55 Matching Results

Results open in a new window/tab.

Design And Commissioning Status Of New Cylindrical HiPIMS Nb Coating System for SRF Cavities (open access)

Design And Commissioning Status Of New Cylindrical HiPIMS Nb Coating System for SRF Cavities

For the past 19 years Jefferson Lab has sustained a program studying niobium films deposited on small samples in order to develop an understanding of the correlation between deposition parameters, film micro-structure, and RF performance. A new cavity deposition system employing a cylindrical cathode using the HiPIMS technique has been developed to apply this work to cylindrical cavities. The status of this system will be presented.
Date: February 1, 2014
Creator: Phillips, H. Lawrence; Macha, Kurt M. & Valente-Feliciano, Anne-Marie
Object Type: Article
System: The UNT Digital Library
Strategic Energy Analysis (Fact Sheet) (open access)

Strategic Energy Analysis (Fact Sheet)

NREL complements its scientific research with high-quality, credible, technology-neutral, objective analysis that informs policy and investment decisions as renewable energy and energy efficiency technologies move from innovation through integration. This sheet highlights NREL's analytical capabilities and achievements.
Date: February 1, 2014
Creator: unknown
Object Type: Report
System: The UNT Digital Library

[Photograph of Band Members]

Photograph of band members taken at a UNT women's basketball game against the University of Alabama at Birmingham.
Date: February 1, 2014
Creator: Clark, Junebug
Object Type: Photograph
System: The UNT Digital Library

[Photograph of Band Members 2]

Photograph of band members taken at a UNT women's basketball game against the University of Alabama at Birmingham.
Date: February 1, 2014
Creator: Clark, Junebug
Object Type: Photograph
System: The UNT Digital Library

[Photograph of Band Members 3]

Photograph of band members taken at a UNT women's basketball game against the University of Alabama at Birmingham.
Date: February 1, 2014
Creator: Clark, Junebug
Object Type: Photograph
System: The UNT Digital Library
Stratigraphic Profiles for Selected Hanford Site Seismometer Stations and Other Locations (open access)

Stratigraphic Profiles for Selected Hanford Site Seismometer Stations and Other Locations

Stratigraphic profiles were constructed for eight selected Hanford Site seismometer stations, five Hanford Site facility reference locations, and seven regional three-component broadband seismometer stations. These profiles provide interpretations of the subsurface layers to support estimation of ground motions from past earthquakes, and the prediction of ground motions from future earthquakes. In most cases these profiles terminated at the top of the Wanapum Basalt, but at selected sites profiles were extended down to the top of the crystalline basement. The composite one-dimensional stratigraphic profiles were based primarily on previous interpretations from nearby boreholes, and in many cases the nearest deep borehole is located kilometers away.
Date: February 1, 2014
Creator: Last, George V.
Object Type: Report
System: The UNT Digital Library
Global Analysis Of The Negative Parity Non-Strange Baryons In The 1/N{sub c} Expansion (open access)

Global Analysis Of The Negative Parity Non-Strange Baryons In The 1/N{sub c} Expansion

A global study of the negative parity non-strange baryon observables is performed in the framework of the 1/N{sub c} expansion. Masses, partial decay widths and photo-couplings are simultaneously analyzed. A main objective is to determine the composition of the spin 1/2 and 3/2 nucleon states, which come in pairs and involve two mixing angles which can be determined and tested for consistency by the mentioned observables. The issue of the assignment of those nucleon states to the broken SU(4) X O(3) mixed-symmetry multiplet is studied in detail, with the conclusion that the assignment made in the old studies based on the non-relativistic quark model is the preferred one. In addition, the analysis involves an update of the input data with respect to previous works.
Date: February 1, 2014
Creator: Goity, Jose L.; Hampton University, Hampton, VA (United States)]; Gonzalez de Urreta, Emiliano Jose; CONICET, Rivadavia 1917, (1033) Buenos Aires (Argentina)]; Scoccola, Norberto N.; CONICET, Rivadavia 1917, (1033) Buenos Aires (Argentina) et al.
Object Type: Article
System: The UNT Digital Library
ECR Nb Films Grown on Amorphous and Crystalline Cu Substrates: Influence of Ion Energy (open access)

ECR Nb Films Grown on Amorphous and Crystalline Cu Substrates: Influence of Ion Energy

In the pursuit of niobium (Nb) films with similar performance with the commonly used bulk Nb surfaces for Superconducting RF (SRF) applications, significant progress has been made with the development of energetic condensation deposition techniques. Using energetic condensation of ions extracted from plasma generated by Electron Cyclotron Resonance, it has been demonstrated that Nb films with good structural properties and RRR comparable to bulk values can be produced on metallic substrates. The controlled incoming ion energy enables a number of processes such as desorption of adsorbed species, enhanced mobility of surface atoms and sub-implantation of impinging ions, thus producing improved film structures at lower process temperatures. Particular attention is given to the nucleation conditions to create a favourable template for growing the final surface exposed to SRF fields. The influence of the deposition energy on film growth on copper substrates is investigated with the characterization of the film surface, structure, superconducting properties and RF performance.
Date: February 1, 2014
Creator: Valente, Anne-Marie; Eremeev, Grigory V.; Spradlin, Joshua K.; Phillips, H. Lawrence; Reece, Charles E.; Cao, C. et al.
Object Type: Article
System: The UNT Digital Library
Characterization and Fabrication of Spoke Cavities for High-Velocity Applications (open access)

Characterization and Fabrication of Spoke Cavities for High-Velocity Applications

A 500 MHz, velocity-of-light, two-spoke cavity has been designed and optimized for possible use in a compact light source. Here we present the mechanical analysis and steps taken in fabrication of this cavity at Jefferson Lab.
Date: February 1, 2014
Creator: Hopper, Christopher S.; Park, HyeKyoung & Delayen, Jean R.
Object Type: Article
System: The UNT Digital Library
Passive Room-to-Room Air Transfer, Fresno, California (Fact Sheet) (open access)

Passive Room-to-Room Air Transfer, Fresno, California (Fact Sheet)

Field testing was performed in a retrofit unoccupied test house in Fresno, California. Three air-based heating, ventilation, and air conditioning (HVAC) distribution systems - a typical airflow ducted system to the bedrooms, a low airflow ducted system to the bedrooms, and a system with no ductwork to the bedrooms - were evaluated during heating, cooling, and midseason conditions. The relative ability of each of the three systems was assessed with respect to relevant Air Conditioning Contractors of America (ACCA) and ASHRAE standards for house temperature uniformity and stability, respectively. Computational fluid dynamics (CFD) modeling also was performed and refined based on comparison to field test results to determine the air flow rate into the bedrooms of over-door and bottom-of-door air transfer grilles.
Date: February 1, 2014
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Integrated Performance Testing Workshop - Supplemental Materials (Scripts and Procedures) (open access)

Integrated Performance Testing Workshop - Supplemental Materials (Scripts and Procedures)

A variety of performance tests are described relating to: Material Transfers; Emergency Evacuation; Alarm Response Assessment; and an Enhanced Limited Scope Performance Test (ELSPT). Procedures are given for: nuclear material physical inventory and discrepancy; material transfers; and emergency evacuation.
Date: February 1, 2014
Creator: Baum, Gregory A.
Object Type: Text
System: The UNT Digital Library
Development of Nb$_{3}$Sn Cavity Vapor Diffusion Deposition System (open access)

Development of Nb$_{3}$Sn Cavity Vapor Diffusion Deposition System

Nb$_{3}$Sn is a BCS superconductors with the superconducting critical temperature higher than that of niobium, so theoretically it surpasses the limitations of niobium in RF fields. The feasibility of technology has been demonstrated at 1.5 GHz with Nb$_{3}$Sn vapor deposition technique at Wuppertal University$~\cite{Wuppertalthebest}$. The benefit at these frequencies is more pronounced at 4.2 K, where Nb$_{3}$Sn coated cavities show RF resistances an order of magnitude lower than that of niobium. At Jefferson Lab we started the development of Nb$_{3}$Sn vapor diffusion deposition system within an R\&D development program towards compact light sources. Here we present the current progress of the system development.
Date: February 1, 2014
Creator: Eremeev, Grigory V.; Macha, Kurt M.; Clemens, William A.; Park, HyeKyoung & Williams, R. Scott
Object Type: Article
System: The UNT Digital Library
Cascade Apartments - Deep Energy Multifamily Retrofit , Kent, Washington (Fact Sheet) (open access)

Cascade Apartments - Deep Energy Multifamily Retrofit , Kent, Washington (Fact Sheet)

In December of 2009-10, King County Housing Authority (KCHA) implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington (marine climate.)This research effort involved significant coordination from stakeholders KCHA, WA State Department of Commerce, utility Puget Sound Energy, and Cascade tenants. This report focuses on the following three primary BA research questions : 1. What are the modeled energy savings using DOE low income weatherization approved TREAT software? 2. How did the modeled energy savings compare with measured energy savings from aggregate utility billing analysis? 3. What is the Savings to Investment Ratio (SIR) of the retrofit package after considering utility window incentives and KCHA capitol improvement funding.
Date: February 1, 2014
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Final Report for Phase II Study: Prototyping the Sketch Planning Visualization Tool for Non-Motorized Travel (open access)

Final Report for Phase II Study: Prototyping the Sketch Planning Visualization Tool for Non-Motorized Travel

None
Date: February 1, 2014
Creator: Hwang, Ho-Ling; Wilson, Daniel W; Reuscher, Tim; Chin, Shih-Miao & Taylor, Rob D
Object Type: Report
System: The UNT Digital Library
Eastern Renewable Generation Integration Study (Fact Sheet) (open access)

Eastern Renewable Generation Integration Study (Fact Sheet)

This one-page, two-sided fact sheet provides an overview of the Eastern Renewable Generation and Integration Study process.
Date: February 1, 2014
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Tables for Trials and Failures with PD for Designated Confidence Level (open access)

Tables for Trials and Failures with PD for Designated Confidence Level

Two attachments are provided for performance testing of sensors and other Physical Protection System (PPS) components.#2; The first attachment is a table of Trials and Failures, giving Probability of Detection (PD) for a designated confidence level and sorted by trials.#2; The second attachment contains the same data, sorted by failures.
Date: February 1, 2014
Creator: Leach, Janice
Object Type: Text
System: The UNT Digital Library
Idaho National Laboratory Site Environmental Monitoring Plan (open access)

Idaho National Laboratory Site Environmental Monitoring Plan

This plan provides a high-level summary of environmental monitoring performed by various organizations within and around the Idaho National Laboratory (INL) Site as required by U.S. Department of Energy (DOE) Order 435.1, Radioactive Waste Management, and DOE Order 458.1, Radiation Protection of the Public and the Environment, Guide DOE/EH-0173T, Environmental Regulatory Guide for Radiological Effluent Monitoring and Environmental Surveillance, and in accordance with 40 Code of Federal Regulations (CFR) 61, National Emission Standards for Hazardous Air Pollutants. The purpose of these orders is to 1) implement sound stewardship practices that protect the air, water, land, and other natural and cultural resources that may be impacted by DOE operations, and 2) to establish standards and requirements for the operations of DOE and DOE contractors with respect to protection of the environment and members of the public against undue risk from radiation. This plan describes the organizations responsible for conducting environmental monitoring across the INL Site, the rationale for monitoring, the types of media being monitored, where the monitoring is conducted, and where monitoring results can be obtained. Detailed monitoring procedures, program plans, or other governing documents used by contractors or agencies to implement requirements are referenced in this plan. This plan …
Date: February 1, 2014
Creator: Nordstrom, Jenifer
Object Type: Report
System: The UNT Digital Library
A New First-Principles Calculation of Field-Dependent RF Surface Impedance of BCS Superconductor (open access)

A New First-Principles Calculation of Field-Dependent RF Surface Impedance of BCS Superconductor

There is a need to understand the intrinsic limit of radiofrequency (RF) surface impedance that determines the performance of superconducting RF cavities in particle accelerators. Here we present a field-dependent derivation of Mattis-Bardeen theory of the RF surface impedance of BCS superconductors based on the shifted density of states resulting from coherently moving Cooper pairs. Our theoretical prediction of the effective BCS RF surface resistance (Rs) of niobium as a function of peak surface magnetic field amplitude agrees well with recently reported record low loss resonant cavity measurements from JLab and FNAL with carefully, yet differently, prepared niobium material. The surprising reduction in resistance with increasing field is explained to be an intrinsic effect.
Date: February 1, 2014
Creator: Xiao, Binping & Reece, Charles E.
Object Type: Article
System: The UNT Digital Library
Characterization Of Superconducting Samples With SIC System For Thin Film Developments: Status And Recent Results (open access)

Characterization Of Superconducting Samples With SIC System For Thin Film Developments: Status And Recent Results

Within any thin film development program directed towards SRF accelerating structures, there is a need for an RF characterization device that can provide information about RF properties of small samples. The current installation of the RF characterization device at Jefferson Lab is Surface Impedance Characterization (SIC) system. The data acquisition environment for the system has recently been improved to allow for automated measurement, and the system has been routinely used for characterization of bulk Nb, films of Nb on Cu, MgB$_{2}$, NbTiN, Nb$_{3}$Sn films, etc. We present some of the recent results that illustrate present capabilities and limitations of the system.
Date: February 1, 2014
Creator: Phillips, H. Lawrence; Reece, Charles E.; Valente-Feliciano, Anne-Marie; Xiao, Binping & Eremeev, Grigory V.
Object Type: Article
System: The UNT Digital Library
NREL: A Year in Clean Energy Innovations, A Review of NREL's 2013 Feature Stories (Book) (open access)

NREL: A Year in Clean Energy Innovations, A Review of NREL's 2013 Feature Stories (Book)

The publication is a compilation of various feature stories published on NREL's public website, nrel.gov, throughout Calendar Year 2013.
Date: February 1, 2014
Creator: unknown
Object Type: Book
System: The UNT Digital Library
Hall A Annual Report 2013 (open access)

Hall A Annual Report 2013

Report over the experimental activities in Hall A at Thomas Jefferson National Accelerator Facility during 2013.
Date: February 1, 2014
Creator: Dalton, Mark M.
Object Type: Text
System: The UNT Digital Library
Advanced Fuels Campaign Light Water Reactor Accident Tolerant Fuel Performance Metrics Executive Summary (open access)

Advanced Fuels Campaign Light Water Reactor Accident Tolerant Fuel Performance Metrics Executive Summary

Research and development (R&D) activities on advanced, higher performance Light Water Reactor (LWR) fuels have been ongoing for the last few years. Following the unfortunate March 2011 events at the Fukushima Nuclear Power Plant in Japan, the R&D shifted toward enhancing the accident tolerance of LWRs. Qualitative attributes for fuels with enhanced accident tolerance, such as improved reaction kinetics with steam resulting in slower hydrogen generation rate, provide guidance for the design and development of fuels and cladding with enhanced accident tolerance. A common set of technical metrics should be established to aid in the optimization and down selection of candidate designs on a more quantitative basis. “Metrics” describe a set of technical bases by which multiple concepts can be fairly evaluated against a common baseline and against one another. This report describes a proposed technical evaluation methodology that can be applied to evaluate the ability of each concept to meet performance and safety goals relative to the current UO2 – zirconium alloy system and relative to one another. The resultant ranked evaluation can then inform concept down-selection, such that the most promising accident tolerant fuel design option(s) can continue to be developed toward qualification.
Date: February 1, 2014
Creator: Bragg-Sitton, Shannon
Object Type: Report
System: The UNT Digital Library
Comparative Simulation Studies of Multipacting in Higher-Order-Mode Couplers of Superconducting RF Cavities (open access)

Comparative Simulation Studies of Multipacting in Higher-Order-Mode Couplers of Superconducting RF Cavities

Multipacting (MP) in higher-order-mode (HOM) couplers of the International Linear Collider (ILC) baseline cavity and the Continuous Electron Beam Accelerator Facility (CEBAF) 12 GeV upgrade cavity is studied by using the ACE3P suites, developed by the Advanced Computations Department at SLAC. For the ILC cavity HOM coupler, the simulation results show that resonant trajectories exist in three zones, corresponding to an accelerating gradient range of 0.6–1.6 MV/m, 21–34 MV/m, 32–35 MV/m, and > 40MV/m, respectively. For the CEBAF 12 GeV upgrade cavity HOM coupler, resonant trajectories exist in one zone, corresponding to an accelerating gradient range of 6–13 MV/m. Potential implications of these MP barriers are discussed in the context of future high energy pulsed as well as medium energy continuous wave (CW) accelerators based on superconducting radio frequency cavities. Frequency scaling of MP’s predicted in HOM couplers of the ILC, CBEAF upgrade, SNS and FLASH third harmonic cavity is given and found to be in good agreement with the analytical result based on the parallel plate model.
Date: February 1, 2014
Creator: Li, Y. M.; Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)]; Liu, Kexin & Geng, Rongli
Object Type: Article
System: The UNT Digital Library
CEBAF Upgrade: Cryomodule Performance And Lessons Learned (open access)

CEBAF Upgrade: Cryomodule Performance And Lessons Learned

The Thomas Jefferson National Accelerator Facility is currently engaged in the 12 GeV Upgrade Project. The goal of the 12 GeV Upgrade is a doubling of the available beam energy of the Continuous Electron Beam Accelerator Facility (CEBAF) from 6 GeV to 12 GeV. This increase in beam energy will be due in large part to the addition of ten C100 cryomodules plus associated new RF in the CEBAF linacs. The C100 cryomodules are designed to deliver 100 MeV per installed cryomodule. Each C100 cryomodule is built around a string of eight seven-cell, electro-polished, superconducting RF cavities. While an average performance of 100MV per cryomodule is needed to achieve the overall 12 GeV beam energy goal, the actual performance goal for the cryomodules is an average energy gain of 108 MV to provide operational headroom. Cryomodule production started in December 2010. All ten of the C100 cryomodules are installed in the linac tunnels and are on schedule to complete commissioning by September 2013. Performance during Commissioning has ranged from 104 MV to 118 MV. In May, 2012 a test of an early C100 achieved 108 MV with full beam loading. This paper will discuss the performance of the C100 cryomodules …
Date: February 1, 2014
Creator: Drury, Michael A.; Davis, G. Kirk; Hogan, John P.; Hovater, J. Curt; king@jlab.org, Lawrence; Marhauser, Frank et al.
Object Type: Article
System: The UNT Digital Library