4-wave mixing for phase-matching free nonlinear optics in quantum cascade structures : LDRD 08-0346 final report. (open access)

4-wave mixing for phase-matching free nonlinear optics in quantum cascade structures : LDRD 08-0346 final report.

Optical nonlinearities and quantum coherences have the potential to enable efficient, high-temperature generation of coherent THz radiation. This LDRD proposal involves the exploration of the underlying physics using intersubband transitions in a quantum cascade structure. Success in the device physics aspect will give Sandia the state-of-the-art technology for high-temperature THz quantum cascade lasers. These lasers are useful for imaging and spectroscopy in medicine and national defense. Success may have other far-reaching consequences. Results from the in-depth study of coherences, dephasing and dynamics will eventually impact the fields of quantum computing, optical communication and cryptology, especially if we are successful in demonstrating entangled photons or slow light. An even farther reaching development is if we can show that the QC nanostructure, with its discrete atom-like intersubband resonances, can replace the atom in quantum optics experiments. Having such an 'artificial atom' will greatly improve flexibility and preciseness in experiments, thereby enhancing the discovery of new physics. This is because we will no longer be constrained by what natural can provide. Rather, one will be able to tailor transition energies and optical matrix elements to enhance the physics of interest. This report summarizes a 3-year LDRD program at Sandia National Laboratories exploring optical …
Date: October 1, 2010
Creator: Chow, Weng Wah; Wanke, Michael Clement; Allen, Dan G.; Yang, Zhenshan & Waldmueller, Ines
Object Type: Report
System: The UNT Digital Library

Accelerated Testing and On-Sun Failure of CPV Die-Attach

Accelerated Testing and On-Sun Failure of CPV Die-attach. Presentation on CPV accelerated reliability testing.
Date: October 1, 2010
Creator: Bosco, N.; Kurtz, S. & Stokes, A.
Object Type: Presentation
System: The UNT Digital Library
Active infrared materials for beam steering. (open access)

Active infrared materials for beam steering.

The mid-infrared (mid-IR, 3 {micro}m -12 {micro}m) is a highly desirable spectral range for imaging and environmental sensing. We propose to develop a new class of mid-IR devices, based on plasmonic and metamaterial concepts, that are dynamically controlled by tunable semiconductor plasma resonances. It is well known that any material resonance (phonons, excitons, electron plasma) impacts dielectric properties; our primary challenge is to implement the tuning of a semiconductor plasma resonance with a voltage bias. We have demonstrated passive tuning of both plasmonic and metamaterial structures in the mid-IR using semiconductors plasmas. In the mid-IR, semiconductor carrier densities on the order of 5E17cm{sup -3} to 2E18cm{sup -3} are desirable for tuning effects. Gate control of carrier densities at the high end of this range is at or near the limit of what has been demonstrated in literature for transistor style devices. Combined with the fact that we are exploiting the optical properties of the device layers, rather than electrical, we are entering into interesting territory that has not been significantly explored to date.
Date: October 1, 2010
Creator: Brener, Igal; Reno, John Louis; Passmore, Brandon Scott; Gin, Aaron V.; Shaner, Eric Arthur; Miao, Xiaoyu et al.
Object Type: Report
System: The UNT Digital Library
Advanced analysis methods in particle physics (open access)

Advanced analysis methods in particle physics

Each generation of high energy physics experiments is grander in scale than the previous - more powerful, more complex and more demanding in terms of data handling and analysis. The spectacular performance of the Tevatron and the beginning of operations of the Large Hadron Collider, have placed us at the threshold of a new era in particle physics. The discovery of the Higgs boson or another agent of electroweak symmetry breaking and evidence of new physics may be just around the corner. The greatest challenge in these pursuits is to extract the extremely rare signals, if any, from huge backgrounds arising from known physics processes. The use of advanced analysis techniques is crucial in achieving this goal. In this review, I discuss the concepts of optimal analysis, some important advanced analysis methods and a few examples. The judicious use of these advanced methods should enable new discoveries and produce results with better precision, robustness and clarity.
Date: October 1, 2010
Creator: Bhat, Pushpalatha C.
Object Type: Article
System: The UNT Digital Library
Advanced Fuels Campaign Execution Plan (open access)

Advanced Fuels Campaign Execution Plan

The purpose of the Advanced Fuels Campaign (AFC) Execution Plan is to communicate the structure and management of research, development, and demonstration (RD&D) activities within the Fuel Cycle Research and Development (FCRD) program. Included in this document is an overview of the FCRD program, a description of the difference between revolutionary and evolutionary approaches to nuclear fuel development, the meaning of science-based development of nuclear fuels, and the “Grand Challenge” for the AFC that would, if achieved, provide a transformational technology to the nuclear industry in the form of a high performance, high reliability nuclear fuel system. The activities that will be conducted by the AFC to achieve success towards this grand challenge are described and the goals and milestones over the next 20 to 40 year period of research and development are established.
Date: October 1, 2010
Creator: Pasamehmetoglu, Kemal
Object Type: Report
System: The UNT Digital Library
Advanced Unit Commitment Strategies for the U.S. Eastern Interconnection: Preprint (open access)

Advanced Unit Commitment Strategies for the U.S. Eastern Interconnection: Preprint

This paper outlines a study undertaken for the U.S. Eastern Interconnection in which different advanced unit commitment strategies were simulated for three different years to evaluate the benefits that may occur from using these strategies as an operational tool.
Date: October 1, 2010
Creator: Ela, E.; Milligan, M.; Meibom, P.; Barth, R. & Tuohy, A.
Object Type: Article
System: The UNT Digital Library
ADVANCING REACTIVE TRACER METHODS FOR MONITORING THERMAL DRAWDOWN IN GEOTHERMAL ENHANCED GEOTHERMAL RESERVOIRS (open access)

ADVANCING REACTIVE TRACER METHODS FOR MONITORING THERMAL DRAWDOWN IN GEOTHERMAL ENHANCED GEOTHERMAL RESERVOIRS

Reactive tracers have long been considered a possible means of measuring thermal drawdown in a geothermal system, before significant cooling occurs at the extraction well. Here, we examine the sensitivity of the proposed method to evaluate reservoir cooling and demonstrate that while the sensitivity of the method as generally proposed is low, it may be practical under certain conditions.
Date: October 1, 2010
Creator: Plummer, Mitchell A.; Palmer, Carl D.; Mattson, Earl D.; Redden, George D. & Hull, Laurence C.
Object Type: Article
System: The UNT Digital Library
Aerosol cluster impact and break-up : model and implementation. (open access)

Aerosol cluster impact and break-up : model and implementation.

In this report a model for simulating aerosol cluster impact with rigid walls is presented. The model is based on JKR adhesion theory and is implemented as an enhancement to the granular (DEM) package within the LAMMPS code. The theory behind the model is outlined and preliminary results are shown. Modeling the interactions of small particles is relevant to a number of applications (e.g., soils, powders, colloidal suspensions, etc.). Modeling the behavior of aerosol particles during agglomeration and cluster dynamics upon impact with a wall is of particular interest. In this report we describe preliminary efforts to develop and implement physical models for aerosol particle interactions. Future work will consist of deploying these models to simulate aerosol cluster behavior upon impact with a rigid wall for the purpose of developing relationships for impact speed and probability of stick/bounce/break-up as well as to assess the distribution of cluster sizes if break-up occurs. These relationships will be developed consistent with the need for inputs into system-level codes. Section 2 gives background and details on the physical model as well as implementations issues. Section 3 presents some preliminary results which lead to discussion in Section 4 of future plans.
Date: October 1, 2010
Creator: Lechman, Jeremy B.
Object Type: Report
System: The UNT Digital Library
Air Shipment of Spent Nuclear Fuel from Romania to Russia (open access)

Air Shipment of Spent Nuclear Fuel from Romania to Russia

Romania successfully completed the world’s first air shipment of spent nuclear fuel transported in Type B(U) casks under existing international laws and without shipment license special exceptions when the last Romanian highly enriched uranium (HEU) spent nuclear fuel was transported to the Russian Federation in June 2009. This air shipment required the design, fabrication, and licensing of special 20 foot freight containers and cask tiedown supports to transport the eighteen TUK 19 shipping casks on a Russian commercial cargo aircraft. The new equipment was certified for transport by road, rail, water, and air to provide multi modal transport capabilities for shipping research reactor spent fuel. The equipment design, safety analyses, and fabrication were performed in the Russian Federation and transport licenses were issued by both the Russian and Romanian regulatory authorities. The spent fuel was transported by truck from the VVR S research reactor to the Bucharest airport, flown by commercial cargo aircraft to the airport at Yekaterinburg, Russia, and then transported by truck to the final destination in a secure nuclear facility at Chelyabinsk, Russia. This shipment of 23.7 kg of HEU was coordinated by the Russian Research Reactor Fuel Return Program (RRRFR), as part of the U.S. Department …
Date: October 1, 2010
Creator: Bolshinsky, Igor; Allen, Ken; Biro, Lucian & Buchelnikov, Alexander
Object Type: Article
System: The UNT Digital Library
Algorithms Performance Investigation of a Generalized Spreader-Bar Detection System (open access)

Algorithms Performance Investigation of a Generalized Spreader-Bar Detection System

A “generic” gantry-crane-mounted spreader bar detector has been simulated in the Monte-Carlo radiation transport code MCNP [1]. This model is intended to represent the largest realistically feasible number of detector crystals in a single gantry-crane model intended to sit atop an InterModal Cargo Container (IMCC). Detectors were chosen from among large commonly-available sodium iodide (NaI) crystal scintillators and spaced as evenly as is thought possible with a detector apparatus attached to a gantry crane. Several scenarios were simulated with this model, based on a single IMCC being moved between a ship’s deck or cargo hold and the dock. During measurement, the gantry crane will carry that IMCC through the air and lower it onto a receiving vehicle (e.g. a chassis or a bomb cart). The case of an IMCC being moved through the air from an unknown radiological environment to the ground is somewhat complex; for this initial study a single location was picked at which to simulate background. An HEU source based on earlier validated models was used, and placed at varying depths in a wood cargo. Many statistical realizations of these scenarios are constructed from simulations of the component spectra, simulated to have high statistics. The resultant data …
Date: October 1, 2010
Creator: Robinson, Sean M.; Ashbaker, Eric D.; Hensley, Walter K.; Schweppe, John E.; Sandness, Gerald A.; Erikson, Luke E. et al.
Object Type: Report
System: The UNT Digital Library
Analysis of Federal Subsidies: Implied Price of Carbon (open access)

Analysis of Federal Subsidies: Implied Price of Carbon

For informed climate change policy, it is important for decision makers to be able to assess how the costs and benefits of federal energy subsidies are distributed and to be able to have some measure to compare them. One way to do this is to evaluate the implied price of carbon (IPC) for a federal subsidy, or set of subsidies; where the IPC is the cost of the subsidy to the U.S. Treasury divided by the emissions reductions it generated. Subsidies with lower IPC are more cost effective at reducing greenhouse gas emissions, while subsidies with a negative IPC act to increase emissions. While simple in concept, the IPC is difficult to calculate in practice. Calculation of the IPC requires knowledge of (i) the amount of energy associated with the subsidy, (ii) the amount and type of energy that would have been produced in the absence of the subsidy, and (iii) the greenhouse gas emissions associated with both the subsidized energy and the potential replacement energy. These pieces of information are not consistently available for federal subsidies, and there is considerable uncertainty in cases where the information is available. Thus, exact values for the IPC based upon fully consistent standards …
Date: October 1, 2010
Creator: Cooper, D. Craig & Foulke, Thomas
Object Type: Report
System: The UNT Digital Library
Annual Site Environmental Report: 2009(ASER) (open access)

Annual Site Environmental Report: 2009(ASER)

This report provides information about environmental programs during the calendar year of 2009 at the SLAC National Accelerator Laboratory (SLAC), Menlo Park, California. Activities that span the calendar year, i.e., stormwater monitoring covering the winter season of 2009/2010 (October 2009 through May 2010), are also included. Production of an annual site environmental report (ASER) is a requirement established by the United States Department of Energy (DOE) for all management and operating (M&O) contractors throughout the DOE complex. SLAC is a federally-funded research and development center with Stanford University as the M&O contractor. Under Executive Order (EO) 13423, Strengthening Federal Environmental, Energy, and Transportation Management, EO 13514, Federal Leadership in Environmental, Energy, and Economic Performance, and DOE Order 450.1A, Environmental Protection Program, SLAC effectively implements and integrates the key elements of an Environmental Management System (EMS) to achieve the site's integrated safety and environmental management system goals. For normal daily activities, SLAC managers and supervisors are responsible for ensuring that policies and procedures are understood and followed so that Worker safety and health are protected, The environment is protected, and Compliance is ensured. Throughout 2009, SLAC continued to improve its management systems. These systems provided a structured framework for SLAC to …
Date: October 1, 2010
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Application of a localized chaos by rf-phase modulations in phase-space dilution (open access)

Application of a localized chaos by rf-phase modulations in phase-space dilution

Physics of chaos in a localized phase-space region is exploited to produce a longitudinally uniformly distributed beam. Theoretical study and simulations are used to study its origin and applicability in phase-space dilution of beam bunch. Through phase modulation to a double-rf system, a central region of localized chaos bounded by invariant tori are generated by overlapping parametric resonances. Condition and stability of the chaos will be analyzed. Applications include high-power beam, beam distribution uniformization, and industrial beam irradiation.
Date: October 1, 2010
Creator: Lee, S. Y. & Ng, K. Y.
Object Type: Article
System: The UNT Digital Library
Architecture of a Silicon Strip Beam Position Monitor (open access)

Architecture of a Silicon Strip Beam Position Monitor

A collaboration between Fermilab and the Institute for High Energy Physics (IHEP), Beijing, has developed a beam position monitor for the IHEP test beam facility. This telescope is based on 5 stations of silicon strip detectors having a pitch of 60 microns. The total active area of each layer of the detector is about 12 x 10 cm{sup 2}. Readout of the strips is provided through the use of VA1 ASICs mounted on custom hybrid printed circuit boards and interfaced to Adapter Cards via copper-over-kapton flexible circuits. The Adapter Cards amplify and level-shift the signal for input to the Fermilab CAPTAN data acquisition nodes for data readout and channel configuration. These nodes deliver readout and temperature data from triggered events to an analysis computer over gigabit Ethernet links.
Date: October 1, 2010
Creator: Angstadt, R.; Cooper, W.; Demarteau, M.; Green, J.; Jakubowski, S.; Prosser, A. et al.
Object Type: Article
System: The UNT Digital Library
ASER- Environmental Monitoring on the ORR:  2009 Results (open access)

ASER- Environmental Monitoring on the ORR: 2009 Results

This report talks about Environmental Monitoring on the ORR
Date: October 1, 2010
Creator: Loffman, Regis S.
Object Type: Report
System: The UNT Digital Library
Assessing the Impact of Heat Rejection Technology on CSP Plant Revenue: Preprint (open access)

Assessing the Impact of Heat Rejection Technology on CSP Plant Revenue: Preprint

This paper explores the impact of cooling technology on revenue for hybrid-cooled plants with varying wet cooling penetration for four representative locations in the American Southwest. The impact of ACC design-point initial temperature difference (ITD - the difference between the condensing steam temperature and ambient dry-bulb) is also included in the analysis.
Date: October 1, 2010
Creator: Wagner, M. J. & Kutscher, C. F.
Object Type: Article
System: The UNT Digital Library
Automating Risk Assessments of Hazardous Material Shipments for Transportation Routes and Mode Selection (open access)

Automating Risk Assessments of Hazardous Material Shipments for Transportation Routes and Mode Selection

The METEOR project at Idaho National Laboratory (INL) successfully addresses the difficult problem in risk assessment analyses of combining the results from bounding deterministic simulation results with probabilistic (Monte Carlo) risk assessment techniques. This paper describes a software suite designed to perform sensitivity and cost/benefit analyses on selected transportation routes and vehicles to minimize risk associated with the shipment of hazardous materials. METEOR uses Monte Carlo techniques to estimate the probability of an accidental release of a hazardous substance along a proposed transportation route. A METEOR user selects the mode of transportation, origin and destination points, and charts the route using interactive graphics. Inputs to METEOR (many selections built in) include crash rates for the specific aircraft, soil/rock type and population densities over the proposed route, and bounding limits for potential accident types (velocity, temperature, etc.). New vehicle, materials, and location data are added when available. If the risk estimates are unacceptable, the risks associated with alternate transportation modes or routes can be quickly evaluated and compared. Systematic optimizing methods will provide the user with the route and vehicle selection identified with the lowest risk of hazardous material release. The effects of a selected range of potential accidents such as …
Date: October 1, 2010
Creator: Dolphin, Barbara H.; RIchins, William D. & Novascone, Stephen R.
Object Type: Article
System: The UNT Digital Library
Baseline for Climate Change: Modeling Watershed Aquatic Biodiversity Relative to Environmental and Anthropogenic Factors (open access)

Baseline for Climate Change: Modeling Watershed Aquatic Biodiversity Relative to Environmental and Anthropogenic Factors

Objectives of the two-year study were to (1) establish baselines for fish and macroinvertebrate community structures in two mid-Atlantic lower Piedmont watersheds (Quantico Creek, a pristine forest watershed; and Cameron Run, an urban watershed, Virginia) that can be used to monitor changes relative to the impacts related to climate change in the future; (2) create mathematical expressions to model fish species richness and diversity, and macroinvertebrate taxa and macroinvertebrate functional feeding group taxa richness and diversity that can serve as a baseline for future comparisons in these and other watersheds in the mid-Atlantic region; and (3) heighten people’s awareness, knowledge and understanding of climate change and impacts on watersheds in a laboratory experience and interactive exhibits, through internship opportunities for undergraduate and graduate students, a week-long teacher workshop, and a website about climate change and watersheds. Mathematical expressions modeled fish and macroinvertebrate richness and diversity accurately well during most of the six thermal seasons where sample sizes were robust. Additionally, hydrologic models provide the basis for estimating flows under varying meteorological conditions and landscape changes. Continuations of long-term studies are requisite for accurately teasing local human influences (e.g. urbanization and watershed alteration) from global anthropogenic impacts (e.g. climate change) on …
Date: October 1, 2010
Creator: Maurakis, Eugene G
Object Type: Report
System: The UNT Digital Library
Basin-Scale Opportunity Assessment Initiative Background Literature Review (open access)

Basin-Scale Opportunity Assessment Initiative Background Literature Review

As called for in the March 24, 2010, Memorandum of Understanding (MOU) for Hydropower, the U.S. Department of Energy (DOE), the U.S. Department of the Interior (DOI), the U.S. Army Corps of Engineers (USACE), environmental stakeholders, and the hydropower industry are collaborating to identify opportunities to simultaneously increase electricity generation and improve environmental services in river basins of the United States. New analytical tools provide an improved ability to understand, model, and visualize environmental and hydropower systems. Efficiencies and opportunities that might not be apparent in site-by-site analyses can be revealed through assessments at the river-basin scale. Information from basin-scale assessments could lead to better coordination of existing hydropower projects, or to inform siting decisions (e.g., balancing the removal of some dams with the construction of others), in order to meet renewable energy production and environmental goals. Basin-scale opportunity assessments would inform energy and environmental planning and address the cumulative effects of hydropower development and operations on river basin environmental quality in a way that quantifies energy-environment tradeoffs. Opportunity assessments would create information products, develop scenarios, and identify specific actions that agencies, developers, and stakeholders can take to locate new sustainable hydropower projects, increase the efficiency and environmental performance of …
Date: October 1, 2010
Creator: Saulsbury, Bo; Geerlofs, Simon H.; Cada, Glenn F & Bevelhimer, Mark S
Object Type: Report
System: The UNT Digital Library
Benefit of Regional Energy Balancing Service on Wind Integration in the Western Interconnection of the United States: Preprint (open access)

Benefit of Regional Energy Balancing Service on Wind Integration in the Western Interconnection of the United States: Preprint

This analysis indicates the extent to which pooled regional dispatch for matching generation to load mitigates the costs and improves associated reliability, particularly in scenarios with high penetration of variable output resources, such as wind
Date: October 1, 2010
Creator: Milligan, M.; Kirby, B.; King, J. & Beuning, S.
Object Type: Article
System: The UNT Digital Library
Beyond the Inventory: An Interagency Collaboration to Reduce Greenhouse Gas Emissions in the Greater Yellowstone Area (open access)

Beyond the Inventory: An Interagency Collaboration to Reduce Greenhouse Gas Emissions in the Greater Yellowstone Area

As one of the largest, intact ecosystems in the continental United States, land managers within the Greater Yellowstone Area (GYA) have recognized the importance of compiling and understanding agency greenhouse gas (GHG) emissions. The 10 Federal units within the GYA have taken an active role in compiling GHG inventories on a unit- and ecosystem-wide level, setting goals for GHG mitigation, and identifying mitigation strategies for achieving those goals. This paper details the processes, methodologies, challenges, solutions, and lessons learned by the 10 Federal units within the GYA throughout this ongoing effort.
Date: October 1, 2010
Creator: Kandt, A.; Hotchkiss, E. & Fiebig, M.
Object Type: Report
System: The UNT Digital Library
Bi-Annual Report 2010-2011: Shaping pulse flows to meet environmental and energy objectives (open access)

Bi-Annual Report 2010-2011: Shaping pulse flows to meet environmental and energy objectives

This report describes a bioenergetic model developed to allocate seasonal pulse flows to benefit salmon growth. The model links flow with floodplain inundation and production of invertebrate prey eaten by juvenile Chinook salmon. A unique quantile modeling approach is used to describe temporal variation among juvenile salmon spawned at different times. Preliminary model outputs are presented and future plans to optimize flows both to maximize salmon growth and hydropower production are outlined.
Date: October 1, 2010
Creator: Jager, Yetta
Object Type: Report
System: The UNT Digital Library
Building America House Simulation Protocols (Revised) (open access)

Building America House Simulation Protocols (Revised)

The House Simulation Protocol document was developed to track and manage progress toward Building America's multi-year, average whole-building energy reduction research goals for new construction and existing homes, using a consistent analytical reference point. This report summarizes the guidelines for developing and reporting these analytical results in a consistent and meaningful manner for all home energy uses using standard operating conditions.
Date: October 1, 2010
Creator: Hendron, R. & Engebrecht, C.
Object Type: Report
System: The UNT Digital Library
Bypass Flow Computations using a One-Twelfth Symmetric Sector For Normal Operation in a 350 MWth VHTR (open access)

Bypass Flow Computations using a One-Twelfth Symmetric Sector For Normal Operation in a 350 MWth VHTR

Significant uncertainty exists about the effects of bypass flow in a prismatic gas-cooled very high temperature reactor (VHTR). Bypass flow is the flow in the gaps between prismatic graphite blocks in the core. The gaps are present because of variations in their construction, imperfect installation and expansion and shrinkage from thermal heating and neutron fluence. Calculations are performed using computational fluid dynamics (CFD) for flow of the helium coolant in the gap and coolant channels along with conjugate heat generation and heat transfer in the fuel compacts and graphite. A commercial CFD code is used for all of the computations. A one-twelfth sector of a standard hexagonal block column is used for the CFD model because of its symmetry. Various scenarios are computed by varying the gap width from zero to 5 mm, varying the total heat generation rate to examine average and peak radial generation rates and variation of the graphite block geometry to account for the effects of shrinkage caused by irradiation. The calculations are for a 350 MWth prismatic reactor. It is shown that the effect of increasing gap width, while maintaining the same total mass flow rate, causes increased maximum fuel temperature while providing significant cooling …
Date: October 1, 2010
Creator: Johnson, Richard W. & Sato, Hiroyuki
Object Type: Article
System: The UNT Digital Library