States

Plan for Using Solar-Powered Jack Pumps to Sample Groundwater at the Nevada Test Site (open access)

Plan for Using Solar-Powered Jack Pumps to Sample Groundwater at the Nevada Test Site

Groundwater is sampled from 39 monitoring wells on the Nevada Test Site (NTS) as part of the Routine Radiological Environmental Monitoring Program. Many of these wells were not designed or constructed for long-term groundwater monitoring. Some have extensive completion zones and others have obstructions such as pumps and tubing. The high-volume submersible pumps in some wells are unsuitable for long-term monitoring and result in large volumes of water that may have to be contained and characterized before subsequent disposition. The configuration of most wells requires sampling stagnant well water with a wireline bailer. Although bailer sampling allows for the collection of depth-discrete samples, the collected samples may not be representative of local groundwater because no well purging is done. Low-maintenance, solar-powered jack pumps will be deployed in nine of these onsite monitoring wells to improve sample quality. These pumps provide the lift capacity to produce groundwater from the deep aquifers encountered in the arid environment of the NTS. The water depths in these wells range from 700 to 2,340 ft below ground surface. The considerable labor and electrical power requirements of electric submersible pumps are eliminated once these pumps are installed. Access tubing will be installed concurrent with the installation …
Date: May 3, 2007
Creator: David Hudson, Charles Lohrstorfer, Bruce Hurley
Object Type: Article
System: The UNT Digital Library
Assessing the Performance of 5mm White LED Light Sources forDeveloping-Country Applications (open access)

Assessing the Performance of 5mm White LED Light Sources forDeveloping-Country Applications

Some white light-emitting diode (LED) light sources haverecently attained levels of efficiency and cost that allow them tocompete with fluorescent lighting for off-grid applications in thedeveloping world. Additional attributes (optics, size, ruggedness, andservice life) make them potentially superior products. Enormousreductions in energy use and greenhouse-gas emissions are thus possible,and system costs can be much lower given the ability to downsize thecharging and energy storage components compared to a fluorescentstrategy. However, there is a high risk of "market-spoiling" if inferiorproducts are introduced and result in user dissatisfaction. Completesystems involve the integration of light sources and optics, energysupply, and energy storage. A natural starting point for evaluatingproduct quality is to focus on the individual light sources. This reportdescribes testing results for batches of 10 5mm white LEDs from 26manufacturers. Efficacies and color properties are presented.
Date: May 3, 2007
Creator: Mills, Evan
Object Type: Report
System: The UNT Digital Library
Tomographic wavefront correction for the LSST (open access)

Tomographic wavefront correction for the LSST

The Large Synoptic Survey Telescope (LSST) is a three mirror modified Paul-Baker design with an 8.4m primary, a 3.4m secondary, and a 5.0m tertiary followed by a 3-element refractive corrector producing a 3.5 degree field of view. This design produces image diameters of <0.3 arcsecond 80% encircled energy over its full field of view. The image quality of this design is sufficient to ensure that the final images produced by the telescope will be limited by the atmospheric seeing at an excellent astronomical site. In order to maintain this image quality, the deformations and rigid body motions of the three large mirrors must be actively controlled to minimize optical aberrations. By measuring the optical wavefront produced by the telescope at multiple points in the field, mirror deformations and rigid body motions that produce a good optical wavefront across the entire field may be determined. We will describe the details of the techniques for obtaining these solutions. We will show that, for the expected mirror deformations and rigid body misalignments, the solutions that are found using these techniques produce an image quality over the field that is close to optimal. We will discuss how many wavefront sensors are needed and the …
Date: May 3, 2006
Creator: Phillion, D. W.; Olivier, S. S.; Baker, K.; Seppala, L. & Hvisc, S.
Object Type: Article
System: The UNT Digital Library
Future Accelerator Challenges in Support of High-Energy Physics (open access)

Future Accelerator Challenges in Support of High-Energy Physics

Historically, progress in high-energy physics has largely been determined by development of more capable particle accelerators. This trend continues today with the imminent commissioning of the Large Hadron Collider at CERN, and the worldwide development effort toward the International Linear Collider. Looking ahead, there are two scientific areas ripe for further exploration--the energy frontier and the precision frontier. To explore the energy frontier, two approaches toward multi-TeV beams are being studied, an electron-positron linear collider based on a novel two-beam powering system (CLIC), and a Muon Collider. Work on the precision frontier involves accelerators with very high intensity, including a Super-BFactory and a muon-based Neutrino Factory. Without question, one of the most promising approaches is the development of muon-beam accelerators. Such machines have very high scientific potential, and would substantially advance the state-of-the-art in accelerator design. The challenges of the new generation of accelerators, and how these can be accommodated in the accelerator design, are described. To reap their scientific benefits, all of these frontier accelerators will require sophisticated instrumentation to characterize the beam and control it with unprecedented precision.
Date: May 3, 2008
Creator: Zisman, M. S.
Object Type: Article
System: The UNT Digital Library
ESTIMATING THE STRENGTH OF SINGLE-ENDED DISLOCATION SOURCES IN MICROMETER-SIZED SINGLE CRYSTALS (open access)

ESTIMATING THE STRENGTH OF SINGLE-ENDED DISLOCATION SOURCES IN MICROMETER-SIZED SINGLE CRYSTALS

A recent study indicated that the behavior of single-ended dislocation sources contributes to the flow strength of micrometer-scale crystals. In this study 3D discrete dislocation dynamics simulations of micrometer-sized volumes are used to calculate the effects of anisotropy of dislocation line tension (increasing Poisson's ratio, {nu}) on the strength of single-ended dislocation sources and, to compare them with the strength of double-ended sources of equal length. This is done by directly modeling their plastic response within a 1 micron cubed FCC Ni single crystal using DDS. In general, double-ended sources are stronger than single-ended sources of an equal length and exhibit no significant effects from truncating the long-range elastic fields at this scale. The double-ended source strength increases with Poisson ratio ({nu}), exhibiting an increase of about 50% at u = 0.38 (value for Ni) as compared to the value at {nu} = 0. Independent of dislocation line direction, for {nu} greater than 0.20, the strengths of single-ended sources depend upon the sense of the stress applied. The value for {alpha}, in the expression for strength, {tau} = {alpha}(L){micro}b/L is shown to vary from 0.4 to 0.84 depending upon the character of the dislocation and the direction of operation of …
Date: May 3, 2007
Creator: Rao, S I; Dimiduk, D M; Tang, M; Parthasarathy, T A; Uchic, M D & Woodward, C
Object Type: Article
System: The UNT Digital Library
Gated Microchannel Plate Photomultiplier For Longitudinal BeamDiagnostics (open access)

Gated Microchannel Plate Photomultiplier For Longitudinal BeamDiagnostics

A gated microchannel plate photomultiplier can be used as aneffective tool for measuring the longitudinal distribution of particlesaround most electron and high-energy proton rings. The broad availablewavelength range,low noise, and high sensitivity allow using such adevice for measuring the emitted synchrotron radiation and to extract thebeam intensity. The fast gate rise time can be used to reject strongsignals coming from filled RF buckets and avoid saturation of thephotocathode so that it is possible to monitor, with a high degree ofresolution, gaps in the machine fill and growth of parasitic bunches. Therugged characteristics of the device and its simplicity of use make itideal for all those applications where more complex and expensiveinstrumentation is not absolutely necessary. We present the experimentalresults obtained at the Advanced Light Source and on the Tevatron usingan Hamamatsu R5916U-50 series model.
Date: May 3, 2006
Creator: Byrd, John M.; De Santis, Stefano & Thurman-Keup, Randy
Object Type: Article
System: The UNT Digital Library
High-energy coherent THz radiation from laser wakefieldaccelerated ultrashort electron bunches (open access)

High-energy coherent THz radiation from laser wakefieldaccelerated ultrashort electron bunches

None
Date: May 3, 2004
Creator: van Tilborg, J.; Fubiani, G. J.; Geddes, C. G. R.; Toth, C.; Esarey, E.; Schroeder, C. B. et al.
Object Type: Article
System: The UNT Digital Library
Design of Spintronic Materials with Simple Structures (open access)

Design of Spintronic Materials with Simple Structures

A brief comparison of conventional electronics and spintronics is given. The key features of half metallic binary compounds with the zincblende structure are presented, using MnAs as an example. We discuss the interactions responsible for the half metallic properties. Special properties of superlattices and a digital ferromagnetic heterostructure incorporating zincblende half metals are also discussed.
Date: May 3, 2007
Creator: Fong, C Y; Qian, M C; Liu, K; Yang, L H & Pask, J E
Object Type: Article
System: The UNT Digital Library
Temporal changes in noble gas compositions within the Aidlinsector ofThe Geysers geothermal system (open access)

Temporal changes in noble gas compositions within the Aidlinsector ofThe Geysers geothermal system

The use of nonreactive isotopic tracers coupled to a full thermal-hydrological reservoir simulation allows for an improved method of investigating how reservoir fluids contained within matrix and fractures contribute over time to fluids produced from geothermal systems. A combined field and modeling study has been initiated to evaluate the effects of injection, production, and fracture-matrix interaction on produced noble gas contents and isotopic ratios. Gas samples collected periodically from the Aidlin steam field at The Geysers, California, between 1997 and 2006 have been analyzed for their noble gas compositions, and reveal systematic shifts in abundance and isotopic ratios over time. Because of the low concentrations of helium dissolved in the injection waters, the injectate itself has little impact on the helium isotopic composition of the reservoir fluids over time. However, the injection process may lead to fracturing of reservoir rocks and an increase in diffusion-controlled variations in noble gas compositions, related to gases derived from fluids within the rock matrix.
Date: May 3, 2006
Creator: Dobson, Patrick; Sonnenthal, Eric; Kennedy, Mack; van Soest,Thijs & Lewicki, Jennifer
Object Type: Article
System: The UNT Digital Library
Saturating interactions in /sup 4/He with density dependence (open access)

Saturating interactions in /sup 4/He with density dependence

With the advent of larger and faster computers, as well as modern shell model codes, nuclear structure calculations for the light nuclei (A<16) which include full 2/bar h/..omega.. model spaces are quite feasible. However, there can be serious problems in the mixing of 2/bar h/..omega.. and higher excitations into the low-lying spectra if the effective interaction is non-saturating. Furthermore, effective interactions which are both saturating and density dependent have not generally been used in previous nuclear structure calculations. Therefore, we have undertaken studies of /sup 4/He using two-body potential interactions which incorporate both saturation and density-dependence. Encouraging initial results in remedying the mixing of 0 and 2/bar h/..omega.. excitations have been obtained. We have also considered the effects of our interaction on the /sup 4/He compressibility and the centroid of the breathing mode strength. First indications are that a saturating effective interaction, with a short-range density dependent part and a long-range density independent part, comes close to matching crude predictions for the compressibility of /sup 4/He. 11 refs., 6 tabs.
Date: May 3, 1989
Creator: Bloom, S.D.; Resler, D.A. & Moszkowski, S.A.
Object Type: Article
System: The UNT Digital Library
Neutron Spectral Measurements in the D0 Collision Hall (open access)

Neutron Spectral Measurements in the D0 Collision Hall

The characterization of radiation fields is important to many applications. For example, in operational health physics, the choice of instrumentation for monitoring and of a personnel dosimeter for use by radiation workers depend on both the type and spectral characteristics of the radiation. Furthermore, the spectral distribution of the fluence affects radiation damage estimates for materials for new or replacement equipment within the radiation environment. At the same time, knowledge of the character of the radiation fields at a high-energy accelerator leads to a better theoretical understanding of its nature, and is important to the specification of civil construction requirements for future upgrades of the accelerator. At Fermilab as at many high-energy accelerators neutrons dominate the radiation fields outside of beam pipes within enclosures. In a continuing effort to characterize as completely as possible the fields at various locations around the site, we have measured the neutron spectrum within the DO collision hall. Both the fluence and dose-equivalent energy distributions are summarized in this note. 12 refs., 4 figs., 2 tabs.
Date: May 3, 1989
Creator: Yurista, P. M.; Elwyn, A. J. & Salsbury, W. C.
Object Type: Report
System: The UNT Digital Library
High Resolution Spectrometer in studies of e/sup +/e/sup -/ annihilation at. sqrt. s = 29 GeV (open access)

High Resolution Spectrometer in studies of e/sup +/e/sup -/ annihilation at. sqrt. s = 29 GeV

The High Resolution Spectrometer is a general-purpose spectrometer which measures both charged particles and electromagnetic energy over 90% of the solid angle. The detection elements are in a 1.62-T magnetic field. The detector elements consist of a central drift chamber, an outer drift-chamber system, a barrel shower counter, and an end-cap shower-counter system. The goals of the program of research with the High Resolution Spectrometer include measurements of the electroweak coupling of the quarks and leptons, studies of the strong interactions of the quarks, and search for qualitatively new phenomena. 20 refs., 35 figs. (LEW)
Date: May 3, 1985
Creator: Derrick, M.
Object Type: Article
System: The UNT Digital Library
Fuel system and structural alloy considerations for space nuclear reactor systems (open access)

Fuel system and structural alloy considerations for space nuclear reactor systems

Sufficient data exist to provide a high level of confidence that refractory-alloy-clad ceramic fuel pins and refractory structural alloys can be used successfully in an operational space power system. However, data are not yet sufficient to ensure that these materials can meet the temperature, lifetime, and system mass envelope requirements for reliable operation of a 100 kW(e) system as specified by the SP-100 Project. Development efforts to provide these data are being initiated.
Date: May 3, 1981
Creator: Hoffman, E.E. & Cooper, R.H. Jr.
Object Type: Article
System: The UNT Digital Library
DT fusion neutron irradiation of BNL--LASL superconductor wires, LASL YAG, Al/sub 2/O/sub 3/ and Spinel, LASL-IIT MgO, YAG, Al/sub 2/O/sub 3/ and Spinel, and NRL GeO/sub 2/ crystals, December 28, 1977 (open access)

DT fusion neutron irradiation of BNL--LASL superconductor wires, LASL YAG, Al/sub 2/O/sub 3/ and Spinel, LASL-IIT MgO, YAG, Al/sub 2/O/sub 3/ and Spinel, and NRL GeO/sub 2/ crystals, December 28, 1977

The DT fusion neutron irradiation of eleven BNL-LAST superconductor wires, six NRL GeO/sub 2/ crystals, two YAG, two Spinel and two Al/sub 2/O/sub 3/ crystals for LASL and four LASL high purity single crystals of MgO, YAG, Spinel and Al/sub 2/O/sub 3/ is described. The sample position, beam-on time, and neutron dose record are given. The maximum fluence on any sample was 1.51 x 10/sup 16/ neutrons/cm/sup 2/.
Date: May 3, 1978
Creator: MacLean, S.C.
Object Type: Report
System: The UNT Digital Library
A Fast Online Event Display for a High Intensity Fixed-Target Spectrometer (open access)

A Fast Online Event Display for a High Intensity Fixed-Target Spectrometer

A workstation-based event display program for the Fermilab Tagged Photon Spectrometer (TPS) is described. Fast displays are required to monitor detector elements, observe hit patterns and energy deposition, and to check track reconstruction. Design considerations, novel features, and performance are designed. 5 refs., 4 figs., 1 tab.
Date: May 3, 1990
Creator: Napier, Austin
Object Type: Article
System: The UNT Digital Library
Combustibility of tetraphenylborate solids (open access)

Combustibility of tetraphenylborate solids

Liquid slurries expected under normal in-tank processing (ITP) operations are not ignitible because of their high water content. However, deposits of dry solids from the slurries are combustible and produce dense, black smoke when burned. The dry solids burn similarly to Styrofoam and more easily than sawdust. It is the opinion of fire hazard experts that a benzene vapor deflagration could ignite the dry solids. A tetraphenylborate solids fire will rapidly plug the waste tank HEPA ventilation filters due to the nature of the smoke produced. To prevent ignition and combustion of these solids, the waste tanks have been equipped with a nitrogen inerting system.
Date: May 3, 1989
Creator: Walker, D. D.
Object Type: Report
System: The UNT Digital Library
Summary of climatic input for waste management site suitability criteria and state of progress (open access)

Summary of climatic input for waste management site suitability criteria and state of progress

Because groundwater movement can have important effects on buried nuclear wastes, hydrologists need to know if future climatic changes will influence the accuracy of groundwater flow calculations. Groundwater recharge (and therefore groundwater flow) depends on surface water balance. (Surface water balance equals precipitation less losses to evaporation, runoff, and storage.) To develop input data for modeling future climatic effects, we have made the following simplifying assumptions: (1) Climate (and therefore water balance) will behave in the future very much as it has in the past. (2) Groundwater recharge responds linearly to precipitation. (3) Future long-term climatic changes can be classified into groups or regimes that are similar to those of the past. Our current research is aimed at providing input data to the Waste Management Program's site suitability task. 16 figures, 1 table.
Date: May 3, 1978
Creator: Potter, G.L.
Object Type: Report
System: The UNT Digital Library
Experimental evaluation of vertically versus horizontally split yokes for SSC (Superconducting Super Collider) dipole magnets (open access)

Experimental evaluation of vertically versus horizontally split yokes for SSC (Superconducting Super Collider) dipole magnets

The yoke in SSC dipole magnets provides mechanical support to the collared coil as well as serving as a magnetic element. The yoke and skin are used to increase the coil prestress and reduce collar deflections under excitation. Yokes split on the vertical or horizontal mid-plane offer different advantages in meeting these objectives. To evaluate the relative merits of the two configuration a 1.8 m model dipole was assembled and tested first with horizontally split and then with vertically split yoke laminations. The magnet was extensively instrumented to measure azimuthal and axial stresses in the coil and the cold mass skin resulting from cooldown and excitation. Mechanical behavior of this magnet with each configuration is compared with that of other long and short models and with calculations. 13 refs., 5 figs.
Date: May 3, 1990
Creator: Strait, J.; Coulter, K.; Jaffery, T.; Kerby, J.; Koska, W. & Lamm, M.J.
Object Type: Article
System: The UNT Digital Library
Integrated computer-enhanced remote viewing system. Quarterly report No. 2, January--March 1993 (open access)

Integrated computer-enhanced remote viewing system. Quarterly report No. 2, January--March 1993

The Interactive, Computer-Enhanced, Remote Viewing System (ICERVS) is a system designed to provide a reliable geometric description of a robotic task space in a fashion that enables robotic remediation to be carried out more efficiently and economically than with present systems. The key elements are a faithful way to store empirical data and a friendly user interface that provides an operator with timely access to all that is known about a scene.
Date: May 3, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Fast Neutron Fluxes in Hanford Reactors (open access)

Fast Neutron Fluxes in Hanford Reactors

The results of a multi-group, diffusion type code computation for the fast neutron flux distribution in C, K, and N reactors are presented. Relative Ni activations in conjunction with the calculated neutron spectra are used to obtain values for the integrated fast flux per MWD/AT for C and K reactors. The relative, theoretical, integrated fast flux values at the same adjacent fuel powers in C, K, and N reactors in the mid-plane of the filler layers are: (1) C = 1.0; (2) K = 1.3; and (3) N = 2.6. For C reactor, the best estimate of the integrated fast flux per MWD/AT is: 5.0 {times} 10{sup 16} nvt (> 1 MeV) = 1 MWD/AT.
Date: May 3, 1960
Creator: Yoshikawa, H. H.
Object Type: Report
System: The UNT Digital Library
Development of More Efficacious {Tc}-99m Organ Imaging Agents for Use in Nuclear Medicine by Analytical Characterization of Radiopharmaceuticals. Annual Technical Progress Report, September 1, 1992--August 31, 1993 (open access)

Development of More Efficacious {Tc}-99m Organ Imaging Agents for Use in Nuclear Medicine by Analytical Characterization of Radiopharmaceuticals. Annual Technical Progress Report, September 1, 1992--August 31, 1993

This research program is detailed at development of more efficacious technetium-99m radiopharmaceuticals for use as imaging agents in diagnostic nuclear medicine. We seek to isolate and develop distinct site imaging agents to provide diagnostic information concerning a given pathological condition. Analytical techniques are being developed to enable complete analysis of radiopharmaceutical preparations so that individual complexes can be characterized with respect to imaging efficacy and to enable a radiopharmaceutical to be monitored after injection into a test animal to determine the species that actually accumulates in an organ to provide the image. Administration of the isolated, single most effective imaging complex, rather than a mixture of technetium-containing complexes, wi-11 minimize radiation exposure to the patient and maximize diagnostic information available to the clinician. This report specifically describes the development of capillary electrophoresis (CE) for characterizating diphosphonate skeletal imaging agents. Advances in the development of electrochemical and fiber optic sensors for Tc and Re imaging agents are described. These sensors will ultimately be capable of monitoring a specific chemical state of an imaging agent in vivo after injection into a test animal by implantation in the organ of interest.
Date: May 3, 1993
Creator: Heineman, W. R.
Object Type: Report
System: The UNT Digital Library
An analysis of three nuclear events in P-Tunnel (open access)

An analysis of three nuclear events in P-Tunnel

This report examines experimental results obtained from three P Tunnel events -- Mission Cyber, Disko Elm, and Distant Zenith. The objective of the study was to determine if there were any differences in the explosive source coupling for the three events. It was felt that Mission Cyber might not have coupled well because the ground motions recorded for that event were much lower than expected based on experience from N Tunnel. Detailed examination of the physical and chemical properties of the tuff in the vicinity of each explosion indicated only minor differences. In general, the core samples are strong and competent out to at least 60 m from each working point. Qualitative measures of core sample strength indicate that the strength of the tuff near Mission Cyber may be greater than indicated by results of static testing. Slight differences in mineralogic content and saturation of the Mission Cyber tuff were noted relative to the other two tests, but probably would not result in large differences in ground motions. Examination of scaled free-field stress and acceleration records collected by Sandia National Laboratory (SNL) indicated that Disko Elm showed the least scatter and Distant Zenith the most scatter. Mission Cyber measurements tend …
Date: May 3, 1994
Creator: Fourney, W. L.; Dick, R. D.; Taylor, S. R. & Weaver, T. A.
Object Type: Report
System: The UNT Digital Library
Proposal for the Irradiation of Cladding Studies Capsules, Series 2 (open access)

Proposal for the Irradiation of Cladding Studies Capsules, Series 2

Localized cladding instability or necking has resulted in failures of the Zr-2 cladding of rod cluster and tubular fuel elements and fuel rods in NaK filled capsules. The cause of this non-uniform cladding strain is thought to be a combination of the effects of irradiation and nonuniform cladding thickness. To determine the influence of these two factors and that of temperature on the susceptibility to failure, and to obtain data related to cladding thickness tolerances for the NPR fuel elements an irradiation experiment was designed. This experiment consisted of eighteen capsules each containing three Zr-2 clad uranium rods. Cladding thickness variations of up to 25 percent were introduced in the cladding by machining ``grooves`` longitudinally on the outer surface. The temperatures of the cladding were established by the thickness of the capsule wall. These capsules, charged in DR Reactor in October 1961, were prematurely discharged after five days irradiation because of a rupture. The cause of the rupture was established to be overheating and accelerated corrosion of the Zr-2 capsule body as a result of inadequate coolant to the capsule surface.
Date: May 3, 1962
Creator: Weber, J. W.
Object Type: Report
System: The UNT Digital Library
In-reactor rupture testing of Zircaloy-2 clad seven-rod cluster fuel elements: Interim report (open access)

In-reactor rupture testing of Zircaloy-2 clad seven-rod cluster fuel elements: Interim report

The high pressure loop installed in the 3X3 reflector position of the ETR and the associated instrumentation to detect and study failure mechanisms handled the rupture tests without difficulty. Failure of the elements was initiated by shearing off a projection on the fuel elements. The first test of the series used previously unirradiated seven-rod clusters. After the projection was sheared off the fuel elements were operated for seven hours with no failure. Failure is defined as having occurred when sufficient uranium oxide has formed to split open the cladding and release large amounts of fission products into the loop water. The second and third tests used fuel which had been irradiated to 2400 MWD/T at Hanford prior to insertion into the ETR. The second test was operated for 14 hours after the projection was sheared off--again with no failure. The third test was operated for only 33 minutes after the projection was sheared off before fission product activity in the loop water caused the test to be terminated.
Date: May 3, 1960
Creator: Call, R. L.; Green, J. W. & Kaulitz, D. C.
Object Type: Report
System: The UNT Digital Library