Measurement of 150-Sm(n,2ngammai) 149-Sm cross sections between threshold and 20 MeV (open access)

Measurement of 150-Sm(n,2ngammai) 149-Sm cross sections between threshold and 20 MeV

Absolute partial {gamma}-ray cross sections for the production of discrete {gamma}-rays from the reaction {sup 150}Sm(n,2n{gamma}{sub i}){sup 149}Sm were measured using the GEANIE {gamma}-ray spectrometer coupled with the intense white neutron source at WNR/LANSCE. The measurements were made for incident neutron energies between threshold (8.04 MeV) and 20 MeV. The partial cross sections for 21 {gamma}-rays were extracted from the data. Of these, 17 were compared to calculations performed using the enhanced Hauser-Feshbach code STAPRE. The partial {gamma}-ray cross sections of the observed parallel decay paths to the ground state were summed, forming a lower bound for the (n,2n) reaction channel. A combination of theory and experiment was then used to deduce the (n,2n) reaction channel cross section.
Date: August 2, 2004
Creator: Cooper, J.; Becker, J.; Dashdorj, D.; Dietrich, F. S.; Garrett, P.; Hoffman, R. et al.
Object Type: Report
System: The UNT Digital Library
Analytic Model of Reactive Flow (open access)

Analytic Model of Reactive Flow

A simple analytic model allows prediction of rate constants and size effect behavior before a hydrocode run if size effect data exists. At infinite radius, it defines not only detonation velocity but also average detonation rate, pressure and energy. This allows the derivation of a generalized radius, which becomes larger as the explosive becomes more non-ideal. The model is applied to near-ideal PBX 9404, in-between ANFO and most non-ideal AN. The power of the pressure declines from 2.3, 1.5 to 0.8 across this set. The power of the burn fraction, F, is 0.8, 0 and 0, so that an F-term is important only for the ideal explosives. The size effect shapes change from concave-down to nearly straight to concave-up. Failure is associated with ideal explosives when the calculated detonation velocity turns in a double-valued way. The effect of the power of the pressure may be simulated by including a pressure cutoff in the detonation rate. The models allows comparison of a wide spectrum of explosives providing that a single detonation rate is feasible.
Date: August 2, 2004
Creator: Souers, P C & Vitello, P
Object Type: Article
System: The UNT Digital Library
Diboson production cross-sections at square root s = 1.96 TeV (open access)

Diboson production cross-sections at square root s = 1.96 TeV

Recent results of W{gamma}, Z{gamma} and WW cross-section measurements in the electron and muon channels are reported from p{bar p} collisions at {radical}s = 1.96 TeV recorded by the CDF and D0 collaborations. Total cross-sections and kinematic distributions are found to be consistent with Standard Model expectations.
Date: August 2, 2004
Creator: Robson, A.
Object Type: Article
System: The UNT Digital Library
New Correction Procedure for X-Ray Spectroscopic Fluorescence Data: Simulations and Experiment. (open access)

New Correction Procedure for X-Ray Spectroscopic Fluorescence Data: Simulations and Experiment.

X-ray fluorescence spectroscopy is a widely used method for determining the electronic configuration and local structure of dilute species with high sensitivity. In the dilute limit, and for thin films, the X-ray fluorescence signal is directly proportional to the atomic sub-shell absorption coefficient. However, for concentrated samples, the well-documented self-absorption effect often leads to the severe suppression of XANES (X-ray Absorption Near-Edge Structure) and EXAFS (Extended X-ray Absorption Fine-Structure) amplitudes. Thus to recover the real value of the sub-shell absorption coefficient, it is important to apply correction procedures to the measured fluorescence spectra. In this paper, we describe a new straightforward method to correct for self-absorption effects (the difference in the measured fluorescence signal compared to that of the true sub-shell photoabsorption coefficient) in XANES and EXAFS fluorescence measurements. Using a variety of sample and detector configurations, this method is used to extract the sub-shell absorption coefficient on elemental nickel and thick single-crystals of Gd{sub 3}Ga{sub 5}O{sub 12} and LaAlO{sub 3}.
Date: August 2, 2004
Creator: Ablett, J. M.; Woicik, J. C. & Kao, C. C.
Object Type: Article
System: The UNT Digital Library
Strong-strong beam-beam simulation on parallel computer (open access)

Strong-strong beam-beam simulation on parallel computer

The beam-beam interaction puts a strong limit on the luminosity of the high energy storage ring colliders. At the interaction points, the electromagnetic fields generated by one beam focus or defocus the opposite beam. This can cause beam blowup and a reduction of luminosity. An accurate simulation of the beam-beam interaction is needed to help optimize the luminosity in high energy colliders.
Date: August 2, 2004
Creator: Qiang, Ji
Object Type: Article
System: The UNT Digital Library
Scaled Opposite Spin Second Order Moller-Plesset Correlation Energy: An Economical Electronic Structure Method (open access)

Scaled Opposite Spin Second Order Moller-Plesset Correlation Energy: An Economical Electronic Structure Method

A simplified approach to treating the electron correlation energy is suggested in which only the alpha-beta component of the second order Moller-Plesset energy is evaluated, and then scaled by an empirical factor which is suggested to be 1.3. This scaled opposite spin second order energy (SOS-MP2) yields results for relative energies and derivative properties that are statistically improved over the conventional MP2 method. Furthermore, the SOS-MP2 energy can be evaluated without the 5th order computational steps associated with MP2 theory, even without exploiting any spatial locality. A 4th order algorithm is given for evaluating the opposite spin MP2 energy using auxiliary basis expansions, and a Laplace approach, and timing comparisons are given.
Date: August 2, 2004
Creator: Jung, Yousung; Lochan, Rohini C.; Dutoi, Anthony D. & Head-Gordon, Martin
Object Type: Article
System: The UNT Digital Library
Energy efficiency standards for residential and commercial equipment: Additional opportunities (open access)

Energy efficiency standards for residential and commercial equipment: Additional opportunities

Energy efficiency standards set minimum levels of energy efficiency that must be met by new products. Depending on the dynamics of the market and the level of the standard, the effect on the market for a given product may be small, moderate, or large. Energy efficiency standards address a number of market failures that exist in the buildings sector. Decisions about efficiency levels often are made by people who will not be responsible for the energy bill, such as landlords or developers of commercial buildings. Many buildings are occupied for their entire lives by very temporary owners or renters, each unwilling to make long-term investments that would mostly reward subsequent users. And sometimes what looks like apathy about efficiency merely reflects inadequate information or time invested to evaluate it. In addition to these sector-specific market failures, energy efficiency standards address the endemic failure of energy prices to incorporate externalities. In the U.S., energy efficiency standards for consumer products were first implemented in California in 1977. National standards became effective starting in 1988. By the end of 2001, national standards were in effect for over a dozen residential appliances, as well as for a number of commercial sector products. Updated standards …
Date: August 2, 2004
Creator: Rosenquist, Greg; McNeil, Michael; Iyer, Maithili; Meyers, Steve & McMahon, Jim
Object Type: Report
System: The UNT Digital Library
New high performance hybrid magnet plates for DNA separation andbio-technology applications (open access)

New high performance hybrid magnet plates for DNA separation andbio-technology applications

A new class of magnet plates for biological and industrial applications has recently been developed at the D.O.E. Joint Genome Institute and Lawrence Berkeley National Laboratory (JGI/LBNL). These devices utilize hybrid technology that combines linear permanent magnet material and ferromagnetic material to produce significantly higher fields and gradients than currently available commercial magnet plates. These hybrid structures incorporate ferromagnetic poles that can be easily shaped to produce complex field distributions for specialized applications. The higher maximum fields and strong gradients of the hybrid structures result in greater holding forces on magnetized targets that are being processed as well as faster draw-down. Current development versions of these magnet plates have exhibited maximum fields in excess of 9000.0 Gauss. The design of these structures is easily scalable to allow for field increases to significantly above 1.0 tesla (10000.0gauss). Author's note: 11000.0 Gauss peak fields have been achieved as of January 2005.
Date: August 2, 2004
Creator: Humphries, David; Pollard, Martin; Elkin, Chris; Petermann, Karl; Reiter, Charles & Cepeda, Mario
Object Type: Report
System: The UNT Digital Library
Sludge Batch 3 Qualification in the SRTC Shielded Cells (open access)

Sludge Batch 3 Qualification in the SRTC Shielded Cells

The Defense Waste Processing Facility (DWPF) requested that a radioactive demonstration of the next batch of sludge slurry (Sludge Batch 3) be completed in the Shielded Cells Facility of the Savannah River Technology Center (SRTC). Sludge Batch 3 (SB3) consists of the heel in Tank 51, which included Plutonium (Pu) and Americium/Curium (Am/Cm); sludge slurry from Tank 7 (including sludge transferred into Tank 7 from Tanks 18 and 19); additional Pu transferred from H Canyon; a Neptunium (Np) transfer also from H Canyon; and the remaining Sludge Batch 2 material in Tank 40. Because the current contents of Tank 40 (Sludge Batch 2) have already been qualified, this qualification work did not include the contribution of Tank 40. Documented in this report are: preparation of a SB3 slurry using a Tank 51 sample from June 2003; a demonstration of the DWPF Sludge Receipt and Adjustment Tank (SRAT) cycle using SB3 slurry; a demonstration of the DWPF Slurry Mix Evaporator (SME) cycle using SRAT product; glass fabrication and subsequent chemical durability evaluation using SB3 material; and evaluation of adding formic acid to the SME cycle product.
Date: August 2, 2004
Creator: PAREIZS, JOHNM.
Object Type: Report
System: The UNT Digital Library
Supplement Analysis for the Watershed Management Program EIS - Idaho Model Watershed Habitat Projects - L-9 Irrigation Diversion Modification (open access)

Supplement Analysis for the Watershed Management Program EIS - Idaho Model Watershed Habitat Projects - L-9 Irrigation Diversion Modification

The Bonneville Power Administration is proposing to fund a fish passage improvement project at the L-9 diversion on the Lemhi River in Lemhi County, Idaho with the Lemhi Soil and Water Conservation District. The project proposes to replace the existing rock push-up irrigation diversion dam with a single rock weir that will incorporate a geotextile membrane to create a permanent diversion. The new weir will be a v-shaped vortex weir with a six-foot wide notch for fish passage. In addition, a ramp flume will be constructed in the diversion canal between the headgate and existing fish screen to provide for water measurement. The new diversion will provide better water delivery/control and improved passage for adult and juvenile resident and anadromous fish.
Date: August 2, 2004
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Surface-layer Turbulence During a Frontal Passage (open access)

Surface-layer Turbulence During a Frontal Passage

None
Date: August 2, 2004
Creator: Piper, M & Lundquist, J K
Object Type: Article
System: The UNT Digital Library
Neuroscience and Accelerator Mass Spectrometry (open access)

Neuroscience and Accelerator Mass Spectrometry

Accelerator mass spectrometry (AMS) is a mass spectrometric method for quantifying rare isotopes. It has had great impact in geochronology and archaeology and is now being applied in biomedicine. AMS measures radioisotopes such as {sup 3}H, {sup 14}C, {sup 26}Al, {sup 36}Cl and {sup 41}Ca, with zepto- or attomole sensitivity and high precision and throughput, enabling safe human pharmacokinetic studies involving: microgram doses, agents having low bioavailability, or toxicology studies where administered doses must be kept low (<1 {micro}g/kg). It is used to study long-term pharmacokinetics, to identify biomolecular interactions, to determine chronic and low-dose effects or molecular targets of neurotoxic substances, to quantify transport across the blood-brain barrier and to resolve molecular turnover rates in the human brain on the timescale of decades. We will here review how AMS is applied in neurotoxicology and neuroscience.
Date: August 2, 2004
Creator: Palmblad, M. N.; Buchholz, B. A.; Hillegonds, D. J. & Vogel, J. S.
Object Type: Article
System: The UNT Digital Library
ELECTRON INJECTORS FOR NEXT GENERATION X-RAY SOURCES. (open access)

ELECTRON INJECTORS FOR NEXT GENERATION X-RAY SOURCES.

Next generation x-ray sources require very high-brightness electron beams that are typically at or beyond the present state-of-the-art, and thus place stringent and demanding requirements upon the electron injector parameters. No one electron source concept is suitable for all the diverse applications envisaged, which have operating characteristics ranging from high-average-current, quasi-CW, to high-peak-current, single-pulse electron beams. Advanced Energy Systems, in collaboration with various partners, is developing several electron injector concepts for these x-ray source applications. The performance and design characteristics of five specific RF injectors, spanning ''L'' to ''X''-band, normal-conducting to superconducting, and low repetition rate to CW, which are presently in various stages of design, construction or testing, is described. We also discuss the status and schedule of each with respect to testing.
Date: August 2, 2004
Creator: Bluem, H.; Ben-Zvi, Ilan; Srinivasan-Rao, T. & AL., ET
Object Type: Article
System: The UNT Digital Library
Data vs Monte Carlo Comparison of NN1 Detector (open access)

Data vs Monte Carlo Comparison of NN1 Detector

In this note, we demonstrate agreement between data and Geant4 simulations of the NN1 double-sided germanium detector using a {sup 22}Na source.
Date: August 2, 2004
Creator: Lange, D; Wright, D; Burks, M & Jordan, E
Object Type: Report
System: The UNT Digital Library
DAKTOOLS (open access)

DAKTOOLS

None
Date: August 2, 2004
Creator: Tipton, P & Brandon, S
Object Type: Article
System: The UNT Digital Library
Adaptive 4-8 Texture Hierarchies (open access)

Adaptive 4-8 Texture Hierarchies

We address the texture level-of-detail problem for extremely large surfaces such as terrain during real-time, view-dependent rendering. A novel texture hierarchy is introduced based on 4-8 refinement of raster tiles, in which the texture grids in effect rotate 45 degrees for each level of refinement. This hierarchy provides twice as many levels of detail as conventional quad-tree-style refinement schemes such as mipmaps, and thus provides per-pixel view-dependent filtering that is twice as close to the ideal cutoff frequency for an average pixel. Because of this more gradual change in low-pass filtering, and due to the more precise emulation of the ideal cutoff frequency, we find in practice that the transitions between texture levels of detail are not perceptible. This allows rendering systems to avoid the complexity and performance costs of per-pixel blending between texture levels of detail. The 4-8 texturing scheme is integrated into a variant of the Real-time Optimally Adapting Meshes (ROAM) algorithm for view-dependent multiresolution mesh generation. Improvements to ROAM included here are: the diamond data structure as a streamlined replacement for the triangle bintree elements, the use of low-pass-filtered geometry patches in place of individual triangles, integration of 4-8 textures, and a simple out-of-core data access mechanism …
Date: August 2, 2004
Creator: Hwa, L M; Duchaineau, M A & Joy, K I
Object Type: Article
System: The UNT Digital Library
Quantitation of Binding, Recovery and Desalting Efficiency in Solid Phase Extraction Micropipette Tips (open access)

Quantitation of Binding, Recovery and Desalting Efficiency in Solid Phase Extraction Micropipette Tips

Micropipette-tip solid phase extraction systems are common in proteomic analyses for desalting and concentrating samples for mass spectrometry, removing interferences, and increasing sensitivity. These systems are inexpensive, disposable, and highly efficient. Here we show micropipette-tip solid phase extraction is a direct sample preparation method for {sup 14}C-accelerator mass spectrometry (AMS), removing salts or reagent from labeled macromolecules. We compared loading, recovery and desalting efficiency in commercially available SPE micro-tips using {sup 14}C-labeled peptides and proteins, AMS, and alpha spectrometry ion energy loss quantitation. The polypropylene in the tips was nearly {sup 14}C-free and simultaneously provided low-background carrier for AMS. The silica material did not interfere with the analysis. Alpha spectrometry provided an absolute measurement of desalting efficiency.
Date: August 2, 2004
Creator: Palmblad, M N & Vogel, J S
Object Type: Article
System: The UNT Digital Library
Heterodyning Time Resolution Boosting for Velocimetry and Reflectivity Measurements (open access)

Heterodyning Time Resolution Boosting for Velocimetry and Reflectivity Measurements

A theoretical technique is described for boosting the temporal resolving power by several times, of detectors such as streak cameras in experiments that measure light reflected from or transmitted through a target, including velocity interferometer (VISAR) measurements. This is a means of effectively increasing the number of resolvable time bins in a streak camera record past the limit imposed by input slit width and blur on the output phosphor screen. The illumination intensity is modulated sinusoidally at a frequency similar to the limiting time response of the detector. A heterodyning effect beats the high frequency science signal down a lower frequency beat signal, which is recorded together with the conventional science signal. Using 3 separate illuminating channels having different phases, the beat term is separated algebraically from the conventional signal. By numerically reversing the heterodyning, and combining with the ordinary signal, the science signal can be reconstructed to better effective time resolution than the detector used alone. The effective time resolution can be approximately halved for a single modulation frequency, and further decreased inversely proportional to the number of independent modulation frequencies employed.
Date: August 2, 2004
Creator: Erskine, D J
Object Type: Article
System: The UNT Digital Library
Precision Electroweak Measurements and the Higgs Mass. (open access)

Precision Electroweak Measurements and the Higgs Mass.

The utility of precision electroweak measurements for predicting the Standard Model Higgs mass via quantum loop effects is discussed. Current constraints from m{sub w} and sin{sup 2} {theta}{sub w} (m{sub z}){sub {ovr MS}} imply a relatively light Higgs {approx}< 154 GeV which is consistent with Supersymmetry expectations. The existence of Supersymmetry is further suggested by a discrepancy between experiment and theory for the muon anomalous magnetic moment. Constraints from precision studies on other types of ''New Physics'' are also briefly described.
Date: August 2, 2004
Creator: Marciano, William J.
Object Type: Article
System: The UNT Digital Library
Fabrication and Metrology of Micro-Scale Sinusoidal Surfaces in Polymer Workpiece Materials (open access)

Fabrication and Metrology of Micro-Scale Sinusoidal Surfaces in Polymer Workpiece Materials

This study investigates the fabrication of precision, micro-scale sinusoidal surfaces in polymer workpiece materials and discusses methods to quantitatively characterize these surfaces. These precision sinusoidal surfaces are an important feature in a mesoscale assembly that will be used as part of a physics experiment. The experiment will study the formation of Rayleigh Taylor instabilities and requires a sinusoidal surface with an amplitude of 2.5 {micro}m and a wavelength of 70.7 {micro}m in both the x- and y-directions. The sinusoids must have sub-{micro}m form accuracy with a surface finish on the order of 100 nm, and they must be produced in a workpiece consisting of adjacent pieces of polyimide and iodine-doped polystyrene, a portion of which is illustrated in Figure 1.
Date: August 2, 2004
Creator: Bono, M J & Hibbard, R L
Object Type: Article
System: The UNT Digital Library
Release Data Package for the 2004 Composite Analysis (open access)

Release Data Package for the 2004 Composite Analysis

This data package contains all the key parameter data necessary for implementation of the Release Module to conduct the 2004 Composite Analysis. A composite analysis is required by DOE Order 435.1 to ensure public safety through the management of active and planned low-level radioactive waste disposal facilities associated with Hanford.
Date: August 2, 2004
Creator: Riley, Robert G. & Lopresti, Charles A.
Object Type: Report
System: The UNT Digital Library
DISTINGUISHING SPONTANEOUS FISSION NEUTRONS FROM COSMIC-RAY BACKGROUND. (open access)

DISTINGUISHING SPONTANEOUS FISSION NEUTRONS FROM COSMIC-RAY BACKGROUND.

We have measured the neutron spectra of cosmic-rays and a spontaneous fission emitting source (Cf-252) using a neutron double scatter spectrometer. The energy range of measurements was 0.1-10 MeV where the spectrometer efficiency is determined to be up to 8.7% depending on the separation between detection planes. Our cosmic-ray neutron spectrum measurement is in good agreement with the sea-level data reported by Goldhagen and his co-workers. In the energy range 0.1-1.0 MeV, the cosmic-ray and Cf-252 spectra are different and separable. This difference is expected from the applicable models that describe the phenomena, ''equilibrium slowing down'' (cosmic-rays) and ''Maxwellian kinetic temperature'' emission (spontaneous fission). We show that >80% of Cf-252 neutrons and <25% of cosmic-ray related neutrons are emitted in this energy range of measurement, and conclude that neutron spectroscopy provides effective ways to distinguish a fission source from the cosmic-ray background.
Date: August 2, 2004
Creator: FORMAN,L.
Object Type: Article
System: The UNT Digital Library
Fissile Mass Flow Monitor Gamma Ray Detector System Designed for Large-Size Process Pipes (open access)

Fissile Mass Flow Monitor Gamma Ray Detector System Designed for Large-Size Process Pipes

None
Date: August 2, 2004
Creator: Uckan, T.
Object Type: Report
System: The UNT Digital Library
Carbon Sequestration on Surface Mine Lands Quarterly Report (open access)

Carbon Sequestration on Surface Mine Lands Quarterly Report

The April-June 2004 quarter was dedicated to the establishment of monitoring systems for all the new research areas. Hydrology and water quality monitoring continues to be conducted on all areas as does weather data pertinent to the research. Studies assessing specific questions pertaining to carbon flux has been established and the invasion of the vegetation by small mammals is being quantified. The approval of two experimental practices associated with this research by the United States Office of Surface Mining was a major accomplishment during this period of time. These experimental practices will eventually allow for tree planting on long steep slopes with loose grading systems and for the use of loose dumped spoil on mountain top removal areas with no grading in the final layer of rooting material for tree establishment.
Date: August 2, 2004
Creator: Graves, Donald H.; Barton, Christopher; Sweigard, Richard & Warner, Richard
Object Type: Report
System: The UNT Digital Library