National Library of Energy BETA

Sample records for lifetime low-e double-pane

  1. Evaluation of Low-E Storm Windows in the PNNL Lab Homes

    SciTech Connect (OSTI)

    Knox, Jake R.; Widder, Sarah H.

    2014-05-31

    This study examines the performance of exterior and interior low-e storm panels with a controlled whole home experimental design using PNNL's Lab Homes. Summing the estimated annual average heating and cooling savings, the installation of low-e storm panels resulted in approximately 10% annual energy savings. The results of the experiment will be used to determine and validate performance of low-e storm windows over double pane clear glass windows in a whole home setting.

  2. Building America's Low-e Storm Window Adoption Program Plan (FY2014)

    SciTech Connect (OSTI)

    Cort, Katherine A.

    2013-12-23

    Low emissivity (low-e) storm windows/panels appear to hold promise for effectively reducing existing home heating, ventilation, and air-conditioning (HVAC) consumption. Due to the affordability of low-e storm windows and the large numbers of existing homes that have low-performing single-pane or double-pane clear windows, a tremendous opportunity exists to provide energy savings by transforming the low-e storm window market and increasing market adoption. This report outlines U.S. Department of Energy (DOE) Building America’s planned market transformation activities in support of low-e storm window adoption during fiscal year (FY) 2014.

  3. Low-E Retrofit Demonstration and Educational Program

    SciTech Connect (OSTI)

    Culp, Thomas D; Wiehagen, Joseph; Drumheller, S Craig; Siegel, John; Stratmoen, Todd

    2013-11-16

    better than the other. COMMERCIAL CASE STUDIES: (a) A 12-story office building in Philadelphia was retrofitted by adding a double-pane low-E insulating glass unit to the existing single pane windows, to create a triple glazed low-E system. A detailed side-by-side comparison in two pairs of perimeter offices facing north and east showed a 39-60% reduction in heating energy use, a 9-36% reduction in cooling energy use, and a 10% reduction in peak electrical cooling demand. An analysis of utility bills estimated the whole building heating and cooling energy use was reduced by over 25%. Additionally, the retrofit window temperatures were commonly 20 degrees warmer on winter days, and 10-20 degrees cooler on summer days, leading to increased occupant comfort. (b) Two large 4-story office buildings in New Jersey were retrofitted with a similar system, but using two low-E coatings in the retrofit system. The energy savings are being monitored by a separate GPIC project; this work quantified the changes in glass surface temperatures, thermal comfort, and potential glass thermal stress. The low-E retrofit panels greatly reduced daily variations in the interior window surface temperatures, lowering the maximum temperature and raising the minimum temperature by over 20F compared to the original single pane windows with window film. The number of hours of potential thermal discomfort, as measured by deviation between mean radiant temperature and ambient air temperature by more than 3F, were reduced by 93 percent on the south orientation and over two-thirds on the west orientation. Overall, the low-E retrofit led to substantially improved occupant comfort with less periods of both overheating and feeling cold. (c) No significant thermal stress was observed in the New Jersey office building test window when using the low-E retrofit system over a variety of weather conditions. The surface temperature difference only exceeded 10F (500 psi thermal stress) for less than 1.5% of the

  4. Interior and Exterior Low-E Storm Window Installation

    SciTech Connect (OSTI)

    Witters, Sarah

    2014-09-03

    Until recently, energy-efficient window retrofit options have largely been limited to repair or replacement; leaving the homeowner to decide between affordability and deeper energy savings. A new and improved low-e storm window boasts a combination of curb appeal and energy efficiency, all for a fraction of the cost of window replacement. A recent whole-home experiment performed by PNNL suggests that attaching low-e storm windows can result in as much energy savings replacing the windows.

  5. Lifetime and Reliability

    Broader source: Energy.gov [DOE]

    A DOE Solid-State Lighting Program technology fact sheet on lifetime, reliability, and failure as related to LED-based products.

  6. Lifetime and Reliability

    SciTech Connect (OSTI)

    2013-08-01

    Solid-state lighting program technology fact sheet that discusses failure, lifetime, and reliability as they relate to LED-based products.

  7. EERE Success Story-Performance Validation of Low-e Storm Windows...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Validation of Low-e Storm Windows Paves Way for Market Acceptance EERE Success Story-Performance Validation of Low-e Storm Windows Paves Way for Market Acceptance September 30, ...

  8. Performance Validation of Low-e Storm Windows Paves Way for Market Acceptance

    Broader source: Energy.gov [DOE]

    One recent addition to the arsenal of cost-effective efficiency measures is low-emissivity (low-e) storm windows. A low-e coating or glazing is a thin layer deposited directly on the surface of one...

  9. Buildings Energy Data Book: 9.4 High Performance Buildings

    Buildings Energy Data Book [EERE]

    5 Case Study, The Thermal Test Facility, National Renewable Energy Laboratory, Golden, Colorado (Office/Laboratory) Building Design Floor Area: 10,000 SF Floors(1): 2 Aspect Ratio: 1.75 Offices Laboratories Conference Room Mechanical Level Shell Windows Material U-factor SHGC(2) Viewing Windows: Double Pane, Grey Tint, Low-e 0.42 0.44 Clerestory Windows: Double Pane, Clear, Low-e 0.45 0.65 Window Area(SF) North 38 South(3) 1,134 East 56 West 56 Wall/Roof Material Effective R-Value North Wall

  10. R-5 Highly-Insulating Windows and Low-e Storm Windows Volume Purchase Program

    SciTech Connect (OSTI)

    2009-09-30

    Introduces DOE's Building Technologies fenestration RD&D program, and describes the highly insulated R-5 Windows and Low-e Storm Windows Volume Purchase solicitation.

  11. Evaluation of Interior Low-E Storm Windows in the PNNL Lab Homes...

    Office of Scientific and Technical Information (OSTI)

    Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION Lab Homes; Storm; Windows; Low-e; ...

  12. Low-E Storms: The Next "Big Thing" in Window Retrofits

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    America Low-E Storms: The Next "Big Thing" in Window ... compliance with residential and commercial national ... information about window coverings: http:...

  13. Text-Alternative Version of Building America Webinar: Low-e Storms...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Low-e Storms: The Next "Big Thing" in Window Retrofits ... to show compliance for residential and commercial buildings. ... Also there is information on the efficient window coverings ...

  14. Buildings Energy Data Book: 9.4 High Performance Buildings

    Buildings Energy Data Book [EERE]

    3 Case Study, The Visitor Center at Zion National Park, Utah (Service/Retail/Office) Building Design Vistors Center (1): 8,800 SF Comfort Station (2): 2,756 SF Fee Station: 170 SF Shell Windows Type U-Factor SHGC (3) South/East Glass Double Pane Insulating Glass, Low-e, Aluminum Frames, Thermally Broken 0.44 0.44 North/West Glass Double Pane Insulating Glass, Heat Mirror, Aluminum Frames, Thermally Broken 0.37 0.37 Window/Wall Ratio: 28% Wall/Roof Materials Effective R-Value Trombe Walls:

  15. 'Thirsty' Metals Key to Longer Battery Lifetimes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    'Thirsty' Metals Key to Longer Battery Lifetimes 'Thirsty' Metals Key to Longer Battery Lifetimes Computations at NERSC show how multiply charged metal ions impact battery capacity ...

  16. Storm Windows (Even with a Low-E Coating!) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Storm Windows (Even with a Low-E Coating) November 11, 2008 - 3:45pm Addthis John Lippert ... Alex is one of the world's experts on green building materials, so I'm always glad to see ...

  17. Building America Webinar: Low-E Storms: The Next Big Thing in...

    Energy Savers [EERE]

    This Building America webinar presented a new and improved low-e storm window that boasts a combination of curb appeal and energy efficiency, all for a fraction of the cost of ...

  18. Low-e Storm Windows: Market Assessment and Pathways to Market Transformation

    SciTech Connect (OSTI)

    Cort, Katherine A.

    2013-06-08

    Field studies sponsored by the U.S. Department of Energy (DOE) have shown that the use of low-e storm windows can lead to significant heating and cooling energy savings in residential homes. This study examines the market for low-e storm windows based on market data, case studies, and recent experience with weatherization deployment programs. It uses information from interviews conducted with DOE researchers and industry partners involved in case studies and early deployment efforts related to low-e storm windows. In addition, this study examines potential barriers to market acceptance, assesses the market and energy savings potential, and identifies opportunities to transform the market for low-e storm windows and overcome market adoption barriers.

  19. Building America Webinar: Low-E Storms: The Next Big Thing in Window Retrofits

    Office of Energy Efficiency and Renewable Energy (EERE)

    This Building America webinar presented a new and improved low-e storm window that boasts a combination of curb appeal and energy efficiency, all for a fraction of the cost of window replacement, on Sept. 9, 2014.

  20. EERE Success Story—Performance Validation of Low-e Storm Windows Paves Way for Market Acceptance

    Broader source: Energy.gov [DOE]

    One recent addition to the arsenal of cost-effective efficiency measures is low-emissivity (low-e) storm windows. A low-e coating or glazing is a thin layer deposited directly on the surface of one...

  1. Building America Webinar: High Performance Enclosure Strategies, Part II: Low-E Storm Windows and Window Attachments

    Office of Energy Efficiency and Renewable Energy (EERE)

    Presentation from Building America Webinar: High Performance Enclosure Strategies, Part II: Low-E Storm Windows and Window Attachments.

  2. Energy Savings of Low-E Storm Windows and Panels across US Climate Zones

    SciTech Connect (OSTI)

    Culp, Thomas D.; Cort, Katherine A.

    2015-10-01

    This report builds off of previous modeling work related to low-e storm windows used to create a "Database of U.S. Climate-Based Analysis for Low-E Storm Windows." This work updates similar studies using new fuel costs and examining the separate contributions of reduced air leakage and reduced coefficients of overall heat transfer and solar heat gain. In this report we examine the energy savings and cost effectiveness of low-E storm windows in residential homes across a broad range of U.S. climates, excluding the impact from infiltration reductions, which tend to vary using the National Energy Audit Tool (NEAT) and RESFEN model calculations. This report includes a summary of the results, NEAT and RESFEN background, methodology, and input assumptions, and an appendix with detailed results and assumptions by climate zone.

  3. Thermal and Optical Properties of Low-E Storm Windows and Panels

    SciTech Connect (OSTI)

    Culp, Thomas D.; Widder, Sarah H.; Cort, Katherine A.

    2015-07-17

    Installing low-emissivity (low-E) storm windows and panels over existing windows has been identified as a cost-effective new approach for improving the energy efficiency of existing buildings where window replacement is impractical or too expensive. As such, it is desirable to characterize the key energy performance properties of low-E storm windows and panels when installed over different types of existing primary windows. this paper presents the representative U-factors, solar heat gain coefficients (SGHCs) and visible transmittance properties of the combined assemblies of various storm windows and panel types installed over different primary windows.

  4. Database of Low-e Storm Window Energy Performance across U.S. Climate Zones

    SciTech Connect (OSTI)

    Culp, Thomas D.; Cort, Katherine A.

    2014-09-04

    This is an update of a report that describes process, assumptions, and modeling results produced Create a Database of U.S. Climate-Based Analysis for Low-E Storm Windows. The scope of the overall effort is to develop a database of energy savings and cost effectiveness of low-E storm windows in residential homes across a broad range of U.S. climates using the National Energy Audit Tool (NEAT) and RESFEN model calculations. This report includes a summary of the results, NEAT and RESFEN background, methodology, and input assumptions, and an appendix with detailed results and assumptions by cliamte zone.

  5. Low-Cost, Highly Transparent Flexible low-e Coating Film to Enable Electrochromic Windows with Increased Energy Savings

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Berland, bberland@itnes.com ITN Energy Systems Low-Cost, Highly Transparent Flexible low-e Coating Film to Enable Electrochromic Windows with Increased Energy Savings 2014 Building Technologies Office Peer Review 2 Project Summary Timeline: Start date: October 1, 2013 Planned end date: September 30, 2014 Key Milestones 1.Low-e Film: 90% T,vis & R,ir (100 cm 2 ) (Q2) 2.Low-e Film: 90% T,vis & R,ir (2m long, %T,%R variation < 2% cross web) (Q3) 3.Demonstrate Low-e/EC Film (Q3) Budget:

  6. Text-Alternative Version of Building America Webinar: Low-e Storms: The Next "Big Thing" in Window Retrofits

    Broader source: Energy.gov [DOE]

    Low-e Storms:  The Next “Big Thing” in Window RetrofitsOfficial Webinar Transcript (September 9, 2014)

  7. Low-cost, highly transparent flexible low-e coating film to enable electrochromic windows with increased energy savings

    SciTech Connect (OSTI)

    Berland, Brian; Hollingsworth, Russell

    2015-03-31

    Five Quads of energy are lost through windows annually in the U.S. Low-e coatings are increasingly employed to reduce the wasted energy. Most commonly, the low-e coating is an oxide material applied directly to the glass at high temperature. With over 100,000,000 existing homes, a retrofit product is crucial to achieve widespread energy savings. Low-e films, i.e. coatings on polymeric substrates, are now also available to meet this need. However, the traditional oxide materials and process is incompatible with low temperature plastics. Alternate high performing low-e films typically incorporate materials that limit visible transmission to 35% or less. Further, the cost is high. The objective of this award was to develop a retrofit, integrated low-e/electrochromic window film to dramatically reduce energy lost through windows. While field testing of state-of-the-art electrochromic (EC) windows show the energy savings are maximized if a low-e coating is used in conjunction with the EC, available low-e films have a low visible transmission (~70% or less) that limits the achievable clear state and therefore, appearance and energy savings potential. Comprehensive energy savings models were completed at Lawrence Berkeley National Lab (LBNL). A parametric approach was used to project energy usage for windows with a large range of low-e properties across all U.S. climate zones, without limiting the study to materials that had already been produced commercially or made in a lab. The model enables projection of energy savings for low-e films as well as integrated low-e/EC products. This project developed a novel low-e film, optimized for compatibility with EC windows, using low temperature, high deposition rate processes for the growth of low-e coatings on plastic films by microwave plasma enhanced chemical vapor deposition. Silica films with good density and optical properties were demonstrated at deposition rates as high as 130Å/sec. A simple bi-layer low-e stack of

  8. Models for Battery Reliability and Lifetime

    SciTech Connect (OSTI)

    Smith, K.; Wood, E.; Santhanagopalan, S.; Kim, G. H.; Neubauer, J.; Pesaran, A.

    2014-03-01

    Models describing battery degradation physics are needed to more accurately understand how battery usage and next-generation battery designs can be optimized for performance and lifetime. Such lifetime models may also reduce the cost of battery aging experiments and shorten the time required to validate battery lifetime. Models for chemical degradation and mechanical stress are reviewed. Experimental analysis of aging data from a commercial iron-phosphate lithium-ion (Li-ion) cell elucidates the relative importance of several mechanical stress-induced degradation mechanisms.

  9. LED Luminaire Lifetime: Recommendations For Testing and Reporting |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Luminaire Lifetime: Recommendations For Testing and Reporting LED Luminaire Lifetime: Recommendations For Testing and Reporting LED Luminaire Lifetime: September 2014 (774.47 KB) More Documents & Publications System Reliability Model for Solid-State Lighting Luminaires LED LUMINAIRE LIFETIME: Recommendations for Testing and Reporting Lifetime and Reliability

  10. Development of fluorescence lifetime diagnostic. Project accomplishments

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    summary (Attachment 1), Revision 1 (Technical Report) | SciTech Connect Technical Report: Development of fluorescence lifetime diagnostic. Project accomplishments summary (Attachment 1), Revision 1 Citation Details In-Document Search Title: Development of fluorescence lifetime diagnostic. Project accomplishments summary (Attachment 1), Revision 1 × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and

  11. NREL Engineer Gets Lifetime Achievement Award

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Engineer Gets Lifetime Achievement Award For more information contact: e:mail: Public Affairs Golden, Colo., May 20, 1998 — A senior engineer at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) will receive a major international award for his career-long contributions to the design of energy efficient buildings. Douglas Balcomb has been selected to receive the 1998 Lifetime Achievement Award from the Passive and Low-Energy Architecture (PLEA) network at the group's

  12. 'Thirsty' Metals Key to Longer Battery Lifetimes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    'Thirsty' Metals Key to Longer Battery Lifetimes 'Thirsty' Metals Key to Longer Battery Lifetimes Computations at NERSC show how multiply charged metal ions impact battery capacity June 30, 2014 Contact: Kathy Kincade, +1 510 495 2124, kkincade@lbl.gov PCCPxantheascover Imagine a cell phone battery that lasted a whole week on a single charge. A car battery that worked for months between charges. A massive battery that stores the intermittent electricity from wind turbines and releases it when

  13. Polymer Electrolyte Fuel Cell Lifetime Limitations: The Role...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Electrolyte Fuel Cell Lifetime Limitations: The Role of Electrocatalyst Degradation Polymer Electrolyte Fuel Cell Lifetime Limitations: The Role of Electrocatalyst Degradation ...

  14. Measuring and modeling the lifetime of nitrous oxide including...

    Office of Scientific and Technical Information (OSTI)

    Published Article: Measuring and modeling the lifetime of nitrous oxide including its variability: NITROUS OXIDE AND ITS CHANGING LIFETIME Prev Next Title: Measuring and ...

  15. Final Report - Three-dimensional minority carrier lifetime mapping...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Three-dimensional minority carrier lifetime mapping of thin film semiconductors for solar cell applications Final Report - Three-dimensional minority carrier lifetime mapping of ...

  16. Statistical and Domain Analytics Applied to PV Module Lifetime...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Statistical and Domain Analytics Applied to PV Module Lifetime and Degradation Science Statistical and Domain Analytics Applied to PV Module Lifetime and Degradation Science ...

  17. Prompt Neutron Lifetime for the NBSR Reactor

    SciTech Connect (OSTI)

    Hanson, A.L.; Diamond, D.

    2012-06-24

    In preparation for the proposed conversion of the National Institute of Standards and Technology (NIST) research reactor (NBSR) from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel, certain point kinetics parameters must be calculated. We report here values of the prompt neutron lifetime that have been calculated using three independent methods. All three sets of calculations demonstrate that the prompt neutron lifetime is shorter for the LEU fuel when compared to the HEU fuel and longer for the equilibrium end-of-cycle (EOC) condition when compared to the equilibrium startup (SU) condition for both the HEU and LEU fuels.

  18. An approach for longer lifetime MCFCs

    SciTech Connect (OSTI)

    Matsumoto, Masaru; Tatsumi, Masahiko; Hayano, Takuro

    1996-12-31

    For entering into commercialization of MCFC power plants in the beginning of the 21st century, we will devote to research for increasing lifetime as long as 40,000 hours with cell performance decay rate of 0.25 %/1000hrs as the target in FY 1999. This paper will discuss on our approach for longer lifetime MCFCs through electrolyte-loss management and NiO precipitation management as well as micro-structural control of electrodes and matrix plates. Cell voltage decay rate will be estimated by simulation through series of experiments on accelerated conditions.

  19. Measurement of the Omega0(c) lifetime

    SciTech Connect (OSTI)

    Iori, M.; Ayan, A.S.; Akgun, U.; Alkhazov, G.; Amaro-Reyes, J.; Atamantchouk, A.G.; Balatz, M.Y.; Blanco-Covarrubias, A.; Bondar, N.F.; Cooper, P.S.; Dauwe, L.J.; /Ball State U. /Bogazici U. /Carnegie Mellon U. /Rio de Janeiro, CBPF /Fermilab /Serpukhov, IHEP /Beijing, Inst. High Energy Phys. /Moscow, ITEP /Heidelberg, Max Planck Inst. /Moscow State U. /St. Petersburg, INP

    2007-01-01

    The authors report a precise measurement of the {Omega}{sub c}{sup 0} lifetime. The data were taken by the SELEX (E781) experiment using 600 GeV/c {Sigma}{sup -}, {pi}{sup -} and p beams. The measurement has been made using 83 {+-} 19 reconstructed {Omega}{sub c}{sup 0} in the {Omega}{sup -} {pi}{sup -}{pi}{sup +}{pi}{sup +} and {Omega}{sup -} {pi}{sup +} decay modes. The lifetime of the {Omega}{sub c}{sup 0} is measured to be 65 {+-} 13(stat) {+-} 9(sys) fs.

  20. Overview of Field Experience - Degradation Rates & Lifetimes

    SciTech Connect (OSTI)

    Jordan, Dirk; Kurtz, Sarah

    2015-09-14

    The way a PV module fails may depend not only on its design and the materials used in its construction, but also on the weather it experiences, the way it is mounted, and the quality control during its manufacture. This presentation gives an overview of Field Experience - what degradation rates and what lifetimes are being observed in various regions.

  1. Neutrinos and cosmology: a lifetime relationship

    SciTech Connect (OSTI)

    Serpico, Pasquale D.; /Fermilab

    2008-06-01

    We consider the example of neutrino decays to illustrate the profound relation between laboratory neutrino physics and cosmology. Two case studies are presented: In the first one, we show how the high precision cosmic microwave background spectral data collected by the FIRAS instrument on board of COBE, when combined with Lab data, have greatly changed bounds on the radiative neutrino lifetime. In the second case, we speculate on the consequence for neutrino physics of the cosmological detection of neutrino masses even as small as {approx}0.06 eV, the lower limit guaranteed by neutrino oscillation experiments. We show that a detection at that level would improve by many orders of magnitude the existing limits on neutrino lifetime, and as a consequence on some models of neutrino secret interactions.

  2. Quasiparticle inelastic lifetimes in disordered superconducting films

    SciTech Connect (OSTI)

    Devereaux, T.P.; Belitz, D. )

    1991-09-01

    We present a comprehensive theory of quasiparticle inelastic lifetimes close to equilibrium in disordered superconducting films. The lifetime due to Coulomb interactions in two-dimensional (2D) films is calculated in analogy to a recent 3D calculation. For the phonon contribution, we extend the results of Reizer and Sergeyev for clean 3D systems to 2D, and determine the leading disorder renormalization. We then construct an interpolation formula for films of finite thickness that correctly reproduces the 2D and 3D limits. We give a general discussion of our results, and compare them with experiments. Agreement with measurements on thick films is good, while in the 2D limit nonequilibrium effects are likely to play an important role.

  3. $B$ mixing and lifetimes at the Tevatron

    SciTech Connect (OSTI)

    Gomez-Ceballos, G.; Piedra, J.

    2006-04-01

    The Tevatron collider at Fermilab provides a very rich environment for the study of b-hadrons. Both the D0 and CDF experiments have collected a sample of about 1 fb{sup -1}. they report results on three topics: b-hadron lifetimes, polarization amplitudes and the decay width difference in B{sub s}{sup 0} {yields} J/{psi}{phi}, and B{sub s}{sup 0} mixing.

  4. Photodriving Water Oxidation Catalysts: Extending Hole Lifetimes | ANSER

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Center | Argonne-Northwestern National Laboratory Photodriving Water Oxidation Catalysts: Extending Hole Lifetimes Home > Research > ANSER Research Highlights > Photodriving Water Oxidation Catalysts: Extending Hole Lifetimes

  5. NREL: Measurements and Characterization - Minority-Carrier Lifetime...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Photoluminescence Spectroscopy Minority-Carrier Lifetime Spectroscopy Fourier-Transform Infrared & Raman Spectroscopy Spectroscopic Ellipsometry Capacitance Techniques Scanning ...

  6. Text-Alternative Version of Building America Webinar: High Performance Enclosure Strategies, Part II: Low-E Storm Windows and Window Attachments

    Broader source: Energy.gov [DOE]

    Text-Alternative Version of Building America Webinar: High Performance Enclosure Strategies, Part II: Low-E Storm Windows and Window Attachments

  7. Final report on reliability and lifetime prediction.

    SciTech Connect (OSTI)

    Gillen, Kenneth Todd; Wise, Jonathan; Jones, Gary D.; Causa, Al G.; Terrill, Edward R.; Borowczak, Marc

    2012-12-01

    This document highlights the important results obtained from the subtask of the Goodyear CRADA devoted to better understanding reliability of tires and to developing better lifetime prediction methods. The overall objective was to establish the chemical and physical basis for the degradation of tires using standard as well as unique models and experimental techniques. Of particular interest was the potential application of our unique modulus profiling apparatus for assessing tire properties and for following tire degradation. During the course of this complex investigation, extensive relevant information was generated, including experimental results, data analyses and development of models and instruments. Detailed descriptions of the findings are included in this report.

  8. Analog detection for cavity lifetime spectroscopy

    DOE Patents [OSTI]

    Zare, Richard N.; Harb, Charles C.; Paldus, Barbara A.; Spence, Thomas G.

    2001-05-15

    An analog detection system for determining a ring-down rate or decay rate 1/.tau. of an exponentially decaying ring-down beam issuing from a lifetime or ring-down cavity during a ring-down phase. Alternatively, the analog detection system determines a build-up rate of an exponentially growing beam issuing from the cavity during a ring-up phase. The analog system can be employed in continuous wave cavity ring-down spectroscopy (CW CRDS) and pulsed CRDS (P CRDS) arrangements utilizing any type of ring-down cavity including ring-cavities and linear cavities.

  9. Analog detection for cavity lifetime spectroscopy

    DOE Patents [OSTI]

    Zare, Richard N.; Harb, Charles C.; Paldus, Barbara A.; Spence, Thomas G.

    2003-01-01

    An analog detection system for determining a ring-down rate or decay rate 1/.tau. of an exponentially decaying ring-down beam issuing from a lifetime or ring-down cavity during a ring-down phase. Alternatively, the analog detection system determines a build-up rate of an exponentially growing beam issuing from the cavity during a ring-up phase. The analog system can be employed in continuous wave cavity ring-down spectroscopy (CW CRDS) and pulsed CRDS (P CRDS) arrangements utilizing any type of ring-down cavity including ring-cavities and linear cavities.

  10. Request for Information for Photovoltaic Lifetime Project

    Broader source: Energy.gov [DOE]

    In return on investment calculations, the degradation and service lifetimes of PV modules are often assumed to be the same across different panels. Due to the typically slow pace of degradation in operating solar modules, often less than 1% (relative) per year, as well as variations in the operating and test conditions, the differences in panel degradation rates are difficult both to measure and compare. Much of the degradation data available to date involves precise measurement of the module performance at only one (end of life) or two (end of life and beginning of life) points in time. If the module’s degradation profile is not linear, a significant miscalculation of levelized cost of energy may result. The purpose of this RFI is to solicit feedback from industry, academia, research laboratories, government agencies, and other stakeholders to identify approaches that would expand the dataset publicly available for service lifetime prediction for PV systems; specifically, data that would better inform calculations of the return on investment of existing and future PV installations.

  11. NREL Launches Partnership with Solarmer Energy to Extend Lifetime of

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Plastic Solar Cells - News Releases | NREL Launches Partnership with Solarmer Energy to Extend Lifetime of Plastic Solar Cells June 21, 2010 The U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) and Solarmer Energy, Inc., have signed a Cooperative Research and Development Agreement (CRADA) to collaborate on improving the lifetime of plastic solar cells, a promising new solar conversion technology. The joint research covered by the CRADA will explore the lifetime

  12. Predictive Models of Li-ion Battery Lifetime (Presentation) Smith...

    Office of Scientific and Technical Information (OSTI)

    Predictive Models of Li-ion Battery Lifetime (Presentation) Smith, K.; Wood, E.; Santhanagopalan, S.; Kim, G.; Shi, Y.; Pesaran, A. 25 ENERGY STORAGE; 33 ADVANCED PROPULSION...

  13. Battery Lifetime Analysis and Simulation Tool (BLAST) Documentation

    Office of Scientific and Technical Information (OSTI)

    Battery Lifetime Analysis and Simulation Tool (BLAST) Documentation Neubauer, J. 25 ENERGY STORAGE BATTERY; LITHIUM-ION; STATIONARY ENERGY STORAGE; BLAST; BATTERY DEGRADATION;...

  14. Finite Lifetime Effects on the Polarizability Within Time-dependent...

    Office of Scientific and Technical Information (OSTI)

    Density-functional Theory Citation Details In-Document Search Title: Finite Lifetime Effects on the Polarizability Within Time-dependent Density-functional Theory The research ...

  15. Predictive Models of Li-ion Battery Lifetime (Presentation) ...

    Office of Scientific and Technical Information (OSTI)

    Opportunities for extending the lifetime of commercial battery systems are explored. Authors: Smith, K. ; Wood, E. ; Santhanagopalan, S. ; Kim, G. ; Shi, Y. ; Pesaran, A. ...

  16. LED LUMINAIRE LIFETIME: Recommendations for Testing and Reporting...

    Energy Savers [EERE]

    More Documents & Publications System Reliability Model for Solid-State Lighting Luminaires LED Luminaire Lifetime: Recommendations For Testing and Reporting System Reliability ...

  17. Lifetime of the phonons in the PLT ceramic

    SciTech Connect (OSTI)

    Barba-Ortega, J. Joya, M. R.; Londoo, F. A.

    2014-11-05

    The lifetimes at higher temperatures on lanthanum-modified lead titanate (PLT) are mainly due to the anharmonic decay of optical phonons into low-energy phonons. The temperature-independent contributions from inherent crystal defects and from boundary scattering become comparable to the phonon scattering contribution at lower temperatures. The thermal interaction is large at higher temperatures which decreases the phonon mean free path, and so the decay lifetime decreases as the temperature of the system is increased. This leads to the increased line width at higher temperatures. We made an estimate of the lifetimes for different concentrations and temperatures in PLT.

  18. Project Profile: Lifetime Model Development for Supercritical CO2 CSP

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Systems (SuNLaMP) | Department of Energy Project Profile: Lifetime Model Development for Supercritical CO2 CSP Systems (SuNLaMP) Project Profile: Lifetime Model Development for Supercritical CO2 CSP Systems (SuNLaMP) Funding Program: SuNLaMP SunShot Subprogram: CSP Location: Oak Ridge National Laboratory, Oak Ridge, TN SunShot Award Amount: $2,175,000 This project seeks to develop a predictive lifetime model for materials in supercritical carbon dioxide (sCO2) conditions similar to

  19. The Lifetime of a beautiful and charming meson: B_c lifetime measured using the D0 detector

    SciTech Connect (OSTI)

    Welty-Rieger, Leah Christine; /Indiana U.

    2008-09-01

    Using approximately 1.3 fb{sup -1} of data collected by the D0 detector between 2002 and 2006, the lifetime of the B{sub c}{sup {+-}} meson is studied in the B{sub c}{sup {+-}} {yields} J/{psi}{mu}{sup {+-}} + X final state. Using an unbinned likelihood simultaneous fit to J/{psi} + {mu} invariant mass and lifetime distributions, a signal of 810 {+-} 80(stat.) candidates is estimated and a lifetime measurement made of: {tau}(B{sub c}{sup {+-}}) = 0.448{sub -0.036}{sup +0.038}(stat) {+-} 0.032(sys) ps.

  20. DC photogun vacuum characterization through photocathode lifetime studies

    SciTech Connect (OSTI)

    Marcy Stutzman; Joseph Grames; Matt Poelker; Kenneth Surles-Law; Philip Adderley

    2007-07-02

    Excellent vacuum is essential for long photocathode lifetimes in DC high voltage photoelectron guns. Vacuum Research at Thomas Jefferson National Accelerator Facility has focused on characterizing the existing vacuum systems at the CEBAF polarized photoinjector and on quantifying improvements for new systems. Vacuum chamber preprocessing, full activation of NEG pumps and NEG coating the chamber walls should improve the vacuum within the electron gun, however, pressure measurement is difficult at pressures approaching the extreme-high-vacuum (XHV) region and extractor gauge readings are not significantly different between the improved and original systems. The ultimate test of vacuum in a DC high voltage photogun is the photocathode lifetime, which is limited by the ionization and back-bombardment of residual gasses. Discussion will include our new load-locked gun design as well as lifetime measurements in both our operational and new photo-guns, and the correlations between measured vacuum and lifetimes will be investigated.

  1. Predictive Models of Li-ion Battery Lifetime

    SciTech Connect (OSTI)

    Smith, Kandler; Wood, Eric; Santhanagopalan, Shriram; Kim, Gi-heon; Shi, Ying; Pesaran, Ahmad

    2015-06-15

    It remains an open question how best to predict real-world battery lifetime based on accelerated calendar and cycle aging data from the laboratory. Multiple degradation mechanisms due to (electro)chemical, thermal, and mechanical coupled phenomena influence Li-ion battery lifetime, each with different dependence on time, cycling and thermal environment. The standardization of life predictive models would benefit the industry by reducing test time and streamlining development of system controls.

  2. Battery Lifetime Analysis and Simulation Tool (BLAST) Documentation

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Battery Lifetime Analysis and Simulation Tool (BLAST) Documentation Citation Details In-Document Search Title: Battery Lifetime Analysis and Simulation Tool (BLAST) Documentation The deployment and use of lithium-ion batteries in automotive and stationary energy storage applications must be optimized to justify their high up-front costs. Given that batteries degrade with use and storage, such optimizations must evaluate many years of operation. As the

  3. Predictive Models of Li-ion Battery Lifetime (Presentation) (Conference) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Predictive Models of Li-ion Battery Lifetime (Presentation) Citation Details In-Document Search Title: Predictive Models of Li-ion Battery Lifetime (Presentation) Predictive models of Li-ion battery reliability must consider a multiplicity of electrochemical, thermal and mechanical degradation modes experienced by batteries in application environments. Complicating matters, Li-ion batteries can experience several path dependent degradation trajectories dependent on storage

  4. High Precision Measurement of the 19Ne Lifetime

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Precision Measurement of the 19 Ne Lifetime by Leah Jacklyn Broussard Department of Physics Duke University Date: Approved: Albert Young Calvin Howell Kate Scholberg Berndt Mueller John Thomas Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Physics in the Graduate School of Duke University 2012 Abstract (Nuclear physics) High Precision Measurement of the 19 Ne Lifetime by Leah Jacklyn Broussard Department of Physics

  5. Statistical and Domain Analytics Applied to PV Module Lifetime and

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Degradation Science | Department of Energy Statistical and Domain Analytics Applied to PV Module Lifetime and Degradation Science Statistical and Domain Analytics Applied to PV Module Lifetime and Degradation Science Presented at the PV Module Reliability Workshop, February 26 - 27 2013, Golden, Colorado pvmrw13_ps2_casewestern_bruckman.pdf (6.77 MB) More Documents & Publications Literature Review of the Effects of UV Exposure on PV Modules Failure Rates from Certification Testing to UL

  6. Key Parameters Affecting DPF Performance Degradation and Impact on Lifetime

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Fuel Economy | Department of Energy Parameters Affecting DPF Performance Degradation and Impact on Lifetime Fuel Economy Key Parameters Affecting DPF Performance Degradation and Impact on Lifetime Fuel Economy Summarizes latest findings on impact of specific parameters affecting ash-related diesel particulate filter performance degradation and information useful to enhance performance and extend service life deer11_sappok.pdf (3.32 MB) More Documents & Publications Characteristics and

  7. Database of Low-E Storm Window Energy Performance across U.S. Climate Zones (Task ET-WIN-PNNL-FY13-01_5.3)

    SciTech Connect (OSTI)

    Cort, Katherine A.; Culp, Thomas D.

    2013-09-01

    This report describes process, assumptions, and modeling results produced in support of the Emerging Technologies Low-e Storm Windows Task 5.3: Create a Database of U.S. Climate-Based Analysis for Low-E Storm Windows. The scope of the overall effort is to develop a database of energy savings and cost effectiveness of low-E storm windows in residential homes across a broad range of U.S. climates using the National Energy Audit Tool (NEAT) and RESFEN model calculations. This report includes a summary of the results, NEAT and RESFEN background, methodology, and input assumptions, and an appendix with detailed results and assumptions by cliamte zone. Both sets of calculation results will be made publicly available through the Building America Solution Center.

  8. Buildings Energy Data Book: 9.4 High Performance Buildings

    Buildings Energy Data Book [EERE]

    4 Case Study, The Philip Merrill Environmental Center, Annapolis, Maryland (Office) Building Design Floor Area: 31,000 SF Floors: 2 Footprint: 220 ft. x (1) 2 Floors of open office space Attached pavilion containing: Meeting space Kitchen Staff dining Conference room Shell Windows U-Factor SHGC (2) Type: Double Pane, Low-e, Argon Filled Insulating Glass 0.244 0.41 Wall/Roof Material Effective R-Value Interior Wall plywood, gypsum, SIP foam, and sheathing 28.0 Exterior Wall gypsum and insulated

  9. Effect of Superalloy Substrate and Bond Coating on TBC Lifetime

    SciTech Connect (OSTI)

    Pint, Bruce A; Haynes, James A; Zhang, Ying

    2010-01-01

    Several different single-crystal superalloys were coated with different bond coatings to study the effect of composition on the cyclic oxidation lifetime of an yttria-stabilized zirconia (YSZ) top coating deposited by electron beam physical vapor deposition from a commercial source. Three different superalloys were coated with a 7 {micro}m Pt layer that was diffused into the surface prior to YSZ deposition. One of the superalloys, N5, was coated with a low activity, Pt-modified aluminide coating and Pt-diffusion coatings with 3 and 7 {micro}m of Pt. Three coatings of each type were furnace cycled to failure in 1 h cycles at 1150 C to assess average coating lifetime. The 7 {micro}m Pt diffusion coating on N5 had an average YSZ coating lifetime >50% higher than a Pt-modified aluminide coating on N5. Without a YSZ coating, the Pt-modified aluminide coating on N5 showed the typical surface deformation during cycling, however, the deformation was greatly reduced when constrained by the YSZ coating. The 3 {micro}m Pt diffusion coating had a similar average lifetime as the Pt-modified aluminide coating but a much wider scatter. The Pt diffusion bond coating on superalloy X4 containing Ti exhibited the shortest YSZ coating lifetime, this alloy-coating combination also showed the worst alumina scale adhesion without a YSZ coating. The third generation superalloy N6 exhibited the longest coating lifetime with a 7 {micro}m Pt diffusion coating.

  10. Radiative lifetimes of metastable states of negative ions

    SciTech Connect (OSTI)

    Andersson, Pontus; Fritioff, Karin; Sandstroem, Joakim; Collins, Gerard; Hanstorp, Dag; Ellmann, Anna; Schef, Peter; Lundin, Peter; Mannervik, Sven; Royen, Peder; Froese Fischer, K. Charlotte; Oesterdahl, Fabian; Rostohar, Danijela; Pegg, David J.; Gibson, N. D.; Danared, Haakan; Kaellberg, Anders

    2006-03-15

    We present a technique for measuring the radiative lifetimes of metastable states of negative ions that involves the use of a heavy-ion storage ring. The method has been applied to investigate the radiative decay of the np{sup 3} {sup 2}P{sub 1/2} levels of Te{sup -}(n=5) and Se{sup -}(n=4) and the 3p{sup 3} {sup 2}D state of Si{sup -} for which the J=3/2 and 5/2 levels were unresolved. All of these states are metastable and decay primarily by emission of E2 and M1 radiation. Multi Configuration Dirac-Hartree-Fock calculations of rates for the transitions in Te{sup -} and Se{sup -} yielded lifetimes of 0.45 s and 4.7 s, respectively. The measured values agree well with these predicted values. In the case of the {sup 2}D state of Si{sup -}, however, our measurement was only able to set a lower limit on the lifetime. The upper limit of the lifetime that can be measured with our apparatus is set by how long the ions can be stored in the ring, a limit determined by the rate of collisional detachment. Our lower limit of 1 min for the lifetime of the {sup 2}D state is consistent with both the calculated lifetimes of 162 s for the {sup 2}D{sub 3/2} level and 27.3 h for the {sup 2}D{sub 5/2} level reported by O'Malley and Beck and 14.5 h and 12.5 h, respectively, from our Breit-Pauli calculations.

  11. Models for Battery Reliability and Lifetime: Applications in Design and Health Management (Presentation)

    SciTech Connect (OSTI)

    Smith, K.; Neubauer, J.; Wood, E.; Jun, M.; Pesaran, A.

    2013-06-01

    This presentation discusses models for battery reliability and lifetime and the Battery Ownership Model.

  12. Apparatus for measuring minority carrier lifetimes in semiconductor materials

    DOE Patents [OSTI]

    Ahrenkiel, Richard K.

    1999-01-01

    An apparatus for determining the minority carrier lifetime of a semiconductor sample includes a positioner for moving the sample relative to a coil. The coil is connected to a bridge circuit such that the impedance of one arm of the bridge circuit is varied as sample is positioned relative to the coil. The sample is positioned relative to the coil such that any change in the photoconductance of the sample created by illumination of the sample creates a linearly related change in the input impedance of the bridge circuit. In addition, the apparatus is calibrated to work at a fixed frequency so that the apparatus maintains a consistently high sensitivity and high linearly for samples of different sizes, shapes, and material properties. When a light source illuminates the sample, the impedance of the bridge circuit is altered as excess carriers are generated in the sample, thereby producing a measurable signal indicative of the minority carrier lifetimes or recombination rates of the sample.

  13. NREL: Energy Storage - Battery Lifetime Analysis and Simulation Tool Suite

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Battery Lifetime Analysis and Simulation Tool Suite Lithium-ion (Li-ion) batteries used in EVs and stationary energy storage applications must be optimized to justify their high upfront costs. Given that batteries degrade with use and storage, strategies for optimization must factor in many years of use with a number of variables, including: Temperature State-of-charge histories Electricity current levels Cycle depth and frequency. These factors can all affect rates of battery degradation,

  14. Lifetime statistics of quantum chaos studied by a multiscale analysis

    SciTech Connect (OSTI)

    Di Falco, A.; Krauss, T. F. [School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, KY16 9SS (United Kingdom); Fratalocchi, A. [PRIMALIGHT, Faculty of Electrical Engineering, Applied Mathematics and Computational Science, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia)

    2012-04-30

    In a series of pump and probe experiments, we study the lifetime statistics of a quantum chaotic resonator when the number of open channels is greater than one. Our design embeds a stadium billiard into a two dimensional photonic crystal realized on a silicon-on-insulator substrate. We calculate resonances through a multiscale procedure that combines energy landscape analysis and wavelet transforms. Experimental data is found to follow the universal predictions arising from random matrix theory with an excellent level of agreement.

  15. Argon metastable dynamics and lifetimes in a direct current microdischarge

    SciTech Connect (OSTI)

    Stefanovi?, Ilija; Kuschel, Thomas; Schrter, Sandra; Bke, Marc

    2014-09-21

    In this paper we study the properties of a pulsed dc microdischarge with the continuous flow of argon. Argon metastable lifetimes are measured by tunable diode laser absorption spectroscopy (TDLAS) and are compared with calculated values which yield information about excitation and de-excitation processes. By increasing the gas flow-rate about 5 times from 10 to 50 sccm, the Ar{sup m} lifetime increases from 1 to 5 ?s due to the reduction of metastable quenching with gas impurities. Optical emission spectroscopy reveals nitrogen and water molecules as the main gas impurities. The estimated N? density [N?]=0.1% is too low to explain the measured metastable lifetimes. Water impurity was found to be the main de-excitation source of argon metastable atoms due to high quenching coefficients. The water impurity level of [H?O]=0.15% to 1% is sufficient to bring calculated metastable lifetimes in line with experiments. The maximum value of water content in the discharge compared to the argon atoms is estimated to approximately 6%, due to the large surface to volume ratio of the microdischarge. The current pulse releases the water molecules from the electrode surface and they are either re-adsorbed in the time between 0.4 ms for [H?O]=1% and 2.6 ms for [H?O]=0.15% or pumped out of the discharge with the speed equal to the gas flow-rate. Depending on its partial pressure, the water impurity re-adsorption time is of the order of magnitude or less then the argon gas residence time.

  16. Orientation-Dependent Entanglement Lifetime in a Squeezed Atomic Clock

    SciTech Connect (OSTI)

    Leroux, Ian D.; Schleier-Smith, Monika H.; Vuletic, Vladan

    2010-06-25

    We study experimentally the application of a class of entangled states, squeezed spin states, to the improvement of atomic-clock precision. In the presence of anisotropic noise, the entanglement lifetime is strongly dependent on squeezing orientation. We measure the Allan deviation spectrum of a clock operated with a phase-squeezed input state. For averaging times up to 50 s the squeezed clock achieves a given precision 2.8(3) times faster than a clock operating at the standard quantum limit.

  17. Apparatus for measuring minority carrier lifetime using liquid conductor -

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Energy Innovation Portal Industrial Technologies Industrial Technologies Find More Like This Return to Search Apparatus for measuring minority carrier lifetime using liquid conductor National Renewable Energy Laboratory Contact NREL About This Technology Technology Marketing Summary Solar power generating capacity has grown from 83 MW in 2003 to over 7,200 MW in 2012, in the U.S. alone. As the solar industry grows, there is a significant need for quality control and testing methodologies.

  18. Center for Extended Lifetime Energy Storage Technologies (CELESTE)

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Center for Extended Lifetime Energy Storage TEchnologies CELESTE Jim Misewich, Ph.D Esther S. Takeuchi, Ph.D.. Associate Laboratory Director SUNY Distinguished Professor Brookhaven National Laboratory Stony Brook University Messages National Needs for Electrical Energy Storage Transportation needs Grid needs Opportunity $120M DOE Energy Innovation Hub Competition (FOA-0000559) Brookhaven Track Record as Model for Hub GE and utilization of NSLS for Durathon TM Vision for CELESTE Leverage >$1B

  19. Predictive Models of Li-ion Battery Lifetime (Presentation)

    SciTech Connect (OSTI)

    Smith, K.; Wood, E.; Santhanagopalan, S.; Kim, G.; Shi, Y.; Pesaran, A.

    2014-09-01

    Predictive models of Li-ion battery reliability must consider a multiplicity of electrochemical, thermal and mechanical degradation modes experienced by batteries in application environments. Complicating matters, Li-ion batteries can experience several path dependent degradation trajectories dependent on storage and cycling history of the application environment. Rates of degradation are controlled by factors such as temperature history, electrochemical operating window, and charge/discharge rate. Lacking accurate models and tests, lifetime uncertainty must be absorbed by overdesign and warranty costs. Degradation models are needed that predict lifetime more accurately and with less test data. Models should also provide engineering feedback for next generation battery designs. This presentation reviews both multi-dimensional physical models and simpler, lumped surrogate models of battery electrochemical and mechanical degradation. Models are compared with cell- and pack-level aging data from commercial Li-ion chemistries. The analysis elucidates the relative importance of electrochemical and mechanical stress-induced degradation mechanisms in real-world operating environments. Opportunities for extending the lifetime of commercial battery systems are explored.

  20. Lifetime measurements of C 17 excited states and three-body and...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Journal Article: Lifetime measurements of C 17 excited ... Title: Lifetime measurements of C 17 excited states and three-body and continuum effects ...

  1. The effect of environment on thermal barrier coating lifetime

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Pint, Bruce A.; Unocic, Kinga A.; Haynes, James Allen

    2016-03-15

    While the water vapor content of the combustion gas in natural gas-fired land-based turbines is ~10%, it can be 20–85% with coal-derived (syngas or H2) fuels or innovative turbine concepts for more efficient carbon capture. Additional concepts envisage working fluids with high CO2 contents to facilitate carbon capture and sequestration. To investigate the effects of changes in the gas composition on thermal barrier coating (TBC) lifetime, furnace cycling tests (1-h and 100-h cycles) were performed in air with 10, 50, and 90 vol. % water vapor and CO2-10% H2O and compared to prior results in dry air or O2. Twomore » types of TBCs were investigated: (1) diffusion bond coatings (Pt-diffusion or Pt-modified aluminide) with commercial electron-beam physical vapor-deposited yttria-stabilized zirconia (YSZ) top coatings on second-generation superalloy N5 and N515 substrates and (2) high-velocity oxygen fuel (HVOF) sprayed MCrAlYHfSi bond coatings with air plasma-sprayed YSZ top coatings on superalloys X4, 1483, or 247 substrates. For both types of coatings exposed in 1-h cycles, the addition of water vapor resulted in a decrease in coating lifetime, except for Pt-diffusion coatings which were unaffected by the environment. In 100-h cycles, environment was less critical, perhaps because coating failure was chemical (i.e., due to interdiffusion) rather than mechanical. As a result, in both 1-h and 100-h cycles, CO2 did not appear to have any negative effect on coating lifetime.« less

  2. Determination of the b_s lifetime using hadronic decays

    SciTech Connect (OSTI)

    Deisher, A.J.; /LBL, Berkeley

    2008-07-01

    The authors present a measurement of the B{sub s}{sup 0} meson lifetime using fully and partially reconstructed hadronic decays B{sub s}{sup 0} {yields} D{sub s}{sup -} {pi}{sup +}(X) followed by D{sub s}{sup -} {yields} {phi}{pi}{sup -}. The data sample was recorded with the CDF II detector at the Fermilab Tevatron and corresponds to an integrated luminosity of 1.3 fb{sup -1} from p{bar p} collisions at {radical}s = 1.96 TeV.

  3. B(s) mixing and B hadron lifetimes at CDF

    SciTech Connect (OSTI)

    Milnik, Michael; /Karlsruhe U., EKP

    2007-10-01

    We present the CDF results using 1.0 fb{sup -1} of data on the mixing frequency measurement in the B{sup 0}{sub s} system and the lifetime measurements of several B hadrons. We obtain {Delta}m{sub s} = 17.77 {+-} 0.1 {+-} 0.07 ps{sup -1} and c{tau}({Lambda}{sub b}) = 473.8 {+-} 23.1 {+-}3.5 {micro}m. The later one is more than 3{sigma} above the world average, but in reasonable agreement with HQE calculations.

  4. Cosmological neutrino mass detection: The Best probe of neutrino lifetime

    SciTech Connect (OSTI)

    Serpico, Pasquale D.; /Fermilab

    2007-01-01

    Future cosmological data may be sensitive to the effects of a finite sum of neutrino masses even as small as {approx}0.06 eV, the lower limit guaranteed by neutrino oscillation experiments. We show that a cosmological detection of neutrino mass at that level would improve by many orders of magnitude the existing limits on neutrino lifetime, and as a consequence on neutrino secret interactions with (quasi-)massless particles as in majoron models. On the other hand, neutrino decay may provide a way-out to explain a discrepancy {approx}< 0.1 eV between cosmic neutrino bounds and Lab data.

  5. Positron lifetime spectrometer using a DC positron beam

    DOE Patents [OSTI]

    Xu, Jun; Moxom, Jeremy

    2003-10-21

    An entrance grid is positioned in the incident beam path of a DC beam positron lifetime spectrometer. The electrical potential difference between the sample and the entrance grid provides simultaneous acceleration of both the primary positrons and the secondary electrons. The result is a reduction in the time spread induced by the energy distribution of the secondary electrons. In addition, the sample, sample holder, entrance grid, and entrance face of the multichannel plate electron detector assembly are made parallel to each other, and are arranged at a tilt angle to the axis of the positron beam to effectively separate the path of the secondary electrons from the path of the incident positrons.

  6. Modified clock inequalities and modified black hole lifetime

    SciTech Connect (OSTI)

    Yang Rongjia; Zhang Shuangnan

    2009-06-15

    Based on a generalized uncertainty principle, Salecker-Wigner inequalities are modified. When applied to black holes, they give a modified black hole lifetime: T{sub MB}{approx}(M{sup 3}/m{sub p}{sup 3})(1-m{sub p}{sup 2}/M{sup 2})t{sub p}, and the number of bits required to specify the information content of the black hole as the event horizon area in Planck units N{approx}(M{sup 2}/m{sub p}{sup 2})(1-m{sub p}{sup 2}/M{sup 2})

  7. Apparatus for measuring minority carrier lifetimes in semiconductor materials

    DOE Patents [OSTI]

    Ahrenkiel, R.K.

    1999-07-27

    An apparatus for determining the minority carrier lifetime of a semiconductor sample includes a positioner for moving the sample relative to a coil. The coil is connected to a bridge circuit such that the impedance of one arm of the bridge circuit is varied as sample is positioned relative to the coil. The sample is positioned relative to the coil such that any change in the photoconductance of the sample created by illumination of the sample creates a linearly related change in the input impedance of the bridge circuit. In addition, the apparatus is calibrated to work at a fixed frequency so that the apparatus maintains a consistently high sensitivity and high linearly for samples of different sizes, shapes, and material properties. When a light source illuminates the sample, the impedance of the bridge circuit is altered as excess carriers are generated in the sample, thereby producing a measurable signal indicative of the minority carrier lifetimes or recombination rates of the sample. 17 figs.

  8. Measurements of aperture and beam lifetime using movable beam scrapers in Indus-2 electron storage ring

    SciTech Connect (OSTI)

    Kumar, Pradeep; Ghodke, A. D.; Karnewar, A. K.; Holikatti, A. C.; Yadav, S.; Puntambekar, T. A.; Singh, G.; Singh, P.

    2013-12-15

    In this paper, the measurements of vertical and horizontal aperture which are available for stable beam motion in Indus-2 at beam energy 2.5 GeV using movable beam scrapers are presented. These beam scrapers are installed in one of the long straight sections in the ring. With the movement of beam scrapers towards the beam centre, the beam lifetime is measured. The beam lifetime data obtained from the movement of vertical and horizontal beam scrapers are analyzed. The contribution of beam loss due to beam-gas scattering (vacuum lifetime) and electron-electron scattering within a beam bunch (Touschek lifetime) is separated from the measured beam lifetime at different positions of the beam scrapers. Vertical and horizontal beam sizes at scrapers location are estimated from the scraper movement towards the beam centre in quantum lifetime limit and their values closely agree with measured value obtained using X-ray diagnostic beamline.

  9. LIFETIME PREDICTION FOR MODEL 9975 O-RINGS IN KAMS

    SciTech Connect (OSTI)

    Hoffman, E.; Skidmore, E.

    2009-11-24

    The Savannah River Site (SRS) is currently storing plutonium materials in the K-Area Materials Storage (KAMS) facility. The materials are packaged per the DOE 3013 Standard and transported and stored in KAMS in Model 9975 shipping packages, which include double containment vessels sealed with dual O-rings made of Parker Seals compound V0835-75 (based on Viton{reg_sign} GLT). The outer O-ring of each containment vessel is credited for leaktight containment per ANSI N14.5. O-ring service life depends on many factors, including the failure criterion, environmental conditions, overall design, fabrication quality and assembly practices. A preliminary life prediction model has been developed for the V0835-75 O-rings in KAMS. The conservative model is based primarily on long-term compression stress relaxation (CSR) experiments and Arrhenius accelerated-aging methodology. For model development purposes, seal lifetime is defined as a 90% loss of measurable sealing force. Thus far, CSR experiments have only reached this target level of degradation at temperatures {ge} 300 F. At lower temperatures, relaxation values are more tolerable. Using time-temperature superposition principles, the conservative model predicts a service life of approximately 20-25 years at a constant seal temperature of 175 F. This represents a maximum payload package at a constant ambient temperature of 104 F, the highest recorded in KAMS to date. This is considered a highly conservative value as such ambient temperatures are only reached on occasion and for short durations. The presence of fiberboard in the package minimizes the impact of such temperature swings, with many hours to several days required for seal temperatures to respond proportionately. At 85 F ambient, a more realistic but still conservative value, bounding seal temperatures are reduced to {approx}158 F, with an estimated seal lifetime of {approx}35-45 years. The actual service life for O-rings in a maximum wattage package likely lies

  10. Small inner companions of warm Jupiters: Lifetimes and legacies

    SciTech Connect (OSTI)

    Van Laerhoven, Christa; Greenberg, Richard

    2013-12-01

    Although warm Jupiters are generally too far from their stars for tides to be important, the presence of an inner planetary companion to a warm Jupiter can result in tidal evolution of the system. Insight into the process and its effects comes form classical secular theory of planetary perturbations. The lifetime of the inner planet may be shorter than the age of the system, because the warm Jupiter maintains its eccentricity and hence promotes tidal migration into the star. Thus a warm Jupiter observed to be alone in its system might have previously cleared away any interior planets. Before its demise, even if an inner planet is of terrestrial scale, it may promote damping of the warm Jupiter's eccentricity. Thus any inferences of the initial orbit of an observed warm Jupiter must include the possibility of a greater initial eccentricity than would be estimated by assuming it had always been alone. Tidal evolution involving multiple planets also enhances the internal heating of the planets, which readily exceeds that of stellar radiation for the inner planet, and may be great enough to affect the internal structure of warm Jupiters. Secular theory gives insight into the tidal processes, providing, among other things, a way to constrain eccentricities of transiting planets based on estimates of the tidal parameter Q.

  11. Lifetime survivability of contaminated target-chamber optics

    SciTech Connect (OSTI)

    Rainer, F.; Anderson, A.; Burnham, A.; Milam, D.; Turner, R.

    1996-11-01

    Target chambers used for Inertial Confinement Fusion (ICF) expose laser optics to a very hostile environment, not only from high-fluence laser irradiation but also x-ray irradiation and particulate debris from targets and chamber wall materials. Expendable debris shields provide the first line of defense to more costly optics upstream in the laser beam path to contaminants generated within the target chamber. However, the replacement of a large number of debris shields is also an expensive proposition so that extending their usable lifetime within the chamber is important. We have conducted tests to show that optics can both be cleaned and damaged by laser irradiation at 355 nm after being contaminated with potential chamber-wall materials such as B{sub 4}C and Al{sub 2}O{sub 3}. Such optics can survive from one to hundreds of laser shots, depending on degree of contamination and laser fluence levels. Similarly, we have studied the survivability of optics that have been exposed to direct contamination from representative target materials irradiated in the target chamber. We have also studied the effects on optics that were not directly exposed to targets, yet received secondary exposure from the above directly-exposed samples.

  12. Accelerated stress rupture lifetime assessment for fiber composites

    SciTech Connect (OSTI)

    Groves, S.E.; DeTeresa, S.J.; Sanchez, R.J.; Zocher, M.A.; Christensen, R.M.

    1997-02-01

    Objective was to develop a theoretical and experimental framework for predicting stress rupture lifetime for fiber polymer composites based on short-term accelerated testing. Originally a 3-year project, it was terminated after the first year, which included stress rupture experiments and viscoelastic material characterization. In principle, higher temperature, stress, and saturated environmental conditions are used to accelerate stress rupture. Two types of specimens were to be subjected to long-term and accelerated static tensile loading at various temperatures, loads in order to quantify both fiber and matrix dominated failures. Also, we were to apply state-of-the-art analytical and experimental characterization techniques developed under a previous DOE/DP CRADA for capturing and tracking incipient degradation mechanisms associated with mechanical performance. Focus was increase our confidence to design, analyze, and build long-term composite structures such as flywheels and hydrogen gas storage vessels; other applications include advanced conventional weapons, infrastructures, marine and offshore systems, and stockpile stewardship and surveillance. Capabilities developed under this project, though not completed or verified, are being applied to NIF, AVLIS, and SSMP programs.

  13. Lifetime measurements in {sup 63}Co and {sup 65}Co

    SciTech Connect (OSTI)

    Dijon, A.; Clement, E.; France, G. de; Van Isacker, P.; Rejmund, M.; Schmitt, C.; Goergen, A.; Obertelli, A.; Korten, W.; Dewald, A.; Hackstein, M.; Pissulla, Th.; Rother, W.; Zell, K. O.; Gadea, A.; Gaudefroy, L.; Mengoni, D.; Recchia, F.; Sahin, E.

    2011-06-15

    Lifetimes of the 9/2{sub 1}{sup -} and 3/2{sub 1}{sup -} states in {sup 63}Co and the 9/2{sub 1}{sup -} state in {sup 65}Co were measured using the recoil distance Doppler shift and the differential decay curve methods. The nuclei were populated by multinucleon transfer reactions in inverse kinematics. {gamma} rays were measured with the EXOGAM Ge array and the recoiling fragments were fully identified using the large-acceptance VAMOS spectrometer. The E2 transition probabilities from the 3/2{sub 1}{sup -} and 9/2{sub 1}{sup -} states to the 7/2{sup -} ground state could be extracted in {sup 63}Co as well as an upper limit for the 9/2{sub 1}{sup -}{yields}7/2{sub 1}{sup -} B(E2) value in {sup 65}Co. The experimental results were compared to large-scale shell-model calculations in the pf and pfg{sub 9/2} model spaces, allowing us to draw conclusions on the single-particle or collective nature of the various states.

  14. Battery Lifetime Analysis and Simulation Tool (BLAST) Documentation

    SciTech Connect (OSTI)

    Neubauer, J.

    2014-12-01

    The deployment and use of lithium-ion batteries in automotive and stationary energy storage applications must be optimized to justify their high up-front costs. Given that batteries degrade with use and storage, such optimizations must evaluate many years of operation. As the degradation mechanisms are sensitive to temperature, state-of-charge histories, current levels, and cycle depth and frequency, it is important to model both the battery and the application to a high level of detail to ensure battery response is accurately predicted. To address these issues, the National Renewable Energy Laboratory has developed the Battery Lifetime Analysis and Simulation Tool (BLAST) suite of tools. This suite of tools pairs NREL's high-fidelity battery degradation model with a battery electrical and thermal performance model, application-specific electrical and thermal performance models of the larger system (e.g., an electric vehicle), application-specific system use data (e.g., vehicle travel patterns and driving data), and historic climate data from cities across the United States. This provides highly realistic, long-term predictions of battery response and thereby enables quantitative comparisons of varied battery use strategies.

  15. Window shopping

    SciTech Connect (OSTI)

    Best, D.

    1990-03-01

    The author addresses the energy efficiency of windows and describes changes and new products available in this consumer information article. Experiments currently being done by Lawrence Berkeley Laboratory (LBL), Bonneville Power Authority and the Washington State Energy Office show that some of these superwindows collect more energy from the sun than they let escape from inside the home. One type of window in current production is the low-E (low-emissivity) and the IGUs (insulated glass units). Low-E techniques include glazing of the glass with various materials including polyester and metallic coatings. Other measures include filling the airspace in double pane windows with argon, aerogel or by creating a vacuum in the airspace. Another factor the author considers is ultraviolet light protection.

  16. Environment and the Lifetime of Tropical Deep Convection in a Cloud-Permitting Regional Model Simulation

    SciTech Connect (OSTI)

    Hagos, Samson M.; Feng, Zhe; McFarlane, Sally A.; Leung, Lai-Yung R.

    2013-08-01

    By applying a cloud tracking algorithm to tropical convective systems simulated by a regional high resolution model, the study documents environmental conditions before and after convective systems are initiated over ocean and land by following them during their lifetime. The comparative roles of various environmental fields in affecting the lifetime of convection are also quantified. The statistics of lifetime, maximum area, propagation speed and direction of the simulated deep convection agrees well with geostationary satellite observations. Over ocean, convective systems enhance surface fluxes through the associated wind gusts as well as cooling and drying of the boundary layer. A significant relationship is found between the mean surface fluxes during their lifetime and the longevity of the systems which in turn is related to the initial intensity of the moist updraft and to a lesser extent upper level shear. Over land, on the other hand, convective activity suppresses surface fluxes through cloud cover and the lifetime of convection is related to the upper level shear during their lifetime and strength of the heat fluxes several hours before the initiation of convection. For systems of equal lifetime, those over land are significantly more intense than those over ocean especially during early stages of their lifetime.

  17. Inequivalence of single-particle and population lifetimes in a cuprate superconductor

    SciTech Connect (OSTI)

    Yang, Shuolong; Sobota, J. A.; Leuenberger, D.; He, Y.; Hashimoto, M.; Lu, D. H.; Eisaki, H.; Kirchmann, P. S.; Shen, Z. -X.

    2015-06-15

    We study optimally doped Bi-2212 (Tc=96 K) using femtosecond time- and angle-resolved photoelectron spectroscopy. Energy-resolved population lifetimes are extracted and compared with single-particle lifetimes measured by equilibrium photoemission. The population lifetimes deviate from the single-particle lifetimes in the low excitation limit by 1–2 orders of magnitude. Fundamental considerations of electron scattering unveil that these two lifetimes are in general distinct, yet for systems with only electron-phonon scattering they should converge in the low-temperature, low-fluence limit. As a result, the qualitative disparity in our data, even in this limit, suggests that scattering channels beyond electron-phonon interactions play a significant role in the electron dynamics of cuprate superconductors.

  18. Los Alamos National Laboratory W76 Pit Tube Lifetime Study

    SciTech Connect (OSTI)

    Abeln, Terri G.

    2012-04-25

    A metallurgical study was requested as part of the Los Alamos National Laboratory (LANL) W76-1 life-extension program (LEP) involving a lifetime analysis of type 304 stainless steel pit tubes subject to repeat bending loads during assembly and disassembly operations at BWXT/Pantex. This initial test phase was completed during the calendar years of 2004-2006 and the report not issued until additional recommended tests could be performed. These tests have not been funded to this date and therefore this report is considered final. Tubes were reportedly fabricated according to Rocky Flats specification P14548 - Seamless Type 304 VIM/VAR Stainless Steel Tubing. Tube diameter was specified as 0.125 inches and wall thickness as 0.028 inches. A heat treat condition is not specified and the hardness range specification can be characteristic of both 1/8 and 1/4 hard conditions. Properties of all tubes tested were within specification. Metallographic analysis could not conclusively determine a specified limit to number of bends allowable. A statistical analysis suggests a range of 5-7 bends with a 99.95% confidence limit. See the 'Statistical Analysis' section of this report. The initial phase of this study involved two separate sets of test specimens. The first group was part of an investigation originating in the ESA-GTS [now Gas Transfer Systems (W-7) Group]. After the bend cycle test parameters were chosen (all three required bends subjected to the same amount of bend cycles) and the tubes bent, the investigation was transferred to Terri Abeln (Metallurgical Science and Engineering) for analysis. Subsequently, another limited quantity of tubes became available for testing and were cycled with the same bending fixture, but with different test parameters determined by T. Abeln.

  19. On the low carrier lifetime edge zone in multicrystalline silicon ingots

    SciTech Connect (OSTI)

    Jiang, Tingting; Yu, Xuegong; Wang, Lei; Gu, Xin; Yang, Deren

    2014-01-07

    We have demonstrated the cause of low minority carrier lifetime corresponding to the edge zone of casting multicrystalline silicon ingots and its influence on the performance of solar cells. It is found that the concentration of substitutional carbon, interstitial oxygen, and dislocation density have no direct correlation with the low minority carrier lifetime in the edge zone. However, the distribution of interstitial iron exactly coincides with the minority carrier lifetime, indicating that iron contamination is mainly responsible for the lifetime degradation. After phosphorus diffusion gettering process, the low carrier lifetime region became narrower, and the concentration of interstitial iron is reduced by almost one order of magnitude. However, the carrier lifetime in the edge zone cannot be raised to average level. After celling process, the internal quantum efficiency map of the edge zone has a lower response to the long wavelength light, in accordance with the minority carrier lifetime distribution in this region. Therefore, the solar cells based on edge zones exhibit slightly lower efficiency than those conventional ones.

  20. Calculation of the extinction cross section and lifetime of a gold nanoparticle using FDTD simulations

    SciTech Connect (OSTI)

    Radhakrishnan, Archana; Murugesan, Dr V.

    2014-10-15

    The electromagnetic theory of light explains the behavior of light in most of the domains quite accurately. The problem arises when the exact solution of the Maxwell's equation is not present, in case of objects with arbitrary geometry. To find the extinction cross-section and lifetime of the gold nanoparticle, the software FDTD solutions 8.6 by Lumerical is employed. The extinction cross-sections and lifetimes of Gold nanospheres of different sizes and arrangements are studied using pulse lengths of the order of femtoseconds. The decay constant and other properties are compared. Further, the lifetimes are calculated using frequency and time domain calculations.

  1. Advanced Models and Controls for Prediction and Extension of Battery Lifetime (Presentation)

    SciTech Connect (OSTI)

    Smith, K.; Wood, E.; Santhanagopalan, S.; Kim, G.; Pesaran, A.

    2014-02-01

    Predictive models of capacity and power fade must consider a multiplicity of degradation modes experienced by Li-ion batteries in the automotive environment. Lacking accurate models and tests, lifetime uncertainty must presently be absorbed by overdesign and excess warranty costs. To reduce these costs and extend life, degradation models are under development that predict lifetime more accurately and with less test data. The lifetime models provide engineering feedback for cell, pack and system designs and are being incorporated into real-time control strategies.

  2. Using Minority Carrier Lifetime Measurement to Determine Saw Damage Characteristics on Si Wafer Surfaces

    SciTech Connect (OSTI)

    Sopori, Bhushan; Devayajanam, Srinivas; Basnyat, Prakash

    2015-06-14

    The damage on the Si wafer surfaces, caused by ingot cutting, is determined from measurement of minority carrier lifetime (..tau..eff). Samples are sequentially etched to remove thin layers from each surface and lifetime is measured after each etch step. The thickness-removed at which the lifetime reaches a peak value corresponds to the damage depth. This technique also allows the depth distribution of the damage to be quantified in terms of surface recombination velocity (SRV). An accurate measurement of ..tau..eff requires corrections to optical reflection, and transmission to account for changes in the surface morphology and in the wafer thickness.

  3. New Tool Quantitatively Maps Minority-Carrier Lifetime of Multicrystalline Silicon Bricks (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-11-01

    NREL's new imaging tool could provide manufacturers with insight on their processes. Scientists at the National Renewable Energy Laboratory (NREL) have used capabilities within the Process Development and Integration Laboratory (PDIL) to generate quantitative minority-carrier lifetime maps of multicrystalline silicon (mc-Si) bricks. This feat has been accomplished by using the PDIL's photoluminescence (PL) imaging system in conjunction with transient lifetime measurements obtained using a custom NREL-designed resonance-coupled photoconductive decay (RCPCD) system. PL imaging can obtain rapid high-resolution images that provide a qualitative assessment of the material lifetime-with the lifetime proportional to the pixel intensity. In contrast, the RCPCD technique provides a fast quantitative measure of the lifetime with a lower resolution and penetrates millimeters into the mc-Si brick, providing information on bulk lifetimes and material quality. This technique contrasts with commercially available minority-carrier lifetime mapping systems that use microwave conductivity measurements. Such measurements are dominated by surface recombination and lack information on the material quality within the bulk of the brick. By combining these two complementary techniques, we obtain high-resolution lifetime maps at very fast data acquisition times-attributes necessary for a production-based diagnostic tool. These bulk lifetime measurements provide manufacturers with invaluable feedback on their silicon ingot casting processes. NREL has been applying the PL images of lifetime in mc-Si bricks in collaboration with a U.S. photovoltaic industry partner through Recovery Act Funded Project ARRA T24. NREL developed a new tool to quantitatively map minority-carrier lifetime of multicrystalline silicon bricks by using photoluminescence imaging in conjunction with resonance-coupled photoconductive decay measurements. Researchers are not hindered by surface recombination and can look

  4. Correlation of CsK2Sb photocathode lifetime with antimony thickness

    SciTech Connect (OSTI)

    Mamun, M. A.; Hernandez-Garcia, C.; Poelker, M.; Elmustafa, A. A.

    2015-06-01

    CsK2Sb photocathodes with quantum efficiency on the order of 10% at 532 nm, and lifetime greater than 90 days at low voltage, were successfully manufactured via co-deposition of alkali species emanating from an effusion source. Photocathodes were characterized as a function of antimony layer thickness and alkali consumption, inside a vacuum chamber that was initially baked, but frequently vented without re-baking. Photocathode lifetime measured at low voltage is correlated with the antimony layer thickness. Photocathodes manufactured with comparatively thick antimony layers exhibited the best lifetime. We speculate that the antimony layer serves as a reservoir, or sponge, for the alkali.

  5. University Of Michigan Develops Innovative Strategy For Increasing Lifetime of Blue Phosphorescent Oleds

    Broader source: Energy.gov [DOE]

    The performance of phosphorescent OLEDs (PHOLEDs) has long been constrained by the short lifetime of the blue OLED component. With the help of DOE funding, the University of Michigan – in...

  6. Lifetime measurements of high-lying short lived states in {sup 69}As

    SciTech Connect (OSTI)

    Matejska-Minda, M.; Bednarczyk, P.; Fornal, B.; Ciemala, M.; Kmiecik, M.; Krzysiek, M.; Maj, A.; Meczynski, W.; Myalski, S.; Styczen, J.; Zieblinski, M.; Angelis, G. de; Huyuk, T.; Michelagnoli, C.; Sahin, E.; Aydin, S.; Farnea, E.; Menegazzo, R.; Recchia, F.; Ur, C. A.; and others

    2012-10-20

    Lifetimes of high-spin states in {sup 69}As have been measured using Doppler shift attenuation technique with the GASP and RFD setup. The determined transition probabilities indicate large deformation associated with some rotational bands in this nucleus.

  7. The Impact of PV Module Reliability on Plant Lifetimes Exceeding 25 Years |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy The Impact of PV Module Reliability on Plant Lifetimes Exceeding 25 Years The Impact of PV Module Reliability on Plant Lifetimes Exceeding 25 Years Presented at the PV Module Reliability Workshop, February 26 - 27 2013, Golden, Colorado pvmrw13_ps1_saic_mcclung.pdf (822.54 KB) More Documents & Publications Investigation of Direct Injection Vehicle Particulate Matter Emissions Model-Based Transient Calibration Optimization for Next Generation Diesel Engines USABC

  8. A portable time-domain LED fluorimeter for nanosecond fluorescence lifetime measurements

    SciTech Connect (OSTI)

    Wang, Hongtao; Salthouse, Christopher D.; Qi, Ying; Mountziaris, T. J.; Chemical Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003

    2014-05-15

    Fluorescence lifetime measurements are becoming increasingly important in chemical and biological research. Time-domain lifetime measurements offer fluorescence multiplexing and improved handling of interferers compared with the frequency-domain technique. In this paper, an all solid-state, filterless, and highly portable light-emitting-diode based time-domain fluorimeter (LED TDF) is reported for the measurement of nanosecond fluorescence lifetimes. LED based excitation provides more wavelengths options compared to laser diode based excitation, but the excitation is less effective due to the uncollimated beam, less optical power, and longer latency in state transition. Pulse triggering and pre-bias techniques were implemented in our LED TDF to improve the peak optical power to over 100 mW. The proposed pulsing circuit achieved an excitation light fall time of less than 2 ns. Electrical resetting technique realized a time-gated photo-detector to remove the interference of the excitation light with fluorescence. These techniques allow the LED fluorimeter to accurately measure the fluorescence lifetime of fluorescein down to concentration of 0.5 μM. In addition, all filters required in traditional instruments are eliminated for the non-attenuated excitation/emission light power. These achievements make the reported device attractive to biochemical laboratories seeking for highly portable lifetime detection devices for developing sensors based on fluorescence lifetime changes. The device was initially validated by measuring the lifetimes of three commercial fluorophores and comparing them with reported lifetime data. It was subsequently used to characterize a ZnSe quantum dot based DNA sensor.

  9. Ratio of D/sup 0/ and D/sup +/ lifetimes from their semileptonic decays

    SciTech Connect (OSTI)

    Donaldson, G.J.

    1980-06-01

    The conventional expectation for the decays of D mesons assumes that the charm quark decays in the presence of light, spectator quarks and thus the lifetimes of both charged and uncharged states are equal. In this article, evidence is presented from DELCO (at SPEAR) that the D lifetimes are quite different for neutral and charged mesons, and the results which have also become available from other experiments are reviewed.

  10. Cascade Problems in Some Atomic Lifetime Measurements at a Heavy-Ion Storage Ring

    SciTech Connect (OSTI)

    Trabert, E; Hoffmann, J; Krantz, C; Wolf, A; Ishikawa, Y; Santana, J

    2008-10-09

    Lifetimes of 3s{sup 2}3p{sup k} ground configuration levels of Al-, Si-, P-, and S-like ions of Be, Co, and Ni have been measured at a heavy-ion storage ring. Some of the observed decay curves show strong evidence of cascade repopulation from specific 3d levels that feature lifetimes in the same multi-millisecond range as the levels of the ground configuration.

  11. Device Architecture and Lifetime Requirements for High Efficiency Multicrystalline Silicon Solar Cells

    SciTech Connect (OSTI)

    Wagner, H.; Hofstetter, J.; Mitchell, B.; Altermatt, P.; Buonassisi, T.

    2015-03-23

    We present a numerical simulation study of different multicrystalline silicon materials and solar cell architectures to understand today's efficiency limitations and future efficiency possibilities. We compare conventional full-area BSF and PERC solar cells to future cell designs with a gallium phosphide heteroemitter. For all designs, mc-Si materials with different excess carrier lifetime distributions are used as simulation input parameters to capture a broad range of materials. The results show that conventional solar cell designs are sufficient for generalized mean lifetimes between 40 – 90 μs, but do not give a clear advantage in terms of efficiency for higher mean lifetime mc-Si material because they are often limited by recombination in the phosphorus diffused emitter region. Heteroemitter designs instead increase in cell efficiency considerable up to generalized mean lifetimes of 380 μs because they are significantly less limited by recombination in the emitter and the bulk lifetime becomes more important. In conclusion, to benefit from increasing mc-Si lifetime, new cell designs, especially heteroemitter, are desirable.

  12. Robust Maximum Lifetime Routing and Energy Allocation in Wireless Sensor Networks

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Paschalidis, Ioannis Ch.; Wu, Ruomin

    2012-01-01

    We consider the maximum lifetime routing problem in wireless sensor networks in two settings: (a) when nodes’ initial energy is given and (b) when it is subject to optimization. The optimal solution and objective value provide optimal flows and the corresponding predicted lifetime, respectively. We stipulate that there is uncertainty in various network parameters (available energy and energy depletion rates). In setting (a) we show that for specific, yet typical, network topologies, the actual network lifetime will reach the predicted value with a probability that converges to zero as the number of nodes grows large. In setting (b) the samemore » result holds for all topologies. We develop a series of robust problem formulations, ranging from pessimistic to optimistic. A set of parameters enable the tuning of the conservatism of the formulation to obtain network flows with a desirably high probability that the corresponding lifetime prediction is achieved. We establish a number of properties for the robust network flows and energy allocations and provide numerical results to highlight the tradeoff between predicted lifetime and the probability achieved. Further, we analyze an interesting limiting regime of massively deployed sensor networks and essentially solve a continuous version of the problem.« less

  13. Determination of carrier lifetime and mobility in colloidal quantum dot films via impedance spectroscopy

    SciTech Connect (OSTI)

    Rath, Arup K.; Lasanta, Tania; Bernechea, Maria; Diedenhofen, Silke L.; Konstantatos, Gerasimos

    2014-02-10

    Impedance Spectroscopy (IS) proves to be a powerful tool for the determination of carrier lifetime and majority carrier mobility in colloidal quantum dot films. We employ IS to determine the carrier lifetime in PbS quantum dot Schottky solar cells with Al and we verify the validity of the technique via transient photovoltage. We also present a simple approach based on an RC model that allows the determination of carrier mobility in PbS quantum dot films and we corroborate the results via comparison with space charge limited measurements. In summary, we demonstrate the potential of IS to characterize key-to-photovoltaics optoelectronic properties, carrier lifetime, and mobility, in a facile way.

  14. Apparatus and methods of measuring minority carrier lifetime using a liquid probe

    DOE Patents [OSTI]

    Li, Jian

    2016-04-12

    Methods and apparatus for measuring minority carrier lifetimes using liquid probes are provided. In one embodiment, a method of measuring the minority carrier lifetime of a semiconductor material comprises: providing a semiconductor material having a surface; forming a rectifying junction at a first location on the surface by temporarily contacting the surface with a conductive liquid probe; electrically coupling a second junction to the semiconductor material at a second location, wherein the first location and the second location are physically separated; applying a forward bias to the rectifying junction causing minority carrier injection in the semiconductor material; measuring a total capacitance as a function of frequency between the rectifying junction and the second junction; determining an inflection frequency of the total capacitance; and determining a minority lifetime of the semiconductor material from the inflection frequency.

  15. Nuclear matrix elements from direct lifetime or cross-section measurements

    SciTech Connect (OSTI)

    Werner, V.; Cooper, N.; Hinton, M.; Ilie, G.; Radeck, D.

    2012-11-20

    The method of simultaneous lifetime and g factor measurements using a plunger device and the RDDS and TDRIV techniques is introduced. Results on lifetimes and hyperfine-interaction parameters for 2{sup +}{sub 1} states in {sup 104-108}Pd, {sup 96,98,104}Ru, and {sup 92,94}Zr, using a plunger device. Another method to obtain electromagnetic matrix elements is direct cross section measurements using NRF. The method is outlined, and some recent results on {sup 76}Se are shown.

  16. Apparatus and method for measuring fluorescence intensities at a plurality of wavelengths and lifetimes

    DOE Patents [OSTI]

    Buican, T.N.

    1993-05-04

    Apparatus and method is described for measuring intensities at a plurality of wavelengths and lifetimes. A source of multiple-wavelength electromagnetic radiation is passed through a first interferometer modulated at a first frequency, the output thereof being directed into a sample to be investigated. The light emitted from the sample as a result of the interaction thereof with the excitation radiation is directed into a second interferometer modulated at a second frequency, and the output detected and analyzed. In this manner excitation, emission, and lifetime information may be obtained for a multiplicity of fluorochromes in the sample.

  17. Apparatus and method for measuring fluorescence intensities at a plurality of wavelengths and lifetimes

    DOE Patents [OSTI]

    Buican, Tudor N.

    1993-01-01

    Apparatus and method for measuring intensities at a plurality of wavelengths and lifetimes. A source of multiple-wavelength electromagnetic radiation is passed through a first interferometer modulated at a first frequency, the output thereof being directed into a sample to be investigated. The light emitted from the sample as a result of the interaction thereof with the excitation radiation is directed into a second interferometer modulated at a second frequency, and the output detected and analyzed. In this manner excitation, emission, and lifetime information may be obtained for a multiplicity of fluorochomes in the sample.

  18. Measurement of the Masses and Lifetimes of B Hadrons at the Tevatron

    SciTech Connect (OSTI)

    Catastini, Pierluigi; /Pisa U. /INFN, Pisa

    2006-05-01

    The latest results for the B Hadron sector at the Tevatron Collider are summarized. The properties of B hadrons can be precisely measured at the Tevatron. In particularly they will focus on the masses and lifetimes. The new Tevatron results for the CP violation in B Hadrons are also discussed.

  19. Estimating service lifetimes of a polymer encapsulant for photovoltaic modules from accelerated testing

    SciTech Connect (OSTI)

    Czanderna, A.W.; Pern, F.J.

    1996-05-01

    In this paper, most of the emphasis is on A9918 ethylene vinyl acetate (EVA) used commercially as the pottant for encapsulating photovoltaic (PV) modules, in which the efficiencies in field-deployed modules have been reduced by 10-70% in 4-12 years. Yet, projections were made by several different research groups in the 1980s that the EVA lifetime could range from 2-100 years. The authors (1) elucidate the complexity of the encapsulation problem, (2) indicate the performance losses reported for PV systems deployed since 1981, (3) critically assess the service lifetime predictions for EVA as a PV pottant based on studies by others for which they review the inherent errors in their assumptions about the Arrhenius relation, (4) show how degradation of minimodules in laboratory experiments that simulate reality can produce efficiency losses comparable to those in field-degraded PV modules reported in the literature, and (5) outline an acceptable methodology for making a service lifetime prediction of the polymer encapsulant, including the essential need for relating accelerated lifetime testing to real-time testing with a sufficient number of samples.

  20. Minority carrier lifetimes in very long-wave infrared InAs/GaInSb superlattices

    SciTech Connect (OSTI)

    Olson, Benjamin Varberg; Haugan, Heather J.; Brown, Gail J.; Kadlec, Emil Andrew; Kim, Jin K.; Shaner, Eric A.

    2016-01-01

    Here, significantly improved carrier lifetimes in very-long wave infrared InAs/GaInSb superlattice(SL) absorbers are demonstrated by using time-resolved microwave reflectance (TMR) measurements. A nominal 47.0 Å InAs/21.5 Å Ga0.75In0.25Sb SLstructure that produces an approximately 25 μm response at 10 K has a minority carrier lifetime of 140 ± 20 ns at 18 K, which is markedly long for SL absorber with such a narrow bandgap. This improvement is attributed to the strain-engineered ternary design. Such SL employs a shorter period with reduced gallium in order to achieve good optical absorption and epitaxial advantages, which ultimately leads to the improvements in the minority carrier lifetime by reducing Shockley–Read–Hall (SRH) defects. By analyzing the temperature-dependence of TMR decay data, the recombination mechanisms and trap states that currently limit the performance of this SL absorber have been identified. The results show a general decrease in the long-decay lifetime component, which is dominated by the SRH recombination at temperature below ~30 K, and by Auger recombination at temperatures above ~45 K.

  1. Minority carrier lifetimes in very long-wave infrared InAs/GaInSb superlattices

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Olson, Benjamin Varberg; Haugan, Heather J.; Brown, Gail J.; Kadlec, Emil Andrew; Kim, Jin K.; Shaner, Eric A.

    2016-01-01

    Here, significantly improved carrier lifetimes in very-long wave infrared InAs/GaInSb superlattice(SL) absorbers are demonstrated by using time-resolved microwave reflectance (TMR) measurements. A nominal 47.0 Å InAs/21.5 Å Ga0.75In0.25Sb SLstructure that produces an approximately 25 μm response at 10 K has a minority carrier lifetime of 140 ± 20 ns at 18 K, which is markedly long for SL absorber with such a narrow bandgap. This improvement is attributed to the strain-engineered ternary design. Such SL employs a shorter period with reduced gallium in order to achieve good optical absorption and epitaxial advantages, which ultimately leads to the improvements in themore » minority carrier lifetime by reducing Shockley–Read–Hall (SRH) defects. By analyzing the temperature-dependence of TMR decay data, the recombination mechanisms and trap states that currently limit the performance of this SL absorber have been identified. The results show a general decrease in the long-decay lifetime component, which is dominated by the SRH recombination at temperature below ~30 K, and by Auger recombination at temperatures above ~45 K.« less

  2. Development of a high average current polarized electron source with long cathode operational lifetime

    SciTech Connect (OSTI)

    C. K. Sinclair; P. A. Adderley; B. M. Dunham; J. C. Hansknecht; P. Hartmann; M. Poelker; J. S. Price; P. M. Rutt; W. J. Schneider; M. Steigerwald

    2007-02-01

    Substantially more than half of the electromagnetic nuclear physics experiments conducted at the Continuous Electron Beam Accelerator Facility of the Thomas Jefferson National Accelerator Facility (Jefferson Laboratory) require highly polarized electron beams, often at high average current. Spin-polarized electrons are produced by photoemission from various GaAs-based semiconductor photocathodes, using circularly polarized laser light with photon energy slightly larger than the semiconductor band gap. The photocathodes are prepared by activation of the clean semiconductor surface to negative electron affinity using cesium and oxidation. Historically, in many laboratories worldwide, these photocathodes have had short operational lifetimes at high average current, and have often deteriorated fairly quickly in ultrahigh vacuum even without electron beam delivery. At Jefferson Lab, we have developed a polarized electron source in which the photocathodes degrade exceptionally slowly without electron emission, and in which ion back bombardment is the predominant mechanism limiting the operational lifetime of the cathodes during electron emission. We have reproducibly obtained cathode 1/e dark lifetimes over two years, and 1/e charge density and charge lifetimes during electron beam delivery of over 2?105???C/cm2 and 200 C, respectively. This source is able to support uninterrupted high average current polarized beam delivery to three experimental halls simultaneously for many months at a time. Many of the techniques we report here are directly applicable to the development of GaAs photoemission electron guns to deliver high average current, high brightness unpolarized beams.

  3. Lifetimes of the first excited 2{sup +} states in {sup 176,178,180}Os

    SciTech Connect (OSTI)

    Moeller, O.; Melon, B.; Dewald, A.; Fitzler, A.; Jolie, J.; Christen, S.; Saha, B.; Zell, K.O.; Heidemann, M.; Petkov, P.; Tonev, D.

    2005-09-01

    By use of the pulsed-beam technique, the lifetimes of the first excited 2{sup +} states in {sup 176,178}Os were measured for the first time and the lifetime of the 2{sub 1}{sup +} state in {sup 180}Os was determined to a greater accuracy. In addition, for {sup 178}Os, a recoil-distance Doppler-shift experiment and an experiment to measure the nuclear deorientation effect that is due to the hyperfine interactions were also performed. The results obtained from this measurement are consistent with the lifetime value extracted by means of the pulsed-beam experiment. As well, the lifetimes of two I{sup {pi}}=7{sup -} isomers in {sup 180}Os were determined more accurately. Together with previously published data for the even-even osmium isotopes, the newly determined B(E2,2{sub 1}{sup +}{yields}0{sub 1}{sup +}) transition strengths show a maximum value at the N=104 midshell. This maximum corresponds to the simple expectation of the N{sub {pi}}N{sub {nu}} rule of the interacting boson approximation (IBA) but remains to be explained by microscopic models.

  4. New lifetime measurements in Pd109 and the onset of deformation at N=60

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bucher, B.; Mach, H.; Aprahamian, A.; Simpson, G. S.; Rissanen, J.; Ghiţă, D. G.; Olaizola, B.; Kurcewicz, W.; Äystö, J.; Bentley, I.; et al

    2015-12-14

    We measured several new subnanosecond lifetimes in 109Pd using the fast-timing βγ γ (t ) method. Fission fragments of the A = 109 mass chain were produced by bombarding natural uranium with 30 MeV protons at the Jyväskylä Ion Guide Isotope Separator On-Line (IGISOL) facility. We obtained lifetimes for excited states in 109Pd populated following β decay of 109Rh. The new lifetimes provide some insight into the evolution of nuclear structure in this mass region. In particular, the distinct structure of the two low-lying 7/2+ states occurring systematically across the Pd isotopic chain is supported by the new lifetime measurements.more » Finally, the available nuclear data indicate a sudden increase in deformation at N = 60 which is related to the strong p-n interaction between πg9/2 and νg7/2 valence nucleons expected in this region.« less

  5. Phosphazene Based Additives for Improvement of Safety and Battery Lifetimes in Lithium-Ion Batteries

    SciTech Connect (OSTI)

    Mason K Harrup; Kevin L Gering; Harry W Rollins; Sergiy V Sazhin; Michael T Benson; David K Jamison; Christopher J Michelbacher

    2011-10-01

    There need to be significant improvements made in lithium-ion battery technology, principally in the areas of safety and useful lifetimes to truly enable widespread adoption of large format batteries for the electrification of the light transportation fleet. In order to effect the transition to lithium ion technology in a timely fashion, one promising next step is through improvements to the electrolyte in the form of novel additives that simultaneously improve safety and useful lifetimes without impairing performance characteristics over wide temperature and cycle duty ranges. Recent efforts in our laboratory have been focused on the development of such additives with all the requisite properties enumerated above. We present the results of the study of novel phosphazene based electrolytes additives.

  6. Direct Measurement of the Radiative Lifetime of Vibrationally Excited OH Radicals

    SciTech Connect (OSTI)

    Meerakker, Sebastiaan Y.T. van de; Vanhaecke, Nicolas; Meijer, Gerard; Loo, Mark P.J. van der; Groenenboom, Gerrit C.

    2005-07-01

    Neutral molecules, isolated in the gas phase, can be prepared in a long-lived excited state and stored in a trap. The long observation time afforded by the trap can then be exploited to measure the radiative lifetime of this state by monitoring the temporal decay of the population in the trap. This method is demonstrated here and used to benchmark the Einstein A coefficients in the Meinel system of OH. A pulsed beam of vibrationally excited OH radicals is Stark decelerated and loaded into an electrostatic quadrupole trap. The radiative lifetime of the upper {lambda}-doublet component of the X {sup 2}{pi}{sub 3/2}, v=1, J=3/2 level is determined as 59.0{+-}2.0 ms, in good agreement with the calculated value of 58.0{+-}1.0 ms.

  7. Nanostructure induced changes in lifetime and enhanced second-harmonic response of organic-plasmonic hybrids

    SciTech Connect (OSTI)

    Leißner, Till; Kostiučenko, Oksana; Rubahn, Horst-Günter; Fiutowski, Jacek; Brewer, Jonathan R.

    2015-12-21

    In this letter we show that the optical response of organic nanofibers, grown from functionalized para-quaterphenylene molecules, can be controlled by forming organic-plasmonic hybrid systems. The interaction between nanofibers and supporting regular arrays of nanostructures leads to a strongly enhanced second harmonic response. At the same time, the fluorescence lifetime of the nanofibers is reduced from 0.32 ns for unstructured gold films to 0.22 ns for gold nanosquare arrays, demonstrating efficient organic–plasmonic interaction. To study the origin of these effects, we applied two-photon laser scanning microscopy and fluorescence lifetime imaging microscopy. These findings provide an effective approach for plasmon-enhanced second-harmonic generation at the nanoscale, which is attractive for nanophotonic circuitry.

  8. Preliminary lifetime predictions for 304 stainless steel as the LANL ABC blanket material

    SciTech Connect (OSTI)

    Park, J.J.; Buksa, J.J.; Houts, M.G.; Arthur, E.D.

    1997-11-01

    The prediction of materials lifetime in the preconceptual Los Alamos National Laboratory (LANL) Accelerator-Based Conversion of Plutonium (ABC) is of utmost interest. Because Hastelloy N showed good corrosion resistance to the Oak Ridge National Laboratory Molten Salt Reactor Experiment fuel salt that is similar to the LANL ABC fuel salt, Hastelloy N was originally proposed for the LANL ABC blanket material. In this paper, the possibility of using 304 stainless steel as a replacement for the Hastelloy N is investigated in terms of corrosion issues and fluence-limit considerations. An attempt is made, based on the previous Fast Flux Test Facility design data, to predict the preliminary lifetime estimate of the 304 stainless steel used in the blanket region of the LANL ABC.

  9. Carrier-lifetime-controlled selective etching process for semiconductors using photochemical etching

    DOE Patents [OSTI]

    Ashby, Carol I. H.; Myers, David R.

    1992-01-01

    The minority carrier lifetime is significantly much shorter in semiconductor materials with very high impurity concentrations than it is in semiconductor materials with lower impurity concentration levels. This phenomenon of reduced minority carrier lifetime in semiconductor materials having high impurity concentration is utilized to advantage for permitting highly selective semiconductor material etching to be achieved using a carrier-driven photochemical etching reaction. Various means may be employed for increasing the local impurity concentration level in specific near-surface regions of a semiconductor prior to subjecting the semiconductor material to a carrier-driven photochemical etching reaction. The regions having the localized increased impurity concentration form a self-aligned mask inhibiting photochemical etching at such localized regions while the adjacent regions not having increased impurity concentrations are selectively photochemically etched. Liquid- or gas-phase etching may be performed.

  10. Influence of deep level defects on carrier lifetime in CdZnTe:In

    SciTech Connect (OSTI)

    Guo, Rongrong; Jie, Wanqi Wang, Ning; Zha, Gangqiang; Xu, Yadong; Wang, Tao; Fu, Xu

    2015-03-07

    The defect levels and carrier lifetime in CdZnTe:In crystal were characterized with photoluminescence, thermally stimulated current measurements, as well as contactless microwave photoconductivity decay (MWPCD) technique. An evaluation equation to extract the recombination lifetime and the reemission time from MWPCD signal is developed based on Hornbeck-Haynes trapping model. An excellent agreement between defect level distribution and carrier reemission time in MWPCD signal reveals the tail of the photoconductivity decay is controlled by the defect level reemission effect. Combining {sup 241}Am gamma ray radiation response measurement and laser beam induced transient current measurement, it predicted that defect level with the reemission time shorter than the collection time could lead to better charge collection efficiency of CdZnTe detector.

  11. Apparatus and method for measuring minority carrier lifetimes in semiconductor materials

    DOE Patents [OSTI]

    Ahrenkiel, Richard K.; Johnston, Steven W.

    2001-01-01

    An apparatus for determining the minority carrier lifetime of a semiconductor sample includes a positioner for moving the sample relative to a coil. The coil is connected to a bridge circuit such that the impedance of one arm of the bridge circuit is varied as sample is positioned relative to the coil. The sample is positioned relative to the coil such that any change in the photoconductance of the sample created by illumination of the sample creates a linearly related change in the input impedance of the bridge circuit. In addition, the apparatus is calibrated to work at a fixed frequency so that the apparatus maintains a consistently high sensitivity and high linearity for samples of different sizes, shapes, and material properties. When a light source illuminates the sample, the impedance of the bridge circuit is altered as excess carriers are generated in the sample, thereby producing a measurable signal indicative of the minority carrier lifetimes or recombination rates of the sample.

  12. Fluorescent lifetime measurements of rare-earth elements in gallium arsenide. Master's thesis

    SciTech Connect (OSTI)

    Topp, D.J.

    1990-12-01

    Lifetime measurements of the excited states of three GaAs semiconductors doped with the rare earth elements Erbium (Er), Praseodymium (Pr), and Thulium (Tm) has been studied using a pulsed nitrogen laser and germanium detector. The measurements were made with an experimental set up with a system response time of 0.34 microseconds. A 330 milliwatt nitrogen laser with a wavelength of 3370 angstroms was used to excite transitions of the rare earth elements.

  13. Investigation of in-vivo skin autofluorescence lifetimes under long-term cw optical excitation

    SciTech Connect (OSTI)

    Lihachev, A; Ferulova, I; Vasiljeva, K; Spigulis, J

    2014-08-31

    The main results obtained during the last five years in the field of laser-excited in-vivo human skin photobleaching effects are presented. The main achievements and results obtained, as well as methods and experimental devices are briefly described. In addition, the impact of long-term 405-nm cw low-power laser excitation on the skin autofluorescence lifetime is experimentally investigated. (laser biophotonics)

  14. Natural Radionuclides and Isotopic Signatures for Determining Carbonaceous Aerosol Sources, Aerosol Lifetimes, and Washout Processes

    SciTech Connect (OSTI)

    Gaffney, Jeffrey

    2012-12-12

    This is the final technical report. The project description is as follows: to determine the role of aerosol radiative forcing on climate, the processes that control their atmospheric concentrations must be understood, and aerosol sources need to be determined for mitigation. Measurements of naturally occurring radionuclides and stable isotopic signatures allow the sources, removal and transport processes, as well as atmospheric lifetimes of fine carbonaceous aerosols, to be evaluated.

  15. Modification of surface oxide layers of titanium targets for increasing lifetime of neutron tubes

    SciTech Connect (OSTI)

    Zakharov, A. M. Dvoichenkova, O. A.; Evsin, A. E.

    2015-12-15

    The peculiarities of interaction of hydrogen ions with a titanium target and its surface oxide layer were studied. Two ways of modification of the surface oxide layers of titanium targets for increasing the lifetime of neutron tubes were proposed: (1) deposition of an yttrium oxide barrier layer on the target surface; (2) implementation of neutron tube work regime in which the target is irradiated with ions with energies lower than 1000 eV between high-energy ion irradiation pulses.

  16. Minority carrier lifetime in iodine-doped molecular beam epitaxy-grown HgCdTe

    SciTech Connect (OSTI)

    Madni, I.; Umana-Membreno, G. A.; Lei, W.; Gu, R.; Antoszewski, J.; Faraone, L.

    2015-11-02

    The minority carrier lifetime in molecular beam epitaxy grown layers of iodine-doped Hg{sub 1−x}Cd{sub x}Te (x ∼ 0.3) on CdZnTe substrates has been studied. The samples demonstrated extrinsic donor behavior for carrier concentrations in the range from 2 × 10{sup 16} cm{sup −3} to 6 × 10{sup 17} cm{sup −3} without any post-growth annealing. At a temperature of 77 K, the electron mobility was found to vary from 10{sup 4} cm{sup 2}/V s to 7 × 10{sup 3} cm{sup 2}/V s and minority carrier lifetime from 1.6 μs to 790 ns, respectively, as the carrier concentration was increased from 2 × 10{sup 16} cm{sup −3} to 6 × 10{sup 17} cm{sup −3}. The diffusion of iodine is much lower than that of indium and hence a better alternative in heterostructures such as nBn devices. The influence of carrier concentration and temperature on the minority carrier lifetime was studied in order to characterize the carrier recombination mechanisms. Measured lifetimes were also analyzed and compared with the theoretical models of the various recombination processes occurring in these materials, indicating that Auger-1 recombination was predominant at higher doping levels. An increase in deep-level generation-recombination centers was observed with increasing doping level, which suggests that the increase in deep-level trap density is associated with the incorporation of higher concentrations of iodine into the HgCdTe.

  17. The emission wavelength dependent photoluminescence lifetime of the N-doped graphene quantum dots

    SciTech Connect (OSTI)

    Deng, Xingxia; Sun, Jing; Yang, Siwei; Ding, Guqiao; Shen, Hao; Zhou, Wei; Lu, Jian; Wang, Zhongyang

    2015-12-14

    Aromatic nitrogen doped graphene quantum dots were investigated by steady-state and time-resolved photoluminescence (PL) techniques. The PL lifetime was found to be dependent on the emission wavelength and coincident with the PL spectrum, which is different from most semiconductor quantum dots and fluorescent dyes. This result shows the synergy and competition between the quantum confinement effect and edge functional groups, which may have the potential to guide the synthesis and expand the applications of graphene quantum dots.

  18. Superfluid Phase Transition of Long-lifetime Polaritons | MIT-Harvard

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Center for Excitonics Superfluid Phase Transition of Long-lifetime Polaritons November 15, 2011 at 3pm/34-401A David Snoke Department of Physics and Astronomy, University of Pittsburgh Snoke002 Abstract: Polaritons are quasiparticles of electronic excitation in semiconductor structures with extremely light mass, about four orders of magnitude less than a free electron. Because of this very light mass, polaritons show Bose quantum effects even at moderate densities and temperatures from tens

  19. Radiative lifetimes of zincblende CdSe/CdS quantum dots

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gong, Ke; Martin, James E.; Shea-Rohwer, Lauren E.; Lu, Ping; Kelley, David F.

    2015-01-02

    Recent synthetic advances have made available very monodisperse zincblende CdSe/CdS quantum dots having near-unity photoluminescence quantum yields. Because of the absence of nonradiative decay pathways, accurate values of the radiative lifetimes can be obtained from time-resolved PL measurements. Radiative lifetimes can also be obtained from the Einstein relations, using the static absorption spectra and the relative thermal populations in the angular momentum sublevels. We found that one of the inputs into these calculations is the shell thickness, and it is useful to be able to determine shell thickness from spectroscopic measurements. We use an empirically corrected effective mass model tomore » produce a “map” of exciton wavelength as a function of core size and shell thickness. These calculations use an elastic continuum model and the known lattice and elastic constants to include the effect of lattice strain on the band gap energy. The map is in agreement with the known CdSe sizing curve and with the shell thicknesses of zincblende core/shell particles obtained from TEM images. Furthermore, if selenium–sulfur diffusion is included and lattice strain is omitted from the calculation then the resulting map is appropriate for wurtzite CdSe/CdS quantum dots synthesized at high temperatures, and this map is very similar to one previously reported (J. Am. Chem. Soc. 2009, 131, 14299). Radiative lifetimes determined from time-resolved measurements are compared to values obtained from the Einstein relations, and found to be in excellent agreement. For a specific core size (2.64 nm diameter, in the present case), radiative lifetimes are found to decrease with increasing shell thickness. Thus, this is similar to the size dependence of one-component CdSe quantum dots and in contrast to the size dependence in type-II quantum dots.« less

  20. An application of a zero-inflated lifetime distribution with multiple and incomplete data sources

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hamada, M. S.; Margevicius, K. J.

    2016-02-11

    In this study, we analyze data sampled from a population of parts in which an associated anomaly can occur at assembly or after assembly. Using a zero-inflated lifetime distribution to fit left-censored and right-censored data as well data from a supplementary sample, we make predictions about the proportion of the population with anomalies today and in the future. Goodness-of-fit is also addressed.

  1. Polymer Electrolyte Fuel Cell Lifetime Limitations: The Role of Electrocatalyst Degradation

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Electrolyte Fuel Cell Lifetime Limitations: The Role of Electrocatalyst Degradation Debbie Myers and Xiaoping Wang - Argonne National Laboratory Graham Hards, Sarah Ball, and Jonathan Sharman - Johnson Matthey Fuel Cells Mallika Gummalla - United Technologies Research Center Yang Shao-Horn - Massachusetts Institute of Technology Paulo Ferreira - University of Texas at Austin Dane Morgan - University of Wisconsin - Madison Jeremy Meyers - University of Texas at Austin Fuel Cell Technologies

  2. Radiative lifetimes of zincblende CdSe/CdS quantum dots

    SciTech Connect (OSTI)

    Gong, Ke; Martin, James E.; Shea-Rohwer, Lauren E.; Lu, Ping; Kelley, David F.

    2015-01-02

    Recent synthetic advances have made available very monodisperse zincblende CdSe/CdS quantum dots having near-unity photoluminescence quantum yields. Because of the absence of nonradiative decay pathways, accurate values of the radiative lifetimes can be obtained from time-resolved PL measurements. Radiative lifetimes can also be obtained from the Einstein relations, using the static absorption spectra and the relative thermal populations in the angular momentum sublevels. We found that one of the inputs into these calculations is the shell thickness, and it is useful to be able to determine shell thickness from spectroscopic measurements. We use an empirically corrected effective mass model to produce a “map” of exciton wavelength as a function of core size and shell thickness. These calculations use an elastic continuum model and the known lattice and elastic constants to include the effect of lattice strain on the band gap energy. The map is in agreement with the known CdSe sizing curve and with the shell thicknesses of zincblende core/shell particles obtained from TEM images. Furthermore, if selenium–sulfur diffusion is included and lattice strain is omitted from the calculation then the resulting map is appropriate for wurtzite CdSe/CdS quantum dots synthesized at high temperatures, and this map is very similar to one previously reported (J. Am. Chem. Soc. 2009, 131, 14299). Radiative lifetimes determined from time-resolved measurements are compared to values obtained from the Einstein relations, and found to be in excellent agreement. For a specific core size (2.64 nm diameter, in the present case), radiative lifetimes are found to decrease with increasing shell thickness. Thus, this is similar to the size dependence of one-component CdSe quantum dots and in contrast to the size dependence in type-II quantum dots.

  3. Source fabrication and lifetime for Li+ ion beams extracted from alumino-silicate sources

    SciTech Connect (OSTI)

    Roy, Prabir K.; Greenway, Wayne G.; Kwan, Joe W

    2012-03-05

    A space-charge-limited beam with current densities (J) exceeding 1 mA/cm{sup 2} have been measured from lithium alumino-silicate ion sources at a temperature of #24;~1275#14;{degrees} C. At higher extraction voltages, the source appears to become emission limited with J #21;{>=} 1.5 mA/cm{sup 2}, and J increases weakly with the applied voltage. A 6.35 mm diameter source with an alumino-silicate coating, {<=}#20;0.25 mm thick, has a measured lifetime of ~#24;40 hours at ~#24;1275#14;{degrees} C, when pulsed at 0.05 Hz and with pulse length of #24;~6 μs each. At this rate, the source lifetime was independent of the actual beam charge extracted due to the loss of neutral atoms at high temperature. The source lifetime increases with the amount of alumino-silicate coated on the emitting surface, and may also be further extended if the temperature is reduced between pulses.

  4. Measurement of D0 lifetime with the BaBar detector

    SciTech Connect (OSTI)

    Simi, Gabriele; /Pisa U. /SLAC

    2009-12-17

    This work is the result of the researchers carried out during a three years Ph.D. period in the BABAR experiment. The first chapter consists in an introduction to the theoretical aspects of the D{sup 0} meson lifetime determination and CP violation parameters, as well as an overview of the CP violation in the B sector, which is the main topic of the experiment. The description of the experimental apparatus follows with particular attention to the Silicon Vertex Tracker detector, the most critical detector for the determination of decay vertices and thus of lifetimes and time dependent CP violation asymmetries. In the fourth chapter the operation and running of the vertex detector is described, as a result from the experience as Operation Manager of the SVT, with particular attention to the safety of the device and the data quality assurance. The last chapter is dedicated to the determination of the D{sup 0} meson lifetime with the BABAR detector, which is the main data analysis carried out by the candidate. The analysis is characterized by the selection of an extremely pure sample of D{sup 0} mesons for which the decay flight length and proper time is reconstructed. The description of the unbinned maximum likelihood fit follows, as well as the discussion of the possible sources of systematic uncertainties. In the appendix is also presented a preliminary study of a possible development regarding the determination of mixing and CP violation parameters for the D{sup 0} meson.

  5. Analysis of Lifetime Data for the Linac 201 MHz Power Amplifiers

    SciTech Connect (OSTI)

    Elliot McCrory and Robert C. Webber

    2002-07-09

    This document analyzes data on the lifetime of the 201-MHz triode power amplifier (PA) vacuum tube, model number 7835, used in the low-energy half of the Linac. We observe that a 7835 power amplifier vacuum tube has historically provided about one and one-third years service in the Linac. The lifetime of recently re-manufactured tubes is somewhat less, but it is not clear if this is because the manufacturer is ''loosing their touch,'' or because tubes cannot be effectively rebuilt after a certain number of times. Taking into account the expected tube lifetimes, the statistical fluctuations on this number, and the amount of time it takes for the manufacturer to make good tubes, we require about 14 tubes either operating, ready as good spares or being manufactured, in order to have sufficient spares to run the Linac. As a hedge against supplier drop out, we need to increase our inventory of good spare tubes by about three tubes per year for the next few years.

  6. Measurement of the $B^-$ lifetime using a simulation free approach for trigger bias correction

    SciTech Connect (OSTI)

    Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.; Apresyan, A.

    2010-04-01

    The collection of a large number of B hadron decays to hadronic final states at the CDF II detector is possible due to the presence of a trigger that selects events based on track impact parameters. However, the nature of the selection requirements of the trigger introduces a large bias in the observed proper decay time distribution. A lifetime measurement must correct for this bias and the conventional approach has been to use a Monte Carlo simulation. The leading sources of systematic uncertainty in the conventional approach are due to differences between the data and the Monte Carlo simulation. In this paper they present an analytic method for bias correction without using simulation, thereby removing any uncertainty between data and simulation. This method is presented in the form of a measurement of the lifetime of the B{sup -} using the mode B{sup -} {yields} D{sup 0}{pi}{sup -}. The B{sup -} lifetime is measured as {tau}{sub B{sup -}} = 1.663 {+-} 0.023 {+-} 0.015 ps, where the first uncertainty is statistical and the second systematic. This new method results in a smaller systematic uncertainty in comparison to methods that use simulation to correct for the trigger bias.

  7. Measurement of the B-cmeson lifetime in the decay B-c?J/???

    SciTech Connect (OSTI)

    Aaltonen, T.; lvarez Gonzlez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bisello, D.; Bizjak, I.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Calamba, A.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chung, W. H.; Chung, Y. S.; Ciocci, M. A.; Clark, A.; Clarke, C.; Compostella, G.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuevas, J.; Culbertson, R.; Dagenhart, D.; dAscenzo, N.; Datta, M.; de Barbaro, P.; DellOrso, M.; Demortier, L.; Deninno, M.; Devoto, F.; dErrico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; DOnofrio, M.; Donati, S.; Dong, P.; Dorigo, M.; Dorigo, T.; Ebina, K.; Elagin, A.; Eppig, A.; Erbacher, R.; Errede, S.; Ershaidat, N.; Eusebi, R.; Farrington, S.; Feindt, M.; Fernandez, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Funakoshi, Y.; Furic, I.; Gallinaro, M.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; Gonzlez, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Halkiadakis, E.; Hamaguchi, A.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harr, R. F.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Hewamanage, S.; Hocker, A.; Hopkins, W.; Horn, D.; Hou, S.; Hughes, R. E.; Hurwitz, M.; Husemann, U.; Hussain, N.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kim, Y. J.; Kimura, N.; Kirby, M.; Klimenko, S.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Kruse, M.; Krutelyov, V.; Kuhr, T.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; LeCompte, T.; Lee, E.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lin, C.-J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maeshima, K.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Martnez, M.; Mastrandrea, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Mondragon, M. N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Neubauer, M. S.; Nielsen, J.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagan Griso, S.; Pagliarone, C.; Palencia, E.; Papadimitriou, V.; Paramonov, A. A.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.; Sakumoto, W. K.

    2013-01-01

    The lifetime of the B-c meson is measured using 272 exclusive B-c?J/?(?????)?? decays reconstructed in data from proton-antiproton collisions corresponding to an integrated luminosity of 6.7 fb? recorded by the CDF II detector at the Fermilab Tevatron. The lifetime of the B-cmeson is measured to be ?(B-c)=0.4520.048(stat)0.027(syst) ps. This is the first measurement of the B-c meson lifetime in a fully reconstructed hadronic channel, and it agrees with previous results and has comparable precision.

  8. Demonstration of long minority carrier lifetimes in very narrow bandgap ternary InAs/GaInSb superlattices

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Olson, Benjamin Varberg; Kim, Jin K.; Kadlec, Emil Andrew; Shaner, Eric A.; Haugan, Heather J.; Brown, Gail J.

    2015-09-28

    Minority carrier lifetimes in very long wavelength infrared (VLWIR) InAs/GaInSb superlattices (SLs) are reported using time-resolved microwave reflectance measurements. A strain-balanced ternary SL absorber layer of 47.0 Å InAs/21.5 Å Ga0.75In0.25Sb, corresponding to a bandgap of ~50 meV, is found to have a minority carrier lifetime of 140 ± 20 ns at ~18 K. This lifetime is extraordinarily long, when compared to lifetime values previously reported for other VLWIR SL detector materials. As a result, this enhancement is attributed to the strain-engineered ternary design, which offers a variety of epitaxial advantages and ultimately leads to a reduction of defect-mediated recombinationmore » centers.« less

  9. Demonstration of long minority carrier lifetimes in very narrow bandgap ternary InAs/GaInSb superlattices

    SciTech Connect (OSTI)

    Olson, Benjamin Varberg; Kim, Jin K.; Kadlec, Emil Andrew; Shaner, Eric A.; Haugan, Heather J.; Brown, Gail J.

    2015-09-28

    Minority carrier lifetimes in very long wavelength infrared (VLWIR) InAs/GaInSb superlattices (SLs) are reported using time-resolved microwave reflectance measurements. A strain-balanced ternary SL absorber layer of 47.0 Å InAs/21.5 Å Ga0.75In0.25Sb, corresponding to a bandgap of ~50 meV, is found to have a minority carrier lifetime of 140 ± 20 ns at ~18 K. This lifetime is extraordinarily long, when compared to lifetime values previously reported for other VLWIR SL detector materials. As a result, this enhancement is attributed to the strain-engineered ternary design, which offers a variety of epitaxial advantages and ultimately leads to a reduction of defect-mediated recombination centers.

  10. Accurate potential energy, dipole moment curves, and lifetimes of vibrational states of heteronuclear alkali dimers

    SciTech Connect (OSTI)

    Fedorov, Dmitry A.; Varganov, Sergey A.; Derevianko, Andrei

    2014-05-14

    We calculate the potential energy curves, the permanent dipole moment curves, and the lifetimes of the ground and excited vibrational states of the heteronuclear alkali dimers XY (X, Y = Li, Na, K, Rb, Cs) in the X{sup 1}?{sup +} electronic state using the coupled cluster with singles doubles and triples method. All-electron quadruple-? basis sets with additional core functions are used for Li and Na, and small-core relativistic effective core potentials with quadruple-? quality basis sets are used for K, Rb, and Cs. The inclusion of the coupled cluster non-perturbative triple excitations is shown to be crucial for obtaining the accurate potential energy curves. A large one-electron basis set with additional core functions is needed for the accurate prediction of permanent dipole moments. The dissociation energies are overestimated by only 14 cm{sup ?1} for LiNa and by no more than 114 cm{sup ?1} for the other molecules. The discrepancies between the experimental and calculated harmonic vibrational frequencies are less than 1.7 cm{sup ?1}, and the discrepancies for the anharmonic correction are less than 0.1 cm{sup ?1}. We show that correlation between atomic electronegativity differences and permanent dipole moment of heteronuclear alkali dimers is not perfect. To obtain the vibrational energies and wave functions the vibrational Schrdinger equation is solved with the B-spline basis set method. The transition dipole moments between all vibrational states, the Einstein coefficients, and the lifetimes of the vibrational states are calculated. We analyze the decay rates of the vibrational states in terms of spontaneous emission, and stimulated emission and absorption induced by black body radiation. In all studied heteronuclear alkali dimers the ground vibrational states have much longer lifetimes than any excited states.

  11. Intrinsic state lifetimes in {sup 103}Pd and {sup 106,107}Cd

    SciTech Connect (OSTI)

    Ashley, S. F.; Thomas, N. J.; Regan, P. H.; Gelletly, W.; Andgren, K.; McCutchan, E. A.; Casten, R. F.; Plettner, C.; Vinson, J.; Werner, V.; Williams, E.; Zamfir, N. V.; Amon, L.; Cakirli, R. B.; Clark, R. M.; Guerdal, G.; Keyes, K. L.; Papenberg, A.; Meyer, D. A.; Erduran, M. N.

    2007-12-15

    The mean-lifetimes, {tau}, of various medium-spin excited states in {sup 103}Pd and {sup 106,107}Cd have been deduced using the Recoil Distance Doppler Shift technique and the Differential Decay Curve Method. In {sup 106}Cd, the mean-lifetimes of the I{sup {pi}}=12{sup +} state at E{sub x}=5418 keV and the I{sup {pi}}=11{sup -} state at E{sub x}=4324 keV have been deduced as 11.4(17)ps and 8.2(7)ps, respectively. The associated {beta}{sub 2} deformation within the axially-symmetric deformed rotor model for these states are 0.14(1) and 0.14(1), respectively. The {beta}{sub 2} deformation of 0.14(1) for the I{sup {pi}}=12{sup +} state in {sup 106}Cd compares with a predicted {beta}{sub 2} value from total Routhian surface (TRS) calculations of 0.17. In addition, the mean-lifetimes of the yrast I{sup {pi}}=(15/2){sup -} states in {sup 103}Pd (at E{sub x}=1262 keV) and {sup 107}Cd (at E{sub x}=1360 keV) have been deduced to be 31.2(44)ps and 31.4(17)ps, respectively, corresponding to {beta}{sub 2} values of 0.16(1) and 0.12(1) assuming axial symmetry. Agreement with TRS calculations are good for {sup 103}Pd but deviate for that predicted for {sup 107}Cd.

  12. Temperature dependence of diffusion length, lifetime and minority electron mobility in GaInP

    SciTech Connect (OSTI)

    Schultes, F. J.; Haegel, N. M.; Christian, T.; Alberi, K.; Fluegel, B.; Jones-Albertus, R.; Pickett, E.; Liu, T.; Misra, P.; Sukiasyan, A.; Yuen, H.

    2013-12-09

    The mobility of electrons in double heterostructures of p-type Ga{sub 0.50}In{sub 0.50}P has been determined by measuring minority carrier diffusion length and lifetime. The minority electron mobility increases monotonically from 300?K to 5?K, limited primarily by optical phonon and alloy scattering. Comparison to majority electron mobility over the same temperature range in comparably doped samples shows a significant reduction in ionized impurity scattering at lower temperatures, due to differences in interaction of repulsive versus attractive carriers with ionized dopant sites. These results should be useful in modeling and optimization for multi-junction solar cells and other optoelectronic devices.

  13. Photo-degradation of Lexan polycarbonate studied using positron lifetime spectroscopy

    SciTech Connect (OSTI)

    Hareesh, K.; Sanjeev, Ganesh; Pandey, A. K.; Meghala, D.; Ranganathaiah, C.

    2013-02-05

    The free volume properties of pristine and UV irradiated Lexan polycarbonate have been investigated using Positron Lifetime Spectroscopy (PLS). The decrease in o-Ps life time and free volume size of irradiated sample is attributed to free volume modification and formation of more stable free radicals. These free radicals are formed due to the breakage of C-O bonds in Lexan polycarbonate after irradiation. This is also supported by the decrease in the intensity of C-O bond after exposure to UV-radiation as studied from Fourier Transform Infrared (FTIR) spectroscopy and it also shows that benzene ring does not undergo any changes after irradiation.

  14. Origin of the Anomalous Long Lifetime of 14C | Argonne Leadership Computing

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Facility Origin of the Anomalous Long Lifetime of 14C Authors: Maris, P., Vary, J.P., Navratil, P., Ormand, W.E., Nam, H., Dean, D.J. We report the microscopic origins of the anomalously suppressed beta decay of 14C to 14N using the ab initio no-core shell model with the Hamiltonian from the chiral effective field theory including three-nucleon force terms. The three-nucleon force induces unexpectedly large cancellations within the p shell between contributions to beta decay, which reduce

  15. Measurement of the B+- lifetime and top quark identification using secondary vertex b-tagging

    SciTech Connect (OSTI)

    Schwartzman, Ariel G

    2004-02-01

    This dissertation presents a preliminary measurement of the B{sup {+-}} lifetime through the full reconstruction of its decay chain, and the identification of top quark production in the electron plus jets channel using the displaced vertex b-tagging method. Its main contribution is the development, implementation and optimization of the Kalman filter algorithm for vertex reconstruction, and of the displaced vertex technique for tagging jets arising from b quark fragmentation, both of which have now become part of the standard D0 reconstruction package. These two algorithms fully exploit the new state-of-the-art tracking detectors, recently installed as part of the Run 2 D0 upgrade project. The analysis is based on data collected during Run 2a at the Fermilab Tevatron p{bar p} Hadron Collider up to April 2003, corresponding to an integrated luminosity of 60 pb{sup -1}. The measured B meson lifetime of {tau} = 1.57 {+-} 0.18 ps is in agreement with the current world average, with a competitive level of precision expected when the full data sample becomes available.

  16. Work at FNAL to achieve long electron drift lifetime in liquid argon

    SciTech Connect (OSTI)

    Finley, D.; Jaskierny, W.; Kendziora, C.; Krider, J.; Pordes, S.; Rapidis, P.A.; Tope, T.; /Fermilab

    2006-10-01

    This note records some of the work done between July 2005 and July 2006 to achieve long (many milliseconds) electron drift lifetimes in liquid argon at Fermilab. The work is part of a process to develop some experience at Fermilab with the technology required to construct a large liquid argon TPC. This technology has been largely developed by the ICARUS collaboration in Europe and this process can be seen as technology transfer. The capability to produce liquid argon in which electrons have drift lifetimes of several milliseconds is crucial to a successful device. Liquid argon calorimeters have been successfully operated at Fermilab; their electro-negative contaminants are at the level of 10{sup -7} while the TPC we are considering requires a contamination level at the level of 10{sup -11}, tens of parts per trillion (ppt). As well as demonstrating the ability to produce liquid argon at this level of purity, the work is part of a program to test the effect on the electron drift time of candidate materials for the construction of a TPC in liquid argon.

  17. Insulation materials for commercial buildings in North America: An assessment of lifetime energy and environmental impacts

    SciTech Connect (OSTI)

    Biswas, Kaushik; Shrestha, Som S.; Bhandari, Mahabir S.; Desjarlais, Andre Omer

    2015-12-12

    In the United States, commercial buildings accounted for about 19 percent of the total primary energy consumption in 2012. Further, 29 percent of the site energy in commercial buildings was consumed for space heating and cooling. Applying insulation materials to building envelopes is an effective way of reducing energy consumption for heating and cooling, and limiting the negative environmental impacts from the buildings sector. While insulation materials have a net positive impact on the environment due to reduced energy consumption, they also have some negative impacts associated with their 'embodied energy'. The total lifetime environmental impacts of insulation materials are a summation of: (1) direct impacts due to their embodied energy, and (2) indirect or impacts avoided due to the reduced building energy consumption. Here, assessments of the lifetime environmental impacts of selected insulation materials are presented. Direct and indirect environmental impact factors were estimated for the cradle-to-grave insulation life cycle stages. Impact factors were calculated for two categories: primary energy consumption and global warming potential. The direct impact factors were calculated using data from existing literature and a life cycle assessment software. The indirect impact factors were calculated through simulations of a set of standard whole-building models.

  18. Recoil Distance Method Lifetime Measurements in 107Cd and 103Pd

    SciTech Connect (OSTI)

    Andgren, K.; Ashley, S. F.; Regan, P. H.; McCutchan, E. A.; Zamfir, N. V.; Casten, R. F.; Meyer, D. A.; Plettner, C.; Vinson, J.; Werner, V.; Williams, E.; Amon, L.; Cakirli, R. B.; Erduran, M. N.; Clark, R. M.; Guerdal, G.; Keyes, K. L.; Papenberg, A.; Pietralla, N.; Rainovski, G.

    2006-04-26

    Preliminary lifetime values have been measured for a number of near-yrast states in the odd-A transitional nuclei 107Cd and 103Pd. The reaction used to populate the nuclei of interest was 98Mo(12C,3nx{alpha})107Cd, 103Pd, with the beam delivered by the tandem accelerator of the Wright Nuclear Structure Laboratory at an incident beam energy of 60 MeV. Our experiment was aimed at the investigation of collective excitations built on the unnatural parity, {nu} h11/2 orbital, specifically by measuring the B(E2) values of decays from the excited levels built on this intrinsic structure, using the Doppler Recoil Distance Method. We report lifetimes and associated transition probabilities for decays from the 15/2- and the 19/2- states in 107Cd and the first measurement of the 15/2- state in 103Pd. These results suggest that neither a simple rotational or vibrational interpretation is sufficient to explain the observed structures.

  19. Degradation Mechanisms and Lifetime Prediction for Lithium-Ion Batteries -- A Control Perspective: Preprint

    SciTech Connect (OSTI)

    Smith, Kandler; Shi, Ying; Santhanagopalan, Shriram

    2015-07-29

    Predictive models of Li-ion battery lifetime must consider a multiplicity of electrochemical, thermal, and mechanical degradation modes experienced by batteries in application environments. To complicate matters, Li-ion batteries can experience different degradation trajectories that depend on storage and cycling history of the application environment. Rates of degradation are controlled by factors such as temperature history, electrochemical operating window, and charge/discharge rate. We present a generalized battery life prognostic model framework for battery systems design and control. The model framework consists of trial functions that are statistically regressed to Li-ion cell life datasets wherein the cells have been aged under different levels of stress. Degradation mechanisms and rate laws dependent on temperature, storage, and cycling condition are regressed to the data, with multiple model hypotheses evaluated and the best model down-selected based on statistics. The resulting life prognostic model, implemented in state variable form, is extensible to arbitrary real-world scenarios. The model is applicable in real-time control algorithms to maximize battery life and performance. We discuss efforts to reduce lifetime prediction error and accommodate its inevitable impact in controller design.

  20. Insulation materials for commercial buildings in North America: An assessment of lifetime energy and environmental impacts

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Biswas, Kaushik; Shrestha, Som S.; Bhandari, Mahabir S.; Desjarlais, Andre Omer

    2015-12-12

    In the United States, commercial buildings accounted for about 19 percent of the total primary energy consumption in 2012. Further, 29 percent of the site energy in commercial buildings was consumed for space heating and cooling. Applying insulation materials to building envelopes is an effective way of reducing energy consumption for heating and cooling, and limiting the negative environmental impacts from the buildings sector. While insulation materials have a net positive impact on the environment due to reduced energy consumption, they also have some negative impacts associated with their 'embodied energy'. The total lifetime environmental impacts of insulation materials aremore » a summation of: (1) direct impacts due to their embodied energy, and (2) indirect or impacts avoided due to the reduced building energy consumption. Here, assessments of the lifetime environmental impacts of selected insulation materials are presented. Direct and indirect environmental impact factors were estimated for the cradle-to-grave insulation life cycle stages. Impact factors were calculated for two categories: primary energy consumption and global warming potential. The direct impact factors were calculated using data from existing literature and a life cycle assessment software. The indirect impact factors were calculated through simulations of a set of standard whole-building models.« less

  1. Stochastic Boundary, Diffusion, Emittance Growth and Lifetime calculation for the RHIC e-lens

    SciTech Connect (OSTI)

    Abreu,N.P.; Fischer, W.; Luo, Y.; Robert-Demolaize, G.

    2009-01-20

    To compensate the large tune shift and tune spread generated by the head-on beam-beam interactions in polarized proton operation in the Relativistic Heavy Ion Collider (RHIC), a low energy electron beam with proper Gaussian transverse profiles was proposed to collide head-on with the proton beam. In this article, using a modified version of SixTrack [1], we investigate stability of the single particle in the presence of head-on beam-beam compensation. The Lyapunov exponent and action diffusion are calculated and compared between the cases without and with beam-beam compensation for two different working points and various bunch intensities. Using the action diffusion results the emittance growth rate and lifetime of the proton beam is also estimated for the different scenarios.

  2. Touschek Background and Lifetime Studies for the SuperB Factory

    SciTech Connect (OSTI)

    Boscolo, M.; Biagini, M.; Raimondi, P.; Sullivan, M.; Paoloni, E.; /INFN, Pisa

    2010-08-26

    The novel crab waist collision scheme under test at the DA{Phi}NE Frascati {Phi}-factory finds its natural application to the SuperB project, the asymmetric e{sup +}e{sup -} flavour factory at very high luminosity with relatively low beam currents and reduced backgrounds. The SuperB accelerator design requires a careful choice of beam parameters to reach a good trade-off between different effects. We present here simulation results for the Touschek backgrounds and lifetime obtained for both the low and high energy rings for different machine designs. A first set of horizontal collimators has been studied to stop Touschek particles. A study of the distributions of the Touschek particle losses at the interaction region into the detectors for further investigations is underway.

  3. Combined results on b-hadron production rates, lifetimes, oscillations and semileptonic decays

    SciTech Connect (OSTI)

    WIllocq, stephane

    2000-08-02

    Combined results on b-hadron lifetimes, b-hadron production rates B{sub d}{sup 0}--Anti-B{sub d}{sup 0} and B{sub s}{sup 0}--Anti-B{sub s}{sup 0} oscillations, the decay width difference between the mass eigenstates of the B{sub s}{sup 0}--Anti-B{sub s}{sup 0} system, and the values of the CKM matrix elements {vert_bar}V{sub cb}{vert_bar} and {vert_bar}V{sub ub}{vert_bar} are obtained from published and preliminary measurements available in Summer 99 from the ALEPH, CDF, DELPHI, L3, OPAL and SLD Collaborations.

  4. Elastic scattering by hot electrons and apparent lifetime of longitudinal optical phonons in gallium nitride

    SciTech Connect (OSTI)

    Khurgin, Jacob B.; Bajaj, Sanyam; Rajan, Siddharth

    2015-12-28

    Longitudinal optical (LO) phonons in GaN generated in the channel of high electron mobility transistors (HEMT) are shown to undergo nearly elastic scattering via collisions with hot electrons. The net result of these collisions is the diffusion of LO phonons in the Brillouin zone causing reduction of phonon and electron temperatures. This previously unexplored diffusion mechanism explicates how an increase in electron density causes reduction of the apparent lifetime of LO phonons, obtained from the time resolved Raman studies and microwave noise measurements, while the actual decay rate of the LO phonons remains unaffected by the carrier density. Therefore, the saturation velocity in GaN HEMT steadily declines with increased carrier density, in a qualitative agreement with experimental results.

  5. Improved Measurement of the Positive-Muon Lifetime and Determination of the Fermi Constant

    SciTech Connect (OSTI)

    Chitwood, D. B.; Clayton, S. M.; Crnkovic, J.; Debevec, P. T.; Hertzog, D. W.; Kammel, P.; Kiburg, B.; Kunkle, J.; McNabb, R.; Mulhauser, F.; Oezben, C. S.; Polly, C. C.; Webber, D. M.; Winter, P.; Banks, T. I.; Crowe, K. M.; Lauss, B.; Barnes, M. J.; Wait, G. D.; Battu, S.

    2007-07-20

    The mean life of the positive muon has been measured to a precision of 11 ppm using a low-energy, pulsed muon beam stopped in a ferromagnetic target, which was surrounded by a scintillator detector array. The result, {tau}{sub {mu}}=2.197 013(24) {mu}s, is in excellent agreement with the previous world average. The new world average {tau}{sub {mu}}=2.197 019(21) {mu}s determines the Fermi constant G{sub F}=1.166 371(6)x10{sup -5} GeV{sup -2} (5 ppm). Additionally, the precision measurement of the positive-muon lifetime is needed to determine the nucleon pseudoscalar coupling g{sub P}.

  6. Lifetime measurements of yrast states in {sup 162}Yb and {sup 166}Hf

    SciTech Connect (OSTI)

    McCutchan, E.A.; Casten, R.F.; Ai, H.; Amro, H.; Heinz, A.; Meyer, D.A.; Plettner, C.; Qian, J.; Ressler, J.J.; Werner, V.; Williams, E.; Winkler, R.; Zamfir, N.V.; Babilon, M.; Brenner, D.S.; Guerdal, G.; Hughes, R.O.; Thomas, N.J.

    2006-03-15

    Lifetime measurements of yrast levels in {sup 162}Yb and {sup 166}Hf were performed using the recoil distance Doppler-shift method in coincidence mode. Excited states in {sup 162}Yb and {sup 166}Hf were populated via the reactions {sup 116}Cd({sup 50}Ti, 4n) and {sup 122}Sn({sup 48}Ti, 4n), respectively. The resulting B(E2) values are compared with the X(5) critical point model predictions and interacting boson approximation (IBA) model calculations. The X(5) model provides a reasonable description of the yrast B(E2) values in {sup 166}Hf, whereas the IBA fails to reproduce the transition strengths from the higher spin levels. In {sup 162}Yb, some transitions agree with the X(5) predictions while others are more consistent with the predictions of the IBA or a deformed symmetric rotor.

  7. Lifetime improvement of sheathed thermocouples for use in high-temperature and thermal transient operations

    SciTech Connect (OSTI)

    McCulloch, R.W.; Clift, J.H.

    1982-01-01

    Premature failure of small-diameter, magnesium-oxide-insulated sheathed thermocouples occurred when they were placed within nuclear fuel rod simulators (FRSs) to measure high temperatures and to follow severe thermal transients encountered during simulation of nuclear reactor accidents in Oak Ridge National Laboratory (ORNL) thermal-hydraulic test facilities. Investigation of thermally cycled thermocouples yielded three criteria for improvement of thermocouple lifetime: (1) reduction of oxygen impurities prior to and during their fabrication, (2) refinement of thermoelement grain size during their fabrication, and (3) elimination of prestrain prior to use above their recrystallization temperature. The first and third criteria were satisfied by improved techniques of thermocouple assembly and by a recovery anneal prior to thermocouple use.

  8. Study of behavior and determination of customer lifetime value(CLV) using Markov chain model

    SciTech Connect (OSTI)

    Permana, Dony; Indratno, Sapto Wahyu; Pasaribu, Udjianna S.

    2014-03-24

    Customer Lifetime Value or CLV is a restriction on interactive marketing to help a company in arranging financial for the marketing of new customer acquisition and customer retention. Additionally CLV can be able to segment customers for financial arrangements. Stochastic models for the fairly new CLV used a Markov chain. In this model customer retention probability and new customer acquisition probability play an important role. This model is originally introduced by Pfeifer and Carraway in 2000 [1]. They introduced several CLV models, one of them only involves customer and former customer. In this paper we expand the model by adding the assumption of the transition from former customer to customer. In the proposed model, the CLV value is higher than the CLV value obtained by Pfeifer and Caraway model. But our model still requires a longer convergence time.

  9. PREDICTION OF DISSOLVER LIFETIMES THROUGH NON-DESTRUCTIVE EVALUATION AND LABORATORY TESTING

    SciTech Connect (OSTI)

    Mickalonis, J.; Woodsmall, T.; Hinz, W.; Edwards, T.

    2011-10-03

    Non-destructive evaluation was used as the primary method of monitoring the corrosion degradation of nuclear material dissolvers and assessing the remaining lifetimes. Materials were typically processed in nitric acid based (4-14M) solutions containing fluoride concentrations less than 0.2 M. The primary corrosion issue for the stainless steel dissolvers is the occurrence of localized corrosion near the tank bottom and the heat affected zones of the welds. Laboratory data for a range of operational conditions, including solution chemistry and temperature, was used to assess the impact of processing changes on the dissolver corrosion rate. Experimental and NDE-based general corrosion rates were found to be in reasonable agreement for standard dissolution chemistries consisting of nitric acid with fluorides and at temperatures less than 95 C. Greater differences were observed when chloride was present as an impurity and temperatures exceeded 100 C.

  10. CONSTRAINTS ON THE LIFETIMES OF DISKS RESULTING FROM TIDALLY DESTROYED ROCKY PLANETARY BODIES

    SciTech Connect (OSTI)

    Girven, J.; Gaensicke, B. T.; Marsh, T. R.; Brinkworth, C. S.; Hoard, D. W.; Farihi, J.; Koester, D.

    2012-04-20

    Spitzer IRAC observations of 15 metal-polluted white dwarfs reveal infrared excesses in the spectral energy distributions of HE 0110-5630, GD 61, and HE 1349-2305. All three of these stars have helium-dominated atmospheres, and their infrared emissions are consistent with warm dust produced by the tidal destruction of (minor) planetary bodies. This study brings the number of metal-polluted, helium and hydrogen atmosphere white dwarfs surveyed with IRAC to 53 and 38, respectively. It also nearly doubles the number of metal-polluted helium-rich white dwarfs found to have closely orbiting dust by Spitzer. From the increased statistics for both atmospheric types with circumstellar dust, we derive a typical disk lifetime of log [t{sub disk}(yr)] = 5.6 {+-} 1.1 (ranging from 3 Multiplication-Sign 10{sup 4} to 5 Multiplication-Sign 10{sup 6} yr). This assumes a relatively constant rate of accretion over the timescale where dust persists, which is uncertain. We find that the fraction of highly metal-polluted helium-rich white dwarfs that have an infrared excess detected by Spitzer is only 23%, compared to 48% for metal-polluted hydrogen-rich white dwarfs, and we conclude from this difference that the typical lifetime of dusty disks is somewhat shorter than the diffusion timescales of helium-rich white dwarf. We also find evidence for higher time-averaged accretion rates onto helium-rich stars compared to the instantaneous accretion rates onto hydrogen-rich stars; this is an indication that our picture of evolved star-planetary system interactions is incomplete. We discuss some speculative scenarios that can explain the observations.

  11. Development of high performance refractory fibers with enhanced insulating properties and longer service lifetimes

    SciTech Connect (OSTI)

    Martin, P.C.; DePoorter, G.L.; Munoz, D.R.

    1991-02-01

    We have initiated a three phase investigation of the development of high performance refractory fibers with enhanced insulating properties and longer usable lifetimes. This report presents the results of the first phase of the study, performed from Aug. 1989 through Feb. 1991, which shows that significant energy saving are possible through the use of high temperature insulating fibers that better retain their efficient insulating properties during the service lifetime of the fibers. The remaining phases of this program include the pilot scale development and then full scale production feasibility development and evaluation of enhanced high temperature refractory insulting fibers. This first proof of principle phase of the program presents a summary of the current use patterns of refractory fibers, a laboratory evaluation of the high temperature performance characteristics of selected typical refractory fibers and an analysis of the potential energy savings through the use of enhanced refractory fibers. The current use patterns of refractory fibers span a wide range of industries and high temperature furnaces within those industries. The majority of high temperature fiber applications are in furnaces operating between 2000 and 26000{degrees}F. The fibers used in furnaces operating within this range provide attractive thermal resistance and low thermal storage at reasonable cost. A series of heat treatment studies performed for this phase of the program has shown that the refractory fibers, as initially manufactured, have attractive thermal conductivities for high temperature applications but the fibers go through rapid devitrification and subsequent crystal growth upon high temperature exposure. Development of improved fibers, maintaining the favorable characteristics of the existing as-manufactured fibers, could save between 1 and 4% of the energy consumed in high temperature furnaces using refractory fibers.

  12. An overview of the United States Department of Energy plant lifetime improvement program

    SciTech Connect (OSTI)

    Rosinski, S.T.; Clauss, J.M.; Harrison, D.L.

    1993-08-01

    Today, 109 nuclear power plants provide over 20 percent of the electrical energy generated in the US. The operating license of the first of these plants will expire in the year 2000; one third of the operating licenses will expire by 2010 and the remaining plant licenses are scheduled to expire by 2033. The National Energy Strategy assumes that 70 percent of these plants will continue to operate beyond their current license expiration to assist in ensuring an adequate, diverse, and environmentally acceptable energy supply for economic growth. In order to preserve this energy resource in the US three major tasks must be successfully completed: (1) establishment of the regulations, technical standards, and procedures for the preparation and review of a license renewal application; (2) development, verification, and validation of the various technical criteria and bases for needed monitoring, refurbishment, or replacement of plant equipment; and (3) demonstration of the regulatory process. Since 1985, the US Department of Energy (DOE) has been working with the nuclear industry and the US Nuclear Regulatory Commission (NRC) to establish and demonstrate the option to extend the life of nuclear power plants through the renewal of operating licenses. This paper focuses primarily on DOE`s Plant Lifetime Improvement (PLIM) Program efforts to develop the technical criteria and bases for effective aging management and lifetime improvement for continued operation of nuclear power plants. This paper describes current projects to resolve generic technical issues, including degradation of long-lived components, reactor pressure vessel (RPV) embrittlement management approaches, and analytical methodologies to characterize RPV integrity.

  13. Progress on Establishing Guidelines for National Ignition Facility (NIF) Experiments to Extend Debris Shield Lifetime

    SciTech Connect (OSTI)

    Tobin, M; Eder, D; Braun, D; MacGowan, B

    2000-07-26

    The survivability and performance of the debris shields on the National Ignition Facility (NIF) are a key factor for the successful conduct and affordable operation of the facility. The improvements required over Nova debris shields are described. Estimates of debris shield lifetimes in the presence of target emissions with 4 - 5 J/cm{sup 2} laser fluences (and higher) indicate lifetimes that may contribute unacceptably to operations costs for NIF. We are developing detailed guidance for target and experiment designers for NIF to assist in minimizing the damage to, and therefore the cost of, maintaining NIF debris shields. The guidance limits the target mass that is allowed to become particulate on the debris shields (300 mg). It also limits the amount of material that can become shrapnel for any given shot (10 mg). Finally, it restricts the introduction of non-volatile residue (NVR) that is a threat to the sol-gel coatings on the debris shields to ensure that the chamber loading at any time is less than 1 pg/cm{sup 2}. We review the experimentation on the Nova chamber that included measuring quantities of particulate on debris shields by element and capturing shrapnel pieces in aerogel samples mounted in the chamber. We also describe computations of x-ray emissions from a likely NIF target and the associated ablation expected from this x-ray exposure on supporting target hardware. We describe progress in assessing the benefits of a pre-shield and the possible impact on the guidance for target experiments on NIF. Plans for possible experimentation on Omega and other facilities to improve our understanding of target emissions and their impacts are discussed. Our discussion of planned future work provides a forum to invite possible collaboration with the IFE community.

  14. Collision lifetimes of polyatomic molecules at low temperatures: Benzenebenzene vs benzenerare gas atom collisions

    SciTech Connect (OSTI)

    Cui, Jie; Krems, Roman V.; Li, Zhiying

    2014-10-28

    We use classical trajectory calculations to study the effects of the interaction strength and the geometry of rigid polyatomic molecules on the formation of long-lived collision complexes at low collision energies. We first compare the results of the calculations for collisions of benzene molecules with rare gas atoms He, Ne, Ar, Kr, and Xe. The comparison illustrates that the mean lifetimes of the collision complexes increase monotonically with the strength of the atommolecule interaction. We then compare the results of the atombenzene calculations with those for benzenebenzene collisions. The comparison illustrates that the mean lifetimes of the benzenebenzene collision complexes are significantly reduced due to non-ergodic effects prohibiting the molecules from sampling the entire configuration space. We find that the thermally averaged lifetimes of the benzenebenzene collisions are much shorter than those for Xe with benzene and similar to those for Ne with benzene.

  15. Measurement of the B-cmeson lifetime in the decay B-c→J/ψπ⁻

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; et al

    2013-01-02

    The lifetime of the B-c meson is measured using 272 exclusive B-c→J/ψ(→μ⁺μ⁻)π⁻ decays reconstructed in data from proton-antiproton collisions corresponding to an integrated luminosity of 6.7 fb⁻¹ recorded by the CDF II detector at the Fermilab Tevatron. The lifetime of the B-cmeson is measured to be τ(B-c)=0.452±0.048(stat)±0.027(syst) ps. This is the first measurement of the B-c meson lifetime in a fully reconstructed hadronic channel, and it agrees with previous results and has comparable precision.

  16. Enhancement of minority carrier lifetime of GaInP with lateral composition modulation structure grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Park, K. W.; Ravindran, Sooraj; Kang, S. J.; Hwang, H. Y.; Jho, Y. D.; Park, C. Y.; Jo, Y. R.; Kim, B. J.; Lee, Y. T.

    2014-07-28

    We report the enhancement of the minority carrier lifetime of GaInP with a lateral composition modulated (LCM) structure grown using molecular beam epitaxy (MBE). The structural and optical properties of the grown samples are studied by transmission electron microscopy and photoluminescence, which reveal the formation of vertically aligned bright and dark slabs corresponding to Ga-rich and In-rich GaInP regions, respectively, with good crystal quality. With the decrease of V/III ratio during LCM GaInP growth, it is seen that the band gap of LCM GaInP is reduced, while the PL intensity remains high and is comparable to that of bulk GaInP. We also investigate the minority carrier lifetime of LCM structures made with different flux ratios. It is found that the minority carrier lifetime of LCM GaInP is ?37 times larger than that of bulk GaInP material, due to the spatial separation of electrons and holes by In-rich and Ga-rich regions of the LCM GaInP, respectively. We further demonstrate that the minority carrier lifetime of the grown LCM GaInP structures can easily be tuned by simply adjusting the V/III flux ratio during MBE growth, providing a simple yet powerful technique to tailor the electrical and optical properties at will. The exceptionally high carrier lifetime and the reduced band gap of LCM GaInP make them a highly attractive candidate for forming the top cell of multi-junction solar cells and can enhance their efficiency, and also make them suitable for other optoelectronics devices, such as photodetectors, where longer carrier lifetime is beneficial.

  17. Evaluation of Lifetime of High Efficiency Organic Photovoltaic Devices: Cooperative Research and Development Final Report, CRADA Number CRD-10-379

    SciTech Connect (OSTI)

    Olson, D.

    2013-04-01

    As a part of this joint work, Solarmer and NREL will investigate the lifetime and stability of Organic Photovoltaic Devices based on Solarmer high efficiency active layer materials.

  18. Lifetime and Polarization of the Radiative Decay of Excitons, Biexcitons, and Trions in CdSe Nanocrystal Quantum Dots

    SciTech Connect (OSTI)

    Califano, M.; Franceschetti, A.; Zunger, A.

    2007-01-01

    Using the pseudopotential configuration-interaction method, we calculate the intrinsic lifetime and polarization of the radiative decay of single excitons (X), positive and negative trions (X{sup +} and X{sup -}), and biexcitons (XX) in CdSe nanocrystal quantum dots. We investigate the effects of the inclusion of increasingly more complex many-body treatments, starting from the single-particle approach and culminating with the configuration-interaction scheme. Our configuration-interaction results for the size dependence of the single-exciton radiative lifetime at room temperature are in excellent agreement with recent experimental data. We also find the following. (i) Whereas the polarization of the bright exciton emission is always perpendicular to the hexagonal c axis, the polarization of the dark exciton switches from perpendicular to parallel to the hexagonal c axis in large dots, in agreement with experiment. (ii) The ratio of the radiative lifetimes of mono- and biexcitons (X):(XX) is {approx}1:1 in large dots (R=19.2 {angstrom}). This ratio increases with decreasing nanocrystal size, approaching 2 in small dots (R=10.3 {angstrom}). (iii) The calculated ratio (X{sup +}):(X{sup -}) between positive and negative trion lifetimes is close to 2 for all dot sizes considered.

  19. Measurement of the Lambda(b) lifetime in the exclusive decay Lambda(b) ---> J / psi Lambda

    SciTech Connect (OSTI)

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Aguilo, E.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; /Buenos Aires U. /Rio de Janeiro, CBPF /Rio de Janeiro State U. /Sao Paulo, IFT /Alberta U. /Simon Fraser U. /York U., Canada /McGill U. /Hefei, CUST /Andes U., Bogota /Charles U.

    2007-04-01

    We have measured the {lambda}{sub b} lifetime using the exclusive decay {lambda}{sub b}{yields}J/{psi}{lambda}, based on 1.2 fb{sup -1} of data collected with the D0 detector during 2002-2006. From 171 reconstructed {lambda}{sub b} decays, where the J/{psi} and {lambda} are identified via the decays J/{psi}{yields}{mu}{sup +}{mu}{sup -} and {lambda}{yields}p{pi}, we measured the {lambda}{sub b} lifetime to be {tau}({lambda}{sub b})=1.218{sub -0.115}{sup +0.130}(stat){+-}0.042(syst) ps. We also measured the B{sup 0} lifetime in the decay B{sup 0}{yields}J/{psi}({mu}{sup +}{mu}{sup -})K{sub S}{sup 0}({pi}{sup +}{pi}{sup -}) to be {tau}(B{sup 0})=1.501{sub -0.074}{sup +0.078}(stat){+-}0.050(syst) ps, yielding a lifetime ratio of {tau}({lambda}{sub b})/{tau}(B{sup 0})=0.811{sub -0.087}{sup +0.096}(stat){+-}0.034(syst = )

  20. Prediction of the Creep-Fatigue Lifetime of Alloy 617: An Application of Non-destructive Evaluation and Information Integration

    SciTech Connect (OSTI)

    Vivek Agarwal; Richard Wright; Timothy Roney

    2014-08-01

    A relatively simple method using the nominal constant average stress information and the creep rupture model is developed to predict the creep-fatigue lifetime of Alloy 617, in terms of time to rupture. The nominal constant average stress is computed using the stress relaxation curve. The predicted time to rupture can be converted to number of cycles to failure using the strain range, the strain rate during each cycle, and the hold time information. The predicted creep-fatigue lifetime is validated against the experimental measurements of the creep-fatigue lifetime collected using conventional laboratory creep-fatigue tests. High temperature creep-fatigue tests of Alloy 617 were conducted in air at 950°C with a tensile hold period of up to 1800s in a cycle at total strain ranges of 0.3% and 0.6%. It was observed that the proposed method is conservative in that the predicted lifetime is less than the experimentally determined values. The approach would be relevant to calculate the remaining useful life to a component like a steam generator that might fail by the creep-fatigue mechanism.

  1. Long lifetime, low intensity light source for use in nighttime viewing of equipment maps and other writings

    DOE Patents [OSTI]

    Frank, Alan M.; Edwards, William R.

    1983-01-01

    A long-lifetime light source with sufficiently low intensity to be used for reading a map or other writing at nighttime, while not obscuring the user's normal night vision. This light source includes a diode electrically connected in series with a small power source and a lens properly positioned to focus at least a portion of the light produced by the diode.

  2. Final Report on Work Performed Under Agreement

    SciTech Connect (OSTI)

    2012-04-15

    patent-pending low-e technology, EnerLogic® window film has the best insulating performance of any film product available. The insulating power of EnerLogic® window film gives single-pane windows the annual insulating performance of double-pane windows - and gives double-pane windows the annual insulating performance of triple-pane windows.

  3. Evaluation of the {sup 4}I{sub 11/2} terminal level lifetime for several neodymium-doped laser crystals and glasses

    SciTech Connect (OSTI)

    Bibeau, C.

    1995-04-25

    All models of lasing action require knowledge of the physical parameters involved, of which many can be measured or estimated. The value of the terminal level lifetime is an important parameter in modeling many high power laser systems since the terminal level lifetime can have a substantial impact on the extraction efficiency of the system. However, the values of the terminal level lifetimes for a number of important laser materials such as ND:YAG and ND:YLF are not well known. The terminal level lifetime, a measure of the time it takes for the population to drain out of the terminal (lower) lasing level, has values that can range from picoseconds to microseconds depending on the host medium, thus making it difficult to construct one definitive experiment for all materials. Until recently, many of the direct measurements of the terminal level lifetime employed complex energy extraction or gain recovery methods coupled with a numerical model which often resulted in large uncertainties in the measured lifetimes. In this report we demonstrate a novel and more accurate approach which employs a pump-probe technique to measure the terminal level lifetime of 16 neodymium-doped materials. An alternative yet indirect method, which is based on the ``Energy Gap Law,`` is to measure the nonradiative lifetime of another transition which has the same energy gap as the transition of the terminal level lifetime. Employing this simpler approach, we measured the lifetime for 30 neodymium-doped materials. We show for the first time a direct comparison between the two methods and determine that the indirect method can be used to infer the terminal level lifetime within a factor of two for most neodymium-doped glasses and crystals.

  4. Lifetime measurements of 17C excited states and three-body and continuum effects

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Smalley, D.; Iwasaki, H.; Navratil, P.; Roth, R.; Langhammer, J.; Bader, V. M.; Bazin, D.; Barryman, J. S.; Campbell, C. M.; Dohet-Eraly, J.; et al

    2015-12-18

    We studied transition rates for the lowest 1/2+ and 5/2+ excited states of 17C through lifetime measurements with the GRETINA array using the recoil-distance method. The present measurements provide a model-independent determination of transition strengths giving the values of B(M1;1/2+ → 3/2+g.s.) = 1.04+0.03–0.12 × 10–2μ2N and B(M1;5/2+ → 3/2+g.s.) = 7.12+1.27–0.96 × 10–2μ2N. The quenched M1 transition strength for the 1/2+ → 3/2+g.s. transition, with respect to the 5/2+ → 3/2+g.s. transition, has been confirmed with greater precision. Furthermore, the current data are compared to importance-truncated no-core shell model calculations addressing effects due to continuum and three-body forces.

  5. The lifetime of carbon capture and storage as a climate-change mitigation technology

    SciTech Connect (OSTI)

    Juanes, Ruben

    2013-12-30

    In carbon capture and storage (CCS), CO2 is captured at power plants and then injected underground into reservoirs like deep saline aquifers for long-term storage. While CCS may be critical for the continued use of fossil fuels in a carbon-constrained world, the deployment of CCS has been hindered by uncertainty in geologic storage capacities and sustainable injection rates, which has contributed to the absence of concerted government policy. Here, we clarify the potential of CCS to mitigate emissions in the United States by developing a storage-capacity supply curve that, unlike current large-scale capacity estimates, is derived from the fluid mechanics of CO2 injection and trapping and incorporates injection-rate constraints. We show that storage supply is a dynamic quantity that grows with the duration of CCS, and we interpret the lifetime of CCS as the time for which the storage supply curve exceeds the storage demand curve from CO2 production. We show that in the United States, if CO2 production from power generation continues to rise at recent rates, then CCS can store enough CO2 to stabilize emissions at current levels for at least 100 years. This result suggests that the large-scale implementation of CCS is a geologically viable climate-change mitigation option in the United States over the next century.

  6. Comparison of Minority Carrier Lifetime Measurements in Superstrate and Substrate CdTe PV Devices: Preprint

    SciTech Connect (OSTI)

    Gessert, T. A.; Dhere, R. G.; Duenow, J. N.; Kuciauskas, D.; Kanevce, A.; Bergeson, J. D.

    2011-07-01

    We discuss typical and alternative procedures to analyze time-resolved photoluminescence (TRPL) measurements of minority carrier lifetime (MCL) with the hope of enhancing our understanding of how this technique may be used to better analyze CdTe photovoltaic (PV) device functionality. Historically, TRPL measurements of the fast recombination rate (t1) have provided insightful correlation with broad device functionality. However, we have more recently found that t1 does not correlate as well with smaller changes in device performance, nor does it correlate well with performance differences observed between superstrate and substrate CdTe PV devices. This study presents TRPL data for both superstrate and substrate CdTe devices where both t1 and the slower TRPL decay (t2) are analyzed. The study shows that changes in performance expected from small changes in device processing may correlate better with t2. Numerical modeling further suggests that, for devices that are expected to have similar drift field in the depletion region, effects of changes in bulk MCL and interface recombination should be more pronounced in t2. Although this technique may provide future guidance to improving CdS/CdTe device performance, it is often difficult to extract statistically precise values for t2, and therefore t2 data may demonstrate significant scatter when correlated with performance parameters.

  7. Radio frequency coupling apparatus and method for measuring minority carrier lifetimes in semiconductor materials

    DOE Patents [OSTI]

    Johnston, Steven W.; Ahrenkiel, Richard K.

    2002-01-01

    An apparatus for measuring the minority carrier lifetime of a semiconductor sample using radio-frequency coupling. The measuring apparatus includes an antenna that is positioned a coupling distance from a semiconductor sample which is exposed to light pulses from a laser during sampling operations. A signal generator is included to generate high frequency, such as 900 MHz or higher, sinusoidal waveform signals that are split into a reference signal and a sample signal. The sample signal is transmitted into a sample branch circuit where it passes through a tuning capacitor and a coaxial cable prior to reaching the antenna. The antenna is radio-frequency coupled with the adjacent sample and transmits the sample signal, or electromagnetic radiation corresponding to the sample signal, to the sample and receives reflected power or a sample-coupled-photoconductivity signal back. To lower impedance and speed system response, the impedance is controlled by limiting impedance in the coaxial cable and the antenna reactance. In one embodiment, the antenna is a waveguide/aperture hybrid antenna having a central transmission line and an adjacent ground flange. The sample-coupled-photoconductivity signal is then transmitted to a mixer which also receives the reference signal. To enhance the sensitivity of the measuring apparatus, the mixer is operated to phase match the reference signal and the sample-coupled-photoconductivity signal.

  8. Long lifetime, low intensity light source for use in nighttime viewing of equipment maps and other writings

    DOE Patents [OSTI]

    Frank, A.M.; Edwards, W.R.

    1983-10-11

    A long-lifetime light source with sufficiently low intensity to be used for reading a map or other writing at nighttime, while not obscuring the user's normal night vision is disclosed. This light source includes a diode electrically connected in series with a small power source and a lens properly positioned to focus at least a portion of the light produced by the diode. 1 fig.

  9. Long lifetime, low intensity light source for use in nighttime viewing of equipment maps and other writings

    DOE Patents [OSTI]

    Frank, A.M.; Edwards, W.R.

    1982-03-23

    A long-lifetime light source is discussed with sufficiently low intensity to be used for reading a map or other writing at nightime, while not obscuring the user's normal night vision. This light source includes a diode electrically connected in series with a small power source and a lens properly positioned to focus at least a portion of the light produced by the diode.

  10. Highly resistive annealed low-temperature-grown InGaAs with sub-500 fs carrier lifetimes

    SciTech Connect (OSTI)

    Baker, C.; Gregory, I.S.; Tribe, W.R.; Bradley, I.V.; Evans, M.J.; Linfield, E.H.; Missous, M.

    2004-11-22

    We have optimized low-temperature-grown In{sub 0.3}Ga{sub 0.7}As for use in ultrafast photoconductive devices. Using low temperature ex situ annealing techniques, we have produced a photoconductive material that is highly resistive ({approx}10{sup 4} {omega} cm), has sub-500 fs carrier trapping lifetimes, and is matched to 1.06 {mu}m laser excitation.

  11. EqualWrites: Reducing Intra-set Write Variations for Enhancing Lifetime of Non-volatile Caches

    SciTech Connect (OSTI)

    Mittal, Sparsh; Vetter, Jeffrey S.

    2015-01-29

    Driven by the trends of increasing core-count and bandwidth-wall problem, the size of last level caches (LLCs) has greatly increased and hence, the researchers have explored non-volatile memories (NVMs) which provide high density and consume low-leakage power. Since NVMs have low write-endurance and the existing cache management policies are write variation-unaware, effective wear-leveling techniques are required for achieving reasonable cache lifetimes using NVMs. We present EqualWrites, a technique for mitigating intra-set write variation. In this paper, our technique works by recording the number of writes on a block and changing the cache-block location of a hot data-item to redirect the future writes to a cold block to achieve wear-leveling. Simulation experiments have been performed using an x86-64 simulator and benchmarks from SPEC06 and HPC (high-performance computing) field. The results show that for single, dual and quad-core system configurations, EqualWrites improves cache lifetime by 6.31X, 8.74X and 10.54X, respectively. In addition, its implementation overhead is very small and it provides larger improvement in lifetime than three other intra-set wear-leveling techniques and a cache replacement policy.

  12. Probing electronic lifetimes and phonon anharmonicities in high-quality chemical vapor deposited graphene by magneto-Raman spectroscopy

    SciTech Connect (OSTI)

    Neumann, Christoph Stampfer, Christoph; Halpaap, Donatus; Banszerus, Luca; Schmitz, Michael; Beschoten, Bernd; Reichardt, Sven; Watanabe, Kenji; Taniguchi, Takashi

    2015-12-07

    We present a magneto-Raman study on high-quality single-layer graphene grown by chemical vapor deposition (CVD) that is fully encapsulated in hexagonal boron nitride by a dry transfer technique. By analyzing the Raman D, G, and 2D peaks, we find that the structural quality of the samples is comparable with state-of-the-art exfoliated graphene flakes. From B-field dependent Raman measurements, we extract the broadening and associated lifetime of the G peak due to anharmonic effects. Furthermore, we determine the decay width and lifetime of Landau level (LL) transitions from magneto-phonon resonances as a function of laser power. At low laser power, we find a minimal decay width of 140 cm{sup −1} highlighting the high electronic quality of the CVD-grown graphene. At higher laser power, we observe an increase of the LL decay width leading to a saturation, with the corresponding lifetime saturating at a minimal value of 18 fs.

  13. Cryogenic Lifetime Studies of 130 nm and 65 nm CMOS Technologies for High-Energy Physics Experiments

    SciTech Connect (OSTI)

    Hoff, James R.; Deptuch, G. W.; Wu, Guoying; Gui, Ping

    2015-03-09

    The Long Baseline Neutrino Facility intends to use unprecedented volumes of liquid argon to fill a time projection chamber in an underground facility. Research is under way to place the electronics inside the cryostat. For reasons of efficiency and economics, the lifetimes of these circuits must be well in excess of 20 years. The principle mechanism for lifetime degradation of MOSFET devices and circuits operating at cryogenic temperatures is hot carrier degradation. Choosing a process technology that is, as much as possible, immune to such degradation and developing design techniques to avoid exposure to such damage are the goals. This, then, requires careful investigation and a basic understanding of the mechanisms that underlie hot carrier degradation and the secondary effects they cause in circuits. In this work, commercially available 130 nm and 65 nm nMOS transistors operating at cryogenic temperatures are investigated. Our results show that both technologies achieve the lifetimes required by the experiment. Minimal design changes are necessary in the case of the 130 nm process and no changes whatsoever are necessary for the 65 nm process.

  14. Evidence for the role of hydrogen in the stabilization of minority carrier lifetime in boron-doped Czochralski silicon

    SciTech Connect (OSTI)

    Nampalli, N. Hallam, B.; Chan, C.; Abbott, M.; Wenham, S.

    2015-04-27

    This study demonstrates that the presence of a hydrogen source during fast-firing is critical to the regeneration of B-O defects and that is it not a pure thermally based mechanism or due to plasma exposure. Boron-doped p-type wafers were fired with and without hydrogen-rich silicon nitride (SiN{sub x}:H) films present during the fast-firing process. After an initial light-induced degradation step, only wafers fired with the SiN{sub x}:H films present were found to undergo permanent and complete recovery of lifetime during subsequent illuminated annealing. In comparison, wafers fired bare, i.e., without SiN{sub x}:H films present during firing, were found to demonstrate no permanent recovery in lifetime. Further, prior exposure to hydrogen-rich plasma processing was found to have no impact on permanent lifetime recovery in bare-fired wafers. This lends weight to a hydrogen-based model for B-O defect passivation and casts doubt on the role of non-hydrogen species in the permanent passivation of B-O defects in commercial-grade p-type Czochralski silicon wafers.

  15. Charge and fluence lifetime measurements of a dc high voltage GaAs photogun at high average current

    SciTech Connect (OSTI)

    J. Grames, R. Suleiman, P.A. Adderley, J. Clark, J. Hansknecht, D. Machie, M. Poelker, M.L. Stutzman

    2011-04-01

    GaAs-based dc high voltage photoguns used at accelerators with extensive user programs must exhibit long photocathode operating lifetime. Achieving this goal represents a significant challenge for proposed high average current facilities that must operate at tens of milliamperes or more. This paper describes techniques to maintain good vacuum while delivering beam, and techniques that minimize the ill effects of ion bombardment, the dominant mechanism that reduces photocathode yield of a GaAs-based dc high voltage photogun. Experimental results presented here demonstrate enhanced lifetime at high beam currents by: (a) operating with the drive laser beam positioned away from the electrostatic center of the photocathode, (b) limiting the photocathode active area to eliminate photoemission from regions of the photocathode that do not support efficient beam delivery, (c) using a large drive laser beam to distribute ion damage over a larger area, and (d) by applying a relatively low bias voltage to the anode to repel ions created within the downstream beam line. A combination of these techniques provided the best total charge extracted lifetimes in excess of 1000 C at dc beam currents up to 9.5 mA, using green light illumination of bulk GaAs inside a 100 kV photogun.

  16. EqualWrites: Reducing Intra-set Write Variations for Enhancing Lifetime of Non-volatile Caches

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mittal, Sparsh; Vetter, Jeffrey S.

    2015-01-29

    Driven by the trends of increasing core-count and bandwidth-wall problem, the size of last level caches (LLCs) has greatly increased and hence, the researchers have explored non-volatile memories (NVMs) which provide high density and consume low-leakage power. Since NVMs have low write-endurance and the existing cache management policies are write variation-unaware, effective wear-leveling techniques are required for achieving reasonable cache lifetimes using NVMs. We present EqualWrites, a technique for mitigating intra-set write variation. In this paper, our technique works by recording the number of writes on a block and changing the cache-block location of a hot data-item to redirect themore » future writes to a cold block to achieve wear-leveling. Simulation experiments have been performed using an x86-64 simulator and benchmarks from SPEC06 and HPC (high-performance computing) field. The results show that for single, dual and quad-core system configurations, EqualWrites improves cache lifetime by 6.31X, 8.74X and 10.54X, respectively. In addition, its implementation overhead is very small and it provides larger improvement in lifetime than three other intra-set wear-leveling techniques and a cache replacement policy.« less

  17. Tips: Your Home's Energy Use | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    to you-for example, increased comfort from installing double-paned, efficient windows? ... How much time do you have for maintenance and repairs? A thermal image-taken by a ...

  18. Sales Tax Incentives for Energy-Efficient Manufactured Homes...

    Broader source: Energy.gov (indexed) [DOE]

    storm or double-pane glass windows, insulated or storm doors; and a minimum thermal resistance (R) rating of the insulation of R-11 for walls, R-19 for floors and R-30 for...

  19. Quantum efficiency temporal response and lifetime of a GaAs cathode in SRF electron gun

    SciTech Connect (OSTI)

    Wang, E.; Ben-Zvi, I.; Kewisch, J.; Burrill, A.; Rao, T.; Wu, Q.; Holmes, D.

    2010-05-23

    RF electron guns with a strained super lattice GaAs cathode can generate polarized electron beam of higher brightness and lower emittance than do DC guns, due to their higher field gradient at the cathode's surface. In a normal conducting RF gun, the extremely high vaccum required by these cathodes can not be met. We report on an experiment with a superconducting SRF gun, which can maintain a vacuum of nearly 10-12 torr because of cryo-pumping at the temperature of 4.2K. With conventional activation, we obtained a QE of 3% at 532 nm, with lifetime of nearly 3 days in the preparation chamber. We plan to use this cathode in a 1.3 GHz 1/2 cell SRF gun to study its performance. In addition, we studied the multipacting at the location of cathode. A new model based on the Forkker-Planck equation which can estimate the bunch length of the electron beam is discussed in this paper. Future particle accelerators such as eRHIC and ILC require high brightness, high current polarized electrons Recently, using a superlattice crystal, the maximum polarization of 95% was reached. Activation with Cs,O lowers the electron affinity and makes it energetically possible for all the electrons excited in to the conduction band and reach the surface to escape into the vacuum. Presently the polarized electron sources are based on DC gun, such as that at the CEBAF at Jlab. In these devices, the life time of the cathode is extended due to the reduced back bombardment in their UHV conditions. However, the low accelerating gradient of the DC guns lead to poor longitudinal emittance. The higher accelerating gradient of the RF gun generates low emittance beams. Superconducting RF guns combine the excellent vacuum conditions of the DC guns with the higher accelerating gradients of the RF guns and provide potentially a long lived cathode with very low transverse and longitudinal emittance. In our work at BNL, we successfully activated the GaAs. The quantum efficient is 3% at 532 nm and is expected

  20. Spontaneous Fission Modes and Lifetimes of Superheavy Elements in the Nuclear Density Functional Theory

    SciTech Connect (OSTI)

    Staszczak, A,

    2013-01-01

    Background: The reactions with the neutron-rich 48Ca beam and actinide targets resulted in the detection of new superheavy (SH) nuclides with Z=104 118. The unambiguous identification of the new isotopes, however, still poses a problem because their -decay chains terminate by spontaneous fission (SF) before reaching the known region of the nuclear chart. The understanding of the competition between -decay and SF channels in SH nuclei is, therefore, of crucial importance for our ability to map the SH region and to assess its extent.

    Purpose: We perform self-consistent calculations of the competing decay modes of even-even SH isotopes with 108 Z 126 and 148 N 188.

    Methods: We use the state-of-the-art computational framework based on self-consistent symmetry-unrestricted nuclear density functional theory capable of describing the competition between nuclear attraction and electrostatic repulsion. We apply the SkM* Skyrme energy density functional. The collective mass tensor of the fissioning superfluid nucleus is computed by means of the cranking approximation to the adiabatic time-dependent Hartree-Fock-Bogoliubov (HFB) approach. This paper constitutes a systematic self-consistent study of spontaneous fission in the SH region, carried out at a full HFB level, that simultaneously takes into account both triaxiality and reflection asymmetry.

    Results: Breaking axial symmetry and parity turns out to be crucial for a realistic estimate of collective action; it results in lowering SF lifetimes by more than 7 orders of magnitude in some cases. We predict two competing SF modes: reflection symmetric modes and reflection asymmetric modes.

    Conclusions: The shortest-lived SH isotopes decay by SF; they are expected to lie in a narrow corridor formed by 280Hs, 284Fl, and 118284Uuo that separates the regions of SH nuclei synthesized in cold-fusion and hot-fusion reactions. The region of long-lived SH nuclei is expected to be centered on 294Ds with a total half-life of

  1. Effect of charge trapping on effective carrier lifetime in compound semiconductors: High resistivity CdZnTe

    SciTech Connect (OSTI)

    Kamieniecki, Emil

    2014-11-21

    The dominant problem limiting the energy resolution of compound semiconductor based radiation detectors is the trapping of charge carriers. The charge trapping affects energy resolution through the carrier lifetime more than through the mobility. Conventionally, the effective carrier lifetime is determined using a 2-step process based on measurement of the mobility-lifetime product (μτ) and determining drift mobility using time-of-flight measurements. This approach requires fabrication of contacts on the sample. A new RF-based pulse rise-time method, which replaces this 2-step process with a single non-contact direct measurement, is discussed. The application of the RF method is illustrated with high-resistivity detector-grade CdZnTe crystals. The carrier lifetime in the measured CdZnTe, depending on the quality of the crystals, was between about 5 μs and 8 μs. These values are in good agreement with the results obtained using conventional 2-step approach. While the effective carrier lifetime determined from the initial portion of the photoresponse transient combines both recombination and trapping in a manner similar to the conventional 2-step approach, both the conventional and the non-contact RF methods offer only indirect evaluation of the effect of charge trapping in the semiconductors used in radiation detectors. Since degradation of detector resolution is associated not with trapping but essentially with detrapping of carriers, and, in particular, detrapping of holes in n-type semiconductors, it is concluded that evaluation of recombination and detrapping during photoresponse decay is better suited for evaluation of compound semiconductors used in radiation detectors. Furthermore, based on previously reported data, it is concluded that photoresponse decay in high resistivity CdZnTe at room temperature is dominated by detrapping of carriers from the states associated with one type of point defect and by recombination of carriers at one type of

  2. Measurement of the ?b? lifetime in the exclusive decay ?b??J/??? in pp? collisions at ?s=1.96 TeV

    SciTech Connect (OSTI)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Aoki, M.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besanon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bose, T.; Brandt, A.; Brandt, O.; Brock, R.; Brooijmans, G.; Bross, A.; Brown, D.; Brown, J.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Prez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Chevalier-Thry, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Croc, A.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Dliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duggan, D.; Duperrin, A.; Dutt, S.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Facini, G.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garcia-Bellido, A.; Garca-Gonzlez, J. A.; Garca-Guerra, G. A.; Gavrilov, V.; Gay, P.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grnendahl, S.; Grnewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haas, A.; Hagopian, S.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hohlfeld, M.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffr, M.; Jayasinghe, A.; Jesik, R.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kaadze, K.; Kajfasz, E.; Karmanov, D.; Kasper, P. A.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lellouch, J.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaa-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martnez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Naimuddin, M.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nunnemann, T.; Obrant, G.; Orduna, J.; Osman, N.; Osta, J.; Padilla, M.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Ptroff, P.; Pleier, M.-A.; Podesta-Lerma, P. L. M.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Rangel, M. S.; Ranjan, K.; Ratoff, P. N.; Razumov, I.; Renkel, P.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Salcido, P.; Snchez-Hernndez, A.; Sanders, M. P.; Sanghi, B.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schlobohm, S.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Shivpuri, R. K.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Smith, K. J.; Snow, G. R.; Snow, J.; Snyder, S.; Sldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Stutte, L.; Suter, L.; Svoisky, P.; Takahashi, M.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tschann-Grimm, K.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.

    2012-06-07

    We measure the ??b lifetime in the fully reconstructed decay ??b?J/??? using 10.4 fb? of pp? collisions collected with the D0 detector at ?s=1.96 TeV. The lifetime of the topologically similar decay channel B??J/?K?S is also measured. We obtain ?(??b)=1.3030.075(stat)0.035(syst) ps and ?(B?)=1.5080.025(stat)0.043(syst) ps. Using these measurements, we determine the lifetime ratio of ?(??b)/?(B?)=0.8640.052(stat)0.033(syst).

  3. 2016-2020 Strategic Human Capital Plan

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    the Chief Human Capital Officer 2016-2020 Strategic Human Capital Plan Cover Photo Description Beyond Double-Pane Windows While the invention of double-pane windows dates back to 1935, a true turning point in the technology came in the 1980s with a collaboration between the Department of Energy, private industry, and Lawrence Berkeley National Lab. Initial research and development by Berkeley Lab and a start-up company, Suntek Research Associates (now called Southwall Technologies), led to the

  4. The core mass growth and stellar lifetime of thermally pulsing asymptotic giant branch stars

    SciTech Connect (OSTI)

    Kalirai, Jason S.; Tremblay, Pier-Emmanuel; Marigo, Paola E-mail: paola.marigo@unipd.it

    2014-02-10

    We establish new constraints on the intermediate-mass range of the initial-final mass relation, and apply the results to study the evolution of stars on the thermally pulsing asymptotic giant branch (TP-AGB). These constraints derive from newly discovered (bright) white dwarfs in the nearby Hyades and Praesepe star clusters, including a total of 18 high signal-to-noise ratio measurements with progenitor masses of M {sub initial} = 2.8-3.8 M {sub ?}. We also include a new analysis of existing white dwarfs in the older NGC 6819 and NGC 7789 star clusters, M {sub initial} = 1.6 and 2.0 M {sub ?}. Over this range of initial masses, stellar evolutionary models for metallicity Z {sub initial} = 0.02 predict the maximum growth of the core of TP-AGB stars. By comparing the newly measured remnant masses to the robust prediction of the core mass at the first thermal pulse on the AGB (i.e., from stellar interior models), we establish several findings. First, we show that the stellar core mass on the AGB grows rapidly from 10% to 30% for stars with M {sub initial} = 1.6 to 2.0 M {sub ?}. At larger masses, the core-mass growth decreases steadily to ?10% at M {sub initial} = 3.4 M {sub ?}, after which there is a small hint of a upturn out to M {sub initial} = 3.8 M {sub ?}. These observations are in excellent agreement with predictions from the latest TP-AGB evolutionary models in Marigo et al. We also compare to models with varying efficiencies of the third dredge-up and mass loss, and demonstrate that the process governing the growth of the core is largely the stellar wind, while the third dredge-up plays a secondary, but non-negligible role. Based on the new white dwarf measurements, we perform an exploratory calibration of the most popular mass-loss prescriptions in the literature, as well as of the third dredge-up efficiency as a function of the stellar mass. Finally, we estimate the lifetime and the integrated luminosity of stars on the TP-AGB to peak at t ? 3 Myr and E

  5. Bias current dependence of the spin lifetime in insulating Al{sub 0.3}Ga{sub 0.7}As

    SciTech Connect (OSTI)

    Misuraca, Jennifer Kim, Joon-Il; Xiong, Peng; Molnár, Stephan von; Lu, Jun; Meng, Kangkang; Chen, Lin; Yu, Xuezhe; Zhao, Jianhua

    2014-02-24

    The spin lifetime and Hanle signal amplitude dependence on bias current has been investigated in insulating Al{sub 0.3}Ga{sub 0.7}As:Si using a three-terminal Hanle effect geometry. The amplitudes of the Hanle signals are much larger for forward bias than for reverse bias, although the spin lifetimes found are statistically equivalent. The spin resistance-area product shows a strong increase with bias current for reverse bias and small forward bias until 150 μA, beyond which a weak dependence is observed. The spin lifetimes diminish substantially with increasing bias current. The dependence of the spin accumulation and lifetime diminish only moderately with temperature from 5 K to 30 K.

  6. Minority carrier lifetime and dark current measurements in mid-wavelength infrared InAs0.91Sb0.09 alloy nBn photodetectors

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Olson, B. V.; Kim, J. K.; Kadlec, E. A.; Klem, J. F.; Hawkins, S. D.; Leonhardt, D.; Coon, W. T.; Fortune, T. R.; Cavaliere, M. A.; Tauke-Pedretti, A.; et al

    2015-11-03

    Carrier lifetime and dark current measurements are reported for a mid-wavelength infrared InAs 0.91Sb0.09 alloy nBn photodetector. Minority carrier lifetimes are measured using a non-contact time-resolved microwave technique on unprocessed portions of the nBn wafer and the Auger recombination Bloch function parameter is determined to be |F1F2|=0.292. Moreover, the measured lifetimes are also used to calculate the expected diffusion dark current of the nBn devices and are compared with the experimental dark current measured in processed photodetector pixels from the same wafer. As a result, excellent agreement is found between the two, highlighting the important relationship between lifetimes and diffusionmore » currents in nBn photodetectors.« less

  7. 3D-resolved determination of minority-carrier lifetime in planar silicon solar cells by photocurrent decay

    SciTech Connect (OSTI)

    Verhoef, L.A.; Stroom, J.C.; Bisschop, F.J.; Liefting, J.R.; Sinke, W.C. )

    1990-12-15

    In modern production schemes for Si solar cells, defect passivation and impurity gettering are often used to improve material quality and thereby cell efficiency. These processes generally alter the spatial uniformity of minority-carrier transport parameters over the wafer and may result in minority-carrier lifetime and diffusion length variations both lateral and in depth. In polycrystalline Si these spatial dependences are already present due to the nature of the material. We present an extension of the photocurrent decay method to determine the diffusion length in a three-dimensionally resolved fashion. From a single photocurrent decay curve the back-surface recombination velocity, the average minority-carrier diffusion length, and an asymmetry factor which qualitatively describes the depth dependence of the diffusion length are determined. This is done using the three observables: quantum efficiency, fundamental decay time, and intercept of the extrapolated decay curve with the time-zero axis. Lateral resolution is obtained by focusing the light beam to a small spot on the cell and measuring the current decay curve as a function of position on the cell. It is shown that light-pulse durations longer than the minority-carrier lifetime and wavelengths longer than 950 nm are required. These conditions are met by using modulated wavelength-tunable light from a Ti:sapphire laser. Measurements on monocrystalline cells show that the decay time is independent of wavelength and light-pulse duration, as predicted by theory. Furthermore, the intercept with the time-zero axis was shown to increase with increasing pulse duration and wavelength. Measurements on a set of polycrystalline Si cells were performed showing that gettering treatments during cell production result in depth-dependent lifetimes.

  8. US/UK second level panel discussions on the health and value of: Ageing and lifetime predictions (u)

    SciTech Connect (OSTI)

    Castro, Richard G

    2011-01-18

    Many healthy physics, engineering, and materials exchanges are being accomplished in ageing and lifetime prediction that directly supports US and UK Stockpile Management Programs. Lifetime assessment studies of silicon foams under compression - Joint AWE/LANLlLLNL study of compression set in stress cushions completed. Provides phenomenological prediction out to 50 years. Polymer volatile out-gassing studies - New exchange on the out-gassing of Ethylene Vinyl Acetate (EVA) using isotopic {sup 13}C labeling studies to interrogate mechanistic processes. Infra-red (IR) gas cell analytical capabilities developed by AWE will be used to monitor polymer out-gassing profiles. Pu Strength ageing Experiments and Constitutive Modeling - In recently compared modeling strategies for ageing effects on Pu yield strength at high strain rates, a US/UK consensus was reached on the general principle that the ageing effect is additive and not multiplicative. The fundamental mechanisms for age-strengthening in Pu remains unknown. Pu Surface and Interface Reactions - (1) US/UK secondment resulted in developing a metal-metal oxide model for radiation damaged studies consistent with a Modified Embedded Atom Method (MEAM) potential; and (2) Joint US/UK collaboration to study the role of impurities in hydride initiation. Detonator Ageing (wide range of activities) - (1) Long-term ageing study with field trials at Pantex incorporating materials from LANL, LLNL, SNL and AWE; (2) Characterization of PETN growth to detonation process; (3) Detonator performance modeling; and (4) Performance fault tree analysis. Benefits are a unified approach to lifetime prediction that Includes: materials characterization and the development of ageing models through improved understanding of the relationship between materials properties, ageing properties and detonator performance.

  9. A Measurement of the Lifetime of the Lambda_b Baryon with the CDF Detector at the Tevatron Run II

    SciTech Connect (OSTI)

    Unverhau, Tatjana Alberta Hanna; /Glasgow U.

    2004-12-01

    In March 2001 the Tevatron accelerator entered its Run II phase, providing colliding proton and anti-proton beams with an unprecedented center-of-mass energy of 1.96 TeV. The Tevatron is currently the only accelerator to produce {Lambda}{sub b} baryons, which provides a unique opportunity to measure the properties of these particles. This thesis presents a measurement of the mean lifetime of the {Lambda}{sub b} baryon in the semileptonic channel {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +} {mu}{sup -} {bar {nu}}{sub {mu}}. In total 186 pb{sup -1} of data were used for this analysis, collected with the CDF detector between February 2002 and September 2003. To select the long-lived events from b-decays, the secondary vertex trigger was utilized. This significant addition to the trigger for Run II allows, for the first time, the selection of events with tracks displaced from the primary interaction vertex at the second trigger level. After the application of selection cuts this trigger sample contains approximately 991 {Lambda}{sub b} candidates. To extract the mean lifetime of {Lambda}{sub b} baryons from this sample, they transverse decay length of the candidates is fitted with an unbinned maximum likelihood fit under the consideration of the missing neutrino momentum and the bias introduced by the secondary vertex trigger. The mean lifetime of the {Lambda}{sub b} is measured to be {tau} = 1.29 {+-} 0.11(stat.) {+-} 0.07(syst.) ps equivalent to a mean decay length of c{tau} = 387 {+-} 33(stat.) {+-} 21 (syst.) {micro}m.

  10. Neutron lifetimes behavior analysis considering the two-region kinetic model in the IPEN/MB-01 reactor

    SciTech Connect (OSTI)

    Gonnelli, Eduardo; Diniz, Ricardo

    2014-11-11

    This is a complementary work about the behavior analysis of the neutron lifetimes that was developed in the IPEN/MB-01 nuclear reactor facility. The macroscopic neutron noise technique was experimentally employed using pulse mode detectors for two stages of control rods insertion, where a total of twenty levels of subcriticality have been carried out. It was also considered that the neutron reflector density was treated as an additional group of delayed neutrons, being a sophisticated approach in the two-region kinetic theoretical model.

  11. Value Proposition for High Lifetime (p-type) and Thin Silicon Materials in Solar PV Applications: Preprint

    SciTech Connect (OSTI)

    Goodrich, A.; Woodhouse, M.; Hacke, P.

    2012-06-01

    Most silicon PV road maps forecast a continued reduction in wafer thickness, despite rapid declines in the primary incentive for doing so -- polysilicon feedstock price. Another common feature of most silicon-technology forecasts is the quest for ever-higher device performance at the lowest possible costs. The authors present data from device-performance and manufacturing- and system-installation cost models to quantitatively establish the incentives for manufacturers to pursue advanced (thin) wafer and (high efficiency) cell technologies, in an age of reduced feedstock prices. This analysis exhaustively considers the value proposition for high lifetime (p-type) silicon materials across the entire c-Si PV supply chain.

  12. Investigation of long lifetimes in Cu(In,Ga)Se{sub 2} by time-resolved photoluminescence

    SciTech Connect (OSTI)

    Maiberg, Matthias; Hölscher, Torsten; Zahedi-Azad, Setareh; Fränzel, Wolfgang; Scheer, Roland

    2015-09-21

    The main objective of time-resolved photoluminescence (TRPL) is to characterize minority carrier recombination in semiconductors. However, trap states in the band gap can lead to artificially long decay times thus distorting the measured minority carrier lifetime. In this work, we propose to measure TRPL under elevated temperature and excitation in order to reduce minority carrier trapping. Taking three Cu(In,Ga)Se{sub 2} layers as examples, we show that the decay time decreases with increasing temperature—in accordance with simulations. Under increasing excitation, the decay time can become smaller due to trap saturation but also can become larger due to asymmetric hole and electron lifetimes. By comparison of simulation and experiment, we can find the energy, the density, and the electron capture cross-section of the trap which in the present example of Cu(In,Ga)Se{sub 2} films gives values of ∼200 meV, ∼10{sup 15 }cm{sup −3}, and ∼10{sup −13} cm{sup 2}, respectively.

  13. Modelled Black Carbon Radiative Forcing and Atmospheric Lifetime in AeroCom Phase II Constrained by Aircraft Observations

    SciTech Connect (OSTI)

    Samset, B. H.; Myhre, G.; Herber, Andreas; Kondo, Yutaka; Li, Shao-Meng; Moteki, N.; Koike, Makoto; Oshima, N.; Schwarz, Joshua P.; Balkanski, Y.; Bauer, S.; Bellouin, N.; Berntsen, T.; Bian, Huisheng; Chin, M.; Diehl, Thomas; Easter, Richard C.; Ghan, Steven J.; Iversen, T.; Kirkevag, A.; Lamarque, Jean-Francois; Lin, Guang; Liu, Xiaohong; Penner, Joyce E.; Schulz, M.; Seland, O.; Skeie, R. B.; Stier, P.; Takemura, T.; Tsigaridis, Kostas; Zhang, Kai

    2014-11-27

    Black carbon (BC) aerosols absorb solar radiation, and are generally held to exacerbate global warming through exerting a positive radiative forcing1. However, the total contribution of BC to the ongoing changes in global climate is presently under debate2-8. Both anthropogenic BC emissions and the resulting spatial and temporal distribution of BC concentration are highly uncertain2,9. In particular, long range transport and processes affecting BC atmospheric lifetime are poorly understood, leading to large estimated uncertainty in BC concentration at high altitudes and far from emission sources10. These uncertainties limit our ability to quantify both the historical, present and future anthropogenic climate impact of BC. Here we compare vertical profiles of BC concentration from four recent aircraft measurement campaigns with 13 state of the art aerosol models, and show that recent assessments may have overestimated present day BC radiative forcing. Further, an atmospheric lifetime of BC of less than 5 days is shown to be essential for reproducing observations in transport dominated remote regions. Adjusting model results to measurements in remote regions, and at high altitudes, leads to a 25% reduction in the multi-model median direct BC forcing from fossil fuel and biofuel burning over the industrial era.

  14. Phase-resolved nanosecond spectrofluorometry: theory, instrumentation, and new applications of multicomponent analysis by subnanosecond fluorescence lifetimes

    SciTech Connect (OSTI)

    Mattheis, J.R.; Mitchell, G.W.; Spencer, R.D.

    1982-03-01

    We describe a new method, phase-resolved subnanosecond spectroscopy (PRS), for the spectral differentiation of fluorophores in a mixture. The technique required adding a phase-variable rectifying detector to the SLM 4800S phasespectrofluorometer. The theory of PRS is based on the sinusoidal fluorescence emission of a population of molecules in response to sinusodially modulated exicitation light. The total a-c fluorescence signal is passed through the phase-variable detector which nulls the emission signal of any component in quadrature with the reference angle. The emission characteristics of the remaining component, or components, are more readily and accurately revealed. We investigated the sensitivity and selectivity of PRS. The sensitivity of PRS was demonstrated by nulling the contribution of the Raman scatter band of a nanomolar solution of quinine bisulfate to the real-time emission spectrum resolved at 8-nm bandpass. We demonstrated the selectivity of PRS by resolving the emission spectrum of anthracene and perylene from a 1 : 1 mixture with a lifetime differential of only 600 ps. The emission spectra of 2.2-phenylene bis-(5-phenyloxazole) and dimethyl 2.2-phenylene bis-(5-phenyloxazole) were also resolved from a 1 : 1 mixture in ethanol. The lifetime differential here was only 200 ps.

  15. Measurement of the B0s lifetime in the flavor-specific decay channel B0s ? D-s?+?X

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazov, Victor Mukhamedovich

    2015-02-09

    We present an updated measurement of the B0s lifetime using the semileptonic decays B0s ? D-s?+?X, with Ds ? ? and ? ? K+K (and the charge conjugate process). This measurement uses the full Tevatron Run II sample of proton-antiproton collisions at ?s = 1.96 TeV, comprising an integrated luminosity of 10.4 fb1. We find a flavor-specific lifetime ?fs(B0s) = 1.479 0.010(stat) 0.021(syst) ps. This technique is also used to determine the B0 lifetime using the analogous B0 ? D?+?X decay with D ? ?? and ? ? K+K, yielding ?(B0) = 1.534 0.019(stat) 0.021(syst) ps.moreBoth measurements are consistent with the current world averages, and the B0s lifetime measurement is one of the most precise to date. As a result, taking advantage of the cancellation of systematic uncertainties, we determine the lifetime ratio ?fs(B0s)/?(B0) = 0.964 0.013(stat) 0.007(syst).less

  16. Couplings between hierarchical conformational dynamics from multi-time correlation functions and two-dimensional lifetime spectra: Application to adenylate kinase

    SciTech Connect (OSTI)

    Ono, Junichi; Takada, Shoji; Saito, Shinji

    2015-06-07

    An analytical method based on a three-time correlation function and the corresponding two-dimensional (2D) lifetime spectrum is developed to elucidate the time-dependent couplings between the multi-timescale (i.e., hierarchical) conformational dynamics in heterogeneous systems such as proteins. In analogy with 2D NMR, IR, electronic, and fluorescence spectroscopies, the waiting-time dependence of the off-diagonal peaks in the 2D lifetime spectra can provide a quantitative description of the dynamical correlations between the conformational motions with different lifetimes. The present method is applied to intrinsic conformational changes of substrate-free adenylate kinase (AKE) using long-time coarse-grained molecular dynamics simulations. It is found that the hierarchical conformational dynamics arise from the intra-domain structural transitions among conformational substates of AKE by analyzing the one-time correlation functions and one-dimensional lifetime spectra for the donor-acceptor distances corresponding to single-molecule Förster resonance energy transfer experiments with the use of the principal component analysis. In addition, the complicated waiting-time dependence of the off-diagonal peaks in the 2D lifetime spectra for the donor-acceptor distances is attributed to the fact that the time evolution of the couplings between the conformational dynamics depends upon both the spatial and temporal characters of the system. The present method is expected to shed light on the biological relationship among the structure, dynamics, and function.

  17. Measurement of the B?s lifetime in the flavor-specific decay channel B?s ? D?s ???X

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazov, V.? M.; Abbott, B.; Acharya, B.? S.; Adams, M.; Adams, T.; Agnew, J.? P.; Alexeev, G.? D.; Alkhazov, G.; Alton, A.; Askew, A.; et al

    2015-02-09

    We present an updated measurement of the B?s lifetime using the semileptonic decays B?s ? D?s ???X, with D?s ? ??? and ? ? K?K? (and the charge conjugate process). This measurement uses the full Tevatron Run II sample of proton-antiproton collisions at ?s = 1.96 TeV, comprising an integrated luminosity of 10.4 fb?1. We find a flavor-specifc lifetime Tfs(B?s) = 1.479 0.010 (stat) 0.021 (syst) ps. This technique is also used to determine the B? lifetime using the analogous B? ? D????X decay with D? ? ??? and ? ? K?K? , yielding T(B?) = 1.534 more0.019 (stat) 0.021 (syst) ps. Both measurements are consistent with the current world averages, and the B?s lifetime measurement is one of the most precise to date. Taking advantage of the cancellation of systematic uncertainties, we determine the lifetime ratio Tfs(B?s)/T(B?) = 0.964 0.013 (stat) 0.007 (syst).less

  18. Measurement of the B0s lifetime in the flavor-specific decay channel B0s → D-sμ+νX

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazov, Victor Mukhamedovich

    2015-02-09

    We present an updated measurement of the B0s lifetime using the semileptonic decays B0s → D-sμ+νX, with D–s → π– and Φ → K+K– (and the charge conjugate process). This measurement uses the full Tevatron Run II sample of proton-antiproton collisions at √s = 1.96 TeV, comprising an integrated luminosity of 10.4 fb–1. We find a flavor-specific lifetime τfs(B0s) = 1.479 ± 0.010(stat) ± 0.021(syst) ps. This technique is also used to determine the B0 lifetime using the analogous B0 → D–μ+νX decay with D– → Φπ– and Φ → K+K–, yielding τ(B0) = 1.534 ± 0.019(stat) ± 0.021(syst) ps.more » Both measurements are consistent with the current world averages, and the B0s lifetime measurement is one of the most precise to date. As a result, taking advantage of the cancellation of systematic uncertainties, we determine the lifetime ratio τfs(B0s)/τ(B0) = 0.964 ± 0.013(stat) ± 0.007(syst).« less

  19. Ab initio energies and tunneling lifetimes of the doubly charged AH{sup 2+} (A = Mg-Ar) diatomics

    SciTech Connect (OSTI)

    Nefedova, V.V.; Boldyrev, A.I.; Simons, J.

    1995-09-15

    Potential energy curves for the ground and low-lying excited states of the AH{sup 2+} (A = Mg-Ar) dications have been calculated using high-level ab initio methods with large atomic orbital basis sets. Quasi-bound potential energy curves with local minima and deprotonation barriers have been found for most of the dications studied. The energies, tunneling lifetimes, and widths of the quasi-bound states have been calculated by numerical solution of the radial Schroedinger equation using the Numeov method. All these dications except ArH{sup 2+} have low-lying states which support quasi-bound vibrational states. The ArH{sup 2+} dication has a {sup 2}{Pi}{sub i} potential energy curve with a minimum so shallow that it does not support any quasi-bound vibrational states. Results of our calculations are compared with previous ab initio calculations and available experimental data. 24 refs., 8 figs., 12 tabs.

  20. Determination of CdTe bulk carrier lifetime and interface recombination velocity of CdTe/MgCdTe double heterostructures grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Zhao, Xin-Hao; Campbell, Calli M.; DiNezza, Michael J.; Liu, Shi; Zhao, Yuan; Zhang, Yong-Hang

    2014-12-22

    The bulk Shockley-Read-Hall carrier lifetime of CdTe and interface recombination velocity at the CdTe/Mg{sub 0.24}Cd{sub 0.76}Te heterointerface are estimated to be around 0.5??s and (4.7??0.4)??10{sup 2?}cm/s, respectively, using time-resolved photoluminescence (PL) measurements. Four CdTe/MgCdTe double heterostructures (DHs) with varying CdTe layer thicknesses were grown on nearly lattice-matched InSb (001) substrates using molecular beam epitaxy. The longest lifetime of 179?ns is observed in the DH with a 2??m thick CdTe layer. It is also shown that the photon recycling effect has a strong influence on the bulk radiative lifetime, and the reabsorption process affects the measured PL spectrum shape and intensity.

  1. MiniBooNE LowE Data Release

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Unexplained Excess of Electron-Like Events From a 1 GeV Neutrino Beam", arXiv:0812.2243 [hep-ex], Phys. Rev. Lett. 102, 101802 (2009) The following MiniBooNE information from the 2009 updated nue oscillation paper is made available to the public: Energy Range for Default Oscillation Fit (475 MeV - 3000 MeV reconstructed neutrino energy) 1D array of bin boundaries in electron neutrino reconstructed neutrino energy 1D array of observed electron neutrino candidate events per reconstructed

  2. Low E Brings High Savings in Newark, Delaware

    Broader source: Energy.gov [DOE]

    Newark, Delaware used an Energy Efficiency and Conservation Block Grant to install energy efficient windows and lights.

  3. MiniBooNE LowE Data Release

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Excess of Electron-Like Events From a 1 GeV Neutrino Beam", arXiv:0812.2243 hep-ex, Phys. Rev. Lett. 102, 101802 (2009) The following MiniBooNE information from the 2009...

  4. PowerSlicing to determine fluorescence lifetimes of water-soluble organic matter derived from soils, plant biomass, and animal manures

    SciTech Connect (OSTI)

    Ohno, Tsutomu; Wang, Zheming; Bro, Rasmus

    2008-04-01

    Time-resolved fluorescence spectroscopy was used to characterize water-soluble organic matter (WSOM) which plays an important role in soil ecosystem processes. WSOM was extracted from plant biomass, animal manures, and soils from controlled cropping systems studies with known histories of organic amendments. Lifetime constants were derived using the multi-way PowerSlicing method which provides a non-iterative, multi-exponential fitting of decay profiles. The lifetimes obtained by PowerSlicing were not significantly different from those obtained using the traditional discrete components analysis. The three components attributed to WSOM had lifetimes of 0.38 0.14, 2.110.72, and 7.081.18 ns which are in agreement with previous lifetimes reported for humic substances. This study provides further support for the new paradigm for the structure of soil organic matter where the organic matter is composed of low-molecular-weight components held together by hydrogen bonding and hydrophobic interactions.

  5. Effects of Cu Diffusion from ZnTe:Cu/Ti Contacts on Carrier Lifetime of CdS/CdTe Thin Film Solar Cells: Preprint

    SciTech Connect (OSTI)

    Gessert, T. A.; Metzger, W. K.; Asher, S. E.; Young, M. R.; Johnston, S.; Dhere, R. G.; Duda, A.

    2008-05-01

    We study the performance of CdS/CdTe thin film PV devices processed with a ZnTe:Cu/Ti contact to investigate how carrier lifetime in the CdTe layer is affected by Cu diffusion from the contact.

  6. Measurement of the B+-_c Meson Lifetime Using B+-_c -> J/psi + l+- + X Decays

    SciTech Connect (OSTI)

    Hartz, Mark Patrick; /Pittsburgh U.

    2008-11-01

    This thesis describes a measurement of the average proper decay time of the B{sub c}{sup {+-}} mesons, the ground state of bottom and charm quark bound states. The lifetime measurement is carried out in the decay modes B{sub c}{sup {+-}} {yields} J/{psi} + e{sup {+-}} + X and B{sub c}{sup {+-}} {yields} J/{psi} + {mu}{sup {+-}} + X, where the J/{psi} decays as J/{psi} {yields} {mu}{sup +}{mu}{sup -} and the X are unmeasured particles such as {nu}{sub e} or {nu}{sub {mu}}. The data are collect by the CDF II detector which measures the properties of particles created in {radical}s = 1.96 TeV p{bar p} collisions delivered by the Fermilab Tevatron. This measurement uses {approx} 1 fb{sup -1} of integrated luminosity. The measured average proper decay time of B{sub c}{sup {+-}} mesons, {tau} = 0.475{sub -0.049}{sup +0.053}(stat.) {+-} 0.018(syst.) ps, is competitive with the most precise measurements in the world and confirms previous measurements and theoretical predictions.

  7. Testing and Analysis for Lifetime Prediction of Crystalline Silicon PV Modules Undergoing Degradation by System Voltage Stress: Preprint

    SciTech Connect (OSTI)

    Hacke, P.; Smith, R.; Terwiliger, K.; Glick, S.; Jordan, D.; Johnston, S.; Kempe, M.; Kurtz, S.

    2012-07-01

    Acceleration factors are calculated for crystalline silicon PV modules under system voltage stress by comparing the module power during degradation outdoors to that in accelerated testing at three temperatures and 85% relative humidity. A lognormal analysis is applied to the accelerated lifetime test data considering failure at 80% of the initial module power. Activation energy of 0.73 eV for the rate of failure is determined, and the probability of module failure at an arbitrary temperature is predicted. To obtain statistical data for multiple modules over the course of degradation in-situ of the test chamber, dark I-V measurements are obtained and transformed using superposition, which is found well suited for rapid and quantitative evaluation of potential-induced degradation. It is determined that shunt resistance measurements alone do not represent the extent of power degradation. This is explained with a two-diode model analysis that shows an increasing second diode recombination current and ideality factor as the degradation in module power progresses. Failure modes of the modules stressed outdoors are examined and compared to those stressed in accelerated tests.

  8. Thermo-mechanical and neutron lifetime modeling and design of Be pebbles in the neutron multiplier for the LIFE engine

    SciTech Connect (OSTI)

    DeMange, P; Marian, J; de Caro, M S; Caro, A

    2009-03-16

    Concept designs for the laser-initiated fusion/fission engine (LIFE) include a neutron multiplication blanket containing Be pebbles flowing in a molten salt coolant. These pebbles must be designed to withstand the extreme irradiation and temperature conditions in the blanket to enable a safe and cost-effective operation of LIFE. In this work, we develop design criteria for spherical Be pebbles on the basis of their thermomechanical behavior under continued neutron exposure. We consider the effects of high fluence/fast flux on the elastic, thermal and mechanical properties of nuclear-grade Be. Our results suggest a maximum pebble diameter of 30 mm to avoid tensile failure, coated with an anti-corrosive, high-strength metallic shell to avoid failure by pebble contact. Moreover, we find that the operation temperature must always be kept above 450 C to enable creep to relax the stresses induced by swelling, which we estimate to be at least 16 months if uncoated and up to six years when coated. We identify the sources of uncertainty on the properties used and discuss the advantages of new intermetallic beryllides and their use in LIFE's neutron multiplier. To establish Be-pebble lifetimes with improved confidence, reliable experiments to measure irradiation creep must be performed.

  9. Minority carrier lifetime in mid-wavelength infrared InAs/InAsSb superlattices: Photon recycling and the role of radiative and Shockley-Read-Hall recombination mechanisms

    SciTech Connect (OSTI)

    Höglund, L.; Ting, D. Z.; Soibel, A.; Fisher, A.; Khoshakhlagh, A.; Hill, C. J.; Keo, S.; Gunapala, S. D.

    2014-11-10

    The influence of radiative recombination on the minority carrier lifetime in mid-wavelength InAs/InAsSb superlattices was investigated. From the lifetime's dependence on temperature, photon recycling, and carrier concentration, it was demonstrated that radiative lifetime dominates for carrier concentrations >5 × 10{sup 14} cm{sup −3}, and Shockley-Read-Hall recombination starts to dominate the minority carrier lifetime for carrier concentrations <5 × 10{sup 14} cm{sup −3}. An observed increase of the minority carrier lifetime with increasing superlattice thickness was attributed to photon recycling, and good agreement between measured and theoretical values of the photon recycling factor was obtained.

  10. Atmospheric lifetimes and global warming potentials of hydrofluoroethers: Reactivity toward OH, UV spectra, and IR absorption cross sections

    SciTech Connect (OSTI)

    Orkin, V.L.; Villenave, E.; Huie, R.E.; Kurylo, M.J.

    1999-12-02

    The rate constants for the reactions of OH radicals with the fluorinated ethers, CHF{sub 2}-O-CHF{sub 2} (HFOC-134) and CF{sub 3}CH{sub 2}-O-CH{sub 2}CF{sub 3} (HFOC-356mff), were measured using the flash photolysis resonance fluorescence technique over the temperature range 277--370 K to give the following Arrhenius expressions: k{sub HFOC-356mff}(T) = (2.32{sub {minus}0.41}{sup +0.46}) x 10{sup {minus}12} exp{l{underscore}brace}{minus}(790 {+-} 47)/T{r{underscore}brace} cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}. On the basis of the analysis of the available experimental results, the following Arrhenius expression can be recommended for the rate constant of the reaction between OH and HFOC-134: k{sub HFOC-134}(T) = (0.82{sub {minus}0.24}{sup +0.34}) x 10{sup {minus}12} exp{l{underscore}brace}{minus}(1,730 {+-} 110)/T{r{underscore}brace} cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}. Atmospheric lifetimes were estimated to be 24.8 years for HFOC-134 (23.8 years based on the results of this study alone) and 0.3 years for HFOC-356mff. Infrared absorption cross sections of HFOC-134, HFOC-356mff, and HFOC-125 (CHF{sub 2}-O-CF{sub 3}) were measured at T = 295 K from 500 to 1,600 cm{sup {minus}1} and the global warming potentials of the three compounds were estimated. Ultraviolet absorption spectra of the ethers were measured between 160 and 220 nm. The general pattern of reactivity of hydrofluoroethers toward OH is discussed.

  11. In situ monitoring of stacking fault formation and its carrier lifetime mediation in p-type 4H-SiC

    SciTech Connect (OSTI)

    Chen, Bin Chen, Jun; Yao, Yuanzhao; Sekiguchi, Takashi; Matsuhata, Hirofumi; Okumura, Hajime

    2014-07-28

    Using the fine control of an electron beam (e-beam) in scanning electron microscopy with the capabilities of both electrical and optical imaging, the stacking fault (SF) formation together with its tuning of carrier lifetime was in situ monitored and investigated in p-type 4H-SiC homoepitaxial films. The SFs were formed through engineering basal plane dislocations with the energy supplied by the e-beam. The e-beam intensity required for the SF formation in the p-type films was ?100 times higher than that in the n-type ones. The SFs reduced the minority-carrier lifetime in the p-type films, which was opposite to that observed in the n-type case. The reason for the peculiar SF behavior in the p-type 4H-SiC is discussed with the cathodoluminescence results.

  12. $$B^{0}_{s}$$ Lifetime Measurement in the CP-odd Decay Channel $$B^{0}_{s} \\to J/\\psi\\mbox{ }f_{0}(980)$$

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazov, V. M.

    2016-07-06

    Here, the lifetime of the Bs0 meson is measured in the decay channel Bs0→J/ψπ+π- with 880 ≤ Mπ+π- ≤ 1080 MeV/c2, which is mainly a CP-odd state and dominated by the f0(980) resonance. In 10.4 fb-1 of data collected with the D0 detector in Run II of the Tevatron, the lifetime of the Bs0 meson is measured to be τ(Bs0) = 1.70 ± 0.14(stat) ± 0.05(syst) ps. Neglecting CP violation in Bs0/more » $$\\bar{B}$$0s mixing, the measurement can be translated into the width of the heavy mass eigenstate of the Bs0, ΓH = 0.59 ± 0.05(stat) ± 0.02(syst) ps-1.« less

  13. Measurement of the B_d0 lifetime using B_d0 to J/psi K0_S decays at Dzero

    SciTech Connect (OSTI)

    Balm, Paul W

    2004-12-01

    This thesis describes a measurement of the B{sub d}{sup 0} lifetime in the decay to (J/{psi}K{sub S}{sup 0}), using 114 pb{sup -1} of data collected by the D0 experiment at the Tevatron from October 15, 2002, to June 10, 2003. The measurement is motivated by the tests of the Standard Model that it makes possible. These include tests of Heavy Quark Effective Theory predicting B-meson lifetimes, and of the complex phase in the CKM-matrix as the source of CP-violation in B{sub d}{sup 0} decays to (J/{psi}K{sub S}{sup 0}).

  14. Measurement of branching ratio and B0s lifetime in the decay B0s → J/ψ f0(980) at CDF

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aaltonen, T.

    2011-09-30

    We present a study of Bs0 decays to the CP-odd final state J/ψ f0(980) with J/ψ → µ+µ- and f0(980) → π+π-. Using pp̄ collision data with an integrated luminosity of 3.8 fb-1 collected by the CDF II detector at the Tevatron we measure a Bs0 lifetime of τ(B0s → J/ψ f0(980)) = 1.70-0.11+0.12(stat) ± 0.03(syst) ps. This is the first measurement of the Bs0} lifetime in a decay to a CP eigenstate and corresponds in the standard model to the lifetime of the heavy Bs0 eigenstate. We also measure the product of branching fractions of B0s → J/ψ f0(980)more » and f0(980) → π+π- relative to the product of branching fractions of B0s → J/ψφ and φ→K+K- to be Rf0/ψ = 0.257 ± 0.020(stat) ± 0.014(syst), which is the most precise determination of this quantity to date.« less

  15. Lifetime measurement of the metastable 4d {sup 2}D{sub 5/2} state in {sup 88}Sr{sup +} using a single trapped ion

    SciTech Connect (OSTI)

    Letchumanan, V.; Wilson, M.A.; Gill, P.; Sinclair, A.G.

    2005-07-15

    The natural lifetime of the metastable 4d {sup 2}D{sub 5/2} state in {sup 88}Sr{sup +} has been measured using a single laser-cooled, trapped ion. The ion was prepared in the 4d {sup 2}D{sub 5/2} state by laser excitation of the 5s {sup 2}S{sub 1/2}-4d {sup 2}D{sub 5/2} quadrupole transition at 674 nm. The decay time was measured by using Dehmelt's electron shelving method to monitor the ion's electronic state. Two separate investigations were conducted under slightly different experimental conditions. 160 000 decay times from the 4d {sup 2}D{sub 5/2} state were observed in total, and two different methods for determining the statistical value of the measured lifetime have been compared. Systematic effects have also been estimated, and including these effects yields a value of {tau}=390.8(1.6) ms (1{sigma} uncertainty) for the natural lifetime.

  16. Olkiluoto 1 and 2 - Plant efficiency improvement and lifetime extension-project (PELE) implemented during outages 2010 and 2011

    SciTech Connect (OSTI)

    Kosonen, M.; Hakola, M.

    2012-07-01

    Teollisuuden Voima Oyj (TVO) is a non-listed public company founded in 1969 to produce electricity for its stakeholders. TVO is the operator of the Olkiluoto nuclear power plant. TVO follows the principle of continuous improvement in the operation and maintenance of the Olkiluoto plant units. The PELE project (Plant Efficiency Improvement and Lifetime Extension), mainly completed during the annual outages in 2010 and 2011, and forms one part of the systematic development of Olkiluoto units. TVO maintains a long-term development program that aims at systematically modernizing the plant unit systems and equipment based on the latest technology. According to the program, the Olkiluoto 1 and Olkiluoto 2 plant units are constantly renovated with the intention of keeping them safe and reliable, The aim of the modernization projects is to improve the safety, reliability, and performance of the plant units. PELE project at Olkiluoto 1 was done in 2010 and at Olkiluoto 2 in 2011. The outage length of Olkiluoto 1 was 26 d 12 h 4 min and Olkiluoto 2 outage length was 28 d 23 h 46 min. (Normal service-outage is about 14 days including refueling and refueling-outage length is about seven days. See figure 1) The PELE project consisted of several single projects collected into one for coordinated project management. Some of the main projects were as follows: - Low pressure turbines: rotor, stator vane, casing and turbine instrumentation replacement. - Replacement of Condenser Cooling Water (later called seawater pumps) pumps - Replacement of inner isolation valves on the main steam lines. - Generator and the generator cooling system replacement. - Low voltage switchgear replacement. This project will continue during future outages. PELE was a success. 100 TVO employees and 1500 subcontractor employees participated in the project. The execution of the PELE projects went extremely well during the outages. The replacement of the low pressure turbines and seawater pumps improved the

  17. Minority carrier lifetime and dark current measurements in mid-wavelength infrared InAs0.91Sb0.09 alloy nBn photodetectors

    SciTech Connect (OSTI)

    Olson, B. V.; Kim, J. K.; Kadlec, E. A.; Klem, J. F.; Hawkins, S. D.; Leonhardt, D.; Coon, W. T.; Fortune, T. R.; Cavaliere, M. A.; Tauke-Pedretti, A.; Shaner, E. A.

    2015-11-03

    Carrier lifetime and dark current measurements are reported for a mid-wavelength infrared InAs 0.91Sb0.09 alloy nBn photodetector. Minority carrier lifetimes are measured using a non-contact time-resolved microwave technique on unprocessed portions of the nBn wafer and the Auger recombination Bloch function parameter is determined to be |F1F2|=0.292. Moreover, the measured lifetimes are also used to calculate the expected diffusion dark current of the nBn devices and are compared with the experimental dark current measured in processed photodetector pixels from the same wafer. As a result, excellent agreement is found between the two, highlighting the important relationship between lifetimes and diffusion currents in nBn photodetectors.

  18. Lasing action and extraordinary reduction in long radiative lifetime of type-II GaSb/GaAs quantum dots using circular photonic crystal nanocavity

    SciTech Connect (OSTI)

    Hsu, Kung-Shu; Chang, Shu-Wei; Hung, Wei-Chun; Chang, Chih-Chi; Lin, Wei-Hsun; Lin, Shih-Yen; Shih, Min-Hsiung; Lee, Po-Tsung; Chang, Yia-Chung

    2015-08-31

    We demonstrated the lasing action and remarkable reduction in long radiative lifetimes of type-II GaSb/GaAs quantum dots using a circular photonic-crystal nano-cavity with high Purcell factors. The associated enhancement in carrier recombination was surprisingly high and could even surpass type-I counterparts in similar conditions. These phenomena reveal that the type-II sample exhibited extremely low nonradiative recombination so that weak radiative transitions were more dominant than expected. The results indicate that type-II nanostructures may be advantageous for applications which require controllable radiative transitions but low nonradiative depletions.

  19. SOLERAS - Solar Controlled Environment Agriculture Project. Final report, Volume 1. Project summary

    SciTech Connect (OSTI)

    Not Available

    1985-12-30

    A summary of the Solar Controlled Environment Agriculture Project is presented. The design of the greenhouses include transparent double pane glass roof with channels for fluid between the panes, inner pane tinted and double pane extruded acrylic aluminized mylar shade and diffuser. Solar energy technologies provide power for water desalination, for pumping irrigation water, and for cooling and heating the controlled environment space so that crops can grow in arid lands. The project is a joint effort between the United States and Saudi Arabia. (BCS)

  20. Lifetime of the K{sup pi} = 8{sup -} isomer in the neutron-rich nucleus, {sup 174}Er and N = 106 E1 systematics.

    SciTech Connect (OSTI)

    Dracoulis, G. D.; Lane, G. J.; Kondev, F. G.; Watanabe, H.; Seweryniak, D.; Zhu, S.; Carpenter, M. P.; Chiara, C. J.; Janssens, R. V. F.; Lauritsen, T.; Lister, C. J.; McCutchan, E. A.; Stefanescu, I.; Australian National Univ.; RIKEN; Univ. of Maryland

    2009-06-01

    Chopped-beam techniques and {gamma}-ray spectroscopy with Gammasphere have been used to measure the lifetime of the 1112-keV 8{sup -} isomeric state in {sup 174}Er. The value obtained of {tau} = 5.8(4) s corresponds to a reduced hindrance of f{sub {nu}} = 98 for the 163-keV E1 transition to the 8{sup +} state of the ground-state band, in good agreement with the systematics of the corresponding E1 strengths in the N = 106 isotones. The K-mixing in the 8{sup -} states is calculated in the context of the particle-rotor model and used to extract the underlying reduced hindrances.

  1. Lifetime of the K{sup {pi}}=8{sup -} isomer in the neutron-rich nucleus {sup 174}Er, and N=106 E1 systematics

    SciTech Connect (OSTI)

    Dracoulis, G. D.; Lane, G. J.; Kondev, F. G.; Chiara, C. J.; Watanabe, H.; Seweryniak, D.; Zhu, S.; Carpenter, M. P.; Janssens, R. V. F.; Lauritsen, T.; Lister, C. J.; McCutchan, E. A.; Stefanescu, I.

    2009-06-15

    Chopped-beam techniques and {gamma}-ray spectroscopy with Gammasphere have been used to measure the lifetime of the 1112-keV 8{sup -} isomeric state in {sup 174}Er. The value obtained of {tau}=5.8(4) s corresponds to a reduced hindrance of f{sub {nu}}=98 for the 163-keV E1 transition to the 8{sup +} state of the ground-state band, in good agreement with the systematics of the corresponding E1 strengths in the N=106 isotones. The K-mixing in the 8{sup -} states is calculated in the context of the particle-rotor model and used to extract the underlying reduced hindrances.

  2. Distinct roles of the photosystem II protein PsbS and zeaxanthin in the regulation of light harvesting in plants revealed by fluorescence lifetime snapshots

    SciTech Connect (OSTI)

    Sylak-Glassman, Emily J.; Malnoë, Alizée; De Re, Eleonora; Brooks, Matthew D.; Fischer, Alexandra Lee; Niyogi, Krishna K.; Fleming, Graham R.

    2014-10-01

    The photosystem II (PSII) protein PsbS and the enzyme violaxanthin deepoxidase (VDE) are known to influence the dynamics of energy-dependent quenching (qE), the component of nonphotochemical quenching (NPQ) that allows plants to respond to fast fluctuations in light intensity. Although the absence of PsbS and VDE has been shown to change the amount of quenching, there have not been any measurements that can detect whether the presence of these proteins alters the type of quenching that occurs. The chlorophyll fluorescence lifetime probes the excited-state chlorophyll relaxation dynamics and can be used to determine the amount of quenching as well as whether two different genotypes with the same amount of NPQ have similar dynamics of excited-state chlorophyll relaxation. We measured the fluorescence lifetimes on whole leaves of Arabidopsis thaliana throughout the induction and relaxation of NPQ for wild type and the qE mutants, npq4, which lacks PsbS; npq1, which lacks VDE and cannot convert violaxanthin to zeaxanthin; and npq1 npq4, which lacks both VDE and PsbS. These measurements show that although PsbS changes the amount of quenching and the rate at which quenching turns on, it does not affect the relaxation dynamics of excited chlorophyll during quenching. In addition, the data suggest that PsbS responds not only to ΔpH but also to the Δψ across the thylakoid membrane. In contrast, the presence of VDE, which is necessary for the accumulation of zeaxanthin, affects the excited-state chlorophyll relaxation dynamics.

  3. Distinct roles of the photosystem II protein PsbS and zeaxanthin in the regulation of light harvesting in plants revealed by fluorescence lifetime snapshots

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sylak-Glassman, Emily J.; Malnoë, Alizée; De Re, Eleonora; Brooks, Matthew D.; Fischer, Alexandra Lee; Niyogi, Krishna K.; Fleming, Graham R.

    2014-10-01

    The photosystem II (PSII) protein PsbS and the enzyme violaxanthin deepoxidase (VDE) are known to influence the dynamics of energy-dependent quenching (qE), the component of nonphotochemical quenching (NPQ) that allows plants to respond to fast fluctuations in light intensity. Although the absence of PsbS and VDE has been shown to change the amount of quenching, there have not been any measurements that can detect whether the presence of these proteins alters the type of quenching that occurs. The chlorophyll fluorescence lifetime probes the excited-state chlorophyll relaxation dynamics and can be used to determine the amount of quenching as well asmore » whether two different genotypes with the same amount of NPQ have similar dynamics of excited-state chlorophyll relaxation. We measured the fluorescence lifetimes on whole leaves of Arabidopsis thaliana throughout the induction and relaxation of NPQ for wild type and the qE mutants, npq4, which lacks PsbS; npq1, which lacks VDE and cannot convert violaxanthin to zeaxanthin; and npq1 npq4, which lacks both VDE and PsbS. These measurements show that although PsbS changes the amount of quenching and the rate at which quenching turns on, it does not affect the relaxation dynamics of excited chlorophyll during quenching. In addition, the data suggest that PsbS responds not only to ΔpH but also to the Δψ across the thylakoid membrane. In contrast, the presence of VDE, which is necessary for the accumulation of zeaxanthin, affects the excited-state chlorophyll relaxation dynamics.« less

  4. Measurement of the Λb⁰ lifetime in the exclusive decay Λb⁰→J/ψΛ⁰ in pp̄ collisions at √s=1.96 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Aoki, M.; et al

    2012-06-07

    We measure the Λ⁰b lifetime in the fully reconstructed decay Λ⁰b→J/ψΛ⁰ using 10.4 fb⁻¹ of pp̄ collisions collected with the D0 detector at √s=1.96 TeV. The lifetime of the topologically similar decay channel B⁰→J/ψK⁰S is also measured. We obtain τ(Λ⁰b)=1.303±0.075(stat)±0.035(syst) ps and τ(B⁰)=1.508±0.025(stat)±0.043(syst) ps. Using these measurements, we determine the lifetime ratio of τ(Λ⁰b)/τ(B⁰)=0.864±0.052(stat)±0.033(syst).

  5. Demonstration of the Performance of Highly Insulating (R-5) Windows in a Matched Pair of Homes

    SciTech Connect (OSTI)

    Widder, Sarah H.; Parker, Graham B.

    2013-12-05

    Improving the insulation and solar heat gain characteristics of a homes windows has the potential to significantly improve the homes overall thermal performance by reducing heat loss (in the winter), and cooling loss and solar heat gain (in the summer) through the windows. A high-quality installation will also minimize or reduce air leakage through the building envelope, decreasing infiltration and thus contributing to reduced heat transmission through building envelope. These improvements all contribute to decreasing overall annual home energy use. In addition to improvements in energy efficiency, highly insulating windows can have important impacts on occupant comfort by minimizing or eliminating the cold draft many homeowners experience at or near window surfaces that are at a noticeably cooler than the room air temperature. Energy efficiency measures, such as highly insulating windows, also have the potential to decrease peak energy use in a home, which can lead to measurable peak load decreases for a utility service territory if implemented on a large scale. High-performance windows now feature triple-pane glass, double low-e coatings, and vinyl insulated frames to achieve U-factors as low as 0.2 , as compared to double-pane clear glass windows with a U-factor of 0.67, which are common in existing homes across the United States. The highly insulating windows (as they will be referred to in this document) are now available from several manufacturers and show promise to yield considerable energy savings and thermal comfort improvements in homes.

  6. Measurement of the Bs0 Lifetime in Fully and Partially Reconstructed Bs0 -> Ds- (phi pi-)X Decays in pp¯ Collisions at √s = 1.96 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aaltonen, T.

    2011-12-29

    The authors present a measurement of the Bs0 lifetime in fully and partially reconstructed Bs0 = Ds0(φπ-)X decays in 1.3 fb-1 collected in pp¯ collisions at √s = 1.96 Tev by the CDF II detector at the Fermilab Tevatron. They measure τ(Bs0) = 1.518 ± 0.041 (stat.) ± 0.027 (syst.) ps. The ratio of this result and the world average B0 lifetime yields τ(Bs0)/τ(B0) = 0.99 ± 0.03, which is in agreement with recent theoretical predictions.

  7. Measurement of the Bs0 Lifetime in Fully and Partially Reconstructed Bs0 -> Ds- (phi pi-)X Decays in pp? Collisions at ?s = 1.96 TeV

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Aaltonen, T.

    2011-12-29

    The authors present a measurement of the Bs0 lifetime in fully and partially reconstructed Bs0 = Ds0(??-)X decays in 1.3 fb-1 collected in pp? collisions at ?s = 1.96 Tev by the CDF II detector at the Fermilab Tevatron. They measure ?(Bs0) = 1.518 0.041 (stat.) 0.027 (syst.) ps. The ratio of this result and the world average B0 lifetime yields ?(Bs0)/?(B0) = 0.99 0.03, which is in agreement with recent theoretical predictions.

  8. New lifetime measurements in Pd109 and the onset of deformation at N=60

    SciTech Connect (OSTI)

    Bucher, B.; Mach, H.; Aprahamian, A.; Simpson, G. S.; Rissanen, J.; Ghiţă, D. G.; Olaizola, B.; Kurcewicz, W.; Äystö, J.; Bentley, I.; Eronen, T.; Fraile, L. M.; Jokinen, A.; Karvonen, P.; Moore, I. D.; Penttilä, H.; Reponen, M.; Ruchowska, E.; Saastamoinen, A.; Smith, M. K.; Weber, C.

    2015-12-14

    We measured several new subnanosecond lifetimes in 109Pd using the fast-timing βγ γ (t ) method. Fission fragments of the A = 109 mass chain were produced by bombarding natural uranium with 30 MeV protons at the Jyväskylä Ion Guide Isotope Separator On-Line (IGISOL) facility. We obtained lifetimes for excited states in 109Pd populated following β decay of 109Rh. The new lifetimes provide some insight into the evolution of nuclear structure in this mass region. In particular, the distinct structure of the two low-lying 7/2+ states occurring systematically across the Pd isotopic chain is supported by the new lifetime measurements. Finally, the available nuclear data indicate a sudden increase in deformation at N = 60 which is related to the strong p-n interaction between πg9/2 and νg7/2 valence nucleons expected in this region.

  9. Lifetime difference in the Bs0 system from untagged Bs0 ---> J/psi phi decay at s**(1/2) = 1.96 TeV at D0 detector

    SciTech Connect (OSTI)

    Chandra, Avdhesh; /Tata Inst.

    2006-11-01

    In this dissertation, they present a study of the untagged decay of B{sub s}{sup 0} {yields} J/{psi}{phi}, the final state of which is a superposition of the CP-even and CP-odd states. Within the framework of the standard model (SM), to a good approximation, the two CP eigenstates of the (B{sub s}{sup 0}, {bar B}{sub s}{sup 0}) system are equivalent to mass eigenstates. The data collected by the D0 detector between June 2002 to August 2004 (an integrated luminosity of approximately 450 pb{sup -1}) has been used for the analysis presented in this thesis. From a simultaneous fit to the B{sub s}{sup 0} candidate mass, lifetime, and the angular distribution of the decay products, they obtain the CP-odd fraction in the final state at production time to be 0.16 {+-} 0.10(stat) {+-} 0.02(syst). The average lifetime of the (B{sub s}{sup 0}, {bar B}{sub s}{sup 0}) system is measured to be 1.39{sub -0.16}{sup +0.13}(stat){sub -0.02}{sup +0.01}(syst) ps, with the relative width difference between the heavy and light mass eigenstates, {Delta}{Gamma}/{bar {Gamma}} = ({Gamma}{sup L}/{Gamma}{sup H})/{bar {Gamma}} = 0.24{sub -0.38}{sup +0.28}(stat){sub -0.04}{sup +0.03}(syst). With the additional constraint from the world average of the B{sub s}{sup 0} lifetime measurements using semileptonic decays, they find average lifetime of the (B{sub s},{sup 0}, {bar B}{sub s}{sup 0}) system 1.39 {+-} 0.06 ps with {Delta}{Gamma}/{bar {Gamma}} = 0.25{sub -0.15}{sup +0.14}. They have also done B{sup 0} lifetime measurement for its analogous decay mode to J/{psi}K*. With this measurement they get B{sup 0} lifetime 1.530 {+-} 0.043(stat) {+-} 0.023(syst) ps. Using above results, they get 0.91 {+-} 0.09(stat) {+-} 0.003(syst), for the ratio of the B{sub s}{sup 0} and B{sup 0} lifetimes ({bar {Gamma}}(B{sub s}{sup 0})/{Gamma}(B{sup 0})). These measurements are consistent with the predictions of SM within the measurement uncertainty.

  10. PEVELOPMENT OF FLUORESCENCE LIFETIME DIAGNOSTIC

    Office of Scientific and Technical Information (OSTI)

    chemistry and instrumentation. LLNL's fiber- optic sensor group had significant expertise in these areas, but had previously concentrated its efforts on the chemistry, ...