A PULSED EDDY CURRENT TEST SYSTEM USING REFLECTED FIELDS (open access)

A PULSED EDDY CURRENT TEST SYSTEM USING REFLECTED FIELDS

An eddy current test system is described in which the test information is detected as a series of fields reflected from the metal surface and interior. Pulsed electromagnetic fields are caused to impinge upon the test specimen. These fields are restricted to a small cross sectional area over a path in space long enough to be useful for test purposes by devices called mask-apenture assemblies. This approach provides a number of advantages over conventional eddy current methods of comparable capabilities, including superior surface resolution, a reduction in circuit complexity, and an improvement in stability and reliability. Various applications and test results are discussed. (auth)
Date: June 11, 1962
Creator: Renken, C. J.
Object Type: Article
System: The UNT Digital Library
Near Term Hybrid Passenger Vehicle Development Program. Phase I, Final report. Appendix B: trade-off studies. Volume I (open access)

Near Term Hybrid Passenger Vehicle Development Program. Phase I, Final report. Appendix B: trade-off studies. Volume I

Trade-off studies of Near Term Hybrid Vehicle (NTHV) design elements were performed to identify the most promising design concept in terms of achievable petroleum savings. The activities in these studies are described. The results are presented as preliminary NTHV body design, expected fuel consumption as a function of vehicle speed, engine requirements, battery requirements, and vehicle reliability and cost. (LCL)
Date: June 11, 1979
Creator: Traversi, M. & Piccolo, R.
Object Type: Report
System: The UNT Digital Library
Effects of oxide layers on optical properties and x-ray hardness of Al-Be mirrors (open access)

Effects of oxide layers on optical properties and x-ray hardness of Al-Be mirrors

Oxide layers form on the surfaces of many metallic mirrors. The oxidation may occur during fabrication or after the mirror is finished and installed. Some oxide layers may be intentionally added to protect the mirror or to change its optical properties. Computer calculations predict the effect of oxide layers on optical and ultraviolet reflectance as well as the x-ray absorption and concomitant thermal damage to the mirrors. 6 refs., 6 figs., 1 tab.
Date: June 11, 1991
Creator: White, R.H. & Wirtenson, G.R.
Object Type: Report
System: The UNT Digital Library
Framework for Analyzing Safeguards Alarms and Response Decisions (open access)

Framework for Analyzing Safeguards Alarms and Response Decisions

This paper describes a quantitative approach to help evaluate and respond to safeguards alarms. These alrms may be generated internally by a facility's safeguards systems or externally by individuals claiming to possess stolen Special Nuclear Material (SNM). This approach can be used to identify the most likely cause of an alarm - theft, hoax, or error - and to evaluate alternative responses to alarms. Possible responses include conducting investigations, initiating measures to recover stolen SNM, and replying to external threats. Based on the results of each alarm investigation step, the evaluation revises the likelihoods of possible causes of an alarm, and uses this information to determine the optimal sequence of further responses. The choice of an optimal sequence of responses takes into consideration the costs and benefits of successful thefts or hoaxes. These results provide an analytical basis for setting priorities and developing contingency plans for responding to safeguards alarms.
Date: June 11, 1982
Creator: Al-Ayat, R. A.; Judd, B. R. & McCord, R. K.
Object Type: Article
System: The UNT Digital Library
Fusion Breeder Program interim report (open access)

Fusion Breeder Program interim report

This interim report for the FY82 Fusion Breeder Program covers work performed during the scoping phase of the study, December, 1981-February 1982. The goals for the FY82 study are the identification and development of a reference blanket concept using the fission suppression concept and the definition of a development plan to further the fusion breeder application. The context of the study is the tandem mirror reactor, but emphasis is placed upon blanket engineering. A tokamak driver and blanket concept will be selected and studied in more detail during FY83.
Date: June 11, 1982
Creator: Moir, R.; Lee, J. D. & Neef, W.
Object Type: Report
System: The UNT Digital Library
Systematic efficiency enhancement in Monte Carlo applications. Final progress report, July 1, 1976-January 31, 1980 (open access)

Systematic efficiency enhancement in Monte Carlo applications. Final progress report, July 1, 1976-January 31, 1980

Research performed under the grant period has been undertaken as part of the principal investigator's long-term efforts to develop new, more efficient estimators for application to a wide variety of practical problems. Two rather different approaches have characterized the work: (1) the use of a multistage analysis (1) to optimize the efficiencies (variances) of families of estimating random variables in a traditional statistical Monte Carlo framework, and (2) the development of parallel quasi-random sampling techniques and corresponding deterministic error bounds.
Date: June 11, 1980
Creator: Spanier, J.
Object Type: Report
System: The UNT Digital Library
Parametric economic studies for inertial confinement fusion electric power plants (open access)

Parametric economic studies for inertial confinement fusion electric power plants

We have conducted parametric economic studies for inertial confinement fusion (ICF) electric power plants using an economic model to estimate the cost of electricity. We found that the economy of scale of the reactor is an important factor in determining the combination of target gain, driver efficiency, and electric conversion efficiency required for an economically competitive system. A strong economy of scale allows a significant reduction in these performance parameters for a given cost of electricity. The degree of reduction is dependent, however, on the maximum achievable chamber pulse rate.
Date: June 11, 1986
Creator: Meier, W. R. & Hogan, W. J.
Object Type: Article
System: The UNT Digital Library
An exponential model for HPGe detector efficiencies (open access)

An exponential model for HPGe detector efficiencies

Interest in reducing the labor-intensive requirements for calibrating HPGe detectors has resulted in various efficiency models. The present study examines a method for predicting the efficiencies over ranges of sample geometries, whereby only a few measurements are required. The method has been appraised against extensive HPGe calibrations, and has been used for a nondestructive'' calibration for samples from a NASA satellite.
Date: June 11, 1991
Creator: Winn, Willard G.
Object Type: Article
System: The UNT Digital Library
Benchmarking and Equipment and Controls Assessment for a 'Big Box' Retail Chain (open access)

Benchmarking and Equipment and Controls Assessment for a 'Big Box' Retail Chain

The paper describes work to enable improved energy performance of existing and new retail stores belonging to a national chain and thereby also identify measures and tools that would improve the performance of 'big box' stores generally. A detailed energy simulation model of a standard store design was developed and used to: (1) demonstrate the benefits of benchmarking the energy performance of retail stores of relatively standard design using baselines derived from simulation, (2) identify cost-effective improvements in the efficiency of components to be incorporated in the next design cycle, and (3) use simulation to identify potential control strategy improvements that could be adopted in all stores, improving operational efficiency. The core enabling task of the project was to develop an energy model of the current standard design using the EnergyPlus simulation program. For the purpose of verification of the model against actual utility bills, the model was reconfigured to represent twelve existing stores (seven relatively new stores and five older stores) in different US climates and simulations were performed using weather data obtained from the National Weather Service. The results of this exercise, which showed generally good agreement between predicted and measured total energy use, suggest that dynamic benchmarking …
Date: June 11, 2008
Creator: Haves, Philip; Coffey, Brian & Williams, Scott
Object Type: Article
System: The UNT Digital Library
Estimation of Radiation Doses in the Marshall Islands Based on Whole Body Counting of Cesium-137 (137Cs) and Plutonium Urinalysis (open access)

Estimation of Radiation Doses in the Marshall Islands Based on Whole Body Counting of Cesium-137 (137Cs) and Plutonium Urinalysis

Under the auspices of the U.S. Department of Energy (USDOE), researchers from the Lawrence Livermore National Laboratory (LLNL) have recently implemented a series of initiatives to address long-term radiological surveillance needs at former nuclear test sites in the Republic of the Marshall Islands (RMI). The aim of this radiological surveillance monitoring program (RSMP) is to provide timely radiation protection for individuals in the Marshall Islands with respect to two of the most important internally deposited fallout radionuclides-cesium-137 ({sup 137}Cs) and long-lived isotopes 239 and 240 of plutonium ({sup 239+240}Pu) (Robison et al., 1997 and references therein). Therefore, whole-body counting for {sup 137}Cs and a sensitive bioassay for the presence of {sup 239+240}Pu excreted in urine were adopted as the two most applicable in vivo analytical methods to assess radiation doses for individuals in the RMI from internally deposited fallout radionuclides (see Hamilton et al., 2006a-c; Bell et al., 2002). Through 2005, the USDOE has established three permanent whole-body counting facilities in the Marshall Islands: the Enewetak Radiological Laboratory on Enewetak Atoll, the Utrok Whole-Body Counting Facility on Majuro Atoll, and the Rongelap Whole-Body Counting Facility on Rongelap Atoll. These whole-body counting facilities are operated and maintained by trained Marshallese technicians. …
Date: June 11, 2007
Creator: Daniels, J.I.; Hickman, D.P.; Kehl, S.R. & Hamilton, T.F.
Object Type: Report
System: The UNT Digital Library
Remaining Sites Verification Package for the 100-C-9:1 Main Process Sewer Collection Line, Waste Site Reclassification Form 2004-012 (open access)

Remaining Sites Verification Package for the 100-C-9:1 Main Process Sewer Collection Line, Waste Site Reclassification Form 2004-012

The 100-C-9:1 main process sewer pipeline, also known as the twin box culvert, was a dual reinforced process sewer that collected process effluent from the 183-C and 190-C water treatment facilities, discharging at the 132-C-2 Outfall. For remedial action purposes, the 100-C-9:1 waste site was subdivided into northern and southern sections. The 100-C-9:1 subsite has been remediated to achieve the remedial action objectives specified in the Remaining Sites ROD. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.
Date: June 11, 2007
Creator: Dittmer, L. M.
Object Type: Report
System: The UNT Digital Library
Neutrino Physics with the IceCube Detector (open access)

Neutrino Physics with the IceCube Detector

IceCube is a cubic kilometer neutrino telescope under construction at the South Pole.The primary goal is to discover astrophysical sources of high energy neutrinos.We describe the detector and present results on atmospheric muon neutrinos from2006 data collected with nine detector strings.
Date: June 11, 2008
Creator: Collaboration, IceCube; Kiryluk, Joanna & Kiryluk, Joanna
Object Type: Article
System: The UNT Digital Library
Advanced Computing Tools and Models for Accelerator Physics (open access)

Advanced Computing Tools and Models for Accelerator Physics

This paper is based on a transcript of my EPAC'08 presentation on advanced computing tools for accelerator physics. Following an introduction I present several examples, provide a history of the development of beam dynamics capabilities, and conclude with thoughts on the future of large scale computing in accelerator physics.
Date: June 11, 2008
Creator: Ryne, Robert & Ryne, Robert D.
Object Type: Article
System: The UNT Digital Library
Supersymmetry with Small mu: Connections between Naturalness, DarkMatter, and (Possibly) Flavor (open access)

Supersymmetry with Small mu: Connections between Naturalness, DarkMatter, and (Possibly) Flavor

Weak scale supersymmetric theories often suffer from several naturalness problems: the problems of reproducing the correct scale for electroweak symmetry breaking, the correct abundance for dark matter, and small rates for flavor violating processes. We argue that the first two problems point to particular regions of parameter space in models with weak scale supersymmetry: those with a small {mu} term. This has an interesting implication on direct dark matter detection experiments. We find that, if the signs of the three gaugino mass parameters are all equal, we can obtain a solid lower bound on the spin-independent neutralino-nucleon cross section, {sigma}{sub SI}. In the case that the gaugino masses satisfy the unified mass relations, we obtain {sigma}{sub SI} {approx}> 4 x 10{sup -46} cm{sup 2} (1 x 10{sup -46} cm{sup 2}) for fine-tuning in electroweak symmetry breaking no worse than 10% (5%). We also discuss a possibility that the three problems listed above are all connected to the hierarchy of fermion masses. This occurs if supersymmetry breaking and electroweak symmetry breaking (the Higgs fields) are coupled to matter fields with similar hierarchical structures. The discovery of {mu} {yields} e transition processes in near future experiments is predicted in such a framework.
Date: June 11, 2006
Creator: Kitano, Ryuichiro Kitano & Nomura, Yasunori
Object Type: Article
System: The UNT Digital Library
Three-dimensional analysis of free-electron laser performance using brightness scaled variables (open access)

Three-dimensional analysis of free-electron laser performance using brightness scaled variables

A three-dimensional analysis of radiation generation in a free-electron laser (FEL) is performed in the small signal regime. The analysis includes beam conditioning, harmonic generation, flat beams, and a new scaling of the FEL equations using the six-dimensional beam brightness. The six-dimensional beam brightness is an invariant under Liouvillian flow; therefore, any nondissipative manipulation of the phase-space, performed, for example, in order to optimize FEL performance, must conserve this brightness. This scaling is more natural than the commonly-used scaling with the one-dimensional growth rate. The brightness-scaled equations allow for the succinct characterization of the optimal FEL performance under various additional constraints. The analysis allows for the simple evaluation of gain enhancement schemes based on beam phase space manipulations such as emittance exchange and conditioning. An example comparing the gain in the first and third harmonics of round or flat and conditioned or unconditioned beams is presented.
Date: June 11, 2008
Creator: Penn, Gregory; Gullans, M.; Penn, G.; Wurtele, J.S. & Zolotorev, M.
Object Type: Article
System: The UNT Digital Library
Vacuum Chamber Design of NSLS-II Storage Ring (open access)

Vacuum Chamber Design of NSLS-II Storage Ring

National Synchrotron Light Source II (NSLS II) will be a 3-GeV, 792-meter circumference, 3rd generation synchrotron radiation facility, with ultra low emittance and extremely high brightness. the storage ring has 30 Double-Bend-Achromatic (DBA) cells. in each cell, there are five magnets and chamber girders, and one straight section for insertion devices or Radio Frequency (RF) cavities or injection. Most vacuum chambers are made from extruded aluminum with two different cross sections: one fitted in the dipole magnets, and the other surrounded by multipole magnets. They discuss the layout of the DBA cells, the detailed design of the cell's vacuum chambers, the mounting of the Beam-Position-Monitor (BPM) buttons, discrete absorbers, lumped pumps and the distributed Non-Evaporable Getter (NEG) strips, and describe the fabrication and testing of these prototype cell chambers. The account also details the development of the chamber bakeout process, the NEG stri's supports, and the RF shielded bellows.
Date: June 11, 2008
Creator: Doom,L.; Ferreira, M.; Hseuh, H. C.; Lincoln, F.; Longo, C.; Ravindranath, V. et al.
Object Type: Article
System: The UNT Digital Library
242-16H 2H EVAPORATOR POT SAMPLING FINAL REPORT (open access)

242-16H 2H EVAPORATOR POT SAMPLING FINAL REPORT

Due to the materials that are processed through 2H Evaporator, scale is constantly being deposited on the surfaces of the evaporator pot. In order to meet the requirements of the Nuclear Criticality Safety Analysis/Evaluation (NCSA/NCSE) for 2H Evaporator, inspections of the pot are performed to determine the extent of scaling. Once the volume of scale reaches a certain threshold, the pot must be chemically cleaned to remove the scale. Prior to cleaning the pot, samples of the scale are obtained to determine the concentration of uranium and plutonium and also to provide information to assist with pot cleaning. Savannah River National Laboratory (SRNL) was requested by Liquid Waste Organization (LWO) Engineering to obtain these samples from two locations within the evaporator. Past experience has proven the difficulty of successfully obtaining solids samples from the 2H Evaporator pot. To mitigate this risk, a total of four samplers were designed and fabricated to ensure that two samples could be obtained. Samples had previously been obtained from the cone surface directly below the vertical access riser using a custom scraping tool. This tool was fabricated and deployed successfully. A second scraper was designed to obtain sample from the nearby vertical thermowell and a …
Date: June 11, 2008
Creator: Krementz, D & William Cheng, W
Object Type: Report
System: The UNT Digital Library
A New Chicane Experiment in PEP-II to Test Mitigations of the Electron Cloud Effect for Linear Colliders (open access)

A New Chicane Experiment in PEP-II to Test Mitigations of the Electron Cloud Effect for Linear Colliders

Beam instability caused by the electron cloud has been observed in positron and proton storage rings, and it is expected to be a limiting factor in the performance of future colliders [1-3]. The effect is expected to be particularly severe in magnetic field regions. To test possible mitigation methods in magnetic fields, we have installed a new 4-dipole chicane experiment in the PEP-II Low Energy Ring (LER) at SLAC with both bare and TiN-coated aluminum chambers. In particular, we have observed a large variation of the electron flux at the chamber wall as a function of the chicane dipole field. We infer this is a new high order resonance effect where the energy gained by the electrons in the positron beam depends on the phase of the electron cyclotron motion with respect to the bunch crossing, leading to a modulation of the secondary electron production. Presumably the cloud density is modulated as well and this resonance effect could be used to reduce its magnitude in future colliders. We present the experimental results obtained during January 2008 until the April final shut-down of the PEP-II machine.
Date: June 11, 2008
Creator: Pivi, M. T.; Pivi, M. T. F.; Ng, J. S. T.; Arnett, D.; Cooper, F.; Kharakh, D. et al.
Object Type: Article
System: The UNT Digital Library
Sipping fuel and saving lives: increasing fuel economy withoutsacrificing safety (open access)

Sipping fuel and saving lives: increasing fuel economy withoutsacrificing safety

The public, automakers, and policymakers have long worried about trade-offs between increased fuel economy in motor vehicles and reduced safety. The conclusion of a broad group of experts on safety and fuel economy in the auto sector is that no trade-off is required. There are a wide variety of technologies and approaches available to advance vehicle fuel economy that have no effect on vehicle safety. Conversely, there are many technologies and approaches available to advance vehicle safety that are not detrimental to vehicle fuel economy. Congress is considering new policies to increase the fuel economy of new automobiles in order to reduce oil dependence and reduce greenhouse gas emissions. The findings reported here offer reassurance on an important dimension of that work: It is possible to significantly increase the fuel economy of motor vehicles without compromising their safety. Automobiles on the road today demonstrate that higher fuel economy and greater safety can co-exist. Some of the safest vehicles have higher fuel economy, while some of the least safe vehicles driven today--heavy, large trucks and SUVs--have the lowest fuel economy. At an October 3, 2006 workshop, leading researchers from national laboratories, academia, auto manufacturers, insurance research industry, consumer and environmental groups, …
Date: June 11, 2007
Creator: Gordon, Deborah; Greene, David L.; Ross, Marc H. & Wenzel, Tom P.
Object Type: Report
System: The UNT Digital Library
Nucleon Structure and Hyperon Form Factors from Lattice QCD. (open access)

Nucleon Structure and Hyperon Form Factors from Lattice QCD.

In this work, I report the latest lattice QCD calculations of nucleon and hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All calculations are done with a chirally symmetric fermion action, domain-wall fermions, for valence quarks. I begin with the latest lattice results on the nucleon structure, focusing on results from RBC/UKQCD using 2+1-flavor chiral fermion actions. We find the chiral-extrapolated axial coupling constant at physical pion mass point. to be 1.23(5), consistent with experimental value. The renormalization constants for the structure functions are obtained from RI/MOM-scheme non-perturbative renormalization. We find first moments of the polarized and unpolarized nucleon structure functions at zero transfer momentum to be 0.133(13) and 0.203(23) respectively, using continuum chiral extrapolation. These are consistent with the experimental values, unlike previous calculations which have been 50% larger. We also have a prediction for the transversity, which we find to be 0.56(4). The twist-3 matrix element is consistent with zero which agrees with the prediction of the Wandzura-Wilczek relation. In the second half of this work, I report an indirect dynamical estimation of the strangeness proton magnetic moments using mixed actions. With the analysis of hyperon form factors and using charge symmetry, the strangeness of proton is …
Date: June 11, 2007
Creator: Lin, H. W.
Object Type: Article
System: The UNT Digital Library
Spatial Disaggregation of CO2 Emissions for the State of California (open access)

Spatial Disaggregation of CO2 Emissions for the State of California

This report allocates California's 2004 statewide carbon dioxide (CO2) emissions from fuel combustion to the 58 counties in the state. The total emissions are allocated to counties using several different methods, based on the availability of data for each sector. Data on natural gas use in all sectors are available by county. Fuel consumption by power and combined heat and power generation plants is available for individual plants. Bottom-up models were used to distribute statewide fuel sales-based CO2 emissions by county for on-road vehicles, aircraft, and watercraft. All other sources of CO2 emissions were allocated to counties based on surrogates for activity. CO2 emissions by sector were estimated for each county, as well as for the South Coast Air Basin. It is important to note that emissions from some sources, notably electricity generation, were allocated to counties based on where the emissions were generated, rather than where the electricity was actually consumed. In addition, several sources of CO2 emissions, such as electricity generated in and imported from other states and international marine bunker fuels, were not included in the analysis. California Air Resource Board (CARB) does not include CO2 emissions from interstate and international air travel, in the official California …
Date: June 11, 2008
Creator: de la Rue du Can, Stephane; de la Rue du Can, Stephane; Wenzel, Tom & Fischer, Marc
Object Type: Report
System: The UNT Digital Library
The Flux and Recovery of Bioactive Substances in the Surface Sediments of Deep Basins Off Southern California (open access)

The Flux and Recovery of Bioactive Substances in the Surface Sediments of Deep Basins Off Southern California

Sediment microbial community biomass and activity in Santa Monica Basin, a nearshore basin in the California Continental Borderland, were examined in October 1985, 1986 and 1987, May 1986, April 1987 and January 1990. Millimeter-scale ATP profiles and incubation of intact cores with {sup 3}H-adenine indicated a high-biomass interface microbial population in the low-oxygen central basin, which was absent in samples from the basin slope sediments. A majority of microbial activity and organic matter mineralization occurred in the top cm of sediment. Comparison of measured ATP and total organic carbon profiles suggest that the C:ATP ratio (wt:wt) ranges between 47:1 and 77:1 in central basin interfacial populations, substantially lower than reported for other aquatic environments. Carbon production estimated from DNA synthesis measurements via {sup 3}H-adenine incorporation was compared with TCO{sub 2} fluxes measured by in situ benthic chamber experiments. Within the uncertainty of the C:ATP ratio, an overall microbial carbon assimilation efficiency of 75--90% was indicated. The low C:ATP ratios and high carbon assimilation efficiencies significantly affect estimates of microbial growth and respiration and are substantially different than those often assumed in the literature. These results suggest that without independent knowledge of these ratios, the uncertainty in tracer-derived microbial growth and …
Date: June 11, 1990
Creator: Jahnke, R. A.
Object Type: Report
System: The UNT Digital Library
Project vulcan heater: centerbody casting. [25. 5 Cr--5. 5 Ni--2. 00 Mo--3. 00 Cu steel] (open access)

Project vulcan heater: centerbody casting. [25. 5 Cr--5. 5 Ni--2. 00 Mo--3. 00 Cu steel]

Specifications for casting the centerbody housing of the vulcan heater are provided. CD-4MCu steel has been specified for the centerbody and the properties of the steel are given. (FS)
Date: June 11, 1979
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Sintering kinetics of pure and doped boron carbide (open access)

Sintering kinetics of pure and doped boron carbide

The sintering of pure and doped boron carbide was investigated over the temperature range 1898 to 2380/sup 0/K and at additive levels ranging from 0.75 to 10.0%. The addition of 0.75 and 3.8 wt% of AlF/sub 3/, Ni, Fe, and Cu deactivated the sintering of B/sub 4/C at all temperatures. In contrast, the addition of 10.0 wt% these additives resulted in enhanced shrinkage in B/sub 4/C for the temperatures 1898 and 2133/sup 0/K. At the highest temperature, 2380/sup 0/K, the addition of 10.0 wt% AlF/sub 3/ was the only case where enhanced shrinkage was observed. In this case, x-ray analysis showed the formation of a B/sub 12/C/sub 2/Al compound and the release of fluorine. These results are interpreted in terms of a grain-boundary diffusion process for pure and doped B/sub 4/C.
Date: June 11, 1979
Creator: Lange, R. G.; Munir, Z. A. & Holt, J. B.
Object Type: Article
System: The UNT Digital Library