Diffraction grating eigenvector for translational and rotational motion (open access)

Diffraction grating eigenvector for translational and rotational motion

Future energy scaling of high-energy chirped-pulse amplification systems will benefit from the capability to coherently tile diffraction gratings into larger apertures. Design and operation of a novel, accurate alignment diagnostics for coherently tiled diffraction gratings is required for successful implementation of this technique. An invariant diffraction direction and phase for special moves of a diffraction grating is discussed, allowing simplification in the design of the coherently tiled grating diagnostics. An analytical proof of the existence of a unique diffraction grating eigenvector for translational and rotational motion which conserves the diffraction direction and diffracted wave phase is presented.
Date: July 28, 2005
Creator: Rushford, M C; Molander, W A; Nissen, J D; Jovanovic, I; Britten, J A & Barty, C J
Object Type: Article
System: The UNT Digital Library
Commercial Spent Nuclear Fuel Waste Package Misload Analysis (open access)

Commercial Spent Nuclear Fuel Waste Package Misload Analysis

The purpose of this calculation is to estimate the probability of misloading a commercial spent nuclear fuel waste package with a fuel assembly(s) that has a reactivity (i.e., enrichment and/or burnup) outside the waste package design. The waste package designs are based on the expected commercial spent nuclear fuel assemblies and previous analyses (Macheret, P. 2001, Section 4.1 and Table 1). For this calculation, a misloaded waste package is defined as a waste package that has a fuel assembly(s) loaded into it with an enrichment and/or burnup outside the waste package design. An example of this type of misload is a fuel assembly designated for the 21-PWR Control Rod waste package being incorrectly loaded into a 21-PWR Absorber Plate waste package. This constitutes a misloaded 21-PWR Absorber Plate waste package, because the reactivity (i.e., enrichment and/or burnup) of a 21-PWR Control Rod waste package fuel assembly is outside the design of a 21-PWR Absorber Plate waste package. These types of misloads (i.e., fuel assembly with enrichment and/or burnup outside waste package design) are the only types that are evaluated in this calculation. This calculation utilizes information from ''Frequency of SNF Misload for Uncanistered Fuel Waste Package'' (CRWMS M&O 1998) as …
Date: July 28, 2005
Creator: Alsaed, A.
Object Type: Report
System: The UNT Digital Library
Physical Characterization of RX-55-AE-5 a Formulation of 97.5 % 2,6-Diamino-3,5-Dinitropyrazine-1-Oxide (LLM-105) and 2.5% Viton A (open access)

Physical Characterization of RX-55-AE-5 a Formulation of 97.5 % 2,6-Diamino-3,5-Dinitropyrazine-1-Oxide (LLM-105) and 2.5% Viton A

With the use of modern tools such as molecular modeling on increasingly powerful computers, new materials can be evaluated by their structural activity relationships, SAR, and their approximate physical and chemical properties can be calculated in some cases with surprising accuracy. These new capabilities enable streamlined synthetic routes based on safety, performance and processing requirements, to name a few [1]. Current work includes both understanding properties of old explosives and measuring properties of new ones. The necessity to know and understand the properties of energetic materials is driven by the need to improve performance and enhance stability to various stimuli, such as thermal, friction and impact insult. This review will concentrate on the physical properties of RX-55-AE-5, which is formulated from heterocyclic explosive, 2,6-diamino-3,5-dinitropyrazine-1-oxide, LLM-105, and 2.5% Viton A. Differential scanning calorimetry, DSC, was used to measure a specific heat capacity, C{sub p}, of {approx} 0.950 J/g {center_dot} C, and a thermal conductivity, {kappa}, of {approx} 0.160 W/m {center_dot} C. The Lawrence Livermore National Laboratory (LLNL) code Kinetics05 and the Advanced Kinetics and Technology Solutions (AKTS) code Thermokinetics were both used to calculate Arrhenius kinetics for decomposition of LLM-105. Both obtained an activation energy barrier E {approx} 180 kJ mol{sup …
Date: July 28, 2005
Creator: Weese, R K; Burnham, A K; Turner, H C & Tran, T D
Object Type: Article
System: The UNT Digital Library
Blend Down Monitoring System Fissile Mass Flow Monitor and its Implementation at the Siberian Chemical Enterprise, Seversk, Russia (open access)

Blend Down Monitoring System Fissile Mass Flow Monitor and its Implementation at the Siberian Chemical Enterprise, Seversk, Russia

In this paper the implementation plans and preparations for installation of the Fissile Mass Flow Monitor (FMFM) equipment at the Siberian Chemical Enterprise (SChE), Seversk, Russia, are presented. The FMFM, developed by Oak Ridge National Laboratory, is part of the Blend Down Monitoring System (BDMS) for the U.S. Department of Energy Highly Enriched Uranium (HEU) Transparency Implementation Program. The BDMS provides confidence to the United States that the Russian nuclear facilities supplying the lower assay ({approx}4%) product low enriched uranium (PLEU) to the United States from down-blended weapon-grade HEU are meeting the nonproliferation goals of the government-to-government HEU purchase agreement signed between the Russian Federation and the United States in 1993. The first BDMS has been operational at Ural Electrochemical Integrated Plant, Novouralsk, since February 1999. The second BDMS has been operational at Electro Chemical Plant, Zelenogorsk, since March 2003. These systems are successfully providing HEU transparency data to the United States. The third BDMS was successfully installed on the HEU down-blending tee in the SChE Enrichment Plant in October 2004. The FMFM makes use of a set of thermalized {sup 252}Cf spontaneous neutron sources for modulated fission activation of the UF{sub 6} gas stream for measuring the {sup 235}U …
Date: July 28, 2005
Creator: Uckan, T
Object Type: Report
System: The UNT Digital Library
Southern Ocean Iron Experiment (SOFex) (open access)

Southern Ocean Iron Experiment (SOFex)

The Southern Ocean Iron Experiment (SOFeX) was an experiment decades in the planning. It's implementation was among the most complex ship operations that SIO has been involved in. The SOFeX field expedition was successful in creating and tracking two experimentally enriched areas of the Southern Ocean, one characterized by low silicic acid, one characterized by high silicic acid. Both experimental sites were replete with abundant nitrate. About 100 scientists were involved overall. The major findings of this study were significant in several ways: (1) The productivity of the southern ocean is limited by iron availability. (2) Carbon uptake and flux is therefore controlled by iron availability (3) In spite of low silicic acid, iron promotes non-silicious phytoplankton growth and the uptake of carbon dioxide. (4) The transport of fixed carbon from the surface layers proceeds with a C:N ratio that would indicate differential remineralization of nitrogen at shallow depths. (5) These finding have major implications for modeling of carbon export based on nitrate utilization. (6) The general results of the experiment indicate that, beyond other southern ocean enrichment experiments, iron inputs have a much wider impact of productivity and carbon cycling than previously demonstrated. Scientific presentations: Coale, K., Johnson, K, …
Date: July 28, 2005
Creator: Coale, Kenneth H.
Object Type: Article
System: The UNT Digital Library
Final Technical Report: Nanostructured Shape Memory Alloys (open access)

Final Technical Report: Nanostructured Shape Memory Alloys

With this grant we explored the properties that result from combining the effects of nanostructuring and shape memory using both experimental and theoretical approaches. We developed new methods to make nanostructured NiTi by melt-spinning and cold rolling fabrication strategies, which elicited significantly different behavior. A template synthesis method was also used to created nanoparticles. In order to characterize the particles we created, we developed a new magnetically-assisted particle manipulation technique to manipulate and position nanoscale samples for testing. Beyond characterization, this technique has broader implications for assembly of nanoscale devices and we demonstrated promising applications for optical switching through magnetically-controlled scattering and polarization capabilities. Nanoparticles of nickel-titanium (NiTi) shape memory alloy were also produced using thin film deposition technology and nanosphere lithography. Our work revealed the first direct evidence that the thermally-induced martensitic transformation of these films allows for partial indent recovery on the nanoscale. In addition to thoroughly characterizing and modeling the nanoindentation behavior in NiTi thin films, we demonstrated the feasibility of using nanoindentation on an SMA film for write-read-erase schemes for data storage.
Date: July 28, 2005
Creator: Crone, Wendy; Drugan, Walter; Ellis, Arthur & Perepezko, John
Object Type: Report
System: The UNT Digital Library
Ultrahigh Sensitivity Heavy Noble Gas Detectors for Long-Term Monitoring and for Monitoring Air (open access)

Ultrahigh Sensitivity Heavy Noble Gas Detectors for Long-Term Monitoring and for Monitoring Air

The primary objective of this research project is to develop heavy noble gas (krypton, xenon, and radon) detectors for (1) long-term monitoring of transuranic waste, spent fuel, and other uranium and thorium bearing wastes and (2) alpha particle air monitors that discriminate between radon emissions and other alpha emitters. DOE needs that are addressed by this project include improved long-term monitoring capability and improved air monitoring capability during remedial activities. Successful development and implementation of the proposed detection systems could significantly improve current capabilities with relatively simple and inexpensive equipment.
Date: July 28, 2005
Creator: Valentine, John D.
Object Type: Report
System: The UNT Digital Library
Development of Advanced Electrochemical Emission Spectroscopy for Monitoring Corrosion in Simulated DOE Liquid Waste (open access)

Development of Advanced Electrochemical Emission Spectroscopy for Monitoring Corrosion in Simulated DOE Liquid Waste

The different tasks that have been carried out under the current program are as follows: (1) Theoretical and experimental assessment of general corrosion of iron/steel in borate buffer solutions by using electrochemical impedance spectroscopy (EIS), ellipsometry and XPS techniques; (2) Development of a damage function analysis (DFA), which would help in predicting the accumulation of damage due to pitting corrosion in an environment prototypical of DOE liquid waste systems; (3) Experimental measurement of crack growth rate, acoustic emission signals, and coupling currents for fracture in carbon and low alloy steels as functions of mechanical (stress intensity), chemical (conductivity), electrochemical (corrosion potential, ECP), and microstructural (grain size, precipitate size, etc) variables in a systematic manner, with particular attention being focused on the structure of the noise in the current and its correlation with the acoustic emissions; (4) Development of fracture mechanisms for carbon and low alloy steels that are consistent with the crack growth rate, coupling current data and acoustic emissions; (5) Inserting advanced crack growth rate models for SCC into existing deterministic codes for predicting the evolution of corrosion damage in DOE liquid waste storage tanks; (6) Computer simulation of the anodic and cathodic activity on the surface of the …
Date: July 28, 2005
Creator: Macdonald, Digby; Marx, Brian; Soundararajan, Balaji & Smith, Morgan
Object Type: Report
System: The UNT Digital Library
ISENTROPIC COMPRESSION DATA ON LX-04 EXPLOSIVE AT 150?C USING THE Z ACCELERATOR (open access)

ISENTROPIC COMPRESSION DATA ON LX-04 EXPLOSIVE AT 150?C USING THE Z ACCELERATOR

Isentropic compression data was collected on LX-04 explosive (85% HMX and 15% Viton by weight) at 150 C using the Sandia National Laboratories Z accelerator facility. A ramp compression wave was applied to the explosive samples mounted on aluminum panels with VISAR interferometry measuring the sample and backing window interface velocity. Heating was obtained by wrapping band heaters around a thermal mass attached to each panel and temperatures were recorded by thermocouples at several locations on the panel. This work will outline the methods used, discuss the VISAR interface velocities, and present the preliminary data obtained on heated LX-04. These results demonstrate the ability to perform experiments on preheated samples to obtain isentrope data.
Date: July 28, 2005
Creator: Hare, D E; Vandersall, K S; Garcia, F; Davis, J; Hall, C & Forbes, J W
Object Type: Article
System: The UNT Digital Library
Photon Collider Technology Overview (open access)

Photon Collider Technology Overview

The photon collider option requires the generation of large amounts of laser power to drive the Compton scattering. The selection of the superconducting RF for the baseline of the ILC makes a recirculating solution attractive. A baseline for a recirculating cavity for the photon collider has been developed by a team [1, 2] at DESY/Zeuthen and the Max Born Institute. Similar cavities at much lower scale are being developed for laser wire and Compton polarimeter applications. The current status of the laser technology and a proposal for future development are reviewed. The impact of the {gamma}{gamma} experiment on the accelerator and detector is also discussed.
Date: July 28, 2005
Creator: Gronberg, J
Object Type: Article
System: The UNT Digital Library
Glass and glass-derivative seals for use in energy-efficient fuel cells and lamps (open access)

Glass and glass-derivative seals for use in energy-efficient fuel cells and lamps

For solid oxide fuel cells (SOFC), a series of 18 sealing glasses have been prepared and characterized. From the whole design space, several glasses were ''downselected'' and studied in detail to describe their behaviors in simulated fuel cell environments. One of the glasses was found to outperform all others, including the well-known G18 sealant developed at Pacific Northwest National Laboratory. The new glass composition showed lower bulk electrical conductivity, excellent sealing and wetting behavior when sealing under applied load, and qualitatively superior performance when exposed to wet hydrogen for 800 hours. Traditional melting was used to prepare all of the glasses that were studied in detail. The sol-gel approach was used to synthesize several compositions, but it was found that the glasses crystallized very rapidly during heating, precluding sealing. The glass characterization included measurements of the viscosity and thermal expansion of the glasses, as well as the thermal expansion of the partly crystalline glass ceramics. In addition, the wetting and sintering behavior of all glasses has been measured, as well as the crystallization behavior. The time and temperature at which crystalline phases form from the glasses has been determined for all of the glasses. Each glass ceramic contains at least …
Date: July 28, 2005
Creator: Misture, Scott; Varshineya, Arun; Hall, Matthew; DeCarr, Sylvia & Bancheri, Steve
Object Type: Report
System: The UNT Digital Library
Molecular Recognition of DNA Damage Sites by Apurinic/Apyrimidinic Endonucleases (open access)

Molecular Recognition of DNA Damage Sites by Apurinic/Apyrimidinic Endonucleases

The DNA repair/redox factor AP endonuclease 1 (APE1) is a multifunctional protein which is known to to be essential for DNA repair activity in human cells. Structural/functional analyses of the APE activity is thus been an important research field to assess cellular defense mechanisms against ionizing radiation.
Date: July 28, 2005
Creator: Braun, W. A.
Object Type: Report
System: The UNT Digital Library
Advancements in time-resolved x-ray laser induced time-of-flight photoelectron spectroscopy (open access)

Advancements in time-resolved x-ray laser induced time-of-flight photoelectron spectroscopy

Time-resolved soft x-ray photoelectron spectroscopy is used to probe the non-steady-state evolution of the valence band electronic structure of laser heated ultra-thin (50 nm) metal foils and bulk semiconductors. Single-shot soft x-ray laser induced time-of-flight photoelectron spectroscopy with picosecond time resolution was used in combination with optical measurements of the disassembly dynamics that have shown the existence of a metastable liquid phase in fs-laser heated metal foils persisting 4-5 ps. This metastable phase is studied using a 527 nm wavelength 400 fs laser pulse containing 0.3-2.5 mJ laser energy focused in a large 500 x 700 {micro}m{sup 2} spot to create heated conditions of 0.2-1.8 x 10{sup 12} W cm{sup -2} intensity. The unique LLNL COMET compact tabletop soft x-ray laser source provided the necessary high photon flux, highly monoenergetic, picosecond pulse duration, and coherence for observing the evolution of changes in the valence band electronic structure of laser heated metals and semiconductors with picosecond time resolution. This work demonstrates the continuing development of a powerful new technique for probing reaction dynamics and changes of local order on surfaces on their fundamental timescales including phenomena such as non-thermal melting, chemical bond formation, intermediate reaction steps, and the existence of transient …
Date: July 28, 2005
Creator: Nelson, A J; Dunn, J; Widmann, K; Ao, T; Ping, Y; Hunter, J et al.
Object Type: Article
System: The UNT Digital Library
Solving Fluid Flow Problems on Moving and Adaptive Overlapping Grids (open access)

Solving Fluid Flow Problems on Moving and Adaptive Overlapping Grids

Solution of fluid dynamics problems on overlapping grids will be discussed. An overlapping grid consists of a set of structured component grids that cover a domain and overlap where they meet. Overlapping grids provide an effective approach for developing efficient and accurate approximations for complex, possibly moving geometry. Topics to be addressed include the reactive Euler equations, the incompressible Navier-Stokes equations and elliptic equations solved with a multigrid algorithm. Recent developments coupling moving grids and adaptive mesh refinement and preliminary parallel results will also be presented.
Date: July 28, 2005
Creator: Henshaw, W
Object Type: Article
System: The UNT Digital Library