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Extended Community: An Oral History of the Community Environmental Monitoring Program (CEMP), 1989 - 2003

Description: Studying the Community Environmental Monitoring Program (CEMP) provides a unique opportunity to trace a concept created by two nuclear industry originators from inception, as it transitioned through several stewardship agencies, to management by a non-profit organization. This transition is informed not only by changes over two decades in the views of the general populace toward nuclear testing but also by changing political climates and public policies. Several parallel histories accompanied the development of the CEMP: an administrative history, an environmental history, and a history of changing public perception of not only nuclear testing, but other activities involving radiation such as waste transportation, as well. Although vital, those histories will be provided only as background to the subject of this study, the oral histories gathered in this project. The oral histories collected open a window into the nuclear testing history of Nevada and Utah that has not heretofore been opened. The nuclear industry has generated a great deal of positive and negative reaction since its inception. The CEMP emerged with specific objectives. It was designed to provide information to potential downwind communities and counter negative perceptions by creating more community involvement and education about the testing. The current objectives of the program are to: (1) Manage and maintain the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) offsite monitoring program including 26 radiation and environmental monitoring stations with associated equipment. Provide air sample collection and analysis, radiological and meteorological data collection, interpretation and reporting. (2) Facilitate independent operation of radiological monitoring stations and data verification by private citizens living in communities in proximity to the Nevada Test Site (NTS). (3) Hire and initiate training of local citizens to serve as Community Environmental Monitors (CEMs) in designated communities. (4) Provide relevant training by qualified instructors to the CEMs ...
Date: July 1, 2004
Creator: DeSilva, Susan
Partner: UNT Libraries Government Documents Department

A Simple Model for Induction Core Voltage Distributions

Description: In fall 2003 T. Hughes of MRC used a full EM simulation code (LSP) to show that the electric field stress distribution near the outer radius of the longitudinal gaps between the four Metglas induction cores is very nonuniform in the original design of the DARHT-2 accelerator cells. In this note we derive a simple model of the electric field distribution in the induction core region to provide physical insights into this result. The starting point in formulating our model is to recognize that the electromagnetic fields in the induction core region of the DARHT-2 accelerator cells should be accurately represented within a quasi-static approximation because the timescale for the fields to change is much longer than the EM wave propagation time. The difficulty one faces is the fact that the electric field is a mixture of both a ''quasi-magnetostatic field'' (having a nonzero curl, with Bdot the source) and a ''quasi-electrostatic field'' (the source being electric charges on the various metal surfaces). We first discuss the EM field structure on the ''micro-scale'' of individual tape windings in Section 2. The insights from that discussion are then used to formulate a ''macroscopic'' description of the fields inside an ''equivalent homogeneous tape wound core region'' in Section 3. This formulation explicitly separates the nonlinear core magnetics from the quasi-electrostatic components of the electric field. In Section 4 a physical interpretation of the radial dependence of the electrostatic component of the electric field derived from this model is presented in terms of distributed capacitances, and the voltage distribution from gap to gap is related to various ''equivalent'' lumped capacitances. Analytic solutions of several simple multi-core cases are presented in Sections 5 and 6 to help provide physical insight into the effect of various proposed changes in the geometrical parameters of the DARHT-2 ...
Date: July 1, 2004
Creator: Briggs, Richard J. & Fawley, William M.
Partner: UNT Libraries Government Documents Department

Measurement of Radon, Thoron, Isotopic Uranium and Thorium to Determine Occupational and Environmental Exposure and Risk at Fernald Feed Material Production Center

Description: To develop a new and novel area and personal radon/thoron detector for both radon isotopes to better measure the exposure to low airborne concentrations of these gases at Fernald. These measurements are to be used to determine atmospheric dispersion and exposure to radon and thoron prior to and during retrieval and removal of the 4000 Ci of radium in the two silos at Fernald.
Date: July 1, 2004
Creator: Naomi H. Harley, Ph.D.
Partner: UNT Libraries Government Documents Department

Tunable coherent radiation at soft X-ray wavelengths: Generation and interferometric applications

Description: The availability of high power, spectrally and spatially coherent soft x-rays (SXR) would facilitate a wide variety of experiments as this energy region covers the primary resonances of many magnetic and biological materials. Specifically, there are the carbon and oxygen K-edges that are critical for biological imaging in the water window and the L-edges of iron, nickel, and cobalt for which imaging and scattering studies can be performed. A new coherent soft X-ray branchline at the Advanced Light Source has begun operation (beamline 12.0.2). Using the third harmonic from an 8 cm period undulator, this branch delivers coherent soft x-rays with photon energies ranging from 200eV to 1keV. This branchline is composed of two sub-branches one at 14X demagnification and the other 8X demagnification. The former is optimized for use at 500eV and the latter at 800eV. Here the expected power from the third harmonic of this undulator and the beamline design and characterization is presented. The characterization includes measurements on available photon flux as well as a series of double pinhole experiments to determine the coherence factor with respect to transverse distance. The first high quality Airy patterns at SXR wavelengths are created with this new beamline. The operation of this new beamline allows for interferometry to be performed in the SXR region. Here an interferometric experiment designed to directly determine the index of refraction of a material under test is performed. Measurements are first made in the EUV region using an established beamline (beamline12.0.1) to measure silicon, ruthenium and tantalum silicon nitride. This work is then extended to the SXR region using beamline 12.0.2 to test chromium and vanadium.
Date: July 1, 2004
Creator: Rosfjord, Kristine Marie
Partner: UNT Libraries Government Documents Department

Nanoparticle production by UV irradiation of combustion generated soot particles

Description: Laser ablation of surfaces normally produce high temperature plasmas that are difficult to control. By irradiating small particles in the gas phase, we can better control the size and concentration of the resulting particles when different materials are photofragmented. Here, we irradiate soot with 193 nm light from an ArF excimer laser. Irradiating the original agglomerated particles at fluences ranging from 0.07 to 0.26 J/cm{sup 2} with repetition rates of 20 and 100 Hz produces a large number of small, unagglomerated particles, and a smaller number of spherical agglomerated particles. Mean particle diameters from 20 to 50 nm are produced from soot originally having a mean electric mobility diameter of 265nm. We use a non-dimensional parameter, called the photon/atom ratio (PAR), to aid in understanding the photofragmentation process. This parameter is the ratio of the number of photons striking the soot particles to the number of the carbon atoms contained in the soot particles, and is a better metric than the laser fluence for analyzing laser-particle interactions. These results suggest that UV photofragmentation can be effective in controlling particle size and morphology, and can be a useful diagnostic for studying elements of the laser ablation process.
Date: July 1, 2004
Creator: Stipe, Christopher B.; Choi, Jong Hyun; Lucas, Donald; Koshland, Catherine P. & Sawyer, Robert F.
Partner: UNT Libraries Government Documents Department

Customer response to day-ahead wholesale market electricity prices: Case study of RTP program experience in New York

Description: There is growing interest in policies, programs and tariffs that encourage customer loads to provide demand response (DR) to help discipline wholesale electricity markets. Proposals at the retail level range from eliminating fixed rate tariffs as the default service for some or all customer groups to reinstituting utility-sponsored load management programs with market-based inducements to curtail. Alternative rate designs include time-of-use (TOU), day-ahead real-time pricing (RTP), critical peak pricing, and even pricing usage at real-time market balancing prices. Some Independent System Operators (ISOs) have implemented their own DR programs whereby load curtailment capabilities are treated as a system resource and are paid an equivalent value. The resulting load reductions from these tariffs and programs provide a variety of benefits, including limiting the ability of suppliers to increase spot and long-term market-clearing prices above competitive levels (Neenan et al., 2002; Boren stein, 2002; Ruff, 2002). Unfortunately, there is little information in the public domain to characterize and quantify how customers actually respond to these alternative dynamic pricing schemes. A few empirical studies of large customer RTP response have shown modest results for most customers, with a few very price-responsive customers providing most of the aggregate response (Herriges et al., 1993; Schwarz et al., 2002). However, these studies examined response to voluntary, two-part RTP programs implemented by utilities in states without retail competition.1 Furthermore, the researchers had limited information on customer characteristics so they were unable to identify the drivers to price response. In the absence of a compelling characterization of why customers join RTP programs and how they respond to prices, many initiatives to modernize retail electricity rates seem to be stymied.
Date: July 1, 2004
Creator: Goldman, C.; Hopper, N.; Sezgen, O.; Moezzi, M.; Bharvirkar, R.; Neenan, B. et al.
Partner: UNT Libraries Government Documents Department

Correction and alignment strategies for the beam separator of thePEEM3 microscope

Description: A new high-resolution aberration corrected photoemission electron microscope (PEEM3) will be installed on an undulator beam line at the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory. The aim of this instrument is to provide a substantial flux and resolution improvement by employing an electron mirror for correcting both the third-order spherical aberration and the primary chromatic aberration. In order to utilize this concept of correction, a beam separator is a prerequisite. Crucial to achieving a resolution of 5nm for the high resolution mode, and a sixteen-fold increase in throughput at the same resolution as its predecessor, PEEM2, specified as 20nm at 2% transmission, for the high flux mode is the double symmetric design of the beam separator, which eliminates all the second order geometric aberrations. Nonetheless, substantial tuning capabilities must be incorporated into the PEEM3 design to compensate for both systematic and random errors. In this paper, we investigate how to correct for non-systematic imperfections and for systematic uncertainties in the accuracy of the magnetic fields and focus on how degradation of the resolution and the field of view can be minimized. Finally, we outline a tentative correction strategy for PEEM3.
Date: July 1, 2004
Creator: Schmid, Peter; Feng, Jun; Padmore, Howard; Robin, David; Rose,Harald; Schlueter, Ross et al.
Partner: UNT Libraries Government Documents Department

Monitoring the Energy-Use Effects of Cool Roofs on California Commercial Buildings

Description: Solar-reflective roofs stay cooler in the sun than solar-absorptive roofs. Such ''cool'' roofs achieve lower surface temperatures that reduce heat conduction into the building and the building's cooling load. The California Energy Commission has funded research in which Lawrence Berkeley National Laboratory (LBNL) has measured the electricity use and peak demand in commercial buildings to document savings from implementing the Commission's Cool Roofs program. The study seeks to determine the savings achieved by cool roofs by monitoring the energy use of a carefully selected assortment of buildings participating in the Cool Roofs program. Measurements were needed because the peak savings resulting from the application of cool roofs on different types of buildings in the diverse California climate zones have not been well characterized to date. Only a few occupancy categories (e.g., office and retail buildings) have been monitored before this, and those were done under a limited number of climatic conditions. To help rectify this situation, LBNL was tasked to select the buildings to be monitored, measure roof performance before and after replacing a hot roof by a cool roof, and document both energy and peak demand savings resulting from installation of cool roofs. We monitored the effects of cool roofs on energy use and environmental parameters in six California buildings at three different sites: a retail store in Sacramento; an elementary school in San Marcos (near San Diego); and a 4-building cold storage facility in Reedley (near Fresno). The latter included a cold storage building, a conditioning and fruit-palletizing area, a conditioned packing area, and two unconditioned packing areas (counted as one building).
Date: July 1, 2004
Creator: Akbari, Hashem; Levinson, Ronnen; Konopaki, Steve & Rainer, Leo
Partner: UNT Libraries Government Documents Department

A laser-based longitudinal density monitor for the large hadroncollider

Description: We report on the development of an instrument for the measurement of the longitudinal beam profile in the Large Hadron Collider (LHC). The technique used, which has been successfully demonstrated at the Advanced Light Source, mixes the synchrotron radiation with the light from a mode-locked solid state laser oscillator in a non-linear crystal.The up-converted radiation is then detected with a photomultiplier and processed to extract, store and display the required information. A 40MHz laser, phase-locked to the ring radio frequency system, with a 50 pspulse length, would be suitable for measuring the dynamics of the core of each of the LHC 2808 bunches in a time span much shorter than the synchrotron period. The same instrument could also monitor the evolution of the bunch tails, the presence of untrapped particles and their diffusion into nominally empty RF buckets (''ghost bunches'') as required by the CERN specifications.
Date: July 1, 2004
Creator: Beche, J.-F.; Byrd, J.; Datte, P.; De Santis, S.; Placidi, M.; Riot, V. et al.
Partner: UNT Libraries Government Documents Department

Tailoring Inorganic Sorbents for SRS Strontium and Actinide Separations: Optimized Monosodium Titanate and Pharmacosiderite Phase I Final Report

Description: This report summarizes experiments and engineering evaluations conducted in a project funded by the Department of Energy, Office of Environmental Cleanup and Acceleration to develop improved sorbent materials for strontium/actinide separations at SRS. From the results of Phase 1 activities of the project, we offer the following conclusions and recommendations. Chemically modified monosodium titanate (MST) samples exhibited significantly increased actinide removal performance compared to the baseline MST. Testing results indicate that the modified MST offers the possibility of reduced MST concentrations and shorter contact times compared to the baseline MST. Preliminary calculations indicate that the use of the optimized MST sorbent will provide significantly increased waste throughput in the ARP facilities should shorter batch contact times and reduced MST concentrations be realized. The maximum throughput increases are realized using a 0.1-micron pore-size filter media in these facilities. Evaluation of the impacts of incorporating MST into DWPF operations indicates that both the baseline MST and optimized MST (4X decrease) quantities can be accommodated from Chemical Processing Cell (CPC) and glass formulation perspectives. We recommend that the MST materials be tested to determine the effects, if any, that introduction of MST has on slurry rheology, antifoam effectiveness, potential generation of hydrogen and processing time in the CPC. Evaluation of the impacts of MST and titanosilicate analog of pharmacosiderite (TSP) materials determined that the use of these materials showed no significant impacts on the SWPF and Saltstone facility. Based on the promising enhanced actinide removal performance of the chemically modified MST samples, which could have significant positive impacts on the SWPF, ARP and perhaps an in-tank deployment for Sr/actinide removal, we recommend that the Department of Energy continue funding to develop chemically modified MST materials. Dried MST exhibited poorer strontium and alpha removal kinetics, which may adversely impact process cycle times and waste ...
Date: July 1, 2004
Creator: HOBBS, DAVID
Partner: UNT Libraries Government Documents Department

Sub-Angstrom metrology of resolution in aberration-corrected transmission electron microscopes using the A-OK standard test specimens

Description: Using specimens with diamond cubic and zincblende structures, oriented to provide pairs of atoms in ''dumbbell'' configurations, we have identified specimens with well-characterized atom separations over a 3:1 range of spacings straddling the canonical 1 Angstrom value. Spacings ranging from 1.6 Angstrom to 0.5 Angstrom are available from an ''A-OK'' set of test specimens carefully selected for their stability and well-characterized lattice parameters.
Date: July 1, 2004
Creator: Allard, Lawrence F. & O'Keefe, Michael A.
Partner: UNT Libraries Government Documents Department

The potential impacts of a competitive wholesale market in the midwest: A preliminary examination of centralized dispatch

Description: In March 2005, the Midwest Independent System Operator (MISO) will begin operating the first-ever wholesale market for electricity in the central and upper Midwestern portion of the United States. Region-wide, centralized, security-constrained, bid-based dispatch will replace the current system of decentralized dispatch by individual utilities and control areas. This report focuses on how the operation of generators may change under centralized dispatch. We analyze a stylized example of these changes by comparing a base case dispatch based on a ''snapshot'' taken from MISO's state estimator for an actual, historical dispatch (4 p.m., July 7, 2003) to a hypothetical, centralized dispatch that seeks to minimize the total system cost of production, using estimated cost data collected by the EIA. Based on these changes in dispatch, we calculate locational marginal prices, which in turn reveals the location of congestion within MISO's footprint, as well as the distribution of congestion revenues. We also consider two sensitivity scenarios that examine (1) the effect of changes in MISO membership (2003 vs. 2004 membership lists), and (2) different load and electrical data, based on a snapshot from a different date and time (1 p.m., Feb. 18, 2004). Although our analysis offers important insights into how the MISO market could operate when it opens, we do not address the question of the total benefits or costs of creating a wholesale market in the Midwest.
Date: July 1, 2004
Creator: Lesieutre, Bernard C.; Bartholomew, Emily; Eto, Joseph H.; Hale, Douglas & Luong, Thanh
Partner: UNT Libraries Government Documents Department

Development of an abort gap monitor for the large hadroncollider

Description: The Large Hadron Collider (LHC), presently under construction at CERN, requires monitoring the parasitic charge in the 3.3ms long gap in the machine fill structure. This gap, referred to as the abort gap, corresponds to the raise time of the abort kickers magnets. Any circulating particle present in the abort gap at the time of the kickers firing is lost inside the ring, rather than in the beam dump, and can potentially damage a number of the LHC components. CERN specifications indicate a linear density of 6 x 106 protons over a 100 ns interval as the maximum charge safely allowed to accumulate in the abort gap at 7 TeV. We present a study of an abort gap monitor, based on a photomultiplier tube with a gated microchannel plate, which would allow for detecting such low charge densities by monitoring the synchrotron radiation emitted in the dedicated diagnostics port. We show results of beam test experiments at the Advanced Light Source (ALS) using a Hamamatsu 5961U MCP-PMT, which indicate that such an instrument has the required sensitivity to meet LHC specifications.
Date: July 1, 2004
Creator: Beche, J.-F.; Byrd, J.; De Santis, S.; Placidi, M.; Turner, W. & Zolotorev, M.
Partner: UNT Libraries Government Documents Department

Design of Injector Systems for LUX

Description: The LUX concept [1] for a superconducting recirculating linac based ultrafast x-ray facility features a unique high-brightness electron beam injector. The design of the injector complex that meets the baseline requirements for LUX is presented. A dual-rf gun injector provides both high-brightness electron beams to drive the cascaded, seeded harmonic generation VUV-soft x-ray FELs as well as the ultra- low-vertical emittance (''flat'') beams that radiate in hard x-ray spontaneous emission synchrotron beamlines. Details of the injector complex design and performance characteristics are presented. Contributions by the thermal emittance and optical pulse shaping to the beam emission at the photocathode and to the beam dynamics throughout the injector are presented. Techniques that seek to optimize the injector performance, as well as constraints that prevent straightforward optimization, are discussed.
Date: July 1, 2004
Creator: Lidia, Steven M.
Partner: UNT Libraries Government Documents Department

The Impact of Feed Preparation Acid Stoichiometry and Redox on Melt Rate for the SB3-Frit 418 Feed System

Description: Batch 2 (SB2) and Sludge Batch 3 (SB3), and implemented a frit change from Frit 320 to Frit 418This blended sludge batch has been designated SB3 although previously SRNL has called this new sludge batch SB2/3. A series of dry-fed tests (using the Melt Rate Furnace or MRF) and slurry fed tests (using the Slurry-Fed Melt Rate Furnace or SMRF) have been performed to investigate the effect of feed preparation acid stoichiometry and REDOX (Reduction/Oxidation) on the melt rate of the SB3 - Frit 418 system. With regards to acid stoichiometry, the current DWPF target of 155 gave a higher melt rate than the 185 when tested in the SMRF. This contradicted the MRF results for the first time that both melt systems were used to evaluate melt rate with various feeds. The SMRF results should be used as slurry-fed results are more representative of what would occur in the DWPF, especially since the variable tested did not change the final glass composition. With regard to changes in REDOX (0.0, 0.1, a nd 0.2), the MRF tests indicated no difference while the SMRF tests showed that melt rate was not negatively impacted until a REDOX below 0.1 was used. In addition, all SMRF acid stoichiometry and REDOX feeds tested were diluted from about 50 to 45 weight percent total solids after melt rates had been determined at 50 weight percent. In all cases the lower weight percent solids resulted in lower melt rates. Based on this testing, the Immobilization Technology Section (ITS) recommends that the DWPF continue to operate the feed preparation processing for SB3 with Frit 418 with a targeted acid stoichiometry of 155 and a targeted REDOX of 0.2. If needed for other process concerns, REDOX targets approaching 0.1 could be used at DWPF before melt rate would ...
Date: July 1, 2004
Creator: SMITH, MICHAEL
Partner: UNT Libraries Government Documents Department

High-Pressure Thermodynamic Properties of f-electron Metals, Transition Metal Oxides, and Half-Metallic Magnets

Description: This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (1) Mott transitions in transition metal oxides, (2) magnetism in half-metallic compounds, and (3) large volume-collapse transitions in f-band metals.
Date: July 1, 2004
Creator: Scalettar, Richard T. & Pickett, Warren E.
Partner: UNT Libraries Government Documents Department

Impact of Agricultural Practice on Regional Climate in a CoupledLand Surface Mesoscale Model

Description: The land surface has been shown to form strong feedbacks with climate due to linkages between atmospheric conditions and terrestrial ecosystem exchanges of energy, momentum, water, and trace gases. Although often ignored in modeling studies, land management itself may form significant feedbacks. Because crops are harvested earlier under drier conditions, regional air temperature, precipitation, and soil moisture, for example, affect harvest timing, particularly of rain-fed crops. This removal of vegetation alters the land surface characteristics and may, in turn, affect regional climate. We applied a coupled climate(MM5) and land-surface (LSM1) model to examine the effects of early and late winter wheat harvest on regional climate in the Department of Energy Atmospheric Radiation Measurement (ARM) Climate Research Facility in the Southern Great Plains, where winter wheat accounts for 20 percent of the land area. Within the winter wheat region, simulated 2 m air temperature was 1.3 C warmer in the Early Harvest scenario at mid-day averaged over the two weeks following harvest. Soils in the harvested area were drier and warmer in the top 10 cm and wetter in the 10-20 cm layer. Midday soils were 2.5 C warmer in the harvested area at mid-day averaged over the two weeks following harvest. Harvest also dramatically altered latent and sensible heat fluxes. Although differences between scenarios diminished once both scenarios were harvested, the short-term impacts of land management on climate were comparable to those from land cover change demonstrated in other studies.
Date: July 1, 2004
Creator: Cooley, H. S.; Riley, W. J.; Torn, M. S. & He, Y.
Partner: UNT Libraries Government Documents Department

The Impact of the Proposed delta Gp Limits on Glass Formulation Efforts: Part II. Experimental Results

Description: The Savannah River National Laboratory (SRNL) has initiated studies to assess alternative durability options that may provide access to compositional regions of interest in support of the accelerated cleanup mission at the Defense Waste Processing Facility (DWPF). One of the options being pursued is the redefinition of the durability model acceptability limits. Some of the conservative steps used in establishing the current limits without compromising the high confidence required for meeting the specification on the waste form quality were identified and eliminated. The results led to a set of three new Property Acceptability Region (PAR) values for the preliminary glass dissolution estimator that has the potential to allow access to compositional regions of interest to improve melt rate or waste loading. Although these limits are available for implementation, there is no driving force to do so with the current sludge batch (i.e., the current Frit 418 - Sludge Batch 3 (SB3) system is TL limited). The objectives of this task were to investigate (and generate) the incentive of applying the proposed durability limits in the Product Composition Control System (PCCS) from a glass formulation perspective. Glass compositions were identified or developed to transition into and through the region of GP acceptability as defined by the current and proposed durability limits. The progression through the newly defined acceptability region was accomplished by increasing the total alkali in the glass via higher alkali frits and/or waste loading (WL). The focus of this report is on the measured durability response as it compares to model predictions to assess the applicability and/or potential conservatism of the various limits or durability approaches. The normalized boron release values (NL [B] g/L) for the study glasses ranged from approximately 1.0 g/L to 2.0 g/L. The Product Consistency Test (PCT) responses provide evidence that implementation of the proposed ...
Date: July 1, 2004
Creator: PEELER, DAVID
Partner: UNT Libraries Government Documents Department

Towards attosecond X-ray pulses from the FEL

Description: The ability to study ultrafast phenomena has been recently advanced by the demonstrated production and measurement of a single, 650-attosecond (10{sup 18} sec), VUV x-ray pulse[1] and, latter, a 250-attosecond pulse[2]. The next frontier is a production of the x-ray pulses with shorter wavelengths and in a broader spectral range. Several techniques for a generation of an isolated, attosecond duration, short-wavelength x-ray pulse based upon the ponderomotive laser acceleration [3], SASE and harmonic cascade FELs ([4] - [6]) had been already proposed. In this paper we briefly review a technique proposed in [5] and present some new results.
Date: July 1, 2004
Creator: Zholents, Alexander A. & Fawley, William M.
Partner: UNT Libraries Government Documents Department

Coherent infrared radiation from the ALS generated via femtosecond laser modulation of the electron beam

Description: Interaction of an electron beam with a femtosecond laser pulse co-propagating through a wiggler at the ALS produces large modulation of the electron energies within a short {approx}100 fs slice of the electron bunch. Propagating around the storage ring, this bunch develops a longitudinal density perturbation due to the dispersion of electron trajectories. The length of the perturbation evolves with a distance from the wiggler but is much shorter than the electron bunch length. This perturbation causes the electron bunch to emit short pulses of temporally and spatially coherent infrared light which are automatically synchronized to the modulating laser. The intensity and spectra of the infrared light were measured in two storage ring locations for a nominal ALS lattice and for an experimental lattice with the higher momentum compaction factor. The onset of instability stimulated by laser e-beam interaction had been discovered. The infrared signal is now routinely used as a sensitive monitor for a fine tuning of the laser beam alignment during data accumulation in the experiments with femtosecond x-ray pulses.
Date: July 1, 2004
Creator: Byrd, J.M.; Hao, Z.; Martin, M.C.; Robin, D.S.; Sannibale, F.; Schoenlein, R.W. et al.
Partner: UNT Libraries Government Documents Department

Testing IH Instrumentation: Analysis of 1996-1998 Tank Ventilation Data in Terms of Characterizing a Transient Release

Description: An analysis is conducted of the 1996-1998 Hanford tank ventilation studies of average ventilation rates to help define characteristics of shorter term releases. This effort is being conducted as part of the design of tests of Industrial Hygiene’s (IH) instrumentation ability to detect transient airborne plumes from tanks using current deployment strategies for tank operations. This analysis has improved our understanding of the variability of hourly average tank ventilation processes. However, the analysis was unable to discern the relative importance of emissions due to continuous releases and short-duration bursts of material. The key findings are as follows: 1. The ventilation of relatively well-sealed, passively ventilated tanks appears to be driven by a combination of pressure, buoyancy, and wind influences. The results of a best-fit analysis conducted with a single data set provide information on the hourly emission variability that IH instrumentation will need to detect. 2. Tank ventilation rates and tank emission rates are not the same. The studies found that the measured infiltration rates for a single tank are often a complex function of air exchanges between tanks and air exchanges with outdoor air. This situation greatly limits the usefulness of the ventilation data in defining vapor emission rates. 3. There is no evidence in the data to discern if the routine tank vapor releases occur over a short time (i.e., a puff) or over an extended time (i.e., continuous releases). Based on this analysis of the tank ventilation studies, it is also noted that 1) the hourly averaged emission peaks from the relatively well-sealed passively-vented tanks (such as U-103) are not a simple function of one meteorological parameter – but the peaks often are the result of the coincidence of temporal maximums in pressure, temperature, and wind influences and 2) a mechanistic combination modeling approach and/or field studies ...
Date: July 1, 2004
Creator: Droppo, James G.
Partner: UNT Libraries Government Documents Department

The Impact of Proposed delta Gp Limits on Glass Formulation Efforts: Part 1:. Model-Based Assessments

Description: The Savannah River National Laboratory (SRNL) has initiated studies to assess alternative durability options that may provide access to compositional regions of interest in support of the accelerated cleanup mission at the Defense Waste Processing Facility (DWPF). One of the options being pursued is the redefinition of the durability model acceptability limits. Some of the conservative steps used in establishing the current limits without comprising the high confidence required for meeting the specification on the wasteform quality were identified and eliminated. The results led to a set of three new Property Acceptability Region (PAR) values for the preliminary glass dissolution estimator or free energy of hydration durability model which have the potential to allow access to compositional regions of interest to improve melt rate or waste throughput. Although these limits are available for implementation, there is currently no driving force to do so (i.e., the current Frit 418 - Sludge Batch 3 (SB3) system is liquidus temperature (TL) limited). In this report, glass formulations were identified with the intent of generating incentive for applying the new durability limits for SB3. More specifically, higher alkali frit compositions were identified or developed to transition into and through the region of .Gp acceptability as defined by the current and proposed durability limits. All other property prediction criteria were satisfied. An eight glass test matrix has been identified to meet these objectives. These glasses will be fabricated in the laboratory and their durability measured and compared to model predictions (and to the assessments by the index system). Although incentive for implementation of the proposed durability limits could be demonstrated through the measured durability response for these higher alkali systems, assessments of melt rate should also be performed to establish a clear motive or driver to implement a frit change. More specifically, a ''significant'' increase ...
Date: July 1, 2004
Creator: PEELER, DAVID
Partner: UNT Libraries Government Documents Department