Comparing Linear Microinstability of the National Compact Stellarator Expriment and a Shaped Tokamak (open access)

Comparing Linear Microinstability of the National Compact Stellarator Expriment and a Shaped Tokamak

One metric for comparing con nement properties of di erent magnetic fusion energy con gurations is the linear critical gradient of drift wave modes. The critical gradient scale length determines the ratio of the core to pedestal temperature when a plasma is limited to marginal stability in the plasma core. The gyrokinetic turbulence code GS2 was used to calculate critical temperature gradients for the linear, collisionless ion tem- perature gradient (ITG) mode in the National Compact Stellarator Experiment (NCSX) and a prototypical shaped tokamak, based on the pro les of a JET H-mode shot and the stronger shaping of ARIES-AT. While a concern was that the narrow cross section of NCSX at some toroidal locations would result in steep gradients that drive instabilities more easily, it is found that other stabilizing e ects of the stellarator con guration o set this so that the normalized critical gradients for NCSX are competitive with or even better than for the tokamak. For the adiabatic ITG mode, NCSX and the tokamak had similar critical gradients, though beyond marginal stability, NCSX had larger growth rates. However, for the kinetic ITG mode, NCSX had a higher critical gradient and lower growth rates until a/LT ≈#25; …
Date: November 20, 2012
Creator: J.A. Baumgaertel, G.W. Hammett and D.R. Mikkelsen
System: The UNT Digital Library
Award ER25844: Minimizing System Noise Effects for Extreme-Scale Scientific Simulation Through Function Delegation (open access)

Award ER25844: Minimizing System Noise Effects for Extreme-Scale Scientific Simulation Through Function Delegation

In software running on distributed computing clusters, time spent on communication between nodes in the cluster can be a significant portion of the overall computation time; background operating system tasks and other computational �noise� on the nodes of the system can have a significant impact on the amount of time this communication takes, especially on large systems. The research completed in this period has improved understanding of when such noise will have a significant impact. Specifically, it was demonstrated that not just noise on the nodes, but also noise on the network between nodes can have a significant impact on computation time. It was also demonstrated that noise patterns matter more than noise intensity: very regular noise can cause less disruption than lighter (on average) but less regular noise. It was also demonstrated that the effect of noise is more prominent as the speed of the network between nodes is increased. Furthermore, a tracing tool, Netgauge, was improved via our work, and a system simulator, LogGOPSim, was developed; they can be used by application developers to improve performance of their program and by system designers to mitigate the effects of noise by adjusting the noise characteristics of the operating system. …
Date: November 20, 2012
Creator: Lumsdaine, Andrew
System: The UNT Digital Library
Second Line of Defense Spares Program Assessment (open access)

Second Line of Defense Spares Program Assessment

The Office of the Second Line of Defense (SLD) is part of the Department of Energy‘s (DOE) National Nuclear Security Administration (NNSA). The SLD Program accomplishes its critical global security mission by forming cooperative relationships with partner countries to install passive radiation detection systems that augment traditional inspection and law enforcement measures by alerting border officials to the presence of special nuclear or other radiological materials in cross-border traffic. An important tenet of the program is to work collaboratively with these countries to establish the necessary processes, procedures, infrastructure and conditions that will enable them to fully assume the financial and technical responsibilities for operating the equipment. As the number of operational deployments grows, the SLD Program faces an increasingly complex logistics process to promote the timely and efficient supply of spare parts.
Date: November 20, 2012
Creator: Henderson, Dale L.; Muller, George; Mercier, Theresa M.; Brigantic, Robert T.; Perkins, Casey J. & Cooley, Scott K.
System: The UNT Digital Library
Nuclear Data: Progress Report on Sensitivity Analysis at ANL in FY2012. the Trapu Experiment (open access)

Nuclear Data: Progress Report on Sensitivity Analysis at ANL in FY2012. the Trapu Experiment

None
Date: November 20, 2012
Creator: Aliberti, G. (Nuclear Engineering Division)
System: The UNT Digital Library
Final Report for Research Conducted Under MPO B590872 between Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory (open access)
Report on the AMF2 RPY Stabilization Platform: Design and Evaluation (open access)

Report on the AMF2 RPY Stabilization Platform: Design and Evaluation

None
Date: November 20, 2012
Creator: Coulter, R. L.; Martin, T. J. & Orr, B. W.
System: The UNT Digital Library
Generation IV Nuclear Energy System Initiative; Air-Cooled Option Rccs Studies and NSTF Preparation. (open access)

Generation IV Nuclear Energy System Initiative; Air-Cooled Option Rccs Studies and NSTF Preparation.

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Date: November 20, 2012
Creator: Lomperski, S.; Pointer, W.D.; Tzanos, C.P.; Wei, T.Y.C. & Kraus, A.R. (Nuclear Engineering Division)
System: The UNT Digital Library
Second Line of Defense Spares Program (open access)

Second Line of Defense Spares Program

During Fiscal Year 2012, a team from the Pacific Northwest National Laboratory (PNNL) conducted an assessment and analysis of the Second Line of Defense (SLD) Sustainability spare parts program. Spare parts management touches many aspects of the SLD Sustainability Program including contracting and integration of Local Maintenance Providers (LMP), equipment vendors, analyses and metrics on program performance, system state of health, and maintenance practices. Standardized spares management will provide better data for decisions during site transition phase and will facilitate transition to host country sustainability ownership. The effort was coordinated with related SLD Sustainability Program initiatives, including a configuration items baselining initiative, a metrics initiative, and a maintenance initiative. The spares study has also led to pilot programs for sourcing alternatives that include regional intermediate inventories and partnering agreements that leverage existing supply chains. Many partners from the SLD Sustainability program contributed to and were consulted in the course of the study. This document provides a description of the findings, recommendations, and implemented solutions that have resulted from the study.
Date: November 20, 2012
Creator: Henderson, Dale L.; Holmes, Aimee E.; Muller, George; Mercier, Theresa M.; Brigantic, Robert T.; Perkins, Casey J. et al.
System: The UNT Digital Library
Second Line of Defense Master Spares Catalog (open access)

Second Line of Defense Master Spares Catalog

This catalog is intended to be a comprehensive listing of repair parts, components, kits, and consumable items used on the equipment deployed at SLD sites worldwide. The catalog covers detection, CAS, network, ancillary equipment, and tools. The catalog is backed by a Master Parts Database which is used to generate the standard report views of the catalog. The master parts database is a relational database containing a record for every part in the master parts catalog along with supporting tables for normalizing fields in the records. The database also includes supporting queries, database maintenance forms, and reports.
Date: November 20, 2012
Creator: Henderson, Dale L.; Muller, George; Mercier, Theresa M.; Brigantic, Robert T.; Perkins, Casey J. & Cooley, Scott K.
System: The UNT Digital Library