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Precise predictions for B -> Xs l+ l- in the large q2 region (open access)

Precise predictions for B -> Xs l+ l- in the large q2 region

The inclusive B -> Xs l+ l- decay rate in the large q2 region (q2> m_psi'2) receives significant nonperturbative corrections. The resulting uncertainties can be drastically reduced by normalizing the rate to the B -> Xu l nu rate with the same q2 cut, which allows for much improved tests of short distance physics. We calculate this ratio, including the order 1/m_b3 nonperturbative corrections and the analytically known NNLO perturbative corrections. Since in the large q2 region an inclusive measurement may be feasible via a sum over exclusive states, our results could be useful for measurements at LHCb and possibly for studies of B -> Xd l+ l-.
Date: July 12, 2007
Creator: Ligeti, Zoltan; Ligeti, Zoltan & Tackmann, Frank J.
System: The UNT Digital Library
SRNL Emergency Response Capability for Atmospheric Contaminant Releases (open access)

SRNL Emergency Response Capability for Atmospheric Contaminant Releases

Emergency response to an atmospheric release of chemical or radiological contamination is enhanced when plume predictions, field measurements, and real-time weather information are integrated into a geospatial framework. The Weather Information and Display (WIND) System at Savannah River National Laboratory (SRNL) utilizes such an integrated framework. The rapid availability of predictions from a suite of atmospheric transport models within this geospatial framework has proven to be of great value to decision makers during an emergency involving an atmospheric contaminant release.
Date: July 12, 2006
Creator: Koffman, L.; Chuck Hunter, C.; Robert Buckley, R. & Robert Addis, R.
System: The UNT Digital Library
ANOLE Portable Radiation Detection System Field Test and Evaluation Campaign (open access)

ANOLE Portable Radiation Detection System Field Test and Evaluation Campaign

Handheld, backpack, and mobile sensors are elements of the Global Nuclear Detection System for the interdiction and control of illicit radiological and nuclear materials. They are used by the U.S. Department of Homeland Security (DHS) and other government agencies and organizations in various roles for border protection, law enforcement, and nonproliferation monitoring. In order to systematically document the operational performance of the common commercial off-the-shelf portable radiation detection systems, the DHS Domestic Nuclear Detection Office conducted a test and evaluation campaign conducted at the Nevada Test Site from January 18 to February 27, 2006. Named “Anole,” it was the first test of its kind in terms of technical design and test complexities. The Anole test results offer users information for selecting appropriate mission-specific portable radiation detection systems. The campaign also offered manufacturers the opportunity to submit their equipment for independent operationally relevant testing to subsequently improve their detector performance. This paper will present the design, execution, and methodologies of the DHS Anole portable radiation detection system test campaign.
Date: July 12, 2007
Creator: Hodge, Chris A.
System: The UNT Digital Library
Proceedings of the Plutonium Futures ? The Science 2006 Conference (open access)

Proceedings of the Plutonium Futures ? The Science 2006 Conference

Plutonium Futures--The Science 2006 provided opportunities to examine present knowledge of the chemical and physical properties of plutonium and other actinides in complex media and materials; to discuss the current and emerging science (chemistry, physics, materials science, nuclear science, and environmental effects) of plutonium and actinides relevant to enhancing global nuclear security; and to exchange ideas. This international conference also provided a forum for illustrating and enhancing capabilities and interests, and assessing issues in these areas. U.S. and international scientists, engineers, faculty, and students from universities, national laboratories, and DOE's nuclear complex were encouraged to participate and make technical contributions. The Conference ran from Sunday, July 9th through Thursday, July 13th. A popular aspect of the conference was the opening tutorial session on Sunday afternoon intended for students and scientists new to the area of plutonium research. The tutorial was well attended by novices and veterans alike, and featured such diverse topics as; plutonium metallurgy, plutonium in the environment, and international arms control and nonproliferation. Two plenary lectures began each morning and each afternoon session and highlighted the breakout sessions on coordination/organometallic chemistry, solid-state physics, environmental chemistry, materials science, separations and reprocessing, advanced fuels and waste forms, phase transformations, solution …
Date: July 12, 2007
Creator: Fluss, M; Hobart, D; Allan, P & Jarvinen, G
System: The UNT Digital Library
Design of an Interaction Region with Head-On Collisions for the ILC (open access)

Design of an Interaction Region with Head-On Collisions for the ILC

An interaction region (IR) with head-on collisions is considered as an alternative to the baseline configuration of the International Linear Collider (ILC) which includes two IRs with finite crossing-angles (2 and 20 mrad). Although more challenging for the beam extraction, the head-on scheme is favored by the experiments because it allows a more convenient detector configuration, particularly in the forward region. The optics of the head-on extraction is revisited by separating the e+ and e- beams horizontally, first by electrostatic separators operated at their LEP nominal field and then using a defocusing quadrupole of the final focus beam line. In this way the septum magnet is protected from the beamstrahlung power. Newly optimized final focus and extraction optics are presented, including a first look at post-collision diagnostics. The influence of parasitic collisions is shown to lead to a region of stable collision parameters. Disrupted beam and beamstrahlung photon losses are calculated along the extraction elements.
Date: July 12, 2006
Creator: Appleby, R.; U., /Cockcroft Inst. Accel. Sci. Tech. /Manchester; Angal-Kalinin, D.; Jackson, F.; /Daresbury; Alabau-Pons, M . et al.
System: The UNT Digital Library
Hollow Waveguide Gas Sensor for Mid-Infrared Trace Gas Analysis (open access)

Hollow Waveguide Gas Sensor for Mid-Infrared Trace Gas Analysis

A hollow waveguide mid-infrared gas sensor operating from 1000 cm{sup -1} to 4000 cm{sup -1} has been developed, optimized, and its performance characterized by combining a FT-IR spectrometer with Ag/Ag-halide hollow core optical fibers. The hollow core waveguide simultaneously serves as a light guide and miniature gas cell. CH{sub 4} was used as test analyte during exponential dilution experiments for accurate determination of the achievable limit of detection (LOD). It is shown that the optimized integration of an optical gas sensor module with FT-IR spectroscopy provides trace sensitivity at the few hundreds of parts-per-billion concentration range (ppb, v/v) for CH{sub 4}.
Date: July 12, 2007
Creator: Kim, S.; Young, C.; Chan, J.; Carter, C. & Mizaikoff, B.
System: The UNT Digital Library
Use of Imperfect Calibration for Seismic Location (open access)

Use of Imperfect Calibration for Seismic Location

Efforts to more effectively monitor nuclear explosions include the calibration of travel times along specific paths. Benchmark events are used to improve travel-time prediction by (1) improving models, (2) determining travel times empirically, or (3) using a hybrid approach. Even velocity models that are determined using geophysical analogy (i.e. models determined without the direct use of calibration data) require validation with calibration events. Ideally, the locations and origin times of calibration events would be perfectly known. However, the existing set of perfectly known events is spatially limited and many of these events occurred prior to the installation of current monitoring stations, thus limiting their usefulness. There are, however, large numbers of well (but not perfectly) located events that are spatially distributed, and many of these events may be used for calibration. Identifying the utility and limitations of the spatially distributed set of imperfect calibration data is of paramount importance to the calibration effort. In order to develop guidelines for calibration utility, we examine the uncertainty and correlation of location parameters under several network configurations that are commonly used to produce calibration-grade locations. We then map these calibration uncertainties through location procedures with network configurations that are likely in monitoring situations. …
Date: July 12, 2000
Creator: Myers, S C & Schultz, C A
System: The UNT Digital Library
The MC&A Council at SSC RF-IPPE as a Coordinating Body for System Sustainability (open access)

The MC&A Council at SSC RF-IPPE as a Coordinating Body for System Sustainability

The State Scientific Center of the Russian Federation - Institute of Physics and Power Engineering's (SSC RF - IPPE) practice of nuclear material control and accounting (MC&A) has undergone significant changes during the period of cooperation with U.S. national laboratories from 1995 to the present. These changes corresponded with general changes of the Russian system of state control and accounting of nuclear materials resulting from the new Concept of the System for State Regulating and Control of Nuclear Materials (1996) and further regulatory documents, which were developed and implemented to take into account international experience in the MC&A [1]. During the upgrades phase of Russian-U.S. cooperation, an MC&A laboratory was specially created within the SSC RF - IPPE for the purpose of guiding the creation of the upgraded MC&A system, coordinating the activities of all units involved in the creation of this system, and implementing a unified technical policy during the transition period. After five years of operation of the MC&A laboratory and the implementation of new components for the upgraded MC&A system, it was decided that a greater degree of attention must be paid to the MC&A system's operation in addition to the coordination activities carried out by the …
Date: July 12, 2004
Creator: Poplavko, V.; Skorkin, V. & Myakishev, G.
System: The UNT Digital Library
Explosion in the Granite Field: Hardening and Softening Behavior in Rocks (open access)

Explosion in the Granite Field: Hardening and Softening Behavior in Rocks

Properties of rock materials under quasistatic conditions are well characterized in laboratory experiments. Unfortunately, quasistatic data alone are not sufficient to calibrate models for use to describe inelastic wave propagation associated with conventional and nuclear explosions, or with impact. First, rock properties are size-dependent. properties measured using laboratory samples on the order of a few centimeters in size need to be modified to adequately describe wave propagation in a problem on the order of a few hundred meters in size. Second, there is lack of data about the damage (softening) behavior of rock because most laboratory tests focus on the pre-peak hardening region with very little emphasis on the post-peak softening region. This paper presents a model for granite that accounts for both the hardening and softening of geologic materials, and also provides a simple description of rubblized rock. The model is shown to reproduce results of quasistatic triaxial experiments as well as peak velocity and peak displacement attenuation from a compendium of dynamic wave propagation experiments that includes US and French nuclear tests in granite.
Date: July 12, 2001
Creator: Lomov, I N; Antoun, T H & Glenn, L A
System: The UNT Digital Library
Thermal Expansion of AuIn2 (open access)

Thermal Expansion of AuIn2

The thermal expansion of AuIn{sub 2} gold is of great interest in soldering technology. Indium containing solders have been used to make gold wire interconnects at low soldering temperature and over time, AuIn{sub 2} is formed between the gold wire and the solder due to the high heat of formation and the high inter-metallic diffusion of indium. Hence, the thermal expansion of AuIn{sub 2} alloy in comparison with that of the gold wire and the indium-containing solder is critical in determining the integrity of the connection. We present the results of x-ray diffraction measurement of the coefficient of linear expansion of AuIn{sub 2} as well as the bulk expansion and density changes over the temperature range of 30 to 500 C.
Date: July 12, 2004
Creator: Saw, C K & Siekhaus, W J
System: The UNT Digital Library
The role of Hydrogen and Creep in Intergranular Stress Corrosion Cracking of Alloy 600 and Alloy 690 in PWR Primary Water Environments ? a Review (open access)

The role of Hydrogen and Creep in Intergranular Stress Corrosion Cracking of Alloy 600 and Alloy 690 in PWR Primary Water Environments ? a Review

Intergranular attack (IGA) and intergranular stress corrosion cracking (IGSCC) of Alloy 600 in PWR steam generator environment has been extensively studied for over 30 years without rendering a clear understanding of the essential mechanisms. The lack of understanding of the IGSCC mechanism is due to a complex interaction of numerous variables such as microstructure, thermomechanical processing, strain rate, water chemistry and electrochemical potential. Hydrogen plays an important role in all these variables. The complexity, however, significantly hinders a clearer and more fundamental understanding of the mechanism of hydrogen in enhancing intergranular cracking via whatever mechanism. In this work, an attempt is made to review the role of hydrogen based on the current understanding of grain boundary structure and chemistry and intergranular fracture of nickel alloys, effect of hydrogen on electrochemical behavior of Alloy 600 and Alloy 690 (e.g. the passive film stability, polarization behavior and open-circuit potential) and effect of hydrogen on PWSCC behavior of Alloy 600 and Alloy 690. Mechanistic studies on the PWSCC are briefly reviewed. It is concluded that further studies on the role of hydrogen on intergranular cracking in both inert and primary side environments are needed. These studies should focus on the correlation of the …
Date: July 12, 2004
Creator: Rebak, R B & Hua, F H
System: The UNT Digital Library
Non-Proliferative, Thorium-Based, Core and Fuel Cycle for Pressurized Water Reactors (open access)

Non-Proliferative, Thorium-Based, Core and Fuel Cycle for Pressurized Water Reactors

Two of the major barriers to the expansion of worldwide adoption of nuclear power are related to proliferation potential of the nuclear fuel cycle and issues associated with the final disposal of spent fuel. The Radkowsky Thorium Fuel (RTF) concept proposed by Professor A. Radkowsky offers a partial solution to these problems. The main idea of the concept is the utilization of the seed-blanket unit (SBU) fuel assembly geometry which is a direct replacement for a 'conventional' assembly in either a Russian pressurized water reactor (VVER-1000) or a Western pressurized water reactor (PWR). The seed-blanket fuel assembly consists of a fissile (U) zone, known as seed, and a fertile (Th) zone known as blanket. The separation of fissile and fertile allows separate fuel management schemes for the thorium part of the fuel (a subcritical 'blanket') and the 'driving' part of the core (a supercritical 'seed'). The design objective for the blanket is an efficient generation and in-situ fissioning of the U233 isotope, while the design objective for the seed is to supply neutrons to the blanket in a most economic way, i.e. with minimal investment of natural uranium. The introduction of thorium as a fertile component in the nuclear fuel …
Date: July 12, 2009
Creator: M., Todosow; M., Todosow & Raitses, G. (BNL) Galperin, A. (Ben Gurion University)
System: The UNT Digital Library
Next Generation Safeguards Initiative Workshop on Enhanced Recruiting for International Safeguards (open access)

Next Generation Safeguards Initiative Workshop on Enhanced Recruiting for International Safeguards

Brookhaven National Laboratory (BNL) hosted a Workshop on Enhanced Recruiting for International Safeguards October 22 and 23, 2008. The workshop was sponsored by DOE/NA-243 under the Next Generation Safeguards Initiative (NGSI). Placing well-qualified Americans in sufficient number and in key safeguards positions within the International Atomic Energy Agency’s (IAEA’s) Department of Safeguards is an important U.S. non-proliferation objective. The goal of the NGSI Workshop on Enhanced Recruiting for International Safeguards was to improve U.S. efforts to recruit U.S. citizens for IAEA positions in the Department of Safeguards. The participants considered the specific challenges of recruiting professional staff, safeguards inspectors, and managers. BNL’s International Safeguards Project Office invited participants from the U.S. Department of Energy, the IAEA, U.S. national laboratories, private industry, academia, and professional societies who are either experts in international safeguards or who understand the challenges of recruiting for technical positions. A final report for the workshop will be finalized and distributed in early 2009. The main finding of the workshop was the need for an integrated recruitment plan to take into account pools of potential candidates, various government and private agency stakeholders, the needs of the IAEA, and the NGSI human capital development plan. There were numerous findings …
Date: July 12, 2009
Creator: Pepper, S. E.; Rosenthal, M. D.; Fishbone, L. G.; Occhogrosso, D. M.; Lockwood, D.; Carroll, C. J. et al.
System: The UNT Digital Library
Nanosecond Mid-Infrared Detection for Pulse Radiolysis (open access)

Nanosecond Mid-Infrared Detection for Pulse Radiolysis

Pulse radiolysis, utilizing electron pulses from accelerators, is the definitive method for adding single positive or negative charges to molecules. It is also among the most effective means for creating free radicals. Such species are particularly important in applications such as redox catalysis relevant to solar energy conversion and advanced nuclear energy systems. Coupled with fast UV-visible detection, pulse radiolysis has become an extremely powerful method for monitoring the kinetics of the subsequent reactions of these species on timescales ranging from picoseconds to seconds. However, in many important contexts the radicals formed are difficult to identify due to their broad and featureless UV-visible absorption spectra. Time-resolved infrared (TRIR) absorption spectroscopy is a powerful structural probe of short-lived intermediates, which allows multiple transient species to be clearly identified and simultaneously monitored in a single process. Unfortunately, due to technical challenges the coupling of fast (sub-millisecond) TRIR with pulse radiolysis has received little attention, being confined to gas-phase studies. Taking advantage of recent developments in mid-IR laser technology, we have recently begun developing nanosecond TRIR detection methodologies for condensed-phase samples at our Laser Electron Accelerator Facility (LEAF). The results of preliminary pulse radiolysis-TRIR investigations on the formation of the one-electron reduced forms …
Date: July 12, 2009
Creator: Grills, D. C.; Preses, J. M.; Wishart, J. F. & Cook, A. R.
System: The UNT Digital Library
Proliferation Risk Reduction Study of Alternative Spent Fuel Processing (open access)

Proliferation Risk Reduction Study of Alternative Spent Fuel Processing

This paper presents the results of an evaluation of the relative proliferation risks of particular reprocessing technologies focusing on COEX, UREX+, and pyroprocessing
Date: July 12, 2009
Creator: Bari, R. A.; Phillips, J.; Pilat, J.; Rochau, G.; Therios, I.; Wigeland, R. et al.
System: The UNT Digital Library
In-Born Radio Frequency Identification Devices for Safeguards Use at Gas-Centrifuge Enrichment Plants (open access)

In-Born Radio Frequency Identification Devices for Safeguards Use at Gas-Centrifuge Enrichment Plants

Global expansion of nuclear power has made the need for improved safeguards measures at Gas Centrifuge Enrichment Plants (GCEPs) imperative. One technology under consideration for safeguards applications is Radio Frequency Identification Devices (RFIDs). RFIDs have the potential to increase IAEA inspector"s efficiency and effectiveness either by reducing the number of inspection visits necessary or by reducing inspection effort at those visits. This study assesses the use of RFIDs as an integral component of the "Option 4" safeguards approach developed by Bruce Moran, U.S. Nuclear Regulatory Commission (NRC), for a model GCEP [1]. A previous analysis of RFIDs was conducted by Jae Jo, Brookhaven National Laboratory (BNL), which evaluated the effectiveness of an RFID tag applied by the facility operator [2]. This paper presents a similar evaluation carried out in the framework of Jo’s paper, but it is predicated on the assumption that the RFID tag is applied by the manufacturer at the birth of the cylinder, rather than by the operator. Relevant diversion scenarios are examined to determine if RFIDs increase the effectiveness and/ or efficiency of safeguards in these scenarios. Conclusions on the benefits offered to inspectors by using in-born RFID tagging are presented.
Date: July 12, 2009
Creator: Ward, R. & Rosenthal, M.
System: The UNT Digital Library
Development, Installation and Operation of the Mpc&a Operations Monitoring (Mom) System at the Joint Institute for Nuclear Research (Jinr) Dubna, Russia (open access)

Development, Installation and Operation of the Mpc&a Operations Monitoring (Mom) System at the Joint Institute for Nuclear Research (Jinr) Dubna, Russia

The Material Protection, Control and Accounting (MPC&A) Operations Monitoring (MOM) systems handling at the International Intergovernmental Organization - Joint Institute for Nuclear Research (JINR) is described in this paper. Category I nuclear material (plutonium and uranium) is used in JINR research reactors, facilities and for scientific and research activities. A monitoring system (MOM) was installed at JINR in April 2003. The system design was based on a vulnerability analysis, which took into account the specifics of the Institute. The design and installation of the MOM system was a collaborative effort between JINR, Brookhaven National Laboratory (BNL) and the U.S. Department of Energy (DOE). Financial support was provided by DOE through BNL. The installed MOM system provides facility management with additional assurance that operations involving nuclear material (NM) are correctly followed by the facility personnel. The MOM system also provides additional confidence that the MPC&A systems continue to perform effectively.
Date: July 12, 2009
Creator: Kartashov, V. V.; Pratt, W.; Romanov, Y. A.; Samoilov, V. N.; Shestakov, B. A.; Duncan, C. et al.
System: The UNT Digital Library
Solid-Solid Phase Transition Kinetics of FOX-7 (open access)

Solid-Solid Phase Transition Kinetics of FOX-7

Since it was developed in the late 1990s, 1,1-diamino-2,2-dinitroethene (FOX-7), with lower sensitivity and comparable performance to RDX, has received increasing interest. This paper will present our results for the phase changes of FOX-7 using DSC and HFC (Heat Flow Calorimetry). DSC thermal curves recorded at linear heating rates of 0.10, 0.35 and 1.0 C min{sup -1} show two endothermic peaks and two exothermic peaks. The two endothermic peaks represent solid-solid phase transitions, which have been observed in the literature at 114 C ({beta}-{gamma}) and 159 C ({gamma}-{delta}) by both DSC and XPD (X-ray powder diffraction) measurements. The first transition shifts from 114.5 to 115.8 C as the heating rate increases from 0.10 to 1.0 C min{sup -1}, while the second transition shifts from 158.5 to 160.4 C. Cyclical heating experiments show the endotherms and exotherms for a first heating through the {gamma} phase to the {delta} phase, a cooling and reversion to the {alpha} or {beta} phase, and a second heating to the {gamma} and {delta} phases. The data are interpreted using kinetic models with thermodynamic constraints.
Date: July 12, 2005
Creator: Burnham, A K; Weese, R K; Wang, R; Kwok, Q M & Jones, D G
System: The UNT Digital Library
Air convection noise of pencil-beam interferometer for long traceprofiler (open access)

Air convection noise of pencil-beam interferometer for long traceprofiler

In this work, we investigate the effect of air convection onlaser-beam pointing noise essential for the long trace profiler (LTP). Wedescribe this pointing error with noise power density (NPD) frequencydistributions. It is shown that the NPD spectra due to air convectionhave a very characteristic form. In the range of frequencies from ~;0.05Hz to ~;0.5 Hz, the spectra can be modeled with an inverse-power-lawfunction. Depending on the intensity of air convection that is controlledwith a resistive heater of 100 to 150 mW along a one-meter-long opticalpath, the power index lies between 2 and 3 at an overall rms noise of~;0.5 to 1 microradian. The efficiency of suppression of the convectionnoise by blowing air across the beam optical path is also discussed.Air-blowing leads to a white-noise-like spectrum. Air blowing was appliedto the reference channel of an LTP allowing demonstration of thecontribution of air convection noise to the LTP reference beam. Theability to change (with the blowing technique presented) the spectralcharacteristics of the beam pointing noise due to air convection allowsone to investigate the contribution of the convection effect, and thusmake corrections to the power spectral density spectra measured with theLTP.
Date: July 12, 2006
Creator: Yashchuk, Valeriy V.; Irick, Steve C.; MacDowell, Alastair A.; McKinney, Wayne R. & Takacs, Peter Z.
System: The UNT Digital Library
Spectroscopic Observations and Analysis of the Unusual Type Ia SN1999ac (open access)

Spectroscopic Observations and Analysis of the Unusual Type Ia SN1999ac

The authors present optical spectra of the peculiar Type Ia supernova (SN Ia) 1999ac. The data extend from -15 to +42 days with respect to B-band maximum and reveal an event that is unusual in several respects. prior to B-band maximum, the spectra resemble those of SN 1999aa, a slowly declining event, but possess stronger Si II and Ca II signatures (more characteristic of a spectroscopically normal SN). Spectra after B-band maximum appear more normal. The expansion velocities inferred from the Iron lines appear to be lower than average; whereas, the expansion velocity inferred from Calcium H and K are higher than average. The expansion velocities inferred from the Iron lines appear to be lower than average; whereas, the expansion velocity inferred from Calcium H and K are higher than average. The expansion velocities inferred from Si II are among the slowest ever observed, though SN 1999ac is not particularly dim. The analysis of the parameters v{sub 10}(Si II), R(Si II), v, and {Delta}m{sub 15} further underlines the unique characteristics of SN 1999ac. They find convincing evidence of C II {lambda}6580 in the day -15 spectrum with ejection velocity v > 16,000 km s{sup -1}, but this signature disappears by …
Date: July 12, 2005
Creator: Garavini, G.; Aldering, G.; Amadon, A.; Amanullah, R.; Astier, P.; Balland, C. et al.
System: The UNT Digital Library
Simulation of the ILC Collimation System using BDSIM, MARS15 and STRUCT (open access)

Simulation of the ILC Collimation System using BDSIM, MARS15 and STRUCT

None
Date: July 12, 2006
Creator: Carter, J.; Agapov, I.; Blair, G. A.; Deacon, L.; Drozhdin, A. I.; Mokhov, N. V. et al.
System: The UNT Digital Library
THERMAL AND SPECTROSCOPIC ANALYSES OF CAUSTIC LIDE SOLVENT EXTRACTION SOLVENT CONTACTED WITH 16 MOLAR AND 8 MOLAR NITRIC ACID (open access)

THERMAL AND SPECTROSCOPIC ANALYSES OF CAUSTIC LIDE SOLVENT EXTRACTION SOLVENT CONTACTED WITH 16 MOLAR AND 8 MOLAR NITRIC ACID

Thermal and spectroscopic analyses were performed on multiple layers formed from contacting Caustic Side Solvent Extraction (CSSX) solvent with 1 M or 3 M nitric acid. A slow chemical reaction occurs (i.e., over several weeks) between the solvent and 1 M or 3 M nitric acid as evidenced by color changes and the detection of nitro groups in the infrared spectrum of the aged samples. Thermal analysis revealed that decomposition of the resulting mixture does not meet the definition of explosive or deflagrating material.
Date: July 12, 2007
Creator: Fondeur, F; David Hobbs, D & Samuel Fink, S
System: The UNT Digital Library
Temporal Characterization of Femtosecond Laser-Plasma-AcceleratedElectron Bunches using THz Radiation (open access)

Temporal Characterization of Femtosecond Laser-Plasma-AcceleratedElectron Bunches using THz Radiation

The temporal pro le of relativistic laser-plasma-acceleratedelectron bunches has been characterized. Coherent transition radiation atTHz frequencies, emitted at the plasma-vacuum boundary, is measuredthrough electro-optic sampling. The data indicates that THz radiation isemitted by a skewed bunch with a sub-50 fs rise time and a ~; 600 fs tail(half-width-at-half-maximum), consistent with ballistic debunching of 100percent-energy-spread beams. The measurement demonstrates bothshot-to-shot stability of the laser-plasma accelerator and femtosecondsynchronization between bunch and probe beam.
Date: July 12, 2005
Creator: van Tilborg, J.; Schroeder, C. B.; Filip, C. V.; Toth, Cs.; Geddes, C. G. R.; Fubiani, G. et al.
System: The UNT Digital Library
Simulation of the ILC Collimation System using BDSIM, MARS15 and STRUCT (open access)

Simulation of the ILC Collimation System using BDSIM, MARS15 and STRUCT

The simulation codes BDSIM, MARS15 and STRUCT are used to simulate in detail the collimation section of the International Linear Collider (ILC). A comparative study of the collimation system performance for the 250 x 250 GeV machine is conducted, and the key radiation loads are calculated. Results for the latest ILC designs are presented together with their implications for future design iterations.
Date: July 12, 2006
Creator: Carter, J.; Agapov, I.; Blair, G. A.; Deacon, L.; Drozhdin, A.I.; Mokhov, N. V. et al.
System: The UNT Digital Library