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Texas Historically Underutilized Business Annual Report:2001
Annual report documenting statistics and analysis of contracts awarded to historically underutilized business (HUBs) by Texas state agencies, including procurement goals and performances, 2000 and 2001 total expenditure charts.
Date:
October 15, 2001
Creator:
Texas. General Services Commission.
System:
The Portal to Texas History
ESTIMATES FOR RELEASE OF RADIONUCLIDES FROM POTENTIALLY CONTAMINATED CONCRETE AT THE HADDAM NECK NUCLEAR PLANT.
Decommissioning of the Haddam Neck Nuclear Power Plant operated by Connecticut Yankee is in progress. Figure 1 shows a schematic of the Containment Building and Spent Fuel Pool (SFP) Building. Consideration is being given to leaving some subsurface concrete from the Containment, Spent Fuel and certain other buildings in place following NRC license termination. Characterization data of most of these structures show small amounts of residual contamination. The In-Core Sump area of the Containment Building has shown elevated levels of tritium, Co-60, Fe-55, and Eu-152 and lesser quantities of other radionuclides due to neutron activation of the concrete in this area. This analysis is provided to determine levels of residual contamination that will not cause releases to the groundwater in excess of the acceptable dose limits. The objective is to calculate a conservative relationship between the radionuclide concentration of subsurface concrete and the maximum groundwater concentration (pCi/L) for the concrete that may remain following license termination at Connecticut Yankee.
Date:
September 15, 2004
Creator:
SULLIVAN, T.
System:
The UNT Digital Library
PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP: THEORY STUDIES FOR POLARIZED PP SCATTERING (VOLUME 53)
In the past two runs of RHIC, the first measurements with polarized proton beams have been performed. For many years to come, the RHIC spin program will offer exciting physics, exploring QCD and the nucleon in new ways. The aim of this small workshop was to attract several spin theorists to the center for about two weeks, in order to collaborate with both experimentalists and theorists at RBRC, and to initiate and/or complete studies of relevance to RHIC spin. A major focus of polarized-pp measurements at RHIC is on measuring the spin-dependent gluon density, {Delta}g. A channel for accessing {Delta}g is high-p{sub T} pion production. The unpolarized cross section for this reaction has been measured by PHENIX and was found in good agreement with a perturbative-QCD based (NLO) calculation. It was a remarkable and exciting coincidence that PHENIX presented also the first results for the spin asymmetry for {rvec p}{rvec p} {yields} {pi}{sup 0}X during this workshop. This sparked a lot of additional activity and discussion. First steps toward the interpretation of the data were taken. Marco Stratmann and Barbara Jager (Regensburg University) presented recent work on the NLO calculation of the polarized cross section and the spin asymmetry, setting …
Date:
September 15, 2003
Creator:
KRETZER,S. VOGELSANG,W.
System:
The UNT Digital Library
Environmentally Benign Stab Detonators
This effort attempts to demonstrate that environmentally acceptable energetic sol-gel coated flash metal multilayer nanocomposites can be used to replace current impact initiated devices (IIDs) which have hazardous and toxic components. Successful completion of this project will result in IIDs that include innocuous compounds, have sufficient output energy for initiation, meet current military specifications, are small, cost competitive, and perform as well as or better than current devices. We expect flash metal multilayer and sol-gel to be generic technologies applicable to a wide range of devices, especially in small caliber ammunition and sub-munitions. We will replace the NOL-130 mixture with a nanocomposite that consists of a mechanically robust energetic multilayer foil that has been coated with a sol-gel energetic material. The exothermic reactions are activated in this nanocomposite are the transformation of the multilayer material to its respective intermetallic alloy and the thermite reaction, which is characterized by very high temperatures, a small pressure pulse, and hot particle ejection. The proposed materials and their reaction products consist of, but are not limited to aluminum, nickel, iron, aluminum oxide, titanium, iron oxide and boron. These materials have much more desirable environmental and health characteristics than the NOL-130 composition.
Date:
December 15, 2003
Creator:
Gash, A.; Barbee, T.; Simpson, R.; Satcher, J. & Walton, C.
System:
The UNT Digital Library
Retrieval and Pipeline Transfer Assessment of Hanford Tank 241-AN-105 Waste
This study assesses five steps for Tank 241-AN-105 waste retrieval and subsequent pipeline transfer: 1. Remove supernatant liquid waste from AN-105 and transfer it through a pipeline with inline dilution with water (1st liquid waste transfer). 2. Add water (as a diluent) to Tank AN-105. 3. Mix the saltcake waste and water with mixer pumps to dissolve soluble solids. 4. Let undissolved solids settle to the tank bottom. 5. Remove the resulting supernatant liquid waste from Tank AN-105 (2nd liquid waste transfer). To assess these five steps for waste retrieval and pipeline transfer, AN-105 waste rheology was measured and solids identified with bright field image, select area diffraction, and energy dispersive x-ray spectroscopy. By combining available in situ and laboratory data, an AN-105 specific viscosity model was developed that can change from several centiPoise of viscosity to tens of millions of centiPoise as a function of strain rate and solid concentration. This viscosity mo del was implemented into the AN-105 computer model to simulate pump jet mixing. The report also evaluates AN-105 slurry waste transfer to AP-102 and AP-104 through a 3-inch (0.07-m) pipeline.
Date:
January 15, 2003
Creator:
Onishi, Yasuo; Tingey, Joel M.; Recknagle, Kurtis P.; Liu, Jun; Terrones, Guillermo; Yokuda, Satoru T. et al.
System:
The UNT Digital Library
Statistical Methods and Tools for Uxo Characterization (SERDP Final Technical Report)
The Strategic Environmental Research and Development Program (SERDP) issued a statement of need for FY01 titled Statistical Sampling for Unexploded Ordnance (UXO) Site Characterization that solicited proposals to develop statistically valid sampling protocols for cost-effective, practical, and reliable investigation of sites contaminated with UXO; protocols that could be validated through subsequent field demonstrations. The SERDP goal was the development of a sampling strategy for which a fraction of the site is initially surveyed by geophysical detectors to confidently identify clean areas and subsections (target areas, TAs) that had elevated densities of anomalous geophysical detector readings that could indicate the presence of UXO. More detailed surveys could then be conducted to search the identified TAs for UXO. SERDP funded three projects: those proposed by the Pacific Northwest National Laboratory (PNNL) (SERDP Project No. UXO 1199), Sandia National Laboratory (SNL), and Oak Ridge National Laboratory (ORNL). The projects were closely coordinated to minimize duplication of effort and facilitate use of shared algorithms where feasible. This final report for PNNL Project 1199 describes the methods developed by PNNL to address SERDP's statement-of-need for the development of statistically-based geophysical survey methods for sites where 100% surveys are unattainable or cost prohibitive.
Date:
November 15, 2004
Creator:
Pulsipher, Brent A.; Gilbert, Richard O.; Wilson, John E.; Hassig, Nancy L.; Carlson, Deborah K.; O'Brien, Robert F. et al.
System:
The UNT Digital Library
Quarterly Report (Reporting Period January 15, 2003 through April 15, 2003)
Summaries of the activities and accomplishments during this second quarter reporting period for each of the consortium participants are given. Some of the highlights for this reporting period include: Even without the forcing speaker, the ''Mozart'' device on the GCM geometry provides over 20% reduction in drag at 0 degree yaw and above 25% reductions at higher yaw angles; Experiments and computations guide a conceptual design for reduction of drag due to tractor-trailer gap flow; RANS simulations for the GTS geometry are being finalized for development of clear modeling guidelines with RANS; Simulations on the GCM geometry have begun; and Vortex methods have improved techniques for the treatment of vorticity near surfaces.
Date:
May 15, 2003
Creator:
McCallen, R.; Salari, K.; Ortega, J.; Browand, F.; Hammache, M.; Hsu, T. Y. et al.
System:
The UNT Digital Library
C-200 Series Tanks Vacuum Retrieval System Aerosol Test Results
The radioactive wastes stored in tanks 241-C-201, 241-C-202, 241-C-203, and 241-C-204 (the C-200 series tanks) are to be retrieved with the C-200 vacuum retrieval system (VRS). The VRS will suck the waste up through an articulated mast system, separate it from the suspending air, collect and transfer it to a receiver batch tank, and return the air as exhaust to the waste tank being retrieved. An analysis of potential accidents has indicated that a break in the line used to return the exhaust to the waste tank could release unacceptable quantities of suspended radioactive material to the environment. To estimate the quantity of suspended material and determine accident risks, CH2M HILL and Pacific Northwest National Laboratory (PNNL) conducted tests with the VRS using nonradioactive waste simulants at the Hanford Cold Test Facility. This report describes the tests conducted and presents and discusses the results.
Date:
September 15, 2003
Creator:
Huckaby, James L.; Glissmeyer, John A. & Gray, Paul E.
System:
The UNT Digital Library
Developing Smart Seismic Arrays: A Simulation Environment, Observational Database, and Advanced Signal Processing
Seismic imaging and tracking methods have intelligence and monitoring applications. Current systems, however, do not adequately calibrate or model the unknown geological heterogeneity. Current systems are also not designed for rapid data acquisition and analysis in the field. This project seeks to build the core technological capabilities coupled with innovative deployment, processing, and analysis methodologies to allow seismic methods to be effectively utilized in the applications of seismic imaging and vehicle tracking where rapid (minutes to hours) and real-time analysis is required. The goal of this project is to build capabilities in acquisition system design, utilization and in full 3D finite difference modeling as well as statistical characterization of geological heterogeneity. Such capabilities coupled with a rapid field analysis methodology based on matched field processing are applied to problems associated with surveillance, battlefield management, finding hard and deeply buried targets, and portal monitoring. This project benefits the U.S. military and intelligence community in support of LLNL's national-security mission. FY03 was the final year of this project. In the 2.5 years this project has been active, numerous and varied developments and milestones have been accomplished. A wireless communication module for seismic data was developed to facilitate rapid seismic data acquisition and …
Date:
September 15, 2003
Creator:
Harben, P E; Harris, D; Myers, S; Larsen, S; Wagoner, J; Trebes, J et al.
System:
The UNT Digital Library
Why Model-Based Engineering and Manufacturing Makes Sense for the Plants and Laboratories of the Nuclear Weapon Complex
The purpose of this White Paper is to outline the benefits we expect to receive from Model-Based Engineering and Manufacturing (MBE/M) for the design, analysis, fabrication, and assembly of nuclear weapons for upcoming Life Extension Programs (LEPs). Industry experiences with model-based approaches and the NNSA/DP investments and experiences, discussed in this paper, indicate that model-based methods can achieve reliable refurbished weapons for the stockpile with less cost and time. In this the paper, we list both general and specific benefits of MBE/M for the upcoming LEPs and the metrics for determining the success of model-based approaches. We also present some outstanding issues and challenges to deploying and achieving long-term benefit from the MBE/M. In conclusion, we argue that successful completion of the upcoming LEPs--with very aggressive schedule and funding restrictions--will depend on electronic model-based methods. We ask for a strong commitment from LEP managers throughout the Nuclear Weapons Complex to support deployment and use of MBE/M systems to meet their program needs.
Date:
May 15, 2001
Creator:
Franklin, K. W.; Howell, L. N., Jr.; Lewis, D. G.; Neugebauer, C. A.; O'Brien, D. W. & Schilling, S. A.
System:
The UNT Digital Library
Lawrence Livermore National Laboratory East Avenue/Emergency Response Planning Traffic Study
The Lawrence Livermore National Laboratory (LLNL) and the Sandia National Laboratory (SNL) are located at the eastern end of the City of Livermore. Recently the research facilities have been placed on heightened security alerts due to the events of September 11. To respond to the security concerns, LLNL and SNL have proposed to place East Avenue between South Vasco Road and Greenville Road under administrative control. This type of control would require security check points at both ends of this segment of East Avenue, including a truck inspection facility west of the Greenville Road intersection. In this configuration, East Avenue would be closed to general public traffic. The purpose of this traffic study is to determine the potential traffic impact of placing East Avenue under administrative control. The primary focus of the traffic study is to evaluate the proposed modifications to the geometry and operation of East Avenue between South Vasco Road and Greenville Road. The study also includes a review of a traffic study prepared for the closure of East Avenue in 1989 to determine if the assumptions and conclusions of that study remain valid.
Date:
February 15, 2002
Creator:
Schmiegel, T
System:
The UNT Digital Library
Progress Report on the Laboratory Testing of the Bulk Vitrification Cast Refractory
The Hanford Site in southeastern Washington State has been used extensively to produce nuclear materials for the U. S. strategic defense arsenal by the U. S. Department of Energy (DOE). A large inventory of radioactive and mixed waste has accumulated in 177 single- and double-shell tanks. Liquid waste recovered from the tanks will be pre-treated to separate the low-activity fraction from the high-level and transuranic wastes. Currently, the DOE Office of River Protection (ORP) is evaluating several options for immobilization of low-activity tank wastes for eventual disposal in a shallow subsurface facility at the Hanford Site. A significant portion of the waste will be converted into immobilized low-activity waste (ILAW) glass with a conventional Joule-heated ceramic melter. In addition to ILAW glass, supplemental treatment technologies are under consideration by the DOE to treat a portion of the low activity waste. The reason for using this alternative treatment technology is to accelerate the overall cleanup mission at the Hanford site. The ORP selected Bulk Vitrification (BV) for further development and testing. Work in FY03 on engineered and large scale tests of the BV process suggested that approximately 0.3 to as much as 3 wt% of the waste stream 99Tc inventory would …
Date:
November 15, 2004
Creator:
Pierce, Eric M.; McGrail, B PETER.; Bagaasen, Larry M.; Wellman, Dawn M.; Crum, J V.; Geiszler, Keith N. et al.
System:
The UNT Digital Library
Influence of Nitrate on the Hanford 100D Area In Situ Redox Manipulation Barrier Longevity
The purpose of this laboratory study is to determine the influence of nitrate on the Hanford 100D Area in situ redox manipulation (ISRM) barrier longevity. There is a wide spread groundwater plume of 60 mg/L nitrate upgradient of the ISRM barrier with lower nitrate concentrations downgradient, suggestive of nitrate reduction occurring. Batch and 1-D column experiments showed that nitrate is being slowly reduced to nitrite and ammonia. These nitrate reduction reactions are predominantly abiotic, as experiments with and without bactericides present showed no difference in nitrate degradation rates. Nitrogen species transformation rates determined in experiments covered a range of ferrous iron/nitrate ratios such that the data can be used to predict rates in field scale conditions. Field scale reaction rate estimates for 100% reduced sediment (16 C) are: (a) nitrate degradation = 202 {+-} 50 h (half-life), (b) nitrite production = 850 {+-} 300 h, and (c) ammonia production = 650 {+-} 300 h. Calculation of the influence of nitrate reduction on the 100D Area reductive capacity requires consideration of mass balance and reaction rate effects. While dissolved oxygen and chromate reduction rates are rapid and essentially at equilibrium in the aquifer, nitrate transformation reactions are slow (100s of hours). …
Date:
July 15, 2005
Creator:
Szecsody, Jim E.; Phillips, Jerry L.; Vermeul, Vince R.; Fruchter, Jonathan S. & Williams, Mark D.
System:
The UNT Digital Library
Rotational Bands and Isomeric States in 175lu
Rotational bands in {sup 175}Lu have been extended through investigation with the (n,n{prime}{gamma}) reaction. Spallation neutrons bombarded Lu samples, and the resulting {gamma} rays were detected in a large-scale Compton-suppressed Ge detector array. Prompt- and delayed-{gamma}{gamma} coincidences have been used to extend most of the existing known bands, and to tentatively assign a new band, based on the 7/2{sup -}[523] configuration, from its band head to spin 13/2. The 3-quasiparticle K{sup {pi}} = 19/2{sup +} isomer is confirmed and its half life determined to be 984 {+-} 13(stat.) {+-} 30(sys.) {micro}s, in agreement with previous results.
Date:
October 15, 2003
Creator:
Garrett, P. E.; Archer, D. E.; Becker, J. A.; Bernstein, L. A.; Hauschild, K.; Henry, E. A. et al.
System:
The UNT Digital Library
Calculating Contained Firing Facility (CFF) Explosive Firing Zones
Revision 1 of this document presented a method of calculating the CFF explosive firing zones that was based upon the peak average pressure on the various elements of the firing chamber as explosive weights and locations are changed. That document was reviewed internally at LLNL and reviewed by the design contractor of the facility. The contractor's responses generally confirmed the validity of the peak average pressure method, but noted that the shearing stresses at haunches may exceed the design values when explosive charges are moved towards comers. The concept of a dynamic load factor is introduced in the dynamic analysis section of Reference 5. A method is shown there whereby the response of the major elements of construction can be calculated from the knowledge of the peak average blast pressure averaged over the surface considered. the length of the pulse, and the natural period of vibration of the element. Quazi Hossain also suggested this method of analysis in Reference 2. The major elements of the Firing Chamber are the four walls, floor, roof slab, camera room overlay structure, inclined plate, bullnose, and the two doors. Except for the bullnose, their response has been calculated for a number of explosive weights …
Date:
February 15, 2001
Creator:
Lyle, J. W.
System:
The UNT Digital Library
Benson Beach Demonstration Project: Composition and Abundance of Biota at Three Alternative Sump Sites
The Portland District of the U.S. Army Corps of Engineers is investigating plans to provide sediment to nourish beaches north of the Mouth of the Columbia River (MCR). Under the currently designed proposal, sediment dredged from the MCR will be temporarily stored at one of three proposed areas south of the North Jetty before being redredged and moved by a cutterhead pipeline dredge over the jetty to nourish Benson Beach. Resulting potential impacts to resident Dungeness crab (Cancer magister) and fishes represent one of the criteria for evaluating each of the alternative locations. To establish the species composition and relative abundance of crabs and fishes associated with each of the three proposed sump areas, researchers from the Pacific Northwest National Laboratory Marine Sciences Division completed nine field sampling trips from July 8, 2003, to November 1, 2003, for a total of 113 successful trawls comprising an area of over 7.4 ha (74,156 m2). This report documents the results of that effort. To understand the relative risk of losses to crab populations associated with dredging impacts at the sump alternative areas, it is recommended that a modified dredge impact model be developed using the data collected in this study. This model …
Date:
January 15, 2004
Creator:
Williams, Greg D.; Pearson, Walter H.; Evans, Nathan R. & Anderson, Michael G.
System:
The UNT Digital Library
Density Measurements of Be Shells
The purpose of this memo is to lay out the uncertainties associated with the measurement of density of Be ablators by the weigh and volume method. I am counting on the readers to point out any faulty assumptions about the techniques or uncertainties associated with them. Based on the analysis presented below we should expect that 30 {micro}m thick shells will have an uncertainty in the measured density of about 2% of the value, coming more or less equally from the mass and volume measurement. The uncertainty is roughly inversely proportional to the coating thickness, thus a 60 {micro}m walled shell would result in a 1% uncertainty in the density.
Date:
February 15, 2005
Creator:
Cook, R C
System:
The UNT Digital Library
Optimal Resource Allocation in Electrical Network Defense
Infrastructure networks supplying electricity, natural gas, water, and other commodities are at risk of disruption due to well-engineered and coordinated terrorist attacks. Countermeasures such as hardening targets, acquisition of spare critical components, and surveillance can be undertaken to detect and deter these attacks. Allocation of available countermeasures resources to sites or activities in a manner that maximizes their effectiveness is a challenging problem. This allocation must take into account the adversary's response after the countermeasure assets are in place and consequence mitigation measures the infrastructure operation can undertake after the attack. The adversary may simply switch strategies to avoid countermeasures when executing the attack. Stockpiling spares of critical energy infrastructure components has been identified as a key element of a grid infrastructure defense strategy in a recent National Academy of Sciences report [1]. Consider a scenario where an attacker attempts to interrupt the service of an electrical network by disabling some of its facilities while a defender wants to prevent or minimize the effectiveness of any attack. The interaction between the attacker and the defender can be described in three stages: (1) The defender deploys countermeasures, (2) The attacker disrupts the network, and (3) The defender responds to the attack …
Date:
January 15, 2004
Creator:
Yao, Y; Edmunds, T; Papageorgiou, D & Alvarez, R
System:
The UNT Digital Library
The Influence of Selected Liquid and Soil Properties on the Propagation of Spills over Flat Permeable Surfaces
In an effort to determine spill characteristics, information about a spill's spatial distribution with time is being studied. For permeable surfaces, spill phenomenology is controlled by liquid and soil properties, the most relevant of which are presented in this report. The pertinent liquid and soil properties were tabulated for ten liquids and four soils. The liquids represented an array of organic compounds, some of which are or are soon to be documented in the liquid spectra library by the Environmental Molecular Science Laboratory at Pacific Northwest National Laboratory. The soils were chosen based on ongoing surface spectra work and to represent a range of relevant soil properties. The effect of the liquid and soil properties on spill phenomenology were explored using a spill model that couples overland flow described by gravity currents with the Green-Ampt infiltration model. From the simulations, liquid viscosity was found to be a controlling liquid property in determining the amount of time a spill remains on the surface, with the surface vanish time decreasing as viscosity decreased. This was attributed to decreasing viscosity increasing both the hydraulic conductivity of the soil and allowing for the spill to more quickly spread out onto an unsaturated soil surface. …
Date:
February 15, 2005
Creator:
Keller, Jason M. & Simmons, Carver S.
System:
The UNT Digital Library
Long-term, One-dimensional Simulation of Lower Snake River Temperatures for Current and Unimpounded Conditions
The objective of the study was to compare water temperatures in the Lower Snake River for current (impounded) and unimpounded conditions using a mathematical model of the river system. A long-term analysis was performed using the MASS1 one-dimensional (1D) hydrodynamic and water quality model. The analysis used historical flows and meteorological conditions for a 35-year period spanning between 1960 and 1995. Frequency analysis was performed on the model results to calculate river temperatures at various percent of time exceeded levels. Results were are also analyzed to compute the time when, during the year, water temperatures rose above or fell below various temperature levels. The long-term analysis showed that the primary difference between the current and unimpounded river scenarios is that the reservoirs decrease the water temperature variability. The reservoirs also create a thermal inertia effect which tends to keep water cooler later into the spring and warmer later into the fall compared to the unimpounded river condition. Given the uncertainties in the simulation model, inflow temperatures, and meteorological conditions the results show only relatively small differences between current and unimpounded absolute river temperatures.
Date:
February 15, 2001
Creator:
Perkins, William A. & Richmond, Marshall C.
System:
The UNT Digital Library
INTERNATIONAL CONFERENCE ON ULTRASHORT HIGH-ENERGY RADIATION AND MATTER
The workshop is intended as a forum to discuss the latest experimental, theoretical and computational results related to the interaction of high energy radiation with matter. High energy is intended to mean soft x-ray and beyond, but important new results from visible systems will be incorporated. The workshop will be interdisciplinary amongst scientists from many fields, including: plasma physics; x-ray physics and optics; solid state physics and material science; biology ; quantum optics. Topics will include, among other subjects: understanding damage thresholds for x-ray interactions with matter developing {approx} 5 keV x-ray sources to investigate damage; developing {approx} 100 keV Thomsom sources for material studies; developing short pulse (100 fs and less) x-ray diagnostics; developing novel X-ray optics; and developing models for the response of biological samples to ultra intense, sub ps x-rays high-energy radiation.
Date:
January 15, 2004
Creator:
Wootton, A J
System:
The UNT Digital Library
Simulating perforation permeability damage and cleanup
Completion of cased and cemented wells by shaped charge perforation causes its own damage to the formation, potentially reducing well productivity. In practice it is found that underbalance conditions clean up the damaged zone to some extent, however, the mechanisms of these processes are poorly understood. Most hydrocodes typically used to simulate rock response to shaped charge penetration do not provide permeability estimates. Furthermore, the time scales for formation clean up are potentially much longer than the period of jet penetration. We have developed a simple, yet accurate model for the evolution of porosity and permeability which can easily be incorporated into existing hydrocodes using information from the history of each cell. In addition, we have developed a code that efficiently simulates fines migration during the post-shot surge period using initial conditions taken directly from hydrocode simulations of jet penetration. Results from a one-dimensional model simulation are in excellent agreement with measured permeability distributions. We also present two-dimensional numerical results which qualitatively reproduce experimentally obtained permeability maps for different values of underbalance. Although initial results have been promising, further comparison with experiment is essential to tune the coupling between the hydrocode and fines migration simulator. Currently the permeability model is …
Date:
December 15, 2000
Creator:
Morris, J P; Lomov, I N & Glenn, L A
System:
The UNT Digital Library
Analytic Expressions for the Angular Resolution of Compton Gamma-ray Detectors
This paper describes the derivation of analytic expressions for the angular resolution of reconstructing gamma rays detected via Compton interactions. We consider two types of gamma-ray detectors: Compton-ring and electron-tracking devices. In Compton-ring devices, the direction of the scattered electron is not resolved, only the total energy (electron and scattered photon) and the scattered photon direction are measured. The measured quantities define a cone about the axis of the scattered photon direction. The initial photon direction lies along this cone. Thus for single events there is a ring-like ambiguity in the photon direction. By combining multiple events, the intersection of the reconstructed rings will resolve the initial direction of the photon source. In this paper, we derive the resolution of the cone angle for individual rings. Electron-tracking type devices resolve the electron path. Although the scattered electron subsequently undergoes multiple-Coulomb scattering, it is possible to measure the initial electron direction with sufficiently high tracking resolution. By measuring the direction and energy of the electron and the direction of the scattered photon, the initial photon direction can be uniquely determined. The challenge for this type of detector is achieving the high tracking resolution. In Section 2 we derive the well-known Compton …
Date:
January 15, 2004
Creator:
Wright, D M
System:
The UNT Digital Library
Ultrasonic Examination of Double-Shell Tank 241-AP-104. February 2005
COGEMA Engineering Corporation (COGEMA), under a contract from CH2M Hill Hanford Group (CH2M Hill), has performed an ultrasonic nondestructive examination of selected portions of Double-Shell Tank 241-AP-104. The purpose of this examination was to provide information that could be used to evaluate the integrity of the wall of the primary and secondary tank. The requirements for the ultrasonic examination of Tank 241-AP-104 were to detect, characterize (identify, size, and locate), and record measurements made of any wall thinning that might be present in the wall of the primary tank in the upper knuckle region, and any wall thinning, pitting, or cracks in the wall of the secondary tank in the lower knuckle region. Any measurements that exceed the requirements set forth in the Engineering Task Plan (ETP), RPP-22571 (Jensen 2004) and summarized on page 1 of this document, are reported to CH2M Hill and the Pacific Northwest National Laboratory (PNNL) for further evaluation. Under the contract with CH2M Hill, all data is to be recorded on disk and paper copies of all measurements are provided to PNNL for third-party evaluation. PNNL is responsible for preparing a report that describes the results of the COGEMA ultrasonic examinations.
Date:
March 15, 2005
Creator:
Pardini, Allan F. & Posakony, Gerald J.
System:
The UNT Digital Library