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Analysis of BLT data from VKI Longshot Facility

Wagnild, Ross M.

Results for the stability analysis are as follows: maximum N factor trends agree well with previous data; transition N factor difference between Case 2 and Case 3 disagrees with previous data. Requires another look; predicts disturbance frequencies that agree with experiments and VESTA computations; and predicts larger N factors than VESTA

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TYPE Other Report YEAR 2014
DOIOSTI

Frequency Translation to Demonstrate a Hybrid Quantum Architecture: Final Report

Clark, Susan M.; Fortier, Kevin; El-Kady, Ihab F.; Mcguinness, Hayden J.E.; Stick, Daniel L.; Reinke, Charles M.

The Frequency Translation to Demonstrate a Hybrid Quantum Architecture project focused on developing nonlinear optics to couple two different ion species and make their emitted UV photons indistinguishable. Successful demonstration of photonic coupling of different ion species lays the foundation for coupling drastically different types of qubits, such as ions and quantum dots. Frequency conversion of single photons emitted from single ions remains a "hot" topic with many groups pursing this effort; however due to challenges in producing short period periodically poled crystal it has yet to be realized. This report details the efforts of trying to frequency convert single photons emitted from trapped ions to other wavelengths. We present our theoretical studies of candidate platforms for frequency conversion: photonic crystal fibers, X(2) nonlinear crystals in optical cavities, and photonic crystal cavities. We also present experiment results in ion trapping X(2) nonlinear crystals measurements and photonic crystal fabrication

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TYPE SAND Report YEAR 2014
DOIOSTI

Aleph Field Solver Challenge Problem Results Summary

Hooper, Russell; Moore, Stan G.

Aleph models continuum electrostatic and steady and transient thermal fields using a finite-element method. Much work has gone into expanding the core solver capability to support enriched modeling consisting of multiple interacting fields, special boundary conditions and two-way interfacial coupling with particles modeled using Aleph's complementary particle-in-cell capability. This report provides quantitative evidence for correct implementation of Aleph's field solver via order- of-convergence assessments on a collection of problems of increasing complexity. It is intended to provide Aleph with a pedigree and to establish a basis for confidence in results for more challenging problems important to Sandia's mission that Aleph was specifically designed to address.

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TYPE SAND Report YEAR 2014
DOIOSTI

Aleph code electrostatic solver verification

Bettencourt, Matthew T.

Aleph is an electrostatic particle-in-cell code which uses the finite element method to solve for the electric potential and field based on external potentials and discrete charged particles. The field solver in Aleph was verified for two problems and matched the analytic theory for finite elements. The first problem showed the mesh-refinement convergence for a nonlinear field with no particles within the domain. This matched the theoretical convergence rates of second order for the potential field and first order for the electric field. Then the solution for a single particle in an infinite domain was compared to the analytic solution. This also matched the theory of first order convergence in both the potential and electric fields for both problems over a refinement factor of 16. These solutions give confidence that the field solver and charge weighting schemes are implemented correctly. This page intentionally left blank.

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TYPE SAND Report YEAR 2014
DOIOSTI

Competing Quantum Hall Phases in the Second Landau Level in Low Density Limit

Pan, Wei; Serafin, A.; Xia, J.S.; Liang, Y.; Sullivan, N.S.; Baldwin, K.W.; West, K.W.; Pfeiffer, L.N.; Tsui, D.C.

Up to date, studies of the fractional quantum Hall effect (FQHE) states in the second Landau level have mainly been carried out in the high electron density regime, where the electron mobility is the highest. Only recently, with the advance of high quality low density MBE growth, experiments have been pushed to the low density regime [1], where the electron-electron interactions are strong and the Landau level mixing parameter, defined by κ = e2/εIB/ℏωe, is large. Here, lB = (ℏe/B)1/2 is the magnetic length and ωc = eB/m the cyclotron frequency. All other parameters have their normal meanings. It has been shown that a large Landau level mixing effect strongly affects the electron physics in the second Landau level [2].

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TYPE Other Report YEAR 2014
DOIOSTI

Coupled optical/thermal/fluid analysis and design requirements for operation and testing of a supercritical CO2 solar receiver

Khivsara, Sagar

Recent studies have evaluated closed-loop supercritical carbon dioxide (s-CO2) Brayton cycles to be a higher energy-density system in comparison to conventional superheated steam Rankine systems. At turbine inlet conditions of 923K and 25 MPa, high thermal efficiency (~50%) can be achieved. Achieving these high efficiencies will make concentrating solar power (CSP) technologies a competitive alternative to current power generation methods. To incorporate a s-CO2 Brayton power cycle in a solar power tower system, the development of a solar receiver capable of providing an outlet temperature of 923 K (at 25 MPa) is necessary. To satisfy the temperature requirements of a s-CO2 Brayton cycle with recuperation and recompression, it is required to heat s-CO2 by a temperature of ~200 K as it passes through the solar receiver. Our objective was to develop an optical-thermal-fluid model to design and evaluate a tubular receiver that will receive a heat input ~1 MWth from a heliostat field. We also undertook the documentation of design requirements for the development, testing and safe operation of a direct s-CO2 solar receiver. The main purpose of this document is to serve as a reference and guideline for design and testing requirements, as well as to address the technical challenges and provide initial parameters for the computational models that will be employed for the development of s-CO2 receivers.

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TYPE Other Report YEAR 2014
DOIOSTI

Integrated Vulnerability and Impacts Assessment for Natural and Engineered Water-Energy Systems in the Southwest and Southern Rocky Mountain Region

Tidwell, Vincent C.; Wolfsberg, Andrew; Macknick, Jordan; Middleton, Richard

In the Southwest and Southern Rocky Mountains (SWSRM), energy production, energy resource extraction, and other high volume uses depend on water supply from systems that are highly vulnerable to extreme, coupled hydro-ecosystem-climate events including prolonged drought, flooding, degrading snow cover, forest die off, and wildfire. These vulnerabilities, which increase under climate change, present a challenge for energy and resource planners in the region with the highest population growth rate in the nation. Currently, analytical tools are designed to address individual aspects of these regional energy and water vulnerabilities. Further, these tools are not linked, severely limiting the effectiveness of each individual tool. Linking established tools, which have varying degrees of spatial and temporal resolution as well as modeling objectives, and developing next-generation capabilities where needed would provide a unique and replicable platform for regional analyses of climate-water-ecosystem-energy interactions, while leveraging prior investments and current expertise (both within DOE and across other Federal agencies).

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TYPE Other Report YEAR 2014
DOIOSTI

Proceedings of the 5th US/German Workshop on Salt Repository Research Design and Operation

Hansen, Francis D.; Snl; Leigh, Christi; Steininger, W.K.; Bollingerfehr, Wilhelm; Von Berlepsche, Thilo; Technology, Dbe

The 5th US/German Workshop on Salt Repository Research, Design, and Operation was held in Santa Fe New Mexico September 8-10, 2014. The forty seven registered participants were equally divided between the United States (US) and Germany, with one participant from The Netherlands. The agenda for the 2014 workshop was under development immediately upon finishing the 4th Workshop. Ongoing, fundamental topics such as thermomechanical behavior of salt, plugging and sealing, the safety case, and performance assessment continue to advance the basis for disposal of heat-generating nuclear waste in salt formations. The utility of a salt underground research laboratory (URL) remains an intriguing concept engendering discussion of testing protocol. By far the most interest in this years’ workshop pertained to operational safety. Given events at the Waste Isolation Pilot Plant (WIPP), this discussion took on a new sense of relevance and urgency.

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TYPE Other Report YEAR 2014
DOIOSTI

Stockham Waste Management Contract SOW

Stockham, Dwight J.

Sandia National Laboratories, New Mexico (SNL/NM) is a multi-program Research and Development Facility, owned by the Department of Energy (DOE) and operated by Sandia Corporation, a Lockheed Martin Company (LMC). Sandia waste management operations include radioactive and mixed waste and hazardous waste (including classified and explosive). Waste management activities include managing and characterizing the waste, completing waste disposal requests, and providing guidance on sorting, packaging, & storing wastes, preparing all necessary disposal request documents, and/or recycling, maintaining accurate records, help the line organizations in assuring the compliance of all waste management activities, and preparing compliance-related documentation. Additional contaminants may include polychlorinated biphenyls (PCBs), asbestos, and beryllium. Some radioactive and hazardous waste may also be managed as classified waste.

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TYPE SAND Report YEAR 2014
DOIOSTI

Experiments to Populate and Validate a Processing Model for Polyurethane Foam: Additional Data for Structural Foams

Rao, Rekha R.; Celina, Mathew C.; Giron, Nicholas H.; Long, Kevin N.; Russick, Edward M.

We are developing computational models to help understand manufacturing processes, final properties and aging of structural foam, polyurethane PMDI. Th e resulting model predictions of density and cure gradients from the manufacturing process will be used as input to foam heat transfer and mechanical models. BKC 44306 PMDI-10 and BKC 44307 PMDI-18 are the most prevalent foams used in structural parts. Experiments needed to parameterize models of the reaction kinetics and the equations of motion during the foam blowing stages were described for BKC 44306 PMDI-10 in the first of this report series (Mondy et al. 2014). BKC 44307 PMDI-18 is a new foam that will be used to make relatively dense structural supports via over packing. It uses a different catalyst than those in the BKC 44306 family of foams; hence, we expect that the reaction kineti cs models must be modified. Here we detail the experiments needed to characteriz e the reaction kinetics of BKC 44307 PMDI-18 and suggest parameters for the model based on these experiments. In additi on, the second part of this report describes data taken to provide input to the preliminary nonlinear visco elastic structural response model developed for BKC 44306 PMDI-10 foam. We show that the standard cu re schedule used by KCP does not fully cure the material, and, upon temperature elevation above 150°C, oxidation or decomposition reactions occur that alter the composition of the foam. These findings suggest that achieving a fully cured foam part with this formulation may be not be possible through therma l curing. As such, visco elastic characterization procedures developed for curing thermosets can provide only approximate material properties, since the state of the material continuously evolves during tests.

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TYPE SAND Report YEAR 2014
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Risk Management for Sodium Fast Reactors

Denman, Matthew R.; Groth, Katrina M.; Cardoni, Jeffrey; Wheeler, Timothy A.

Accident management is an important component to maintaining risk at acceptable levels for all complex systems, such as nuclear power plants. With the introduction of self - correcting, or inherently safe, reactor designs the focus has shifted from management by operators to allowing the syste m's design to manage the accident. While inherently and passively safe designs are laudable, extreme boundary conditions can interfere with the design attributes which facilitate inherent safety , thus resulting in unanticipated and undesirable end states. This report examines an inherently safe and small sodium fast reactor experiencing a beyond design basis seismic event with the intend of exploring two issues : (1) can human intervention either improve or worsen the potential end states and (2) can a Bayes ian Network be constructed to infer the state of the reactor to inform (1). ACKNOWLEDGEMENTS The author s would like to acknowledge the U.S. Department of E nergy's Office of Nuclear Energy for funding this research through Work Package SR - 14SN100303 under the Advanced Reactor Concepts program. The authors also acknowledge the PRA teams at A rgonne N ational L aborator y , O ak R idge N ational L aborator y , and I daho N ational L aborator y for their continue d contributions to the advanced reactor PRA mission area.

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TYPE SAND Report YEAR 2014
DOIOSTI
Results 50101–50200 of 99,299
Results 50101–50200 of 99,299