSupport

Traditional security approaches do not adequately addressall the requirements of open, scientific computing facilities. Many ofthe methods used for more restricted environments, including almost allcorporate/commercial systems, do not meet the needs of today's science.Use of only the available "state of the practice" commercial methods willhave adverse impact on the ability of DOE to accomplish its sciencegoals, and impacts the productivity of the DOE Science community. Inparticular, NERSC and other high performance computing (HPC) centers havespecial security challenges that are unlikely to be met unless DOE fundsdevelopment and support of reliable and effective tools designed to meetthe cyber security needs of High Performance Science. The securitychallenges facing NERSC can be collected into three basic problem sets:network performance and dynamics, application complexity and diversity,and a complex user community that can have transient affiliations withactual institutions. To address these problems, NERSC proposes thefollowing four general solutions: auditing user and system activityacross sites; firewall port configuration in real time;cross-site/virtual organization identity management and access control;and detecting security issues in application middleware. Solutions arealsoproposed for three general long term issues: data volume,application complexity, and information integration.
Date: January 16, 2007
Creator: Draney, Brent; Campbell, Scott & Walter, Howard
Object Type: Report
System: The UNT Digital Library
Relative Biological Effectiveness of HZE Fe Ions for Induction of Micro-Nuclei at Low Doses (open access)

Relative Biological Effectiveness of HZE Fe Ions for Induction of Micro-Nuclei at Low Doses

Dose-response curves for induction of micro-nuclei (MN) was measured in Chinese hamster V79 and xrs6 (Ku80-) cells and in human mammary epithelial MCF10A cells in the dose range of 0.05-1 Gy. The Chinese Hamster cells were exposed to 1 GeV/u Fe ions, 600 MeV/u Fe ions, and 300 MeV/u Fe ions (LETs of 151, 176 and 235 keV/{micro}m respectively) as well as with 320 kVp X-rays as reference. Second-order polynomials were fitted to the induction curves and the initial slopes (the alpha values) were used to calculate RBE. For the repair proficient V79 cells the RBE at these low doses increased with LET. The values obtained were 3.1 (LET=151 keV/{micro}m), 4.3 (LET = 176 keV/{micro}m) and 5.7 (LET = 235 keV/{micro}m), while the RBE was close to 1 for the repair deficient xrs6 cells regardless of LET. For the MCF10A cells the RBE was determined for 1 GeV/u Fe ions and found to be 5.4, slightly higher than for V79 cells. To test the effect of shielding, the 1 GeV/u Fe ion beam was intercepted by various thickness of high-density polyethylene plastic absorbers, which resulted in energy loss and fragmentation. It was found that the MN yield for V79 cells …
Date: January 16, 2007
Creator: Groesser, Torsten; Chun, Eugene & Rydberg, Bjorn
Object Type: Article
System: The UNT Digital Library
On the non-invariance of space and time scale ranges under Lorentztransformation, and its implications for the study of relativisticinteractions (open access)

On the non-invariance of space and time scale ranges under Lorentztransformation, and its implications for the study of relativisticinteractions

We present an analysis which shows that the ranges of space and time scales spanned by a system are not invariant under the Lorentz transformation. This implies the existence of a frame of reference which minimizes an aggregate measure of the range of space and time scales. Such a frame is derived for example cases: free electron laser, laser-plasma accelerator, and particle beam interacting with electron clouds. Implications for experimental, theoretical and numerical studies are discussed. The most immediate relevance is the reduction by orders of magnitude in computer simulation run times for such systems.
Date: January 16, 2007
Creator: Vay, J. L.
Object Type: Article
System: The UNT Digital Library
A Study of Factorization and a Measurement of CP Violation (open access)

A Study of Factorization and a Measurement of CP Violation

We report on a study of the decay {bar B}{sup 0} {yields} D*{sup +} {omega}{pi}{sup -} with the BABAR detector at the PEP-II B-factory at the Stanford Linear Accelerator Center. Based on a sample of 232 million B{sup 0}{bar B}{sup 0} decays collected between 1999 and 2004, we measure the branching fraction {Beta}({bar B}{sup 0} {yields} D*{sup +} {omega}{pi}{sup -}) = (2.88 {+-} 0.21(stat.) {+-} 0.31(syst.)) x 10{sup -3}. We study the invariant mass spectrum of the {omega}{pi}{sup -} system in this decay. This spectrum is in good agreement with expectations based on factorization and the measured spectrum in {tau}{sup -} {yields} {omega}{pi}{sup -} {nu}{sub {tau}}. We also measure the polarization of the D*{sup +} as a function of the {omega}{pi}{sup -} mass. In the mass region 1.1 to 1.9 GeV we measure the fraction of longitudinal polarization of the D*{sup +} to be {Lambda}{sub L}/{Lambda} = 0.654 {+-} 0.042(stat.) {+-} 0.016(syst.). This is in agreement with the expectations from heavy-quark effective theory and factorization assuming that the decay proceeds as {bar B}{sup 0} {yields} D*{sup +} {rho}(1450){sup -}, {rho}(1450){sup -} {yields} {omega}{pi}{sup -}. Furthermore, we present the results on the time-dependent CP asymmetry in neutral B meson decays to …
Date: January 16, 2008
Creator: Dahmes, Bryan
Object Type: Thesis or Dissertation
System: The UNT Digital Library
ARPES study of the evolution of band structure and charge density wave properties in RTe3 ( R=Y , La, Ce, Sm, Gd, Tb, and Dy) (open access)

ARPES study of the evolution of band structure and charge density wave properties in RTe3 ( R=Y , La, Ce, Sm, Gd, Tb, and Dy)

We present a detailed angle-resolved photoemission spectroscopy (ARPES) investigation of the RTe3 family, which sets this system as an ideal"textbook" example for the formation of a nesting driven charge density wave (CDW). This family indeed exhibits the full range of phenomena that can be associated to CDWinstabilities, from the opening of large gaps on the best nested parts of Fermi surface (up to 0.4 eV), to the existence of residual metallic pockets. ARPES is the best suited technique to characterize these features, thanks to its unique ability to resolve the electronic structure in k space. An additional advantage of RTe3 is that theband structure can be very accurately described by a simple two dimensional tight-binding (TB) model, which allows one to understand and easily reproduce many characteristics of the CDW. In this paper, we first establish the main features of the electronic structure by comparing our ARPES measurements with the linear muffin-tinorbital band calculations. We use this to define the validity and limits of the TB model. We then present a complete description of the CDW properties and of their strong evolution as a function of R. Using simple models, we are able to reproduce perfectly the evolution of gaps …
Date: January 16, 2008
Creator: Hussain, Zahid; Brouet, Veronique; Yang, Wanli; Zhou, Xingjiang; Hussain, Zahid; Moore, R. G. et al.
Object Type: Article
System: The UNT Digital Library
A Simultaneous Measurement of the Branching Fractions of Ten B to Double Charm Decays (open access)

A Simultaneous Measurement of the Branching Fractions of Ten B to Double Charm Decays

This dissertation presents a simultaneous measurement of the branching fractions of ten B {yields} D{sup (*)}{bar D}{sup (*)} decays. The measurements are derived from a sample of 2.32 x 10{sup 8} B{bar B} pairs collected by the BABAR detector at the PEP-II B Factory located at Stanford Linear Accelerator Center. The branching fractions (x 10{sup -4}) are: -0.10 {+-} 0.44 {+-} 0.15 (<0.59) for B{sup 0} {yields} D{sup 0}{bar D}{sup 0}; 1.01 {+-} 1.07 {+-} 0.35 (<2.92) for B{sup 0} {yields} D*{sup 0}{bar D}{sup 0}; -1.31 {+-} 1.05 {+-} 0.41 (<0.92) for B{sup 0} {yields} D*{sup 0}{bar D}*{sup 0}; 2.81 {+-} 0.43 {+-} 0.45 for B{sup 0} {yields} D{sup +}D{sup -}; 5.72 {+-} 0.64 {+-} 0.71 for B{sup 0} {yields} D*{sup +}D{sup -}; 8.11 {+-} 0.57 {+-} 0.97 for B{sup 0} {yields} D*{sup +}D*{sup -}; 3.76 {+-} 0.57 {+-} 0.45 for B{sup -} {yields} D{sup -}D{sup 0}; 3.56 {+-} 0.52 {+-} 0.39 for B{sup -} {yields} D*{sup -}D{sup 0}; 6.30 {+-} 1.32 {+-} 0.93 for B{sup -} {yields} D{sup -}D*{sup 0}; and 8.14 {+-} 1.17 {+-} 1.11 for B{sup -} {yields} D*{sup -}D*{sup 0}. The first uncertainty is statistical while the second is systematic. The number in parentheses is the …
Date: January 16, 2008
Creator: Lae, Chung Khim
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Heights integrated model as instrument for simulation of hydHeights Integrated Model as Instrument for Simulation of Hydrodynamic, Radiation Transport, and Heat Conduction Phenomena of Laser-Produced Plasma in EUV Applications. (open access)

Heights integrated model as instrument for simulation of hydHeights Integrated Model as Instrument for Simulation of Hydrodynamic, Radiation Transport, and Heat Conduction Phenomena of Laser-Produced Plasma in EUV Applications.

The HEIGHTS integrated model has been developed as an instrument for simulation and optimization of laser-produced plasma (LPP) sources relevant to extreme ultraviolet (EUV) lithography. The model combines three general parts: hydrodynamics, radiation transport, and heat conduction. The first part employs a total variation diminishing scheme in the Lax-Friedrich formulation (TVD-LF); the second part, a Monte Carlo model; and the third part, implicit schemes with sparse matrix technology. All model parts consider physical processes in three-dimensional geometry. The influence of a generated magnetic field on laser plasma behavior was estimated, and it was found that this effect could be neglected for laser intensities relevant to EUV (up to {approx}10{sup 12} W/cm{sup 2}). All applied schemes were tested on analytical problems separately. Benchmark modeling of the full EUV source problem with a planar tin target showed good correspondence with experimental and theoretical data. Preliminary results are presented for tin droplet- and planar-target LPP devices. The influence of three-dimensional effects on EUV properties of source is discussed.
Date: January 16, 2007
Creator: Sizyuk, V.; Hassanein, A.; Morozov, V.; Sizyuk, T. & Science, Mathematics and Computer
Object Type: Report
System: The UNT Digital Library
Propagation or failure of detonation across an air gap in an LX-17 column: continuous time-dependent detonation or shock speed using the Embedded Fiber Optic (EFO) technique (open access)

Propagation or failure of detonation across an air gap in an LX-17 column: continuous time-dependent detonation or shock speed using the Embedded Fiber Optic (EFO) technique

The detailed history of the shock/detonation wave propagation after crossing a room-temperature-room-pressure (RTP) air gap between a 25.4 mm diameter LX-17 donor column and a 25.4 mm diameter by 25.4 mm long LX-17 acceptor pellet is investigated for three different gap widths (3.07, 2.08, and 0.00 mm) using the Embedded Fiber Optic (EFO) technique. The 2.08 mm gap propagated and the 3.07 mm gap failed and this can be seen clearly and unambiguously in the EFO data even though the 25.4 mm-long acceptor pellet would be considered quite short for a determination by more traditional means such as pins.
Date: January 16, 2008
Creator: Hare, D E; Chandler, J B; Compton, S M; Garza, R G; Grimsley, D A; Hernandez, A et al.
Object Type: Report
System: The UNT Digital Library
Pitfalls of Transparency: Lessons Learned from the Milford Flats Fire (open access)

Pitfalls of Transparency: Lessons Learned from the Milford Flats Fire

The Community Environmental Monitoring Program (CEMP) consists of a network of 29 radiation and weather monitoring stations located over a 160,000-km2 area of southern Nevada, southwestern Utah, and southeastern California. The program provides stakeholders with a hands-on role in the monitoring for airborne radioactivity that could result from ongoing or past activities on the Nevada Test Site (NTS). The CEMP’s mission includes provisions for the transparency of the monitoring data as well as public accessibility to these data. This is accomplished through direct stakeholder participation, public outreach, and near real-time uploads of monitoring data to a publicly accessible web site located at http://cemp.dri.edu/. In early July 2007, a lightning strike ignited a wildfire just outside the city of Milford in southeastern Utah. This fire, named the Milford Flats Fire, grew rapidly and eventually became the largest wildfire in recorded history in the state, burning approximately 567 square miles. At about the same time, the pressurized ion chamber (PIC) located at the CEMP station in Milford began reporting average exposure rates that ranged from four to seven times normal for the area. Initially, it was believed that elevated readings could be a result of gamma-emitting radon progeny released by the fire …
Date: January 16, 2008
Creator: Hartwell, T.; Shafer, D.; Tappen, J.; McCurdy, G.; Hurley, B. & Farmer, D.
Object Type: Article
System: The UNT Digital Library
Inverse-Transition Radiation Laser Acceleration Experiments at SLAC (open access)

Inverse-Transition Radiation Laser Acceleration Experiments at SLAC

We present a series of laser-driven particle acceleration experiments that are aimed at studying laser-particle acceleration as an inverse-radiation process. To this end we employ a semi-open vacuum setup with a thin planar boundary that interacts with the laser and the electromagnetic field of the electron beam. Particle acceleration from different types of boundaries will be studied and compared to the theoretical expectations from the Inverse-radiation picture and the field path integral method. We plan to measure the particle acceleration effect from transparent, reflective, black, and rough surface boundaries. While the agreement between the two acceleration pictures is straightforward to prove analytically for the transparent and reflective boundaries the equivalence is not clear-cut for the absorbing and rough-surface boundaries. Experimental observation may provide the evidence to distinguish between the models.
Date: January 16, 2008
Creator: Colby, Eric R.; Ischebeck, R.; Mcguinness, C.; Noble, R. J.; Sears, CMS; Siemann, Robert H. et al.
Object Type: Article
System: The UNT Digital Library
METHODOLOGY AND CALCULATIONS FOR THE ASSIGNMENT OF WASTE GROUPS FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE (open access)

METHODOLOGY AND CALCULATIONS FOR THE ASSIGNMENT OF WASTE GROUPS FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE

The Hanford Site contains 177 large underground radioactive waste storage tanks (28 double-shell tanks and 149 single-shell tanks). These tanks are categorized into one of three waste groups (A, B, and C) based on their waste and tank characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement gas release event. Assignments of waste groups to the 177 double-shell tanks and single-shell tanks, as reported in this document, are based on a Monte Carlo analysis of three criteria. The first criterion is the headspace flammable gas concentration following release of retained gas. This criterion determines whether the tank contains sufficient retained gas such that the well-mixed headspace flammable gas concentration would reach 100% of the lower flammability limit if the entire tank's retained gas were released. If the volume of retained gas is not sufficient to reach 100% of the lower flammability limit, then flammable conditions cannot be reached and the tank is classified as a waste group C tank independent of the method the gas is released. The second criterion is the energy ratio and considers whether there …
Date: January 16, 2009
Creator: RA, WEBER
Object Type: Report
System: The UNT Digital Library
Binary Pseudo-random Grating Standard for Calibration of Surface Profilometers (open access)

Binary Pseudo-random Grating Standard for Calibration of Surface Profilometers

We suggest and describe the use of a binary pseudo-random (BPR) grating as a standard test surface for measurement of the modulation transfer function (MTF) of interferometric microscopes. Knowledge of the MTF of a microscope is absolutely necessary to convert the measured height distribution of a surface undergoing metrology into an accurate power spectral density (PSD) distribution. For an'ideal' microscope with an MTF function independent of spatial frequency out to the Nyquist frequency of the detector array with zero response at higher spatial frequencies, a BPR grating would produce a flat 1D PSD spectrum, independent of spatial frequency. For a'real' instrument, the MTF is found as the square root of the ratio of the PSD spectrum measured with the BPR grating to the'ideal,' spatial frequency independent, PSD spectrum. We present the results from a measurement of the MTF of MicromapTM-570 interferometric microscope demonstrating a high efficiency for the calibration method.
Date: January 16, 2008
Creator: Yashchuk, Valeriy; Yashchuk, Valeriy V.; McKinney, Wayne R. & Takacs, Peter Z.
Object Type: Article
System: The UNT Digital Library
Seismic Data for Evaluation of Ground Motion Hazards in Las Vegas in Support of Test Site Readiness Ground Motion (open access)

Seismic Data for Evaluation of Ground Motion Hazards in Las Vegas in Support of Test Site Readiness Ground Motion

In this report we describe the data sets used to evaluate ground motion hazards in Las Vegas from nuclear tests at the Nevada Test Site. This analysis is presented in Rodgers et al. (2005, 2006) and includes 13 nuclear explosions recorded at the John Blume and Associates network, the Little Skull Mountain earthquake and a temporary deployment of broadband station in Las Vegas. The data are available in SAC format on CD-ROM as an appendix to this report.
Date: January 16, 2008
Creator: Rodgers, A
Object Type: Report
System: The UNT Digital Library