National Library of Energy BETA

Sample records for om pu te

  1. Te

    Gasoline and Diesel Fuel Update (EIA)

    C o l o m b i e - B r i t a n n i q u e E l l e s m e r e I s l a n d Í l e d u E l l e s m e r e N o u v e a u B r u n s w i c k Q u é b e c Î l e - d u P r i n c e - É d o u a r d N o u v e l l e - É c o s s e N e w f o u n d l a n d a n d L a b r a d o r Te r r e - N e u v e e t - L a b r a d o r A l a s k a N u n a v u t O n t a r i o A l b e r t a Te x a s N o r t h w e s t Te r r i t o r i e s M a n i t o b a B r i t i s h C o l u m b i a S a s k a t c h e w a n Y u k o n M o n t a n

  2. Te

    Gasoline and Diesel Fuel Update (EIA)

    Í l e d u E l l e s m e r e N e w f o u n d l a n d a n d L a b r a d o r Te r r e - N e u v e - e t - L a b r a d o r 22 A l a s k a N u n a v u t O n t a r i o A l b e r t a Te x a s N o r t h w e s t Te r r i t o r i e s M a n i t o b a B r i t i s h C o l u m b i a S a s k a t c h e w a n Y u k o n M o n t a n a U t a h I d a h o C a l i f o r n i a N e v a d a O r e g o n A r i z o n a I o w a K a n s a s C o l o r a d o W y o m i n g S o n o r a N e w M e x i c o M i n n e s o t a N e b r

  3. Te

    Gasoline and Diesel Fuel Update (EIA)

    N u n a v u t O n t a r i o A l b e r t a Te x a s N o r t h w e s t Te r r i t o r i e s M a n i t o b a B r i t i s h C o l u m b i a S a s k a t c h e w a n Y u k o n M o n t a n a U t a h I d a h o C a l i f o r n i a N e v a d a O r e g o n A r i z o n a I o w a K a n s a s C o l o r a d o W y o m i n g S o n o r a N e w M e x i c o M i n n e s o t a N e b r a s k a O h i o C h i h u a h u a I l l i n o i s M i s s o u r i F l o r i d a G e o r g i a O k l a h o m a W a s h i n g t o n S o

  4. Te

    Gasoline and Diesel Fuel Update (EIA)

    A l a s k a N u n a v u t O n t a r i o A l b e r t a Te x a s N o r t h w e s t Te r r i t o r i e s M a n i t o b a B r i t i s h C o l u m b i a S a s k a t c h e w a n Y u k o n M o n t a n a U t a h I d a h o C a l i f o r n i a N e v a d a O r e g o n A r i z o n a I o w a K a n s a s C o l o r a d o W y o m i n g S o n o r a N e w M e x i c o M i n n e s o t a N e b r a s k a O h i o C h i h u a h u a I l l i n o i s M i s s o u r i F l o r i d a G e o r g i a O k l a h o m a W a s h i n

  5. Te

    Gasoline and Diesel Fuel Update (EIA)

    D u N o r d - O u e s t Te r r e - N e u v e - e t - L a b r a d o r Q u é b e c Í l e - d u - P r i n c e - É d o u a r d N o u v e l l e - É c o s s e N o u v e a u - B r u n s w i c k C o l o m b i e - B r i t a n n i q u e B a f f i n I s l a n d Í l e d u B a f f i n E l l e s m e r e I s l a n d Í l e d u E l l e s m e r e V i c t o r i a I s l a n d Í l e d u V i c t o r i a N e w f o u n d l a n d a n d L a b r a d o r Te r r e - N e u v e - e t - L a b r a d o r A l a s k a N u n

  6. ARM - Instrument - om

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

    govInstrumentsom Documentation Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Instrument : Ozone Monitoring Instrument (OM) <!-- Picture of the Ozone Monitoring Instrument (OMI) --> General Overview The Ozone Monitoring Instrument (OMI) distinguishes between aerosol types, such as smoke, dust, and sulfates, and can measure cloud pressure and coverage, which provide data to derive tropospheric ozone. OMI continues the TOMS record for total

  7. ERYLFIUM OM PANY

    Office of Legacy Management (LM)

    ERYLFIUM OM PANY 3714 CI-XIESTER /%"EXUE J &CO-74 -L;s C+SSIFICATION CANCELLED OR April 22, 1947 Dear 3. 3elmore: Xith reference to Contract X- 7401 ens 78, supp1emstit 11 calJi?Jg for 5000 pounds of SP ?eO 1350X, we have shipped 5000 pounds to the A. C. Spark E' lU~ co. in i?int i~i0hige.n. There were two s!lipi%ents made against this order. GE/L Kc. The first shipmast was ;lade on i.i)ril 12, ,A947 via ~rnili7c.y eqress on K,' -23305 copies .;; -"5 and ~$7 of which are enclosed.

  8. Pu-238 Fact Sheet

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

    and Determination for Pu-238 Production Radioisotope power systems enable space exploration and national security missions. T he Department of Energy (DOE) and its predecessors have pro- vided radioisotope power systems that have safely enabled deep space exploration and national security missions for five decades. Radioisotope power systems (RPSs) convert the heat from the decay of the plutonium-238 (Pu-238) isotope into electricity. RPSs are capable of producing heat and electricity under the

  9. Changes of O/M, dimension and microstructure of MOX pellet during heat treatment

    SciTech Connect (OSTI)

    Watanabe, M.; Kato, M.; Sunaoshi, T.

    2013-07-01

    The oxidation and reduction behaviors of sintered (Pu{sub 0.3}U{sub 0.7})O{sub 2-x} pellets have been studied at 1873 K under a controlled oxygen partial pressure. From the results of oxygen-to-metal (O/M) ratio changes, dimensional and structural changes, it was concluded that the crack nucleation-propagation and the local density change of pores were caused by the tensile and compressive stresses due to the O/M ratio distribution in the direction of the pellet radius. (authors)

  10. Pu Qian | Photosynthetic Antenna Research Center

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

    Pu Qian Pu Qian placeholder image Pu Qian Postdoctoral Associate E-mail: p.qian@sheffield.ac.uk Postdoctoral Associates

  11. OM300 Direction Drilling Module

    SciTech Connect (OSTI)

    MacGugan, Doug

    2013-08-22

    OM300 – Geothermal Direction Drilling Navigation Tool: Design and produce a prototype directional drilling navigation tool capable of high temperature operation in geothermal drilling Accuracies of 0.1° Inclination and Tool Face, 0.5° Azimuth Environmental Ruggedness typical of existing oil/gas drilling Multiple Selectable Sensor Ranges High accuracy for navigation, low bandwidth High G-range & bandwidth for Stick-Slip and Chirp detection Selectable serial data communications Reduce cost of drilling in high temperature Geothermal reservoirs Innovative aspects of project Honeywell MEMS* Vibrating Beam Accelerometers (VBA) APS Flux-gate Magnetometers Honeywell Silicon-On-Insulator (SOI) High-temperature electronics Rugged High-temperature capable package and assembly process

  12. O/M RATIO MEASUREMENT IN PURE AND MIXED OXIDE FULES - WHERE ARE WE NOW?

    SciTech Connect (OSTI)

    J. RUBIN; ET AL

    2000-12-01

    The oxygen-to-metal (O/M) ratio is one of the most critical parameters of nuclear fuel fabrication, and its measurement is closely monitored for manufacturing process control and to ensure the service behavior of the final product. Thermogravimetry is the most widely used method, the procedure for which has remained largely unchanged since its development some thirty years ago. It was not clear to us, however, that this method is still the optimum one in light of advances in instrumentation, and in the current regulatory environment, particularly with regard to waste management and disposal. As part of the MOX fuel fabrication program at Los Alamos, we conducted a comprehensive review of methods for O/M measurements in UO{sub 2}, PuO{sub 2} and mixed oxide fuels for thermal reactors. A concerted effort was made to access information not available in the open literature. We identified approximately thirty five experimental methods that (a) have been developed with the intent of measuring O/M, (b) provided O/M indirectly by suitable reduction of the measured data, or (c) could provide O/M data with suitable data reduction or when combined with other methods. We will discuss the relative strengths and weaknesses of these methods in their application to current routine and small-lot production environment.

  13. Elastic properties of Pu metal and Pu-Ga alloys

    SciTech Connect (OSTI)

    Soderlind, P; Landa, A; Klepeis, J E; Suzuki, Y; Migliori, A

    2010-01-05

    We present elastic properties, theoretical and experimental, of Pu metal and Pu-Ga ({delta}) alloys together with ab initio equilibrium equation-of-state for these systems. For the theoretical treatment we employ density-functional theory in conjunction with spin-orbit coupling and orbital polarization for the metal and coherent-potential approximation for the alloys. Pu and Pu-Ga alloys are also investigated experimentally using resonant ultrasound spectroscopy. We show that orbital correlations become more important proceeding from {alpha} {yields} {beta} {yields} {gamma} plutonium, thus suggesting increasing f-electron correlation (localization). For the {delta}-Pu-Ga alloys we find a softening with larger Ga content, i.e., atomic volume, bulk modulus, and elastic constants, suggest a weakened chemical bonding with addition of Ga. Our measurements confirm qualitatively the theory but uncertainties remain when comparing the model with experiments.

  14. Spring O&M Users Group Meeting

    Broader source: Energy.gov [DOE]

    The spring 2015 UVIG O&M User Group meeting will feature a plenary session focused on blade inspection best practices.  The UVIG membership will hear presentations from:

  15. Pu Anion Exchange Process Intensification

    SciTech Connect (OSTI)

    Taylor-Pashow, K.

    2015-10-08

    This project seeks to improve the efficiency of the plutonium anion-exchange process for purifying Pu through the development of alternate ion-exchange media. The objective of the project in FY15 was to develop and test a porous foam monolith material that could serve as a replacement for the current anion-exchange resin, Reillex HPQ, used at the Savannah River Site (SRS) for purifying Pu. The new material provides advantages in efficiency over the current resin by the elimination of diffusive mass transport through large granular resin beads. By replacing the large resin beads with a porous foam there is much more efficient contact between the Pu solution and the anion-exchange sites present on the material. Several samples of a polystyrene based foam grafted with poly(4-vinylpyridine) were prepared and the Pu sorption was tested in batch contact tests.

  16. Properties measurements of (U{sub 0.7}Pu{sub 0.3})O{sub 2-x} in PO{sub 2}-controlled atmosphere

    SciTech Connect (OSTI)

    Kato, M.; Murakami, T.; Sunaoshi, T.; Nelson, A.T.; McClellan, K.J.

    2013-07-01

    The investigation of physical properties of uranium and plutonium mixed oxide (MOX) fuels is important for the development of fast reactor fuels. It is well known that MOX is a nonstoichiometric oxide, and the physical properties change drastically with the Oxygen-to-Metal (O/M) ratio. A control technique for O/M ratio was established for measurements of high temperature properties of uranium and plutonium mixed oxide fuels. Sintering behavior, thermal expansion and O/M change of (U{sub 0.7}Pu{sub 0.3})O{sub 2.00} and (U{sub 0.7}Pu{sub 0.3})O{sub 1.99} were investigated in PO{sub 2}-controlled atmosphere which was controlled by H{sub 2}/H{sub 2}O gas system. Sintering behavior changed drastically with O/M ratio, and shrinkage of (U{sub 0.7}Pu{sub 0.3})O{sub 2.00} was faster and more advanced at lower temperatures as compared with (U{sub 0.7}Pu{sub 0.3})O{sub 1.99}. Thermal expansion was observed to be slightly increased with decreasing O/M ratio. (authors)

  17. Economical Production of Pu-238

    SciTech Connect (OSTI)

    Steven D. Howe; Douglas Crawford; Jorge Navarro; Terry Ring

    2013-02-01

    All space exploration missions traveling beyond Jupiter must use radioisotopic power sources for electrical power. The best isotope to power these sources is plutonium-238. The US supply of Pu-238 is almost exhausted and will be gone within the next decade. The Department of Energy has initiated a production program with a $10M allocation from NASA but the cost is estimated at over $100 M to get to production levels. The Center for Space Nuclear Research has conceived of a potentially better process to produce Pu-238 earlier and for significantly less cost. The new process will also produce dramatically less waste. Potentially, the front end costs could be provided by private industry such that the government only had to pay for the product produced. Under a NASA Phase I NIAC grant, the CSNR has evaluated the feasibility of using a low power, commercially available nuclear reactor to produce at least 1.5 kg of Pu-238 per year. The impact on the neutronics of the reactor have been assessed, the amount of Neptunium target material estimated, and the production rates calculated. In addition, the size of the post-irradiation processing facility has been established. In addition, a new method for fabricating the Pu-238 product into the form used for power sources has been identified to reduce the cost of the final product. In short, the concept appears to be viable, can produce the amount of Pu-238 needed to support the NASA missions, can be available within a few years, and will cost significantly less than the current DOE program.

  18. AWEA Wind Project O&M and Safety Seminar

    Broader source: Energy.gov [DOE]

    The AWEA Wind Project O&M and Safety Seminar is where leading owners, operators, turbine manufacturers, material suppliers, wind technicians, managers, supervisors, engineers, and occupational...

  19. Elasticity of Pu -a window into fundamental understanding and...

    Office of Scientific and Technical Information (OSTI)

    Elasticity of Pu -a window into fundamental understanding and aging Citation Details In-Document Search Title: Elasticity of Pu -a window into fundamental understanding and aging...

  20. Om Sakthi Wind Power Pvt Ltd | Open Energy Information

    Open Energy Info (EERE)

    Sakthi Wind Power Pvt Ltd Jump to: navigation, search Name: Om Sakthi Wind Power Pvt. Ltd. Place: Chennai, Tamil Nadu, India Sector: Wind energy Product: Chennai-based wind project...

  1. OM Code Requirements For MOVs -- OMN-1 and Appendix III

    SciTech Connect (OSTI)

    Kevin G. DeWall

    2011-08-01

    The purpose or scope of the ASME OM Code is to establish the requirements for pre-service and in-service testing of nuclear power plant components to assess their operational readiness. For MOVs this includes those that perform a specific function in shutting down a reactor to the safe shutdown condition, maintaining the safe shutdown condition, and mitigating the consequences of an accident. This paper will present a brief history of industry and regulatory activities related to MOVs and the development of Code requirements to address weaknesses in earlier versions of the OM Code. The paper will discuss the MOV requirements contained in the 2009 version of ASME OM Code, specifically Mandatory Appendix III and OMN-1, Revision 1.

  2. AWEA O&M Recommended Practices Series Part VII: Wind Turbine...

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

    AWEA O&M Recommended Practices Series Part VII: Wind Turbine Gear Lubricant Flushing Procedures AWEA O&M Recommended Practices Series Part VII: Wind Turbine Gear Lubricant Flushing...

  3. Pu-bearing materials - from fundamental science to storage standards.

    SciTech Connect (OSTI)

    Tam, S. W.; Liu, Y.; Decision and Information Sciences; Michigan Technical Univ.

    2008-01-01

    The behavior of plutonium (Pu) oxides in the presence of water/moisture in a confined space and the associated issues of hydrogen and oxygen generation due to radiolysis have important implications for the storage and transportation of Pu-bearing materials. This paper reviews the results of recent studies of gas generation in the Pu-O-H system, including the determination of release rates via engineering-scale measurement. The observations of the significant differences in gas generation behavior between 'pure' Pu-bearing materials and those that contain salt impurities are addressed. In conjunction with the discussion of these empirical observations, the work also addresses recent scientific advances in the investigations of the Pu-O-H system using state-of-the-art ab initio electronic structure calculations, as well as advanced synchrotron techniques to determine the electronic structure of the various Pu-containing phases. The role of oxidizing species such as the hydroxyl radical from the radiolysis of water is examined. Discussed also is the challenge in the predictive ab-initio calculations of the electronic structure of the Pu-H-O system, due to the nature of the 5f valence electrons in Pu. Coupled with the continuing material surveillance program, it is anticipated that this work may help determine the electronic structure of the various Pu-containing phases and the role of impurity salts on gas generation and the long-term stability of oxygen/hydrogen-containing plutonium oxides beyond PuO{sub 2}.

  4. A=3n (2010PU04)

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

    2010PU04) GENERAL: There is no experimental evidence for either bound states or narrow resonances of the three neutron system. Theoretical studies in the 3n system using the Faddeev method and fairly realistic two-body interactions have been carried out for complex energies looking for evidence of resonances; see (1999WI08, 2002HE25). The conclusion in each case is that such resonances probably do not exist close to the physical region. However, a similar study reported in (1996CS02) concluded

  5. Nuclear magnetic resonance offers new insights into Pu 239

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

    Nuclear magnetic resonance offers new insights into Pu 239 Nuclear magnetic resonance offers new insights into Pu 239 Fingerprint of element found by LANL/Japanese team. May 29, 2012 How would the detonation of a nuclear energy source afffect an incoming asteroid? Georgios Koutroulakis and H. Yasuoka in the condensed-matter NMR lab at Los Alamos National Laboratory after having observed the magnetic resonance signal of Pu 239 for the first time. Get Expertise Scientist Eric Bauer Condensed

  6. 125Te NMR chemical-shift trends in PbTeGeTe and PbTeSnTe alloys

    SciTech Connect (OSTI)

    Njegic, Bosiljka; Levin, Evgenii M.; Schmidt-Rohr, Klaus

    2013-10-08

    Complex tellurides, such as doped PbTe, GeTe, and their alloys, are among the best thermoelectric materials. Knowledge of the change in 125Te NMR chemical shift due to bonding to dopant or solute atoms is useful for determination of phase composition, peak assignment, and analysis of local bonding. We have measured the 125Te NMR chemical shifts in PbTe-based alloys, Pb1?xGexTe and Pb1?xSnxTe, which have a rocksalt-like structure, and analyzed their trends. For low x, several peaks are resolved in the 22-kHz MAS 125Te NMR spectra. A simple linear trend in chemical shifts with the number of Pb neighbors is observed. No evidence of a proposed ferroelectric displacement of Ge atoms in a cubic PbTe matrix is detected at low Ge concentrations. The observed chemical shift trends are compared with the results of DFT calculations, which confirm the linear dependence on the composition of the first-neighbor shell. The data enable determination of the composition of various phases in multiphase telluride materials. They also provide estimates of the 125Te chemical shifts of GeTe and SnTe (+970 and +400150 ppm, respectively, from PbTe), which are otherwise difficult to access due to Knight shifts of many hundreds of ppm in neat GeTe and SnTe.

  7. Report on the Feasibility of Pu Photoelectron Spectroscopy with...

    Office of Scientific and Technical Information (OSTI)

    Report on the Feasibility of Pu Photoelectron Spectroscopy with Microscopic and Nanoscopic Samples at NSLSII Citation Details In-Document Search Title: Report on the Feasibility of...

  8. Procedure for plutonium determination using Pu(VI) spectra

    SciTech Connect (OSTI)

    Walker, L.F.; Temer, D.J.; Jackson, D.D.

    1996-09-01

    This document describes a simple spectrophotometric method for determining total plutonium in nitric acid solutions based on the spectrum of Pu(VI). Plutonium samples in nitric acid are oxidized to Pu(VI) with Ce(IV) and the net absorbance at the 830 nm peak is measured.

  9. A=3H (2010PU04)

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

    2010PU04) GENERAL: Ground State: Jπ = 1/2+ μ = 2.978960 ± 0.000001 μN Mass Excess, M - A = 14.9498060 ± 0.0000023 MeV T1/2 = 12.32 ± 0.02 y = 4500 ± 8 days Decay Mode: β- decay Binding Energy, EB = 8.481798 ± 0.000002 MeV Neutron Separation Energy, Sn = 6.257233 ± 0.000002 MeV The ground state wave functions for 3H and 3He consist mainly of a spatially symmetric S state (about 90%), a mixed symmetry S' state (about 1%), a D state (about 9%) and a small P state (less than 0.1%). Some

  10. A=3He (2010PU04)

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

    2010PU04) GENERAL: Ground State: Jπ = 1/2+ μ = -2.127497718 ± 0.000000025 μN Mass Excess, M - A = 14.93121475 ± 0.00000242 MeV Decay Mode: stable Binding Energy, EB = 7.718043 ± 0.000002 MeV Proton Separation Energy, Sp = 5.493478 ± 0.000002 MeV A topic of interest in connection with the mass 3 nuclei is the difference in binding energies of 3H and 3He and the relationship of this difference to charge symmetry breaking (CSB). The binding energy of 3H is larger than that of 3He by a little

  11. Performance of Cladding on MOX Fuel with Low 240Pu/239Pu Ratio

    SciTech Connect (OSTI)

    McCoy, Kevin; Blanpain, Patrick; Morris, Robert Noel

    2014-01-01

    The U.S. Department of Energy has decided to dispose of a portion of its surplus plutonium by reconstituting it into mixed oxide (MOX) fuel and irradiating it in commercial power reactors. As part of fuel qualification, four lead assemblies were manufactured and irradiated to a maximum fuel rod average burnup of 47.3 MWd/kg heavy metal. This was the world s first commercial irradiation of MOX fuel with a 240Pu/239Pu ratio less than 0.10. Five fuel rods with varying burnups and plutonium contents were selected from one of the assemblies and shipped to Oak Ridge National Laboratory for hot cell examination. This paper discusses the results of those examinations with emphasis on cladding performance. Exams relevant to the cladding included visual and eddy current exams, profilometry, microscopy, hydrogen analysis, gallium analysis, and mechanical testing. There was no discernible effect of the type of MOX fuel on the performance of the cladding.

  12. O&M Best Practices - A Guide to Achieving Operational Efficiency (Release 2.0)

    SciTech Connect (OSTI)

    Sullivan, Gregory P.; Pugh, Ray; Melendez, Aldo P.; Hunt, W. D.

    2004-07-31

    This guide, sponsored by DOE's Federal Energy Management Program, highlights operations and maintenance (O&M) programs targeting energy efficiency that are estimated to save 5% to 20% on energy bills without a significant capital investment. The purpose of this guide is to provide the federal O&M energy manager and practitioner with useful information about O&M management, technologies, energy efficiency and cost-reduction approaches.

  13. Discovery of Pu-based superconductors and relation to other classes...

    Office of Scientific and Technical Information (OSTI)

    Discovery of Pu-based superconductors and relation to other classes of unconventional superconductors Citation Details In-Document Search Title: Discovery of Pu-based ...

  14. 239Pu Resonance Evaluation for Thermal Benchmark System Calculations

    SciTech Connect (OSTI)

    Leal, Luiz C; Noguere, G; De Saint Jean, C; Kahler, A.

    2013-01-01

    Analyses of thermal plutonium solution critical benchmark systems have indicated a deciency in the 239Pu resonance evaluation. To investigate possible solutions to this issue, the Organisation for Economic Co-operation and Development (OECD) Nuclear Energy Agency (NEA) Working Party for Evaluation Cooperation (WPEC) established Subgroup 34 to focus on the reevaluation of the 239Pu resolved resonance parameters. In addition, the impacts of the prompt neutron multiplication (nubar) and the prompt neutron ssion spectrum (PFNS) have been investigated. The objective of this paper is to present the results of the 239Pu resolved resonance evaluation eort.

  15. Elastic properties of gamma-Pu by resonant ultrasound spectroscopy

    SciTech Connect (OSTI)

    Migliori, Albert; Betts, J; Trugman, A; Mielke, C H; Mitchell, J N; Ramos, M; Stroe, I

    2009-01-01

    Despite intense experimental and theoretical work on Pu, there is still little understanding of the strange properties of this metal. We used resonant ultrasound spectroscopy method to investigate the elastic properties of pure polycrystalline Pu at high temperatures. Shear and longitudinal elastic moduli of the {gamma}-phase of Pu were determined simultaneously and the bulk modulus was computed from them. A smooth linear and large decrease of all elastic moduli with increasing temperature was observed. We calculated the Poisson ratio and found that it increases from 0.242 at 519K to 0.252 at 571K.

  16. Ferro- and antiferro-magnetism in (Np, Pu)BC

    SciTech Connect (OSTI)

    Klimczuk, T.; Kozub, A. L.; Griveau, J.-C.; Colineau, E.; Wastin, F.; Falmbigl, M.; Rogl, P.

    2015-04-01

    Two new transuranium metal boron carbides, NpBC and PuBC, have been synthesized. Rietveld refinements of powder XRD patterns of (Np,Pu)BC confirmed in both cases isotypism with the structure type of UBC. Temperature dependent magnetic susceptibility data reveal antiferromagnetic ordering for PuBC below T{sub N} = 44 K, whereas ferromagnetic ordering was found for NpBC below T{sub C} = 61 K. Heat capacity measurements prove the bulk character of the observed magnetic transition for both compounds. The total energy electronic band structure calculations support formation of the ferromagnetic ground state for NpBC and the antiferromagnetic ground state for PuBC.

  17. Probing Actinide Electronic Structure through Pu Cluster Calculations

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

    Ryzhkov, Mickhail V.; Mirmelstein, Alexei; Yu, Sung-Woo; Chung, Brandon W.; Tobin, James G.

    2013-02-26

    The calculations for the electronic structure of clusters of plutonium have been performed, within the framework of the relativistic discrete-variational method. Moreover, these theoretical results and those calculated earlier for related systems have been compared to spectroscopic data produced in the experimental investigations of bulk systems, including photoelectron spectroscopy. Observation of the changes in the Pu electronic structure as a function of size provides powerful insight for aspects of bulk Pu electronic structure.

  18. Elasticity of Pu -a window into fundamental understanding and aging

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Elasticity of Pu -a window into fundamental understanding and aging Citation Details In-Document Search Title: Elasticity of Pu -a window into fundamental understanding and aging No abstract prepared. Authors: Migliori, Albert [1] ; Saleh, Tarik A. [1] ; Freibert, Franz J. [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2012-06-06 OSTI Identifier: 1043024 Report Number(s): LA-UR-12-21957 TRN: US201213%%51 DOE Contract Number:

  19. Report on the Feasibility of Pu Photoelectron Spectroscopy with Microscopic

    Office of Scientific and Technical Information (OSTI)

    and Nanoscopic Samples at NSLSII (Technical Report) | SciTech Connect Report on the Feasibility of Pu Photoelectron Spectroscopy with Microscopic and Nanoscopic Samples at NSLSII Citation Details In-Document Search Title: Report on the Feasibility of Pu Photoelectron Spectroscopy with Microscopic and Nanoscopic Samples at NSLSII Authors: Tobin, J G Publication Date: 2012-09-11 OSTI Identifier: 1053685 Report Number(s): LLNL-TR-582213 DOE Contract Number: W-7405-ENG-48 Resource Type:

  20. Status of Pu-239 Evaluations (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Status of Pu-239 Evaluations Citation Details In-Document Search Title: Status of Pu-239 Evaluations Authors: Kawano, Toshihiko [1] ; Talou, Patrick [1] ; Chadwick, Mark B. [1] + Show Author Affiliations Los Alamos National Laboratory [Los Alamos National Laboratory Publication Date: 2013-12-06 OSTI Identifier: 1110310 Report Number(s): LA-UR-13-29265 DOE Contract Number: AC52-06NA25396 Resource Type: Conference Resource Relation: Conference: NEMEA-7/CIELO, International Collaboration on Nuclear

  1. The Evolution in Pu Nanocluster Electronic Structure: from Atomicity to

    Office of Scientific and Technical Information (OSTI)

    Three Dimensionality (Conference) | SciTech Connect Conference: The Evolution in Pu Nanocluster Electronic Structure: from Atomicity to Three Dimensionality Citation Details In-Document Search Title: The Evolution in Pu Nanocluster Electronic Structure: from Atomicity to Three Dimensionality Authors: Tobin, J G ; Yu, S W ; Chung, B W ; Ryzhkov, M V ; Mirmelstein, A V Publication Date: 2013-07-18 OSTI Identifier: 1149047 Report Number(s): LLNL-CONF-642076 DOE Contract Number:

  2. The Evolution in Pu Nanocluster Electronic Structure: from Atomicity to

    Office of Scientific and Technical Information (OSTI)

    Three Dimensionality (Conference) | SciTech Connect Conference: The Evolution in Pu Nanocluster Electronic Structure: from Atomicity to Three Dimensionality Citation Details In-Document Search Title: The Evolution in Pu Nanocluster Electronic Structure: from Atomicity to Three Dimensionality × 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 Technical Information (OSTI) and is provided as a public

  3. A Best Practice for Developing Availability Guarantee Language in Photovoltaic (PV) O&M Agreements.

    SciTech Connect (OSTI)

    Klise, Geoffrey Taylor; Balfour, John

    2015-11-01

    This document outlines the foundation for developing language that can be utilized in an Equipment Availability Guarantee, typically included in an O&M services agreement between a PV system or plant owner and an O&M services provider, or operator. Many of the current PV O&M service agreement Availability Guarantees are based on contracts used for traditional power generation, which create challenges for owners and operators due to the variable nature of grid-tied photovoltaic generating technologies. This report documents language used in early PV availability guarantees and presents best practices and equations that can be used to more openly communicate how the reliability of the PV system and plant equipment can be expressed in an availability guarantee. This work will improve the bankability of PV systems by providing greater transparency into the equipment reliability state to all parties involved in an O&M services contract.

  4. Where might I find simplified Data on Capital, O&M, and fuel...

    Open Energy Info (EERE)

    Where might I find simplified Data on Capital, O&M, and fuel costs? Home I teach math to high school seniors. My students are studying energy in all their classes. I have just...

  5. Average Structure Evolution of ?-phase Pu-Ga Alloys

    SciTech Connect (OSTI)

    Smith, Alice Iulia; Page, Katharine L.; Gourdon, Olivier; Siewenie, Joan E.; Richmond, Scott; Saleh, Tarik A.; Ramos, Michael; Schwartz, Daniel S.

    2015-03-30

    [Full Text] Plutonium metal is a highly unusual element, exhibiting six allotropes at ambient pressure, from room temperature to its melting point. Many phases of plutonium metal are unstable with temperature, pressure, chemical additions, and time. This strongly affects structure and properties, and becomes of high importance, particularly when considering effects on structural integrity over long time periods. The fcc ?-phase deserves additional attention, not only in the context of understanding the electronic structure of Pu, but also as one of the few high-symmetry actinide phases that can be stabilized down to ambient pressure and room temperature by alloying it with trivalent elements. We will present results on recent work on aging of Pu-2at.%Ga and Pu-7at.%Ga alloys

  6. DEVELOPMENT PROGRAM FOR PU-238 AQUEOUS RECOVERY PROCESS

    SciTech Connect (OSTI)

    M. PANSOY-HJELVIK; M. REIMUS; ET AL

    2000-10-01

    Aqueous processing is necessary for the removal of impurities from {sup 238}Pu dioxide ({sup 238}PuO{sub 2}) fuel due to unacceptable levels of {sup 234}U and other non-actinide impurities in the scrap fuel. Impurities at levels above General Purpose Heat Source (GPHS) fuel specifications may impair the performance.of the heat sources. Efforts at Los Alamos have focused on developing the bench scale methodology for the aqueous process steps which includes comminution, dissolution, ion exchange, precipitation, and calcination. Recently, work has been performed to qualify the bench scale methodology, to show that the developed process produces pure {sup 238}PuO{sub 2} meeting GPHS fuel specifications. In addition, this work has enabled us to determine how waste volumes may be minimized during full-scale processing. Results of process qualification for the bench scale aqueous recovery operation and waste minimization efforts are presented.

  7. Transuranic concentrations in reef and pelagic fish from the Marshall Islands. [/sup 239/Pu, /sup 240/Pu

    SciTech Connect (OSTI)

    Noshkin, V.E.; Eagle, R.J.; Wong, K.M.; Jokela, T.A.

    1980-09-01

    Concentrations of /sup 239 + 240/Pu are reported in tissues of several species of reef and pelagic fish caught at 14 different atolls in the northern Marshall Islands. Several regularities that are species dependent are evident in the distribution of /sup 239 + 240/Pu among different body tissues. Concentrations in liver always exceeded those in bone and concentrations were lowest in the muscle of all fish analyzed. A progressive discrimination against /sup 239 + 240/Pu was observed at successive trophic levels at all atolls except Bikini and Enewetak, where it was difficult to conclude if any real difference exists between the average concentration factor for /sup 239 + 240/Pu among all fish, which include bottom feeding and grazing herbivores, bottom feeding carnivores, and pelagic carnivores from different atoll locations. The average concentration of /sup 239 + 240/Pu in the muscle of surgeonfish from Bikini and Enewetak was not significantly different from the average concentrations determined in these fish at the other, lesser contaminated atolls. Concentrations among all 3rd, 4th, and 5th trophic level species are highest at Bikini where higher environmental concentrations are found. The reasons for the anomalously low concentrations in herbivores from Bikini and Enewetak are not known.

  8. Detection and Quantification of Pu(III, IV, V, and VI) Using...

    Office of Scientific and Technical Information (OSTI)

    of Pu(III, IV, V, and VI) Using a1.0-meter Liquid Core Waveguide Citation Details In-Document Search Title: Detection and Quantification of Pu(III, IV, V, and VI) Using ...

  9. First-principles study of the Kondo physics of a single Pu impurity...

    Office of Scientific and Technical Information (OSTI)

    First-principles study of the Kondo physics of a single Pu impurity in a Th host Citation ... Title: First-principles study of the Kondo physics of a single Pu impurity in a Th host ...

  10. Energy Dependence of Fission Product Yields for 239Pu, 235U,...

    Office of Scientific and Technical Information (OSTI)

    Energy Dependence of Fission Product Yields for 239Pu, 235U, and 238U Citation Details In-Document Search Title: Energy Dependence of Fission Product Yields for 239Pu, 235U, and...

  11. Summary of Pu u O o - Kupaianaha Eruption, Kilauea Volcano, Hawaii...

    Open Energy Info (EERE)

    Pu u O o - Kupaianaha Eruption, Kilauea Volcano, Hawaii Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Summary of Pu u O o - Kupaianaha Eruption,...

  12. Atomic Structure and Phase Transformations in Pu Alloys

    SciTech Connect (OSTI)

    Schwartz, A J; Cynn, H; Blobaum, K M; Wall, M A; Moore, K T; Evans, W J; Farber, D L; Jeffries, J R; Massalski, T B

    2008-04-28

    Plutonium and plutonium-based alloys containing Al or Ga exhibit numerous phases with crystal structures ranging from simple monoclinic to face-centered cubic. Only recently, however, has there been increased convergence in the actinides community on the details of the equilibrium form of the phase diagrams. Practically speaking, while the phase diagrams that represent the stability of the fcc {delta}-phase field at room temperature are generally applicable, it is also recognized that Pu and its alloys are never truly in thermodynamic equilibrium because of self-irradiation effects, primarily from the alpha decay of Pu isotopes. This article covers past and current research on several properties of Pu and Pu-(Al or Ga) alloys and their connections to the crystal structure and the microstructure. We review the consequences of radioactive decay, the recent advances in understanding the electronic structure, the current research on phase transformations and their relations to phase diagrams and phase stability, the nature of the isothermal martensitic {delta} {yields} {alpha}{prime} transformation, and the pressure-induced transformations in the {delta}-phase alloys. New data are also presented on the structures and phase transformations observed in these materials following the application of pressure, including the formation of transition phases.

  13. Characterization of Pu-238 Heat Source Granule Containment

    SciTech Connect (OSTI)

    Richardson, Paul Dean II; Sanchez, Joey Leo; Wall, Angelique Dinorah; Chavarria, Rene

    2015-02-11

    The Milliwatt Radioisotopic Themoelectric Generator (RTG) provides power for permissive-action links. Essentially these are nuclear batteries that convert thermal energy to electrical energy using a doped silicon-germanium thermopile. The thermal energy is provided by a heat source made of 238Pu, in the form of 238PuO2 granules. The granules are contained by 3 layers of encapsulation. A thin T-111 liner surrounds the 238PuO2 granules and protects the second layer (strength member) from exposure to the fuel granules. An outer layer of Hastalloy-C protects the T-111 from oxygen embrittlement. The T-111 strength member is considered the critical component in this 238PuO2 containment system. Any compromise in the strength member seen during destructive testing required by the RTG surveillance program is characterized. The T-111 strength member is characterized through Scanning Electron Microscopy (SEM), and Metallography. SEM is used in the Secondary Electron mode to reveal possible grain boundary deformation and/or cracking in the region of the strength member weld. Deformation and cracking uncovered by SEM are further characterized by Metallography. Metallography sections are mounted and polished, observed using optical microscopy, then documented in the form of microphotographs. SEM mat further be used to examine polished Metallography mounts to characterize elements using the SEM mode of Energy Dispersive X-ray spectroscopy (EDS).

  14. Selection and Evaluation of a new Pu Density Measurement Fluid

    SciTech Connect (OSTI)

    Dziewinska, Krystyna; Peters, Michael A; Martinez, Patrick P; Dziewinski, Jacek J; Pugmire, David L; Trujillo, Stephen M; La Verne, Jake A; Rajesh, P

    2009-01-01

    This paper summarizes efforts leading to selection of a new fluid for the determination of the density of large Pu parts. Based on an extended literature search, perfluorotributylamine (FC-43) was chosen for an experimental study. Plutonium coupon corrosion studies were performed by exposing Pu to deaerated and aerated solutions and measuring corrosion gravimetrically. Corrosion rates were determined. Samples of deaerated and aerated perfuluorotributylamine (FC-43) were also irradiated with {sup 60}Co gamma rays (96 Gy/min) to various doses. The samples were extracted with NaOH and analyzed by IC and showed the presence of F and Cl{sup -}. The G-values were established. In surface study experiments Pu coupons were exposed to deaerated and aerated solutions of FC-43 and analyzed by X-ray photoelectron spectroscopy (XPS). The XPS data indicate that there is no detectable surface effect caused by the new fluid. In conclusion the FC-43 was determined to be a very effective and practical fluid for Pu density measurements.

  15. Significant issues and changes for ANSI/ASME OM-1 1981, part 1, ASME OMc code-1994, and ASME OM Code-1995, Appendix I, inservice testing of pressure relief devices in light water reactor power plants

    SciTech Connect (OSTI)

    Seniuk, P.J.

    1996-12-01

    This paper identifies significant changes to the ANSI/ASME OM-1 1981, Part 1, and ASME Omc Code-1994 and ASME OM Code-1995, Appendix I, {open_quotes}Inservice Testing of Pressure Relief Devices in Light-Water Reactor Power Plants{close_quotes}. The paper describes changes to different Code editions and presents insights into the direction of the code committee and selected topics to be considered by the ASME O&M Working Group on pressure relief devices. These topics include scope issues, thermal relief valve issues, as-found and as-left set-pressure determinations, exclusions from testing, and cold setpoint bench testing. The purpose of this paper is to describe some significant issues being addressed by the O&M Working Group on Pressure Relief Devices (OM-1). The writer is currently the chair of OM-1 and the statements expressed herein represents his personal opinion.

  16. Type B Accident Investigation on the August 5, 2003, Pu-238 Multiple Uptake

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

    Event at the Pu Facility, Los Alamos National Laboratory | Department of Energy on the August 5, 2003, Pu-238 Multiple Uptake Event at the Pu Facility, Los Alamos National Laboratory Type B Accident Investigation on the August 5, 2003, Pu-238 Multiple Uptake Event at the Pu Facility, Los Alamos National Laboratory December 1, 2003 On August 5, 2003, a release of plutonium-238 occurred in a storage room at the Plutonium Facility, Los Alamos National Laboratory, resulting in radiation doses to

  17. Characterization of Pu-238 heat source granule containment

    SciTech Connect (OSTI)

    Richardson Ii, P D; Thronas, D L; Romero, J P; Sandoval, F E; Neuman, A D; Duncan, W S

    2008-01-01

    The Milliwatt Radioisotopic Thermoelectric Generator (RTG) provides power for permissive-action links. These nuclear batteries convert thermal energy to electrical energy using a doped silicon-germanium thermopile. The thermal energy is provided by a heat source made of {sup 238}Pu, in the form of {sup 238}PuO{sub 2} granules. The granules are contained in 3 layers of encapsulation. A thin T-111 liner surrounds the {sup 238}PuO{sub 2} granules and protects the second layer (strength member) from exposure to the fuel granules. The T-111 strength member contains the fuel under impact condition. An outer clad of Hastelloy-C protects the T-111 from oxygen embrittlement. The T-111 strength member is considered the critical component in this {sup 238}PuO{sub 2} containment system. Any compromise in the strength member is something that needs to be characterized. Consequently, the T-111 strength member is characterized upon it's decommissioning through Scanning Electron Microscopy (SEM), and Metallography. SEM is used in Secondary Electron mode to reveal possible grain boundary deformation and/or cracking in the region of the strength member weld. Deformation and cracking uncovered by SEM are further characterized by Metallography. Metallography sections are mounted and polished, observed using optical microscopy, then documented in the form of photomicrographs. SEM may further be used to examine polished Metallography mounts to characterize elements using the SEM mode of Energy Dispersive X-ray Spectroscopy (EDS). This paper describes the characterization of the metallurgical condition of decommissioned RTG heat sources.

  18. Slow Neutron Velocity Spectrometer Transmission Studies Of Pu

    DOE R&D Accomplishments [OSTI]

    Havens, W. W. Jr.; Melkonian, E.; Rainwater, L. J.; Levin, M.

    1951-05-28

    The slow neutron transmission of several samples of Pu has been investigated with the Columbia Neutron Velocity Spectrometer. Data are presented in two groups, those covering the energy region from 0 to 6 ev, and those covering the region above 6 ev. Below 6 ev the resolution was relatively good, and a detailed study of the cross section variation was made. Work above 6 ev consisted of merely locating levels and obtaining a rough idea of their strengths.

  19. AFS-2 FLOWSHEET MODIFICATIONS TO ADDRESS THE INGROWTH OF PU(VI) DURING METAL DISSOLUTION

    SciTech Connect (OSTI)

    Crapse, K.; Rudisill, T.; O'Rourke, P.; Kyser, E.

    2014-07-02

    In support of the Alternate Feed Stock Two (AFS-2) PuO{sub 2} production campaign, Savannah River National Laboratory (SRNL) conducted a series of experiments concluding that dissolving Pu metal at 95C using a 610 M HNO{sub 3} solution containing 0.050.2 M KF and 02 g/L B could reduce the oxidation of Pu(IV) to Pu(VI) as compared to dissolving Pu metal under the same conditions but at or near the boiling temperature. This flowsheet was demonstrated by conducting Pu metal dissolutions at 95C to ensure that PuO{sub 2} solids were not formed during the dissolution. These dissolution parameters can be used for dissolving both Aqueous Polishing (AP) and MOX Process (MP) specification materials. Preceding the studies reported herein, two batches of Pu metal were dissolved in the H-Canyon 6.1D dissolver to prepare feed solution for the AFS-2 PuO{sub 2} production campaign. While in storage, UV-visible spectra obtained from an at-line spectrophotometer indicated the presence of Pu(VI). Analysis of the solutions also showed the presence of Fe, Ni, and Cr. Oxidation of Pu(IV) produced during metal dissolution to Pu(VI) is a concern for anion exchange purification. Anion exchange requires Pu in the +4 oxidation state for formation of the anionic plutonium(IV) hexanitrato complex which absorbs onto the resin. The presence of Pu(VI) in the anion feed solution would require a valence adjustment step to prevent losses. In addition, the presence of Cr(VI) would result in absorption of chromate ion onto the resin and could limit the purification of Pu from Cr which may challenge the purity specification of the final PuO{sub 2} product. Initial experiments were performed to quantify the rate of oxidation of Pu(IV) to Pu(VI) (presumed to be facilitated by Cr(VI)) as functions of the HNO{sub 3} concentration and temperature in simulated dissolution solutions containing Cr, Fe, and Ni. In these simulated Pu dissolutions studies, lowering the temperature from near boiling to 95 C reduced the oxidation rate of Pu(IV) to Pu(VI). For 8.1 M HNO{sub 3} simulated dissolution solutions, at near boiling conditions >35% Pu(VI) was present in 50 h while at 95 C <10% Pu(VI) was present at 50 h. At near boiling temperatures, eliminating the presence of Cr and varying the HNO{sub 3} concentration in the range of 78.5 M had little effect on the rate of conversion of Pu(IV) to Pu(VI). HNO{sub 3} oxidation of Pu(IV) to Pu(VI) in a pure solution has been reported previously. Based on simulated dissolution experiments, this study concluded that dissolving Pu metal at 95C using a 6 to 10 M HNO{sub 3} solution 0.050.2 M KF and 02 g/L B could reduce the rate of oxidation of Pu(IV) to Pu(VI) as compared to near boiling conditions. To demonstrate this flowsheet, two small-scale experiments were performed dissolving Pu metal up to 6.75 g/L. No Pu-containing residues were observed in the solutions after cooling. Using Pu metal dissolution rates measured during the experiments and a correlation developed by Holcomb, the time required to completely dissolve a batch of Pu metal in an H-Canyon dissolver using this flowsheet was estimated to require nearly 5 days (120 h). This value is reasonably consistent with an estimate based on the Batch 2 and 3 dissolution times in the 6.1D dissolver and Pu metal dissolution rates measured in this study and by Rudisill et al. Data from the present and previous studies show that the Pu metal dissolution rate decreases by a factor of approximately two when the temperature decreased from boiling (112 to 116C) to 95C. Therefore, the time required to dissolve a batch of Pu metal in an H-Canyon dissolver at 95C would likely double (from 36 to 54 h) and require 72 to 108 h depending on the surface area of the Pu metal. Based on the experimental studies, a Pu metal dissolution flowsheet utilizing 610 M HNO{sub 3} containing 0.050.2 M KF (with 02 g/L B) at 95C is recommended to reduce the oxidation of Pu(IV) to Pu(VI) as compared to near boiling conditions. The time required to completely di

  20. Neutron Resonance Parameters and Covariance Matrix of 239Pu

    SciTech Connect (OSTI)

    Derrien, Herve; Leal, Luiz C; Larson, Nancy M

    2008-08-01

    In order to obtain the resonance parameters in a single energy range and the corresponding covariance matrix, a reevaluation of 239Pu was performed with the code SAMMY. The most recent experimental data were analyzed or reanalyzed in the energy range thermal to 2.5 keV. The normalization of the fission cross section data was reconsidered by taking into account the most recent measurements of Weston et al. and Wagemans et al. A full resonance parameter covariance matrix was generated. The method used to obtain realistic uncertainties on the average cross section calculated by SAMMY or other processing codes was examined.

  1. Savannah River Site: Plutonium Preparation Project (PuPP) at Savannah River

    Energy Savers [EERE]

    Site | Department of Energy Site: Plutonium Preparation Project (PuPP) at Savannah River Site Savannah River Site: Plutonium Preparation Project (PuPP) at Savannah River Site Full Document and Summary Versions are available for download PDF icon Savannah River Site: Plutonium Preparation Project (PuPP) at Savannah River Site PDF icon Summary - Plutonium Preparation Project at the Savannah River Site More Documents & Publications EIS-0283-S2: Interim Action Determination EIS-0283-S2:

  2. TE Connectivity Finds Answers in Tomography

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

    TE Connectivity Finds Answers in Tomography TE Connectivity Finds Answers in Tomography Print Thursday, 22 August 2013 10:50 TE Connectivity is a world leader in connectivity-the...

  3. Neutron capture of /sup 122/Te, /sup 123/Te, /sup 124/Te, /sup 125/Te, and /sup 126/Te

    SciTech Connect (OSTI)

    Macklin, R.L.; Winters, R.R.

    1989-07-01

    Isotopically enriched samples of the tellurium isotopes from mass 122 to mass 126 were used to measure neutron capture in the energy range 2.6 keV to 600 keV at the Oak Ridge Electron Linear Accelerator pulsed neutron source. Starting at 2.6 keV, over 200 Breit-Wigner resonances for each isotope were used to describe the capture data. Least-squares adjustment gave parameters and their uncertainties for a total of 1659 resonances. Capture cross sections averaged over Maxwellian neutron distributions with temperatures ranging from kT = 5 keV to kT = 100 keV were derived for comparison with stellar nucleosynthesis calculations. For the three isotopes shielded from the astrophysical r-process, /sup 122/Te, /sup 123/Te and /sup 124/Te at kT = 30 keV the respective values were (280 /plus minus/ 10) mb, (819 /plus minus/ 30) mb and (154 /plus minus/ 6) mb. The corresponding products of cross section and solar system abundance are nearly equal in close agreement with s-process nucleosynthesis calculations. 26 refs., 8 figs., 10 tabs.

  4. Overview of advanced technologies for stabilization of {sup 238}Pu-contaminated waste

    SciTech Connect (OSTI)

    Ramsey, K.B.; Foltyn, E.M.; Heslop, J.M.

    1998-02-01

    This paper presents an overview of potential technologies for stabilization of {sup 238}Pu-contaminated waste. Los Alamos National Laboratory (LANL) has processed {sup 238}PuO{sub 2} fuel into heat sources for space and terrestrial uses for the past several decades. The 88-year half-life of {sup 238}Pu and thermal power of approximately 0.6 watts/gram make this isotope ideal for missions requiring many years of dependable service in inaccessible locations. However, the same characteristic which makes {sup 238}Pu attractive for heat source applications, the high Curie content (17 Ci/gram versus 0.06 Ci/gram for 239{sup Pu}), makes disposal of {sup 238}Pu-contaminated waste difficult. Specifically, the thermal load limit on drums destined for transport to the Waste Isolation Pilot Plant (WIPP), 0.23 gram per drum for combustible waste, is impossible to meet for nearly all {sup 238}Pu-contaminated glovebox waste. Use of advanced waste treatment technologies including Molten Salt Oxidation (MSO) and aqueous chemical separation will eliminate the combustible matrix from {sup 238}Pu-contaminated waste and recover kilogram quantities of {sup 238}PuO{sub 2} from the waste stream. A conceptual design of these advanced waste treatment technologies will be presented.

  5. Thermal Analysis of ZPPR High Pu Content Stored Fuel

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

    Solbrig, Charles W.; Pope, Chad L.; Andrus, Jason P.

    2014-01-01

    The Zero Power Physics Reactor (ZPPR) operated from April 18, 1969, until 1990. ZPPR operated at low power for testing nuclear reactor designs. This paper examines the temperature of Pu content ZPPR fuel while it is in storage. Heat is generated in the fuel due to Pu and Am decay and is a concern for possible cladding damage. Damage to the cladding could lead to fuel hydriding and oxidizing. A series of computer simulations were made to determine the range of temperatures potentially occuring in the ZPPR fuel. The maximum calculated fuel temperature is 292°C (558°F). Conservative assumptions in themore » model intentionally overestimate temperatures. The stored fuel temperatures are dependent on the distribution of fuel in the surrounding storage compartments, the heat generation rate of the fuel, and the orientation of fuel. Direct fuel temperatures could not be measured but storage bin doors, storage sleeve doors, and storage canister temperatures were measured. Comparison of these three temperatures to the calculations indicates that the temperatures calculated with conservative assumptions are, as expected, higher than the actual temperatures. The maximum calculated fuel temperature with the most conservative assumptions is significantly below the fuel failure criterion of 600°C (1,112°F).« less

  6. Top Operations and Maintenance (O&M) Efficiency Opportunities at DoD/Army Sites - A Guide for O&M/Energy Managers and Practitioners

    SciTech Connect (OSTI)

    Sullivan, Gregory P.; Dean, Jesse D.; Dixon, Douglas R.

    2007-05-25

    This report, sponsored the Army's Energy Engineering Analysis Program, provides the Operations and Maintenance (O&M) Energy manager and practitioner with useful information about the top O&M opportunities consistently found across the DoD/Army sector. The target is to help the DoD/Army sector develop a well-structured and organized O&M program.

  7. Gamma-ray Output Spectra from 239 Pu Fission

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

    Ullmann, John

    2015-05-25

    Gamma-ray multiplicities, individual gamma-ray energy spectra, and total gamma energy spectra following neutron-induced fission of 239Pu were measured using the DANCE detector at Los Alamos. Corrections for detector response were made using a forward-modeling technique based on propagating sets of gamma rays generated from a paramaterized model through a GEANT model of the DANCE array and adjusting the parameters for best fit to the measured spectra. The results for the gamma-ray spectrum and multiplicity are in general agreement with previous results, but the measured total gamma-ray energy is about 10% higher. A dependence of the gamma-ray spectrum on the gamma-raymore » multplicity was also observed. Global model calculations of the multiplicity and gamma energy distributions are in good agreement with the data, but predict a slightly softer total-energy distribution.« less

  8. Determining site-specific drum loading criteria for storing combustible {sup 238}Pu waste

    SciTech Connect (OSTI)

    Marshall, R.S.; Callis, E.L.; Cappis, J.H.; Espinoza, J.M.; Foltyn, E.M.; Reich, B.T.; Smith, M.C.

    1994-02-01

    Waste containing hydrogenous-combustible material contaminated with {sup 238}Pu can generate hydrogen gas at appreciable rates through alpha radiolysis. To ensure safe transportation of WIPP drums, the limit for {sup 238}Pu-combustible waste published in the WIPP TRUPACT-11 CONTENT (TRUCON) CODES is 21 milliwafts per 55 gallon drum. This corresponds to about 45 milligrams of {sup 238}PuO{sub 2} used for satellite heat source-electrical generators. The Los Alamos waste storage site adopted a {sup 238}Pu waste storage criteria based on these TRCUCON codes. However, reviews of the content in drums of combustible waste generated during heat source assembly at Los Alamos showed the amount of {sup 238}Pu is typically much greater than 45 milligrams. It is not feasible to appreciably reduce Los Alamos {sup 238}Pu waste drum loadings without significantly increasing waste volumes or introducing unsafe practices. To address this concern, a series of studies were implemented to evaluate the applicability of the TRUCON limits for storage of this specific waste. Addressed in these evaluations were determination of the hydrogen generation rate, hydrogen diffusion rates through confinement layers and vent filters, and packaging requirements specific to Los Alamos generated {sup 238}Pu contaminated combustible waste. These studies also showed that the multiple-layer packaging practices in use at Los Alamos could be relaxed without significantly increasing the risk of contamination. Based on a model developed to predict H{sub 2} concentrations in packages and drum headspace, the site specific effective hydrogen generation rate, and hydrogen-diffusion values, and revising the waste packaging practices, we were able to raise the safe loading limit for {sup 238}Pu waste drums for on site storage to the gram levels typical of currently generated {sup 238}Pu waste.

  9. Code cases for implementing risk-based inservice testing in the ASME OM code

    SciTech Connect (OSTI)

    Rowley, C.W.

    1996-12-01

    Historically inservice testing has been reasonably effective, but quite costly. Recent applications of plant PRAs to the scope of the IST program have demonstrated that of the 30 pumps and 500 valves in the typical plant IST program, less than half of the pumps and ten percent of the valves are risk significant. The way the ASME plans to tackle this overly-conservative scope for IST components is to use the PRA and plant expert panels to create a two tier IST component categorization scheme. The PRA provides the quantitative risk information and the plant expert panel blends the quantitative and deterministic information to place the IST component into one of two categories: More Safety Significant Component (MSSC) or Less Safety Significant Component (LSSC). With all the pumps and valves in the IST program placed in MSSC or LSSC categories, two different testing strategies will be applied. The testing strategies will be unique for the type of component, such as centrifugal pump, positive displacement pump, MOV, AOV, SOV, SRV, PORV, HOV, CV, and MV. A series of OM Code Cases are being developed to capture this process for a plant to use. One Code Case will be for Component Importance Ranking. The remaining Code Cases will develop the MSSC and LSSC testing strategy for type of component. These Code Cases are planned for publication in early 1997. Later, after some industry application of the Code Cases, the alternative Code Case requirements will gravitate to the ASME OM Code as appendices.

  10. Microscopic Calculation of 240Pu Scission with a Finite-Range Effective

    Office of Scientific and Technical Information (OSTI)

    Force (Journal Article) | SciTech Connect Journal Article: Microscopic Calculation of 240Pu Scission with a Finite-Range Effective Force Citation Details In-Document Search Title: Microscopic Calculation of 240Pu Scission with a Finite-Range Effective Force Hartree-Fock-Bogoliubov calculations of hot fission in {sup 240}Pu have been performed with a newly-implemented code that uses the D1S finite-range effective interaction. The hot-scission line is identified in the

  11. Microscopic Calculation of Fission Fragment Energies for the 239Pu(nth,f)

    Office of Scientific and Technical Information (OSTI)

    Reaction (Technical Report) | SciTech Connect Microscopic Calculation of Fission Fragment Energies for the 239Pu(nth,f) Reaction Citation Details In-Document Search Title: Microscopic Calculation of Fission Fragment Energies for the 239Pu(nth,f) Reaction We calculate the total kinetic and excitation energies of fragments produced in the thermal-induced fission of {sup 239}Pu. This result is a proof-of-principle demonstration for a microscopic approach to the calculation of fission-fragment

  12. Multiscale Speciation of U and Pu at Chernobyl, Hanford, Los Alamos,

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

    McGuire AFB, Mayak, and Rocky Flats | Stanford Synchrotron Radiation Lightsource Multiscale Speciation of U and Pu at Chernobyl, Hanford, Los Alamos, McGuire AFB, Mayak, and Rocky Flats Friday, June 26, 2015 X-ray fluorescence maps of (clockwise from upper right) Ga, U, Ca, Pu, Ti, and K in a 350 micron PuO2-UO2 composite particle produced by the fire that consumed a nuclear armed BOMARC missile at McGuire AFB in 1960, measured with the two micron focused x-ray beam at SSRL. EST June 2,

  13. ZPR-6 assembly 7 high {sup 240} PU core : a cylindrical assemby with mixed (PU, U)-oxide fuel and a central high {sup 240} PU zone.

    SciTech Connect (OSTI)

    Lell, R. M.; Schaefer, R. W.; McKnight, R. D.; Tsiboulia, A.; Rozhikhin, Y.; Nuclear Engineering Division; Inst. of Physics and Power Engineering

    2007-10-01

    Over a period of 30 years more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited to form the basis for criticality safety benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. The term 'benchmark' in a ZPR program connotes a particularly simple loading aimed at gaining basic reactor physics insight, as opposed to studying a reactor design. In fact, the ZPR-6/7 Benchmark Assembly (Reference 1) had a very simple core unit cell assembled from plates of depleted uranium, sodium, iron oxide, U3O8, and plutonium. The ZPR-6/7 core cell-average composition is typical of the interior region of liquid-metal fast breeder reactors (LMFBRs) of the era. It was one part of the Demonstration Reactor Benchmark Program,a which provided integral experiments characterizing the important features of demonstration-size LMFBRs. As a benchmark, ZPR-6/7 was devoid of many 'real' reactor features, such as simulated control rods and multiple enrichment zones, in its reference form. Those kinds of features were investigated experimentally in variants of the reference ZPR-6/7 or in other critical assemblies in the Demonstration Reactor Benchmark Program.

  14. RAPID DETERMINATION OF 237 NP AND PU ISOTOPES IN WATER BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY

    SciTech Connect (OSTI)

    Maxwell, S.; Jones, V.; Culligan, B.; Nichols, S.; Noyes, G.

    2010-06-23

    A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of {sup 237}Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry; a hybrid approach. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and alpha spectrometry so that long and short-lived Pu isotopes can be measured successfully. The method allows for simultaneous extraction of 20 samples (including QC samples) in 4 to 6 hours, and can also be used for emergency response. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu, {sup 238}Pu, and {sup 239}Pu were measured by alpha spectrometry.

  15. Detection and Quantification of Pu(III, IV, V, and VI) Using...

    Office of Scientific and Technical Information (OSTI)

    Detection and quantification of the aquo ions of Pu in 1 MHClO4 was carried out using a 1-meter liquid core waveguide (LCW) coupledto a fiber optic UV-Vis spectrometer. Detection ...

  16. Thermophysical properties of ??Pu{sub 2}O{sub 3}: A new potential model

    SciTech Connect (OSTI)

    Gnay, S. D. Akdere, .; Ta?seven, .; Akgen, B.

    2013-12-16

    ??Pu{sub 2}O{sub 3} is an important material among plutonium based materials in nuclear industry. Pure plutonium surfaces quickly oxidizes into ??Pu{sub 2}O{sub 3} and PuO{sub 2} which are in the form of layers one on another. Here we have investigated thermal properties of ??Pu{sub 2}O{sub 3} by molecular dynamics simulation by using a partially ionic semi-empirical rigid ion potential. Mechanical properties, thermal expansion, and heat capacity are calculated. Results were compared with available experimental data and quantum calculation [2]. Due to the experimental limitations such as toxicity and radiation effects, studying the physical properties of such materials from molecular dynamics simulations have vital importance.

  17. Characterization of high-fired PuO/sub 2/ as a certified reference material

    SciTech Connect (OSTI)

    Legeled, M.A.; Cacic, C.G.; Crawford, D.W.; Spaletto, M.I.

    1984-07-01

    The New Brunswick Laboratory (NBL), U.S. Department of Energy, has certified a plutonium dioxide reference material, CRM 122, for plutonium assay and isotopic composition. The PuO/sub 2/ standard, one of several certified Pu reference materials currently being developed at NBL for use in instrumentation calibration and measurement control for safeguards, establishes traceability to the national measurement base. This plutonium reference material in the oxide form provides more directly demonstrable traceability than metal because it undergoes the same chemical treatment for dissolution as PuO/sub 2/ fuel materials. Various tests for achieving a constant weight and for dissolving CRM 122 high-fired PuO/sub 2/ were conducted. Results of these tests as well as the certification data generated by controlled-potential coulometry for plutonium assay and by thermal ionization mass spectrometry for isotopic composition will also be presented and discussed.

  18. Mass transport properties of Pu/DT mixtures from orbital free molecular dynamics simulations

    SciTech Connect (OSTI)

    Kress, Joel David; Ticknor, Christopher; Collins, Lee A.

    2015-09-16

    Mass transport properties (shear viscosity and diffusion coefficients) for Pu/DT mixtures were calculated with Orbital Free Molecular Dynamics (OFMD). The results were fitted to simple functions of mass density (for ρ=10.4 to 62.4 g/cm3) and temperature (for T=100 up to 3,000 eV) for Pu/DT mixtures consisting of 100/0, 25/75, 50/50, and 75/25 by number.

  19. COMPUTER SIMULATIONS TO ADDRESS PU-FE EUTECTICISSUE IN 3013 STORAGE VESSEL

    SciTech Connect (OSTI)

    Gupta, N; Allen Smith, A

    2007-03-06

    On November 22, 2005, the Manager of the Plutonium Finishing Plant (PFP) in Richland, WA issued an Occurrence Report involving a potential Pu-Fe eutectic failure mechanism for the stainless steel (SS) 3013 cans containing plutonium (Pu) metal. Four additional reports addressed nuclear safety concerns about the integrity of stainless steel containers holding plutonium during fire scenarios. The reports expressed a belief that the probability and consequences of container failure due to the formation of a plutonium-iron eutectic alloy had been overlooked. Simplified thermal model to address the Pu-Fe eutectic concerns using axisymmetric model similar to the models used in the 9975 SARP were performed. The model uses Rocky Flats configuration with 2 stacked Pu buttons inside a 3013 assembly. The assembly has an outer can, an inner can, and a convenience can, all stainless steel. The boundary conditions are similar to the regulatory 30 minutes HAC fire analyses. Computer simulations of the HAC fire transients lasting 4 hours of burn time show that the interface between the primary containment vessel and the Pu metal in the 9975 package will not reach Pu-Fe eutectic temperature of 400 C.

  20. TE Connectivity Finds Answers in Tomography

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

    TE Connectivity Finds Answers in Tomography TE Connectivity Finds Answers in Tomography Print Thursday, 22 August 2013 10:50 TE Connectivity is a world leader in connectivity-the $13 billion global company designs and manufactures more than 500,000 different electronic connectivity products for the automotive, energy, industrial, broadband communications, consumer device, healthcare, aerospace, and defense industries. TE Connectivity has a long-standing commitment to innovation and engineering

  1. TE Connectivity Finds Answers in Tomography

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

    TE Connectivity Finds Answers in Tomography TE Connectivity Finds Answers in Tomography Print Thursday, 22 August 2013 10:50 TE Connectivity is a world leader in connectivity-the $13 billion global company designs and manufactures more than 500,000 different electronic connectivity products for the automotive, energy, industrial, broadband communications, consumer device, healthcare, aerospace, and defense industries. TE Connectivity has a long-standing commitment to innovation and engineering

  2. Thermal Analysis of ZPPR High Pu Content Stored Fuel

    SciTech Connect (OSTI)

    Charles W. Solbrig; Chad Pope; Jason Andrus

    2014-09-01

    This paper estimates the temperature of high Pu content ZPPR fuel while in storage to determine the probablilty of fuel damage during storage. The Zero Power Physics Reactor (ZPPR) is an experimental reactor which has been decomissioned. It ran only at extremely low power, for testing nuclear reactor designs and was operated as a criticality facility from April 18, 1969 until decommissioned in 1990. Its fuel was manufactured in 1967 and has been in storage since the reactor was decomissioned. Heat is generated in the fuel due to Pu and Am decay and is a concern for possible fuel damage. Any damage to the cladding would be expected to lead to the fuel hydriding and oxidizing over a long period of storage as was described in the analysis of the damage to the ZPPR uranium fuel resulting in the fuel becoming unuseable and a large potential source of contamination. (Ref. Solbrig, 1994). A series of computer runs were made to scope out the range of temperatures that can occur in the ZPPR fuel in storage. The maximum calculated conservative fuel temperature is high (292 degrees C [558 degrees F]) in spite of the fact that the fuel element heat generation rates seem quite low, between 35 and 10 W for containers (called clamshells) full of fuel. However, the ZPPR storage bins, built for safeguards, are very effective insulators. The calculated clamshells and the cavity doors temperatures are also high. No record exists of people receiving skin burns by touching the cavity doors or clamshells, which indicates the computed temperatures may be higher than actual. (Note, gloves are worn when handling hotter clamshells.) Given the high calculated temperatures, a cursory measurement program was conducted to calibrate the calculated results. The measurement of bin doors, cavity doors, and clamshell temperatures would be easy to make if it were not for regulations resulting from security and potential contamination. Due to conservative assumptions in the model like high heat transfer contact resistance between contact surfaces (such as between the fuel and the clamshell), the calculated temperatures are intended to be overestimated. The temperatures of the stored fuel in a particular clamshell are dependent, among other parameters, on the distribution of fuel in the surrounding storage compartments, the heat generation rate of the fuel, and the orientation of fuel in the clamshell (parallel or perpendicular to the door). The distribution of fuel in this analysis was selected to give higher temperatures than actual distributions might give. Due to possible contamination and security concerns, fuel temperatures could not be measured but the bin doors, storage sleeve doors, and clamshell temperatures could be and were measured. The comparison of these three temperatures to the calculations indicates that the temperatures calculated with conservative assumptions are higher than the actual temperatures. This implies that the calculated fuel temperatures are higher than actual also. The maximum calculated fuel temperature with the most conservative assumptions (292 degrees C, (558 degrees F)) is significantly below the no fuel failure criterion of 600 degrees C (1,112 degrees F). Some fuel failures have occurred but these results indicate that the failures are not due to high temperatures encountered in fuel storage.

  3. Am phases in the matrix of a UPuZr alloy with Np, Am, and rare-earth elements

    SciTech Connect (OSTI)

    Janney, Dawn E.; Kennedy, J. Rory; Madden, James W.; OHolleran, Thomas P.

    2015-01-01

    Phases and microstructures in the matrix of an as-cast U-Pu-Zr alloy with 3 wt% Am, 2% Np, and 8% rare-earth elements were characterized by scanning and transmission electron microscopy. The matrix consists primarily of two phases, both of which contain Am: ?-(U, Np, Pu, Am) (~70 at% U, 5% Np, 14% Pu, 1% Am, and 10% Zr) and ?-(U, Np, Pu, Am)Zr2 (~25% U, 2% Np, 10-15% Pu, 1-2% Am, and 55-60 at% Zr). These phases are similar to those in U-Pu-Zr alloys, although the Zr content in ?-(U, Np, Pu, Am) is higher than that in ?-(U, Pu) and the Zr content in ?-(U, Np, Pu, Am)Zr2 is lower than that in ?-UZr2. Nanocrystalline actinide oxides with structures similar to UO2 occurred in some areas, but may have formed by reactions with the atmosphere during sample handling. Planar features consisting of a central zone of ?-(U, Np, Pu, Am) bracketed by zones of ?-(U, Np, Pu, Am)Zr2 bound irregular polygons ranging in size from a few micrometers to a few tens of micrometers across. The rest of the matrix consists of elongated domains of ?-(U, Np, Pu, Am) and ?-(U, Np, Pu, Am)Zr2. Each of these domains is a few tens of nanometers across and a few hundred nanometers long. The domains display strong preferred orientations involving areas a few hundred nanometers to a few micrometers across.

  4. Measurement of the 240Pu/239Pu mass ratio using a transition-edge-sensor microcalorimeter for total decay energy spectroscopy

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

    Hoover, Andrew S.; Bond, Evelyn M.; Croce, Mark P.; Holesinger, Terry G.; Kunde, Gerd J.; Rabin, Michael W.; Wolfsberg, Laura E.; Bennett, Douglas A.; Hays-Wehle, James P.; Schmidt, Dan R.; et al

    2015-02-27

    In this study, we have developed a new category of sensor for measurement of the 240Pu/239Pu mass ratio from aqueous solution samples with advantages over existing methods. Aqueous solution plutonium samples were evaporated and encapsulated inside of a gold foil absorber, and a superconducting transition-edge-sensor microcalorimeter detector was used to measure the total reaction energy (Q-value) of nuclear decays via heat generated when the energy is thermalized. Since all of the decay energy is contained in the absorber, we measure a single spectral peak for each isotope, resulting in a simple spectral analysis problem with minimal peak overlap. We foundmore » that mechanical kneading of the absorber dramatically improves spectral quality by reducing the size of radioactive inclusions within the absorber to scales below 50 nm such that decay products primarily interact with atoms of the host material. Due to the low noise performance of the microcalorimeter detector, energy resolution values of 1 keV fwhm (full width at half-maximum) at 5.5 MeV have been achieved, an order of magnitude improvement over α-spectroscopy with conventional silicon detectors. We measured the 240Pu/239Pu mass ratio of two samples and confirmed the results by comparison to mass spectrometry values. These results have implications for future measurements of trace samples of nuclear material.« less

  5. Hematological responses after inhaling {sup 238}PuO{sub 2}: An extrapolation from beagle dogs to humans

    SciTech Connect (OSTI)

    Scott, B.R.; Muggenburg, B.A.; Welsh, C.A.; Angerstein, D.A.

    1994-11-01

    The alpha emitter plutonium-238 ({sup 238}Pu), which is produced in uranium-fueled, light-water reactors, is used as a thermoelectric power source for space applications. Inhalation of a mixed oxide form of Pu is the most likely mode of exposure of workers and the general public. Occupational exposures to {sup 238}PuO{sub 2} have occurred in association with the fabrication of radioisotope thermoelectric generators. Organs and tissue at risk for deterministic and stochastic effects of {sup 238}Pu-alpha irradiation include the lung, liver, skeleton, and lymphatic tissue. Little has been reported about the effects of inhaled {sup 238}PuO{sub 2} on peripheral blood cell counts in humans. The purpose of this study was to investigate hematological responses after a single inhalation exposure of Beagle dogs to alpha-emitting {sup 238}PuO{sub 2} particles and to extrapolate results to humans.

  6. EIS-0299: Proposed Production of Plutonium-238 (Pu-238) for Use in Advanced Radioisotope Power Systems (RPS) for Space Missions

    Broader source: Energy.gov [DOE]

    This EIS is for the proposed production of plutonium-238 (Pu-238) using one or more DOE research reactors and facilities.

  7. Modeling and production of 240Am by deuteron-induced activation of a 240Pu target

    SciTech Connect (OSTI)

    Finn, Erin C.; McNamara, Bruce K.; Greenwood, Lawrence R.; Wittman, Richard S.; Soderquist, Chuck Z.; Woods, Vincent T.; VanDevender, Brent A.; Metz, Lori A.; Friese, Judah I.

    2015-02-01

    A novel reaction pathway for production of 240Am is reported. Models of reaction cross-sections in EMPIRE II suggests that deuteron-induced activation of a 240Pu target produces maximum yields of 240Am from 11.5 MeV incident deuterons. This activation had not been previously reported in the literature. A 240Pu target was activated under the modeled optimum conditions to produce 240Am. The modeled cross-section for the 240Pu(d, 2n)240Am reaction is on the order of 20-30 mbarn, but the experimentally estimated value is 5.3 0.2 mbarn. We discuss reasons for the discrepancy as well as production of other Am isotopes that contaminate the final product.

  8. Comprehensive appraisal of {sup 239+240}Pu in soils around Rocky Flats, Colorado

    SciTech Connect (OSTI)

    Litaor, M.I.; Allen, L.; Ellerbroek, D.

    1995-12-01

    Plutonium contamination of soils around Rocky Flats Environmental & Technology Site, near Golden, Colorado, resulted from past outdoor storage practices and subsequent remobilization due to inadequate cleanup practices. Until now human-health risk assessment has not been performed because of a lack of sufficient information regarding the spatial extent of {sup 239+240}Pu in soils. The purpose of this work was to elucidate the extent of plutonium contamination in surface soils, and to assess the uncertainty associated with the spatial distribution of {sup 239+240}Pu around Rocky Flats Environmental & Technology Site.

  9. He bubble coarsening by migration and coalescence in annealed Pu-Ga alloys

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: He bubble coarsening by migration and coalescence in annealed Pu-Ga alloys Citation Details In-Document Search Title: He bubble coarsening by migration and coalescence in annealed Pu-Ga alloys Authors: Jeffries, J R ; Wall, M A ; Moore, K T ; Schwartz, A J Publication Date: 2010-09-29 OSTI Identifier: 1124957 Report Number(s): LLNL-JRNL-458076 DOE Contract Number: W-7405-ENG-48 Resource Type: Journal Article Resource Relation: Journal

  10. Recycling of CdTe photovoltaic waste

    DOE Patents [OSTI]

    Goozner, Robert E.; Long, Mark O.; Drinkard, Jr., William F.

    1999-01-01

    A method for extracting and reclaiming metals from scrap CdTe photovoltaic cells and manufacturing waste by leaching the waste with a leaching solution comprising nitric acid and water, skimming any plastic material from the top of the leaching solution, separating the glass substrate from the liquid leachate and electrolyzing the leachate to separate Cd from Te, wherein the Te is deposits onto a cathode while the Cd remains in solution.

  11. TE Connectivity Finds Answers in Tomography

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

    healthcare, aerospace, and defense industries. TE Connectivity has a long-standing commitment to innovation and engineering excellence. Their products help address challenges...

  12. OM 14-66; Board's Interest Rate Remains 3 Percent for the Fourth Quarter, FY 14; 6/11/14

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

    GENERAL COUNSEL Division of Operations-Management MEMORANDUM OM 16-02 October 15, 2015 TO: All Regional Directors, Officers-in-Charge, and Resident Officers FROM: Anne Purcell, Associate General Counsel SUBJECT: NLRB ADR Program for Settling Unfair Labor Practice Cases Pending before the Board Since December 2005, the National Labor Relations Board's alternative dispute resolution (ADR) program has assisted parties in settling unfair labor practice cases pending before the Board. For parties who

  13. Recovery of UO[sub 2]/PuO[sub 2] in IFR electrorefining process

    DOE Patents [OSTI]

    Tomczuk, Z.; Miller, W.E.

    1994-10-18

    A process is described for converting PuO[sub 2] and UO[sub 2] present in an electrorefiner to the chlorides, by contacting the PuO[sub 2] and UO[sub 2] with Li metal in the presence of an alkali metal chloride salt substantially free of rare earth and actinide chlorides for a time and at a temperature sufficient to convert the UO[sub 2] and PuO[sub 2] to metals while converting Li metal to Li[sub 2]O. Li[sub 2]O is removed either by reducing with rare earth metals or by providing an oxygen electrode for transporting O[sub 2] out of the electrorefiner and a cathode, and thereafter applying an emf to the electrorefiner electrodes sufficient to cause the Li[sub 2]O to disassociate to O[sub 2] and Li metal but insufficient to decompose the alkali metal chloride salt. The U and Pu and excess lithium are then converted to chlorides by reaction with CdCl[sub 2].

  14. Hidden disorder in the α'→δ transformation of Pu-1.9 at.% Ga

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

    Jeffries, J. R.; Manley, M. E.; Wall, M. A.; Blobaum, K. J. M.; Schwartz, A. J.

    2012-06-06

    Enthalpy and entropy are thermodynamic quantities critical to determining how and at what temperature a phase transition occurs. At a phase transition, the enthalpy and temperature-weighted entropy differences between two phases are equal (ΔH=TΔS), but there are materials where this balance has not been experimentally or theoretically realized, leading to the idea of hidden order and disorder. In a Pu-1.9 at. % Ga alloy, the δ phase is retained as a metastable state at room temperature, but at low temperatures, the δ phase yields to a mixed-phase microstructure of δ- and α'-Pu. The previously measured sources of entropy associated withmore » the α'→δ transformation fail to sum to the entropy predicted theoretically. We report an experimental measurement of the entropy of the α'→δ transformation that corroborates the theoretical prediction, and implies that only about 65% of the entropy stabilizing the δ phase is accounted for, leaving a missing entropy of about 0.5 kB/atom. Some previously proposed mechanisms for generating entropy are discussed, but none seem capable of providing the necessary disorder to stabilize the δ phase. This hidden disorder represents multiple accessible states per atom within the δ phase of Pu that may not be included in our current understanding of the properties and phase stability of δ-Pu.« less

  15. Recovery of UO{sub 2}/PuO{sub 2} in IFR electrorefining process

    DOE Patents [OSTI]

    Tomczuk, Z.; Miller, W.E.

    1992-01-01

    This invention is comprised of a process for converting PuO{sub 2} and U0{sub 2} present in an electrorefiner to the chlorides, by contacting the PuO{sub 2} and U0{sub 2} with Li metal in the presence of an alkali metal chloride salt substantially free of rare earth and actinide chlorides for a time and at a temperature sufficient to convert the U0{sub 2} and PuO{sub 2} to metals while converting Li metal to Li{sub 2}O. Li{sub 2}O is removed either by reducing with rare earth metals or by providing an oxygen electrode for transporting 0{sub 2} out of the electrorefiner and a cathode, and thereafter applying an emf to the electrorefiner electrodes sufficient to cause the Li{sub 2}O to disassociate to 0{sub 2} and Li metal but insufficient to decompose the alkali metal chloride salt. The U and Pu and excess lithium are then converted to chlorides by reaction with CdCl{sub 2}.

  16. Recovery of UO.sub.2 /Pu O.sub.2 in IFR electrorefining process

    DOE Patents [OSTI]

    Tomczuk, Zygmunt (Lockport, IL); Miller, William E. (Naperville, IL)

    1994-01-01

    A process for converting PuO.sub.2 and UO.sub.2 present in an electrorefiner to the chlorides, by contacting the PuO.sub.2 and UO.sub.2 with Li metal in the presence of an alkali metal chloride salt substantially free of rare earth and actinide chlorides for a time and at a temperature sufficient to convert the UO.sub.2 and PuO.sub.2 to metals while converting Li metal to Li.sub.2 O. Li.sub.2 O is removed either by reducing with rare earth metals or by providing an oxygen electrode for transporting O.sub.2 out of the electrorefiner and a cathode, and thereafter applying an emf to the electrorefiner electrodes sufficient to cause the Li.sub.2 O to disassociate to O.sub.2 and Li metal but insufficient to decompose the alkali metal chloride salt. The U and Pu and excess lithium are then converted to chlorides by reaction with CdCl.sub.2.

  17. Understanding oxygen adsorption on 9.375 at. % Ga-stabilized ?-Pu (111) surface: A DFT study

    SciTech Connect (OSTI)

    Hernandez, Sarah C.; Wilkerson, Marianne P.; Huda, Muhammad N.

    2015-08-30

    Plutonium (Pu) metal reacts rapidly in the presence of oxygen (O), resulting in an oxide layer that will eventually have an olive green rust appearance over time. Recent experimental work suggested that the incorporation of gallium (Ga) as an alloying impurity to stabilize the highly symmetric high temperature ?-phase lattice may also provide resistance against corrosion/oxidation of plutonium. In this paper, we modeled a 9.375 at. % Ga stabilized ?-Pu (111) surface and investigated adsorption of atomic O using all-electron density functional theory. Key findings revealed that the O bonded strongly to a Pu-rich threefold hollow fcc site with a chemisorption energy of 5.06 eV. Migration of the O atom to a Pu-rich environment was also highly sensitive to the surface chemistry of the PuGa surface; when the initial on-surface O adsorption site included a bond to a nearest neighboring Ga atom, the O atom relaxed to a Ga deficient environment, thus affirming the O preference for Pu. Only one calculated final on-surface O adsorption site included a Ga-O bond, but this chemisorption energy was energetically unfavorable. Chemisorption energies for interstitial adsorption sites that included a Pu or Pu-Ga environment suggested that over-coordination of the O atom was energetically unfavorable as well. Electronic structure properties of the on-surface sites, illustrated by the partial density of states, implied that the Ga 4p states indirectly but strongly influenced the Pu 6d states strongly to hybridize with the O 2p states, while also weakly influenced the Pu 5f states to hybridize with the O 2p states, even though Ga was not participating in bonding with O.

  18. CdTe devices and method of manufacturing same

    DOE Patents [OSTI]

    Gessert, Timothy A.; Noufi, Rommel; Dhere, Ramesh G.; Albin, David S.; Barnes, Teresa; Burst, James; Duenow, Joel N.; Reese, Matthew

    2015-09-29

    A method of producing polycrystalline CdTe materials and devices that incorporate the polycrystalline CdTe materials are provided. In particular, a method of producing polycrystalline p-doped CdTe thin films for use in CdTe solar cells in which the CdTe thin films possess enhanced acceptor densities and minority carrier lifetimes, resulting in enhanced efficiency of the solar cells containing the CdTe material are provided.

  19. The Precipitation of Sb2Te3 in Sb-rich AgSbTe2 via the Intermediate...

    Office of Scientific and Technical Information (OSTI)

    Title: The Precipitation of Sb2Te3 in Sb-rich AgSbTe2 via the Intermediate Phase (AgSb)3Te4. Abstract not provided. Authors: Sugar, Joshua Daniel ; Medlin, Douglas L. Publication ...

  20. Post-Growth Annealing of Bridgman-grown CdZnTe and CdMnTe Crystals...

    Office of Scientific and Technical Information (OSTI)

    Title: Post-Growth Annealing of Bridgman-grown CdZnTe and CdMnTe Crystals for Room-temperature Nuclear Radiation Detectors Bridgman-grown cadmium zinc telluride (CdZnTe or CZT) and ...

  1. High Performance Zintl Phase TE Materials with Embedded Particles...

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

    Performance Zintl Phase TE Materials with Embedded Particles High Performance Zintl Phase TE Materials with Embedded Particles Presents results from embedding nanoparticles in...

  2. High performance Zintl phase TE materials with embedded nanoparticles...

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

    performance Zintl phase TE materials with embedded nanoparticles High performance Zintl phase TE materials with embedded nanoparticles Performance of zintl phase thermoelectric...

  3. Understanding oxygen adsorption on 9.375 at. % Ga-stabilized δ-Pu (111) surface: A DFT study

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

    Hernandez, Sarah C.; Wilkerson, Marianne P.; Huda, Muhammad N.

    2015-08-30

    Plutonium (Pu) metal reacts rapidly in the presence of oxygen (O), resulting in an oxide layer that will eventually have an olive green rust appearance over time. Recent experimental work suggested that the incorporation of gallium (Ga) as an alloying impurity to stabilize the highly symmetric high temperature δ-phase lattice may also provide resistance against corrosion/oxidation of plutonium. In this paper, we modeled a 9.375 at. % Ga stabilized δ-Pu (111) surface and investigated adsorption of atomic O using all-electron density functional theory. Key findings revealed that the O bonded strongly to a Pu-rich threefold hollow fcc site with amore » chemisorption energy of –5.06 eV. Migration of the O atom to a Pu-rich environment was also highly sensitive to the surface chemistry of the Pu–Ga surface; when the initial on-surface O adsorption site included a bond to a nearest neighboring Ga atom, the O atom relaxed to a Ga deficient environment, thus affirming the O preference for Pu. Only one calculated final on-surface O adsorption site included a Ga-O bond, but this chemisorption energy was energetically unfavorable. Chemisorption energies for interstitial adsorption sites that included a Pu or Pu-Ga environment suggested that over-coordination of the O atom was energetically unfavorable as well. Electronic structure properties of the on-surface sites, illustrated by the partial density of states, implied that the Ga 4p states indirectly but strongly influenced the Pu 6d states strongly to hybridize with the O 2p states, while also weakly influenced the Pu 5f states to hybridize with the O 2p states, even though Ga was not participating in bonding with O.« less

  4. Use of PuBe source to simulate neutron-induced single event upsets in static RAMS

    SciTech Connect (OSTI)

    Normand, E.; Wert, J.L.; Doherty, W.R.; Oberg, D.L.; Measel, P.R.; Criswell, T.L.

    1988-12-01

    Neutron induced single event upsets were measured in static memory devices using a 10 curie PuBe source. The PuBe source conservatively overestimates the spectrum of fast neutrons emitted by a radioisotope thermoelectric generator (RTG). For the 93L422, the neutron-induced upset rate compared favorably with calculated values derived using the burst generation concept. By accounting for the production of the ionizing particles by the PuBe and RTG neutron spectra, convenient upper bound SEU upset rates for memory devices near an RTG can be derived.

  5. Recycling of CdTe photovoltaic waste

    DOE Patents [OSTI]

    Goozner, R.E.; Long, M.O.; Drinkard, W.F. Jr.

    1999-04-27

    A method for extracting and reclaiming metals from scrap CdTe photovoltaic cells and manufacturing waste by leaching the metals in dilute nitric acid, leaching the waste with a leaching solution comprising nitric acid and water, skimming any plastic material from the top of the leaching solution, separating the glass substrate from the liquid leachate, adding a calcium containing base to the leachate to precipitate Cd and Te, separating the precipitated Cd and Te from the leachate, and recovering the calcium-containing base. 3 figs.

  6. Recycling of CdTe photovoltaic waste

    DOE Patents [OSTI]

    Goozner, Robert E.; Long, Mark O.; Drinkard, Jr., William F.

    1999-04-27

    A method for extracting and reclaiming metals from scrap CdTe photovoltaic cells and manufacturing waste by leaching the metals in dilute nitric acid, leaching the waste with a leaching solution comprising nitric acid and water, skimming any plastic material from the top of the leaching solution, separating the glass substrate from the liquid leachate, adding a calcium containing base to the leachate to precipitate Cd and Te, separating the precipitated Cd and Te from the leachate, and recovering the calcium-containing base.

  7. High performance Zintl phase TE materials with embedded nanoparticles |

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

    Department of Energy performance Zintl phase TE materials with embedded nanoparticles High performance Zintl phase TE materials with embedded nanoparticles Performance of zintl phase thermoelectric materials with embedded particles are evaluated PDF icon shakouri.pdf More Documents & Publications High performance Zintl phase TE materials with embedded nanoparticles High Performance Zintl Phase TE Materials with Embedded Particles Thermoelectrics Partnership: High Performance

  8. Ostwald Ripening and Its Effect on PuO2 Particle Size in Hanford Tank Waste

    SciTech Connect (OSTI)

    Delegard, Calvin H.

    2011-09-29

    Between 1944 and 1989, the Hanford Site produced 60 percent (54.5 metric tons) of the United States weapons plutonium and produced an additional 12.9 metric tons of fuels-grade plutonium. High activity wastes, including plutonium lost from the separations processes used to isolate the plutonium, were discharged to underground storage tanks during these operations. Plutonium in the Hanford tank farms is estimated to be {approx}700 kg but may be up to {approx}1000 kg. Despite these apparent large quantities, the average plutonium concentration in the {approx}200 million liter tank waste volume is only about 0.003 grams per liter ({approx}0.0002 wt%). The plutonium is largely associated with low solubility metal hydroxide/oxide sludges where its low concentration and intimate mixture with neutron-absorbing elements (e.g., iron) are credited in nuclear criticality safety. However, concerns have been expressed that plutonium, in the form of plutonium hydrous oxide, PuO{sub 2} {center_dot} xH{sub 2}O, could undergo sufficient crystal growth through Ostwald ripening in the alkaline tank waste to potentially be separable from neutron absorbing constituents by settling or sedimentation. It was found that plutonium that entered the alkaline tank waste by precipitation through neutralization from acid solution is initially present as 2- to 3-nm (0.002- to 0.003-{mu}m) scale PuO{sub 2} {center_dot} xH{sub 2}O crystallite particles and grows from that point at exceedingly slow rates, posing no risk to physical segregation. These conclusions are reached by both general considerations of Ostwald ripening and specific observations of the behaviors of PuO{sub 2} and PuO{sub 2} {center_dot} xH{sub 2}O upon aging in alkaline solution.

  9. The reduction of Np(VI) and Pu(VI) by organic chelating agents.

    SciTech Connect (OSTI)

    Reed, D.T.; Aase, S.B.; Banaszak, J.E.

    1998-03-19

    The reduction of NpO{sup 2+} and PuO{sub 2}{sup 2+} by oxalate. citrate, and ethylenediaminetetraacetic acid (EDTA) was investigated in low ionic strength media and brines. This was done to help establish the stability of the An(VI) oxidation state in the presence of organic complexants. The stability of the An(VI) oxidation state depended on the pH and relative strength of the various oxidation state-specific complexes. At low ionic strength and pH 6, NpO{sub 2}O{sup 2+} was rapidly reduced to form NpO{sub 2}{sup +} organic complexes. At longer times, Np(IV) organic complexes were observed in the presence of citrate. PuO{sub 2}{sup 2+} was predominantly reduced to Pu{sup 4+}, resulting in the formation of organic complexes or polymeric/hydrolytic precipitates. The relative rates of reduction to the An(V) complex were EDTA > citrate > oxalate. Subsequent reduction to An(IV) complexes, however, occurred in the following order: citrate > EDTA > oxalate because of the stability of the An(V)-EDTA complex. The presence of organic complexants led to the rapid reduction of NpO{sub 2}{sup 2+} and PuO{sub 2}P{sup 2+} in G-seep brine at pHs 5 and 7. At pHs 8 and 10 in ERDA-6 brine, carbonate and hydrolytic complexes predominated and slowed down or prevented the reduction of An(VI) by the organics present.

  10. 6th US-Russian Pu Science Workshop Lawrence Livermore National Laboratory

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

    US-Russian Pu Science Workshop Lawrence Livermore National Laboratory University of California, Livermore, California July 14 and 15, 2006 Local Chairs: Michael Fluss, James Tobin, Adam Schwartz LLNL, Livermore, USA Alexander V. Petrovtsev, RFNC * VNIITF, Snezhinsk, Russia Boris A. Nadykto, RFNC * VNIIEF, Sarov, Russia Lidia F. Timofeeva, VNIINM, Moscow, Russia Siegfried S. Hecker, (Luis Morales POC) LANL, Los Alamos, USA Valentin E. Arkhipov, IMP, Ural Branch of RAS, Yekaterinburg, Russia This

  11. Separate effects identification via casting process modeling for experimental measurement of UPuZr alloys

    SciTech Connect (OSTI)

    J. Crapps; D. S. DeCroix; J. D. Galloway; D. A. Korzekwa; R. Aikin; R. Fielding; R. Kennedy; C. Unal

    2013-11-01

    Computational simulations of gravity casting processes for metallic UPuZr nuclear fuel rods have been performed using a design-of-experiments technique to determine the fluid flow, liquid heat transfer, and solid heat transfer parameters which most strongly influence the process solidification speed and fuel rod porosity. The results are used to make recommendations for the best investment of experimental time and effort to measure process parameters.

  12. Phonon dispersion curves determination in (delta)-phase Pu-Ga alloys

    SciTech Connect (OSTI)

    Wong, J; Clatterbuck, D; Occelli, F; Farber, D; Schwartz, A; Wall, M; Boro, C; Krisch, M; Beraud, A; Chiang, T; Xu, R; Hong, H; Zschack, P; Tamura, N

    2006-02-07

    We have designed and successfully employed a novel microbeam on large grain sample concept to conduct high resolution inelastic x-ray scattering (HRIXS) experiments to map the full phonon dispersion curves of an fcc {delta}-phase Pu-Ga alloy. This approach obviates experimental difficulties with conventional inelastic neutron scattering due to the high absorption cross section of the common {sup 239}Pu isotope and the non-availability of large (mm size) single crystal materials for Pu and its alloys. A classical Born von-Karman force constant model was used to model the experimental results, and no less than 4th nearest neighbor interactions had to be included to account for the observation. Several unusual features including, a large elastic anisotropy, a small shear elastic modulus, (C{sub 11}-C{sub 12})/2, a Kohn-like anomaly in the T{sub 1}[011] branch, and a pronounced softening of the T[111] branch towards the L point in the Brillouin are found. These features may be related to the phase transitions of plutonium and to strong coupling between the crystal structure and the 5f valence instabilities. Our results represent the first full phonon dispersions ever obtained for any Pu-bearing material, thus ending a 40-year quest for this fundamental data. The phonon data also provide a critical test for theoretical treatments of highly correlated 5f electron systems as exemplified by recent dynamical mean field theory (DMFT) calculations for {delta}-plutonium. We also conducted thermal diffuse scattering experiments to study the T(111) dispersion at low temperatures with an attempt to gain insight into bending of the T(111) branch in relationship to the {delta} {yields} {alpha}{prime} transformation.

  13. Microsoft Word - Template_SLAC Proprietary Use Agreement_PU 11_14_13

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

    PU 11/14/2013 1 The Department of Energy has opted to utilize the following agreement for Designated Proprietary User Facilities transactions. Because these transactions are widespread across Departmental facilities, uniformity in agreement terms is desirable. Except for the *** provisions, minor modifications to the terms of this agreement may be made by CONTRACTOR, but any changes to the *** provisions or substantive changes to the non *** provisons will require approval by the DOE Contracting

  14. NMIS With Gamma Spectrometry for Attributes of Pu and HEU, Explosives and Chemical Agents

    SciTech Connect (OSTI)

    Mihalczo, J. T.; Mattingly, J. K.; Mullens, J. A.; Neal, J. S.

    2002-05-10

    The concept for the system described herein is an active/passive Nuclear Materials Identification System{sup 2} (NMIS) that incorporates gamma ray spectrometry{sup 3}. This incorporation of gamma ray spectrometry would add existing capability into this system. This Multiple Attribute System can determine a wide variety of attributes for Pu and highly enriched uranium (HEU) of which a selected subset could be chosen. This system can be built using commercial off the shelf (COTS) components. NMIS systems are at All-Russian Scientific Research Institute of Experimental Physics (VNIIEF) and Russian Federal Nuclear Center Institute of Technical Physics, (VNIITF) and measurements with Pu have been performed at VNIIEF and analyzed successfully for mass and thickness of Pu. NMIS systems are being used successfully for HEU at the Y-12 National Security Complex. The use of active gamma ray spectrometry for high explosive HE and chemical agent detection is a well known activation analysis technique, and it is incorporated here. This report describes the system, explains the attribute determination methods for fissile materials, discusses technical issues to be resolved, discusses additional development needs, presents a schedule for building from COTS components, and assembly with existing components, and discusses implementation issues such as lack of need for facility modification and low radiation exposure.

  15. Thermodynamic and Transport Properties of YTe3, LaTe3 and CeTe3

    SciTech Connect (OSTI)

    Ru, N.

    2011-08-19

    Measurements of heat capacity, susceptibility, and electrical resistivity are presented for single crystals of the charge density wave compounds YTe{sub 3}, LaTe{sub 3}, and CeTe{sub 3}. The materials are metallic to low temperatures, but have a small density of states due to the charge density wave gapping large portions of the Fermi surface. CeTe{sub 3} is found to be a weak Kondo lattice, with an antiferromagnetic ground state and T{sub N} = 2.8 K. The electrical resistivity of all three compounds is highly anisotropic, confirming the weak dispersion perpendicular to Te planes predicted by band structure calculations.

  16. The new Mercedes-Benz OM 904 LA light heavy-duty diesel engine for class 6 trucks

    SciTech Connect (OSTI)

    Schittler, M.; Bergmann, H.; Flathmann, K.

    1996-09-01

    As part of a comprehensive strategic product initiative the most important commercial vehicle manufacturer--Mercedes-Benz AG--is step by step renewing its entire product range. This primarily refers to the heart of the vehicles--the engine. After the OM 457 LA, which was developed together with DDC for the special American market demands and which is produced and sold in the US by DDC under the label Series 55, has had its premiere in Freightliner`s Century Class, the OM 904 LA will now follow in the light commercial vehicle class. This engine has a completely new concept of a direct-injection, highly sophisticated turbocharged four-cylinder in-line engine with air-to-air intercooler, whose main characteristics can be outlined by the terms multi-valve technology, high-pressure injection via unit pumps and electronic engine control. This small engine has several interesting features, which--up to now--were only known from class 8 engines. In addition to fulfilling increased customer demands with regard to long service life, easy maintenance, reliability and economy, great attention was paid during the design of the engine to not only fulfill the global regulations, but also account for sufficient potential to comply with further aggravations to be expected. The most important design features and the attained engine ratings are indicated and explained in detail.

  17. Post-Growth Annealing of Bridgman-grown CdZnTe and CdMnTe Crystals for

    Office of Scientific and Technical Information (OSTI)

    Room-temperature Nuclear Radiation Detectors (Journal Article) | SciTech Connect Post-Growth Annealing of Bridgman-grown CdZnTe and CdMnTe Crystals for Room-temperature Nuclear Radiation Detectors Citation Details In-Document Search Title: Post-Growth Annealing of Bridgman-grown CdZnTe and CdMnTe Crystals for Room-temperature Nuclear Radiation Detectors Bridgman-grown cadmium zinc telluride (CdZnTe or CZT) and cadmium manganese telluride (CdMnTe or CMT) crystals often have Te inclusions that

  18. GaTe semiconductor for radiation detection

    DOE Patents [OSTI]

    Payne, Stephen A.; Burger, Arnold; Mandal, Krishna C.

    2009-06-23

    GaTe semiconductor is used as a room-temperature radiation detector. GaTe has useful properties for radiation detectors: ideal bandgap, favorable mobilities, low melting point (no evaporation), non-hygroscopic nature, and availability of high-purity starting materials. The detector can be used, e.g., for detection of illicit nuclear weapons and radiological dispersed devices at ports of entry, in cities, and off shore and for determination of medical isotopes present in a patient.

  19. Diamond Based TE Materials | Department of Energy

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

    Diamond Based TE Materials Diamond Based TE Materials 2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C. PDF icon pm032_gruen_2010_p.pdf More Documents & Publications Thermoelectric Nanocarbon Ensembles DOE Vehicle Technologies Program 2009 Merit Review Report - Propulsion Materials Enhancing the Figure-of-Merit in Half-Heuslers for Vehicle Waste Heat Recovery

  20. First-principles study of the Kondo physics of a single Pu impurity in a Th host

    SciTech Connect (OSTI)

    Zhu, Jian -Xin; Albers, R. C.; Haule, K.; Wills, J. M.

    2015-04-23

    Based on its condensed-matter properties, crystal structure, and metallurgy, which includes a phase diagram with six allotropic phases, plutonium is one of the most complicated pure elements in its solid state. Its anomalous properties, which are indicative of a very strongly correlated state, are related to its special position in the periodic table, which is at the boundary between the light actinides that have itinerant 5f electrons and the heavy actinides that have localized 5f electrons. As a foundational study to probe the role of local electronic correlations in Pu, we use the local-density approximation together with a continuous-time quantum Monte Carlo simulation to investigate the electronic structure of a single Pu atom that is either substitutionally embedded in the bulk and or adsorbed on the surface of a Th host. This is a simpler case than the solid phases of Pu metal. With the Pu impurity atom we have found a Kondo resonance peak, which is an important signature of electronic correlations, in the local density of states around the Fermi energy. We show that the peak width of this resonance is narrower for Pu atoms at the surface of Th than for those in the bulk due to a weakened Pu - 5f hybridization with the ligands at the surface.

  1. Ground-state wave function of plutonium in PuSb as determined via x-ray magnetic circular dichroism

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

    Janoschek, M.; Haskel, D.; Fernandez-Rodriguez, J.; van Veenendaal, M.; Rebizant, J.; Lander, G. H.; Zhu, J. -X.; Thompson, J. D.; Bauer, E. D.

    2015-01-14

    Measurements of x-ray magnetic circular dichroism (XMCD) and x-ray absorption near-edge structure (XANES) spectroscopy at the Pu M₄,₅ edges of the ferromagnet PuSb are reported. Using bulk magnetization measurements and a sum rule analysis of the XMCD spectra, we determine the individual orbital [μL = 2.8(1)μB/Pu] and spin moments [μS = –2.0(1)μB/Pu] of the Pu 5f electrons for the first time. Atomic multiplet calculations of the XMCD and XANES spectra reproduce well the experimental data and are consistent with the experimental value of the spin moment. These measurements of Lz and Sz are in excellent agreement with the values thatmore » have been extracted from neutron magnetic form factor measurements, and confirm the local character of the 5f electrons in PuSb. We demonstrate that a split M₅ as well as a narrow M₄ XMCD signal may serve as a signature of 5f electron localization in actinide compounds.« less

  2. Ground-state wave function of plutonium in PuSb as determined via x-ray magnetic circular dichroism

    SciTech Connect (OSTI)

    Janoschek, M.; Haskel, D.; Fernandez-Rodriguez, J.; van Veenendaal, M.; Rebizant, J.; Lander, G. H.; Zhu, J. -X.; Thompson, J. D.; Bauer, E. D.

    2015-01-01

    Measurements of x-ray magnetic circular dichroism (XMCD) and x-ray absorption near-edge structure (XANES) spectroscopy at the Pu M?,? edges of the ferromagnet PuSb are reported. Using bulk magnetization measurements and a sum rule analysis of the XMCD spectra, we determine the individual orbital [?L = 2.8(1)?B/Pu] and spin moments [?S = ?2.0(1)?B/Pu] of the Pu 5f electrons for the first time. Atomic multiplet calculations of the XMCD and XANES spectra reproduce well the experimental data and are consistent with the experimental value of the spin moment. These measurements of ?Lz? and ?Sz? are in excellent agreement with the values that have been extracted from neutron magnetic form factor measurements, and confirm the local character of the 5f electrons in PuSb. Finally, we demonstrate that a split M? as well as a narrow M? XMCD signal may serve as a signature of 5f electron localization in actinide compounds.

  3. Validation of MCNP6.1 for Criticality Safety of Pu-Metal, -Solution, and -Oxide Systems

    SciTech Connect (OSTI)

    Kiedrowski, Brian C.; Conlin, Jeremy Lloyd; Favorite, Jeffrey A.; Kahler, III, Albert C.; Kersting, Alyssa R.; Parsons, Donald K.; Walker, Jessie L.

    2014-05-13

    Guidance is offered to the Los Alamos National Laboratory Nuclear Criticality Safety division towards developing an Upper Subcritical Limit (USL) for MCNP6.1 calculations with ENDF/B-VII.1 nuclear data for three classes of problems: Pu-metal, -solution, and -oxide systems. A benchmark suite containing 1,086 benchmarks is prepared, and a sensitivity/uncertainty (S/U) method with a generalized linear least squares (GLLS) data adjustment is used to reject outliers, bringing the total to 959 usable benchmarks. For each class of problem, S/U methods are used to select relevant experimental benchmarks, and the calculational margin is computed using extreme value theory. A portion of the margin of sub criticality is defined considering both a detection limit for errors in codes and data and uncertainty/variability in the nuclear data library. The latter employs S/U methods with a GLLS data adjustment to find representative nuclear data covariances constrained by integral experiments, which are then used to compute uncertainties in keff from nuclear data. The USLs for the classes of problems are as follows: Pu metal, 0.980; Pu solutions, 0.973; dry Pu oxides, 0.978; dilute Pu oxide-water mixes, 0.970; and intermediate-spectrum Pu oxide-water mixes, 0.953.

  4. First-principles study of the Kondo physics of a single Pu impurity in a Th host

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

    Zhu, Jian -Xin; Albers, R. C.; Haule, K.; Wills, J. M.

    2015-04-23

    Based on its condensed-matter properties, crystal structure, and metallurgy, which includes a phase diagram with six allotropic phases, plutonium is one of the most complicated pure elements in its solid state. Its anomalous properties, which are indicative of a very strongly correlated state, are related to its special position in the periodic table, which is at the boundary between the light actinides that have itinerant 5f electrons and the heavy actinides that have localized 5f electrons. As a foundational study to probe the role of local electronic correlations in Pu, we use the local-density approximation together with a continuous-time quantummore » Monte Carlo simulation to investigate the electronic structure of a single Pu atom that is either substitutionally embedded in the bulk and or adsorbed on the surface of a Th host. This is a simpler case than the solid phases of Pu metal. With the Pu impurity atom we have found a Kondo resonance peak, which is an important signature of electronic correlations, in the local density of states around the Fermi energy. We show that the peak width of this resonance is narrower for Pu atoms at the surface of Th than for those in the bulk due to a weakened Pu - 5f hybridization with the ligands at the surface.« less

  5. Stability constants important to the understanding of plutonium in environmental waters, hydroxy and carbonate complexation of PuO{sub 2}{sup +}

    SciTech Connect (OSTI)

    Bennett, D A

    1990-04-20

    The formation constants for the reactions PuO{sub 2}{sup +} + H{sub 2}O = PuO{sub 2}(OH) + H{sup +} and PuO{sub 2}{sup +} + CO{sub 3}{sup 2} = PuO{sub 2}(CO{sub 3}){sup {minus}} were determined in aqueous sodium perchlorate solutions by laser-induced photoacoustic spectroscopy. The molar absorptivity of the PuO{sub 2}{sup +} band at 569 nm decreased with increasing hydroxide concentration. Similarly, spectral changes occurred between 540 and 580 nm as the carbonate concentration was increased. The absorption data were analyzed by the non-linear least-squares program SQUAD to yield complexation constants. Using the specific ion interaction theory, both complexation constants were extrapolated to zero ionic strength. These thermodynamic complexation constants were combined with the oxidation-reduction potentials of Pu to obtain Eh versus pH diagrams. 120 refs., 35 figs., 12 tabs.

  6. Improved laboratory assays of Pu and U for SRP purification and finishing processes

    SciTech Connect (OSTI)

    Holland, M K; Dorsett, R S

    1986-01-01

    Significant improvements have been made in routine assay techniques for uranium and plutonium as part of an effort to improve accountability at the Savannah River Plant (SRP). Emphasis was placed on input/output accountability points and key physical inventory tanks associated with purification and finishing processes. Improvements were made in existing assay methods; new methods were implemented; and the application of these methods was greatly expanded. Prior to assays, samples were validated via density measurements. Digital density meters precise to four, five, and six decimal places were used to meet specific requirements. Improved plutonium assay techniques are now in routine use: controlled-potential coulometry, ion-exchange coulometry, and Pu(III) diode-array spectrophotometry. A new state-of-the-art coulometer was fabricated and used to ensure maximum accuracy in verifying standards and in measuring plutonium in product streams. The diode-array spectrophotometer for Pu(III) measurements was modified with fiber optics to facilitate remote measurements; rapid, precise measurements made the technique ideally suited for high-throughput assays. For uranium assays, the isotope-dilution mass spectrometric (IDMS) method was converted to a gravimetric basis. The IDMS method and the existing Davies-Gray titration (gravimetric basis) have met accountability requirements for uranium. More recently, a Pu(VI) diode-array spectrophotometric method was used on a test basis to measure plutonium in shielded-cell input accountability samples. In addition, tests to measure uranium via diode-array spectrophotometry were initiated. This rapid, precise method will replace IDMS for certain key sample points.

  7. Post-Irradiation Examination of 237Np Targets for 238Pu Production

    SciTech Connect (OSTI)

    Morris, Robert Noel [ORNL; Baldwin, Charles A [ORNL; Hobbs, Randy W [ORNL; Schmidlin, Joshua E [ORNL

    2015-01-01

    Oak Ridge National Laboratory is recovering the US 238Pu production capability and the first step in the process has been to evaluate the performance of a 237Np target cermet pellet encased in an aluminum clad. The process proceeded in 3 steps; the first step was to irradiate capsules of single pellets composed of NpO2 and aluminum power to examine their shrinkage and gas release. These pellets were formed by compressing sintered NpO2 and aluminum powder in a die at high pressure followed by sintering in a vacuum furnace. Three temperatures were chosen for sintering the solution precipitated NpO2 power used for pellet fabrication. The second step was to irradiate partial targets composed of 8 pellets in a semi-prototypical arrangement at the two best performing sintering temperatures to determine which temperature gave a pellet that performed the best under the actual planned irradiation conditions. The third step was to irradiate ~50 pellets in an actual target configuration at design irradiation conditions to assess pellet shrinkage and gas release, target heat transfer, and dimensional stability. The higher sintering temperature appeared to offer the best performance after one cycle of irradiation by having the least shrinkage, thus keeping the heat transfer gap between the pellets and clad small minimizing the pellet operating temperature. The final result of the testing was a target that can meet the initial production goals, satisfy the reactor safety requirements, and can be fabricated in production quantities. The current focus of the program is to verify that the target can be remotely dissembled, the pellets dissolved, and the 238Pu recovered. Tests are being conducted to examine these concerns and to compare results to code predictions. Once the performance of the full length targets has been quantified, the pellet 237Np loading will be revisited to determine if it can be increased to increase 238Pu production.

  8. Modeling of constituent redistribution in U-Pu-Zr metallic fuel.

    SciTech Connect (OSTI)

    Kim, Y. S.; Hofman, G. L.; Hayes, S. L.; Yacout, A. M.; Nuclear Engineering Division; INL

    2006-12-01

    A computer model was developed to analyze constituent redistribution in U-Pu-Zr metallic nuclear fuels. Diffusion and thermochemical properties were parametrically determined to fit the postirradiation data from a fuel test performed in the Experimental Breeder Reactor II (EBR-II). The computer model was used to estimate redistribution profiles of fuels proposed for the conceptual designs of small modular fast reactors. The model results showed that the level of redistribution of the fuel constituents of the designs was similar to the measured data from EBR-II.

  9. Possible experimental evidence for the presence of double octupole states in {sup 240}Pu

    SciTech Connect (OSTI)

    Pascu, S.; Spieker, M.; Bucurescu, D.; Faestermann, T.; Hertenberger, R.; Skalacki, S.; Weber, S.; Wirth, H. F.; Zamfir, N. V.; Zilges, A.

    2012-10-20

    Excited states in the {sup 240}Pu nucleus have been studied by means of the (p,t) reaction using the Q3D spectrometer and the focal plane detector from Munich. The comparison between experimental angular distributions and the DWBA calculations allowed the extraction of relative two-neutron transfer strengths. These observables may reveal important information about the structure of different states. The experimental two neutron strength for the 0{sup +}{sub 2} and 0{sup +}{sub 3} states is found in good agreement with the predictions of the IBA model, confirming the double octupole nature for the 0{sup +}{sub 2} state proposed in the previous studies.

  10. DOE plutonium disposition study: Pu consumption in ALWRs. Volume 2, Final report

    SciTech Connect (OSTI)

    Not Available

    1993-05-15

    The Department of Energy (DOE) has contracted with Asea Brown Boveri-Combustion Engineering (ABB-CE) to provide information on the capability of ABB-CE`s System 80 + Advanced Light Water Reactor (ALWR) to transform, through reactor burnup, 100 metric tonnes (MT) of weapons grade plutonium (Pu) into a form which is not readily useable in weapons. This information is being developed as part of DOE`s Plutonium Disposition Study, initiated by DOE in response to Congressional action. This document Volume 2, provides a discussion of: Plutonium Fuel Cycle; Technology Needs; Regulatory Considerations; Cost and Schedule Estimates; and Deployment Strategy.

  11. Llr. Norgnn of the St. Louis office tolepbonod Dr. ;PuAuff mcently

    Office of Legacy Management (LM)

    Llr. Norgnn of the St. Louis office tolepbonod Dr. ;PuAuff mcently rtxpeetlng pemlasion to !wu mpmaentatfoee of Uallinckrodt visit 03% to review rare earth smparatlon tmkniquas. Their lntsmst In purev binstrIal In that they hop to indsti- preilnotlon '- emparntlon of thssae elwnts., Dr. %odnUf oheckad ritli Paul -1. : '/I .._ ,,,. . . w!w was will- to ao"rrlon~vit~~'thoir,Pisiffirg.~e Laboratory sliax he did not feel that it lzpliad 8.pmferentia.l tmabmnt of KalllncJwodt. Subsquently, Dr.

  12. 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.

  13. Study on reduction and back extraction of Pu(IV) by urea derivatives in nitric acid conditions

    SciTech Connect (OSTI)

    Ye, G.A.; Xiao, S.T.; Yan, T.H.; Lin, R.S.; Zhu, Z.W.

    2013-07-01

    The reduction kinetics of Pu(IV) by hydroxyl-semicarbazide (HSC), hydroxyurea (HU) and di-hydroxyurea (DHU) in nitric acid solutions were investigated separately with adequate kinetic equations. In addition, counter-current cascade experiments were conducted for Pu split from U in nitric acid media using three kinds of reductant, respectively. The results show that urea derivatives as a kind of novel salt-free reductant can reduce Pu(IV) to Pu(III) rapidly in the nitric acid solutions. The stripping experimental results showed that Pu(IV) in the organic phase can be stripped rapidly to the aqueous phase by the urea derivatives, and the separation factors of plutonium /uranium can reach more than 10{sup 4}. This indicates that urea derivatives is a kind of promising salt-free agent for uranium/plutonium separation. In addition, the complexing effect of HSC with Np(IV) was revealed, and Np(IV) can be back-extracted by HSC with a separation factor of about 20.

  14. Summary of EXAFS results on Cd-doped PuRhIn5 (Technical Report) | SciTech

    Office of Scientific and Technical Information (OSTI)

    Connect Summary of EXAFS results on Cd-doped PuRhIn5 Citation Details In-Document Search Title: Summary of EXAFS results on Cd-doped PuRhIn5 Authors: Booth, C H ; Bauer, E D ; Tobin, J G Publication Date: 2014-06-12 OSTI Identifier: 1149554 Report Number(s): LLNL-TR-657137 DOE Contract Number: DE-AC52-07NA27344 Resource Type: Technical Report Research Org: Lawrence Livermore National Laboratory (LLNL), Livermore, CA Sponsoring Org: USDOE Country of Publication: United States Language:

  15. Effect and optimization of CdS/CdTe interdiffusion on CdTe electrical properties and CdS/CdTe cell performance

    SciTech Connect (OSTI)

    Song, W.; Mao, D.; Kaydanov, V.; Ohno, T.R.; Trefny, J.V.; Levi, D.H.; Johnston, S. McCandless, B.E.

    1999-03-01

    We have investigated the effect of the CdS/CdTe interdiffusion on the properties of the CdTe films and the CdS/CdTe cell performance. Sulfur (S) diffusion into the CdTe films leads to a decreased defect density in the films, improvement of cell performance, and possibly to the increase of the carrier lifetime in the films. Cell performance is improved with the increase of the amount of S in the CdTe films. S diffusion into CdTe also deteriorates the uniformity of the CdS window layers, resulting in worse cell performance. Based on this study, we propose a processing method to improve cell performance. {copyright} {ital 1999 American Institute of Physics.}

  16. Radioecologycal study of {sup 239/240}Pu in Bangka Island and Muria Peninsula: Determination of {sup 239/240}Pu in marine sediment and seawater as part of baseline data collecting for sitting of candidates of first Indonesia NPP

    SciTech Connect (OSTI)

    Suseno, Heny; Wisnubroto, Djarot S.

    2014-03-24

    Radioisotope Pu-239/240 are alpha emitting nuclides important indicators of radioactive contamination of the marine environment. Global fallout is the main source of plutonium in the marine environment. There are very limited study on {sup 239/240}Pu in Indonesia coastal environments. The data of this radioisotopes is needed for baseline data of nuclear power plant (NPP) site candidates both in Bangka Island and Muria Peninsula. Bottom sediments play an important role in radioecological studies of the marine environment because a large proportion of radioactive substances entering the sea is adsorbed over time onto suspended particulate matter and deposited in sediments. Plutonium is particle reactive and deposited in marine sediment. Radioisotope {sup 239/240}Pu was determinated by alpha spectrometry after radiochemical procedure that was performed in both water and marine sediment from Bangka Island and Muria Peninsula. The sediment baseline of concentration {sup 239/240}Pu in Bangka Island and Muria Peninsula were range from 0.013 to 0.021 Bq.kg{sup ?1} and 0.018 to 0.024 Bq.kg{sup ?1} respectively. The water baseline concentration this isotope were range from 2.73 to 4.05 mBq.m{sup ?3} and 2.98 to 4.50 mBq.m{sup ?3}.

  17. Gamma-ray Output Spectra from 239 Pu Fission

    SciTech Connect (OSTI)

    Ullmann, John

    2015-05-25

    Gamma-ray multiplicities, individual gamma-ray energy spectra, and total gamma energy spectra following neutron-induced fission of 239Pu were measured using the DANCE detector at Los Alamos. Corrections for detector response were made using a forward-modeling technique based on propagating sets of gamma rays generated from a paramaterized model through a GEANT model of the DANCE array and adjusting the parameters for best fit to the measured spectra. The results for the gamma-ray spectrum and multiplicity are in general agreement with previous results, but the measured total gamma-ray energy is about 10% higher. A dependence of the gamma-ray spectrum on the gamma-ray multplicity was also observed. Global model calculations of the multiplicity and gamma energy distributions are in good agreement with the data, but predict a slightly softer total-energy distribution.

  18. DOE Plutonium Disposition Study: Pu consumption in ALWRs. Volume 1, Final report

    SciTech Connect (OSTI)

    Not Available

    1993-05-15

    The Department of Energy (DOE) has contracted with Asea Brown Boveri-Combustion Engineering (ABB-CE) to provide information on the capability of ABB-CE`s System 80 + Advanced Light Water Reactor (ALWR) to transform, through reactor burnup, 100 metric tonnes (MT) of weapons grade plutonium (Pu) into a form which is not readily useable in weapons. This information is being developed as part of DOE`s Plutonium Disposition Study, initiated by DOE in response to Congressional action. This document, Volume 1, presents a technical description of the various elements of the System 80 + Standard Plant Design upon which the Plutonium Disposition Study was based. The System 80 + Standard Design is fully developed and directly suited to meeting the mission objectives for plutonium disposal. The bass U0{sub 2} plant design is discussed here.

  19. Review of Calculations on Point Defect Properties in Delta-Pu

    SciTech Connect (OSTI)

    Allen, P. G.; Wolfer, W. G.

    2015-09-08

    The results of theoretical predictions of properties for vacancies and self-interstitial atoms (SIA) in δ-Pu are presented and reviewed. Three methods have been used for these predictions, namely the modified embedded atom method (MEAM), density functional theory (DFT) with and without spin polarization, and continuum mechanics (CM) models adapted to plutonium. The properties considered are formation and migration energies, and relaxation volumes of vacancies and SIA. Predicted values vary considerably. Nevertheless, all three methods predict that the activation energy for self-diffusion by vacancies is of similar magnitude as the SIA formation energy. Furthermore, the absolute magnitudes of relaxation volumes for vacancies and SIA are also similar, indicating that there exist no large bias for radiation-induced void swelling.

  20. An evaluation of alternate production methods for Pu-238 general purpose heat source pellets

    SciTech Connect (OSTI)

    Mark Borland; Steve Frank

    2009-06-01

    For the past half century, the National Aeronautics and Space Administration (NASA) has used Radioisotope Thermoelectric Generators (RTG) to power deep space satellites. Fabricating heat sources for RTGs, specifically General Purpose Heat Sources (GPHSs), has remained essentially unchanged since their development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the applicable fields of chemistry, manufacturing and control systems. This paper evaluates alternative processes that could be used to produce Pu 238 fueled heat sources. Specifically, this paper discusses the production of the plutonium-oxide granules, which are the input stream to the ceramic pressing and sintering processes. Alternate chemical processes are compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product.

  1. Microscopic modeling of mass and charge distributions in the spontaneous fission of 240Pu

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

    Sandhukhan, Jhilam; Nazarewicz, Witold; Schunck, Nicolas

    2016-01-20

    We propose a methodology to calculate microscopically the mass and charge distributions of spontaneous fission yields. We combine the multidimensional minimization of collective action for fission with stochastic Langevin dynamics to track the relevant fission paths from the ground-state configuration up to scission. The nuclear potential energy and collective inertia governing the tunneling motion are obtained with nuclear density functional theory in the collective space of shape deformations and pairing. As a result, we obtain a quantitative agreement with experimental data and find that both the charge and mass distributions in the spontaneous fission of 240Pu are sensitive both tomore » the dissipation in collective motion and to adiabatic fission characteristics.« less

  2. Hidden disorder in the α'→δ transformation of Pu-1.9 at.% Ga

    SciTech Connect (OSTI)

    Jeffries, J. R.; Manley, M. E.; Wall, M. A.; Blobaum, K. J. M.; Schwartz, A. J.

    2012-06-06

    Enthalpy and entropy are thermodynamic quantities critical to determining how and at what temperature a phase transition occurs. At a phase transition, the enthalpy and temperature-weighted entropy differences between two phases are equal (ΔH=TΔS), but there are materials where this balance has not been experimentally or theoretically realized, leading to the idea of hidden order and disorder. In a Pu-1.9 at. % Ga alloy, the δ phase is retained as a metastable state at room temperature, but at low temperatures, the δ phase yields to a mixed-phase microstructure of δ- and α'-Pu. The previously measured sources of entropy associated with the α'→δ transformation fail to sum to the entropy predicted theoretically. We report an experimental measurement of the entropy of the α'→δ transformation that corroborates the theoretical prediction, and implies that only about 65% of the entropy stabilizing the δ phase is accounted for, leaving a missing entropy of about 0.5 kB/atom. Some previously proposed mechanisms for generating entropy are discussed, but none seem capable of providing the necessary disorder to stabilize the δ phase. This hidden disorder represents multiple accessible states per atom within the δ phase of Pu that may not be included in our current understanding of the properties and phase stability of δ-Pu.

  3. The Precipitation of Sb2Te3 in Sb-rich AgSbTe2 via the Intermediate Phase

    Office of Scientific and Technical Information (OSTI)

    (AgSb)3Te4. (Journal Article) | SciTech Connect The Precipitation of Sb2Te3 in Sb-rich AgSbTe2 via the Intermediate Phase (AgSb)3Te4. Citation Details In-Document Search Title: The Precipitation of Sb2Te3 in Sb-rich AgSbTe2 via the Intermediate Phase (AgSb)3Te4. Abstract not provided. Authors: Sugar, Joshua Daniel ; Medlin, Douglas L. Publication Date: 2010-07-01 OSTI Identifier: 1124220 Report Number(s): SAND2010-5024J 492792 DOE Contract Number: DE-AC04-94AL85000 Resource Type: Journal

  4. New chalcogenide glasses in the CdTe-AgI-As{sub 2}Te{sub 3} system

    SciTech Connect (OSTI)

    Kassem, M.; Le Coq, D.; Boidin, R.; Bychkov, E.; ULCO, LPCA, EA 4493, F-59140 Dunkerque

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Determination of the glass-forming region in the pseudo-ternary CdTe-AgI-As{sub 2}Te{sub 3} system. Black-Right-Pointing-Pointer Characterization of macroscopic properties of the new CdTe-AgI-As{sub 2}Te{sub 3} glasses. Black-Right-Pointing-Pointer Characterization of the total conductivity of CdTe-AgI-As{sub 2}Te{sub 3} glasses. Black-Right-Pointing-Pointer Comparison between the selenide and telluride equivalent systems. -- Abstract: Chalcogenide glasses in the pseudo-ternary CdTe-AgI-As{sub 2}Te{sub 3} system were synthesized and the glass-forming range was determined. The maximum content of CdTe in this glass system was found to be equal to 15 mol.%. The macroscopic characterizations of samples have consisted in Differential Scanning Calorimetry, density, and X-ray diffraction measurements. The cadmium telluride addition does not generate any significant change in the glass transition temperature but the resistance of binary AgI-As{sub 2}Te{sub 3} glasses towards crystallisation is estimated to be decreasing on the base of {Delta}T = T{sub x} - T{sub g} parameter. The total electrical conductivity {sigma} was measured by complex impedance spectroscopy. First, the CdTe additions in the (AgI){sub 0.5}(As{sub 2}Te{sub 3}){sub 0.5} host glass, (CdTe){sub x}(AgI){sub 0.5-x/2}(As{sub 2}Te{sub 3}){sub 0.5-x/2} lead to a conductivity decrease at x {<=} 0.05. Then, the behaviour is reversed at 0.05 {<=} x {<=} 0.15. The obtained results are discussed by comparison with the equivalent selenide system.

  5. Burnup estimation of fuel sourcing radioactive material based on monitored Cs and Pu isotopic activity ratios in Fukushima N. P. S. accident

    SciTech Connect (OSTI)

    Yamamoto, T.; Suzuki, M.; Ando, Y.

    2012-07-01

    After the severe core damage of Fukushima Dai-Ichi Nuclear Power Station, radioactive material leaked from the reactor buildings. As part of monitoring of radioactivity in the site, measurements of radioactivity in soils at three fixed points have been performed for {sup 134}Cs and {sup 137}Cs with gamma-ray spectrometry and for Pu, Pu, and {sup 240}Pu with {alpha}-ray spectrometry. Correlations of radioactivity ratios of {sup 134}Cs to {sup 137}Cs, and {sup 238}Pu to the sum of {sup 239}Pu and {sup 240}Pu with fuel burnup were studied by using theoretical burnup calculations and measurements on isotopic inventories, and compared with the Cs and Pu radioactivity rations in the soils. The comparison indicated that the burnup of the fuel sourcing the radioactivity was from 18 to 38 GWd/t, which corresponded to that of the fuel in the highest power and, therefore, the highest decay heat in operating high-burnup fueled BWR cores. (authors)

  6. Estimation of 240Pu Mass in a Waste Tank Using Ultra-Sensitive Detection of Radioactive Xenon Isotopes from Spontaneous Fission

    SciTech Connect (OSTI)

    Bowyer, Ted W.; Gesh, Christopher J.; Haas, Derek A.; Hayes, James C.; Mahoney, Lenna A.; Meacham, Joseph E.; Mendoza, Donaldo P.; Olsen, Khris B.; Prinke, Amanda M.; Reid, Bruce D.; Woods, Vincent T.

    2014-12-01

    We report on a technique to detect and quantify the amount of 240Pu in a large tank used to store nuclear waste from plutonium production at the Hanford nuclear site. While the contents of this waste tank are known from previous grab sample measurements, our technique could allow for determination of the amount of 240Pu in the tank without costly sample retrieval and analysis of this highly radioactive material. This technique makes an assumption, which was confirmed, that 240Pu dominates the spontaneous fissions occurring in the tank.

  7. Stress and Diffusion in Stored Pu ZPPR Fuel from Alpha Generation

    SciTech Connect (OSTI)

    Charles W. Solbrig; Chad L. Pope; Jason P. Andrus

    2014-07-01

    ZPPR (Zero Power Physics Reactor) is a research reactor that has been used to investigate breeder reactor fuel designs. The reactor has been dismantled but its fuel is still stored there. Of concern are its plutonium containing metal fuel elements which are enclosed in stainless steel cladding with gas space filled with heliumargon gas and welded air tight. The fuel elements which are 5.08 cm by 0.508 cm up to 20.32 cm long (2 in 0.2 in 8 in) were manufactured in 1968. A few of these fuel elements have failed releasing contamination raising concern about the general state of the large number of other fuel elements. Inspection of the large number of fuel elements could lead to contamination release so analytical studies have been conducted to estimate the probability of failed fuel elements. This paper investigates the possible fuel failures due to generation of helium in the metal fuel from the decay of Pu and its possible damage to the fuel cladding from metal fuel expansion or from diffusion of helium into the fuel gas space. This paper (1) calculates the initial gas loading in a fuel element and its internal free volume after it has been brought into the atmosphere at ZPPR, (2) shows that the amount of helium generated by decay of Pu over 46 years since manufacture is significantly greater than this initial loading, (3) determines the amount of fuel swelling if the helium stays fixed in the fuel plate and estimates the amount of helium which diffuses out of the fuel plate into the fuel plenum assuming the helium does not remain fixed in the fuel plate but can diffuse to the plenum and possibly through the cladding. Since the literature is not clear as to which possibility occurs, as with Schroedingers cat, both possibilities are analyzed. The paper concludes that (1) if the gas generated is fixed in the fuel, then the fuel swelling it can cause would not cause any fuel failure and (2) if the helium does diffuse out of the fuel (in accordance diffusivities estimated from the literature), then it is unlikely that fuel element bulging will occur.

  8. Rational Ligand Design for U(VI) and Pu(IV)

    SciTech Connect (OSTI)

    Szigethy, Geza

    2009-08-12

    Nuclear power is an attractive alternative to hydrocarbon-based energy production at a time when moving away from carbon-producing processes is widely accepted as a significant developmental need. Hence, the radioactive actinide power sources for this industry are necessarily becoming more widespread, which is accompanied by the increased risk of exposure to both biological and environmental systems. This, in turn, requires the development of technology designed to remove such radioactive threats efficiently and selectively from contaminated material, whether that be contained nuclear waste streams or the human body. Raymond and coworkers (University of California, Berkeley) have for decades investigated the interaction of biologically-inspired, hard Lewis-base ligands with high-valent, early-actinide cations. It has been established that such ligands bind strongly to the hard Lewis-acidic early actinides, and many poly-bidentate ligands have been developed and shown to be effective chelators of actinide contaminants in vivo. Work reported herein explores the effect of ligand geometry on the linear U(IV) dioxo dication (uranyl, UO{sub 2}{sup 2+}). The goal is to utilize rational ligand design to develop ligands that exhibit shape selectivity towards linear dioxo cations and provides thermodynamically favorable binding interactions. The uranyl complexes with a series of tetradentate 3-hydroxy-pyridin-2-one (3,2-HOPO) ligands were studied in both the crystalline state as well as in solution. Despite significant geometric differences, the uranyl affinities of these ligands vary only slightly but are better than DTPA, the only FDA-approved chelation therapy for actinide contamination. The terepthalamide (TAM) moiety was combined into tris-beidentate ligands with 1,2- and 3,2-HOPO moieties were combined into hexadentate ligands whose structural preferences and solution thermodynamics were measured with the uranyl cation. In addition to achieving coordinative saturation, these ligands exhibited increased uranyl affinity compared to bis-Me-3,2-HOPO ligands. This result is due in part to their increased denticity, but is primarily the result of the presence of the TAM moiety. In an effort to explore the relatively unexplored coordination chemistry of Pu(IV) with bidentate moieties, a series of Pu(IV) complexes were also crystallized using bidentate hydroxypyridinone and hydroxypyrone ligands. The geometries of these complexes are compared to that of the analogous Ce(IV) complexes. While in some cases these showed the expected structural similarities, some ligand systems led to significant coordination changes. A series of crystal structure analyses with Ce(IV) indicated that these differences are most likely the result of crystallization condition differences and solvent inclusion effects.

  9. Luminosity goals for a 100-TeV pp collider

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

    Hinchliffe, Ian; Kotwal, Ashutosh; Mangano, Michelangelo L.; Quigg, Chris; Wang, Lian-Tao

    2015-08-20

    We consider diverse examples of science goals that provide a framework to assess luminosity goals for a future 100-TeV proton-proton collider.

  10. Battle Mountain Band - Te-Moak: Solar Energy Park

    Office of Environmental Management (EM)

    Battle Mountain Band - Te-Moak Chairman Joseph Holley and Vice-chairman Mark Oppenhein, Members Donna Hill, Delbert Holley, Lydia Johnson, and Lydell Oppenhein Solar Energy Park ...

  11. Luminosity goals for a 100-TeV pp collider

    SciTech Connect (OSTI)

    Hinchliffe, Ian; Kotwal, Ashutosh; Mangano, Michelangelo L.; Quigg, Chris; Wang, Lian-Tao

    2015-04-23

    We consider diverse examples of science goals that provide a framework to assess luminosity goals for a future 100-TeV proton-proton collider.

  12. Evaluation of Aqueous and Powder Processing Techniques for Production of Pu-238-Fueled General Purpose Heat Sources

    SciTech Connect (OSTI)

    Not Available

    2008-06-01

    This report evaluates alternative processes that could be used to produce Pu-238 fueled General Purpose Heat Sources (GPHS) for radioisotope thermoelectric generators (RTG). Fabricating GPHSs with the current process has remained essentially unchanged since its development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the fields of chemistry, manufacturing, ceramics, and control systems. At the Department of Energy’s request, alternate manufacturing methods were compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product. An expert committee performed the evaluation with input from four national laboratories experienced in Pu-238 handling.

  13. Rapid fusion method for the determination of Pu, Np, and Am in large soil samples

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

    Maxwell, Sherrod L.; Culligan, Brian; Hutchison, Jay B.; McAlister, Daniel R.

    2015-02-14

    A new rapid sodium hydroxide fusion method for the preparation of 10-20 g soil samples has been developed by the Savannah River National Laboratory (SRNL). The method enables lower detection limits for plutonium, neptunium, and americium in environmental soil samples. The method also significantly reduces sample processing time and acid fume generation compared to traditional soil digestion techniques using hydrofluoric acid. Ten gram soil aliquots can be ashed and fused using the new method in 1-2 hours, completely dissolving samples, including refractory particles. Pu, Np and Am are separated using stacked 2mL cartridges of TEVA and DGA Resin and measuredmore » using alpha spectrometry. The method can be adapted for measurement by inductively-coupled plasma mass spectrometry (ICP-MS). Two 10 g soil aliquots of fused soil may be combined prior to chromatographic separations to further improve detection limits. Total sample preparation time, including chromatographic separations and alpha spectrometry source preparation, is less than 8 hours.« less

  14. Copper migration in CdTe heterojunction solar cells

    SciTech Connect (OSTI)

    Chou, H.C.; Rohatgi, A.; Jokerst, N.M.; Thomas, E.W.; Kamra, S.

    1996-07-01

    CdTe solar cells were fabricated by depositing a Au/Cu contact with Cu thickness in the range of 50 to 150A on polycrystalline CdTe/CdS/SnO{sub 2} glass structures. The increase in Cu thickness improves ohmic contact and reduces series resistance (R{sub s}), but the excess Cu tends to diffuse into CdTe and lower shunt resistance (R{sub sh}) and cell performance. Light I-V and secondary ion mass spectroscopy (SIMS) measurements were performed to understand the correlations between the Cu contact thickness, the extent of Cu incorporation in the CdTe cells, and its impact on the cell performance. The CdTe/CdS/SnO{sub 2} glass, CdTe/CdS/GaAs, and CdTe/GaAs structures were prepared in an attempt to achieve CdTe films with different degrees of crystallinity and grain size. A large grain polycrystalline CdTe thin film solar cell was obtained for the first time by selective etching the GaAs substrate coupled with the film transfer onto a glass substrate. SIMS measurement showed that poor crystallinity and smaller grain size of the CdTe film promotes Cu diffusion and decreases the cell performance. Therefore, grain boundaries are the main conduits for Cu migration and larger CdTe grain size or alternate method of contact formation can mitigate the adverse effect of Cu and improve the cell performance. 15 refs., 1 fig.,6 tabs.

  15. Assessment of a mechanistic model in U-Pu-Zr metallic alloy fuel fission-gas behavior simulations

    SciTech Connect (OSTI)

    Yun, D.; Rest, J.; Yacout, A. M.

    2012-07-01

    A mechanistic kinetic rate theory model originally developed for the prediction of fission gas behavior in oxide nuclear fuels under steady-state and transient conditions has been assessed to look at its applicability to model fission gas behavior in U-Pu-Zr metallic alloy fuel. In order to capture and validate the underlying physics for irradiated U-Pu-Zr fuels, the mechanistic model was applied to the simulation of fission gas release, fission gas and fission product induced swelling, and the evolution of the gas bubble size distribution in three different fuel zones: the outer {alpha}-U, the intermediate, and the inner {gamma}-U zones. Due to its special microstructural features, the {alpha}-U zone in U-Pu-Zr fuels is believed to contribute the largest fraction of fission gas release among the different fuel zones. It is shown that with the use of small effective grain sizes, the mechanistic model can predict fission gas release that is consistent with (though slightly lower than) experimentally measured data. These simulation results are comparable to the experimentally measured fission gas release since the mechanism of fission gas transport through the densely distributed laminar porosity in the {alpha}-U zone is analogous to the mechanism of fission gas transport through the interconnected gas bubble porosity utilized in the mechanistic model. Detailed gas bubble size distributions predicted with the mechanistic model in both the intermediate zone and the high temperature {gamma}-U zone of U-Pu-Zr fuel are also compared to experimental measurements from available SEM micrographs. These comparisons show good agreements between the simulation results and experimental measurements, and therefore provide crucial guidelines for the selection of key physical parameters required for modeling these two zones. In addition, the results of parametric studies for several key parameters are presented for both the intermediate zone and the {gamma}-U zone simulations. (authors)

  16. Modeling of selected ceramic processing parameters employed in the fabrication of 238PuO2 fuel pellets

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

    Brockman, R. A.; Kramer, D. P.; Barklay, C. D.; Cairns-Gallimore, D.; Brown, J. L.; Huling, J. C.; Van Pelt, C. E.

    2011-10-01

    Recent deep space missions utilize the thermal output of the radioisotope plutonium-238 as the fuel in the thermal to electrical power system. Since the application of plutonium in its elemental state has several disadvantages, the fuel employed in these deep space power systems is typically in the oxide form such as plutonium-238 dioxide (238PuO2). As an oxide, the processing of the plutonium dioxide into fuel pellets is performed via ''classical'' ceramic processing unit operations such as sieving of the powder, pressing, sintering, etc. Modeling of these unit operations can be beneficial in the understanding and control of processing parameters withmore » the goal of further enhancing the desired characteristics of the 238PuO2 fuel pellets. A finite element model has been used to help identify the time-temperature-stress profile within a pellet during a furnace operation taking into account that 238PuO2 itself has a significant thermal output. The results of the modeling efforts will be discussed.« less

  17. Effect of 1-hydroxyethane-1,1-diphosphonic acid (HEDPA) on Partitioning of Np and Pu to Synthetic Boehmite

    SciTech Connect (OSTI)

    Powell, Brian A.; Rao, Linfeng; Nash, Kenneth L.

    2009-05-01

    The effect of 1-hydroxyethane-1,1-diphosphonic acid (HEDPA) on sorption of Np(V) and Pu(V) to synthetic boehmite ({gamma}-AlOOH) was examined a function of time and pH (between 4 to 11). Sorption of both elements in boehmite suspensions (1 M NaCl, 600 mg L{sup -1} boehmite) increased with increasing pH. Sorption edges for neptunium and plutonium occurred at approximately pH 8.0 and 6.6, respectively. After steady state partitioning was reached, HEDPA was added to the neptunium-boehmite and plutonium-boehmite suspensions. Neptunium and plutonium partitioning appears to be primarily affected by the formation of soluble Np:HEDPA and Pu:HEDPA complexes, the dissolution of boehmite promoted by HEDPA, and the precipitation of Np:HEDPA and Pu:HEDPA colloids. The results are discussed in terms of applicability of HEDPA-promoted dissolution as a waste reduction method in the treatment of sludge phases contained within high-level nuclear waste storage tanks.

  18. Use of separate ZnTe interface layers to form OHMIC contacts to p-CdTe films

    DOE Patents [OSTI]

    Gessert, Timothy A. (Conifer, CO)

    1999-01-01

    A method of improving electrical contact to a thin film of a p-type tellurium-containing II-VI semiconductor comprising: depositing a first undoped layer of ZnTe on a thin film of p-type tellurium containing II-VI semiconductor with material properties selected to limit the formation of potential barriers at the interface between the p-CdTe and the undoped layer, to a thickness sufficient to control diffusion of the metallic-doped ZnTe into the p-type tellurim-containing II-VI semiconductor, but thin enough to minimize affects of series resistance; depositing a second heavy doped p-type ZnTe layer to the first layer using an appropriate dopant; and depositing an appropriate metal onto the outer-most surface of the doped ZnTe layer for connecting an external electrical conductor to an ohmic contact.

  19. Use of separate ZnTe interface layers to form ohmic contacts to p-CdTe films

    DOE Patents [OSTI]

    Gessert, T.A.

    1999-06-01

    A method of is disclosed improving electrical contact to a thin film of a p-type tellurium-containing II-VI semiconductor comprising: depositing a first undoped layer of ZnTe on a thin film of p-type tellurium containing II-VI semiconductor with material properties selected to limit the formation of potential barriers at the interface between the p-CdTe and the undoped layer, to a thickness sufficient to control diffusion of the metallic-doped ZnTe into the p-type tellurium-containing II-VI semiconductor, but thin enough to minimize affects of series resistance; depositing a second heavy doped p-type ZnTe layer to the first layer using an appropriate dopant; and depositing an appropriate metal onto the outer-most surface of the doped ZnTe layer for connecting an external electrical conductor to an ohmic contact. 11 figs.

  20. Multiband Te p Based Superconductivity of Ta4Pd3Te16

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

    Singh, David J.

    2014-10-06

    We recently discovered that Ta4Pd3Te16 is a superconductor that has been suggested to be an unconventional superconductor near magnetism. Here, we report electronic structure calculations showing that despite the layered crystal structure the material is an anisotropic three-dimensional (3D) metal. The Fermi surface contains prominent one-dimensional (1D) and two-dimensional (2D) features, including nested 1D sheets, a 2D cylindrical section, and a 3D sheet. Moreover, the electronic states that make up the Fermi surface are mostly derived from Te p states with small Ta d and Pd d contributions. This places the compound far from magnetic instabilities. The results are discussedmore » in terms of multiband superconductivity.« less

  1. Electrochemically deposited BiTe-based nanowires for thermoelectric applications

    SciTech Connect (OSTI)

    Ng, Inn-Khuan; Kok, Kuan-Ying; Rahman, Che Zuraini Che Ab; Saidin, Nur Ubaidah; Ilias, Suhaila Hani; Choo, Thye-Foo

    2014-02-12

    Nanostructured materials systems such as thin-films and nanowires (NWs) are promising for thermoelectric power generation and refrigeration compared to traditional counterparts in bulk, due to their enhanced thermoelectric figures-of-merit. BiTe and its derivative compounds, in particular, are well-known for their near-room temperature thermoelectric performance. In this work, both the binary and ternary BiTe-based nanowires namely, BiTe and BiSbTe, were synthesized using template-assisted electrodeposition. Diameters of the nanowires were controlled by the pore sizes of the anodised alumina (AAO) templates used. Systematic study on the compositional change as a function of applied potential was carried out via Linear Sweep Voltanmetry (LSV). Chemical compositions of the nanowires were studied using Energy Dispersive X-ray Spectrometry (EDXS) and their microstructures evaluated using diffraction and imaging techniques. Results from chemical analysis on the nanowires indicated that while the Sb content in BiSbTe nanowires increased with more negative deposition potentials, the formation of Te{sup 0} and Bi{sub 2}Te{sub 3} were favorable at more positive potentials.

  2. Process Development for High Voc CdTe Solar Cells

    SciTech Connect (OSTI)

    Ferekides, C. S.; Morel, D. L.

    2011-05-01

    This is a cumulative and final report for Phases I, II and III of this NREL funded project (subcontract # XXL-5-44205-10). The main research activities of this project focused on the open-circuit voltage of the CdTe thin film solar cells. Although, thin film CdTe continues to be one of the leading materials for large-scale cost-effective production of photovoltaics, the efficiency of the CdTe solar cells have been stagnant for the last few years. This report describes and summarizes the results for this 3-year research project.

  3. TRISO-Fuel Element Performance Modeling for the Hybrid LIFE Engine with Pu Fuel Blanket

    SciTech Connect (OSTI)

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

    2010-02-18

    A TRISO-coated fuel thermo-mechanical performance study is performed for the hybrid LIFE engine to test the viability of TRISO particles to achieve ultra-high burnup of a weapons-grade Pu blanket. Our methodology includes full elastic anisotropy, time and temperature varying material properties for all TRISO layers, and a procedure to remap the elastic solutions in order to achieve fast fluences up to 30 x 10{sup 25} n {center_dot} m{sup -2} (E > 0.18 MeV). In order to model fast fluences in the range of {approx} 7 {approx} 30 x 10{sup 25} n {center_dot} m{sup -2}, for which no data exist, careful scalings and extrapolations of the known TRISO material properties are carried out under a number of potential scenarios. A number of findings can be extracted from our study. First, failure of the internal pyrolytic carbon (PyC) layer occurs within the first two months of operation. Then, the particles behave as BISO-coated particles, with the internal pressure being withstood directly by the SiC layer. Later, after 1.6 years, the remaining PyC crumbles due to void swelling and the fuel particle becomes a single-SiC-layer particle. Unrestrained by the PyC layers, and at the temperatures and fluences in the LIFE engine, the SiC layer maintains reasonably-low tensile stresses until the end-of-life. Second, the PyC creep constant, K, has a striking influence on the fuel performance of TRISO-coated particles, whose stresses scale almost inversely proportional to K. Obtaining more reliable measurements, especially at higher fluences, is an imperative for the fidelity of our models. Finally, varying the geometry of the TRISO-coated fuel particles results in little differences in the scope of fuel performance. The mechanical integrity of 2-cm graphite pebbles that act as fuel matrix has also been studied and it is concluded that they can reliable serve the entire LIFE burnup cycle without failure.

  4. Comparison of {sup 241}Am, {sup 239,240}Pu, and {sup 137}Cs concentrations in soil around Rocky Flats

    SciTech Connect (OSTI)

    Hulse, S.E.; Ibrahim, S.A.; Whicker, F.W.; Chapman, P.L.

    1999-03-01

    Gamma spectroscopy measurements were used to estimate concentrations of {sup 241}Am and {sup 137}Cs in soil profiles to depths of 21 cm at on-site and off-site locations around the Rocky Flats Environmental Technology Site and at regional background locations east of the Front Range between Colorado`s borders with New Mexico and Wyoming. Concentrations of these radionuclides were compared with concentrations of {sup 239,240}Pu in the same samples. Concentrations of {sup 241}Am in soil from depths of 0 to 3 cm decreased in an easterly direction from more than 5.3 kBq kg{sup {minus}1} 5 to 7 km away at a rate that was nearly proportional to the inverse square of distance. Deposits of {sup 137}Cs were ubiquitous, averaging 0.12 kBq kg{sup {minus}1} in soil from depths of 0 to 3 cm, but were unevenly distributed around Rocky Flats and the regional background locations. Deviations from the uniform exponential rate at which soil concentrations of {sup 137}Cs typically decreased with depth, {minus}0.25 cm{sup {minus}1} at undisturbed sites, enabled the authors to determine that about 10% of their sampling sites had been disturbed by erosion, tillage, or other factors. The mean rate at which {sup 239,240}Pu decreased with depth was about the same, {minus}0.23 cm{sup {minus}1}, throughout the study area. Soil concentrations of {sup 241}Am decreased with depth at a similar mean rate of {minus}0.22 cm{sup {minus}1} at locations close to the 903 pad where measurements were robust. Ratios between {sup 241}Am or {sup 239,240}Pu and {sup 137}Cs proved more useful for delineating the extent and pattern of contamination from Rocky Flats than did activity concentrations in soil.

  5. Full-length U-xPu-10Zr (x=0, 8, 19 wt%) Fast Reactor Fuel Test in FFTF

    SciTech Connect (OSTI)

    D. L. Porter; H.C. Tsai

    2012-08-01

    The Integral Fast Reactor-1 (IFR-1) experiment performed in the Fast Flux Test Facility (FFTF) was the only U-Pu-10Zr (Pu-0, 8 and 19 wt%) metallic fast reactor test with commercial-length (91.4 cm active fuel column length) conducted to date. With few remaining test reactors there is little opportunity for performing another test with a long active fuel column. The assembly was irradiated to the goal burnup of 10 at.%. The beginning of life (BOL) peak cladding temperature of the hottest pin was 608?C, cooling to 522?C at end of life (EOL). Selected fuel pins were examined non destructively using neutron radiography, precision axial gamma scanning, and both laser and spiral contact cladding profilometry. Destructive exams included plenum gas pressure, volume, and gas composition determinations on a number of pins followed by optical metallography, electron probe microanalysis (EPMA), and alpha and beta gamma autoradiography on a single U-19Pu-10Zr pin. The post-irradiation examinations (PIEs) showed very few differences compared to the short-pin (34.3 cm fuel column) testing performed on fuels of similar composition in Experimental Breeder Reactor-II (EBR-II). The fuel column grew axially slightly less than observed in the short pins, but with the same pattern of decreasing growth with increasing Pu content. There was a difference in the fuel-cladding chemical interaction (FCCI) in that the maximum cladding penetration by interdiffusion with fuel/fission products did not occur at the top of the fuel column where the cladding temperature is highest, as observed in EBR-II tests. Instead, the more exaggerated fission-rate profile of the FFTF pins resulted in a peak FCCI at ~0.7 X/L axial location along the fuel column. This resulted from a lower production of rare earth fission products higher in the fuel column as well as a much smaller delta-T between fuel center and cladding, and therefore less FCCI, despite the higher cladding temperature. This behavior could actually help extend the life of a fuel pin in a long pin reactor design to a higher peak fuel burnup.

  6. Magneto-optical characterizations of FeTe???Se??? thin...

    Office of Scientific and Technical Information (OSTI)

    distributed in the two thin films. Compared with bulk crystals, FeTeSe thin film demonstrates not only higher Tc, but also much larger Jc, which is attractive...

  7. Native defects in MBE-grown CdTe

    SciTech Connect (OSTI)

    Olender, Karolina; Wosinski, Tadeusz; Makosa, Andrzej; Tkaczyk, Zbigniew; Kolkovsky, Valery; Karczewski, Grzegorz

    2013-12-04

    Deep-level traps in both n- and p-type CdTe layers, grown by molecular-beam epitaxy on GaAs substrates, have been investigated by means of deep-level transient spectroscopy (DLTS). Four of the traps revealed in the DLTS spectra, which displayed exponential kinetics for capture of charge carriers into the trap states, have been assigned to native point defects: Cd interstitial, Cd vacancy, Te antisite defect and a complex formed of the Te antisite and Cd vacancy. Three further traps, displaying logarithmic capture kinetics, have been ascribed to electron states of treading dislocations generated at the mismatched interface with the substrate and propagated through the CdTe layer.

  8. PVA TePla AG | Open Energy Information

    Open Energy Info (EERE)

    search Name: PVA TePla AG Place: Asslar, Germany Zip: 35614 Product: Supplier of plants and equipment for vacuum systems, crystal-growing systems and plasma systems, some of...

  9. Summary of the TeV33 working group

    SciTech Connect (OSTI)

    Bagley, P.P.; Bieniosek, F.M.; Colestock, P.

    1996-10-01

    This summary of the TeV33 working group at Snowmass reports on work in the areas of Tevatron store parameters, the beam-beam interaction, Main Injector intensity (slip stacking), antiproton production, and electron cooling.

  10. Extreme solid state refrigeration using nanostructured Bi-Te alloys.

    SciTech Connect (OSTI)

    Lima Sharma, Ana L.; Spataru, Dan Catalin; Medlin, Douglas L.; Sharma, Peter Anand; Morales, Alfredo Martin

    2009-09-01

    Materials are desperately needed for cryogenic solid state refrigeration. We have investigated nanostructured Bi-Te alloys for their potential use in Ettingshausen refrigeration to liquid nitrogen temperatures. These alloys form alternating layers of Bi{sub 2} and Bi{sub 2}Te{sub 3} blocks in equilibrium. The composition Bi{sub 4}Te{sub 3} was identified as having the greatest potential for having a high Ettingshausen figure of merit. Both single crystal and polycrystalline forms of this material were synthesized. After evaluating the Ettingshausen figure of merit for a large, high quality polycrystal, we simulated the limits of practical refrigeration in this material from 200 to 77 K using a simple device model. The band structure was also computed and compared to experiments. We discuss the crystal growth, transport physics, and practical refrigeration potential of Bi-Te alloys.

  11. Phonon self-energy and origin of anomalous neutron scattering spectra in SnTe and PbTe thermoelectrics

    SciTech Connect (OSTI)

    Li, Chen [ORNL] [ORNL; Ma, Jie [ORNL] [ORNL; May, Andrew F [ORNL] [ORNL; Cao, Huibo [ORNL] [ORNL; Christianson, Andrew D [ORNL] [ORNL; Ehlers, Georg [ORNL] [ORNL; Singh, David J [ORNL] [ORNL; Sales, Brian C [ORNL] [ORNL; Delaire, Olivier A [ORNL] [ORNL

    2014-01-01

    The anharmonic lattice dynamics of rock-salt thermoelectric compounds SnTe and PbTe are investigated with inelastic neutron scattering (INS) and first-principles calculations. The experiments show that, surprisingly, although SnTe is closer to the ferroelectric instability, phonon spectra in PbTe exhibit a more anharmonic character. This behavior is reproduced in first-principles calculations of the temperature-dependent phonon self-energy. Our simulations reveal how the nesting of phonon dispersions induces prominent features in the self-energy, which account for the measured INS spectra and their temperature dependence. We establish that the phase-space for three-phonon scattering processes, rather than just the proximity to the lattice instability, is the mechanism determining the complex spectrum of the transverse-optical ferroelectric mode.

  12. Effects of Aging on PuO2?xH2O Particle Size in Alkaline Solution

    SciTech Connect (OSTI)

    Delegard, Calvin H.

    2013-05-01

    Between 1944 and 1989, 54.5 metric tons of the United States weapons-grade plutonium and an additional 12.9 metric tons of fuel-grade plutonium were produced and separated from irradiated fuel at the Hanford Site. Acidic high-activity wastes containing around 600 kg of plutonium were made alkaline and discharged to underground storage tanks from separations, isolation, and recycle processes to yield average plutonium concentration of about 0.003 grams per liter (or ~0.0002 wt%) in the ~200 million liter tank waste volume. The plutonium is largely associated with low-solubility metal hydroxide/oxide sludges where its low concentration and intimate mixture with neutron-absorbing elements (e.g., iron) are credited in nuclear criticality safety. However, concerns have been expressed that plutonium, in the form of plutonium hydrous oxide, PuO2?xH2O, could undergo sufficient crystal growth through dissolution and reprecipitation in the alkaline tank waste to potentially become separable from neutron absorbing constituents by settling or sedimentation. Thermodynamic considerations and laboratory studies of systems chemically analogous to tank waste show that the plutonium formed in the alkaline tank waste by precipitation through neutralization from acid solution probably entered as 24-nm PuO2?xH2O crystallite particles that, because of their low solubility and opposition from radiolytic processes, grow from that point at exceedingly slow rates, thus posing no risk of physical segregation.

  13. Isothermal Martensitic and Pressure-Induced Delta to Alpha-Prime Phase Transformations in a Pu-Ga Alloy

    SciTech Connect (OSTI)

    Schwartz, A J; Wall, M A; Farber, D L; Moore, K T; Blobaum, K M

    2008-01-18

    A well-homogenized Pu-2 at.% Ga alloy can be retained in the metastable face-centered cubic {delta} phase at room temperature. Ultimately, this metastable {delta} phase will decompose via a eutectoid transformation to the thermodynamically stable monoclinic {alpha} phase and the intermetallic compound Pu{sub 3}Ga over a period of approximately 10,000 years [1]. In addition, these low solute-containing {delta}-phase Pu alloys are metastable with respect to an isothermal martensitic phase transformation to the {alpha}{prime} phase during low temperature excursions [2, 3] and are also metastable with respect to a {delta} {yields} {alpha}{prime} phase transformation with increases in pressure [3-5]. The low temperature {delta} {yields} {alpha}{prime} isothermal martensitic phase transformation in the Pu-2 at.% Ga alloy only goes to {approx}25% completion with the resultant {approx}20 {micro}m long by 2 {micro}m wide lath-shaped {alpha}{prime} particles dispersed within the {delta} matrix. In recently reported studies, Faure et al. [4] have observed a {delta} {yields} {gamma} {yields} {alpha}{prime} pressure-induced phase transformation sequence during a diamond anvil cell investigation and, based on x-ray diffraction and density and compressibility experiments, Harbur [5] has concluded that both {alpha}{prime} and an amorphous phase are present in samples that were pressurized and recovered. In this work, a large volume moissanite anvil cell is constructed to permit the pressurization and recovery of specimens of a size suitable for TEM and electron diffraction studies. The cell, shown in Fig. 1, has an overall diameter of 101.6 mm, a moissanite anvil diameter of 9.00 mm, a culet size of 3 mm, and a spring steel gasket 0.5 mm thick with a hole diameter of 2.5 mm. A 2.3 mm diameter by 100 {micro}m thick sample of {delta}-phase Pu-2 at.% Ga is compressed at a rate of approximately 0.05 GPa/minute to {approx}1 GPa to induce the phase transformation to {alpha}{prime}. Optical microscopy of the recovered specimen reveals a very fine microstructure that appears to be single phase, although the resolution of this technique is insufficient to differentiate between single and multiple phases if the grain size is below approximately 1 {micro}m. X-ray diffraction, using a laboratory Cu K{sub {alpha}} source with wavelength of 1.542{angstrom}, shows the monoclinic reflections from the {alpha}{prime} phase, strong peaks from the aluminum specimen holder, and weak peaks from the face-centered cubic {delta} phase as shown in Fig. 2. The recovered specimen is prepared for TEM and electron diffraction studies as described in Moore et al. [6]. TEM reveals small regions of {delta} phase with a very high dislocation density interspersed between the 10-100's nm {alpha}{prime} grains as shown in Fig. 3. Electron diffraction, shown in the insert in Fig. 3, clearly reveals the presence of the {delta} phase. This microstructure is in contrast to the {alpha}{prime} particles that form as a result of the low-temperature isothermal martensite in which the {alpha}{prime} particles are lath-shaped and significantly larger as shown in the optical micrograph in Fig. 4 of a sample cooled to -120 C and held for 10 hours. In these preliminary results, there is no evidence of either an amorphous phase, as suggested by Harbur [5], or the presence of a {gamma} phase. We expected to observe an amorphous phase based on the similarity of this experiment to that of Harbur [5]. It is possible that the {gamma} phase, as reported by Faure et al. [4], does form as an intermediate, but it is not retained to ambient pressure.

  14. Analysis of Pu-Only Partitioning Strategies in LMFBR Fuel Cycles

    SciTech Connect (OSTI)

    Samuel Bays; Gilles Youinou

    2013-02-01

    Sodium cooled Fast Reactors (SFR) have been under consideration for production of electricity, fissile material production, and for destruction of transuranics for decades. The neutron economy of a SFR can be operated in one of two ways. One possibility is to operate the reactor in a transuranic burner mode which has been the focus of active R&D in the last 15 years. However, prior to that the focus was on breeding transuranics. This later mode of managing the neutron economy relies on ensuring the maximum fuel utilization possible in such a way as to maximize the amount of plutonium produced per unit of fission energy in the reactor core. The goal of maximizing plutonium production in this study is as fissile feed stock for the production of MOX fuel to be used in Light Water Reactors (LWR). Throughout the l970s, this fuel cycle scenario was the focus of much research by the Atomic Energy Commission in the event that uranium supplies would be scarce. To date, there has been sufficient uranium to supply the once through nuclear fuel cycle. However, interest in a synergistic relationship Liquid Metal Fast Breeder Reactors (LMFBR) and a consumer LWR fleet persists, prompting this study. This study considered LMFBR concepts with varying additions of axial and radial reflectors. Three scenarios were considered in collaboration with a companion study on the LWR-MOX designs based on plutonium nuclide vectors produced by this study. The first scenario is a LMFBR providing fissile material to make MOX fuel where the MOX part of the fuel cycle is operated in a once-through-then-out mode. The second scenario is the same as the first but with the MOX part of the fuel cycle multi-recycling its own plutonium with LMFBR being used for the make-up feed. In these first two scenarios, plutonium partitioning from the minor actinides (MA) was assumed. Also, the plutonium management strategy of the LMFBR ensured that only the high fissile purity plutonium bred from blankets was sold to the MOX LWRs. The third scenario considered a LMFBR fuel cycle in an expansionary mode where excess bred transuranic material is accumulated for spinning off additional LMFBR cores. In this latter scenario, no plutonium partitioning was considered. After every cycle, transuranic from both driver and blankets is sold to the MOX LWRs. The MA production from LMFBR operated in a Pu-only fuel cycle is roughly only 1% that of the transuranic production rate. This is in contrast to LWR fuel cycles where the MA content in TRU is closer to 10% or more. If such a LMFBR were operated to provide fissile material to a fleet of MOX reactors, then 1 GWe of LMFBR could support between approximately 0.11 and 0.43 GWe of LWR-MOX reactors for a LMFBR conversion ratio between 1.1 and 1.5, if the MOX reactors were operated in a once-through-then out mode. If the plutonium is continuously recycled in the MOX reactors then the support ratio is approximately 1 GWe of LMFBR for between 0.13 and 0.65 GWe of LWR-MOX reactors depending on the LMFBR conversion ratio. Also, it was found that if the LMFBR fleet were operated in a purely expansionary mode, the smallest doubling time achievable would be seven years.

  15. 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.

  16. The half-life of {sup 131g,m}Te

    SciTech Connect (OSTI)

    Ruivo, J. C.; Zamboni, C. B.; Oliveira, J. R. B.; Heder Medina, Nilberto

    2013-05-06

    In this work, the half-lives of {sup 131m}Te and {sup 131g}Te were measured. Radioactive sources of {sup 131}Te were obtained using the {sup 130}Te(n,{gamma}){sup 131}Te nuclear reaction. These nuclear parameters have been determined with a better confidence and accuracy than previously available: 18.89 {+-} 0.11 min and 33.18 {+-} 0.13 h, respectively. These results are quite helpful for new calculations that attempt to describe the low-lying levels in {sup 131}I from the decay of {sup 131g,m}Te.

  17. Heterojunctions of model CdTe/CdSe mixtures

    SciTech Connect (OSTI)

    van Swol, Frank; Zhou, Xiaowang W.; Challa, Sivakumar R.; Martin, James E.

    2015-03-18

    We report on the strain behavior of compound mixtures of model group IIVI semiconductors. We use the StillingerWeber Hamiltonian that we recently introduced, specifically developed to model binary mixtures of group IIVI compounds such as CdTe and CdSe. We also employ molecular dynamics simulations to examine the behavior of thin sheets of material, bilayers of CdTe and CdSe. The lattice mismatch between the two compounds leads to a strong bending of the entire sheet, with about a 0.5 to 1 deflection between neighboring planes. To further analyze bilayer bending, we introduce a simple one-dimensional model and use energy minimization to find the angle of deflection. The analysis is equivalent to a least-squares straight line fit. We consider the effects of bilayers which are asymmetric with respect to the thickness of the CdTe and CdSe parts. We thus learn that the bending can be subdivided into four kinds depending on the compressive/tensile nature of each outer plane of the sheet. We use this approach to directly compare our findings with experimental results on the bending of CdTe/CdSe rods. To reduce the effects of the lattice mismatch we explore diffuse interfaces, where we mix (i.e. alloy) Te and Se, and estimate the strain response.

  18. Heterojunctions of model CdTe/CdSe mixtures

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

    van Swol, Frank; Zhou, Xiaowang W.; Challa, Sivakumar R.; Martin, James E.

    2015-03-18

    We report on the strain behavior of compound mixtures of model group II-VI semiconductors. We use the Stillinger-Weber Hamiltonian that we recently introduced, specifically developed to model binary mixtures of group II-VI compounds such as CdTe and CdSe. We also employ molecular dynamics simulations to examine the behavior of thin sheets of material, bilayers of CdTe and CdSe. The lattice mismatch between the two compounds leads to a strong bending of the entire sheet, with about a 0.5 to 1° deflection between neighboring planes. To further analyze bilayer bending, we introduce a simple one-dimensional model and use energy minimization tomore » find the angle of deflection. The analysis is equivalent to a least-squares straight line fit. We consider the effects of bilayers which are asymmetric with respect to the thickness of the CdTe and CdSe parts. We thus learn that the bending can be subdivided into four kinds depending on the compressive/tensile nature of each outer plane of the sheet. We use this approach to directly compare our findings with experimental results on the bending of CdTe/CdSe rods. To reduce the effects of the lattice mismatch we explore diffuse interfaces, where we mix (i.e. alloy) Te and Se, and estimate the strain response.« less

  19. Growth, steady-state, and time-resolved photoluminescence study of CdTe/MgCdTe double heterostructures on InSb substrates using molecular beam epitaxy

    SciTech Connect (OSTI)

    DiNezza, Michael J.; Liu, Shi; Kirk, Alexander P.; Zhang, Yong-Hang; School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 ; Zhao, Xin-Hao; School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287

    2013-11-04

    CdTe/MgCdTe double heterostructures (DHs) are grown on InSb substrates using molecular beam epitaxy and reveal strong photoluminescence with over double the intensity of a GaAs/AlGaAs DH with an identical layer structure design grown on GaAs. Time-resolved photoluminescence of the CdTe/MgCdTe DH gives a Shockley-Read-Hall recombination lifetime of 86 ns, which is more than one order of magnitude longer than that of typical polycrystalline CdTe films. These findings indicate that monocrystalline CdTe/MgCdTe DHs effectively reduce surface recombination, have limited nonradiative interface recombination, and are promising for solar cells that could reach power conversion efficiencies similar to that of GaAs.

  20. Radiochemical procedures for analysis of Pu, Am, Cs and Sr in water, soil, sediments and biota samples

    SciTech Connect (OSTI)

    Wong, K.M.; Jokela, T.A.; Noshkin, V.E.

    1994-02-01

    The Environmental Radioactivity Analysis Laboratory (ERAL) was established as an analytical facility. The primary function of ERAL is to provide fast and accurate radiological data of environmental samples. Over the years, many radiochemical procedures have been developed by the staffs of ERAL. As result, we have found that our procedures exist in many different formats and in many different notebooks, documents and files. Therefore, in order to provide for more complete and orderly documentation of the radiochemical procedures that are being used by ERAL, we have decided to standardize the format and compile them into a series of reports. This first report covers procedures we have developed and are using for the radiochemical analysis of Pu, Am, Cs, and Sr in various matrices. Additional analytical procedures and/or revisions for other elements will be reported as they become available through continuation of these compilation efforts.

  1. Relativistic energy density functionals: Low-energy collective states of {sup 240}Pu and {sup 166}Er

    SciTech Connect (OSTI)

    Li, Z. P.; Niksic, T.; Vretenar, D.; Ring, P.; Meng, J.

    2010-06-15

    The empirical relativistic density-dependent, point-coupling energy density functional, adjusted exclusively to experimental binding energies of a large set of deformed nuclei with Aapprox =150-180 and Aapprox =230-250, is tested with spectroscopic data for {sup 166}Er and {sup 240}Pu. Starting from constrained self-consistent triaxial relativistic Hartree-Bogoliubov calculations of binding energy maps as functions of the quadrupole deformation in the beta-gamma plane, excitation spectra and E2 transition probabilities are calculated as solutions of the corresponding microscopic collective Hamiltonian in five dimensions for quadrupole vibrational and rotational degrees of freedom and compared with available data on low-energy collective states.

  2. LWR spent fuel reduction by the removal of U and the compact storage of Pu with FP for long-term nuclear sustainability

    SciTech Connect (OSTI)

    Fukasawa, T.; Hoshino, K.; Takano, M.; Sato, S.; Shimazu, Y.

    2013-07-01

    Fast breeder reactors (FBR) nuclear fuel cycle is needed for long-term nuclear sustainability while preventing global warming and maximum utilizing the limited uranium (U) resources. The 'Framework for Nuclear Energy Policy' by the Japanese government on October 2005 stated that commercial FBR deployment will start around 2050 under its suitable conditions by the successive replacement of light water reactors (LWR) to FBR. Even after Fukushima Daiichi Nuclear Power Plant accident which made Japanese tendency slow down the nuclear power generation activities, Japan should have various options for energy resources including nuclear, and also consider the delay of FBR deployment and increase of LWR spent fuel (LWR-SF) storage amounts. As plutonium (Pu) for FBR deployment will be supplied from LWR-SF reprocessing and Japan will not possess surplus Pu, the authors have developed the flexible fuel cycle initiative (FFCI) for the transition from LWR to FBR. The FFCI system is based on the possibility to stored recycled materials (U, Pu)temporarily for a suitable period according to the FBR deployment rate to control the Pu demand/supply balance. This FFCI system is also effective after the Fukushima accident for the reduction of LWR-SF and future LWR-to-FBR transition. (authors)

  3. Current enhancement of CdTe-based solar cells

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

    Paudel, Naba R.; Poplawsky, Jonathan D.; More, Karren Leslie; Yan, Yanfa

    2015-07-30

    We report on the realization of CdTe solar cell photocurrent enhancement using an n-type CdSe heterojunction partner sputtered on commercial SnO2/SnO2:F coated soda-lime glass substrates. With high-temperature close-space sublimation CdTe deposition followed by CdCl2 activation, this thin-film stack allows for substantial interdiffusion at the CdSe/CdTe interface facilitating a CdSexTe1-x alloy formation. The bowing effect causes a reduced optical bandgap of the alloyed absorber layer and, therefore, leads to current enhancement in the long-wavelength region and a decrease in open-circuit voltage (VOC). To overcome the VOC loss and maintain a high short-circuit current (JSC), the CdTe cell configuration has been modifiedmore » using combined CdS:O/CdSe window layers. The new device structure has demonstrated enhanced collection from both short-and long-wavelength regions as well as a VOC improvement. With an optimized synthesis process, a small-area cell using CdS:O/CdSe window layer showed an efficiency of 15.2% with a VOC of 831 mV, a JSC of 26.3 mA/cm2, and a fill factor of 69.5%, measured under an AM1.5 illumination without antireflection coating. Furthermore, the results provide new directions for further improvement of CdTe-based solar cells.« less

  4. Probing TeV physics in the structure of the neutron (Technical...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Probing TeV physics in the structure of the neutron Citation Details In-Document Search Title: Probing TeV physics in the structure of the neutron You are...

  5. CdTe Thin Film Solar Cells and Modules Tutorial; NREL (National Renewable Energy Laboratory)

    SciTech Connect (OSTI)

    Albin, David S.

    2015-06-13

    This is a tutorial presented at the 42nd IEEE Photovoltaics Specialists Conference to cover the introduction, background, and updates on CdTe cell and module technology, including CdTe cell and module structure and fabrication.

  6. CsBi4Te6: A High-Performance Thermoelectric Material for Low...

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

    thermoelectric properties of CsBi(4)Te(6) appear to match or exceed those of Bi(2-x)Sb(x)Te(3-y)Se(y) alloys. URL: Link to article - National Center for Biotechnology Information...

  7. Probing TeV physics in the structure of the neutron (Technical...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Probing TeV physics in the structure of the neutron Citation Details In-Document Search Title: Probing TeV physics in the structure of the neutron Authors: Gupta, ...

  8. Pressure-induced Phase Transition in Thiol-capped CdTe Nanoparticles

    SciTech Connect (OSTI)

    Wu, F; Zaug, J; Young, C; Zhang, J Z

    2006-11-29

    Phase transitions for CdTe nanoparticles (NPs) under high pressure up to 37.0 GPa have been studied using fluorescence measurements. The phase transition from cinnarbar to rocksalt phase has been observed in CdTe NPs solution at 5.8 GPa, which is much higher than the phase transition pressure of bulk CdTe (3.8 GPa) and that of CdTe NPs in solid form (0.8 GPa). CdTe NPs solution therefore shows elevated phase transition pressure and enhanced stability against pressure compared with bulk CdTe and CdTe NPs in solid forms. The enhanced stability of CdTe NPs solution has been attributed to possible shape change in the phase transition and/or inhomogeneous strains in nanoparticle solutions.

  9. Energy Sources for Yotta-TeV Iceberg Showers (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Energy Sources for Yotta-TeV Iceberg Showers Citation Details In-Document Search Title: Energy Sources for Yotta-TeV Iceberg Showers In late February of 2002, warming climate along ...

  10. Efficiency, Cost and Weight Trade-off in TE Power Generation...

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

    Efficiency, Cost and Weight Trade-off in TE Power Generation System for Vehicle Exhaust Applications Efficiency, Cost and Weight Trade-off in TE Power Generation System for Vehicle...

  11. Junction Evolution During Fabrication of CdS/CdTe Thin-film PV Solar Cells (Presentation)

    SciTech Connect (OSTI)

    Gessert, T. A.

    2010-09-01

    Discussion of the formation of CdTe thin-film PV junctions and optimization of CdTe thin-film PV solar cells.

  12. Reverse Monte Carlo simulation of Se{sub 80}Te{sub 20} and Se{sub 80}Te{sub 15}Sb{sub 5} glasses

    SciTech Connect (OSTI)

    Abdel-Baset, A. M.; Rashad, M.; Moharram, A. H.

    2013-12-16

    Two-dimensional Monte Carlo of the total pair distribution functions g(r) is determined for Se{sub 80}Te{sub 20} and Se{sub 80}Te{sub 15}Sb{sub 5} alloys, and then it used to assemble the three-dimensional atomic configurations using the reverse Monte Carlo simulation. The partial pair distribution functions g{sub ij}(r) indicate that the basic structure unit in the Se{sub 80}Te{sub 15}Sb{sub 5} glass is di-antimony tri-selenide units connected together through Se-Se and Se-Te chain. The structure of Se{sub 80}Te{sub 20} alloys is a chain of Se-Te and Se-Se in addition to some rings of Se atoms.

  13. Surfactant-Free Synthesis of Bi?Te?-Te Micro-Nano Heterostructure with Enhanced Thermoelectric Figure of Merit

    SciTech Connect (OSTI)

    Zhang, Yichi; Wang, Heng; Kraemer, Stephan; Shi, Yifeng; Zhang, Fan; Snedaker, Matt; Ding, Kunlun; Moskovits, Martin; Snyder, G. Jeffrey; Stucky, Galen D.

    2011-01-01

    An ideal thermoelectric material would be a semiconductor with high electrical conductivity and relatively low thermal conductivity: an electron crystal, phonon glass. Introducing nanoscale heterostructures into the bulk TE matrix is one way of achieving this intuitively anomalous electron/phonon transport behavior. The heterostructured interfaces are expected to play a significant role in phonon scattering to reduce thermal conductivity and in the energy-dependent scattering of electrical carriers to improve the Seebeck coefficient. A nanoparticle building block assembly approach is plausible to fabricate three-dimensional heterostructured materials on a bulk commercial scale. However, a key problem in applying this strategy is the possible negative impact on TE performance of organic residue from the nanoparticle capping ligands. Herein, we report a wet chemical, surfactant-free, low-temperature, and easily up-scalable strategy for the synthesis of nanoscale heterophase Bi?Te?-Te via a galvanic replacement reaction. The micro-nano heterostructured material is fabricated bottom-up, by mixing the heterophase with commercial Bi?Te?. This unique structure shows an enhanced zT value of ~0.4 at room temperature. This heterostructure has one of the highest figures of merit among bismuth telluride systems yet achieved by a wet chemical bottom-up assembly. In addition, it shows a 40% enhancement of the figure of merit over our lab-made material without nanoscale heterostructures. This enhancement is mainly due to the decrease in the thermal conductivity while maintaining the power factor. Overall, this cost-efficient and room-temperature synthesis methodology provides the potential for further improvement and large-scale thermoelectric applications.

  14. Structural health and prognostics management for offshore wind turbines : case studies of rotor fault and blade damage with initial O&M cost modeling.

    SciTech Connect (OSTI)

    Myrent, Noah J.; Kusnick, Joshua F.; Barrett, Natalie C.; Adams, Douglas E.; Griffith, Daniel Todd

    2013-04-01

    Operations and maintenance costs for offshore wind plants are significantly higher than the current costs for land-based (onshore) wind plants. One way to reduce these costs would be to implement a structural health and prognostic management (SHPM) system as part of a condition based maintenance paradigm with smart load management and utilize a state-based cost model to assess the economics associated with use of the SHPM system. To facilitate the development of such a system a multi-scale modeling approach developed in prior work is used to identify how the underlying physics of the system are affected by the presence of damage and faults, and how these changes manifest themselves in the operational response of a full turbine. This methodology was used to investigate two case studies: (1) the effects of rotor imbalance due to pitch error (aerodynamic imbalance) and mass imbalance and (2) disbond of the shear web; both on a 5-MW offshore wind turbine in the present report. Based on simulations of damage in the turbine model, the operational measurements that demonstrated the highest sensitivity to the damage/faults were the blade tip accelerations and local pitching moments for both imbalance and shear web disbond. The initial cost model provided a great deal of insight into the estimated savings in operations and maintenance costs due to the implementation of an effective SHPM system. The integration of the health monitoring information and O&M cost versus damage/fault severity information provides the initial steps to identify processes to reduce operations and maintenance costs for an offshore wind farm while increasing turbine availability, revenue, and overall profit.

  15. Study of Pu consumption in light water reactors: Evaluation of GE advanced boiling water reactor plants, compilation of Phase 1C task reports

    SciTech Connect (OSTI)

    Not Available

    1994-01-15

    This report summarizes the evaluations conducted during Phase 1C of the Pu Disposition Study have provided further results which reinforce the conclusions reached during Phase 1A & 1B: These conclusions clearly establish the benefits of the fission option and the use of the ABWR as a reliable, proven, well-defined and cost-effective means available to disposition the weapons Pu. This project could be implemented in the near-term at a cost and on a schedule being validated by reactor plants currently under construction in Japan and by cost and schedule history and validated plans for MOX plants in Europe. Evaluations conducted during this phase have established that (1) the MOX fuel is licensable based on existing criteria for new fuel with limited lead fuel rod testing, (2) that the applicable requirements for transport, handling and repository storage can be met, and (3) that all the applicable safeguards criteria can be met.

  16. On the Potential for Vacancy Annihilation as a Mechanism for Conditioning in Pu-1.9 at.% Ga

    SciTech Connect (OSTI)

    Jeffries, J R; Blobaum, K M; Schwartz, A J

    2009-03-09

    The {delta} {yields} {alpha}{prime} martensitic transformation in Pu-1.9 at.% Ga occurs when the alloy is cooled below about -100 C. This transformation exhibits anomalous behavior, where the isothermal transformation proceeds atypically with double-C kinetics. Recent work has revealed that an ambient temperature isothermal hold (referred to as conditioning) prior to the transformation has different effects depending on whether transformation proceeds in the upper- or lower-C of the double-C: the amount of transformation is increased with conditioning in the upper-C, while the transformation in the lower-C seems to be engendered by conditioning. The mechanism by which conditioning affects the low-temperature {delta} {yields} {alpha}{prime} transformation is thus of great importance to understanding the transformation itself as well as the general circumstances that can affect a martensitic phase transformation. Using differential scanning calorimetry measurements, vacancy annihilation as a mechanism for the conditioning effect has been examined. While there are some characteristics of the conditioning effect that are reminiscent of vacancy annihilation, the results of these experiments suggest that vacancy annihilation is not a likely candidate description for the conditioning effect.

  17. Theoretical aspects of the magnetism in the ferromagnetic A Fe sub 2 systems ( A =U, Np, Pu, and Am)

    SciTech Connect (OSTI)

    Eriksson, O.; Johansson, B. ); Brooks, M.S.S. )

    1990-05-01

    We report on spin-polarized energy-band calculations for the cubic Laves-phase systems UFe{sub 2}, NpFe{sub 2}, PuFe{sub 2}, and AmFe{sub 2}. The calculations were performed with the local-density approximation for the exchange and correlation potential together with a term that shifts the one-electron eigenvalues and takes into account the different interelectronic repulsions for electrons with different 5{ital f} magnetic quantum numbers. The spin-orbit interaction was also included in the band Hamiltonian. Thus the parameter-free calculations incorporate Hund's first, second, and third rules. The magnetism in the first three compounds was found to be dominated by a large orbital contribution coupled antiparallel to the spin moment. In the calculations for AmFe{sub 2}, the 5{ital f} electrons were treated as core electrons. The magnetism was here found to behave very much like the magnetism of similar rare-earth Laves-phase compounds.

  18. International Workshop on Gamma Spectrometry Analysis Codes for U and Pu Isotopics: Workshop Results and Next Steps

    SciTech Connect (OSTI)

    McGinnis, Brent R; Solodov, Alexander A; Shipwash, Jacqueline L; Zhernosek, Alena V; McKinney, Teressa L; Pickett, Chris A; Peerani, Paolo

    2009-01-01

    In November 2008, the Institute of Nuclear Materials Management (INMM) and the European Safeguards Research and Development Association (ESARDA) co-hosted the International Workshop on Gamma Spectrometry Analysis Codes for U and Pu Isotopics at the Oak Ridge National Laboratory (ORNL). This workshop was conducted in response to needs expressed by the international safeguards community to understand better the capabilities and limitations of the codes; to ensure these codes are sustained; and to ensure updates or revisions are performed in a controlled manner. The workshop was attended by approximately 100 participants. The participants included code developers, code suppliers, safeguards specialists, domestic and international inspectors, process operators, regulators, and programme sponsors from various government agencies. The workshop provided a unique opportunity for code developers, commercial distributors and end users to interact in a hands-on laboratory environment to develop solutions for programmatic and technical issues associated with the various codes. The workshop also provided an international forum for discussing development of an internationally accepted standard test method. This paper discusses the organization of the workshop, its goals and objectives and feedback received from the participants. The paper also describes the significance of the working group's contribution to improving codes that are commonly used during inspections to verify that nuclear facilities are compliant with treaty obligations that ensure nuclear fuel cycle facilities are used for peaceful purposes.

  19. Modeling of selected ceramic processing parameters employed in the fabrication of 238PuO2 fuel pellets

    SciTech Connect (OSTI)

    Brockman, R. A.; Kramer, D. P.; Barklay, C. D.; Cairns-Gallimore, D.; Brown, J. L.; Huling, J. C.; Van Pelt, C. E.

    2011-10-01

    Recent deep space missions utilize the thermal output of the radioisotope plutonium-238 as the fuel in the thermal to electrical power system. Since the application of plutonium in its elemental state has several disadvantages, the fuel employed in these deep space power systems is typically in the oxide form such as plutonium-238 dioxide (238PuO2). As an oxide, the processing of the plutonium dioxide into fuel pellets is performed via ''classical'' ceramic processing unit operations such as sieving of the powder, pressing, sintering, etc. Modeling of these unit operations can be beneficial in the understanding and control of processing parameters with the goal of further enhancing the desired characteristics of the 238PuO2 fuel pellets. A finite element model has been used to help identify the time-temperature-stress profile within a pellet during a furnace operation taking into account that 238PuO2 itself has a significant thermal output. The results of the modeling efforts will be discussed.

  20. The thermal conductivity of mixed fuel UxPu1-xO2: molecular dynamics simulations

    SciTech Connect (OSTI)

    Liu, Xiang-Yang; Cooper, Michael William Donald; Stanek, Christopher Richard; Andersson, Anders David Ragnar

    2015-10-16

    Mixed oxides (MOX), in the context of nuclear fuels, are a mixture of the oxides of heavy actinide elements such as uranium, plutonium and thorium. The interest in the UO2-PuO2 system arises from the fact that these oxides are used both in fast breeder reactors (FBRs) as well as in pressurized water reactors (PWRs). The thermal conductivity of UO2 fuel is an important material property that affects fuel performance since it is the key parameter determining the temperature distribution in the fuel, thus governing, e.g., dimensional changes due to thermal expansion, fission gas release rates, etc. For this reason it is important to understand the thermal conductivity of MOX fuel and how it differs from UO2. Here, molecular dynamics (MD) simulations are carried out to determine quantitatively, the effect of mixing on the thermal conductivity of UxPu1-xO2, as a function of PuO2 concentrations, for a range of temperatures, 300 1500 K. The results will be used to develop enhanced continuum thermal conductivity models for MARMOT and BISON by INL. These models express the thermal conductivity as a function of microstructure state-variables, thus enabling thermal conductivity models with closer connection to the physical state of the fuel.

  1. Quantum oscillations in a two-dimensional electron gas at the rocksalt/zincblende interface of PbTe/CdTe (111) heterostructures.

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

    Zhang, Bingpo; Lu, Ping; Liu, Henan; Jiao, Lin; Ye, Zhenyu; Jaime, M.; Balakirev, F. F.; Yuan, Huiqiu; Wu, Huizhen; Pan, Wei; et al

    2015-06-05

    Quantum oscillations are observed in the 2DEG system at the interface of novel heterostructures, PbTe/CdTe (111), with nearly identical lattice parameters (aPbTe = 0.6462 nm, aCdTe = 0.648 nm) but very different lattice structures (PbTe: rock salt, CdTe: zinc blende). The 2DEG formation mechanism, a mismatch in the bonding configurations of the valence electrons at the interface, is uniquely different from the other known 2DEG systems. The aberration-corrected scanning transmission electron microscope (AC-STEM) characterization indicates an abrupt interface without cation interdiffusion due to a large miscibility gap between the two constituent materials. As a result, electronic transport measurements under magneticmore » field up to 60 T, with the observation of Landau level filling factor ν = 1, unambiguously reveal a π Berry phase, suggesting the Dirac Fermion nature of the 2DEG at the heterostructure interface, and the PbTe/CdTe heterostructure being a new candidate for 2D topological crystalline insulators.« less

  2. ~~~~: Gmt Lakes Cat-bar) ALTERNaTE I

    Office of Legacy Management (LM)

    ~~~: Gmt Lakes Cat-bar) ALTERNaTE I --------------------------------------- NAME: 333 Iv. Mkhi qr) Aw. thka o ~~~---~~~--~~~_-----__ C I TV : 8 Morim 'Love 82 10 bhh &Q Ir -+----------- STATE- fL I - ------ l OWNER(S) -__----_ past: Current: I --------------------____ Owner contacted q yes p no; _____--_____-____------~~~l if yes, data contacted -_--------__- TYPE OF OPERATION ---_------------- 0 Research & Development q Production scale testing 0 Pilot Scale 0 Bench Scale process 0

  3. Diameter dependent thermoelectric properties of individual SnTe nanowires

    SciTech Connect (OSTI)

    Xu, E. Z.; Li, Z.; Martinez, J. A.; Sinitsyn, N.; Htoon, H.; Li, Nan; Swartzentruber, B.; Hollingsworth, J. A.; Wang, Jian; Zhang, S. X.

    2015-01-15

    The lead-free compound tin telluride (SnTe) has recently been suggested to be a potentially promising thermoelectric material because of its similar electronic band structure as the well-known lead telluride. Here we report on the first thermoelectric study of individual single crystalline SnTe nanowires (NWs) with different diameters ranging from ~200 to ~1000 nm. Measurements of thermopower S, electrical conductivity ?, and thermal conductivity ? were carried out on the same nanowires over a temperature range of 25 - 300 K. While ? does not show a strong diameter dependence, the thermopower increases by a factor of 2 when the nanowire diameter is decreased from 1000 nm to 200 nm. The thermal conductivities of the measured NWs are only about half of that of the bulk SnTe, which may arise from the enhanced phonon-grain boundary and phonon-defect scatterings. Temperature dependent figure-of-merit ZT was determined and the maximum value at room temperature is ~3 times higher than what was obtained in bulk samples of comparable carrier density.

  4. Diameter dependent thermoelectric properties of individual SnTe nanowires

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

    Xu, E. Z.; Li, Z.; Martinez, J. A.; Sinitsyn, N.; Htoon, H.; Li, Nan; Swartzentruber, B.; Hollingsworth, J. A.; Wang, Jian; Zhang, S. X.

    2015-01-15

    The lead-free compound tin telluride (SnTe) has recently been suggested to be a potentially promising thermoelectric material because of its similar electronic band structure as the well-known lead telluride. Here we report on the first thermoelectric study of individual single crystalline SnTe nanowires (NWs) with different diameters ranging from ~200 to ~1000 nm. Measurements of thermopower S, electrical conductivity σ, and thermal conductivity κ were carried out on the same nanowires over a temperature range of 25 - 300 K. While σ does not show a strong diameter dependence, the thermopower increases by a factor of 2 when the nanowiremore » diameter is decreased from 1000 nm to 200 nm. The thermal conductivities of the measured NWs are only about half of that of the bulk SnTe, which may arise from the enhanced phonon-grain boundary and phonon-defect scatterings. Temperature dependent figure-of-merit ZT was determined and the maximum value at room temperature is ~3 times higher than what was obtained in bulk samples of comparable carrier density.« less

  5. Post-Growth Annealing of Bridgman-grown CdZnTe and CdMnTe Crystals for Room-temperature Nuclear Radiation Detectors

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

    Egarievwe, Stephen U.; Yang, Ge; Egarievwe, Alexander; Okwechime, Ifechukwude O.; Gray, Justin; Hales, Zaveon M.; Hossain, Anwar; Camarda, Guiseppe S.; Bolotnikov, Aleksey E.; James, Ralph B.

    2015-02-11

    Bridgman-grown cadmium zinc telluride (CdZnTe or CZT) and cadmium manganese telluride (CdMnTe or CMT) crystals often have Te inclusions that limit their performances as X-ray- and gamma-ray-detectors. We present here the results of post-growth thermal annealing aimed at reducing and eliminating Te inclusions in them. In a 2D analysis, we observed that the sizes of the Te inclusions declined to 92% during a 60-h annealing of CZT at 510 °C under Cd vapor. Further, tellurium inclusions were eliminated completely in CMT samples annealed at 570 °C in Cd vapor for 26 h, whilst their electrical resistivity fell by an ordermore » of 102. During the temperature-gradient annealing of CMT at 730 °C and an 18 °C/cm temperature gradient for 18 h in a vacuum of 10-5 mbar, we observed the diffusion of Te from the sample, causing a reduction in size of the Te inclusions. For CZT samples annealed at 700 °C in a 10 °C/cm temperature gradient, we observed the migration of Te inclusions from a low-temperature region to a high one at 0.022 μm/s. During the temperature-gradient annealing of CZT in a vacuum of 10-5 mbar at 570 °C and 30 °C/cm for 18 h, some Te inclusions moved toward the high-temperature side of the wafer, while other inclusions of the same size, i.e., 10 µm in diameter, remained in the same position. These results show that the migration, diffusion, and reaction of Te with Cd in the matrix of CZT- and CMT-wafers are complex phenomena that depend on certain conditions.« less

  6. Delayed Fission Gamma-ray Characteristics of Th-232 U-233 U-235 U-238 and Pu-239

    SciTech Connect (OSTI)

    Lane, Taylor; Parma, Edward J.

    2015-08-01

    Delayed fission gamma-rays play an important role in determining the time dependent ioniz- ing dose for experiments in the central irradiation cavity of the Annular Core Research Reactor (ACRR). Delayed gamma-rays are produced from both fission product decay and from acti- vation of materials in the core, such as cladding and support structures. Knowing both the delayed gamma-ray emission rate and the time-dependent gamma-ray energy spectrum is nec- essary in order to properly determine the dose contributions from delayed fission gamma-rays. This information is especially important when attempting to deconvolute the time-dependent neutron, prompt gamma-ray, and delayed gamma-ray contribution to the response of a diamond photo-conducting diode (PCD) or fission chamber in time frames of milliseconds to seconds following a reactor pulse. This work focused on investigating delayed gamma-ray character- istics produced from fission products from thermal, fast, and high energy fission of Th-232, U-233, U-235, U-238, and Pu-239. This work uses a modified version of CINDER2008, a transmutation code developed at Los Alamos National Laboratory, to model time and energy dependent photon characteristics due to fission. This modified code adds the capability to track photon-induced transmutations, photo-fission, and the subsequent radiation caused by fission products due to photo-fission. The data is compared against previous work done with SNL- modified CINDER2008 [ 1 ] and experimental data [ 2 , 3 ] and other published literature, includ- ing ENDF/B-VII.1 [ 4 ]. The ability to produce a high-fidelity (7,428 group) energy-dependent photon fluence at various times post-fission can improve the delayed photon characterization for radiation effects tests at research reactors, as well as other applications.

  7. Noble gas component organization in Apollo 14 breccia 14318: /sup 129/I and /sup 244/Pu regolith chronology

    SciTech Connect (OSTI)

    Swindle, T.D.; Caffee, M.W.; Hohenberg, C.M.; Hudson, G.B.; Laul, J.C.; Simon, S.B.; Papike, J.J.

    1985-02-15

    Noble gas, petrological, and chemical studies made on grain-size separates from lunar regolith breccia 14318 demonstrate that the noble gases are organized into two functional components, volume-correlated and surface-correlated. As in regolith breccia 14301, volume-correlated xenon in 14318 is primarily spallation-derived and the surface-correlated component contains not only solar wind xenon but also significant amounts of ''parentless' xenon from the fission of now extinct /sup 244/Pu and the decay of now extinct /sup 129/I (''parentless'' means the daughter products were incorporated onto grain surfaces following decay of the parent nuclide elsewhere). The ratio of /sup 129/Xe//sup 136/Xe in the total surface-correlated parentless component, as identified in grain-size analysis, is substantially higher than in the least tightly bound parentless component identified in stepwise heating analyses, confirming the trend seen in 14301. If the order of release of gases in stepwise heating is related to the order of incorporation in the simplest way (first in, last out), incorporation of these grain-surface components was probably time-ordered. The /sup 129/Xe//sup 136/Xe ratio in each identifiable parentless component would then be characteristic of the xenon available for surface adsorption at the particular time of acquisition. Continuous variations in this ratio further suggest that incorporation of the parentless xenon was closely coupled with production. Such observations provide the basis for a new chronometer from which we conclude that acquisition of parentless xenon was an ongoing process spanning at least 90 m.y., beginning no more than 44 +- 34 m.y. after the formation of the most meteorites and possibly predating xenon acquisition for the earth.

  8. A W' boson near 2 TeV: Predictions for run 2 of the LHC

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

    Dobrescu, Bogdan A.; Liu, Zhen

    2015-11-20

    We present a renormalizable theory that includes a W' boson of mass in the 1.8–2 TeV range, which may explain the excess events reported by the ATLAS Collaboration in a WZ final state, and by the CMS Collaboration in e+e– jj, Wh0, and jj final states. The W' boson couples to right-handed quarks and leptons, including Dirac neutrinos with TeV-scale masses. This theory predicts a Z' boson of mass in the 3.4–4.5 TeV range. The cross section times branching fractions for the narrow Z' dijet and dilepton peaks at the 13 TeV LHC are 10 and 0.6 fb, respectively, formore » MZ'=3.4 TeV, and an order of magnitude smaller for MZ'=4.5 TeV.« less

  9. Charge transfer and mobility enhancement at CdO/SnTe heterointerfaces

    SciTech Connect (OSTI)

    Nishitani, Junichi; Yu, Kin Man; Walukiewicz, Wladek

    2014-09-29

    We report a study of the effects of charge transfer on electrical properties of CdO/SnTe heterostructures. A series of structures with variable SnTe thicknesses were deposited by RF magnetron sputtering. Because of an extreme type III band offset with the valence band edge of SnTe located at 1.5?eV above the conduction band edge of CdO, a large charge transfer is expected at the interface of the CdO/SnTe heterostructure. The electrical properties of the heterostructures are analyzed using a multilayer charge transport model. The analysis indicates a large 4-fold enhancement of the CdO electron mobility at the interface with SnTe. The mobility enhancement is attributed to reduction of the charge center scattering through neutralization of the donor-like defects responsible for the Fermi level pinning at the CdO/SnTe interface.

  10. The Effect of Structural Vacancies on the Thermoelectric Properties of (Cu2Te)1-x(Ga2Te3)x

    SciTech Connect (OSTI)

    Ye, Zuxin; Cho, Jung Y; Tessema, Misle; Salvador, James R.; Waldo, Richard; Wang, Hsin; Cai, Wei

    2013-01-01

    We have studied the effects of structural vacancies on the thermoelectric properties of the ternary compounds (Cu2Te)1-x(Ga2Te3)x (x = 0.5, 0.55, 0.571, 0.6, 0.625, 0.667 and 0.75), which are solid solutions found in the pseudo-binary phase diagram for Cu2Te and Ga2Te3. This system possesses tunable structural vacancy concentrations. The x= 0.5 phase, CuGaTe2, is nominally devoid of structural vacancies, while the rest of the compounds contain varying amounts of these features, and the volume density of vacancies increases with Ga2Te3 content. The sample with x = 0.5, 0.55, 0.571, 0.6, 0.625 crystallize in the chalcopyrite structure while the x = 0.667 and 0.75 adopt the Ga2Te3 defect zinc blende structure. Strong scattering of heat carrying phonons by structural defects, leads to the reduction of thermal conductivity, which is beneficial to the thermoelectric performance of materials. On the other hand, these defects also scatter charge carriers and reduce the electrical conductivity. All the samples investigated are p-type semiconductors as inferred by the signs of their respective Hall (RH) and Seebeck (S) coefficients. The structural vacancies were found to scatter phonons strongly, while a combination of increased carrier concentration, and vacancies decreases the Hall mobility ( H), degrading the overall thermoelectric performance. The room temperature H drops from 90 cm2/V s for CuGaTe2 to 13 cm2/V s in Cu9Ga11Te21 and 4.6 cm2/V s in CuGa3Te5. The low temperature thermal conductivity decreases significantly with higher Ga2Te3 concentrations (higher vacancy concentration) due to increased point defect scattering which dominate thermal resistance terms. At high temperatures, the dependence of thermal conductivity on the Ga2Te3 content is less significant. The presence of strong Umklapp scattering leads to low thermal conductivity at high temperatures for all samples investigated. The highest ZT among the samples in this study was found for the defect-free CuGaTe2 with ZT ~ 1.0 at 840K.

  11. Microstructure and Thermoelectric Properties of Mechanically Robust PbTe-Si

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

    Eutectic Composites | Energy Frontier Research Centers Microstructure and Thermoelectric Properties of Mechanically Robust PbTe-Si Eutectic Composites Home Author: J. R. Sootsman, J. He, V. P. Dravid, S. Ballikaya, D. Vermeulen, C. Uher, M. G. Kanatzidis Year: 2010 Abstract: The microstructure and thermoelectric properties of the PbTe-Si eutectic system are presented in detail. When rapidly quenched from the melt this system yields materials with thermoelectric properties similar to PbTe

  12. Component Overpressure Growth and Characterization of High Resistivity CdTe

    Office of Scientific and Technical Information (OSTI)

    Crystals for Radiation Detectors (Journal Article) | SciTech Connect Component Overpressure Growth and Characterization of High Resistivity CdTe Crystals for Radiation Detectors Citation Details In-Document Search Title: Component Overpressure Growth and Characterization of High Resistivity CdTe Crystals for Radiation Detectors Spectrometer-grade CdTe single crystals with resistivities higher than 10{sup 9} {Omega} cm have been grown by the modified Bridgman method using zone-refined

  13. High Efficiency Single Crystal CdTe Solar Cells: November 19, 2009 - January 31, 2011

    SciTech Connect (OSTI)

    Carmody, M.; Gilmore, A.

    2011-05-01

    The goal of the program was to develop single crystal CdTe-based top cells grown on Si solar cells as a platform for the subsequent manufacture of high efficiency tandem cells for CPV applications. The keys to both the single junction and the tandem junction cell architectures are the ability to grow high quality single-crystal CdTe and CdZnTe layers on p-type Si substrates, to dope the CdTe and CdZnTe controllably, both n and p-type, and to make low resistance ohmic front and back contacts. EPIR demonstrated the consistent MBE growth of CdTe/Si and CdZnTe/Si having high crystalline quality despite very large lattice mismatches; epitaxial CdTe/Si and CdZnTe/Si consistently showed state-of-the-art electron mobilities and good hole mobilities; bulk minority carrier recombination lifetimes of unintentionally p-doped CdTe and CdZnTe grown by MBE on Si were demonstrated to be consistently of order 100 ns or longer; desired n- and p-doping levels were achieved; solar cell series specific resistances <10 ?-cm2 were achieved; A single-junction solar cell having a state-of-the-art value of Voc and a unverified 16.4% efficiency was fabricated from CdZnTe having a 1.80 eV bandgap, ideal for the top junction in a tandem cell with a Si bottom junction.

  14. Characterization and Analysis of CIGS and CdTE Solar Cells: December 2004 - July 2008

    SciTech Connect (OSTI)

    Sites, J. R.

    2009-01-01

    The work reported here embodies a device-physics approach based on careful measurement and interpretation of data from CIGS and CdTe solar cells.

  15. Nanoscale imaging of photocurrent and efficiency in CdTe solar...

    Office of Scientific and Technical Information (OSTI)

    cells The local collection characteristics of grain interiors and grain boundaries in thin film CdTe polycrystalline solar cells are investigated using scanning photocurrent...

  16. Analysis of Surface Chemistry and Detector Performance of Chemically Process CdZnTe crystals

    SciTech Connect (OSTI)

    HOSSAIN A.; Yang, G.; Sutton, J.; Zergaw, T.; Babalola, O. S.; Bolotnikov, A. E.; Camarda. ZG. S.; Gul, R.; Roy, U. N., and James, R. B.

    2015-10-05

    The goal is to produce non-conductive smooth surfaces for fabricating low-noise and high-efficiency CdZnTe devices.

  17. High Efficiency CdTe and CIGS Thin Film Solar Cells: Highlights...

    Office of Scientific and Technical Information (OSTI)

    High Efficiency CdTe and CIGS Thin Film Solar Cells: Highlights of the Technologies Challenges Acknowledgement: Work performed at NREL for US DOE under contract No....

  18. Nanoscale imaging of photocurrent and efficiency in CdTe solar...

    Office of Scientific and Technical Information (OSTI)

    Administration (NNSA) Country of Publication: United States Language: English Subject: 14 SOLAR ENERGY photovoltaics; CdTe; scanning photocurrent microscopy; solar cells; NSOM Word...

  19. Scandium resonant impurity level in PbTe

    SciTech Connect (OSTI)

    Skipetrov, E. P. Skipetrova, L. A.; Knotko, A. V.; Slynko, E. I.; Slynko, V. E.

    2014-04-07

    We synthesize a scandium-doped PbTe single-crystal ingot and investigate the phase and the elemental composition as well as galvanomagnetic properties of Pb{sub 1-y}Sc{sub y}Te alloys in weak magnetic fields (4.2?K???T???300?K, B???0.07?T) upon varying the scandium content (y???0.02). We find that all investigated samples are single-phase and n-type. The distribution of scandium impurities along the axis of the ingot is estimated to be exponential. An increase of scandium impurity content leads to a monotonous growth of the free electron concentration by four orders of magnitude (approximately from 10{sup 16}?cm{sup ?3} to 10{sup 20}?cm{sup ?3}). In heavily doped alloys (y?>?0.01), the free electron concentration at the liquid-helium temperature tends to saturation, indicating the pinning of the Fermi energy by the scandium resonant impurity level located on the background of the conduction band. Using the two-band Kane and six-band Dimmock dispersion relations for IV-VI semiconductors, dependences of the Fermi energy measured from the bottom of the conduction band E{sub c} on the scandium impurity content are calculated and the energy of the resonant scandium level is estimated to be E{sub Sc}???E{sub c}?+?280?meV. Diagrams of electronic structure rearrangement of Pb{sub 1-y}Sc{sub y}Te alloys upon doping are proposed.

  20. Mr. John E. Kieling, Chief Hazardous Was te Bureau

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

    John E. Kieling, Chief Hazardous Was te Bureau Depa rtment of Energy Carlsbad Field Office P. O. Box 3090 Carlsbad , New Mexico 88221 NOV 0 5 2013 New Mexico Environment Department 2905 Rodeo Park Drive East. Building 1 Santa Fe, New Mexico 87505-6303 Subject: Panel 6 Closure and Final Waste Emplacement Notifications Dear Mr. Kieling : The purpose of this leiter is 1 0 notify th e New Mexico Environment Department (NMEO) that the Permittees intend to commence closure of Hazardous Waste Disposa

  1. Radiolysis of Salts and Long-Term Storage Issues for Both Pure and Impure PuO{sub 2} Materials in Plutonium Storage Containers

    SciTech Connect (OSTI)

    Lav Tandon

    2000-05-01

    The Material Identification and Surveillance (MIS) project sponsored a literature search on the effects of radiation on salts, with focus on alkali chlorides. The goal of the survey was to provide a basis for estimating the magnitude of {alpha} radiation effects on alkali chlorides that can accompany plutonium oxide (PuO{sub 2}) into storage. Chloride radiolysis can yield potentially corrosive gases in plutonium storage containers that can adversely affect long-term stability. This literature search was primarily done to provide a tutorial on this topic, especially for personnel with nonradiation chemistry backgrounds.

  2. Photoconductivity of CdTe Nanocrystal-Based Thin Films. Te2- Ligands Lead To Charge Carrier Diffusion Lengths Over 2 Micrometers

    SciTech Connect (OSTI)

    Crisp, Ryan W.; Callahan, Rebecca; Reid, Obadiah G.; Dolzhnikov, Dmitriy S.; Talapin, Dmitri V.; Rumbles, Garry; Luther, Joseph M.; Kopidakis, Nikos

    2015-11-16

    We report on photoconductivity of films of CdTe nanocrystals (NCs) using time-resolved microwave photoconductivity (TRMC). Spherical and tetrapodal CdTe NCs with tunable size-dependent properties are studied as a function of surface ligand (including inorganic molecular chalcogenide species) and annealing temperature. Relatively high carrier mobility is measured for films of sintered tetrapod NCs (4 cm2/(V s)). Our TRMC findings show that Te2- capped CdTe NCs show a marked improvement in carrier mobility (11 cm2/(V s)), indicating that NC surface termination can be altered to play a crucial role in charge-carrier mobility even after the NC solids are sintered into bulk films.

  3. Extending Higgs inflation with TeV scale new physics

    SciTech Connect (OSTI)

    He, Hong-Jian; Xianyu, Zhong-Zhi E-mail: xianyuzhongzhi@gmail.com

    2014-10-01

    Higgs inflation is among the most economical and predictive inflation models, although the original Higgs inflation requires tuning the Higgs or top mass away from its current experimental value by more than 2? deviations, and generally gives a negligible tensor-to-scalar ratio r?10{sup -3} (if away from the vicinity of critical point). In this work, we construct a minimal extension of Higgs inflation, by adding only two new weak-singlet particles at TeV scale, a vector-quark T and a real scalar S. The presence of singlets (T,S) significantly impact the renormalization group running of the Higgs boson self-coupling. With this, our model provides a wider range of the tensor-to-scalar ratio r=O(0.1)-O(10{sup -3}), consistent with the favored r values by either BICEP2 or Planck data, while keeping the successful prediction of the spectral index n{sub s}?0.96. It allows the Higgs and top masses to fully fit the collider measurements. We also discuss implications for searching the predicted TeV-scale vector-quark T and scalar S at the LHC and future high energy pp colliders.

  4. Thermodynamic properties of model CdTe/CdSe mixtures

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

    van Swol, Frank; Zhou, Xiaowang W.; Challa, Sivakumar R.; Martin, James E.

    2015-02-20

    We report on the thermodynamic properties of binary compound mixtures of model groups II–VI semiconductors. We use the recently introduced Stillinger–Weber Hamiltonian to model binary mixtures of CdTe and CdSe. We use molecular dynamics simulations to calculate the volume and enthalpy of mixing as a function of mole fraction. The lattice parameter of the mixture closely follows Vegard's law: a linear relation. This implies that the excess volume is a cubic function of mole fraction. A connection is made with hard sphere models of mixed fcc and zincblende structures. We found that the potential energy exhibits a positive deviation frommore » ideal soluton behaviour; the excess enthalpy is nearly independent of temperatures studied (300 and 533 K) and is well described by a simple cubic function of the mole fraction. Using a regular solution approach (combining non-ideal behaviour for the enthalpy with ideal solution behaviour for the entropy of mixing), we arrive at the Gibbs free energy of the mixture. The Gibbs free energy results indicate that the CdTe and CdSe mixtures exhibit phase separation. The upper consolute temperature is found to be 335 K. Finally, we provide the surface energy as a function of composition. Moreover, it roughly follows ideal solution theory, but with a negative deviation (negative excess surface energy). This indicates that alloying increases the stability, even for nano-particles.« less

  5. Purification of CdZnTe by Electromigration

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

    Kim, K.; Kim, Sangsu; Hong, Jinki; Lee, Jinseo; Hong, Taekwon; Bolotnikov, A. E.; Camarda, G. S.; James, R. B.

    2015-04-14

    Electro-migration of ionized/electrically active impurities in CdZnTe (CZT) was successfully demonstrated at elevated temperature with an electric field of 20 V/mm. Copper, which exists in positively charged states, electro-migrated at a speed of 15 lm/h in an electric field of 20 V/mm. A notable variation in impurity concentration along the growth direction with the segregation tendency of the impurities was observed in an electro-migrated CZT boule. Notably, both Ga and Fe, which exist in positively charged states, exhibited the opposite distribution to that of their segregation tendency in Cd(Zn)Te. Furthermore, a CZT detector fabricated from the middle portion of themore » electromigrated CZT boule showed an improved mobility-lifetime product of 0.91 10-2 cm2 /V, compared to that of 1.4 10-3 cm2 /V, observed in an as-grown (non-electro-migrated) CZT detector. The optimum radiation detector material would have minimum concentration of deep traps required for compensation.« less

  6. Extending Higgs inflation with TeV scale new physics

    SciTech Connect (OSTI)

    He, Hong-Jian; Xianyu, Zhong-Zhi

    2014-10-10

    Higgs inflation is among the most economical and predictive inflation models, although the original Higgs inflation requires tuning the Higgs or top mass away from its current experimental value by more than 2σ deviations, and generally gives a negligible tensor-to-scalar ratio r∼10{sup −3} (if away from the vicinity of critical point). In this work, we construct a minimal extension of Higgs inflation, by adding only two new weak-singlet particles at TeV scale, a vector-quark T and a real scalar S . The presence of singlets (T, S) significantly impact the renormalization group running of the Higgs boson self-coupling. With this, our model provides a wider range of the tensor-to-scalar ratio r=O(0.1)−O(10{sup −3}) , consistent with the favored r values by either BICEP2 or Planck data, while keeping the successful prediction of the spectral index n{sub s}≃0.96 . It allows the Higgs and top masses to fully fit the collider measurements. We also discuss implications for searching the predicted TeV-scale vector-quark T and scalar S at the LHC and future high energy pp colliders.

  7. Advanced CdTe Photovoltaic Technology: September 2007 - March 2009

    SciTech Connect (OSTI)

    Barth, K.

    2011-05-01

    During the last eighteen months, Abound Solar (formerly AVA Solar) has enjoyed significant success under the SAI program. During this time, a fully automated manufacturing line has been developed, fabricated and commissioned in Longmont, Colorado. The facility is fully integrated, converting glass and semiconductor materials into complete modules beneath its roof. At capacity, a glass panel will enter the factory every 10 seconds and emerge as a completed module two hours later. This facility is currently undergoing trials in preparation for large volume production of 120 x 60 cm thin film CdTe modules. Preceding the development of the large volume manufacturing capability, Abound Solar demonstrated long duration processing with excellent materials utilization for the manufacture of high efficiency 42 cm square modules. Abound Solar prototype modules have been measured with over 9% aperture area efficiency by NREL. Abound Solar demonstrated the ability to produce modules at industry leading low costs to NREL representatives. Costing models show manufacturing costs below $1/Watt and capital equipment costs below $1.50 per watt of annual manufacturing capacity. Under this SAI program, Abound Solar supported a significant research and development program at Colorado State University. The CSU team continues to make progress on device and materials analysis. Modeling for increased device performance and the effects of processing conditions on properties of CdTe PV were investigated.

  8. Fabrication and Physics of CdTe Devices by Sputtering: Final Report, 1 March 2005 - 30 November 2008

    SciTech Connect (OSTI)

    Compaan, A.; Collins, R.; Karpov, V.; Giolando, D.

    2009-04-01

    Work to understand CdS/CdTe solar cell device physics; increase magnetron sputtering rate (while keeping high device quality); reduce thickness of CdTe layers (while keeping voltage and fill factor).

  9. Growth of CdTe thin films on graphene by close-spaced sublimation method

    SciTech Connect (OSTI)

    Jung, Younghun; Yang, Gwangseok; Kim, Jihyun, E-mail: hyunhyun7@korea.ac.kr [Department of Chemical and Biological Engineering, Korea University, Seoul 136-701 (Korea, Republic of)] [Department of Chemical and Biological Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Chun, Seungju; Kim, Donghwan [Department of Materials Science and Engineering, Korea University, Seoul 136-701 (Korea, Republic of)] [Department of Materials Science and Engineering, Korea University, Seoul 136-701 (Korea, Republic of)

    2013-12-02

    CdTe thin films grown on bi-layer graphene were demonstrated by using the close-spaced sublimation method, where CdTe was selectively grown on the graphene. The density of the CdTe domains was increased with increasing the number of the defective sites in the graphene, which was controlled by the duration of UV exposure. The CdTe growth rate on the bi-layer graphene electrodes was 400?nm/min with a bandgap energy of 1.451.49?eV. Scanning electron microscopy, micro-Raman spectroscopy, micro-photoluminescence, and X-ray diffraction technique were used to confirm the high quality of the CdTe thin films grown on the graphene electrodes.

  10. Fission Product Yields of {sup 233}U, {sup 235}U, {sup 238}U and {sup 239}Pu in Fields of Thermal Neutrons, Fission Neutrons and 14.7-MeV Neutrons

    SciTech Connect (OSTI)

    Laurec, J.; Adam, A.; Bruyne, T. de [Commissariat a l'Energie Atomique, Centre DAM-Ile de France (CEA DAM DIF), 91297 Arpajon (France); Bauge, E., E-mail: eric.bauge@cea.f [Commissariat a l'Energie Atomique, Centre DAM-Ile de France (CEA DAM DIF), 91297 Arpajon (France); Granier, T.; Aupiais, J.; Bersillon, O.; Le Petit, G. [Commissariat a l'Energie Atomique, Centre DAM-Ile de France (CEA DAM DIF), 91297 Arpajon (France); Authier, N.; Casoli, P. [Commissariat a l'Energie Atomique, Centre de Valduc, 21120 Is-sur-Tille (France)

    2010-12-15

    The yields of more than fifteen fission products have been carefully measured using radiochemical techniques, for {sup 235}U(n,f), {sup 239}Pu(n,f) in a thermal spectrum, for {sup 233}U(n,f), {sup 235}U(n,f), and {sup 239}Pu(n,f) reactions in a fission neutron spectrum, and for {sup 233}U(n,f), {sup 235}U(n,f), {sup 238}U(n,f), and {sup 239}Pu(n,f) for 14.7 MeV monoenergetic neutrons. Irradiations were performed at the EL3 reactor, at the Caliban and Prospero critical assemblies, and at the Lancelot electrostatic accelerator in CEA-Valduc. Fissions were counted in thin deposits using fission ionization chambers. The number of fission products of each species were measured by gamma spectrometry of co-located thick deposits.

  11. Measurement/Evaluation Techniques and Nuclear Data Associated with Fission of 239Pu by Fission Spectrum Neutrons

    SciTech Connect (OSTI)

    Baisden, P; Bauge, E; Ferguson, J; Gilliam, D; Granier, T; Jeanloz, R; McMillan, C; Robertson, D; Thompson, P; Verdon, C; Wilkerson, C; Young, P

    2010-03-16

    This Panel was chartered to review and assess new evaluations of work on fission product data, as well as the evaluation process used by the two U.S. nuclear weapons physics laboratories. The work focuses on fission product yields resulting from fission spectrum neutrons incident on plutonium, and includes data from measurements that had not been previously published as well as new or revised fission product cumulative yield data, and related quantities such as Q values and R values. This report documents the Panel's assessment of the work presented by Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL). Based on the work presented we have seven key observations: (1) Experiments conducted in the 1970s at LANL, some of which were performed in association with a larger, NIST-led, program, have recently been documented. A preliminary assessment of this work, which will be referred to in this document as ILRR-LANL, shows it to be technically sound. (2) LLNL has done a thorough, unbiased review and evaluation of the available literature and is in the process of incorporating the previously unavailable LANL data into its evaluation of key fission product yields. The results of the LLNL effort, which includes a preliminary evaluation of the ILRR-LANL data, have been documented. (3) LANL has also conducted an evaluation of fission product yields for fission spectrum neutrons on plutonium including a meta-analysis of benchmark data as part of a planned upgrade to the ENDF/B compilation. We found that the approach of using meta-analysis provides valuable additional insight for evaluating the sparse data sets involved in this assessment. (4) Both laboratories have provided convincing evidence for energy dependence in the fission product yield of {sup 147}Nd produced from the bombardment of {sup 239}Pu with fission spectrum neutrons over an incident neutron energy range of 0.2 to 1.9 MeV. (5) Consistent, complete, and explicit treatment of both systematic and statistical uncertainties, including correlations, are critical to the assessment of both the experimental measurements (due to variations between experimental techniques, irradiation conditions, calibration procedures, etc.), and the evaluation of those experiments to extract fundamental nuclear data. A clear example of the importance of uncertainty analysis is in the justification for energy-dependent {sup 147}Nd fission product yield, where the magnitude of the effect is comparable to the uncertainties of the individual fission product yield measurements. Both LANL and LLNL are committed to the inclusion of full uncertainty analysis in their evaluations. (6) The Panel reviewed in detail two methods for determining/evaluating fission product yields from which fission assessments can be made: the K factor method and high-resolution gamma spectroscopy (both described more fully in Sections 3 and 4). The panel concluded that fission product yields, and thus fission assessments, derived using either approach are equally valid, provided that the data were obtained from well understood, direct fission measurements and that the key underlying calibrations and/or data are valid for each technique. (7) The Panel found the process of peer review of the two complementary but independent methods to be an extremely useful exercise. Although work is still ongoing and the numbers presented to the Panel may change slightly, both groups are now in much better agreement on not just one, but four key fission product yields. The groups also have a better appreciation of the strengths and weaknesses of each other's methods.

  12. Chapter 1.19: Cadmium Telluride Photovoltaic Thin Film: CdTe

    SciTech Connect (OSTI)

    Gessert, T. A.

    2012-01-01

    The chapter reviews the history, development, and present processes used to fabricate thin-film, CdTe-based photovoltaic (PV) devices. It is intended for readers who are generally familiar with the operation and material aspects of PV devices but desire a deeper understanding of the process sequences used in CdTe PV technology. The discussion identifies why certain processes may have commercial production advantages and how the various process steps can interact with each other to affect device performance and reliability. The chapter concludes with a discussion of considerations of large-area CdTe PV deployment including issues related to material availability and energy-payback time.

  13. CdTe portfolio offers commercial ready high efficiency solar - Energy

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

    Innovation Portal Find More Like This Return to Search CdTe portfolio offers commercial ready high efficiency solar National Renewable Energy Laboratory Contact NREL About This Technology Publications: PDF Document Publication MktgSummary CdTe.pdf (117 KB) Schematic illustration of a typical CdTe superstrate thin-film PV device. In this design, the layers of the device are deposited onto a glass &quot;superstrate&quot; that allows sunlight to enter. The sunlight passes through the

  14. Resonant Level Enhancement of the Thermoelectric Power of Bi2Te3 with Tin |

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

    Department of Energy Resonant Level Enhancement of the Thermoelectric Power of Bi2Te3 with Tin Resonant Level Enhancement of the Thermoelectric Power of Bi2Te3 with Tin Application to practical p-type thermoelectric tin alloys for heat pumps. PDF icon heremans.pdf More Documents & Publications The tin impurity in Bi0.5Sb1.5Te3 alloys Strategies for High Thermoelectric zT in Bulk Materials Strategies for High Thermoelectric zT in Bulk Materials

  15. Pursuing early discovery in 13-TeV data at CMS | Argonne National

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

    Laboratory Pursuing early discovery in 13-TeV data at CMS March 15, 2016 12:00PM to 1:00PM Presenter James Hirschauer, Fermilab Location Building 362, Room F108 Type Seminar Series HEP Lunch Seminar Abstract: In 2015, the Larlge Hadron Collider (LHC) center-of-mass energy increased from 8 TeV to 13 TeV following a two-year technical stop of the LHC. This energy increase dramatically enhances the potential for discovery of massive new particles at CMS and ATLAS. Of all models predicting new

  16. Efficiency, Cost and Weight Trade-off in TE Power Generation System for

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

    Vehicle Exhaust Applications | Department of Energy Efficiency, Cost and Weight Trade-off in TE Power Generation System for Vehicle Exhaust Applications Efficiency, Cost and Weight Trade-off in TE Power Generation System for Vehicle Exhaust Applications It contains a detailed co-optimization of the thermoelectric module with the heat sink and a study of the tradeoff between the material cost and efficiency for the TE module and the heat sink. An optimum design is found. PDF icon yazawa.pdf

  17. Ultrafast terahertz-induced response of GeSbTe phase-change materials

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect terahertz-induced response of GeSbTe phase-change materials Citation Details In-Document Search Title: Ultrafast terahertz-induced response of GeSbTe phase-change materials The time-resolved ultrafast electric field-driven response of crystalline and amorphous GeSbTe films has been measured all-optically, pumping with single-cycle terahertz pulses as a means of biasing phase-change materials on a sub-picosecond time-scale. Utilizing the near-band-gap

  18. The effect of structural vacancies on the thermoelectric properties of (Cu?Te){sub 1x}(Ga?Te?)x

    SciTech Connect (OSTI)

    Ye, Zuxin; Young Cho, Jung; Tessema, Misle M.; Salvador, James R.; Waldo, Richard A.; Wang, Hsin; Cai, Wei

    2013-05-01

    We have studied the effects of structural vacancies on the thermoelectric properties of the ternary compounds (Cu?Te)1x(Ga?Te?)x (x=0.5, 0.55, 0.571, 0.6, 0.625, 0.667 and 0.75), which are solid solutions found in the pseudo-binary phase diagram for Cu?Te and Ga?Te?, and possesses tunable structural vacancy concentrations. This materials system is not suitable due to the cost and scarcity of the constituent elements, but the vacancy behavior is well understood and will provide a valuable test case for other systems more suitable from the standpoint of cost and abundance of raw materials, which also possesses these vacancy features, but whose structural characterization is lacking at this stage. We find that the nominally defect free phase CuGaTe? possess the highest ZT (ZT=ST/??, where S is the Seebeck coefficient and ? is the electrical resistivity ? is the thermal conductivity and T is the absolute temperature) which approaches 1 at 840 K and seems to continuously increase above this temperature. This result is due to the unexpectedly low thermal conductivity found for this material at high temperature. The low thermal conductivity was caused by strong Umklapp (thermally resistive scattering processes involving three phonons) phonon scattering. We find that due to the coincidentally strong scattering of carriers by the structural defects that higher concentrations of these features lead to poor electrical transport properties and decreased ZT. - Graphical abstract: Thermal conductivity and zT as a function of temperature for a series of compounds of the type (Cu?Te)1x(Ga?Te?)x (x=0.5, 0.55, 0.571, 0.6, 0.625, 0.667 and 0.75). Highlights: All the samples show p-type semiconducting behavior in the temperature dependence of the Seebeck and Hall coefficients. The increased carrier concentration and the introduction of vacancies diminish the carrier mobility and power factor. The low temperature k decreases significantly as the Ga?Te? content increases due to increasing point defects. The highest ZT ~ 1.0 at 840 K among the samples in this study was found in CuGaTe?, which contains no vacancies.

  19. Static electric dipole polarizabilities of An{sup 5+/6+} and AnO{sub 2}{sup +/2+} (An = U, Np, and Pu) ions

    SciTech Connect (OSTI)

    Parmar, Payal E-mail: kipeters@wsu.edu Peterson, Kirk A. E-mail: kipeters@wsu.edu; Clark, Aurora E. E-mail: kipeters@wsu.edu

    2014-12-21

    The parallel components of static electric dipole polarizabilities have been calculated for the lowest lying spin-orbit states of the penta- and hexavalent oxidation states of the actinides (An) U, Np, and Pu, in both their atomic and molecular diyl ion forms (An{sup 5+/6+} and AnO{sub 2}{sup +/2+}) using the numerical finite-field technique within a four-component relativistic framework. The four-component Dirac-Hartree-Fock method formed the reference for MP2 and CCSD(T) calculations, while multireference Fock space coupled-cluster (FSCC), intermediate Hamiltonian Fock space coupled-cluster (IH-FSCC) and Kramers restricted configuration interaction (KRCI) methods were used to incorporate additional electron correlation. It is observed that electron correlation has significant (?5 a.u.{sup 3}) impact upon the parallel component of the polarizabilities of the diyls. To the best of our knowledge, these quantities have not been previously reported and they can serve as reference values in the determination of various electronic and response properties (for example intermolecular forces, optical properties, etc.) relevant to the nuclear fuel cycle and material science applications. The highest quality numbers for the parallel components (?{sub zz}) of the polarizability for the lowest ? levels corresponding to the ground electronic states are (in a.u.{sup 3}) 44.15 and 41.17 for UO{sub 2}{sup +} and UO{sub 2}{sup 2+}, respectively, 45.64 and 41.42 for NpO{sub 2}{sup +} and NpO{sub 2}{sup 2+}, respectively, and 47.15 for the PuO{sub 2}{sup +} ion.

  20. Intrinsic Rashba-like splitting in asymmetric Bi{sub 2}Te{sub 3}/Sb{sub 2}Te{sub 3} heterogeneous topological insulator films

    SciTech Connect (OSTI)

    Liu, Xiaofei; Guo, Wanlin

    2014-08-25

    We show by density functional theory calculations that asymmetric hetero-stacking of Bi{sub 2}Te{sub 3}/Sb{sub 2}Te{sub 3} films can modulate the topological surface states. Due to the structure inversion asymmetry, an intrinsic Rashba-like splitting of the conical surface bands is aroused. While such splitting in homogeneous Bi{sub 2}Te{sub 3}-class topological insulators can be realized in films with more than three quintuple layers under external electric fields, the hetero-stacking breaks the limit of thickness for preserving the topological nature into the thinnest two quintuple layers. These results indicate that the hetero-stacking can serve as an efficient strategy for spin-resolved band engineering of topological insulators.

  1. Shape-controlled narrow-gap SnTe nanostructures: From nanocubes to nanorods and nanowires

    SciTech Connect (OSTI)

    Guo, Shaojun; Andrew F. Fidler; He, Kai; Su, Dong; Chen, Gen; Lin, Qianglu; Pietryga, Jeffrey M.; Klimov, Victor I.

    2015-11-06

    In this study, the rational design and synthesis of narrow-gap colloidal semiconductor nanocrystals (NCs) is an important step toward the next generation of solution-processable photovoltaics, photodetectors, and thermoelectric devices. SnTe NCs are particularly attractive as a Pb-free alternative to NCs of narrow-gap lead chalcogenides. Previous synthetic efforts on SnTe NCs have focused on spherical nanoparticles. Here we report new strategies for synthesis of SnTe NCs with shapes tunable from highly monodisperse nanocubes, to nanorods (NRs) with variable aspect ratios, and finally to long, straight nanowires (NWs). Reaction at high temperature quickly forms thermodynamically favored nanocubes, but low temperatures lead to elongated particles. Transmission electron microscopy studies of reaction products at various stages of the synthesis reveal that the growth and shape-focusing of monodisperse SnTe nanocubes likely involves interparticle ripening, while directional growth of NRs and NWs may be initiated by particle dimerization via oriented attachment.

  2. Atomic-force microscopy and photoluminescence of nanostructured CdTe

    SciTech Connect (OSTI)

    Babentsov, V.; Sizov, F.; Franc, J.; Luchenko, A.; Svezhentsova, E. Tsybrii, Z.

    2013-09-15

    Low-dimensional CdTe nanorods with a diameter of 10-30 nm and a high aspect ratio that reaches 100 are studied. The nanorods are grown by the physical vapor transport method with the use of Bi precipitates on the substrates. In addition, thin films of closely packed CdTe nanorods with the transverse dimensions {approx}(100-200) nm are grown. Atomic-force microscopy shows that the cross sections of all of the nanorods were hexagonally shaped. By photoluminescence measurements, the inference about the wurtzite structure of CdTe is supported, and the structural quality, electron-phonon coupling, and defects are analyzed. On the basis of recent ab initio calculations, the nature of defects responsible for the formation of deep levels in the CdTe layers and bulk crystals are analyzed.

  3. Ultrathin nanosheets of CrSiTe3: A semiconducting two-dimensional...

    Office of Scientific and Technical Information (OSTI)

    In this work we for the first time exfoliate the CrSiTe3, a bulk ferromagnetic semiconductor, to mono- and few-layer 2D crystals onto a SiSiO2 substrate. The Raman spectra show ...

  4. THE EI'IVIRONMENTAL QUALITY COMPANY CORPCl~V\\TE OFFICE

    Office of Environmental Management (EM)

    EI'IVIRONMENTAL QUALITY COMPANY CORPClVTE OFFICE Ill 36255 MICIat:l;1 '1 J.VENIJE WAYNE , IVICHICA148 '184 te800-5925489 tit fax 800-592-5329 February 20, 2013...

  5. V-183: Cisco TelePresence TC and TE Bugs Let Remote Users Deny...

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

    Remote Users Deny Service and Remote Adjacent Authenticated Users Gain Root Shell Access V-183: Cisco TelePresence TC and TE Bugs Let Remote Users Deny Service and Remote Adjacent...

  6. ON THE ENERGY SPECTRA OF GeV/TeV COSMIC RAY LEPTONS (Journal...

    Office of Scientific and Technical Information (OSTI)

    distribution from a simple power law, in the form of an excess around 0.1-1 TeV energies. ... The model presented here assumes a power-law injection of electrons (and protons) by ...

  7. On the Energy Spectra of GeV/TeV Cosmic Ray Leptons (Journal...

    Office of Scientific and Technical Information (OSTI)

    distribution from a simple power-law, in a form of an excess around 0.1 to 1 TeV energies. ... The model presented here assumes a power-law injection of electrons (and protons) by ...

  8. Structural analysis of Cr aggregation in ferromagnetic semiconductor (Zn,Cr)Te

    SciTech Connect (OSTI)

    Kobayashi, H.; Yamawaki, K.; Nishio, Y.; Kanazawa, K.; Kuroda, S.; Mitome, M.; Bando, Y.

    2013-12-04

    The Cr aggregation in a ferromagnetic semiconductor (Zn,Cr)Te was studied by performing precise analyses using TEM and XRD of microscopic structure of the Cr-aggregated regions formed in iodine-doped Zn{sub 1?x}Cr{sub x}Te films with a relatively high Cr composition x ? 0.2. It was found that the Cr-aggregated regions are composed of Cr{sub 1??}Te nanocrystals of the hexagonal structure and these hexagonal precipitates are stacked preferentially on the (111)A plane of the zinc-blende (ZB) structure of the host ZnTe crystal with its c-axis nearly parallel to the (111){sub ZB} plane.

  9. Measuring the Invisible Higgs Width at the 7 and 8 TeV LHC (Journal...

    Office of Scientific and Technical Information (OSTI)

    Higgs Width at the 7 and 8 TeV LHC Authors: Bai, Yang ; SLAC ; Draper, Patrick ; UC, Santa Cruz ; Shelton, Jessie ; Yale U. ; , Publication Date: 2013-10-25 OSTI Identifier:...

  10. Thermoelectric properties of AgSbTe? from first-principles calculations

    SciTech Connect (OSTI)

    Rezaei, Nafiseh; Akbarzadeh, Hadi; Hashemifar, S. Javad

    2014-09-14

    The structural, electronic, and transport properties of AgSbTe? are studied by using full-relativistic first-principles electronic structure calculation and semiclassical description of transport parameters. The results indicate that, within various exchange-correlation functionals, the cubic Fd3?m and trigonal R3?m structures of AgSbTe? are more stable than two other considered structures. The computed Seebeck coefficients at different values of the band gap and carrier concentration are accurately compared with the available experimental data to speculate a band gap of about 0.10.35 eV for AgSbTe? compound, in agreement with our calculated electronic structure within the hybrid HSE (Heyd-Scuseria-Ernzerhof) functional. By calculating the semiclassical Seebeck coefficient, electrical conductivity, and electronic part of thermal conductivity, we present the theoretical upper limit of the thermoelectric figure of merit of AgSbTe? as a function of temperature and carrier concentration.

  11. Deformation and shape transitions in hot rotating neutron deficient Te isotopes

    SciTech Connect (OSTI)

    Aggarwal, Mamta; Mazumdar, I.

    2009-08-15

    Evolution of the nuclear shapes and deformations under the influence of temperature and rotation is investigated in Te isotopes with neutron number ranging from the proton drip line to the stability valley. Spin dependent critical temperatures for the shape transitions in Te nuclei are computed. Shape transitions from prolate at low temperature and spin to oblate via triaxiality are seen with increasing neutron number and spin.

  12. NuTeV Anomaly Helps Shed Light on Physics of the Nucleus | Jefferson Lab

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

    NuTeV Anomaly Helps Shed Light on Physics of the Nucleus NEWPORT NEWS, VA, June 29, 2009 - A new calculation clarifies the complicated relationship between protons and neutrons in the atomic nucleus and offers a fascinating resolution of the famous NuTeV Anomaly. The calculation, published in the journal Physical Review Letters on June 26, was carried out by a collaboration of researchers from the Department of Energy's Thomas Jefferson National Accelerator Facility, Tokai University and the

  13. Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials Citation Details In-Document Search Title: Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials Authors: Shu, Michael J. ; Zalden, Peter ; Chen, Frank ; Weems, Ben ; Chatzakis, Ioannis ; Xiong, Feng ; Jeyasingh, Rakesh ; Hoffmann, Matthias C. ; Pop, Eric ; Wong, H.-S.Philip ; Wuttig, Matthias ; Lindenberg, Aaron M. Publication Date: 2014-07-08 OSTI

  14. Ultrathin nanosheets of CrSiTe3: A semiconducting two-dimensional

    Office of Scientific and Technical Information (OSTI)

    ferromagnetic material (Journal Article) | SciTech Connect Ultrathin nanosheets of CrSiTe3: A semiconducting two-dimensional ferromagnetic material Citation Details In-Document Search This content will become publicly available on November 27, 2016 Title: Ultrathin nanosheets of CrSiTe3: A semiconducting two-dimensional ferromagnetic material Finite range ferromagnetism and antiferromagnetism in two-dimensional (2D) systems within an isotropic Heisenberg model at non-zero temperature were

  15. Diluted magnetic semiconductors based on Sb2-xVxTe3 | Energy Frontier

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

    Research Centers Diluted magnetic semiconductors based on Sb2-xVxTe3 Home Author: J. S. Dyck, P. Hajek, P. Lostak, C. Uher Year: 2002 Abstract: We report on a diluted magnetic semiconductor based on the Sb2Te3 tetradymite structure doped with very low concentrations of vanadium (1-3 at. %). The anomalous transport behavior and robust magnetic hysteresis loops observed in magnetotransport and magnetic measurements are experimental manifestations of the ferromagnetic state in these materials.

  16. Spin glass in semiconducting KFe1.05Ag0.88Te2 single crystals

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

    Ryu, H.; Lei, H.; Klobes, B.; Warren, J. B.; Hermann, R. P.; Petrovic, C.

    2015-05-26

    We report discovery of KFe1.05Ag0.88Te2 single crystals with semiconducting spin glass ground state. Composition and structure analysis suggest nearly stoichiometric I4/mmm space group but allow for the existence of vacancies, absent in long range semiconducting antiferromagnet KFe1.05Ag0.88Te2. The subtle change in stoichometry in Fe/Ag sublattice changes magnetic ground state but not conductivity, giving further insight into the semiconducting gap mechanism.

  17. Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Terahertz-Induced Response of GeSbTe Phase-Change Materials Citation Details In-Document Search Title: Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials Authors: Shu, Michael J. ; Zalden, Peter ; Chen, Frank ; Weems, Ben ; Chatzakis, Ioannis ; Xiong, Feng ; Jeyasingh, Rakesh ; Hoffmann, Matthias C. ; Pop, Eric ; Wong, H.-S.Philip ; Wuttig, Matthias ; Lindenberg, Aaron M. Publication Date: 2014-07-08 OSTI Identifier: 1136695 Report

  18. Ion-beam treatment to prepare surfaces of p-CdTe films

    DOE Patents [OSTI]

    Gessert, Timothy A. (Conifer, CO)

    2001-01-01

    A method of making a low-resistance electrical contact between a p-CdTe layer and outer contact layers by ion beam processing comprising: a) placing a CdS/CdTe device into a chamber and evacuating the chamber; b) orienting the p-CdTe side of the CdS/CdTe layer so that it faces apparatus capable of generating Ar atoms and ions of preferred energy and directionality; c) introducing Ar and igniting the area of apparatus capable of generating Ar atoms and ions of preferred energy and directionality in a manner so that during ion exposure, the source-to-substrate distance is maintained such that it is less than the mean-free path or diffusion length of the Ar atoms and ions at the vacuum pressure; d) allowing exposure of the p-CdTe side of the device to said ion beam for a period less than about 5 minutes; and e) imparting movement to the substrate to control the real uniformity of the ion-beam exposure on the p-CdTe side of the device.

  19. Oxygen Incorporation During Fabrication of Substrate CdTe Photovoltaic Devices: Preprint

    SciTech Connect (OSTI)

    Duenow, J. N.; Dhere, R. G.; Kuciauskas, D.; Li, J. V.; Pankow, J. W.; DeHart, C. M.; Gessert, T. A.

    2012-06-01

    Recently, CdTe photovoltaic (PV) devices fabricated in the nonstandard substrate configuration have attracted increasing interest because of their potential compatibility with flexible substrates such as metal foils and polymer films. This compatibility could lead to the suitability of CdTe for roll-to-roll processing and building-integrated PV. Currently, however, the efficiencies of substrate CdTe devices reported in the literature are significantly lower ({approx}6%-8%) than those of high-performance superstrate devices ({approx}17%) because of significantly lower open-circuit voltage (Voc) and fill factor (FF). In our recent device development efforts, we have found that processing parameters required to fabricate high-efficiency substrate CdTe PV devices differ from those necessary for traditional superstrate CdTe devices. Here, we investigate how oxygen incorporation in the CdTe deposition, CdCl2 heat treatment, CdS deposition, and post-deposition heat treatment affect device characteristics through their effects on the junction. By adjusting whether oxygen is incorporated during these processing steps, we have achieved Voc values greater than 860 mV and efficiencies greater than 10%.

  20. Ultrathin nanosheets of CrSiTe3: A semiconducting two-dimensional ferromagnetic material

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

    Lin, Ming -Wei; Zhung, Houlong L.; Yan, Jiaqiang; Ward, Thomas Zac; Puretzky, Alexander A.; Rouleau, Christopher M.; Gai, Zheng; Liang, Liangbo; Meunier, Vincent; Ganesh, Panchapakesan; et al

    2015-11-27

    Finite range ferromagnetism and antiferromagnetism in two-dimensional (2D) systems within an isotropic Heisenberg model at non-zero temperature were originally proposed to be impossible. However, recent theoretical studies using an Ising model have recently shown that 2D magnetic crystals can exhibit magnetism. Experimental verification of existing 2D magnetic crystals in this system has remained elusive. In this work we for the first time exfoliate the CrSiTe3, a bulk ferromagnetic semiconductor, to mono- and few-layer 2D crystals onto a Si/SiO2 substrate. The Raman spectra show the good stability and high quality of the exfoliated flakes, consistent with the computed phonon spectra ofmore » 2D CrSiTe3, giving a strong evidence for the existence of 2D CrSiTe3 crystals. When the thickness of the CrSiTe3 crystals is reduced to few-layers, we observed a clear change in resistivity at 80~120 K, consistent with the theoretical calculations on the Curie temperature (Tc) of ~80 K for the magnetic ordering of 2D CrSiTe3 crystals. As a result, the ferromagnetic mono- and few-layer 2D CrSiTe3 indicated here should enable numerous applications in nano-spintronics.« less

  1. Enhanced thermoelectric performance in Cd doped CuInTe{sub 2} compounds

    SciTech Connect (OSTI)

    Cheng, N.; Liu, R.; Bai, S.; Shi, X. Chen, L.

    2014-04-28

    CuIn{sub 1?x}Cd{sub x}Te{sub 2} materials (x?=?0, 0.02, 0.05, and 0.1) are prepared using melting-annealing method and the highly densified bulk samples are obtained through Spark Plasma Sintering. The X-ray diffraction data confirm that nearly pure chalcopyrite structures are obtained in all the samples. Due to the substitution of Cd at In sites, the carrier concentration is greatly increased, leading to much enhanced electrical conductivity and power factor. The single parabolic band model is used to describe the electrical transport properties of CuInTe{sub 2} and the low temperature Hall mobility is also modeled. By combing theoretical model and experiment data, the optimum carrier concentration in CuInTe{sub 2} is proposed to explain the greatly enhanced power factors in the Cd doped CuInTe{sub 2}. In addition, the thermal conductivity is reduced by extra phonon scattering due to the atomic mass and radius fluctuations between Cd and In atoms. The maximum zTs are observed in CuIn{sub 0.98}Cd{sub 0.02}Te{sub 2} and CuIn{sub 0.9}Cd{sub 0.1}Te{sub 2} samples, which are improved by over 100% at room temperature and around 20% at 600?K.

  2. DEGREE-SCALE GeV 'JETS' FROM ACTIVE AND DEAD TeV BLAZARS

    SciTech Connect (OSTI)

    Neronov, A.; Semikoz, D.; Kachelriess, M.; Ostapchenko, S.; Elyiv, A.

    2010-08-20

    We show that images of TeV blazars in the GeV energy band should contain, along with point-like sources, degree-scale jet-like extensions. These GeV extensions are the result of electromagnetic cascades initiated by TeV {gamma}-rays interacting with extragalactic background light and the deflection of the cascade electrons/positrons in extragalactic magnetic fields (EGMFs). Using Monte Carlo simulations, we study the spectral and timing properties of the degree-scale extensions in simulated GeV band images of TeV blazars. We show that the brightness profile of such degree-scale extensions can be used to infer the light curve of the primary TeV {gamma}-ray source over the past 10{sup 7} yr, i.e., over a time scale comparable to the lifetime of the parent active galactic nucleus. This implies that the degree-scale jet-like GeV emission could be detected not only near known active TeV blazars, but also from 'TeV blazar remnants', whose central engines were switched off up to 10 million years ago. Since the brightness profile of the GeV 'jets' depends on the strength and the structure of the EGMF, their observation provides additional information about the EGMF.

  3. Structural characterization of Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} as a function of temperature using neutron powder diffraction and extended X-ray absorption fine structure techniques

    SciTech Connect (OSTI)

    Mansour, A. N.; Wong-Ng, W.; Huang, Q.; Tang, W.; Thompson, A.; Sharp, J.

    2014-08-28

    The structure of Bi{sub 2}Te{sub 3} (Seebeck coefficient Standard Reference Material (SRM 3451)) and the related phase Sb{sub 2}Te{sub 3} have been characterized as a function of temperature using the neutron powder diffraction (NPD) and the extended X-ray absorption fine structure (EXAFS) techniques. The neutron structural studies were carried out from 20?K to 300?K for Bi{sub 2}Te{sub 3} and from 10?K to 298?K for Sb{sub 2}Te{sub 3}. The EXAFS technique for studying the local structure of the two compounds was conducted from 19?K to 298?K. Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} are isostructural, with a space group of R3{sup }m. The structure consists of repeated quintuple layers of atoms, Te2-M-Te1-M-Te2 (where M?=?Bi or Sb) stacking along the c-axis of the unit cell. EXAFS was used to examine the bond distances and static and thermal disorders for the first three shells of Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} as a function of temperature. The temperature dependencies of thermal disorders were analyzed using the Debye and Einstein models for lattice vibrations. The Debye and Einstein temperatures for the first two shells of Bi{sub 2}Te{sub 3} are similar to those of Sb{sub 2}Te{sub 3} within the uncertainty in the data. However, the Debye and Einstein temperatures for the third shell of Bi-Bi are significantly lower than those of the third shell of Sb-Sb. The Einstein temperature for the third shell is consistent with a soft phonon mode in both Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3}. The lower Einstein temperature of Bi-Bi relative to Sb-Sb is consistent with the lower value of thermal conductivity of Bi{sub 2}Te{sub 3} relative to Sb{sub 2}Te{sub 3}.

  4. PbTe/TAGS RTG Mars Environmental Survey (MESUR) mission

    SciTech Connect (OSTI)

    Schock, A. )

    1993-01-10

    The paper describes the results of studies on an RTG option for powering the global network of unmanned landers for NASA's Mars Environmental Survey (MESUR) mission. RTGs are essentially unaffected by diurnal and seasonal variations, Martian sandstorms, and landing site latitudes, and their waste heat can stabilize the temperatures of the landers and their payload. The RTG designs described in this paper are based on PbTe/TAGS thermoelectric elements, in contast to the SiGe-based RTGs the author described in previous publications. The presently described RTGs differ not only in the choice of thermoelectric materials but also in the use of much lower operating temperatures, conductive rather than radiative heat transfer, an inert cover gas instead of vacuum in the RTG's converter, and fibrous instead of multifoil thermal insulation. As in a previous Teledyne design, the Fairchild designs described in this paper employ flight-proven General Purpose Source modules and Close-Pack Arrays of thermoelectric converter modules. Illustrative point designs of RTGs producing 41 and 51 watts(e) at 28 volts are presented. The presented performance parameters were derived by detailed thermal, thermoelectric, and electrical analyses (including radiator geometry optimization) described in the paper. The Fairchild study showed that, with appropriate modifications, the Teledyne design can be scaled up to higher power levels, and it identified solutions to ensure adequate fuel clad ductility at launch temperatures and adequate thermal conductance from the thermoelectric cold ends to the RTG housing.

  5. First-epoch VLBA imaging of 20 new TeV blazars

    SciTech Connect (OSTI)

    Piner, B. Glenn; Edwards, Philip G.

    2014-12-10

    We present Very Long Baseline Array (VLBA) images of 20 TeV blazars not previously well studied on the parsec scale. All 20 of these sources are high-frequency peaked BL Lac objects (HBLs). Observations were made between August and December of 2013 at a frequency of 8.4 GHz. These observations represent the first epoch of a VLBA monitoring campaign on these blazars, and they significantly increase the fraction of TeV HBLs studied with high-resolution imaging. The peak very long baseline interferometry (VLBI) flux densities of these sources range from ?10 to ?100 mJy bm{sup 1}, and parsec-scale jet structure is detected in all sources. About half of the VLBI cores are resolved, with brightness temperature upper limits of a few times 10{sup 10} K, and we find that a brightness temperature of ?2 10{sup 10} K is consistent with the VLBI data for all but one of the sources. Such brightness temperatures do not require any relativistic beaming to reduce the observed value below commonly invoked intrinsic limits; however, the lack of detection of counterjets does place a modest limit on the bulk Lorentz factor of ? ? 2. These data are thus consistent with a picture where weak-jet sources like the TeV HBLs develop significant velocity structures on parsec scales. We also extend consideration to the full sample of TeV HBLs by combining the new VLBI data with VLBI and gamma-ray data from the literature. By comparing measured VLBI and TeV fluxes to samples with intrinsically uncorrelated luminosities generated by Monte Carlo simulations, we find a marginally significant correlation between the VLBI and TeV fluxes for the full TeV HBL sample.

  6. Development of a Total Energy, Environment and Asset Management (TE2AM tm) Curriculum

    SciTech Connect (OSTI)

    2012-12-31

    The University of Wisconsin Department of Engineering Professional Development (EPD) has completed the sponsored project entitled, Development of a Total Energy, Environment and Asset Management (TE2AM) Curriculum. The project involved the development of a structured professional development program to improve the knowledge, skills, capabilities, and competencies of engineers and operators of commercial buildings. TE2AM advances a radically different approach to commercial building design, operation, maintenance, and end-?of-?life disposition. By employing asset management principles to the lifecycle of a commercial building, owners and occupants will realize improved building performance, reduced energy consumption and positive environmental impacts. Through our commercialization plan, we intend to offer TE2AM courses and certificates to the professional community and continuously improve TE2AM course materials. The TE2AM project supports the DOE Strategic Theme 1 -? Energy Security; and will further advance the DOE Strategic Goal 1.4 Energy Productivity. Through participation in the TE2AM curriculum, engineers and operators of commercial buildings will be eligible for a professional certificate; denoting the completion of a prescribed series of learning activities. The project involved a comprehensive, rigorous approach to curriculum development, and accomplished the following goals: 1. Identify, analyze and prioritize key learning needs of engineers, architects and technical professionals as operators of commercial buildings. 2. Design and develop TE2AM curricula and instructional strategies to meet learning needs of the target learning community. 3. Establish partnerships with the sponsor and key stakeholders to enhance the development and delivery of learning programs. 4. Successfully commercialize and sustain the training and certificate programs for a substantial time following the term of the award. The project team was successful in achieving the goals and deliverables set forth in the original proposal. Though attempts were made to adhere to the original project timeline, the team requested, and was granted a 6-?month project extension, during which time the project was completed.

  7. Electronic inhomogeneity and Ag:Sb imbalance of Ag1-yPb18Sb1+zTe20

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

    high-performance thermoelectrics elucidated by 125Te and 207Pb NMR | Energy Frontier Research Centers Electronic inhomogeneity and Ag:Sb imbalance of Ag1-yPb18Sb1+zTe20 high-performance thermoelectrics elucidated by 125Te and 207Pb NMR Home Author: E.M. Levin, B.A. Cook, K. Ahn, M.G. Kanatzidis, K. Schmidt-Rohr Year: 2009 Abstract: Using magic-angle spinning 125Te and 207Pb NMR, we have discovered the presence of two phases of approximately tenfold different free-electron concentration, n,

  8. The tin impurity in Bi0.5Sb1.5Te3 alloys | Department of Energy

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

    The tin impurity in Bi0.5Sb1.5Te3 alloys The tin impurity in Bi0.5Sb1.5Te3 alloys Extends work on tin to p-type thermoelectric alloys of formula Bi(2-x)Sb(x)Te(3) doped with Sn. Both single crystals and polycrystals prepared using powder metallurgical techniques are studied and properties reported. PDF icon jaworski.pdf More Documents & Publications Resonant Level Enhancement of the Thermoelectric Power of Bi2Te3 with Tin DOE/NSF Thermoelectric Partnership Project SEEBECK Saving Energy

  9. Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on {sup 239}Pu, {sup 235}U, {sup 238}U

    SciTech Connect (OSTI)

    Selby, H.D.; Mac Innes, M.R.; Barr, D.W.; Keksis, A.L.; Meade, R.A.; Burns, C.J.; Chadwick, M.B.; Wallstrom, T.C.

    2010-12-15

    We describe measurements of fission product data at Los Alamos that are important for determining the number of fissions that have occurred when neutrons are incident on plutonium and uranium isotopes. The fission-spectrum measurements were made using a fission chamber designed by the National Institute for Standards and Technology (NIST) in the BIG TEN critical assembly, as part of the Inter-laboratory Liquid Metal Fast Breeder Reactor (LMFBR) Reaction Rate (ILRR) collaboration. The thermal measurements were made at Los Alamos' Omega West Reactor. A related set of measurements were made of fission-product ratios (so-called R-values) in neutron environments provided by a number of Los Alamos critical assemblies that range from having average energies causing fission of 400-600 keV (BIG TEN and the outer regions of the Flattop-25 assembly) to higher energies (1.4-1.9 MeV) in the Jezebel, and in the central regions of the Flattop-25 and Flattop-Pu, critical assemblies. From these data we determine ratios of fission product yields in different fuel and neutron environments (Q-values) and fission product yields in fission spectrum neutron environments for {sup 99}Mo, {sup 95}Zr, {sup 137}Cs, {sup 140}Ba, {sup 141,143}Ce, and {sup 147}Nd. Modest incident-energy dependence exists for the {sup 147}Nd fission product yield; this is discussed in the context of models for fission that include thermal and dynamical effects. The fission product data agree with measurements by Maeck and other authors using mass-spectrometry methods, and with the ILRR collaboration results that used gamma spectroscopy for quantifying fission products. We note that the measurements also contradict earlier 1950s historical Los Alamos estimates by {approx}5-7%, most likely owing to self-shielding corrections not made in the early thermal measurements. Our experimental results provide a confirmation of the England-Rider ENDF/B-VI evaluated fission-spectrum fission product yields that were carried over to the ENDF/B-VII.0 library, except for {sup 99}Mo where the present results are about 4%-relative higher for neutrons incident on {sup 239}Pu and {sup 235}U. Additionally, our results illustrate the importance of representing the incident energy dependence of fission product yields over the fast neutron energy range for high-accuracy work, for example the {sup 147}Nd from neutron reactions on plutonium. An upgrade to the ENDF library, for ENDF/B-VII.1, based on these and other data, is described in a companion paper to this work.

  10. Static atomic displacements in a CdTe epitaxial layer on a GaAs substrate

    SciTech Connect (OSTI)

    Horning, R.D.; Staudenmann, J.

    1987-05-25

    A (001)CdTe epitaxial layer on a (001)GaAs substrate was studied by x-ray diffraction between 10 and 360 K. The CdTe growth took place at 380 /sup 0/C in a vertical gas flow metalorganic chemical vapor deposition reactor. Lattice parameters and integrated intensities of both the substrate and the epitaxial layer using the (00l) and (hhh) Bragg reflections reveal three important features. Firstly, the GaAs substrate does not exhibit severe strain after deposition and it is as perfect as a bulk GaAs. Secondly, the CdTe unit cell distorts tetragonally with a/sub perpendicular/>a/sub parallel/ below 300 K. The decay of the (00l) reflection intensities as a function of the temperature yields a Debye temperature of 142 K, the same value as for bulk CdTe. Thirdly, a temperature-dependent isotropic static displacement of the Cd and the Te atoms is introduced to account for the anomalous behavior of the (hhh) intensities.

  11. Reduction of Fermi level pinning and recombination at polycrystalline CdTe surfaces by laser irradiation

    SciTech Connect (OSTI)

    Simonds, Brian J.; Kheraj, Vipul; Palekis, Vasilios; Ferekides, Christos; Scarpulla, Michael A.

    2015-06-14

    Laser processing of polycrystalline CdTe is a promising approach that could potentially increase module manufacturing throughput while reducing capital expenditure costs. For these benefits to be realized, the basic effects of laser irradiation on CdTe must be ascertained. In this study, we utilize surface photovoltage spectroscopy (SPS) to investigate the changes to the electronic properties of the surface of polycrystalline CdTe solar cell stacks induced by continuous-wave laser annealing. The experimental data explained within a model consisting of two space charge regions, one at the CdTe/air interface and one at the CdTe/CdS junction, are used to interpret our SPS results. The frequency dependence and phase spectra of the SPS signal are also discussed. To support the SPS findings, low-temperature spectrally-resolved photoluminescence and time-resolved photoluminescence were also measured. The data show that a modest laser treatment of 250?W/cm{sup 2} with a dwell time of 20?s is sufficient to reduce the effects of Fermi level pinning at the surface due to surface defects.

  12. An Experiment to Locate the Site of TeV Flaring in M87

    SciTech Connect (OSTI)

    Harris, D.E.; /Harvard-Smithsonian Ctr. Astrophys.; Massaro, F.; /Harvard-Smithsonian Ctr. Astrophys. /KIPAC, Menlo Park /SLAC; Cheung, C.C.; /Natl. Acad. Sci. /Naval Research Lab, Wash., D.C.; Horns, D.; Raue, M.; /Hamburg U.; Stawarz, L.; /JAXA, Sagamihara /Jagiellonian U., Astron. Observ.; Wagner, S.; /Heidelberg Observ.; Colin, P.; /Munich, Max Planck Inst.; Mazin, D.; /Barcelona, IFAE; Wagner, R.; /Munich, Max Planck Inst.; Beilicke, M.; /McDonnell Ctr. Space Sci.; LeBohec, S.; Hui, M.; /Utah U.; Mukherjee, R.; /Barnard Coll.

    2012-05-18

    We describe a Chandra X-ray target-of-opportunity project designed to isolate the site of TeV flaring in the radio galaxy M87. To date, we have triggered the Chandra observations only once (2010 April) and by the time of the first of our nine observations, the TeV flare had ended. However, we found that the X-ray intensity of the unresolved nucleus was at an elevated level for our first observation. Of the more than 60 Chandra observations we have made of the M87 jet covering nine years, the nucleus was measured at a comparably high level only three times. Two of these occasions can be associated with TeV flaring, and at the time of the third event, there were no TeV monitoring activities. From the rapidity of the intensity drop of the nucleus, we infer that the size of the emitting region is of order a few light days x the unknown beaming factor; comparable to the same sort of estimate for the TeV emitting region. We also find evidence of spectral evolution in the X-ray band which seems consistent with radiative losses affecting the non-thermal population of the emitting electrons within the unresolved nucleus.

  13. Synthesis, crystal and electronic structure, and physical properties of the new lanthanum copper telluride La{sub 3}Cu{sub 5}Te{sub 7}

    SciTech Connect (OSTI)

    Zelinska, Mariya; Assoud, Abdeljalil [Department of Chemistry, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada); Kleinke, Holger, E-mail: kleinke@uwaterloo.c [Department of Chemistry, University of Waterloo, Waterloo, ON, Canada N2L 3G1 (Canada)

    2011-03-15

    The new lanthanum copper telluride La{sub 3}Cu{sub 5-x}Te{sub 7} has been obtained by annealing the elements at 1073 K. Single-crystal X-ray diffraction studies revealed that the title compound crystallizes in a new structure type, space group Pnma (no. 62) with lattice dimensions of a=8.2326(3) A, b=25.9466(9) A, c=7.3402(3) A, V=1567.9(1) A{sup 3}, Z=4 for La{sub 3}Cu{sub 4.86(4)}Te{sub 7}. The structure of La{sub 3}Cu{sub 5-x}Te{sub 7} is remarkably complex. The Cu and Te atoms build up a three-dimensional covalent network. The coordination polyhedra include trigonal LaTe{sub 6} prisms, capped trigonal LaTe{sub 7} prisms, CuTe{sub 4} tetrahedra, and CuTe{sub 3} pyramids. All Cu sites exhibit deficiencies of various extents. Electrical property measurements on a sintered pellet of La{sub 3}Cu{sub 4.86}Te{sub 7} indicate that it is a p-type semiconductor in accordance with the electronic structure calculations. -- Graphical abstract: Oligomeric unit comprising interconnected CuTe{sub 3} pyramids and CuTe{sub 4} tetrahedra. Display Omitted Research highlights: {yields} La{sub 3}Cu{sub 5-x}Te{sub 7} adopts a new structure type. {yields} All Cu sites exhibit deficiencies of various extents. {yields} The coordination polyhedra include trigonal LaTe{sub 6} prisms, capped trigonal LaTe{sub 7} prisms, CuTe{sub 4} tetrahedra and CuTe{sub 3} pyramids. {yields} La{sub 3}Cu{sub 5-x}Te{sub 7} is a p-type semiconductor.

  14. /sup 235/U(n,f), /sup 238/U(n,gamma), /sup 238/U(n,f) and /sup 239/Pu(n,f) reaction rate measurement calibrations at ZPPR

    SciTech Connect (OSTI)

    Poenitz, W.P.; Maddison, D.W.; Gasidlo, J.M.; Carpenter, S.G.; Armani, R.J.

    1987-01-01

    New reference deposits for /sup 235/U, /sup 239/Pu and /sup 238/U have been established with mass uncertainties of <0.2%. These new deposits replace the older reference deposits which were used during the last 17 years and improve the uncertainty of reaction rate measurements due to reference mass uncertainties by about a factor of 6. Measurements of the fission fragment absorption in 2..pi.. and low-geometry count rates. Two measurements of the /sup 238/U capture rate in depleted uranium samples based upon the thermal cross sections of /sup 238/U(n,..gamma..), /sup 235/U(n,f) and /sup 239/Pu(n,f) and based upon the /sup 243/Am calibration technique confirm the ZPPR measurement technique within the quoted uncertainty of +-0.5%.

  15. Systematic study of doping dependence on linear magnetoresistance in p-PbTe

    SciTech Connect (OSTI)

    Schneider, J. M.; Chitta, V. A.; Oliveira, N. F.; Peres, M. L. Castro, S. de; Soares, D. A. W.; Wiedmann, S.; Zeitler, U.; Abramof, E.; Rappl, P. H. O.; Mengui, U. A.

    2014-10-20

    We report on a large linear magnetoresistance effect observed in doped p-PbTe films. While undoped p-PbTe reveals a sublinear magnetoresistance, p-PbTe films doped with BaF{sub 2} exhibit a transition to a nearly perfect linear magnetoresistance behaviour that is persistent up to 30?T. The linear magnetoresistance slope ?R/?B is to a good approximation, independent of temperature. This is in agreement with the theory of Quantum Linear Magnetoresistance. We also performed magnetoresistance simulations using a classical model of linear magnetoresistance. We found that this model fails to explain the experimental data. A systematic study of the doping dependence reveals that the linear magnetoresistance response has a maximum for small BaF{sub 2} doping levels and diminishes rapidly for increasing doping levels. Exploiting the huge impact of doping on the linear magnetoresistance signal could lead to new classes of devices with giant magnetoresistance behavior.

  16. Ba{sub 2}TeO as an optoelectronic material: First-principles study

    SciTech Connect (OSTI)

    Sun, Jifeng; Shi, Hongliang; Du, Mao-Hua; Singh, David J.; Siegrist, Theo

    2015-05-21

    The band structure, optical, and defects properties of Ba{sub 2}TeO are systematically investigated using density functional theory with a view to understanding its potential as an optoelectronic or transparent conducting material. Ba{sub 2}TeO crystallizes with tetragonal structure (space group P4/nmm) and with a 2.93?eV optical bandgap [Besara et al., J. Solid State Chem. 222, 60 (2015)]. We find relatively modest band masses for both electrons and holes suggesting applications. Optical properties show infrared-red absorption when doped. This could potentially be useful for combining wavelength filtering and transparent conducting functions. Furthermore, our defect calculations show that Ba{sub 2}TeO is intrinsically p-type conducting under Ba-poor condition. However, the spontaneous formation of the donor defects may constrain the p-type transport properties and would need to be addressed to enable applications.

  17. Pair correlations in neutrinoless double {beta} decay candidate {sup 130}Te.

    SciTech Connect (OSTI)

    Bloxham, T.; Kay, B. P.; Schiffer, J. P.; Clark, J. A.; Deibel, C. M.; Freeman, S. J.; Freedman, S. J.; Howard, A. M.; McAllister, S. A.; Parker, P. D.; Sharp, D. K.; Thomas, J. S. (Physics); ( PSC-USR); (LBNL); (Michigan State Univ.); (Univ. of Manchester); (Yale Univ.)

    2010-08-16

    Pair correlations in the ground state of {sup 130}Te have been investigated using pair-transfer experiments to explore the validity of approximations in calculating the matrix element for neutrinoless double-{beta} decay. This nucleus is a candidate for the observation of such decay, and a good understanding of its structure is crucial for eventual calculations of the neutrino mass, should such a decay indeed be observed. For proton-pair adding, strong transitions to excited 0{sup +} states had been observed in the Te isotopes by Alford et al. [Nucl. Phys. A 323, 339 (1979)], indicating a breaking of the BCS approximation for protons in the ground state. We measured the neutron-pair removing (p,t) reaction on {sup 130}Te and found no indication of a corresponding splitting of the BCS nature of the ground state for neutrons.

  18. Pair correlations in the neutrinoless double-{beta} decay candidate {sup 130}Te

    SciTech Connect (OSTI)

    Bloxham, T.; Freedman, S. J. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Kay, B. P.; Schiffer, J. P.; Clark, J. A. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Deibel, C. M. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48825 (United States); Freeman, S. J.; Howard, A. M.; McAllister, S. A.; Sharp, D. K.; Thomas, J. S. [Schuster Laboratory, University of Manchester, Manchester, M13 9PL (United Kingdom); Parker, P. D. [A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States)

    2010-08-15

    Pair correlations in the ground state of {sup 130}Te have been investigated using pair-transfer experiments to explore the validity of approximations in calculating the matrix element for neutrinoless double-{beta} decay. This nucleus is a candidate for the observation of such decay, and a good understanding of its structure is crucial for eventual calculations of the neutrino mass, should such a decay indeed be observed. For proton-pair adding, strong transitions to excited 0{sup +} states had been observed in the Te isotopes by Alford et al. [Nucl. Phys. A 323, 339 (1979)], indicating a breaking of the BCS approximation for protons in the ground state. We measured the neutron-pair removing (p,t) reaction on {sup 130}Te and found no indication of a corresponding splitting of the BCS nature of the ground state for neutrons.

  19. Superconducting thin films of (100) and (111) oriented indium doped topological crystalline insulator SnTe

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

    Si, W.; Zhang, C.; Wu, L.; Ozaki, T.; Gu, G.; Li, Q.

    2015-09-01

    Recent discovery of the topological crystalline insulator SnTe has triggered a search for topological superconductors, which have potential application to topological quantum computing. The present work reports on the superconducting properties of indium doped SnTe thin films. The (100) and (111) oriented thin films were epitaxially grown by pulsed-laser deposition on (100) and (111) BaF2 crystalline substrates respectively. The onset superconducting transition temperatures are about 3.8 K for (100) and 3.6 K for (111) orientations, slightly lower than that of the bulk. Magneto-resistive measurements indicate that these thin films may have upper critical fields higher than that of the bulk.more » With large surface-to-bulk ratio, superconducting indium doped SnTe thin films provide a rich platform for the study of topological superconductivity and potential device applications based on topological superconductors.« less

  20. Simulation of Electric Field in Semi Insulating Au/CdTe/Au Detector under Flux

    SciTech Connect (OSTI)

    Franc, J.; James, R.; Grill, R.; Kubat, J.; Belas, E.; Hoschl, P.; Moravec, P.; Praus, P.

    2009-08-02

    We report our simulations on the profile of the electric field in semi insulating CdTe and CdZnTe with Au contacts under radiation flux. The type of the space charge and electric field distribution in the Au/CdTe/Au structure is at high fluxes result of a combined influence of charge formed due to band bending at the electrodes and from photo generated carriers, which are trapped at deep levels. Simultaneous solution of drift-diffusion and Poisson equations is used for the calculation. We show, that the space charge originating from trapped photo-carriers starts to dominate at fluxes 10{sup 15}-10{sup 16}cm{sup -2}s{sup -1}, when the influence of contacts starts to be negligible.

  1. Experimental Realization of a Three-Dimensional Topological Insulator, Bi 2Te3

    SciTech Connect (OSTI)

    Siemons, W.

    2010-02-24

    Three-dimensional topological insulators are a new state of quantum matter with a bulk gap and odd number of relativistic Dirac fermions on the surface. By investigating the surface state of Bi{sub 2}Te{sub 3} with angle-resolved photoemission spectroscopy, we demonstrate that the surface state consists of a single nondegenerate Dirac cone. Furthermore, with appropriate hole doping, the Fermi level can be tuned to intersect only the surface states, indicating a full energy gap for the bulk states. Our results establish that Bi{sub 2}Te{sub 3} is a simple model system for the three-dimensional topological insulator with a single Dirac cone on the surface. The large bulk gap of Bi{sub 2}Te{sub 3} also points to promising potential for high-temperature spintronics applications.

  2. Role of polycrystallinity in CdTe and CuInSe sub 2 photovoltaic cells

    SciTech Connect (OSTI)

    Sites, J.R. )

    1991-01-01

    The polycrystalline nature of thin-film CdTe and CuInSe{sub 2} solar cells continues to be a major factor in several individual losses that limit overall cell efficiency. This report describes progress in the quantitative separation of these losses, including both measurement and analysis procedures. It also applies these techniques to several individual cells to help document the overall progress with CdTe and CuInSe{sub 2} cells. Notably, CdTe cells from Photon Energy have reduced window photocurrent losses to 1 mA/Cm{sup 2}; those from the University of South Florida have achieved a maximum power voltage of 693 mV; and CuInSe{sub 2} cells from International Solar Electric Technology have shown a hole density as high as 7 {times} 10{sup 16} cm{sup {minus}3}, implying a significant reduction in compensation. 9 refs.

  3. Thermoelectric study of crossroads material MnTe via sulfur doping

    SciTech Connect (OSTI)

    Xie, Wenjie Populoh, Sascha; Sagarna, Leyre; Trottmann, Matthias; Ga??zka, Krzysztof; Xiao, Xingxing; Liu, Yufei; He, Jian; Weidenkaff, Anke

    2014-03-14

    Here, we report thermoelectric study of crossroads material MnTe via iso-electronic doping S on the Te-site. MnTe{sub 1-x}S{sub x} samples with nominal S content of x?=?0.00, 0.05, and 0.10 were prepared using a melt-quench method followed by pulverization and spark plasma sintering. The X-ray powder diffraction, scanning electron microscopy, and ZAF-corrected compositional analysis confirmed that S uniformly substitutes Te up to slightly over 2%. A higher content of S in the starting materials led to the formation of secondary phases. The thermoelectric properties of MnTe{sub 1-x}S{sub x} samples were characterized by means of Seebeck coefficient, electrical conductivity, and thermal conductivity measurements from 300?K to 773?K. Furthermore, Hall coefficient measurements and a single parabolic band model were used to help gain insights on the effects of S-doping on the scattering mechanism and the carrier effective mass. As expected, S doping not only introduced hole charge carriers but also created short-range defects that effectively scatter heat-carrying phonons at elevated temperatures. On the other hand, we found that S doping degraded the effective mass. As a result, the ZT of MnTe{sub 0.9}S{sub 0.1} was substantially enhanced over the pristine sample near 400?K, while the improvement of ZT became marginal at elevated temperatures. A ZT???0.65 at 773?K was obtained in all three samples.

  4. Charge transport properties of p-CdTe/n-CdTe/n{sup +}-Si diode-type nuclear radiation detectors based on metalorganic vapor-phase epitaxy-grown epilayers

    SciTech Connect (OSTI)

    Niraula, M.; Yasuda, K.; Wajima, Y.; Yamashita, H.; Tsukamoto, Y.; Suzuki, Y.; Matsumoto, M.; Takai, N.; Tsukamoto, Y.; Agata, Y.

    2013-10-28

    Charge transport properties of p-CdTe/n-CdTe/n{sup +}-Si diode-type nuclear radiation detectors, fabricated by growing p-and n-type CdTe epilayers on (211) n{sup +}-Si substrates using metalorganic vapor-phase epitaxy (MOVPE), were studied by analyzing current-voltage characteristics measured at various temperatures. The diode fabricated shows good rectification properties, however, both forward and reverse biased currents deviate from their ideal behavior. The forward current exhibits typical feature of multi-step tunneling at lower biases; however, becomes space charge limited type when the bias is increased. On the other hand, the reverse current exhibits thermally activated tunneling-type current. It was found that trapping centers at the p-CdTe/n-CdTe junction, which were formed due to the growth induced defects, determine the currents of this diode, and hence limit the performance of the nuclear radiation detectors developed.

  5. High efficiency thin film CdTe and a-Si based solar cells

    SciTech Connect (OSTI)

    Compaan, A. D.; Deng, X.; Bohn, R. G.

    2000-01-04

    This report describes work done by the University of Toledo during the first year of this subcontract. During this time, the CdTe group constructed a second dual magnetron sputter deposition facility; optimized reactive sputtering for ZnTe:N films to achieve 10 ohm-cm resistivity and {approximately}9% efficiency cells with a copper-free ZnTe:N/Ni contact; identified Cu-related photoluminescence features and studied their correlation with cell performance including their dependence on temperature and E-fields; studied band-tail absorption in CdS{sub x}Te{sub 1{minus}x} films at 10 K and 300 K; collaborated with the National CdTe PV Team on (1) studies of high-resistivity tin oxide (HRT) layers from ITN Energy Systems, (2) fabrication of cells on the HRT layers with 0, 300, and 800-nm CdS, and (3) preparation of ZnTe:N-based contacts on First Solar materials for stress testing; and collaborated with Brooklyn College for ellipsometry studies of CdS{sub x}Te{sub 1{minus}x} alloy films, and with the University of Buffalo/Brookhaven NSLS for synchrotron X-ray fluorescence studies of interdiffusion in CdS/CdTe bilayers. The a-Si group established a baseline for fabricating a-Si-based solar cells with single, tandem, and triple-junction structures; fabricated a-Si/a-SiGe/a-SiGe triple-junction solar cells with an initial efficiency of 9.7% during the second quarter, and 10.6% during the fourth quarter (after 1166 hours of light-soaking under 1-sun light intensity at 50 C, the 10.6% solar cells stabilized at about 9%); fabricated wide-bandgap a-Si top cells, the highest Voc achieved for the single-junction top cell was 1.02 V, and top cells with high FF (up to 74%) were fabricated routinely; fabricated high-quality narrow-bandgap a-SiGe solar cells with 8.3% efficiency; found that bandgap-graded buffer layers improve the performance (Voc and FF) of the narrow-bandgap a-SiGe bottom cells; and found that a small amount of oxygen partial pressure ({approximately}2 {times} 10{sup {minus}5} torr) was beneficial for growing high-quality films from ITO targets.

  6. Origin of Novel Diffusions of Cu and Ag in Semiconductors: The Case of CdTe

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | DOE PAGES Origin of Novel Diffusions of Cu and Ag in Semiconductors: The Case of CdTe « Prev Next » Title: Origin of Novel Diffusions of Cu and Ag in Semiconductors: The Case of CdTe Authors: Ma, Jie ; Wei, Su-Huai Publication Date: 2013-06-04 OSTI Identifier: 1102795 Type: Publisher's Accepted Manuscript Journal Name: Physical Review Letters Additional Journal Information: Journal Volume: 110; Journal Issue: 23; Journal ID: ISSN 0031-9007 Publisher: American Physical

  7. Higgs production and decay from TeV scale black holes at the LHC (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Higgs production and decay from TeV scale black holes at the LHC Citation Details In-Document Search Title: Higgs production and decay from TeV scale black holes at the LHC We perform a detailed study of the Higgs production and decay, when Higgs is emitted from the black holes produced in proton-proton collisions at the Large Hadron Collider. We show that black hole production can significantly enhance the signal for the Higgs search at the LHC. We evaluate

  8. Indexing and TEM Sample Preparation of Isolated CdTe/CdS Nano-Islands.

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: Indexing and TEM Sample Preparation of Isolated CdTe/CdS Nano-Islands. Citation Details In-Document Search Title: Indexing and TEM Sample Preparation of Isolated CdTe/CdS Nano-Islands. Abstract not provided. Authors: Aguirre, Brandon Adrian ; Cruz-Campa, Jose Luis ; Jungjohann, Katherine Leigh ; Pete, Douglas V. ; Zubia, David Publication Date: 2014-03-01 OSTI Identifier: 1140918 Report Number(s): SAND2014-2312C 505756 DOE Contract Number:

  9. Optical Observations of Gamma-Ray Bursts: Connections to GeV/TeV Jets

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: Optical Observations of Gamma-Ray Bursts: Connections to GeV/TeV Jets Citation Details In-Document Search Title: Optical Observations of Gamma-Ray Bursts: Connections to GeV/TeV Jets Authors: Vestrand, W. Thomas [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2013-08-21 OSTI Identifier: 1091318 Report Number(s): LA-UR-13-26624 DOE Contract Number: AC52-06NA25396 Resource Type: Conference Resource Relation: Conference:

  10. Searching for neutrinoless double-beta decay of {sup 130}Te with CUORE

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Searching for neutrinoless double-beta decay of {sup 130}Te with CUORE Citation Details In-Document Search Title: Searching for neutrinoless double-beta decay of {sup 130}Te with CUORE Neutrinoless double-beta (0#23;{nu}{beta}{beta}#12;#12;) decay is a hypothesized lepton-number-violating process that offers the only known means of asserting the possible Majorana nature of neutrino mass. The Cryogenic Underground Observatory for Rare Events (CUORE) is an

  11. Dijet production in s=7 TeV pp collisions with large rapidity gaps at the

    Office of Scientific and Technical Information (OSTI)

    ATLAS experiment (Journal Article) | SciTech Connect Dijet production in s=7 TeV pp collisions with large rapidity gaps at the ATLAS experiment Citation Details In-Document Search Title: Dijet production in s = 7 TeV pp collisions with large rapidity gaps at the ATLAS experiment Publication Date: 2016-03-01 OSTI Identifier: 1235497 Type: Published Article Journal Name: Physics Letters. Section B Additional Journal Information: Journal Volume: 754; Journal Issue: C; Journal ID: ISSN 0370-2693

  12. Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Terahertz-Induced Response of GeSbTe Phase-Change Materials Citation Details In-Document Search Title: Ultrafast Terahertz-Induced Response of GeSbTe Phase-Change Materials × 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 Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science and

  13. Preliminary design for a 20 TeV Collider in a deep tunnel at Fermilab

    SciTech Connect (OSTI)

    Not Available

    1985-01-12

    The Reference Design Study for a 20 TeV Collider demonstrated the technical and cost feasibility of a 20 TeV superconducting collider facility. Based on magnets of 3T, 5T, and 6.5T the Main Ring of the Collider would have a circumference of 164 km, 113 km, or 90 km. There would be six collision regions, of which four would be developed intially. The 5T and 6.5T rings would have twelve major refrigeration stations, while the 3T design would have 24 major refrigeration stations.

  14. Aqueous Synthesis of Zinc Blende CdTe/CdS Magic-Core/Thick-Shell

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

    Tetrahedral Shaped Nanocrystals with Emission Tunable to Near-Infrared Aqueous Synthesis of Zinc Blende CdTe/CdS Magic-Core/Thick-Shell Tetrahedral Shaped Nanocrystals with Emission Tunable to Near-Infrared Authors: Deng, Z., Schulz, O., Lin, S., Ding, B., Liu, X., Wei, X., Ros, R., Liu, Y., Yan, H., and Francis, M. Title: Aqueous Synthesis of Zinc Blende CdTe/CdS Magic-Core/Thick-Shell Tetrahedral Shaped Nanocrystals with Emission Tunable to Near-Infrared Source: Journal of the American

  15. Renaissance of the ~1 TeV Fixed-Target Program

    SciTech Connect (OSTI)

    Adams, T.; Appel, Jeffrey A.; Arms, Kregg Elliott; Balantekin, A.B.; Conrad, Janet Marie; Cooper, Peter S.; Djurcic, Zelimir; Dunwoodie, William M.; Engelfried, Jurgen; Fisher, Peter H.; Gottschalk, E.; /Fermilab /Northwestern U.

    2009-05-01

    This document describes the physics potential of a new fixed-target program based on a {approx} TeV proton source. Two proton sources are potentially available in the future: the existing Tevatron at Fermilab, which can provide 800 GeV protons for fixed-target physics, and a possible upgrade to the SPS at CERN, called SPS+, which would produce 1 TeV protons on target. In this paper we use an example Tevatron fixed-target program to illustrate the high discovery potential possible in the charm and neutrino sectors. We highlight examples which are either unique to the program or difficult to accomplish at other venues.

  16. Renaissance of the ~ 1-TeV Fixed-Target Program

    SciTech Connect (OSTI)

    Adams, T.; Appel, J.A.; Arms, K.E.; Balantekin, A.B.; Conrad, J.M.; Cooper, P.S.; Djurcic, Z.; Dunwoodie, W.; Engelfried, J.; Fisher, P.H.; Gottschalk, Erik Edward; de Gouvea, A.; Heller, K.; Ignarra, C.M.; Karagiorgi, G.; Kwan, S.; Loinaz, W.A.; Meadows, B.; Moore, R.; Morfin, J.G.; Naples, D.; /Pittsburgh U. /St. Mary's Coll., Minnesota /New Mexico State U. /Michigan U. /Wayne State U. /South Carolina U. /Florida U. /Carnegie Mellon U. /Cincinnati U. /Columbia U. /Columbia U. /Northwestern U. /Yale U. /Fermilab /Argonne /Northwestern U. /APC, Paris

    2011-12-02

    This document describes the physics potential of a new fixed-target program based on a {approx}1 TeV proton source. Two proton sources are potentially available in the future: the existing Tevatron at Fermilab, which can provide 800 GeV protons for fixed-target physics, and a possible upgrade to the SPS at CERN, called SPS+, which would produce 1 TeV protons on target. In this paper we use an example Tevatron fixed-target program to illustrate the high discovery potential possible in the charm and neutrino sectors. We highlight examples which are either unique to the program or difficult to accomplish at other venues.

  17. .sup.123m Te-Labeled biochemicals and method of preparation

    DOE Patents [OSTI]

    Knapp, Jr., Furn F. (Oak Ridge, TN)

    1980-01-01

    A novel class of .sup.123m Te-labeled steroids and amino acids is provided by the method of reacting a .sup.123m Te symmetric diorgano ditelluride with a hydride reducing agent and a source of alkali metal ions to form an alkali metal organo telluride. The alkali metal organo telluride is reacted with a primary halogenated steroidal side chain, amino acid, or amino acid precursor such as hydantoin. The novel compounds are useful as biological tracers and as organal imaging agents.

  18. Passivation of an isoelectronic impurity by atomic hydrogen: The case of ZnTe:O

    SciTech Connect (OSTI)

    Felici, Marco; Polimeni, Antonio; Capizzi, Mario; Nabetani, Y.; Okuno, T.; Aoki, K.; Kato, T.; Matsumoto, T.; Hirai, T.

    2006-03-06

    We investigated the optical properties of ZnTe:O/GaAs before and after atomic hydrogen irradiation. Oxygen incorporation gives rise to energy levels associated with single O atoms, O-O pairs, and O clusters, and to a blueshift of the energy gap of the material with respect to that of pure ZnTe/GaAs. All of these effects disappear progressively after irradiation with H, which also leads to an increase in the tensile strain of the epilayer. These observations provide experimental evidence of H-induced passivation of an isoelectronic impurity in II-VI alloys.

  19. Shape-controlled narrow-gap SnTe nanostructures: From nanocubes to nanorods

    Office of Scientific and Technical Information (OSTI)

    and nanowires (Journal Article) | SciTech Connect Shape-controlled narrow-gap SnTe nanostructures: From nanocubes to nanorods and nanowires Citation Details In-Document Search This content will become publicly available on November 6, 2016 Title: Shape-controlled narrow-gap SnTe nanostructures: From nanocubes to nanorods and nanowires In this study, the rational design and synthesis of narrow-gap colloidal semiconductor nanocrystals (NCs) is an important step toward the next generation of

  20. Spectral weight transfer in strongly correlated Fe{1.03} T{e} (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Spectral weight transfer in strongly correlated Fe{1.03} T{e} Citation Details In-Document Search Title: Spectral weight transfer in strongly correlated Fe{1.03} T{e} Authors: Dai, Y.M. ; Akrap, A. ; Schneeloch, J. ; Zhong, R.D. ; Liu, T.S. ; Gu, G. ; Li, Q. ; Homes, C.C. Publication Date: 2014-09-30 OSTI Identifier: 1210288 DOE Contract Number: AC02-98CH10886 Resource Type: Journal Article Resource Relation: Journal Name: Physical Review B; Journal Volume: 90;

  1. Local-moment magnetism in superconducting FeTe0.35Se0.65 as seen...

    Office of Scientific and Technical Information (OSTI)

    Local-moment magnetism in superconducting FeTe0.35Se0.65 as seen via inelastic neutron scattering Prev Next Title: Local-moment magnetism in superconducting FeTe0.35Se0.65 as ...

  2. Cadmium sulfate and CdTe-quantum dots alter DNA repair in zebrafish (Danio rerio) liver cells

    SciTech Connect (OSTI)

    Tang, Song; Cai, Qingsong; Chibli, Hicham; Allagadda, Vinay; Nadeau, Jay L.; Mayer, Gregory D.

    2013-10-15

    Increasing use of quantum dots (QDs) makes it necessary to evaluate their toxicological impacts on aquatic organisms, since their contamination of surface water is inevitable. This study compares the genotoxic effects of ionic Cd versus CdTe nanocrystals in zebrafish hepatocytes. After 24 h of CdSO{sub 4} or CdTe QD exposure, zebrafish liver (ZFL) cells showed a decreased number of viable cells, an accumulation of Cd, an increased formation of reactive oxygen species (ROS), and an induction of DNA strand breaks. Measured levels of stress defense and DNA repair genes were elevated in both cases. However, removal of bulky DNA adducts by nucleotide excision repair (NER) was inhibited with CdSO{sub 4} but not with CdTe QDs. The adverse effects caused by acute exposure of CdTe QDs might be mediated through differing mechanisms than those resulting from ionic cadmium toxicity, and studying the effects of metallic components may be not enough to explain QD toxicities in aquatic organisms. - Highlights: Both CdSO{sub 4} and CdTe QDs lead to cell death and Cd accumulation. Both CdSO{sub 4} and CdTe QDs induce cellular ROS generation and DNA strand breaks. Both CdSO{sub 4} and CdTe QDs induce the expressions of stress defense and DNA repair genes. NER repair capacity was inhibited with CdSO{sub 4} but not with CdTe QDs.

  3. Sonochemical and hydrothermal synthesis of PbTe nanostructures with the aid of a novel capping agent

    SciTech Connect (OSTI)

    Fard-Fini, Shahla Ahmadian; Salavati-Niasari, Masoud; Mohandes, Fatemeh

    2013-10-15

    Graphical abstract: - Highlights: PbTe nanostructures were prepared with the aid of Schiff-base compound. Sonochemical and hydrothermal methods were employed to fabricate PbTe nanostrucrues. The effect of preparation parameters on the morphology of PbTe was investigated. - Abstract: In this work, a new Schiff-base compound derived from 1,8-diamino-3,6-dioxaoctane and 2-hydroxy-1-naphthaldehyde marked as (2-HyNa)-(DaDo) was synthesized, characterized, and then used as capping agent for the preparation of PbTe nanostructures. To fabricate PbTe nanostructures, two different synthesis methods; hydrothermal and sonochemical routes, were applied. To further investigate, the effect of preparation parameters like reaction time and temperature in hydrothermal synthesis and sonication time in the presence of ultrasound irradiation on the morphology and purity of the final products was tested. The products were analyzed with the aid of SEM, TEM, XRD, FT-IR, and EDS. Based on the obtained results, it was found that pure cubic phased PbTe nanostructures have been obtained by hydrothermal and sonochemical approaches. Besides, SEM images showed that cubic-like and rod-like PbTe nanostructures have been formed by hydrothermal and sonochemical methods, respectively. Sonochemical synthesis of PbTe nanostructures was favorable, because the synthesis time of sonochemical method was shorter than that of hydrothermal method.

  4. Study of W boson production in pPb collisions at sNN=5.02 TeV...

    Office of Scientific and Technical Information (OSTI)

    Study of W boson production in pPb collisions at sNN5.02 TeV Citation Details In-Document Search Title: Study of W boson production in pPb collisions at sNN5.02 TeV Publication...

  5. Evaluation of the ²³⁹Pu prompt fission neutron spectrum induced by neutrons of 500 keV and associated covariances

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

    Neudecker, D.; Talou, P.; Kawano, T.; Smith, D. L.; Capote, R.; Rising, M. E.; Kahler, A. C.

    2015-08-01

    We present evaluations of the prompt fission neutron spectrum (PFNS) of ²³⁹Pu induced by 500 keV neutrons, and associated covariances. In a previous evaluation by Talou et al. 2010, surprisingly low evaluated uncertainties were obtained, partly due to simplifying assumptions in the quantification of uncertainties from experiment and model. Therefore, special emphasis is placed here on a thorough uncertainty quantification of experimental data and of the Los Alamos model predicted values entering the evaluation. In addition, the Los Alamos model was extended and an evaluation technique was employed that takes into account the qualitative differences between normalized model predicted valuesmore » and experimental shape data. These improvements lead to changes in the evaluated PFNS and overall larger evaluated uncertainties than in the previous work. However, these evaluated uncertainties are still smaller than those obtained in a statistical analysis using experimental information only, due to strong model correlations. Hence, suggestions to estimate model defect uncertainties are presented, which lead to more reasonable evaluated uncertainties. The calculated keff of selected criticality benchmarks obtained with these new evaluations agree with each other within their uncertainties despite the different approaches to estimate model defect uncertainties. The keff one standard deviations overlap with some of those obtained using ENDF/B-VII.1, albeit their mean values are further away from unity. Spectral indexes for the Jezebel critical assembly calculated with the newly evaluated PFNS agree with the experimental data for selected (n,γ) and (n,f) reactions, and show improvements for high-energy threshold (n,2n) reactions compared to ENDF/B-VII.1.« less

  6. Theoretical analyses of (n,xn) reactions on sup 235 U, sup 238 U, sup 237 Np, and sup 239 Pu for ENDF/B-VI

    SciTech Connect (OSTI)

    Young, P.G.; Arthur, E.D.

    1991-01-01

    Theoretical analyses were performed of neutron-induced reactions on {sup 235}U, {sup 238}U, {sup 237}Np, and {sup 239}Pu between 0.01 and 20 MeV in order to calculate neutron emission cross sections and spectra for ENDF/B-VI evaluations. Coupled-channel optical model potentials were obtained for each target nucleus by fitting total, elastic, and inelastic scattering cross section data, as well as low-energy average resonance data. The resulting deformed optical model potentials were used to calculate direct (n,n{prime}) cross sections and transmission coefficients for use in Hauser-Feshbach statistical theory analyses. A fission model with multiple barrier representation, width fluctuation corrections, and preequilibrium corrections were included in the analyses. Direct cross sections for higher-lying vibrational states were calculated using DWBA theory, normalized using B(E{ell}) values determined from (d,d{prime}) and Coulomb excitation data, where available, and from systematics otherwise. Initial fission barrier parameters and transition state density enhancements appropriate to the compound systems involved were obtained from previous analyses, especially fits to charged-particle fission probability data. The parameters for the fission model were adjusted for each target system to obtain optimum agreement with direct (n,f) cross section measurements, taking account of the various multichance fission channels, that is, the different compound systems involved. The results from these analyses were used to calculate most of the neutron (n,n), (n,n{prime}), and (n,xn) cross section data in the ENDF/B/VI evaluations for the above nuclei, and all of the energy-angle correlated spectra. The deformed optical model and fission model parameterizations are described. Comparisons are given between the results of these analyses and the previous ENDF/B-V evaluations as well as with the available experimental data. 14 refs., 3 figs., 1 tab.

  7. Co-operativity among defect sites in AnO2+ and An4O9 (An = U, Np or Pu)

    SciTech Connect (OSTI)

    Andersson, Anders David; Lezama Pacheco, Juan; Uberuaga, Blas P; Conradson, Steven D

    2008-01-01

    Actinide dioxides derived from the AnO{sub 2} fluorite lattice are of high technological relevance due to their application in nuclear reactor fuels. Oxidation of AnO{sub 2} compounds emerges as a central theme in fuel fabrication, reactor operation, long-term storage forms for both spent fuels and surplus weapons materials, and environmental actinide migration. In this paper, we use density functional theory calculations to study the oxidation of uranium, neptunium and plutonium dioxides, AnO{sub 2} (An = U, Np or Pu), in O{sub 2} and O{sub 2}/H{sub 2}O environments. We pay particular attention to the formation of oxygen clusters (co-operativity) in AnO{sub 2+x} and how this phenomenon govern oxidation thermodynamics and the development of ordered An{sub 4}O{sub 9} compounds. The so-called split di-interstitial, which is composed of two nearest neighbor octahedral oxygen interstitials that are distorted in such a way that they dislocate one regular fluorite lattice oxygen ion to form a cluster of triangular geometry, is predicted to be the fundamental building block of the most stable cluster configurations. We also identify how the formation of oxygen defect clusters and the degree of oxidation in AnO{sub 2+x} are both governed by the characer of the An-5f to excess O-2p charger transfer, i.e. the charge transfer to the O-2p orbitals of the interstitial-like (+x) ions, and the ability of the excess O-2p orbitals to hybridize with regular fluorite lattice ions.

  8. Reliability, O&M, Standards Development

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

    Lab Photovoltaic Systems Evaluation Laboratory PV Regional ... Facility Geomechanics and Drilling Labs National ... (including future offshore units) to influence the ...

  9. Om Power Corporation Ltd | Open Energy Information

    Open Energy Info (EERE)

    Ltd. Place: Palampur, Himachal Pradesh, India Sector: Hydro Product: Palampur-based small hydro project developer. Coordinates: 32.110378, 76.535988 Show Map Loading...

  10. Nanowire CdS-CdTe solar cells with molybdenum oxide as contact

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

    Dang, Hongmei; Singh, Vijay P.

    2015-10-06

    Using a 10 nm thick molybdenum oxide (MoO3-x) layer as a transparent and low barrier contact to p-CdTe, we demonstrate nanowire CdS-CdTe solar cells with a power conversion efficiency of 11% under front side illumination. Annealing the as-deposited MoO3 film in N2 resulted in a reduction of the cell’s series resistance, from 9.97 Ω/cm2 to 7.69 Ω/cm2, and increase in efficiency from 9.9% to 11%. Under illumination from the back, the MoO3-x/Au side, the nanowire solar cells yielded Jsc of 21 mA/cm2 and efficiency of 8.67%. Our results demonstrate use of a thin layer transition metal oxide as a potentialmore » way for a transparent back contact to nanowire CdS-CdTe solar cells. As a result, this work has implications toward enabling a novel superstrate structure nanowire CdS-CdTe solar cell on Al foil substrate by a low cost roll-to roll fabrication process.« less

  11. Nuclear structure relevant to neutrinoless double beta decay candidate {sup 130}Te and other recent results

    SciTech Connect (OSTI)

    Kay, B. P. [Physics Division, Argonne National Laboratory, Illinois 60439 (United States)

    2013-12-30

    We have undertaken a series of single-nucleon and pair transfer reaction measurements to help constrain calculations of the nuclear matrix elements for neutrinoless double beta decay. In this talk, a short overview of measurements relevant to the {sup 130}Te?{sup 130}Xe system is given. Brief mention is made of other recent and forthcoming results.

  12. Investigation of deep level defects in CdTe thin films

    SciTech Connect (OSTI)

    Shankar, H.; Castaldini, A.; Dauksta, E.; Medvid, A.; Cavallini, A.

    2014-02-21

    In the past few years, a large body of work has been dedicated to CdTe thin film semiconductors, as the electronic and optical properties of CdTe nanostructures make them desirable for photovoltaic applications. The performance of semiconductor devices is greatly influenced by the deep levels. Knowledge of parameters of deep levels present in as-grown materials and the identification of their origin is the key factor in the development of photovoltaic device performance. Photo Induced Current Transient Spectroscopy technique (PICTS) has proven to be a very powerful method for the study of deep levels enabling us to identify the type of traps, their activation energy and apparent capture cross section. In the present work, we report the effect of growth parameters and LASER irradiation intensity on the photo-electric and transport properties of CdTe thin films prepared by Close-Space Sublimation method using SiC electrical heating element. CdTe thin films were grown at three different source temperatures (630, 650 and 700 C). The grown films were irradiated with Nd:YAG LASER and characterized by Photo-Induced Current Transient Spectroscopy, Photocurrent measurementand Current Voltage measurements. The defect levels are found to be significantly influenced by the growth temperature.

  13. Shape-controlled narrow-gap SnTe nanostructures: From nanocubes to nanorods and nanowires

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

    Guo, Shaojun; Andrew F. Fidler; He, Kai; Su, Dong; Chen, Gen; Lin, Qianglu; Pietryga, Jeffrey M.; Klimov, Victor I.

    2015-11-06

    In this study, the rational design and synthesis of narrow-gap colloidal semiconductor nanocrystals (NCs) is an important step toward the next generation of solution-processable photovoltaics, photodetectors, and thermoelectric devices. SnTe NCs are particularly attractive as a Pb-free alternative to NCs of narrow-gap lead chalcogenides. Previous synthetic efforts on SnTe NCs have focused on spherical nanoparticles. Here we report new strategies for synthesis of SnTe NCs with shapes tunable from highly monodisperse nanocubes, to nanorods (NRs) with variable aspect ratios, and finally to long, straight nanowires (NWs). Reaction at high temperature quickly forms thermodynamically favored nanocubes, but low temperatures lead tomore » elongated particles. Transmission electron microscopy studies of reaction products at various stages of the synthesis reveal that the growth and shape-focusing of monodisperse SnTe nanocubes likely involves interparticle ripening, while directional growth of NRs and NWs may be initiated by particle dimerization via oriented attachment.« less

  14. Low-temperature photoluminescence analysis of CdTeSe crystals for radiation-detector applications

    SciTech Connect (OSTI)

    YANG G.; Roy, U. N.; Bolotnikov, A. E.; Cui, Y.; Camarda, G.S.; Hossain, A.; and James, R. B.

    2015-10-05

    Goal: Understanding the changes of material defects in CdTeSe following annealing. Experimental results and discussions: Infrared (IR) transmission microscopy; current-voltage measurements (Highlight: Improvement of resistivity of un-doped crystals after annealing); low-temperature photoluminescence (PL) spectrum of as-grown and annealed samples.

  15. Project Reports for Te-Moak Tribe of Western Shoshone: Battle Mountain Colony- 2012 Project

    Broader source: Energy.gov [DOE]

    The Feasibility Study for the Battle Mountain Renewable Energy Park project ("Feasibility Study") will assess the feasibility, benefits, and impacts of a 5-megawatt (MW) solar photovoltaic (PV) generating system (the "Solar Project" or "Energy Park") on the Te-Moak Tribe of Western Shoshone Indians of Nevada Battle Mountain Colony in Battle Mountain, Nevada.

  16. Te-Moak Tribe of Western Shoshone: Battle Mountain Colony- 2012 Project

    Broader source: Energy.gov [DOE]

    The Feasibility Study for the Battle Mountain Renewable Energy Park project ("Feasibility Study") will assess the feasibility, benefits, and impacts of a 5-megawatt (MW) solar photovoltaic (PV) generating system (the "Solar Project" or "Energy Park") on the Te-Moak Tribe of Western Shoshone Indians of Nevada Battle Mountain Colony in Battle Mountain, Nevada.

  17. 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.

  18. Nanowire CdS-CdTe solar cells with molybdenum oxide as contact

    SciTech Connect (OSTI)

    Dang, Hongmei; Singh, Vijay P.

    2015-10-06

    Using a 10 nm thick molybdenum oxide (MoO3-x) layer as a transparent and low barrier contact to p-CdTe, we demonstrate nanowire CdS-CdTe solar cells with a power conversion efficiency of 11% under front side illumination. Annealing the as-deposited MoO3 film in N2 resulted in a reduction of the cell’s series resistance, from 9.97 Ω/cm2 to 7.69 Ω/cm2, and increase in efficiency from 9.9% to 11%. Under illumination from the back, the MoO3-x/Au side, the nanowire solar cells yielded Jsc of 21 mA/cm2 and efficiency of 8.67%. Our results demonstrate use of a thin layer transition metal oxide as a potential way for a transparent back contact to nanowire CdS-CdTe solar cells. As a result, this work has implications toward enabling a novel superstrate structure nanowire CdS-CdTe solar cell on Al foil substrate by a low cost roll-to roll fabrication process.

  19. Higgs Coupling Measurements at a 1 TeV Linear Collider

    SciTech Connect (OSTI)

    Barklow, T

    2003-12-18

    Methods for extracting Higgs boson signals at a 1 TeV center-of-mass energy e{sup +}e{sup -} linear collider are described. In addition, estimates are given for the accuracy with which branching fractions can be measured for Higgs boson decays to b{bar b} WW, gg, and {gamma}{gamma}.

  20. Relic neutralino surface at a 100 TeV collider

    SciTech Connect (OSTI)

    Bramante, Joseph; Fox, Patrick J.; Martin, Adam; Ostdiek, Bryan; Plehn, Tilman; Schell, Torben; Takeuchi, Michihisa

    2015-03-11

    We map the parameter space for minimal supersymmetric Standard Model neutralino dark matter which freezes out to the observed relic abundance, in the limit that all superpartners except the neutralinos and charginos are decoupled. In this space of relic neutralinos, we show the dominant dark matter annihilation modes, the mass splittings among the electroweakinos, direct detection rates, and collider cross sections. The mass difference between the dark matter and the next-to-lightest neutral and charged states is typically much less than electroweak gauge boson masses. With these small mass differences, the relic neutralino surface is accessible to a future 100 TeV hadron collider, which can discover interneutralino mass splittings down to 1 GeV and thermal relic dark matter neutralino masses up to 1.5 TeV with a few inverse attobarns of luminosity. This coverage is a direct consequence of the increased collider energy: in the Standard Model events with missing transverse momentum in the TeV range have mostly hard electroweak radiation, distinct from the soft radiation shed in compressed electroweakino decays. As a result, we exploit this kinematic feature in final states including photons and leptons, tailored to the 100 TeV collider environment.

  1. Relic neutralino surface at a 100 TeV collider

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

    Bramante, Joseph; Fox, Patrick J.; Martin, Adam; Ostdiek, Bryan; Plehn, Tilman; Schell, Torben; Takeuchi, Michihisa

    2015-03-11

    We map the parameter space for minimal supersymmetric Standard Model neutralino dark matter which freezes out to the observed relic abundance, in the limit that all superpartners except the neutralinos and charginos are decoupled. In this space of relic neutralinos, we show the dominant dark matter annihilation modes, the mass splittings among the electroweakinos, direct detection rates, and collider cross sections. The mass difference between the dark matter and the next-to-lightest neutral and charged states is typically much less than electroweak gauge boson masses. With these small mass differences, the relic neutralino surface is accessible to a future 100 TeVmore » hadron collider, which can discover interneutralino mass splittings down to 1 GeV and thermal relic dark matter neutralino masses up to 1.5 TeV with a few inverse attobarns of luminosity. This coverage is a direct consequence of the increased collider energy: in the Standard Model events with missing transverse momentum in the TeV range have mostly hard electroweak radiation, distinct from the soft radiation shed in compressed electroweakino decays. As a result, we exploit this kinematic feature in final states including photons and leptons, tailored to the 100 TeV collider environment.« less

  2. Impact of annealing on the chemical structure and morphology of the thin-film CdTe/ZnO interface

    SciTech Connect (OSTI)

    Horsley, K. Hanks, D. A.; Weir, M. G.; Beal, R. J.; Wilks, R. G.; Blum, M.; Hming, M.; Hofmann, T.; Weinhardt, L.; and others

    2014-07-14

    To enable an understanding and optimization of the optoelectronic behavior of CdTe-ZnO nanocomposites, the morphological and chemical properties of annealed CdTe/ZnO interface structures were studied. For that purpose, CdTe layers of varying thickness (424?nm) were sputter-deposited on 100?nm-thick ZnO films on surface-oxidized Si(100) substrates. The morphological and chemical effects of annealing at 525?C were investigated using X-ray Photoelectron Spectroscopy (XPS), X-ray-excited Auger electron spectroscopy, energy dispersive X-ray spectroscopy, scanning electron microscopy, and atomic force microscopy. We find a decrease of the Cd and Te surface concentration after annealing, parallel to an increase in Zn and O signals. While the as-deposited film surfaces show small grains (100?nm diameter) of CdTe on the ZnO surface, annealing induces a significant growth of these grains and separation into islands (with diameters as large as 1??m). The compositional change at the surface is more pronounced for Cd than for Te, as evidenced using component peak fitting of the Cd and Te 3d XPS peaks. The modified Auger parameters of Cd and Te are also calculated to further elucidate the local chemical environment before and after annealing. Together, these results suggest the formation of tellurium and cadmium oxide species at the CdTe/ZnO interface upon annealing, which can create a barrier for charge carrier transport, and might allow for a deliberate modification of interface properties with suitably chosen thermal treatment parameters.

  3. Simulation, Modeling, and Crystal Growth of Cd0.9Zn0.1Te for Nuclear

    Office of Scientific and Technical Information (OSTI)

    Spectrometers (Journal Article) | SciTech Connect Simulation, Modeling, and Crystal Growth of Cd0.9Zn0.1Te for Nuclear Spectrometers Citation Details In-Document Search Title: Simulation, Modeling, and Crystal Growth of Cd0.9Zn0.1Te for Nuclear Spectrometers High-quality, large (10 cm long and 2.5 cm diameter), nuclear spectrometer grade Cd{sub 0.9}Zn{sub 0.1}Te (CZT) single crystals have been grown by a controlled vertical Bridgman technique using in-house zone refined precursor materials

  4. Search for contact interactions in dimuon events from pp collisions at ?s=7 TeV with the ATLAS detector

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

    Aad, G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; Abramowicz, H.; Abreu, H.; et al

    2011-07-01

    A search for contact interactions has been performed using dimuon events recorded with the ATLAS detector in proton-proton collisions at ?s=7 TeV. The data sample corresponds to an integrated luminosity of 42 pb?. No significant deviation from the standard model is observed in the dimuon mass spectrum, allowing the following 95% C.L. limits to be set on the energy scale of contact interactions: ?>4.9 TeV (4.5 TeV) for constructive (destructive) interference in the left-left isoscalar compositeness model. These limits are the most stringent to date for ??qq contact interactions.

  5. Desired PU Loading During Vitrification

    Office of Environmental Management (EM)

  6. Role of chalcogen vapor annealing in inducing bulk superconductivity in Fe1+yTe1-xSex [How does annealing in chalcogen vapor induce superconductivity in Fe1+yTe-xSex?

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

    Lin, Wenzhi; Ganesh, P.; Gianfrancesco, Anthony; Wang, Jun; Berlijn, Tom; Maier, Thomas A.; Kalinin, Sergei V.; Sales, Brian C.; Pan, Minghu

    2015-02-01

    Recent investigations have shown that Fe1+yTe1-xSex can be made superconducting by annealing it in Se and O vapors. The current lore is that these chalcogen vapors induce superconductivity by removing the magnetic excess Fe atoms. To investigate this phenomenon we performed a combination of magnetic susceptibility, specific heat and transport measurements together with scanning tunneling microscopy and spectroscopy and density functional theory calculations on Fe1+yTe1-xSex treated with Te vapor. We conclude that the main role of the Te vapor is to quench the magnetic moments of the excess Fe atoms by forming FeTem (m ≥ 1) complexes. We show thatmore » the remaining FeTem complexes are still damaging to the superconductivity and therefore that their removal potentially could further improve superconductive properties in these compounds.« less

  7. Modeling Cu Migration in CdTe Solar Cells Under Device-Processing and Long-Term Stability Conditions: Preprint

    SciTech Connect (OSTI)

    Teeter, G.; Asher, S.

    2008-05-01

    An impurity migration model for systems with material interfaces is applied to Cu migration in CdTe solar cells. In the model, diffusion fluxes are calculated from the Cu chemical potential gradient. Inputs to the model include Cu diffusivities, solubilities, and segregation enthalpies in CdTe, CdS and contact materials. The model yields transient and equilibrium Cu distributions in CdTe devices during device processing and under field-deployed conditions. Preliminary results for Cu migration in CdTe photovoltaic devices using available diffusivity and solubility data from the literature show that Cu segregates in the CdS, a phenomenon that is commonly observed in devices after back-contact processing and/or stress conditions.

  8. Polarization of Bi{sub 2}Te{sub 3} thin film in a floating-gate capacitor structure

    SciTech Connect (OSTI)

    Yuan, Hui E-mail: qli6@gmu.edu; Li, Haitao; Zhu, Hao; Zhang, Kai; Baumgart, Helmut; Bonevich, John E.; Richter, Curt A.; Li, Qiliang E-mail: qli6@gmu.edu

    2014-12-08

    Metal-Oxide-Semiconductor (MOS) capacitors with Bi{sub 2}Te{sub 3} thin film sandwiched and embedded inside the oxide layer have been fabricated and studied. The capacitors exhibit ferroelectric-like hysteresis which is a result of the robust, reversible polarization of the Bi{sub 2}Te{sub 3} thin film while the gate voltage sweeps. The temperature-dependent capacitance measurement indicates that the activation energy is about 0.33?eV for separating the electron and hole pairs in the bulk of Bi{sub 2}Te{sub 3}, and driving them to either the top or bottom surface of the thin film. Because of the fast polarization speed, potentially excellent endurance, and the complementary metaloxidesemiconductor compatibility, the Bi{sub 2}Te{sub 3} embedded MOS structures are very interesting for memory application.

  9. The effects of deep level traps on the electrical properties of semi-insulating CdZnTe

    SciTech Connect (OSTI)

    Zha, Gangqiang; Yang, Jian; Xu, Lingyan; Feng, Tao; Wang, Ning; Jie, Wanqi

    2014-01-28

    Deep level traps have considerable effects on the electrical properties and radiation detection performance of high resistivity CdZnTe. A deep-trap model for high resistivity CdZnTe was proposed in this paper. The high resistivity mechanism and the electrical properties were analyzed based on this model. High resistivity CdZnTe with high trap ionization energy E{sub t} can withstand high bias voltages. The leakage current is dependent on both the deep traps and the shallow impurities. The performance of a CdZnTe radiation detector will deteriorate at low temperatures, and the way in which sub-bandgap light excitation could improve the low temperature performance can be explained using the deep trap model.

  10. CdSe/CdTe type-II superlattices grown on GaSb (001) substrates by molecular beam epitaxy

    SciTech Connect (OSTI)

    Li Jingjing; Liu Shi; Wang Shumin; Ding Ding; Johnson, Shane R.; Zhang Yonghang; Liu Xinyu; Furdyna, Jacek K.; Smith, David J.

    2012-03-19

    CdSe/CdTe superlattices are grown on GaSb substrates using molecular beam epitaxy. X-ray diffraction measurements and cross-sectional transmission electron microscopy images indicate high crystalline quality. Photoluminescence (PL) measurements show the effective bandgap varies with the superlattice layer thicknesses and confirm the CdSe/CdTe heterostructure has a type-II band edge alignment. The valence band offset between unstrained CdTe and CdSe is determined as 0.63 {+-} 0.06 eV by fitting the measured PL peak positions using the envelope function approximation and the Kronig-Penney model. These results suggest that CdSe/CdTe superlattices are promising candidates for multi-junction solar cells and other optoelectronic devices based on GaSb substrates.

  11. Rare-earth-rich tellurides: Gd{sub 4}NiTe{sub 2} and Er{sub 5}M{sub 2}Te{sub 2} (M=Co, Ni)

    SciTech Connect (OSTI)

    Magliocchi, Carmela; Meng, Fanqin; Hughbanks, Timothy . E-mail: trh@mail.chem.tamu.edu

    2004-11-01

    Three new rare earth metal-rich compounds, Gd{sub 4}NiTe{sub 2}, and Er{sub 5}M{sub 2}Te{sub 2} (M=Ni, Co), were synthesized in direct reactions using R, R{sub 3}M, and R{sub 2}Te{sub 3} (R=Gd, Er; M=Co, Ni) and single-crystal structures were determined. Gd{sub 4}NiTe{sub 2} is orthorhombic and crystallizes in space group Pnma with four formula units per cell. Lattice parameters at 110(2)K are a=15.548(9), b=4.113(2), c=11.7521(15)A. Er{sub 5}Ni{sub 2}Te{sub 2} and Er{sub 5}Co{sub 2}Te{sub 2} are isostructural and crystallize in the orthorhombic space group Cmcm with two formula units per cell. Lattice parameters at 110(2)K are a=3.934(1), b=14.811(4), c=14.709(4)A, and a=3.898(1), b=14.920(3), c=14.889(3)A, respectively. Metal-metal bonding correlations were analyzed using the empirical Pauling bond order concept.

  12. Thermoelectric properties of polycrystalline In4Se3 and In4Te3

    SciTech Connect (OSTI)

    Shi, Xun; Cho, Jung Y; Salvador, James R.; Yang, Jihui; Wang, Hsin

    2010-01-01

    High thermoelectric performance of a single crystal layered compound In{sub 4}Se{sub 3} was reported recently. We present here an electrical and thermal transport property study over a wide temperature range for polycrystalline samples of In{sub 4}Se{sub 3} and In{sub 4}Te{sub 3}. Our data demonstrate that these materials are lightly doped semiconductors, leading to large thermopower and resistivity. Very low thermal conductivity, below 1 W/m K, is observed. The power factors for In{sub 4}Se{sub 3} and In{sub 4}Te{sub 3} are much smaller when compared with state-of-the-art thermoelectric materials. This combined with the very low thermal conductivity results in the maximum ZT value of less than 0.6 at 700 K for In{sub 4}Se{sub 3}.

  13. Search for Dijet Resonances in 7 TeV pp Collisions at CMS

    SciTech Connect (OSTI)

    Khachatryan, V.; et al.

    2010-11-01

    A search for narrow resonances in the dijet mass spectrum is performed using data corresponding to an integrated luminosity of 2.9 inverse pb collected by the CMS experiment at the LHC. Upper limits at the 95% confidence level (CL) are presented on the product of the resonance cross section, branching fraction into dijets, and acceptance, separately for decays into quark-quark, quark-gluon, or gluon-gluon pairs. The data exclude new particles predicted in the following models at the 95% CL: string resonances, with mass less than 2.50 TeV, excited quarks, with mass less than 1.58 TeV, and axigluons, colorons, and E_6 diquarks, in specific mass intervals. This extends previously published limits on these models.

  14. Photoluminescence studies of type-II CdSe/CdTe superlattices

    SciTech Connect (OSTI)

    Li Jingjing; Johnson, Shane R.; Wang Shumin; Ding Ding; Ning Cunzheng; Zhang Yonghang; Yin Leijun; Skromme, B. J.; Liu Xinyu; Furdyna, Jacek K.

    2012-08-06

    CdSe/CdTe type-II superlattices grown on GaSb substrates by molecular beam epitaxy are studied using time-resolved and steady-state photoluminescence (PL) spectroscopy at 10 K. The relatively long carrier lifetime of 188 ns observed in time-resolved PL measurements shows good material quality. The steady-state PL peak position exhibits a blue shift with increasing excess carrier concentration. Self-consistent solutions of the Schroedinger and Poisson equations show that this effect can be explained by band bending as a result of the spatial separation of electrons and holes, which is critical confirmation of a strong type-II band edge alignment between CdSe and CdTe.

  15. Fabrication of fluorescent composite with ultrafast aqueous synthesized high luminescent CdTe quantum dots

    SciTech Connect (OSTI)

    Zhang, Lei, E-mail: mejswu@ust.hk; Chen, Haibin, E-mail: mejswu@ust.hk, E-mail: mejswu@ust.hk; Wu, Jingshen, E-mail: mejswu@ust.hk, E-mail: mejswu@ust.hk [Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong and Fok Ying Tung Graduate School, The Hong Kong University of Science and Technology (Hong Kong); Bi, Xianghong, E-mail: takubatch@gmail.com [Fok Ying Tung Graduate School, The Hong Kong University of Science and Technology (Hong Kong)

    2014-05-15

    Without precursor preparation, inert gas protection and enormous amount of additives and reductants, CdTe quantum dots (QDs) can be rapidly synthesized with high quality. A 600 nm photoluminescence peak wavelength could be obtained within 1 hour's refluxing through minimal addition of 1,2-diaminoethane (DAE). The theoretical design for the experiments are illustrated and further proved by the characterization results with different concentrations and reagents. On the other hand, generation of CdTe QDs was found even under room temperature by applying droplet quantity of DAE. This indicates that QDs can be synthesized with simply a bottle and no enormous additives required. The QDs were mixed into the epoxy matrix through solution casting method with cetyltrimethylammonium (CTA) capping for phase transfer. The acquired epoxy based nanocomposite exhibits good transparency, compatibility and fluorescence.

  16. Electronic structure reconstruction across the antiferromagnetic transition in TaFe????Te? spin ladder

    SciTech Connect (OSTI)

    Xu, Min; Wang, Li -Min; Peng, Rui; Ge, Qing -Qin; Chen, Fei; Ye, Zi -Rong; Zhang, Yan; Chen, Su -Di; Xia, Miao; Liu, Rong -Hua; Arita, M.; Shimada, K.; Namatame, H.; Taniguchi, M.; Matsunami, M.; Kimura, S.; Shi, Ming; Chen, Xian -Hui; Yin, Wei -Guo; Ku, Wei; Xie, Bin -Ping; Feng, Dong -Lai

    2015-02-01

    With angle-resolved photoemission spectroscopy, we studied the electronic structure of TaFe????Te?, a two-leg spin ladder compound with a novel antiferromagnetic ground state. Quasi-two-dimensional Fermi surface is observed, with sizable inter-ladder hopping. Moreover, instead of observing an energy gap at the Fermi surface in the antiferromagnetic state, we observed the shifts of various bands. Combining these observations with density-functional-theory calculations, we propose that the large scale reconstruction of the electronic structure, caused by the interactions between coexisting itinerant electrons and local moments, is most likely the driving force of the magnetic transition. Thus TaFe????Te? serves as a simpler platform that contains similar ingredients as the parent compounds of iron-based superconductors.

  17. Higgs mass from compositeness at a multi-TeV scale

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

    Cheng, Hsin -Chia; Dobrescu, Bogdan A.; Gu, Jiayin

    2014-08-18

    Within composite Higgs models based on the top seesaw mechanism, we show that the Higgs field can arise as the pseudo Nambu-Goldstone boson of the broken U(3)more » $$_{L}$$ chiral symmetry associated with a vector-like quark and the t-b doublet. As a result, the lightest CP-even neutral state of the composite scalar sector is lighter than the top quark, and can be identified as the newly discovered Higgs boson. As a result, constraints on weak-isospin violation push the chiral symmetry breaking scale above a few TeV, implying that other composite scalars are probably too heavy to be probed at the LHC, but may be within reach at a future hadron collider with center-of-mass energy of about 100 TeV.« less

  18. The High-Resolution Lightweight Telescope for the EUV (HiLiTE)

    SciTech Connect (OSTI)

    Martinez-Galarce, D S; Boerner, P; Soufli, R; De Pontieu, B; Katz, N; Title, A; Gullikson, E M; Robinson, J C; Baker, S L

    2008-06-02

    The High-resolution Lightweight Telescope for the EUV (HiLiTE) is a Cassegrain telescope that will be made entirely of Silicon Carbide (SiC), optical substrates and metering structure alike. Using multilayer coatings, this instrument will be tuned to operate at the 465 {angstrom} Ne VII emission line, formed in solar transition region plasma at {approx}500,000 K. HiLiTE will have an aperture of 30 cm, angular resolution of {approx}0.2 arc seconds and operate at a cadence of {approx}5 seconds or less, having a mass that is about 1/4 that of one of the 20 cm aperture telescopes on the Atmospheric Imaging Assembly (AIA) instrument aboard NASA's Solar Dynamics Observatory (SDO). This new instrument technology thus serves as a path finder to a post-AIA, Explorer-class missions.

  19. Anti pp searches for quark-gluon plasma at TeV I

    SciTech Connect (OSTI)

    Turkot, F.

    1986-06-01

    Three experiments that have been approved to run at TeV I are discussed from the viewpoint of their capability to search for evidence of the QCD phase transition in proton-antiproton collisions at 1.6 TeV. One of these experiments, E-735, was proposed as a dedicated search for quark-gluon plasma effects with a detector designed to study large total E/sub T/, low P/sub T/ individual particles. The other two, E-741 (CDF) and E-740 (DO), embody general purpose four-pi detectors designed primarily to study the physics of W and Z bosons and other large P/sub T/ phenomena. The detectors and their quark-gluon plasma signals are compared. 8 refs., 6 figs., 4 tabs. (LEW)

  20. Broadening of optical transitions in polycrystalline CdS and CdTe thin films

    SciTech Connect (OSTI)

    Li Jian; Chen Jie; Collins, R. W.

    2010-11-01

    The dielectric functions {epsilon} of polycrystalline CdS and CdTe thin films sputter deposited onto Si wafers were measured from 0.75 to 6.5 eV by in situ spectroscopic ellipsometry. Differences in {epsilon} due to processing variations are well understood using an excited carrier scattering model. For each sample, a carrier mean free path {lambda} is defined that is found to be inversely proportional to the broadening of each of the band structure critical points (CPs) deduced from {epsilon}. The rate at which broadening occurs with {lambda}{sup -1} is different for each CP, enabling a carrier group speed {upsilon}{sub g} to be identified for the CP. With the database for {upsilon}{sub g}, {epsilon} can be analyzed to evaluate the quality of materials used in CdS/CdTe photovoltaic heterojunctions.

  1. Search for new particles decaying to diject in 7 TeV proton-proton collisions at CMS

    SciTech Connect (OSTI)

    Ozturk, Sertac; /Cukurova U.

    2011-03-01

    This thesis presents a measurement of the dijet invariant mass spectrum and search for new particles decaying to dijets at CMS in 7 TeV pp collisions using data corresponding to an integrated luminosity of 2.875 pb{sup -1}. The measured dijet mass distribution is compared to QCD prediction from PYTHIA . It is required the pseudorapidity separation of the two jets to satisfy |Dh| < 1.3 with each jet inside the region of |{eta}| < 2.5. The observed dijet mass spectrum is fitted by a smooth function to search for dijet resonances. Since there is no evidence for dijet resonances, the upper limits at 95% Confidence Level (C.L.) on the resonance cross section are set. These generic cross section limits are compared with theoretical predictions for the cross section for several models of new particles: string resonances, axigluons, colorons, excited quarks, E{sub 6} diquarks, Randall-Sundrum gravitons, W' and Z'. It is excluded at 95% C.L. string resonances in the mass range 0.50 < M(S) < 2.50 TeV, excited quarks in the mass range 0.50 < M(q*) < 1.58 TeV, axigluons and colorons in the mass ranges 0.50 < M(A) < 1.17 TeV and 1.47 < M(A) < 1.52 TeV, and E{sub 6} diquarks in the mass ranges 0.50 < M(D) < 0.58 TeV, 0.97 < M(D) < 1.08 TeV, and 1.45 < M(D) < 1.60 TeV. These exclusions extend previously published limits on all models.

  2. Dijet Azimuthal Decorrelations in pp Collisions at sqrt(s) = 7 TeV

    SciTech Connect (OSTI)

    Khachatryan, Vardan; et al.

    2011-03-01

    Measurements of dijet azimuthal decorrelations in pp collisions at sqrt(s) = 7 TeV using the CMS detector at the CERN LHC are presented. The analysis is based on an inclusive dijet event sample corresponding to an integrated luminosity of 2.9 inverse picobarns. The results are compared to predictions from perturbative QCD calculations and various Monte Carlo event generators. The dijet azimuthal distributions are found to be sensitive to initial-state gluon radiation.

  3. New acceptor centers of the background impurities in p-CdZnTe

    SciTech Connect (OSTI)

    Plyatsko, S. V. Rashkovetskyi, L. V.

    2013-07-15

    Low-temperature photoluminescence data are used to study the redistribution of the background impurities and host components of p-CdZnTe single crystals with a resistivity of 1-50 {Omega} cm upon their interaction with infrared laser radiation. The effect of widening of the band gap and the formation of new acceptor centers in response to laser-stimulated changes in the system of intrinsic defects are established. The activation energy of the new acceptor centers is determined.

  4. CsBi4Te6: A High-Performance Thermoelectric Material for Low-Temperature

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

    Applications | Energy Frontier Research Centers CsBi4Te6: A High-Performance Thermoelectric Material for Low-Temperature Applications Home Author: D.Y. Chung, T. Hogan, P. Brazis, M. Rocci-Lane, C. Kannawurf, M. Bastea, C. Uher, M. Kanatzidis Year: 2000 Abstract: Thermoelectric (Peltier) heat pumps are capable of refrigerating solid or fluid objects, and unlike conventional vapor compressor systems, they can be miniaturized without loss of efficiency. More efficient thermoelectric materials

  5. ETA-HAC07 - Control of Measuring and Test Equipment (M&TE)

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

    7 Revision 0 Effective November 1, 2004 Control of Measuring and Test Equipment (M&TE) Prepared by Electric Transportation Applications Prepared by: _______________________________ Date:__________ Roberta Brayer Approved by: _________________________________________________ Date: _______________ Donald B. Karner Procedure ETA-HAC07 Revision 0 2004 Electric Transportation Applications All Rights Reserved 2 TABLE OF CONTENTS 1.0 Objectives 3 2.0 Purpose 3 3.0 Documentation Support 3 4.0

  6. ETA-HIAC07 - Control of Measuring and Test Equipment (M&TE)

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

    7 Revision 0 Effective May 1, 2004 Control of Measuring and Test Equipment (M&TE) Prepared by Electric Transportation Applications Prepared by: _______________________________ Date:__________ Roberta Brayer Approved by: _________________________________________________ Date: _______________ Donald B. Karner Procedure ETA-HIAC07 Revision 0 2004 Electric Transportation Applications All Rights Reserved 2 TABLE OF CONTENTS 1.0 Objectives 3 2.0 Purpose 3 3.0 Documentation Support 3 4.0 Initial

  7. ETA-NAC007 - Control of Measuring and Test Equipment (M&TE)

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

    7 Revision 0 Effective October 15, 2001 Control of Measuring and Test Equipment (M&TE) Prepared by Electric Transportation Applications Prepared by: _______________________________ Date:__________ Jude M. Clark Approved by: _________________________________________________ Date: _______________ Donald B. Karner Procedure ETA-NAC007 Revision 0 2001 Electric Transportation Applications All Rights Reserved 2 TABLE OF CONTENTS 1.0 Objectives 3 2.0 Purpose 3 3.0 Documentation Support 3 4.0

  8. ETA-UAC07 - Control of Measuring and Test Equipment (M&TE)

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

    7 Revision 0 Effective March 23, 2001 "Control of Measuring and Test Equipment (M&TE)" Prepared by Electric Transportation Applications Prepared by: _______________________________ Date:__________ Jude M. Clark Approved by: _________________________________________________ Date: _______________ Donald B. Karner Procedure ETA-UAC07 Revision 0 ©2001 Electric Transportation Applications All Rights Reserved 2 TABLE OF CONTENTS 1.0 Objectives 3 2.0 Purpose 3 3.0 Documentation Support 3

  9. Topological crystalline insulator Pb{sub x}Sn{sub 1-x}Te thin films on SrTiO{sub 3} (001) with tunable Fermi levels

    SciTech Connect (OSTI)

    Guo, Hua; Liu, Jun-Wei; Wang, Zhen-Yu; Wu, Rui; Ji, Shuai-Hua; Duan, Wen-Hui; Chen, Xi Xue, Qi-Kun; Yan, Chen-Hui; Zhang, Zhi-Dong; Wang, Li-Li; He, Ke; Ma, Xu-Cun

    2014-05-01

    In this letter, we report a systematic study of topological crystalline insulator Pb{sub x}Sn{sub 1-x}Te (0 < x < 1) thin films grown by molecular beam epitaxy on SrTiO{sub 3}(001). Two domains of Pb{sub x}Sn{sub 1-x}Te thin films with intersecting angle of ? ? 45 were confirmed by reflection high energy diffraction, scanning tunneling microscopy, and angle-resolved photoemission spectroscopy (ARPES). ARPES study of Pb{sub x}Sn{sub 1-x}Te thin films demonstrated that the Fermi level of PbTe could be tuned by altering the temperature of substrate whereas SnTe cannot. An M-shaped valance band structure was observed only in SnTe but PbTe is in a topological trivial state with a large gap. In addition, co-evaporation of SnTe and PbTe results in an equivalent variation of Pb concentration as well as the Fermi level of Pb{sub x}Sn{sub 1-x}Te thin films.

  10. Multiwavelength study of the northeastern outskirts of the extended TeV source HESS J1809193

    SciTech Connect (OSTI)

    Rangelov, Blagoy; Kargaltsev, Oleg; Hare, Jeremy; Volkov, Igor; Posselt, Bettina; Pavlov, George G.

    2014-11-20

    HESS J1809193 is an extended TeV ?-ray source in the Galactic plane. Multiwavelength observations of the HESS J1809193 field reveal a complex picture. We present results from three Chandra X-Ray Observatory and two Suzaku observations of a region in the northeastern outskirts of HESS J1809-193, where enhanced TeV emission has been reported. Our analysis also includes GeV ?-ray and radio data. One of the X-ray sources in the field is the X-ray binary XTE J1810-189, for which we present the outburst history from multiple observatories and confirm that XTE J1810-189 is a strongly variable type I X-ray burster, which can hardly produce TeV emission. We investigate whether there is any connection between the possible TeV extension of HESS J1809193 and the sources seen at lower energies. We find that another X-ray binary candidate, Suzaku J1811-1900, and a radio supernova remnant, SNR G11.40.1, can hardly be responsible for the putative TeV emission. Our multiwavelength classification of fainter X-ray point sources also does not produce a plausible candidate. We conclude that the northeast extension of HESS J1809193, if confirmed by deeper observations, can be considered a dark acceleratora TeV source without a visible counterpart at lower energies.

  11. Ultrathin nanosheets of CrSiTe3: A semiconducting two-dimensional ferromagnetic material

    SciTech Connect (OSTI)

    Lin, Ming -Wei; Zhung, Houlong L.; Yan, Jiaqiang; Ward, Thomas Zac; Puretzky, Alexander A.; Rouleau, Christopher M.; Gai, Zheng; Liang, Liangbo; Meunier, Vincent; Ganesh, Panchapakesan; Kent, Paul R. C.; Sumpter, Bobby G.; Mandrus, David G.; Geohegan, David B.; Xiao, Kai

    2015-11-27

    Finite range ferromagnetism and antiferromagnetism in two-dimensional (2D) systems within an isotropic Heisenberg model at non-zero temperature were originally proposed to be impossible. However, recent theoretical studies using an Ising model have recently shown that 2D magnetic crystals can exhibit magnetism. Experimental verification of existing 2D magnetic crystals in this system has remained elusive. In this work we for the first time exfoliate the CrSiTe3, a bulk ferromagnetic semiconductor, to mono- and few-layer 2D crystals onto a Si/SiO2 substrate. The Raman spectra show the good stability and high quality of the exfoliated flakes, consistent with the computed phonon spectra of 2D CrSiTe3, giving a strong evidence for the existence of 2D CrSiTe3 crystals. When the thickness of the CrSiTe3 crystals is reduced to few-layers, we observed a clear change in resistivity at 80~120 K, consistent with the theoretical calculations on the Curie temperature (Tc) of ~80 K for the magnetic ordering of 2D CrSiTe3 crystals. As a result, the ferromagnetic mono- and few-layer 2D CrSiTe3 indicated here should enable numerous applications in nano-spintronics.

  12. Search for resonances and quantum black holes using dijet mass spectra in proton-proton collisions at sqrt(s)=8 TeV

    SciTech Connect (OSTI)

    Khachatryan, V.; et al.,

    2015-03-01

    A search for resonances and quantum black holes is performed using the dijet mass spectra measured in proton-proton collisions at sqrt(s)=8 TeV with the CMS detector at the LHC. The data set corresponds to an integrated luminosity of 19.7 inverse femtobarns. In a search for narrow resonances that couple to quark-quark, quark-gluon, or gluon-gluon pairs, model-independent upper limits, at 95% confidence level, are obtained on the production cross section of resonances, with masses above 1.2 TeV. When interpreted in the context of specific models the limits exclude: string resonances with masses below 5.0 TeV; excited quarks below 3.5 TeV; scalar diquarks below 4.7 TeV; W' bosons below 1.9 TeV or between 2.0 and 2.2 TeV; Z' bosons below 1.7 TeV; and Randall-Sundrum gravitons below 1.6 TeV. A separate search is conducted for narrow resonances that decay to final states including b quarks. The first exclusion limit is set for excited b quarks, with a lower mass limit between 1.2 and 1.6 TeV depending on their decay properties. Searches are also carried out for wide resonances, assuming for the first time width-to-mass ratios up to 30%, and for quantum black holes with a range of model parameters. The wide resonance search excludes axigluons and colorons with mass below 3.6 TeV, and color-octet scalars with mass below 2.5 TeV. Lower bounds between 5.0 and 6.3 TeV are set on the masses of quantum black holes.

  13. Searching for Neutrinoless Double-Beta Decay of130Te with CUORE

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

    Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Balata, M.; Banks, T. I.; Bari, G.; Beeman, J.; Bellini, F.; Bersani, A.; Biassoni, M.; et al

    2015-01-01

    Neutrinoless double-beta (0???) decay is a hypothesized lepton-number-violating process that offers the only known means of asserting the possible Majorana nature of neutrino mass. The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for 0???decay of130Te using an array of 988 TeO2crystal bolometers operated at 10?mK. The detector will contain 206?kg of130Te and have an average energy resolution of 5?keV; the projected 0???decay half-life sensitivity after five years of livetime is 1.6??1026?y at 1?(9.5??1025?y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana massmorein the range 40100?meV (50130?meV). In this paper, we review the experimental techniques used in CUORE as well as its current status and anticipated physics reach.less

  14. Beam extraction from TeV accelerators using channeling in bent crystals

    SciTech Connect (OSTI)

    Carrigan, R.A. Jr.; Toohig, T.E.; Tsyganov, E.N.; Superconducting Super Collider Lab., Dallas, TX; Joint Inst. for Nuclear Research, Dubna )

    1989-08-01

    Bent crystal channeling offers an interesting alternative for beam extraction from trans-GeV accelerators. Conventional extraction employs resonant beam blow-up coupled with electromagnetic beam deflecting channels. It is limited by the length of the available accelerator straight section. Channeling crystals require much less space. A five-step approach to applying crystal extraction in the Superconducting Super Collider (SSC) is discussed. Two steps, extraction from the 8 GeV Dubna Synchrophasotron and the 76 GeV Serpukhov accelerator, have occurred. The next possibility is extraction from a multi-hundred GeV superconducting accelerator. In the nineties the program could continue at UNK (3 TeV) and culminate at the TeV SSC. The possibilities and limitations of crystal extraction are reviewed. More information is needed on dechanneling in bent crystals including the effects of dislocations at TeV energies. Long, dislocation-free'' crystals are required. A more thorough understanding of the theory of crystal extraction is also desirable. 12 refs.

  15. Searching for Neutrinoless Double-Beta Decay of 130 Te with CUORE

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

    Artusa, D. R.; Avignone, F. T.; Azzolini, O.; Balata, M.; Banks, T. I.; Bari, G.; Beeman, J.; Bellini, F.; Bersani, A.; Biassoni, M.; et al

    2015-01-01

    Neumore » trinoless double-beta (0 ν β β ) decay is a hypothesized lepton-number-violating process that offers the only known means of asserting the possible Majorana nature of neutrino mass. The Cryogenic Underground Observatory for Rare Events (CUORE) is an upcoming experiment designed to search for 0 ν β β decay of 130 Te using an array of 988 TeO 2 crystal bolometers operated at 10 mK. The detector will contain 206 kg of 130 Te and have an average energy resolution of 5 keV; the projected 0 ν β β decay half-life sensitivity after five years of livetime is 1.6 × 10 26  y at 1 σ (9.5 × 10 25  y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40–100 meV (50–130 meV). In this paper, we review the experimental techniques used in CUORE as well as its current status and anticipated physics reach.« less

  16. Material and detector properties of cadmium manganese telluride (Cd1-xMnxTe) crystals grown by the modified floating-zone method

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

    Hossain, A.; Gu, G. D.; Bolotnikov, A. E.; Camarda, G. S.; Cui, Y.; Roy, U. N.; Yang, G.; Liu, T.; Zhong, R.; Schneelock, J.; et al

    2014-12-24

    We demonstrated the material- and radiation-detection properties of cadmium manganese telluride (Cd1-xMnxTe; x=0.06), a wide-band-gap semiconductor crystal grown by the modified floating-zone method. We investigated the presence of various bulk defects, such as Te inclusions, twins, and dislocations of several as-grown indium-doped Cd1-xMnxTe crystals using different techniques, viz., IR transmission microscopy, and chemical etching. We then fabricated four planar detectors from selected CdMnTe crystals, characterized their electrical properties, and tested their performance as room-temperature X- and gamma-ray detectors. Thus, our experimental results show that CMT crystals grown by the modified floating zone method apparently are free from Te inclusions. However,more » we still need to optimize our growth parameters to attain high-resistivity, large-volume single-crystal CdMnTe.« less

  17. Search for New Phenomena in Dijet Angular Distributions in Proton-Proton Collisions at s = 8 TeV Measured with the ATLAS Detector

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

    Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Aben, R.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; et al

    2015-06-04

    A search for new phenomena in LHC proton-proton collisions at a center-of-mass energy of √s=8 TeV was performed with the ATLAS detector using an integrated luminosity of 17.3 fb⁻¹. The angular distributions are studied in events with at least two jets; the highest dijet mass observed is 5.5 TeV. All angular distributions are consistent with the predictions of the standard model. In a benchmark model of quark contact interactions, a compositeness scale below 8.1 TeV in a destructive interference scenario and 12.0 TeV in a constructive interference scenario is excluded at 95% C.L.; median expected limits are 8.9 TeV formore » the destructive interference scenario and 14.1 TeV for the constructive interference scenario.« less

  18. Development of CdS/CdTe Tin Film Devices for St. Gobain Coated Glass: Cooperative Research and Development Final Report, CRADA Number CRD-08-317

    SciTech Connect (OSTI)

    Gessert, T.

    2012-04-01

    Research performed at NREL to produce CdS/CdTe devices on St. Gobain coated-glass material to establish a baseline CdS/CdTe device process and determine baseline device performance parameters on St. Gobain material. Performance of these baseline devices compared to similar devices produced by applying the established baseline CdS/CdTe process on alternative St. Gobain coated-glass materials.

  19. Manufacturing Process Optimization to Improve Stability, Yield and Efficiency of CdS/CdTe PV Devices: Final Report, December 2004 - January 2009

    SciTech Connect (OSTI)

    Sampath, W. S.; Enzenroth, A.; Barth, K.

    2009-03-01

    The research by Colorado State University advances the understanding of device stability, efficiency, and process yield for CdTe PV devices.

  20. Final technical report; Mercury Release from Organic matter (OM) and OM-Coated Mineral Surfaces

    SciTech Connect (OSTI)

    Aiken, George

    2014-10-02

    This document is the final technical report for a project designed to address fundamental processes controlling the release of mercury from flood plain soils associated with East Fork Poplar Creek, Tennessee near the U.S. Department of Energy Oak Ridge facility. The report summarizes the activities, findings, presentations, and publications resulting from an award to the U.S. Geological that were part of a larger overall effort including Kathy Nagy (University of Illinois, Chicago, Ill) and Joseph Ryan (University of Colorado, Boulder, CO). The specific charge for the U.S.G.S. portion of the study was to provide analytical support for the larger group effort (Nagy and Ryan), especially with regard to analyses of Hg and dissolved organic matter, and to provide information about the release of mercury from the floodplain soils.

  1. High Resolution Dopant Profiles Revealed by Atom Probe Tomography and STEM-EBIC for CdTe Based Solar Cells

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

    Poplawsky, Jonathan D.; Li, Chen; Paudel, Naba; Guo, Wei; Yan, Yanfa; Pennycook, Stephen J.

    2016-01-01

    Segregated elements and their diffusion profiles within grain boundaries and interfaces resulting from post deposition heat treatments are revealed using atom probe tomography (APT), scanning transmission electron microscopy (STEM), and electron beam induced current (EBIC) techniques. The results demonstrate how these techniques complement each other to provide conclusive evidence for locations of space charge regions and mechanisms that create them at the nanoscale. Most importantly, a Cl dopant profile that extends ~5 nm into CdTe grains interfacing the CdS is shown using APT and STEM synergy, which has been shown to push the pn-junction into the CdTe layer indicative ofmore » a homojunction (revealed by STEM EBIC). In addition, Cu and Cl concentrations within grain boundaries within several nms and µms from the CdS/CdTe interface are compared, Na segregation of <0.1% is detected, and S variations of ~1–3% are witnessed between CdTe grains close to the CdS/CdTe interface. The segregation and diffusion of these elements directly impacts on the material properties, such as band gap energy and n/p type properties. Optimization of the interfacial and grain boundary doping will lead to higher efficiency solar cells.« less

  2. Towards a predictive route for selection of doping elements for the thermoelectric compound PbTe from first-principles

    SciTech Connect (OSTI)

    Joseph, Elad; Amouyal, Yaron

    2015-05-07

    Striving for improvements of the thermoelectric (TE) properties of the technologically important lead telluride (PbTe) compound, we investigate the influence of different doping elements on the thermal conductivity, Seebeck coefficient, and electrical conductivity applying density functional theory calculations. Our approach combines total-energy calculations yielding lattice vibrational properties with the Boltzmann transport theory to obtain electronic transport properties. We find that doping with elements from the 1st and 3rd columns of the periodic table reduces the sound velocity and, consequently, the lattice thermal conductivity, while 2nd column dopants have no such influence. Furthermore, 1.6 at.?% doping with 4th and 5th column elements provides the highest reduction of lattice thermal conductivity. Out of this group, Hf doping results in maximum reduction of the sound velocity from 2030?m s{sup ?1} for pure PbTe to 1370?m s{sup ?1}, which is equivalent to ca. 32% reduction of lattice thermal conductivity. The highest power factor values calculated for 1.6 at.?% doping range between 40 and 56??W cm{sup ?1} K{sup ?2}, and are obtained for substitution with dopants having the same valence as Pb or Te, such as those located at the 2nd, 14th, and 16th columns of the periodic table. We demonstrate how this method may be generalized for dopant-selection-oriented materials design aimed at improving TE performance of other compounds.

  3. Fabrication and Spark plasma sintering of nanostructured bismuth telluride (Bi{sub 2}Te{sub 3})

    SciTech Connect (OSTI)

    Saleemi, Mohsin; Toprak, Muhammet S.; Li, Shanghua; Johnsson, Mats; Muhammed, Mamoun

    2012-06-26

    Thermoelectric (TE) devices can harvest residual low-grade waste heat energy. Bismuth telluride (Bi{sub 2}Te{sub 3}) and its alloys are mostly used TE materials in the bulk form for making TE modules. We report a simple, fast and very high yield synthetic process for the bulk Bi{sub 2}Te{sub 3} nanopowders with hexagonal plate like morphology. Spark plasma sintering (SPS) process has been optimized in order to preserve nanostructure while achieving a high compaction density of the pellets. Electron microscopy analysis was used to determine the effect of SPS parameters during compaction on the grain growth. Optimal conditions for the fabricated nanopowder was determined as 673 K, 70 MPa pressure with no holding time, which resulted in average lateral grain size in the range of 165-190 nm for a compact density of 98%. About 50% reduction of thermal conductivity was observed as compared to its bulk counterparts, revealing the feasibility of suggested route in the preservation of nanostructure and enhanced phonon scattering.

  4. Fermi level pinning in Fe-doped PbTe under pressure

    SciTech Connect (OSTI)

    Skipetrov, E. P. Kruleveckaya, O. V.; Skipetrova, L. A.; Slynko, E. I.; Slynko, V. E.

    2014-07-14

    We synthesize an iron-doped PbTe single-crystal ingot and investigate the phase and the elemental composition as well as galvanomagnetic properties in weak magnetic fields (4.2?K?T?300?K, B???0.07?T) of Pb{sub 1?y}Fe{sub y}Te alloys upon varying the iron content, at atmospheric pressure and under hydrostatic compression up to 10 kilobars. We find an increase of iron concentration along the length of the ingot and the appearance of microscopic inclusions enriched with iron in the heavily doped samples. Lightly doped alloys are characterized by the p-type metal conductivity. An increase of the iron impurity content leads to a decrease in the free hole concentration, a stabilization of galvanomagnetic parameters, indicating the pinning of the Fermi energy by the iron resonant impurity level lying under the bottom of the valence band, and to the p-n inversion of the conductivity type. Under pressure, the free hole concentration in the sample, in which the stabilization of galvanomagnetic parameters takes place, increases by approximately a factor of four due to the flow of electrons from the valence band to the iron-induced resonant level. Using the two-band Kane and the six-band Dimmock dispersion relations, the pressure dependence of the Fermi energy is calculated. The model of the electronic structure rearrangement of Pb{sub 1?y}Fe{sub y}Te under pressure is proposed. The energy position and the pressure coefficient of the resonant iron impurity level are determined.

  5. RAPID TeV GAMMA-RAY FLARING OF BL LACERTAE

    SciTech Connect (OSTI)

    Arlen, T.; Aune, T.; Bouvier, A.; Beilicke, M.; Buckley, J. H.; Bugaev, V.; Dickherber, R.; Benbow, W.; Cesarini, A.; Connolly, M. P.; Ciupik, L.; Cui, W.; Feng, Q.; Finley, J. P.; Dumm, J.; Fortson, L.; Errando, M.; Falcone, A.; Federici, S.; Finnegan, G. E-mail: cui@purdue.edu; Collaboration: VERITAS Collaboration; and others

    2013-01-10

    We report on the detection of a very rapid TeV gamma-ray flare from BL Lacertae on 2011 June 28 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The flaring activity was observed during a 34.6 minute exposure, when the integral flux above 200 GeV reached (3.4 {+-} 0.6) Multiplication-Sign 10{sup -6} photons m{sup -2} s{sup -1}, roughly 125% of the Crab Nebula flux measured by VERITAS. The light curve indicates that the observations missed the rising phase of the flare but covered a significant portion of the decaying phase. The exponential decay time was determined to be 13 {+-} 4 minutes, making it one of the most rapid gamma-ray flares seen from a TeV blazar. The gamma-ray spectrum of BL Lacertae during the flare was soft, with a photon index of 3.6 {+-} 0.4, which is in agreement with the measurement made previously by MAGIC in a lower flaring state. Contemporaneous radio observations of the source with the Very Long Baseline Array revealed the emergence of a new, superluminal component from the core around the time of the TeV gamma-ray flare, accompanied by changes in the optical polarization angle. Changes in flux also appear to have occurred at optical, UV, and GeV gamma-ray wavelengths at the time of the flare, although they are difficult to quantify precisely due to sparse coverage. A strong flare was seen at radio wavelengths roughly four months later, which might be related to the gamma-ray flaring activities. We discuss the implications of these multiwavelength results.

  6. Experimental investigation of spin-orbit coupling in n-type PbTe quantum wells

    SciTech Connect (OSTI)

    Peres, M. L.; Monteiro, H. S.; Castro, S. de; Chitta, V. A.; Oliveira, N. F.; Mengui, U. A.; Rappl, P. H. O.; Abramof, E.; Maude, D. K.

    2014-03-07

    The spin-orbit coupling is studied experimentally in two PbTe quantum wells by means of weak antilocalization effect. Using the Hikami-Larkin-Nagaoka model through a computational global optimization procedure, we extracted the spin-orbit and inelastic scattering times and estimated the strength of the zero field spin-splitting energy ?{sub so}. The values of ?{sub so} are linearly dependent on the Fermi wave vector (k{sub F}) confirming theoretical predictions of the existence of large spin-orbit coupling in IV-VI quantum wells originated from pure Rashba effect.

  7. Ab initio study of the structural, electronic and optical properties of ZnTe compound

    SciTech Connect (OSTI)

    Bahloul, B.; Deghfel, B.; Amirouche, L.; Bounab, S.; Bentabet, A.; Bouhadda, Y.; Fenineche, N.

    2015-03-30

    Structural, electronic and optical properties of ZnTe compound were calculated using Density Functional Theory (DFT) based on the pseudopotentials and planewaves (PP-PW) method as implemented in the ABINIT computer code, where the exchangecorrelation functional is approximated using the local density approximation (LDA) and the generalized gradient approximation (GGA). The obtained results from either LDA or GGa calculation for lattice parameter, energy band gap and optical parameters, such as the fundamental absorption edge, the peaks observed in the imaginary part of the dielectric function, the macroscopic dielectric constants and the optical dielectric constant, are compared with the available theoretical results and experimental data.

  8. TeV-scale gauged B-L symmetry with inverse seesaw mechanism

    SciTech Connect (OSTI)

    Khalil, Shaaban

    2010-10-01

    We propose a modified version of the TeV-scale B-L extension of the standard model, where neutrino masses are generated through the inverse seesaw mechanism. We show that heavy neutrinos in this model can be accessible via clean signals at the LHC. The search for the extra gauge boson Z{sub B-L}{sup '} through the decay into dileptons or two dileptons plus missing energy is studied. We also show that the B-L extra Higgs boson can be directly probed at the LHC via a clean dilepton and missing energy signal.

  9. Charge ordering in stoichiometric FeTe: Scanning tunneling microscopy and spectroscopy

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

    Li, Wei; Yin, Wei -Guo; Wang, Lili; He, Ke; Ma, Xucun; Xue, Qi -Kun; Chen, Xi

    2016-01-04

    In this study, we use scanning tunneling microscopy and spectroscopy to reveal a unique stripy charge order in a parent phase of iron-based superconductors in stoichiometric FeTe epitaxy films. The charge order has unusually the same—usually half—period as the spin order. We also found highly anisotropic electron band dispersions being large and little along the ferromagnetic (crystallographic b) and antiferromagnetic (a) directions, respectively. Our data suggest that the microscopic mechanism is likely of the Stoner type driven by interatomic Coulomb repulsion Vij, and that Vij and charge fluctuations, so far much neglected, are important to the understanding of iron-based superconductors.

  10. Quantum Hall effect in HgTe quantum wells at nitrogen temperatures

    SciTech Connect (OSTI)

    Kozlov, D. A. Kvon, Z. D.; Mikhailov, N. N.; Dvoretskii, S. A.; Weishupl, S.; Krupko, Y.; Portal, J.-C.

    2014-09-29

    We report on the observation of quantized Hall plateaus in a system of two-dimensional Dirac fermions, implemented in a 6.6?nm HgTe quantum well at magnetic fields up to 34?T at nitrogen temperatures. The activation energies determined from the temperature dependence of the longitudinal resistivity are found to be almost equal for the filling factors ? of 1 and 2. This indicates that the large values of the g-factor (about 3040) remain unchanged at very strong magnetic fields.

  11. Core-shell ITO/ZnO/CdS/CdTe nanowire solar cells

    SciTech Connect (OSTI)

    Williams, B. L.; Phillips, L.; Major, J. D.; Durose, K.; Taylor, A. A.; Mendis, B. G.; Bowen, L.

    2014-02-03

    Radial p-n junction nanowire (NW) solar cells with high densities of CdTe NWs coated with indium tin oxide (ITO)/ZnO/CdS triple shells were grown with excellent heterointerfaces. The optical reflectance of the devices was lower than for equivalent planar films by a factor of 100. The best efficiency for the NW solar cells was ??=?2.49%, with current transport being dominated by recombination, and the conversion efficiencies being limited by a back contact barrier (?{sub B}?=?0.52?eV) and low shunt resistances (R{sub SH}?

  12. Nanoscale structure in AgSbTe2 determined by diffuse elastic neutron scattering

    SciTech Connect (OSTI)

    Specht, Eliot D [ORNL; Ma, Jie [ORNL; Delaire, Olivier A [ORNL; Budai, John D [ORNL; May, Andrew F [ORNL; Karapetrova, Evguenia A. [Argonne National Laboratory (ANL)

    2015-01-01

    Diffuse elastic neutron scattering measurements confirm that AgSbTe2 has a hierarchical structure, with defects on length scales from nanometers to microns. While scattering from mesoscale structure is consistent with previously-proposed structures in which Ag and Sb order on a NaCl lattice, more diffuse scattering from nanoscale structure suggests a structural rearrangement in which hexagonal layers form a combination of (ABC), (ABA), and (AAB) stacking sequences. The AgCrSe2 structure is the best-fitting model for the local atomic arrangements.

  13. Quantum Anomalous Hall Effect in Hg_1-yMn_yTe Quantum Wells

    SciTech Connect (OSTI)

    Liu, Chao-Xing; Qi, Xiao-Liang; Dai, Xi; Fang, Zhong; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.

    2010-03-19

    The quantum Hall effect is usually observed when the two-dimensional electron gas is subjected to an external magnetic field, so that their quantum states form Landau levels. In this work we predict that a new phenomenon, the quantum anomalous Hall effect, can be realized in Hg{sub 1-y}Mn{sub y}Te quantum wells, without the external magnetic field and the associated Landau levels. This effect arises purely from the spin polarization of the Mn atoms, and the quantized Hall conductance is predicted for a range of quantum well thickness and the concentration of the Mn atoms. This effect enables dissipationless charge current in spintronics devices.

  14. Heavy Higgs bosons and the 2 TeV $W'$ boson

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

    Dobrescu, Bogdan A.; Liu, Zhen

    2015-10-19

    The hints from the LHC for the existence of a W' boson of mass around 1.9 TeV point towards a certain SU(2) L × SU(2) R × U(1) B-L gauge theory with an extended Higgs sector. We show that the decays of the W' boson into heavy Higgs bosons have sizable branching fractions. Interpreting the ATLAS excess events in the search for same-sign lepton pairs plus b jets as arising from W' cascade decays, we then estimate that the masses of the heavy Higgs bosons are in the 400-700 GeV range.

  15. Conductive atomic force microscopy study of local electronic transport in ZnTe thin films

    SciTech Connect (OSTI)

    Kshirsagar, Sachin D.; Krishna, M. Ghanashyam; Tewari, Surya P.

    2013-02-05

    ZnTe thin films obtained by the electron beam evaporation technique were subjected to thermal annealing at 500 Degree-Sign C for 2 hours. The as deposited films were amorphous but transformed to the crystalline state under influence of the thermal treatment. There is increase in optical absorption due to the heat treatment caused by increase in free carrier concentration. Conductive atomic force microscopy shows the presence of electronic inhomogeneities in the films. This is attributed to local compositional variations in the films. I-V analysis in these systems indicates formation of Schottky junction at the metal semiconductor (M-S) interface.

  16. Microstructures, magnetic and electric properties of diluted magnetic semiconductors InTe{sub 1?x} Fe{sub x} (Co{sub x})

    SciTech Connect (OSTI)

    El-Sayed, Karimat; Sedeek, K.; Heiba, Z.K.; Hantour, H.H.

    2013-06-01

    Highlights: ? The prepared InTe{sub 0.9}Fe{sub 0.1} was found to be ferromagnetic at room temperature and can be characterized as diluted magnetic semiconductors. ? The presence of staking faults, various types of defects, strained lattice, grain boundaries and the impurity of minor non-magnetic phase were suggested to participate in high temperature ferromagnetism. - Abstract: InTe compound doped by 10% of Fe or Co respectively was synthesized. X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), energy dispersive X-ray (EDX), vibrating sample magnetometer (VSM) and Kiethley electrometer were used for characterizing the prepared samples. XRD show the presence of InTe{sub 0.9}Fe{sub 0.1} or InTe{sub 0.9}Co{sub 0.1} together with minor In{sub 4}Te{sub 3} phase. InTe{sub 0.9}Fe{sub 0.1} is ferromagnetic with high Curie and high blocking temperature, while InTe{sub 0.9}Co{sub 0.1} is antiferromagnetic with two high Neels temperatures. ?RT of InTe{sub 0.9}Fe{sub 0.1} and InTe{sub 0.9}Co{sub 0.1} are greater than those of InTe. The higher conductivity is due to the higher carrier's density obtained from the interaction of the sp-d orbitals, of the electric and magnetic system. The presence of In{sub 4}Te{sub 3} minor phase and different kinds of defects are taking major roles in the formation of high Tc ferromagnetism and antiferromagnetism.

  17. Search for Quark Compositeness with the Dijet Centrality Ratio in $pp$ Collisions at $\\sqrt{s}=7$ TeV

    SciTech Connect (OSTI)

    Khachatryan, Vardan; et al.

    2010-12-01

    A search for quark compositeness in the form of quark contact interactions, based on hadronic jet pairs (dijets) produced in proton-proton collisions at sqrt(s)=7 TeV, is described. The data sample of the study corresponds to an integrated luminosity of 2.9 inverse picobarns collected with the CMS detector at the LHC. The dijet centrality ratio, which quantifies the angular distribution of the dijets, is measured as a function of the invariant mass of the dijet system and is found to agree with the predictions of the Standard Model. A statistical analysis of the data provides a lower limit on the energy scale of quark contact interactions. The sensitivity of the analysis is such that the expected limit is 2.9 TeV; because the observed value of the centrality ratio at high invariant mass is below the expectation, the observed limit is 4.0 TeV at the 95% confidence level.

  18. Reduction of surface leakage current by surface passivation of CdZn Te and other materials using hyperthermal oxygen atoms

    DOE Patents [OSTI]

    Hoffbauer, Mark A. (Los Alamos, NM); Prettyman, Thomas H. (Los Alamos, NM)

    2001-01-01

    Reduction of surface leakage current by surface passivation of Cd.sub.1-x Zn.sub.x Te and other materials using hyperthermal oxygen atoms. Surface effects are important in the performance of CdZnTe room-temperature radiation detectors used as spectrometers since the dark current is often dominated by surface leakage. A process using high-kinetic-energy, neutral oxygen atoms (.about.3 eV) to treat the surface of CdZnTe detectors at or near ambient temperatures is described. Improvements in detector performance include significantly reduced leakage current which results in lower detector noise and greater energy resolution for radiation measurements of gamma- and X-rays, thereby increasing the accuracy and sensitivity of measurements of radionuclides having complex gamma-ray spectra, including special nuclear materials.

  19. Structural characterization and novel optical properties of defect chalcopyrite ZnGa{sub 2}Te{sub 4} thin films

    SciTech Connect (OSTI)

    Fouad, S.S.; Sakr, G.B.; Yahia, I.S.; Basset, D.M. Abdel

    2011-11-15

    Highlights: {yields} Preparation and characterization of ZnGa{sub 2}Te{sub 4} in powder and thin film forms. {yields} Structure properties such as XRD and EDX. {yields} Optical constant of the as-deposited ZnGa{sub 2}Te{sub 4} for the first time. {yields} Extraction of the optical parameters of the studied films. -- Abstract: Stoichiometric thin film samples of the ternary ZnGa{sub 2}Te{sub 4} defect chalcopyrite compound were prepared and characterized by X-ray diffraction technique. The elemental chemical composition of the prepared bulk material as well as of the as-deposited film was determined by energy-dispersive X-ray spectrometry. ZnGa{sub 2}Te{sub 4} thin films were deposited, by conventional thermal evaporation technique onto highly cleaned glass substrates. The X-ray and electron diffraction studies revealed that the as-deposited and the annealed ZnGa{sub 2}Te{sub 4} films at annealing temperature t{sub a} {<=} 548 K are amorphous, while those annealed at t{sub a} {>=} 573 K (for 1 h), are polycrystalline. The optical properties of the as-deposited films have been investigated for the first time at normal incidence in the spectral range from 500 to 2500 nm. The refractive index dispersion in the transmission and low absorption region is adequately described by the Wemple-DiDomenico single oscillator model, whereby, the values of the oscillator parameters have been calculated. The analysis of the optical absorption coefficient revealed an in-direct optical transition with energy of 1.33 eV for the as-deposited sample. This work suggested that ZnGa{sub 2}Te{sub 4} is a good candidate in solar cell devices as an absorbing layer.

  20. Nanosecond laser-induced phase transitions in pulsed laser deposition-deposited GeTe films

    SciTech Connect (OSTI)

    Sun, Xinxing, E-mail: xinxing.sun@iom-leipzig.de; Thelander, Erik; Lorenz, Pierre; Gerlach, Jrgen W.; Decker, Ulrich; Rauschenbach, Bernd [Leibniz Institute of Surface Modification, Permoserstr. 15, D-04318, Leipzig (Germany)

    2014-10-07

    Phase transformations between amorphous and crystalline states induced by irradiation of pulsed laser deposition grown GeTe thin films with nanosecond laser pulses at 248 nm and pulse duration of 20 ns are studied. Structural and optical properties of the Ge-Te phase-change films were studied by X-ray diffraction and optical reflectivity measurements as a function of the number of laser pulses between 0 and 30 pulses and of the laser fluence up to 195 mJ/cm. A reversible phase transition by using pulse numbers ? 5 at a fluence above the threshold fluence between 11 and 14 mJ/cm for crystallization and single pulses at a fluence between 162 and 182 mJ/cm for amorphization could be proved. For laser fluences from 36 up to 130 mJ/cm, a high optical contrast of 14.7% between the amorphous and crystalline state is measured. A simple model is used that allows the discussion on the distribution of temperature in dependency on the laser fluence.

  1. Nanoscale imaging of photocurrent and efficiency in CdTe solar cells

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

    Leite, Marina S.; National Inst. of Standards and Technology; Abashin, Maxim; National Inst. of Standards and Technology; Lezec, Henri J.; Gianfrancesco, Anthony; Talin, A. Alec; Sandia National Lab.; Zhitenev, Nikolai B.

    2014-10-15

    The local collection characteristics of grain interiors and grain boundaries in thin film CdTe polycrystalline solar cells are investigated using scanning photocurrent microscopy. The carriers are locally generated by light injected through a small aperture (50-300 nm) of a near-field scanning optical microscope in an illumination mode. Possible influence of rough surface topography on light coupling is examined and eliminated by sculpting smooth wedges on the granular CdTe surface. By varying the wavelength of light, nanoscale spatial variations in external quantum efficiency are mapped. We find that the grain boundaries (GBs) are better current collectors than the grain interiors (GIs).more » The increased collection efficiency is caused by two distinct effects associated with the material composition of GBs. First, GBs are charged, and the corresponding built-in field facilitates the separation and the extraction of the photogenerated carriers. Second, the GB regions generate more photocurrent at long wavelength corresponding to the band edge, which can be caused by a smaller local band gap. As a result, resolving carrier collection with nanoscale resolution in solar cell materials is crucial for optimizing the polycrystalline device performance through appropriate thermal processing and passivation of defect and surfaces.« less

  2. The search for TeV-scale dark matter with the HAWC observatory

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

    Harding, J. Patrick

    2015-01-01

    The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to 100 GeV - 100 TeV gamma rays and cosmic rays. Located at an elevation of 4100 m on the Sierra Negra mountain in Mexico, HAWC observes extensive air showers from gamma and cosmic rays with an array of water tanks which produce Cherenkov light in the presence of air showers. With a field-of-view capable of observing 2/3 of the sky each day, and a sensitivity of 1 Crab/day, HAWC will be able to map out the sky in gamma and cosmic rays in detail. In thismore » paper, we discuss the capabilities of HAWC to map out the directions and spectra of TeV gamma rays and cosmic rays coming from sources of dark matter annihilation. We discuss the HAWC sensitivity to multiple extended sources of dark matter annihilation and the possibility of HAWC observations of annihilations in nearby dark matter subhalos.« less

  3. Measurement of the atmospheric muon charge ratio at TeV energies with MINOS

    SciTech Connect (OSTI)

    Adamson, P.; Andreopoulos, C.; Arms, K.E.; Armstrong, R.; Auty, D.J.; Avvakumov, S.; Ayres, D.S.; Baller, B.; Barish, B.; Barnes, P.D., Jr.; Barr, G.; /Fermilab /University Coll. London /Rutherford /Minnesota U. /Indiana U. /Sussex U. /Stanford U., Phys. Dept. /Argonne /Caltech /LLNL, Livermore /Oxford U.

    2007-05-01

    The 5.4 kton MINOS far detector has been taking charge-separated cosmic ray muon data since the beginning of August, 2003 at a depth of 2070 m.w.e. in the Soudan Underground Laboratory, Minnesota, USA. The data with both forward and reversed magnetic field running configurations were combined to minimize systematic errors in the determination of the underground muon charge ratio. When averaged, two independent analyses find the charge ratio underground to be N{sub {mu}}+/N{sub {mu}}-=1.374{+-}0.004(stat)-0.010{sup +0.012}(sys). Using the map of the Soudan rock overburden, the muon momenta as measured underground were projected to the corresponding values at the surface in the energy range 1-7 TeV. Within this range of energies at the surface, the MINOS data are consistent with the charge ratio being energy independent at the 2 standard deviation level. When the MINOS results are compared with measurements at lower energies, a clear rise in the charge ratio in the energy range 0.3-1.0 TeV is apparent. A qualitative model shows that the rise is consistent with an increasing contribution of kaon decays to the muon charge ratio.

  4. Experimental observation of spin-dependent electron many-body effects in CdTe

    SciTech Connect (OSTI)

    Horodysk, P.; N?mec, P. Novotn, T.; Trojnek, F.; Mal, P.

    2014-08-07

    In semiconductors, the spin degree of freedom is usually disregarded in the theoretical treatment of electron many-body effects such as band-gap renormalization and screening of the Coulomb enhancement factor. Nevertheless, as was observed experimentally in GaAs, not only the single-particle phase-space filling but also many-body effects are spin sensitive. In this paper, we report on time- and polarization-resolved differential transmission pump-probe measurements in CdTe, which has the same zincblende crystal structure but different material parameters compared to that of GaAs. We show experimentally that at room temperature in CdTeunlike in GaAsthe pump-induced decrease of transmission due to the band-gap renormalization can even exceed the transmission increase due to the phase-space filling, which enables to measure directly the spin-sensitivity of the band-gap renormalization. We also observed that the influence of the band-gap renormalization is more prominent at low temperatures.

  5. Study of the effect of the stress on CdTe nuclear detectors

    SciTech Connect (OSTI)

    Ayoub, M.; Radley, I.; Mullins, J. T.; Hage-Ali, M.

    2013-09-14

    CdTe detectors are commonly used for X and ? ray applications. The performance of these detectors is strongly affected by different types of mechanical stress; such as that caused by differential expansion between the semiconductor and its intimate metallic contacts and that caused by applied pressure during the bonding process. The aim of this work was to study the effects of stress on the performance of CdTe detectors. A difference in expansion coefficients induces transverse stress under the metallic contact, while contact pressure induces longitudinal stress. These stresses have been simulated by applying known static pressures. For the longitudinal case, the pressure was applied directly to the metallic contact; while in the transverse case, it was applied to the side. We have studied the effect of longitudinal and transverse stresses on the electrical characteristics including leakage current measurements and ?-ray detection performance. We have also investigated induced defects, their nature, activation energies, cross sections, and concentrations under the applied stress by using photo-induced current transient spectroscopy and thermoelectric effect spectroscopy techniques. The operational stress limit is also given.

  6. Magnetic Correlations in the Quasi-2D Semiconducting Ferromagnet CrSiTe3

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

    Williams, Travis J.; Aczel, Adam A.; Lumsden, Mark D.; Nagler, Stephen E.; Stone, Matthew B.; Yan, Jiaqiang; Mandrus, D.

    2015-10-02

    Intrinsic, two-dimensional ferromagnetic semiconductors are an important class of materials for overcoming the limitations of dilute magnetic semiconductors for spintronics applications. CrSiTe3 is a particularly interesting member of this class, since it can likely be exfoliated down to single layers, where Tc is predicted to increase dramatically. Establishing the nature of the magnetism in the bulk is a necessary precursor to understanding the magnetic behavior in thin film samples and the possible applications of this material. In this work, we use elastic and inelastic neutron scattering to measure the magnetic properties of single crystalline CrSiTe3. We find that there ismorea very small single ion anisotropy favoring magnetic ordering along the c-axis and that the measured spin waves fit well to a model where the moments are only weakly coupled along that direction. Finally, we find that both static and dynamic correlations persist within the ab-plane up to at least 300 K, strong evidence of this material's two-dimensional characteristics that are relevant for future studies on thin film and monolayer samples.less

  7. Magnetic Correlations in the Quasi-Two-Dimensional Semiconducting Ferromagnet CrSiTe3

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

    Williams, Travis J.; Aczel, Adam A.; Lumsden, Mark D.; Nagler, Stephen E.; Stone, Matthew B.; Yan, Jiaqiang -Q.; Mandrus, D.

    2015-10-02

    Intrinsic, 2D ferromagnetic semiconductors are an important class of materials for overcoming dilute magnetic semiconductors’ limitations for spintronics. CrSiTe3 is a particularly interesting material of this class, since it can likely be exfoliated to single layers, for which Tc is predicted to increase dramatically. Establishing the nature of the bulk material’s magnetism is necessary for understanding the thin-film magnetic behavior and the material’s possible applications. In this work, we use elastic and inelastic neutron scattering to measure the magnetic properties of single crystalline CrSiTe3. We find a very small single ion anisotropy that favors magnetic ordering along the c-axis andmore » that the measured spin waves fit well to a model in which the moments are only weakly coupled along that direction. Then, we find that both static and dynamic correlations persist within the ab-plane up to at least 300 K, which is strong evidence of the material's 2D characteristics that are relevant for future studies on thin film and monolayer samples.« less

  8. Search for excited leptons in proton-proton collisions at ?(s) = 8 TeV

    SciTech Connect (OSTI)

    Khachatryan, Vardan

    2015-11-05

    Our search for compositeness of electrons and muons is presented using a data sample of proton-proton collisions at a center-of-mass energy of ?(s) = 8 TeV collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 19.7 fb-1. Excited leptons (?*) produced via contact interactions in conjunction with a standard model lepton are considered, and a search is made for their gauge decay modes. The decays considered are ?* ??? and ?* ? ?Z, which give final states of two leptons and a photon or, depending on the Z-boson decay mode, four leptons or two leptons and two jets. The number of events observed in data is consistent with the standard model prediction. Exclusion limits are set on the excited lepton mass, and the compositeness scale L. For the case M?* = L the existence of excited electrons (muons) is excluded up to masses of 2.45 (2.47) TeV at 95% confidence level. The neutral current decays of excited leptons are considered for the first time, and limits are extended to include the possibility that the weight factors f and f ', which determine the couplings between standard model leptons and excited leptons via gauge mediated interactions, have opposite sign.

  9. Local-moment magnetism in superconducting FeTe0.35Se0.65 as seen via

    Office of Scientific and Technical Information (OSTI)

    inelastic neutron scattering (Journal Article) | DOE PAGES Local-moment magnetism in superconducting FeTe0.35Se0.65 as seen via inelastic neutron scattering « Prev Next » Title: Local-moment magnetism in superconducting FeTe0.35Se0.65 as seen via inelastic neutron scattering Authors: Xu, Zhijun ; Wen, Jinsheng ; Xu, Guangyong ; Chi, Songxue ; Ku, Wei ; Gu, Genda ; Tranquada, J. M. Publication Date: 2011-08-11 OSTI Identifier: 1100533 Type: Publisher's Accepted Manuscript Journal Name:

  10. Direct Analysis of JV-Curves Applied to an Outdoor-Degrading CdTe Module (Presentation)

    SciTech Connect (OSTI)

    Jordan, D; Kurtz, S.; Ulbrich, C.; Gerber, A.; Rau, U.

    2014-03-01

    We present the application of a phenomenological four parameter equation to fit and analyze regularly measured current density-voltage JV curves of a CdTe module during 2.5 years of outdoor operation. The parameters are physically meaningful, i.e. the short circuit current density Jsc, open circuit voltage Voc and differential resistances Rsc, and Roc. For the chosen module, the fill factor FF degradation overweighs the degradation of Jsc and Voc. Interestingly, with outdoor exposure, not only the conductance at short circuit, Gsc, increases but also the Gsc(Jsc)-dependence. This is well explained with an increase in voltage dependent charge carrier collection in CdTe.

  11. Cross-Sectional Conductive Atomic Force Microscopy of CdTe/CdS Solar Cells: Effects of Etching and Back-Contact Processes; Preprint

    SciTech Connect (OSTI)

    Moutinho, H. R.; Dhere, R. G.; Jiang, C.-S.; Gessert, T. A.; Duda, A. M.; Young, M.; Metzger, W. K.; Li, X.; Al-Jassim, M. M.

    2006-05-01

    We investigated the effects of the etching processes using bromine and nitric-phosphoric acid solutions, as well as of Cu, in the bulk electrical conductivity of CdTe/CdS solar cells using conductive atomic force microscopy (C-AFM). Although the etching process can create a conductive layer on the surface of the CdTe, the layer is very shallow. In contrast, the addition of a thin layer of Cu to the surface creates a conductive layer inside the CdTe that is not uniform in depth, is concentrated at grains boundaries, and may short circuit the device if the CdTe is too thin. The etching process facilitates the Cu diffusion and results in thicker conductive layers. The existence of this inhomogeneous conductive layer directly affects the current transport and is probably the reason for needing thick CdTe in these devices.

  12. Search for contact interactions and large extra dimensions in the dilepton channel using protonproton collisions at ?s = 8TeV with the ATLAS detector

    SciTech Connect (OSTI)

    Aad, G.

    2014-12-11

    Research is conducted for non-resonant new phenomena in dielectron and dimuon final states, originating from either contact interactions or large extra spatial dimensions. The LHC 2012 protonproton collision dataset recorded by the ATLAS detector is used, corresponding to 20 fb1 at ?s = 8 TeV. The dilepton invariant mass spectrum is a discriminating variable in both searches, with the contact interaction search additionally utilizing the dilepton forward-backward asymmetry. No significant deviations from the Standard Model expectation are observed. Lower limits are set on the ??qq contact interaction scale ? between 15.4 TeV and 26.3 TeV, at the 95% credibility level. For large extra spatial dimensions, lower limits are set on the string scale MS between 3.2 TeV to 5.0 TeV.

  13. Evaluation of a CdTe semiconductor based compact gamma camera for sentinel lymph node imaging

    SciTech Connect (OSTI)

    Russo, Paolo; Curion, Assunta S.; Mettivier, Giovanni; Esposito, Michela; Aurilio, Michela; Caraco, Corradina; Aloj, Luigi; Lastoria, Secondo

    2011-03-15

    Purpose: The authors assembled a prototype compact gamma-ray imaging probe (MediPROBE) for sentinel lymph node (SLN) localization. This probe is based on a semiconductor pixel detector. Its basic performance was assessed in the laboratory and clinically in comparison with a conventional gamma camera. Methods: The room-temperature CdTe pixel detector (1 mm thick) has 256x256 square pixels arranged with a 55 {mu}m pitch (sensitive area 14.08x14.08 mm{sup 2}), coupled pixel-by-pixel via bump-bonding to the Medipix2 photon-counting readout CMOS integrated circuit. The imaging probe is equipped with a set of three interchangeable knife-edge pinhole collimators (0.94, 1.2, or 2.1 mm effective diameter at 140 keV) and its focal distance can be regulated in order to set a given field of view (FOV). A typical FOV of 70 mm at 50 mm skin-to-collimator distance corresponds to a minification factor 1:5. The detector is operated at a single low-energy threshold of about 20 keV. Results: For {sup 99m}Tc, at 50 mm distance, a background-subtracted sensitivity of 6.5x10{sup -3} cps/kBq and a system spatial resolution of 5.5 mm FWHM were obtained for the 0.94 mm pinhole; corresponding values for the 2.1 mm pinhole were 3.3x10{sup -2} cps/kBq and 12.6 mm. The dark count rate was 0.71 cps. Clinical images in three patients with melanoma indicate detection of the SLNs with acquisition times between 60 and 410 s with an injected activity of 26 MBq {sup 99m}Tc and prior localization with standard gamma camera lymphoscintigraphy. Conclusions: The laboratory performance of this imaging probe is limited by the pinhole collimator performance and the necessity of working in minification due to the limited detector size. However, in clinical operative conditions, the CdTe imaging probe was effective in detecting SLNs with adequate resolution and an acceptable sensitivity. Sensitivity is expected to improve with the future availability of a larger CdTe detector permitting operation at shorter distances from the patient skin.

  14. Correlation between the electronic structures and diffusion paths of interstitial defects in semiconductors: The case in CdTe

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

    Ma, Jie; Yang, Jihui; Da Silva, J. L.F.; Wei, Su-Huai

    2014-10-30

    Using first-principles calculations, we study the diffusions of interstitial defects Cd, Cu, Te, and Cl in CdTe. We find that the diffusion behavior is strongly correlated with the electronic structure of the interstitial diffuser. For Cd and Cu, because the defect state is the non-degenerated slike state under Td symmetry, the diffusions are almost along the [111] directions between the tetrahedral sites, although the diffusion of Cu shows some deviation due to the s - d coupling. The diffusions of the neutral and charged Cd and Cu follow similar paths. However, for Te and Cl atoms, because the defect statemore » is the degenerated p-like state under Td symmetry, large distortions occur. Therefore, the diffusion paths are very different from those of Cd and Cu interstitials, and depend strongly on the charge states of the interstitial atoms. For Te, we find that the distortion is mostly stabilized by the crystal-field splitting, but for Cl, the exchange splitting plays a more important role.« less

  15. First Measurement of Hadronic Event Shapes in pp Collisions at sqrt(s)=7 TeV

    SciTech Connect (OSTI)

    Khachatryan, Vardan; et al.

    2011-05-01

    Hadronic event shapes have been measured in proton-proton collisions at sqrt(s)=7 TeV, with a data sample collected with the CMS detector at the LHC. The sample corresponds to an integrated luminosity of 3.2 inverse picobarns. Event-shape distributions, corrected for detector response, are compared with five models of QCD multijet production.

  16. Correlation between the electronic structures and diffusion paths of interstitial defects in semiconductors: The case in CdTe

    SciTech Connect (OSTI)

    Ma, Jie; Yang, Jihui; Da Silva, J. L.F.; Wei, Su-Huai

    2014-10-30

    Using first-principles calculations, we study the diffusions of interstitial defects Cd, Cu, Te, and Cl in CdTe. We find that the diffusion behavior is strongly correlated with the electronic structure of the interstitial diffuser. For Cd and Cu, because the defect state is the non-degenerated slike state under Td symmetry, the diffusions are almost along the [111] directions between the tetrahedral sites, although the diffusion of Cu shows some deviation due to the s - d coupling. The diffusions of the neutral and charged Cd and Cu follow similar paths. However, for Te and Cl atoms, because the defect state is the degenerated p-like state under Td symmetry, large distortions occur. Therefore, the diffusion paths are very different from those of Cd and Cu interstitials, and depend strongly on the charge states of the interstitial atoms. For Te, we find that the distortion is mostly stabilized by the crystal-field splitting, but for Cl, the exchange splitting plays a more important role.

  17. A measurement of the 2 neutrino double beta decay rate of Te-130 in the CUORICINO experiment

    SciTech Connect (OSTI)

    Kogler, Laura

    2011-11-03

    CUORICINO was a cryogenic bolometer experiment designed to search for neutrinoless double beta decay and other rare processes, including double beta decay with two neutrinos (2{nu}{beta}{beta}). The experiment was located at Laboratori Nazionali del Gran Sasso and ran for a period of about 5 years, from 2003 to 2008. The detector consisted of an array of 62 TeO{sub 2} crystals arranged in a tower and operated at a temperature of #24;10 mK. Events depositing energy in the detectors, such as radioactive decays or impinging particles, produced thermal pulses in the crystals which were read out using sensitive thermistors. The experiment included 4 enriched crystals, 2 enriched with {sup 130}Te and 2 with {sup 128}Te, in order to aid in the measurement of the 2{nu}{beta}{beta} rate. The enriched crystals contained a total of #24;350 g {sup 130}Te. The 128-enriched (130-depleted) crystals were used as background monitors, so that the shared backgrounds could be subtracted from the energy spectrum of the 130- enriched crystals. Residual backgrounds in the subtracted spectrum were fit using spectra generated by Monte-Carlo simulations of natural radioactive contaminants located in and on the crystals. The 2{nu}{beta}{beta} half-life was measured to be T{sup 2{nu}}{sub 1/2} = [9.81{+-} #6;0.96(stat){+-} 0.49(syst)]#2;x10{sup 20} y.

  18. Superior thermoelectric performance in PbTe-PbS pseudo-binary. Extremely low thermal conductivity and modulated carrier concentration

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

    Wu, D.; Zhao, L. -D.; Tong, X.; Li, W.; Wu, L.; Tan, Q.; Pei, Y.; Huang, L.; Li, J. -F.; Zhu, Y.; et al

    2015-05-19

    Lead chalcogenides have exhibited their irreplaceable role as thermoelectric materials at the medium temperature range, owing to highly degenerate electronic bands and intrinsically low thermal conductivities. PbTe-PbS pseudo-binary has been paid extensive attentions due to the even lower thermal conductivity which originates largely from the coexistence of both alloying and phase-separated precipitations. To investigate the competition between alloying and phase separation and its pronounced effect on the thermoelectric performance in PbTe-PbS, we systematically studied Spark Plasma Sintered (SPSed), 3 at% Na- doped (PbTe)1-x(PbS)x samples with x=10%, 15%, 20%, 25%, 30% and 35% by means of transmission electron microscopy (TEM) observationsmore » and theoretical calculations. Corresponding to the lowest lattice thermal conductivity as a result of the balance between point defect- and precipitates- scattering, the highest figure of merit ZT~2.3 was obtained at 923 K when PbS phase fraction x is at 20%. The consistently lower lattice thermal conductivities in SPSed samples compared with corresponding ingots, resulting from the powdering and follow-up consolidation processes, also contribute to the observed superior ZT. Notably, the onset of carrier concentration modulation ~600 K due to excessive Na’s diffusion and re-dissolution leads to the observed saturations of electrical transport properties, which is believed equally crucial to the outstanding thermoelectric performance of SPSed PbTe-PbS samples.« less

  19. Strain induced Z{sub 2} topological insulating state of ?-As{sub 2}Te{sub 3}

    SciTech Connect (OSTI)

    Pal, Koushik; Waghmare, Umesh V.

    2014-08-11

    Topological insulators are non-trivial quantum states of matter which exhibit a gap in the electronic structure of their bulk form, but a gapless metallic electronic spectrum at the surface. Here, we predict a uniaxial strain induced electronic topological transition (ETT) from a band to topological insulating state in the rhombohedral phase (space group: R3{sup }m) of As{sub 2}Te{sub 3} (?-As{sub 2}Te{sub 3}) through first-principles calculations including spin-orbit coupling within density functional theory. The ETT in ?-As{sub 2}Te{sub 3} is shown to occur at the uniaxial strain ?{sub zz}?=??0.05 (?{sub zz}?=?1.77?GPa), passing through a Weyl metallic state with a single Dirac cone in its electronic structure at the ? point. We demonstrate the ETT through band inversion and reversal of parity of the top of the valence and bottom of the conduction bands leading to change in the ?{sub 2} topological invariant ?{sub 0} from 0 to 1 across the transition. Based on its electronic structure and phonon dispersion, we propose ultra-thin films of As{sub 2}Te{sub 3} to be promising for use in ultra-thin stress sensors, charge pumps, and thermoelectrics.

  20. Fully gapped superconductivity in In-doped topological crystalline insulator Pb0.5Sn0.5Te

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

    Du, Guan; Gu, G. D.; Du, Zengyi; Fang, Delong; Yang, Huan; Zhong, R. D.; Schneeloch, J.; Wen, Hai -Hu

    2015-07-27

    In this study, superconductors derived from topological insulators and topological crystalline insulators by chemical doping have long been considered to be candidates as topological superconductors. Pb0.5Sn0.5Te is a topological crystalline insulator with mirror symmetry protected surface states on (001)-, (011)-, and (111)-oriented surfaces. The superconductor (Pb0.5Sn0.5)0.7In0.3Te is produced by In doping in Pb0.5Sn0.5Te, and is thought to be a topological superconductor. Here we report scanning tunneling spectroscopy measurements of the superconducting state as well as the superconducting energy gap in (Pb0.5Sn0.5)0.7In0.3Te on a (001)-oriented surface. The spectrum can be well fitted by an anisotropic s-wave gap function of Δ =more » 0.72 + 0.18cos4θ meV using Dynes model. The results show that the superconductor seems to be a fully gapped one without any in-gap states, in contradiction with the expectation of a topological superconductor.« less

  1. Superior thermoelectric performance in PbTe-PbS pseudo-binary. Extremely low thermal conductivity and modulated carrier concentration

    SciTech Connect (OSTI)

    Wu, D.; Zhao, L. -D.; Tong, X.; Li, W.; Wu, L.; Tan, Q.; Pei, Y.; Huang, L.; Li, J. -F.; Zhu, Y.; Kanatzidis, M. G.; He, J.

    2015-05-19

    Lead chalcogenides have exhibited their irreplaceable role as thermoelectric materials at the medium temperature range, owing to highly degenerate electronic bands and intrinsically low thermal conductivities. PbTe-PbS pseudo-binary has been paid extensive attentions due to the even lower thermal conductivity which originates largely from the coexistence of both alloying and phase-separated precipitations. To investigate the competition between alloying and phase separation and its pronounced effect on the thermoelectric performance in PbTe-PbS, we systematically studied Spark Plasma Sintered (SPSed), 3 at% Na- doped (PbTe)1-x(PbS)x samples with x=10%, 15%, 20%, 25%, 30% and 35% by means of transmission electron microscopy (TEM) observations and theoretical calculations. Corresponding to the lowest lattice thermal conductivity as a result of the balance between point defect- and precipitates- scattering, the highest figure of merit ZT~2.3 was obtained at 923 K when PbS phase fraction x is at 20%. The consistently lower lattice thermal conductivities in SPSed samples compared with corresponding ingots, resulting from the powdering and follow-up consolidation processes, also contribute to the observed superior ZT. Notably, the onset of carrier concentration modulation ~600 K due to excessive Nas diffusion and re-dissolution leads to the observed saturations of electrical transport properties, which is believed equally crucial to the outstanding thermoelectric performance of SPSed PbTe-PbS samples.

  2. Thermal conductivity of Bi{sub 2}Te{sub 3} tilted nanowires, a molecular dynamics study

    SciTech Connect (OSTI)

    Li, Shen Lacroix, David; Termentzidis, Konstantinos; Chaput, Laurent; Stein, Nicolas; Frantz, Cedric

    2015-06-08

    Evidence for an excellent compromise between structural stability and low thermal conductivity has been achieved with tilted Bi{sub 2}Te{sub 3} nanowires. The latter ones were recently fabricated and there is a need in modeling and characterization. The structural stability and the thermal conductivity of Bi{sub 2}Te{sub 3} nanowires along the tilted [015]* direction and along the [010] direction have been explored. For the two configurations of nanowires, the effect of the length and the cross section on the thermal conductivity is discussed. The thermal conductivity of infinite size tilted nanowire is 0.34?W/m K, significantly reduced compared to nanowire along the [010] direction (0.59?W/m K). This reveals that in Bi{sub 2}Te{sub 3} nanowires the structural anisotropy can be as important as size effects to reduce the thermal conductivity. The main reason is the reduction of the phonon mean free path which is found to be 1.7?nm in the tilted nanowires, compared to 5.3?nm for the nanowires along the [010] direction. The fact that tilted Bi{sub 2}Te{sub 3} nanowire is mechanically stable and it has extremely low thermal conductivity suggests these nanowires as a promising material for future thermoelectric generation application.

  3. Effects of chemo-mechanical polishing on CdZnTe X-ray and gamma-ray detectors

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

    Egarievwe, Stephen E.; Hossain, Anwar; Okwechime, Ifechukwude O.; Gul, Rubi; James, Ralph B.

    2015-06-23

    Here, mechanically polishing cadmium zinc telluride (CdZnTe) wafers for x-ray and gamma-ray detectors often is inadequate in removing surface defects caused by cutting them from the ingots. Fabrication-induced defects, such as surface roughness, dangling bonds, and nonstoichiometric surfaces, often are reduced through polishing and etching the surface. In our earlier studies of mechanical polishing with alumina powder, etching with hydrogen bromide in hydrogen peroxide solution, and chemomechanical polishing with bromine–methanol–ethylene glycol solution, we found that the chemomechanical polishing process produced the least surface leakage current. In this research, we focused on using two chemicals to chemomechanically polish CdZnTe wafers aftermore » mechanical polishing, viz. bromine–methanol–ethylene glycol (BME) solution, and hydrogen bromide (HBr) in a hydrogen peroxide and ethylene–glycol solution. We used x-ray photoelectron spectroscopy (XPS), current–voltage (I–V) measurements, and Am-241 spectral response measurements to characterize and compare the effects of each solution. The results show that the HBr-based solution produced lower leakage current than the BME solution. Results from using the same chemomechanical polishing solution on two samples confirmed that the surface treatment affects the measured bulk current (a combination of bulk and surface currents). XPS results indicate that the tellurium oxide to tellurium peak ratios for the mechanical polishing process were reduced significantly by chemomechanical polishing using the BME solution (78.9% for Te 3d5/2O2 and 76.7% for Te 3d3/2O2) compared with the HBr-based solution (27.6% for Te 3d5/2O2 and 35.8% for Te 3d3/2O2). Spectral response measurements showed that the 59.5-keV peak of Am-241 remained under the same channel number for all three CdZnTe samples. While the BME-based solution gave a better performance of 7.15% full-width at half-maximum (FWHM) compared with 7.59% FWHM for the HBr-based solution, the latter showed a smaller variation in performance of 0.39% FWHM over 7 days compared with 0.69% for the BME-based solution.« less

  4. EVIDENCE OF A HADRONIC ORIGIN FOR THE TeV SOURCE J1834-087

    SciTech Connect (OSTI)

    Frail, D. A.; Claussen, M. J.; Mehault, J.

    2013-08-20

    We report on the discovery of compact, narrow OH line emission from the hydroxyl molecule at 1720 MHz toward the extended TeV source J1834-087. The origin of this high energy emission is unknown; it could be powered by one or more candidate neutron stars (leptonic) or by cosmic rays interacting with dense gas (hadronic). The OH emission is detected near the center of J1834-087, coincident with the radio continuum of the supernova remnant W41, and the radial velocity of the line is the same velocity as a giant molecular cloud along the line of sight. We argue that the OH is maser emission stimulated by the interaction of the W41 shock with the molecular cloud. The known correlation between {gamma}-ray bright supernova remnants and OH masers favors a hadronic interpretation for this high energy emission.

  5. Evidence for charge Kondo effect in superconducting Tl-doped PbTe

    SciTech Connect (OSTI)

    Fisher, I

    2010-01-11

    We report results of low-temperature thermodynamic and transport measurements of Pb{sub 1-x}Tl{sub x}Te single crystals for Tl concentrations up to the solubility limit of approximately x = 1.5%. For all doped samples, we observe a low-temperature resistivity upturn that scales in magnitude with the Tl concentration. The temperature and field dependence of this upturn are consistent with a charge Kondo effect involving degenerate Tl valence states differing by two electrons, with a characteristic Kondo temperature T{sub K} {approx} 6 K. The observation of such an effect supports an electronic pairing mechanism for superconductivity in this material and may account for the anomalously high T{sub c} values.

  6. Surface defect states in MBE-grown CdTe layers

    SciTech Connect (OSTI)

    Olender, Karolina; Wosinski, Tadeusz; Fronc, Krzysztof; Tkaczyk, Zbigniew; Chusnutdinow, Sergij; Karczewski, Grzegorz

    2014-02-21

    Semiconductor surface plays an important role in the technology of semiconductor devices. In the present work we report results of our deep-level transient spectroscopy (DLTS) investigations of surface defect states in nitrogen doped p-type CdTe layers grown by the molecular-beam epitaxy technique. We observed a deep-level trap associated with surface states, with the activation energy for hole emission of 0.33 eV. DLTS peak position in the spectra for this trap, and its ionization energy, strongly depend on the electric field. Our measurements allow to determine a mechanism responsible for the enhancement of hole emission rate from the traps as the phonon-assisted tunnel effect. Density of surface defect states significantly decreased as a result of passivation in ammonium sulfide. Capacitance-voltage measurements confirmed the results obtained by the DLTS technique.

  7. Testing the Technicolor Interpretation of the CDF Dijet Excess at the 8-TeV LHC

    SciTech Connect (OSTI)

    Eichten, Estia; Lane, Kenneth; Martin, Adam; Pilon, Eric

    2012-10-01

    Under the assumption that the dijet excess seen by the CDF Collaboration near 150 Gev in Wjj production is due to the lightest technipion of the low-scale technicolor process $\\rho_T \\rightarrow W \\pi_T$, we study its observability in LHC detectors for 8 TeV collisions and 20 inverse femtobarns of integrated luminosity. We describe interesting new kinematic tests that can provide independent confirmation of this LSTC hypothesis. We show that cuts similar to those employed by CDF, and recently by ATLAS, cannot confirm the dijet signal. We propose cuts tailored to the LSTC hypothesis and its backgrounds at the LHC that may reveal $\\rho_T \\rightarrow \\ell\

  8. Search for disappearing tracks in proton-proton collisions at ?s = 8 TeV

    SciTech Connect (OSTI)

    Khachatryan, V.

    2015-01-19

    A search is presented for long-lived charged particles that decay within the CMS detector and produce the signature of a disappearing track. Disappearing tracks are identified as those with little or no associated calorimeter energy deposits and with missing hits in the outer layers of the tracker. The search uses proton-proton collision data recorded at ?s = 8 TeV that corresponds to an integrated luminosity of 19.5 fb-1. The results of the search are interpreted in the context of the anomaly-mediated supersymmetry breaking (AMSB) model. The number of observed events is in agreement with the background expectation, and limits are set on the cross section of direct electroweak chargino production in terms of the chargino mass and mean proper lifetime. At 95% confidence level, AMSB models with a chargino mass less than 260 GeV, corresponding to a mean proper lifetime of 0.2 ns, are excluded.

  9. Direct Observation of Room-Temperature Polar Ordering in Colloidal GeTe Nanocrystals

    SciTech Connect (OSTI)

    Polking, Mark J.; Zheng, Haimei; Urban, Jeffrey J.; Milliron, Delia J.; Chan, Emory; Caldwell, Marissa A.; Raoux, Simone; Kisielowski, Christian F.; Ager III, Joel W.; Ramesh, Ramamoorthy; Alivisatos, A.P.

    2009-12-07

    Ferroelectrics and other materials that exhibit spontaneous polar ordering have demonstrated immense promise for applications ranging from non-volatile memories to microelectromechanical systems. However, experimental evidence of polar ordering and effective synthetic strategies for accessing these materials are lacking for low-dimensional nanomaterials. Here, we demonstrate the synthesis of size-controlled nanocrystals of the polar material germanium telluride (GeTe) using colloidal chemistry and provide the first direct evidence of room-temperature polar ordering in nanocrystals less than 5 nm in size using aberration-corrected transmission electron microscopy. Synchrotron x-ray diffraction and Raman studies demonstrate a sizeable polar distortion and a reversible size-dependent polar phase transition in these nanocrystals. The stability of polar ordering in solution-processible nanomaterials suggests an economical avenue to Tbit/in2-density non-volatile memory devices and other applications.

  10. Search for disappearing tracks in proton-proton collisions at ?s = 8 TeV

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

    Khachatryan, V.

    2015-01-19

    A search is presented for long-lived charged particles that decay within the CMS detector and produce the signature of a disappearing track. Disappearing tracks are identified as those with little or no associated calorimeter energy deposits and with missing hits in the outer layers of the tracker. The search uses proton-proton collision data recorded at ?s = 8 TeV that corresponds to an integrated luminosity of 19.5 fb-1. The results of the search are interpreted in the context of the anomaly-mediated supersymmetry breaking (AMSB) model. The number of observed events is in agreement with the background expectation, and limits aremoreset on the cross section of direct electroweak chargino production in terms of the chargino mass and mean proper lifetime. At 95% confidence level, AMSB models with a chargino mass less than 260 GeV, corresponding to a mean proper lifetime of 0.2 ns, are excluded.less

  11. Probing color coherence effects in pp collisions at √s = 7 TeV

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

    Chatrchyan, Serguei

    2014-06-11

    A study of color coherence effects in pp collisions at a center-of-mass energy of 7 TeV is presented. The data used in the analysis were collected in 2010 with the CMS detector at the LHC and correspond to an integrated luminosity of 36 inverse picobarns. Events are selected that contain at least three jets and where the two jets with the largest transverse momentum exhibit a back-to-back topology. The measured angular correlation between the second- and third-leading jet is shown to be sensitive to color coherence effects, and is compared to the predictions of Monte Carlo models with various implementationsmore » of color coherence. None of the models describe the data satisfactorily.« less

  12. Ultrafast terahertz-induced response of GeSbTe phase-change materials

    SciTech Connect (OSTI)

    Shu, Michael J.; Zalden, Peter; Chen, Frank; Weems, Ben; Chatzakis, Ioannis; Xiong, Feng; Jeyasingh, Rakesh; Pop, Eric; Philip Wong, H.-S.; Hoffmann, Matthias C.; Wuttig, Matthias; Lindenberg, Aaron M.

    2014-06-23

    The time-resolved ultrafast electric field-driven response of crystalline and amorphous GeSbTe films has been measured all-optically, pumping with single-cycle terahertz pulses as a means of biasing phase-change materials on a sub-picosecond time-scale. Utilizing the near-band-gap transmission as a probe of the electronic and structural response below the switching threshold, we observe a field-induced heating of the carrier system and resolve the picosecond-time-scale energy relaxation processes and their dependence on the sample annealing condition in the crystalline phase. In the amorphous phase, an instantaneous electroabsorption response is observed, quadratic in the terahertz field, followed by field-driven lattice heating, with Ohmic behavior up to 200?kV/cm.

  13. Search for resonant tt production in proton-proton collisions at ?s = 8 TeV

    SciTech Connect (OSTI)

    Khachatryan, Vardan

    2015-06-10

    A search is performed for the production of heavy resonances decaying into top-antitop quark pairs in proton-proton collisions at ?s = 8 TeV. Data used for the analyses were collected with the CMS detector and correspond to an integrated luminosity of 19.7 fb1. The search is performed using events with three different final states, defined by the number of leptons (electrons and muons) from the tt ? WbWb decay. The analyses are optimized for reconstruction of top quarks with high Lorentz boosts, where jet substructure techniques are used to enhance the sensitivity. Results are presented for all channels and a combination is performed. Furthermore, no significant excess of events relative to the expected yield from standard model processes is observed.

  14. Probing color coherence effects in pp collisions at $\\sqrt{s}=7\\,\\text {TeV} $

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

    Chatrchyan, Serguei; et al.

    2013-11-22

    A study of color coherence effects in pp collisions at a center-of-mass energy of 7 TeV is presented. The data used in the analysis were collected in 2010 with the CMS detector at the LHC and correspond to an integrated luminosity of 36 inverse picobarns. Events are selected that contain at least three jets and where the two jets with the largest transverse momentum exhibit a back-to-back topology. The measured angular correlation between the second- and third-leading jet is shown to be sensitive to color coherence effects, and is compared to the predictions of Monte Carlo models with various implementationsmoreof color coherence. None of the models describe the data satisfactorily.less

  15. Search for Single Vectorlike Quarks 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.; Alves, G. A.; Ancu, L. S.; Aoki, M.; Arnoud, Y.; Arov, M.; Askew, A.; sman, B.; Atramentov, O.; Avila, C.; BackusMayes, J.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Beale, S.; Bean, A.; Begalli, M.; Begel, M.; Belanger-Champagne, C.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besanon, M.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Bolton, T. A.; 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.; Burnett, T. H.; Buszello, C. P.; Calpas, B.; Camacho-Prez, E.; Carrasco-Lizarraga, M. A.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chen, G.; Chevalier-Thry, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Christoudias, T.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Croc, A.; Cutts, D.; ?wiok, M.; Das, A.; Davies, G.; De, K.; de Jong, S. J.; De La Cruz-Burelo, E.; Dliot, F.; Demarteau, M.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Dominguez, A.; Dorland, T.; 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.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Gadfort, T.; Garcia-Bellido, A.; Gavrilov, V.; Gay, P.; Geist, W.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Grannis, P. D.; Greder, S.; Greenlee, H.; Greenwood, Z. D.; Gregores, E. M.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grnendahl, S.; Grnewald, M. W.; Guo, F.; 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.; Hossain, S.; Hubacek, Z.; Huske, N.; Hynek, V.; Iashvili, I.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffr, M.; Jain, S.; Jamin, D.; Jesik, R.; Johns, K.; Johnson, M.; Johnston, D.; Jonckheere, A.; Jonsson, P.; Joshi, J.; 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.; Khatidze, D.; Kirby, M. H.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Kvita, J.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lellouch, J.; Li, L.; Li, Q. Z.; Lietti, S. M.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, Y.; Liu, Z.; Lobodenko, A.; Lokajicek, M.; Love, P.; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Mackin, D.; 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.; Mondal, N. K.; Muanza, G. S.; Mulhearn, M.; Nagy, E.; Naimuddin, M.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Novaes, S. F.; Nunnemann, T.; Obrant, G.; Orduna, J.; Osman, N.; Osta, J.; Otero y Garzn, G. J.; Owen, M.; Padilla, M.; Pangilinan, M.; Parashar, N.; Parihar, V.; Park, S. K.; Parsons, J.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, K.; Peters, Y.; Petrillo, G.; Ptroff, P.; Piegaia, R.; Piper, J.; Pleier, M.-A.; Podesta-Lerma, P. L. M.; Podstavkov, V. M.; Pol, M.-E.; Polozov, P.; Popov, A. V.; Prewitt, M.; Price, D.; Protopopescu, S.; Qian, J.; Quadt, A.; Quinn, B.; Rangel, M. S.; Ranjan, K.; Ratoff, P. N.; Razumov, I.; Renkel, P.; Rich, P.; Rijssenbeek, M.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Royon, C.; Rubinov, P.; Ruchti, R.; Safronov, G.; Sajot, G.; Snchez-Hernndez, A.; Sanders, M. P.; Sanghi, B.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schliephake, T.; Schlobohm, S.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shchukin, A. A.; Shivpuri, R. K.; Simak, V.; Sirotenko, V.; Skubic, P.; Slattery, P.; Smirnov, D.

    2011-02-22

    We present a search for hypothetical vectorlike quarks in pp? collisions at ?s=1.96 TeV. The data were collected by the D0 detector at the Fermilab Tevatron Collider and correspond to an integrated luminosity of 5.4 fb?. We select events with a final state composed of a W or Z boson and a jet consistent with a heavy object decay. We observe no significant excess in comparison to the background prediction and set limits on production cross sections for vectorlike quarks decaying to W+jet and Z+jet. These are the most stringent limits to date for electroweak single vectorlike quark production at hadron colliders.

  16. Higgs self-coupling measurements at a 100 TeV hadron collider

    SciTech Connect (OSTI)

    Barr, Alan J.; Dolan, Matthew J.; Englert, Christoph; Ferreira de Lima, Enoque Danilo; Spannowsky, Michael

    2015-02-03

    An important physics goal of a possible next-generation high-energy hadron collider will be precision characterisation of the Higgs sector and electroweak symmetry breaking. A crucial part of understanding the nature of electroweak symmetry breaking is measuring the Higgs self-interactions. We study dihiggs production in proton-proton collisions at 100 TeV centre of mass energy in order to estimate the sensitivity such a machine would have to variations in the trilinear Higgs coupling around the Standard Model expectation. We focus on the bb¯γγ final state, including possible enhancements in sensitivity by exploiting dihiggs recoils against a hard jet. In conclusion, we find that it should be possible to measure the trilinear self-coupling with 40% accuracy given 3/ab and 12% with 30/ab of data.

  17. Natural nanostructure and superlattice nanodomains in AgSbTe{sub 2}

    SciTech Connect (OSTI)

    Carlton, Christopher E.; De Armas, Ricardo; Shao-Horn, Yang E-mail: shaohorn@mit.edu; Ma, Jie; May, Andrew F.; Delaire, Olivier E-mail: shaohorn@mit.edu

    2014-04-14

    AgSbTe{sub 2} has long been of interest for thermoelectric applications because of its favorable electronic properties and its low lattice thermal conductivity of ?0.7?W/mK. In this work, we report new findings from a high-resolution transmission electron microscopy study revealing two nanostructures in single crystal Ag{sub 1?x}Sb{sub 1+x}Sb{sub 2+x} (with x?=?0, 0.1, 0.2); (i) a rippled natural nanostructure with a period of ?2.55?nm and (ii) superlattice ordered nanodomains consistent with cation ordering predicted in previous density functional theory studies. These nanostructures, combined with point-defects, probably serve as sources of scattering for phonons, thereby yielding a low lattice thermal conductivity over a wide temperature range.

  18. Performance Stabilization of CdTe PV Modules using Bias and Light

    SciTech Connect (OSTI)

    Silverman, T. J.; Deceglie, M. G.; Marion, B.; Kurtz, S. R.

    2014-07-01

    Reversible performance changes due to light exposure frustrate repeatable performance measurements on CdTe PV modules. It is common to use extended light-exposure to ensure that measurements are representative of outdoor performance. We quantify the extent to which such a light-exposed state depends on module temperature and consider bias in the dark to aid in stabilization. We evaluate the use of dark forward bias to bring about a performance state equivalent to that obtained with light exposure, and to maintain a light-exposed state prior to STC performance measurement. Our results indicate that the most promising method for measuring a light-exposed state is to use light exposure at controlled temperature followed by prompt STC measurement with a repeatable time interval between exposure and the STC measurement.

  19. Optical spectroscopy study of the three-dimensional Dirac semimetal ZrTe5

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

    Chen, R. Y.; Gu, G. D.; Zhang, S. J.; Schneeloch, J. A.; Zhang, C.; Li, Q.; Wang, N. L.

    2015-08-05

    Three-dimensional (3D) topological Dirac materials have been under intensive study recently. The layered compound ZrTe5 has been suggested to be one such material as a result of transport and angle-resolved photoemission spectroscopy experiments. Here, we perform infrared reflectivity measurements to investigate the underlying physics of this material. The derived optical conductivity increases linearly with frequency below normal interband transitions, which provides optical spectroscopic proof of a 3D Dirac semimetal. In addition, the plasma edge shifts dramatically to lower energy upon temperature cooling, which might be due to the shrinking of the lattice parameters. Additionally, an extremely sharp peak shows upmore » in the frequency-dependent optical conductivity, indicating the presence of a Van Hove singularity in the joint density of state.« less

  20. Hiding a Heavy Higgs Boson at the 7 TeV LHC

    SciTech Connect (OSTI)

    Bai, Yang; Fan, JiJi; Hewett, JoAnne L.

    2012-03-20

    A heavy Standard Model Higgs boson is not only disfavored by electroweak precision observables but is also excluded by direct searches at the 7 TeV LHC for a wide range of masses. Here, we examine scenarios where a heavy Higgs boson can be made consistent with both the indirect constraints and the direct null searches by adding only one new particle beyond the Standard Model. This new particle should be a weak multiplet in order to have additional contributions to the oblique parameters. If it is a color singlet, we find that a heavy Higgs with an intermediate mass of 200-300 GeV can decay into the new states, suppressing the branching ratios for the standard model modes, and thus hiding a heavy Higgs at the LHC. If the new particle is also charged under QCD, the Higgs production cross section from gluon fusion can be reduced significantly due to the new colored particle one-loop contribution. Current collider constraints on the new particles allow for viable parameter space to exist in order to hide a heavy Higgs boson. We categorize the general signatures of these new particles, identify favored regions of their parameter space and point out that discovering or excluding them at the LHC can provide important indirect information for a heavy Higgs. Finally, for a very heavy Higgs boson, beyond the search limit at the 7 TeV LHC, we discuss three additional scenarios where models would be consistent with electroweak precision tests: including an additional vector-like fermion mixing with the top quark, adding another U(1) gauge boson and modifying triple-gauge boson couplings.

  1. Investigating Broadband Variability of the TeV Blazar 1ES 1959+650

    SciTech Connect (OSTI)

    Aliu, E.; Archambault, S.; Arlen, T.; Aune, T.; Barnacka, A.; Beilicke, M.; Benbow, W.; Berger, K.; Bird, R.; Bouvier, A.; Buckley, J. H.; Bugaev, V.; Cerruti, M.; Chen, X.; Ciupik, L.; Collins-Hughes, E.; Connolly, M. P.; Cui, W.; Dumm, J.; Eisch, J. D.; Falcone, A.; Federici, S.; Feng, Q.; Finley, J. P.; Fleischhack, H.; Hanna, D.; Holder, J.; Hughes, G.; Hughes, Z.; Humensky, T. B.; Johnson, C. A.; Kaaret, P.; Kar, P.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; Madhavan, A. S.; Majumdar, P.; McArthur, S.; McCann, A.; Meagher, K.; Millis, J.; Moriarty, P.; Mukherjee, R.; Nelson, T.; Nieto, D.; O'Faolain de Bhroithe, A.; Ong, R. A.; Otte, A. N.; Park, N.; Perkins, J. S.; Pohl, M.; Popkow, A.; Prokoph, H.; Quinn, J.; Ragan, K.; Rajotte, J.; Reyes, L. C.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Sadun, A.; Santander, M.; Sembroski, G. H.; Shahinyan, K.; Sheidaei, F.; Smith, A. W.; Staszak, D.; Telezhinsky, I.; Theiling, M.; Tyler, J.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Wakeley, S. P.; Weekes, T. C.; Weinstein, A.; Welsing, R.; Wilhelm, A.; Williams, D. A.; Zitzer, B.; Boettcher, M.; Fumagalli, M.

    2014-12-03

    We summarize broadband observations of the TeV-emitting blazar 1ES 1959 650, including optical R-band observations by the robotic telescopes Super-LOTIS and iTelescope, UV observations by Swift Ultraviolet and Optical Telescope, X-ray observations by the Swift X-ray Telescope, high-energy gamma-ray observations with the Fermi Large Area Telescope, and very-high-energy (VHE) gamma-ray observations by VERITAS above 315 GeV, all taken between 2012 April 17 and 2012 June 1 (MJD 56034 and 56079). The contemporaneous variability of the broadband spectral energy distribution is explored in the context of a simple synchrotron self Compton (SSC) model. In the SSC emission scenario, we find that the parameters required to represent the high state are significantly different than those in the low state. Motivated by possible evidence of gas in the vicinity of the blazar, we also investigate a reflected emission model to describe the observed variability pattern. This model assumes that the non-thermal emission from the jet is reflected by a nearby cloud of gas, allowing the reflected emission to re-enter the blob and produce an elevated gamma-ray state with no simultaneous elevated synchrotron flux. The model applied here, although not required to explain the observed variability pattern, represents one possible scenario which can describe the observations. As applied to an elevated VHE state of 66% of the Crab Nebula flux, observed on a single night during the observation period, the reflected emission scenario does not support a purely leptonic non-thermal emission mechanism. The reflected model does, however, predict a reflected photon field with sufficient energy to enable elevated gamma-ray emission via pion production with protons of energies between 10 and 100 TeV.

  2. Investigating broadband variability of the TeV blazar 1ES 1959+650

    SciTech Connect (OSTI)

    Aliu, E.; Archambault, S.; Arlen, T.; Aune, T.; Barnacka, A.; Beilicke, M.; Benbow, W.; Berger, K.; Bird, R.; Bouvier, A.; Buckley, J. H.; Bugaev, V.; Cerruti, M.; Chen, X.; Ciupik, L.; Collins-Hughes, E.; Connolly, M. P.; Cui, W.; Dumm, J.; Eisch, J. D.; Falcone, A.; Federici, S.; Feng, Q.; Finley, J. P.; Fleischhack, H.; Fortin, P.; Fortson, L.; Furniss, A.; Galante, N.; Gillanders, G. H.; Griffin, S.; Griffiths, S. T.; Grube, J.; Gyuk, G.; Håkansson, N.; Hanna, D.; Holder, J.; Hughes, G.; Hughes, Z.; Humensky, T. B.; Johnson, C. A.; Kaaret, P.; Kar, P.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krawczynski, H.; Krennrich, F.; Lang, M. J.; Madhavan, A. S.; Majumdar, P.; McArthur, S.; McCann, A.; Meagher, K.; Millis, J.; Moriarty, P.; Mukherjee, R.; Nelson, T.; Nieto, D.; de Bhróithe, A. O'Faoláin; Ong, R. A.; Otte, A. N.; Park, N.; Perkins, J. S.; Pohl, M.; Popkow, A.; Prokoph, H.; Quinn, J.; Ragan, K.; Rajotte, J.; Reyes, L. C.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Sadun, A.; Santander, M.; Sembroski, G. H.; Shahinyan, K.; Sheidaei, F.; Smith, A. W.; Staszak, D.; Telezhinsky, I.; Theiling, M.; Tyler, J.; Varlotta, A.; Vassiliev, V. V.; Vincent, S.; Wakely, S. P.; Weekes, T. C.; Weinstein, A.; Welsing, R.; Wilhelm, A.; Williams, D. A.; Zitzer, and B.; Böttcher, M.; Fumagalli, M.

    2014-12-03

    We summarize broadband observations of the TeV-emitting blazar 1ES 1959 650, including optical R-band observations by the robotic telescopes Super-LOTIS and iTelescope, UV observations by Swift UVOT, X-ray observations by the Swift X-ray Telescope, high-energy gamma-ray observations with the Fermi Large Area Telescope, and very-high-energy (VHE) gamma-ray observations by VERITAS above 315 GeV, all taken between 2012 April 17 and 2012 June 1 (MJD 56034 and 56079). The contemporaneous variability of the broadband spectral energy distribution is explored in the context of a simple synchrotron self Compton (SSC) model. In the SSC emission scenario, we find that the parameters required to represent the high state are significantly different than those in the low state. Motivated by possible evidence of gas in the vicinity of the blazar, we also investigate a reflected emission model to describe the observed variability pattern. This model assumes that the non-thermal emission from the jet is reflected by a nearby cloud of gas, allowing the reflected emission to re-enter the blob and produce an elevated gamma-ray state with no simultaneous elevated synchrotron flux. The model applied here, although not required to explain the observed variability pattern, represents one possible scenario which can describe the observations. As applied to an elevated VHE state of 66% of the Crab Nebula flux, observed on a single night during the observation period, the reflected emission scenario does not support a purely leptonic non-thermal emission mechanism. The reflected model does, however, predict a reflected photon field with sufficient energy to enable elevated gamma-ray emission via pion production with protons of energies between 10 and 100 TeV.

  3. Heliospheric influence on the anisotropy of TeV cosmic rays

    SciTech Connect (OSTI)

    Zhang, Ming; Zuo, Pingbing; Pogorelov, Nikolai

    2014-07-20

    This paper provides a theory of using Liouville's theorem to map the anisotropy of TeV cosmic rays seen at Earth using the particle distribution function in the local interstellar medium (LISM). The ultimate source of cosmic ray anisotropy is the energy, pitch angle, and spatial dependence of the cosmic ray distribution function in the LISM. Because young nearby cosmic ray sources can make a special contribution to the cosmic ray anisotropy, the anisotropy depends on the source age, distance and magnetic connection, and particle diffusion of these cosmic rays, all of which make the anisotropy sensitive to the particle energy. When mapped through the magnetic and electric field of a magnetohydrodynamic model heliosphere, the large-scale dipolar and bidirectional interstellar anisotropy patterns become distorted if they are seen from Earth, resulting in many small structures in the observations. Best fits to cosmic ray anisotropy measurements have allowed us to estimate the particle density gradient and pitch angle anisotropies in the LISM. It is found that the heliotail, hydrogen deflection plane, and the plane perpendicular to the LISM magnetic field play a special role in distorting cosmic ray anisotropy. These features can lead to an accurate determination of the LISM magnetic field direction and polarity. The effects of solar cycle variation, the Sun's coronal magnetic field, and turbulence in the LISM and heliospheric magnetic fields are minor but clearly visible at a level roughly equal to a fraction of the overall anisotropy amplitude. The heliospheric influence becomes stronger at lower energies. Below 1 TeV, the anisotropy is dominated by small-scale patterns produced by disturbances in the heliosphere.

  4. Investigating broadband variability of the TeV blazar 1ES 1959+650

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

    Aliu, E.; Archambault, S.; Arlen, T.; Aune, T.; Barnacka, A.; Beilicke, M.; Benbow, W.; Berger, K.; Bird, R.; Bouvier, A.; et al

    2014-12-03

    We summarize broadband observations of the TeV-emitting blazar 1ES 1959 650, including optical R-band observations by the robotic telescopes Super-LOTIS and iTelescope, UV observations by Swift UVOT, X-ray observations by the Swift X-ray Telescope, high-energy gamma-ray observations with the Fermi Large Area Telescope, and very-high-energy (VHE) gamma-ray observations by VERITAS above 315 GeV, all taken between 2012 April 17 and 2012 June 1 (MJD 56034 and 56079). The contemporaneous variability of the broadband spectral energy distribution is explored in the context of a simple synchrotron self Compton (SSC) model. In the SSC emission scenario, we find that the parameters requiredmore » to represent the high state are significantly different than those in the low state. Motivated by possible evidence of gas in the vicinity of the blazar, we also investigate a reflected emission model to describe the observed variability pattern. This model assumes that the non-thermal emission from the jet is reflected by a nearby cloud of gas, allowing the reflected emission to re-enter the blob and produce an elevated gamma-ray state with no simultaneous elevated synchrotron flux. The model applied here, although not required to explain the observed variability pattern, represents one possible scenario which can describe the observations. As applied to an elevated VHE state of 66% of the Crab Nebula flux, observed on a single night during the observation period, the reflected emission scenario does not support a purely leptonic non-thermal emission mechanism. The reflected model does, however, predict a reflected photon field with sufficient energy to enable elevated gamma-ray emission via pion production with protons of energies between 10 and 100 TeV.« less

  5. Quantifying electron-phonon coupling in CdTe{sub 1−x}Se{sub x} nanocrystals via coherent phonon manipulation

    SciTech Connect (OSTI)

    Spann, B. T.; Xu, X.

    2014-08-25

    We employ ultrafast transient absorption spectroscopy with temporal pulse shaping to manipulate coherent phonon excitation and quantify the strength of electron-phonon coupling in CdTe{sub 1−x}Se{sub x} nanocrystals (NCs). Raman active CdSe and CdTe longitudinal optical phonon (LO) modes are excited and probed in the time domain. By temporally controlling pump pulse pairs to coherently excite and cancel coherent phonons in the CdTe{sub 1−x}Se{sub x} NCs, we estimate the relative amount of optical energy that is coupled to the coherent CdSe LO mode.

  6. The effects of surface bond relaxation on electronic structure of Sb{sub 2}Te{sub 3} nano-films by first-principles calculation

    SciTech Connect (OSTI)

    Li, C. Zhao, Y. F.; Fu, C. X.; Gong, Y. Y.; Chi, B. Q.; Sun, C. Q.

    2014-10-15

    The effects of vertical compressive stress on Sb{sub 2}Te{sub 3} nano-films have been investigated by the first principles calculation, including stability, electronic structure, crystal structure, and bond order. It is found that the band gap of nano-film is sensitive to the stress in Sb{sub 2}Te{sub 3} nano-film and the critical thickness increases under compressive stress. The band gap and band order of Sb{sub 2}Te{sub 3} film has been affected collectively by the surface and internal crystal structures, the contraction ratio between surface bond length of nano-film and the corresponding bond length of bulk decides the band order of Sb{sub 2}Te{sub 3} film.

  7. Temperature-sensitive junction transformations for mid-wavelength HgCdTe photovoltaic infrared detector arrays by laser beam induced current microscope

    SciTech Connect (OSTI)

    Qiu, Weicheng; Hu, Weida Lin, Tie; Yin, Fei; Zhang, Bo; Chen, Xiaoshuang; Lu, Wei; Cheng, Xiang'ai Wang, Rui

    2014-11-10

    In this paper, we report on the disappearance of the photosensitive area extension effect and the unusual temperature dependence of junction transformation for mid-wavelength, n-on-p HgCdTe photovoltaic infrared detector arrays. The n-type region is formed by B{sup +} ion implantation on Hg-vacancy-doped p-type HgCdTe. Junction transformations under different temperatures are visually captured by a laser beam induced current microscope. A physical model of temperature dependence on junction transformation is proposed and demonstrated by using numerical simulations. It is shown that Hg-interstitial diffusion and temperature activated defects jointly lead to the p-n junction transformation dependence on temperature, and the weaker mixed conduction compared with long-wavelength HgCdTe photodiode contributes to the disappearance of the photosensitive area extension effect in mid-wavelength HgCdTe infrared detector arrays.

  8. Comparison of crystal growth and thermoelectric properties of n-type Bi-Se-Te and p-type Bi-Sb-Te nanocrystalline thin films: Effects of homogeneous irradiation with an electron beam

    SciTech Connect (OSTI)

    Takashiri, Masayuki, E-mail: takashiri@tokai-u.jp; Imai, Kazuo; Uyama, Masato; Nishi, Yoshitake [Department of Materials Science, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Hagino, Harutoshi; Miyazaki, Koji [Department of Mechanical and Control Engineering, Kyushu Institute of Technology, 1-1 Sensui, Tobata-ku, Kitakyushu 804-8550 (Japan); Tanaka, Saburo [Department of Mechanical Engineering, College of Engineering, Nihon University, Nakagawara, Tokusada, Tamuramachi, Koriyama, Fukushima 963-8642 (Japan)

    2014-06-07

    The effects of homogenous electron beam (EB) irradiation on the crystal growth and thermoelectric properties of n-type Bi-Se-Te and p-type Bi-Sb-Te thin films were investigated. Both types of thin films were prepared by flash evaporation, after which homogeneous EB irradiation was performed at an acceleration voltage of 0.17?MeV. For the n-type thin films, nanodots with a diameter of less than 10?nm were observed on the surface of rice-like nanostructures, and crystallization and crystal orientation were improved by EB irradiation. The resulting enhancement of mobility led to increased electrical conductivity and thermoelectric power factor for the n-type thin films. In contrast, the crystallization and crystal orientation of the p-type thin films were not influenced by EB irradiation. The carrier concentration increased and mobility decreased with increased EB irradiation dose, possibly because of the generation of defects. As a result, the thermoelectric power factor of p-type thin films was not improved by EB irradiation. The different crystallization behavior of the n-type and p-type thin films is attributed to atomic rearrangement during EB irradiation. Selenium in the n-type thin films is more likely to undergo atomic rearrangement than the other atoms present, so only the crystallinity of the n-type Bi-Se-Te thin films was enhanced.

  9. Property Improvement in CZT via Modeling and Processing Innovations . Te-particles in vertical gradient freeze CZT: Size and Spatial Distributions and Constitutional Supercooling

    SciTech Connect (OSTI)

    Henager, Charles H.; Alvine, Kyle J.; Bliss, Mary; Riley, Brian J.; Stave, Jean A.

    2014-10-01

    A section of a vertical gradient freeze CZT boule approximately 2100-mm3 with a planar area of 300-mm2 was prepared and examined using transmitted IR microscopy at various magnifications to determine the three-dimensional spatial and size distributions of Te-particles over large longitudinal and radial length scales. The boule section was approximately 50-mm wide by 60-mm in length by 7-mm thick and was doubly polished for TIR work. Te-particles were imaged through the thickness using extended focal imaging to locate the particles in thickness planes spaced 15-m apart and then in plane of the image using xy-coordinates of the particle center of mass so that a true three dimensional particle map was assembled for a 1-mm by 45-mm longitudinal strip and for a 1-mm by 50-mm radial strip. Te-particle density distributions were determined as a function of longitudinal and radial positions in these strips, and treating the particles as vertices of a network created a 3D image of the particle spatial distribution. Te-particles exhibited a multi-modal log-normal size density distribution that indicated a slight preference for increasing size with longitudinal growth time, while showing a pronounced cellular network structure throughout the boule that can be correlated to dislocation network sizes in CZT. Higher magnification images revealed a typical Rayleigh-instability pearl string morphology with large and small satellite droplets. This study includes solidification experiments in small crucibles of 30:70 mixtures of Cd:Te to reduce the melting point below 1273 K (1000C). These solidification experiments were performed over a wide range of cooling rates and clearly demonstrated a growth instability with Te-particle capture that is suggested to be responsible for one of the peaks in the size distribution using size discrimination visualization. The results are discussed with regard to a manifold Te-particle genesis history as 1) Te-particle direct capture from melt-solid growth instabilities, 2) Te-particle formation from dislocation core diffusion and the formation and breakup of Te-tubes, and 3) Te-particle formation due to classical nucleation and growth as precipitates.

  10. Magneto-optical characterizations of FeTe???Se??? thin films with critical current density over 1 MA/cm

    SciTech Connect (OSTI)

    Sun, Yue; Li, Qiang; Tsuchiya, Yuji; Pyon, Sunseng; Tamegai, Tsuyoshi; Zhang, Cheng; Ozaki, Toshinori

    2015-01-01

    We performed magneto-optical (MO) measurements on FeTe???Se??? thin films grown on LaAlO? (LAO) and Yttria-stabilized zirconia (YSZ) single-crystalline substrates. These thin films show superconducting transition temperature Tc ~19 K, 4 K higher than the bulk sample. Typical roof-top patterns can be observed in the MO images of thin films grown on LAO and YSZ, from which a large and homogeneous critical current density Jc ~ 3 - 4 x 10? A/cm at 5 K was obtained. Magnetic flux penetration measurement reveals that the current is almost isotropically distributed in the two thin films. Compared with bulk crystals, FeTe???Se??? thin film demonstrates not only higher Tc, but also much larger Jc, which is attractive for applications.

  11. Deflection and Extraction of Pb Ions up to 33 TeV/c by a Bent Silicon Crystal

    SciTech Connect (OSTI)

    Arduini, G.; Biino, C.; Clement, M.; Cornelis, K.; Doble, N.; Elsener, K.; Ferioli, G.; Fidecaro, G.; Gatignon, L.; Grafstroem, P.; Gyr, M.; Herr, W.; Klem, J.; Mikkelsen, U.; Weisse, E.; Mo Uggerho Taratin, A.; Freund, A.; Keppler, P.; Major, J.

    1997-11-01

    The first results from an experiment to deflect a beam of fully stripped, ultrarelativistic Pb{sup 82+} ions of 400 GeV/c per unit of charge, equivalent to 33 TeV/c , by means of a bent crystal are reported. Deflection efficiencies are as high as 14{percent}, in agreement with theoretical estimates. In a second experiment a bent crystal was used to extract 270 GeV/c -per-charge Pb{sup 82+} (22 TeV/c) ions from a coasting beam in the CERN-SPS, and a high extraction efficiency of up to 10{percent} was found. These represent the first measurements to demonstrate applications of bent crystals in high energy heavy ion beams. {copyright} {ital 1997} {ital The American Physical Society}

  12. Blinking suppression of CdTe quantum dots on epitaxial graphene and the analysis with Marcus electron transfer

    SciTech Connect (OSTI)

    Hirose, Takuya; Tamai, Naoto, E-mail: tamai@kwansei.ac.jp [Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan); Kutsuma, Yasunori; Kurita, Atsusi; Kaneko, Tadaaki [Department of Physics, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan)

    2014-08-25

    We have prepared epitaxial graphene by a Si sublimation method from 4H-SiC. Single-particle spectroscopy of CdTe quantum dots (QDs) on epitaxial graphene covered with polyvinylpyrrolidone (PVP) or polyethylene glycol (PEG) showed the suppression of luminescence blinking and ?10 times decreased luminescence intensity as compared with those on a glass. The electronic coupling constant, H{sub 01}, between CdTe QDs and graphene was calculated to be (3.3??0.4)??10{sup 2?}cm{sup ?1} in PVP and (3.7??0.8)??10{sup 2?}cm{sup ?1} in PEG based on Marcus theory of electron transfer and Tang-Marcus model of blinking with statistical distribution.

  13. Search for high-mass diphoton resonances in pp collisions ats=8 TeVwith the ATLAS detector

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

    Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; et al

    2015-08-14

    This article describes a search for high-mass resonances decaying to a pair of photons using a sample of 20.3 fb-1 of pp collisions at s√=8 TeV recorded with the ATLAS detector at the Large Hadron Collider. The data are found to be in agreement with the Standard Model prediction, and limits are reported in the framework of the Randall-Sundrum model. This theory leads to the prediction of graviton states, the lightest of which could be observed at the Large Hadron Collider. A lower limit of 2.66 (1.41) TeV at 95% confidence level is set on the mass of the lightestmore » graviton for couplings of k/M¯¯Pl=0.1 (0.01).« less

  14. Search for Z? events with large missing transverse energy 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.

    2012-10-02

    We present the first search for new phenomena in Z? final states with large missing transverse energy using data corresponding to an integrated luminosity of 6.2 fb? collected with the D0 experiment in pp? collisions at ?s=1.96 TeV. This signature is predicted in gauge-mediated supersymmetry-breaking models, where the lightest neutralino ??? is the next-to-lightest supersymmetric particle and is produced in pairs, possibly through decay from heavier supersymmetric particles. The ??? can decay either to a Z boson or a photon and an associated gravitino that escapes detection. We exclude this model at the 95% C.L. for supersymmetry-breaking scales of ?<87 TeV.

  15. Les Houches Physics at TeV Colliders 2005 Beyond the Standard Model Working Group: Summary Report

    SciTech Connect (OSTI)

    Allanach, B.C.; Grojean, C.; Skands, P.; Accomando, E.; Azuelos, G.; Baer, H.; Balazs, C.; Belanger, G.; Benakli, K.; Boudjema, F.; Brelier, B.; Bunichev, V.; Cacciapaglia, G.; Carena, M.; Choudhury, D.; Delsart, P.-A.; De Sanctis, U.; Desch, K.; Dobrescu, B.A.; Dudko, L.; El Kacimi, M.; /Saclay, SPhT /CERN /Fermilab /INFN, Turin /Turin U. /Montreal U. /TRIUMF /Florida State U. /Argonne /Annecy, LAPTH /Paris, LPTHE /Moscow State U. /Cornell U., CIHEP /Delhi U. /Milan U. /INFN, Milan /Freiburg U. /Cadi Ayyad U., Marrakech /Orsay, LPT /Oslo U. /Lancaster U.

    2006-03-17

    The work contained herein constitutes a report of the ''Beyond the Standard Model'' working group for the Workshop ''Physics at TeV Colliders'', Les Houches, France, 2-20 May, 2005. We present reviews of current topics as well as original research carried out for the workshop. Supersymmetric and non-supersymmetric models are studied, as well as computational tools designed in order to facilitate their phenomenology.

  16. Synthesis, transport properties, and electronic structure of Cu{sub 2}CdSnTe{sub 4}

    SciTech Connect (OSTI)

    Dong, Yongkwan; Khabibullin, Artem R.; Wei, Kaya; Ge, Zhen-Hua; Woods, Lilia M. Nolas, George S.; Martin, Joshua; Salvador, James R.

    2014-06-23

    A new stannite phase was synthesized and its temperature dependent transport properties were investigated. Cu{sub 2}CdSnTe{sub 4} possesses strong p-type conduction, while the temperature dependence of the thermal conductivity exhibits typical dielectric behavior. Electronic structure calculations allowed for a description of the transport characteristics in terms the energy band structure, density of states, and Fermi surface. The potential for thermoelectric applications is also discussed.

  17. CdSe/ZnSe quantum dot structures grown by molecular beam epitaxy with a CdTe submonolayer stressor

    SciTech Connect (OSTI)

    Sedova, I. V. Lyublinskaya, O. G.; Sorokin, S. V.; Sitnikova, A. A.; Toropov, A. A.; Donatini, F.; Dang, Si Le; Ivanov, S. V.

    2007-11-15

    A procedure for formation of CdSe quantum dots (QDs) in a ZnSe matrix is suggested. The procedure is based on the introduction of a CdTe submonolayer stressor deposited on the matrix surface just before deposition of the material of the QDs. (For CdTe/ZnSe structure, the relative lattice mismatch is {delta}a/a {approx} 14%.) The stressor forms small strained islands at the ZnSe surface, thus producing local fields of high elastic stresses controlling the process of the self-assembling of the QDs. According to the data of transmission electron microscopy, this procedure allows a considerable increase in the surface density of QDs, with a certain decrease in their lateral dimensions (down to 4.5 {+-} 1.5 nm). In the photoluminescence spectra, a noticeable ({approx}150 meV) shift of the peak to longer wavelengths from the position of the reference CdSe/ZnSe QD structure is observed. The shift is due to some transformation of the morphology of the QDs and an increase in the Cd content in the QDs. Comprehensive studies of the nanostructures by recording and analyzing the excitation spectra of photoluminescence, the time-resolved photoluminescence spectra, and the cathodoluminescence spectra show that the emission spectra involve two types of optical transitions, namely, the type-I transitions in the CdSeTe/ZnSe QDs and the type-II transitions caused mainly by the low cadmium content (Zn,Cd)(Se,Te)/ZnSe layer formed between the QDs.

  18. Model independent search for new phenomena in pp? collisions at?s=1.96 TeV

    SciTech Connect (OSTI)

    Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D; Alkhazov, Georgiy D; Alton, Andrew K; Alverson, George O; Alves, Gilvan Augusto; Aoki, Masato

    2012-05-24

    We describe a model independent search for physics beyond the standard model in lepton final states. We examine 117 final states using 1.1 fb-1 of pp? collisions data at ?s = 1.96 TeV collected with the D0 detector. We conclude that all observed discrepancies between data and model can be attributed to uncertainties in the standard model background modeling, and hence we do not see any evidence for physics beyond the standard model.

  19. Study of asymmetries of Cd(Zn)Te devices investigated using photo-induced current transient spectroscopy, Rutherford backscattering, surface photo-voltage spectroscopy, and gamma ray spectroscopies

    SciTech Connect (OSTI)

    Crocco, J.; Bensalah, H.; Zheng, Q.; Dieguez, E.; Corregidor, V.; Avles, E.; Castaldini, A.; Fraboni, B.; Cavalcoli, D.; Cavallini, A.; Vela, O.

    2012-10-01

    Despite these recent advancements in preparing the surface of Cd(Zn)Te devices for detector applications, large asymmetries in the electronic properties of planar Cd(Zn)Te detectors are common. Furthermore, for the development of patterned electrode geometries, selection of each electrode surface is crucial for minimizing dark current in the device. This investigation presented here has been carried out with three objectives. Each objective is oriented towards establishing reliable methods for the selection of the anode and cathode surfaces independent of the crystallographic orientation. The objectives of this study are (i) investigate how the asymmetry in I-V characteristics of Cd(Zn)Te devices may be associated with the TeO2 interfacial layer using Rutherford backscattering to study the structure at the Au-Cd(Zn)Te interface, (ii) develop an understanding of how the concentration of the active traps in Cd(Zn)Te varies with the external bias, and (iii) propose non-destructive methods for selection of the anode and cathode which are independent of crystallographic orientation. The spectroscopic methods employed in this investigation include Rutherford backscattering spectroscopy, photo-induced current transient spectroscopy, and surface photo-voltage spectroscopy, as well as gamma ray spectroscopy to demonstrate the influence on detector properties.

  20. Functional glass slides for in vitro evaluation of interactions between osteosarcoma TE85 cells and mineral-binding ligands

    SciTech Connect (OSTI)

    Song, Jie; Chen, Julia; Klapperich, Catherine M.; Eng, Vincent; Bertozzi, Carolyn R.

    2004-07-20

    Primary amine-functionalized glass slides obtained through a multi-step plasma treatment were conjugated with anionic amino acids that are frequently found as mineral binding elements in acidic extracellular matrix components of natural bone. The modified glass surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and contact angle measurements. Human osteosarcoma TE85 cells were cultured on these functionalized slides and analyses on both protein and gene expression levels were performed to probe the ''biocompatibility'' of the surface ligands. Cell attachment and proliferation on anionic surfaces were either better than or comparable to those of cells cultured on tissue culture polystyrene (TCPS). The modified glass surfaces promoted the expression of osteocalcin, alkaline phosphatase activity and ECM proteins such as fibronectin and vitronectin under differentiation culture conditions. Transcript analysis using gene chip microarrays confirmed that culturing TE85 cells on anionic surfaces did not activate apoptotic pathways. Collectively, these results suggest that the potential mineral-binding anionic ligands examined here do not exert significant adverse effects on the expression of important osteogenic markers of TE85 cells. This work paves the way for the incorporation of these ligands into 3-dimensional artificial bone-like scaffolds.

  1. Electron interactions and Dirac fermions in graphene-Ge{sub 2}Sb{sub 2}Te{sub 5} superlattices

    SciTech Connect (OSTI)

    Sa, Baisheng; Sun, Zhimei

    2014-06-21

    Graphene based superlattices have been attracted worldwide interest due to the combined properties of the graphene Dirac cone feature and all kinds of advanced functional materials. In this work, we proposed a novel series of graphene-Ge{sub 2}Sb{sub 2}Te{sub 5} superlattices based on the density functional theory calculations. We demonstrated the stability in terms of energy and lattice dynamics for such kind of artificial materials. The analysis of the electronic structures unravels the gap opening nature at Dirac cone of the insert graphene layer. The Dirac fermions in the graphene layers are strongly affected by the electron spin orbital coupling in the Ge{sub 2}Sb{sub 2}Te{sub 5} layers. The present results show the possible application in phase-change data storage of such kind of superlattice materials, where the Ge{sub 2}Sb{sub 2}Te{sub 5} layers exhibit as the phase-change data storage media and the graphene layer works as the electrode, probe, and heat conductor.

  2. A CdTe position sensitive detector for a hard X- and gamma-ray wide field camera

    SciTech Connect (OSTI)

    Caroli, E.; Cesare, G. de; Donati, A.; Dusi, W.; Landini, G.; Stephen, J.B.; Perotti, F.

    1998-12-31

    An important region of the electromagnetic spectrum for astrophysics is the hard X- and gamma ray band between 10 keV and a few MeV, where several processes occur in a wide variety of objects and with different spatial distribution and time scales. In order to fulfill the observational requirements in this energy range and taking into account the opportunities given by small/medium size missions (e.g., on the ISS), the authors have proposed a compact, wide field camera based on a thick (1 cm) position sensitive CdTe detector (PSD). The detector is made of an array of 128x96 CdTe microspectrometers with a pixel size of 2x2 mm{sup 2}. The basic element of the PSD is the linear module that is an independent detection unit with 32 CdTe crystals and monolithic front-electronics (ASIC) supported by a thin (300 {micro}m) ceramic layer. The expected performance of the PSD over the operative energy range and some of the required ASIC functionality are presented and discussed.

  3. Magnetic structure and phase stability of the van der Waals bonded ferromagnet Fe3-xGeTe2

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

    May, Andrew F.; Calder, Stuart A.; Cantoni, Claudia; Cao, Huibo; McGuire, Michael A.

    2016-01-08

    The magnetic structure and phase diagram of the layered ferromagnetic compound Fe3GeTe2 have been investigated by a combination of synthesis, x-ray and neutron diffraction, high-resolution microscopy, and magnetization measurements. Single crystals were synthesized by self-flux reactions, and single-crystal neutron diffraction finds ferromagnetic order with moments of 1.11(5)μB/Fe aligned along the c axis at 4 K. These flux-grown crystals have a lower Curie temperature Tc ≈ 150 K than crystals previously grown by vapor transport (Tc = 220 K). The difference is a reduced Fe content in the flux-grown crystals, as illustrated by the behavior observed in a series of polycrystallinemore » samples. As Fe content decreases, so do the Curie temperature, magnetic anisotropy, and net magnetization. Furthermore, Hall-effect and thermoelectric measurements on flux-grown crystals suggest that multiple carrier types contribute to electrical transport in Fe3–xGeTe2 and structurally similar Ni3–xGeTe2.« less

  4. Search for Dilepton Resonances in pp Collisions at √s=7 TeV with the ATLAS Detector

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

    Aad, G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; Abramowicz, H.; Abreu, H.; et al

    2011-12-29

    This Letter reports on a search for narrow high-mass resonances decaying into dilepton final states. The data were recorded by the ATLAS experiment in pp collisions at √s=7 TeV at the Large Hadron Collider and correspond to a total integrated luminosity of 1.08 (1.21) fb⁻¹ in the e⁺e⁻ (μ⁺μ⁻) channel. No statistically significant excess above the standard model expectation is observed and upper limits are set at the 95% C.L. on the cross section times branching fraction of Z' resonances and Randall-Sundrum gravitons decaying into dileptons as a function of the resonance mass. A lower mass limit of 1.83 TeVmore » on the sequential standard model Z' boson is set. A Randall-Sundrum graviton with coupling k/M¯¯¯¯Pl=0.1 is excluded at 95% C.L. for masses below 1.63 TeV.« less

  5. Complete genome sequence of Veillonella parvula type strain (Te3T)

    SciTech Connect (OSTI)

    Gronow, Sabine; Welnitz, Sabine; Lapidus, Alla L.; Nolan, Matt; Ivanova, N; Glavina Del Rio, Tijana; Copeland, A; Chen, Feng; Tice, Hope; Pitluck, Sam; Cheng, Jan-Fang; Saunders, Elizabeth H; Brettin, Thomas S; Han, Cliff; Detter, J. Chris; Bruce, David; Goodwin, Lynne A.; Land, Miriam L; Hauser, Loren John; Chang, Yun-Juan; Jeffries, Cynthia; Pati, Amrita; Mavromatis, K; Mikhailova, Natalia; Chen, Amy; Palaniappan, Krishna; Chain, Patrick S. G.; Rohde, Manfred; Goker, Markus; Bristow, James; Eisen, Jonathan; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C; Klenk, Hans-Peter; Lucas, Susan

    2010-01-01

    Veillonella parvula (Veillon and Zuber 1898) Pr vot 1933 is the type species of the genus Veillonella in the family Veillonellaceae within the order Clostridiales. The species V. parvula is of interest because it is frequently isolated from dental plaque in the human oral cavity and can cause opportunistic infections. The species is strictly anaerobic and grows as small cocci which usually occur in pairs. Veillonellae are characterized by their unusual metabolism which is centered on the activity of the enzyme methylmalonyl-CoA decarboxylase. Strain Te3T, the type strain of the species, was isolated from the human intestinal tract. Here we describe the features of this organism, together with the complete genome sequence, and annotation. This is the first complete genome sequence of a member of the large clostridial family Veillonellaceae, and the 2,132,142 bp long single replicon genome with its 1859 protein-coding and 61 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.

  6. Estimation of the extragalactic background light using TeV observations of BL Lac objects

    SciTech Connect (OSTI)

    Sinha, Atreyee; Acharya, B. S.; Sahayanathan, S.; Godambe, S.; Misra, R. E-mail: acharya@tifr.res.in E-mail: gsagar@barc.ernet.in

    2014-11-01

    The very high-energy (VHE) gamma-ray spectral index of high-energy peaked blazars correlates strongly with its corresponding redshift, whereas no such correlation is observed in the X-ray or GeV bands. We attribute this correlation to photon-photon absorption of TeV photons with the extragalactic background light (EBL), and utilizing this we compute the allowed flux range for the EBL, which is independent of previous estimates. The observed VHE spectrum of the sources in our sample can be well approximated by a power law, and if the de-absorbed spectrum is also assumed to be a power law, then we show that the spectral shape of EBL will be ?n(?) ? klog (?/? {sub p}). We estimate the range of values for the parameters defining the EBL spectrum, k and ? {sub p}, such that the correlation of the intrinsic VHE spectrum with redshift is nullified. The estimated EBL depends only on the observed correlation and the assumption of a power-law source spectrum. Specifically, it does not depend on the spectral modeling or radiative mechanism of the sources or on any theoretical shape of the EBL spectrum obtained through cosmological calculations. The estimated EBL spectrum is consistent with the upper and lower limits imposed by different observations. Moreover, it also agrees closely with the theoretical estimates obtained through cosmological evolution models.

  7. Search for Stopped Gluinos in pp collisions at sqrt s = 7 TeV

    SciTech Connect (OSTI)

    Khachatryan, Vardan; et al.

    2011-01-01

    The results of the first search for long-lived gluinos produced in 7 TeV pp collisions at the CERN Large Hadron Collider are presented. The search looks for evidence of long-lived particles that stop in the CMS detector and decay in the quiescent periods between beam crossings. In a dataset with a peak instantaneous luminosity of 10^{32} cm^{-2} s^{-1}, an integrated luminosity of 10 inverse picobarns, and a search interval corresponding to 62 hours of LHC operation, no significant excess above background was observed. Limits at the 95% confidence level on gluino pair production over 13 orders of magnitude of gluino lifetime are set. For a mass difference between the gluino and the neutralino greater than 100 GeV/c^2, and assuming a branching ratio for gluino to gluon+neutralino of 100%, gluinos of mass less than 370 GeV/c^2 are excluded for lifetimes from 10 microseconds to 1000 s.

  8. Magnetic order tuned by Cu substitution in Fe1.1–zCuzTe

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

    Wen, Jinsheng; Xu, Zhijun; Xu, Guangyong; Lumsden, M. D.; Valdivia, P. N.; Bourret-Courchesne, E.; Gu, Genda; Lee, Dung-Hai; Tranquada, J. M.; Birgeneau, R. J.

    2012-07-02

    We study the effects of Cu substitution in Fe₁.₁Te, the nonsuperconducting parent compound of the iron-based superconductor, Fe₁₊yTe₁₋xSex, utilizing neutron scattering techniques. It is found that the structural and magnetic transitions, which occur at ~60 K without Cu, are monotonically depressed with increasing Cu content. By 10% Cu for Fe, the structural transition is hardly detectable, and the system becomes a spin glass below 22 K, with a slightly incommensurate ordering wave vector of (0.5–δ, 0, 0.5) with δ being the incommensurability of 0.02, and correlation length of 12 Å along the a axis and 9 Å along the cmore » axis. With 4% Cu, both transition temperatures are at 41 K, though short-range incommensurate order at (0.42, 0, 0.5) is present at 60 K. With further cooling, the incommensurability decreases linearly with temperature down to 37 K, below which there is a first-order transition to a long-range almost-commensurate antiferromagnetic structure. A spin anisotropy gap of 4.5 meV is also observed in this compound. Our results show that the weakly magnetic Cu has a large effect on the magnetic correlations; it is suggested that this is caused by the frustration of the exchange interactions between the coupled Fe spins.« less

  9. Empirical correlations between the arrhenius' parameters of impurities' diffusion coefficients in CdTe crystals

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

    Shcherbak, L.; Kopach, O.; Fochuk, P.; James, R. B.; Bolotnikov, A. E.

    2015-01-21

    Understanding of self- and dopant-diffusion in semiconductor devices is essential to our being able to assure the formation of well-defined doped regions. In this paper, we compare obtained in the literature up to date the Arrhenius’ parameters (D=D0exp(–ΔEa/kT)) of point-defect diffusion coefficients and the I-VII groups impurities in CdTe crystals and films. We found that in the diffusion process there was a linear dependence between the pre-exponential factor, D0, and the activation energy, ΔEa, of different species: This was evident in the self-diffusivity and isovalent impurity Hg diffusivity as well as for the dominant IIIA and IVA groups impurities andmore » Chlorine, except for the fast diffusing elements (e.g., Cu and Ag), chalcogens O, S, and Se, halogens I and Br as well as the transit impurities Mn, Co, Fe. As a result, reasons of the lack of correspondence of the data to compensative dependence are discussed.« less

  10. Measurement of event shapes in pp? collisions at ?s=1.96 TeV

    SciTech Connect (OSTI)

    Aaltonen, T.; lvarez Gonzlez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Apresyan, A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bauer, G.; Bedeschi, F.; Beecher, D.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Binkley, M.; Bisello, D.; Bizjak, I.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brau, B.; Brigliadori, L.; Brisuda, A.; Bromberg, C.; Brucken, E.; Bucciantonio, M.; Budagov, J.; Budd, H. S.; Budd, S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Canepa, A.; 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.; Chou, J. P.; Chung, W. H.; Chung, Y. S.; Ciobanu, C. I.; Ciocci, M. A.; Clark, A.; Compostella, G.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuenca Almenar, C.; Cuevas, J.; Culbertson, R.; Dagenhart, D.; dAscenzo, N.; Datta, M.; de Barbaro, P.; De Cecco, S.; De Lorenzo, G.; DellOrso, M.; Deluca, C.; Demortier, L.; Deng, J.; 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, D.; Errede, S.; Ershaidat, N.; Eusebi, R.; Fang, H. C.; Farrington, S.; Feindt, M.; Fernandez, J. P.; Ferrazza, C.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Funakoshi, Y.; Furic, I.; Gallinaro, M.; Galyardt, J.; 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.; Giunta, M.; 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.; Gresele, A.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Gunay-Unalan, Z.; Haber, C.; 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.; Hidas, D.; 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.; Jha, M. K.; Jindariani, S.; Johnson, W.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kamon, T.; Karchin, P. E.; Kato, Y.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, H. W.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kimura, N.; Kirby, M.; Klimenko, S.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Korytov, A.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Krumnack, N.; 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.; Lazzizzera, I.; LeCompte, T.; Lee, E.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Leo, S.; Leone, S.; Lewis, J. D.; Lin, C.-J.; Linacre, J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, Q.; Liu, T.; Lockwitz, S.; Lockyer, N. S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maeshima, K.; Makhoul, K.; Maksimovic, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Martnez, M.; Martnez-Ballarn, R.; Mastrandrea, P.; Mathis, M.; Mattson, M. E.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Menzione, A.; 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.; Norniella, O.; Nurse, E.; 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.

    2011-06-01

    A study of event-shape observables in proton-antiproton collisions at ?s=1.96??TeV is presented. The data for this analysis were recorded by the CDF II Detector at the Tevatron Collider. The variables studied are the transverse thrust and thrust minor, both defined in the plane perpendicular to the beam direction. The observables are measured using energies from unclustered calorimeter cells. In addition to studies of the differential distributions, we present the dependence of event-shape mean values on the leading-jet transverse energy. Data are compared with pythia Tune A and to resummed parton-level predictions that were matched to fixed-order results at next-to-leading-order (NLO) accuracy (NLO+NLL). Predictions from pythia Tune A agree fairly well with the data. However, the underlying event contributes significantly to these observables, making it difficult to make direct comparisons to the NLO+NLL predictions, which do not account for the underlying event. To overcome this difficulty, we introduce a new observable, a weighted difference of the mean values of the thrust and thrust minor, which is less sensitive to the underlying event, allowing for a comparison with NLO+NLL. Both pythia Tune A and the NLO+NLL calculations agree well within the 20% theoretical uncertainty with the data for this observable, indicating that perturbative QCD successfully describes shapes of the hadronic final states.

  11. Diffractive dijet production in p?p collisions at ?s=1.96 TeV

    SciTech Connect (OSTI)

    Aaltonen, T.; Albrow, M.; 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.

    2012-08-01

    We report on a study of diffractive dijet production in p?p collisions at s?=1.96 TeV using the CDF II detector at the Fermilab Tevatron p?p collider. A data sample from 310 pb? of integrated luminosity collected by triggering on a high transverse energy jet, EjetT, in coincidence with a recoil antiproton detected in a Roman pot spectrometer is used to measure the ratio of single-diffractive to inclusive-dijet event rates as a function of xp? of the interacting parton in the antiproton, the Bjorken-x, xp?Bj, and a Q?(EjetT) in the ranges 10?p?Bj<10? and 10p?<0.09 and a four-momentum transfer squared tp?>-4 GeV. The tp? dependence is measured as a function of Q and xp?Bj and compared with that of inclusive single diffraction dissociation. We find weak xp?Bj and Q dependencies in the ratio of single diffractive to inclusive event rates, and no significant Q dependence in the diffractive tp? distributions.

  12. Strong lensing probability in TeVeS (tensor-vector-scalar) theory

    SciTech Connect (OSTI)

    Chen Daming

    2008-01-15

    We recalculate the strong lensing probability as a function of the image separation in TeVeS (tensor-vector-scalar) cosmology, which is a relativistic version of MOND (MOdified Newtonian Dynamics). The lens is modeled by the Hernquist profile. We assume an open cosmology with {Omega}{sub b} = 0.04 and {Omega}{sub {Lambda}} = 0.5 and three different kinds of interpolating functions. Two different galaxy stellar mass functions (GSMF) are adopted: PHJ (Panter, Heavens and Jimenez 2004 Mon. Not. R. Astron. Soc. 355 764) determined from SDSS data release 1 and Fontana (Fontana et al 2006 Astron. Astrophys. 459 745) from GOODS-MUSIC catalog. We compare our results with both the predicted probabilities for lenses from singular isothermal sphere galaxy halos in LCDM (Lambda cold dark matter) with a Schechter-fit velocity function, and the observational results for the well defined combined sample of the Cosmic Lens All-Sky Survey (CLASS) and Jodrell Bank/Very Large Array Astrometric Survey (JVAS). It turns out that the interpolating function {mu}(x) = x/(1+x) combined with Fontana GSMF matches the results from CLASS/JVAS quite well.

  13. Inclusive b-jet production in pp collisions at sqrt(s)=7 TeV

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; et al.

    2012-04-01

    The inclusive b-jet production cross section in pp collisions at a center-of-mass energy of 7 TeV is measured using data collected by the CMS experiment at the LHC. The cross section is presented as a function of the jet transverse momentum in the range 18 < pT < 200 GeV for several rapidity intervals. The results are also given as the ratio of the b-jet production cross section to the inclusive jet production cross section. The measurement is performed with two different analyses, which differ in their trigger selection and b-jet identification: a jet analysis that selects events with a b jet using a sample corresponding to an integrated luminosity of 34 inverse picobarns, and a muon analysis requiring a b jet with a muon based on an integrated luminosity of 3 inverse picobarns. In both approaches the b jets are identified by requiring a secondary vertex. The results from the two methods are in agreement with each other and with next-to-leading order calculations, as well as with predictions based on the PYTHIA event generator.

  14. Search for physics beyond the standard model in dilepton mass spectra in proton-proton collisions at ? = 8 TeV

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

    Khachatryan, Vardan

    2015-04-07

    Dimuon and dielectron mass spectra, obtained from data resulting from proton-proton collisions at 8 TeV and recorded by the CMS experiment, are used to search for both narrow resonances and broad deviations from standard model predictions. The data correspond to an integrated luminosity of 20.6 (19.7) fb? for the dimuon (dielectron) channel. No evidence for non-standard-model physics is observed and 95% confidence level limits are set on parameters from a number of new physics models. The narrow resonance analyses exclude a Sequential Standard Model Z'SSM resonance lighter than 2.90 TeV, a superstring-inspired Z'? lighter than 2.57 TeV and Randall-SundrummoreKaluza-Klein gravitons with masses below 2.73, 2.35, and 1.27 TeV for couplings of 0.10, 0.05, and 0.01, respectively. A notable feature is that the limits have been calculated in a model-independent way to enable straightforward reinterpretation in any model predicting a resonance structure. The observed events are also interpreted within the framework of two non-resonant analyses: one based on a large extra dimensions model and one based on a quark and lepton compositeness model with a left-left isoscalar contact interaction. Lower limits are established on MS, the scale characterizing the onset of quantum gravity, which range from 4.9 to 3.3 TeV, where the number of additional spatial dimensions varies from 3 to 7. Similarly, lower limits on ?, the energy scale parameter for the contact interaction, are found to be 12.0 (15.2) TeV for destructive (constructive) interference in the dimuon channel and 13.5 (18.3) TeV in the dielectron channel.less

  15. Search for physics beyond the standard model in dilepton mass spectra in proton-proton collisions at ? = 8 TeV

    SciTech Connect (OSTI)

    Khachatryan, Vardan

    2015-04-07

    Dimuon and dielectron mass spectra, obtained from data resulting from proton-proton collisions at 8 TeV and recorded by the CMS experiment, are used to search for both narrow resonances and broad deviations from standard model predictions. The data correspond to an integrated luminosity of 20.6 (19.7) fb? for the dimuon (dielectron) channel. No evidence for non-standard-model physics is observed and 95% confidence level limits are set on parameters from a number of new physics models. The narrow resonance analyses exclude a Sequential Standard Model Z'SSM resonance lighter than 2.90 TeV, a superstring-inspired Z'? lighter than 2.57 TeV and Randall-Sundrum Kaluza-Klein gravitons with masses below 2.73, 2.35, and 1.27 TeV for couplings of 0.10, 0.05, and 0.01, respectively. A notable feature is that the limits have been calculated in a model-independent way to enable straightforward reinterpretation in any model predicting a resonance structure. The observed events are also interpreted within the framework of two non-resonant analyses: one based on a large extra dimensions model and one based on a quark and lepton compositeness model with a left-left isoscalar contact interaction. Lower limits are established on MS, the scale characterizing the onset of quantum gravity, which range from 4.9 to 3.3 TeV, where the number of additional spatial dimensions varies from 3 to 7. Similarly, lower limits on ?, the energy scale parameter for the contact interaction, are found to be 12.0 (15.2) TeV for destructive (constructive) interference in the dimuon channel and 13.5 (18.3) TeV in the dielectron channel.

  16. Search for new phenomena with photon+jet events in proton-proton collisions at √s = 13 TeV with the ATLAS detector

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

    Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Aben, R.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; et al

    2016-03-08

    A search is performed for the production of high-mass resonances decaying into a photon and a jet in 3.2 fb-1 of proton-proton collisions at a centre-of-mass energy of √s =13 TeV collected by the ATLAS detector at the Large Hadron Collider. Selected events have an isolated photon and a jet, each with transverse momentum above 150 GeV. No significant deviation of the γ+jet invariant mass distribution from the background-only hypothesis is found. Limits are set at 95% confidence level on the cross sections of generic Gaussian-shaped signals and of a few benchmark phenomena beyond the Standard Model: excited quarks withmore » vector-like couplings to the Standard Model particles, and non-thermal quantum black holes in two models of extra spatial dimensions. The minimum excluded visible cross sections for Gaussian-shaped resonances with width-to-mass ratios of 2% decrease from about 6 fb for a mass of 1.5 TeV to about 0.8 fb for a mass of 5 TeV. The minimum excluded visible cross sections for Gaussian-shaped resonances with width-to-mass ratios of 15% decrease from about 50 fb for a mass of 1.5 TeV to about 1.0 fb for a mass of 5 TeV. As a result, excited quarks are excluded below masses of 4.4 TeV, and non-thermal quantum black holes are excluded below masses of 3.8 (6.2) TeV for Randall-Sundrum (Arkani-Hamed-Dimopoulous-Dvali) models with one (six) extra dimensions.« less

  17. Search for physics beyond the standard model in dilepton mass spectra in proton-proton collisions at √s = 8 TeV

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

    Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; et al

    2015-04-07

    Dimuon and dielectron mass spectra, obtained from data resulting from proton-proton collisions at 8 TeV and recorded by the CMS experiment, are used to search for both narrow resonances and broad deviations from standard model predictions. The data correspond to an integrated luminosity of 20.6 (19.7) fb–1 for the dimuon (dielectron) channel. No evidence for non-standard-model physics is observed and 95% confidence level limits are set on parameters from a number of new physics models. The narrow resonance analyses exclude a Sequential Standard Model Z SSM ' resonance lighter than 2.90 TeV, a superstring-inspired Z ψ ' lighter than 2.57more » TeV, and Randall-Sundrum Kaluza-Klein gravitons with masses below 2.73, 2.35, and 1.27 TeV for couplings of 0.10, 0.05, and 0.01, respectively. A notable feature is that the limits have been calculated in a model-independent way to enable straightforward reinterpretation in any model predicting a resonance structure. The observed events are also interpreted within the framework of two non-resonant analyses: one based on a large extra dimensions model and one based on a quark and lepton compositeness model with a left-left isoscalar contact interaction. Lower limits are established on MS, the scale characterizing the onset of quantum gravity, which range from 4.9 to 3.3 TeV, where the number of additional spatial dimensions varies from 3 to 7. Thus lower limits on Λ, the energy scale parameter for the contact interaction, are found to be 12.0 (15.2) TeV for destructive (constructive) interference in the dimuon channel and 13.5 (18.3) TeV in the dielectron channel.« less

  18. Search for physics beyond the standard model in dilepton mass spectra in proton-proton collisions at ?s = 8 TeV

    SciTech Connect (OSTI)

    Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Er, J.; Fabjan, C.; Friedl, M.; Frhwirth, R.; Ghete, V. M.; Hartl, C.; Hrmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knnz, V.; Krammer, M.; Krtschmer, I.; Liko, D.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, H.; Schfbeck, R.; Strauss, J.; Taurok, A.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C. -E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Bansal, M.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Knutsson, A.; Luyckx, S.; Ochesanu, S.; Rougny, R.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; DHondt, J.; Daci, N.; Heracleous, N.; Keaveney, J.; Lowette, S.; Maes, M.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Caillol, C.; Clerbaux, B.; De Lentdecker, G.; Dobur, D.; Favart, L.; Gay, A. P. R.; Grebenyuk, A.; Lonard, A.; Mohammadi, A.; Perni, L.; Reis, T.; Seva, T.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Zenoni, F.; Adler, V.; Beernaert, K.; Benucci, L.; Cimmino, A.; Costantini, S.; Crucy, S.; Dildick, S.; Fagot, A.; Garcia, G.; Mccartin, J.; Ocampo Rios, A. A.; Ryckbosch, D.; Salva Diblen, S.; Sigamani, M.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bruno, G.; Castello, R.; Caudron, A.; Ceard, L.; Da Silveira, G. G.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jafari, A.; Jez, P.; Komm, M.; Lemaitre, V.; Nuttens, C.; Pagano, D.; Perrini, L.; Pin, A.; Piotrzkowski, K.; Popov, A.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Vizan Garcia, J. M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Ald Jnior, W. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Dos Reis Martins, T.; Mora Herrera, C.; Pol, M. E.; Carvalho, W.; Chinellato, J.; Custdio, A.; Da Costa, E. 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F.; Bernet, C.; Bloch, P.; Bocci, A.; Bonato, A.; Bondu, O.; Botta, C.; Breuker, H.; Camporesi, T.; Cerminara, G.; Colafranceschi, S.; DAlfonso, M.; dEnterria, D.; Dabrowski, A.; David, A.; De Guio, F.; De Roeck, A.; De Visscher, S.; Di Marco, E.; Dobson, M.; Dordevic, M.; Dorney, B.; Dupont-Sagorin, N.; Elliott-Peisert, A.; Eugster, J.; Franzoni, G.; Funk, W.; Gigi, D.; Gill, K.; Giordano, D.; Girone, M.; Glege, F.; Guida, R.; Gundacker, S.; Guthoff, M.; Hammer, J.; Hansen, M.; Harris, P.; Hegeman, J.; Innocente, V.; Janot, P.; Kousouris, K.; Krajczar, K.; Lecoq, P.; Loureno, C.; Magini, N.; Malgeri, L.; Mannelli, M.; Marrouche, J.; Masetti, L.; Meijers, F.; Mersi, S.; Meschi, E.; Moortgat, F.; Morovic, S.; Mulders, M.; Musella, P.; Orsini, L.; Pape, L.; Perez, E.; Perrozzi, L.; Petrilli, A.; Petrucciani, G.; Pfeiffer, A.; Pierini, M.; Pimi, M.; Piparo, D.; Plagge, M.; Racz, A.; Rolandi, G.; Rovere, M.; Sakulin, H.; Schfer, C.; Schwick, C.; Sharma, A.; Siegrist, P.; Silva, P.; Simon, M.; Sphicas, P.; Spiga, D.; Steggemann, J.; Stieger, B.; Stoye, M.; Takahashi, Y.; Treille, D.; Tsirou, A.; Veres, G. I.; Wardle, N.; Whri, H. K.; Wollny, H.; Zeuner, W. D.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H. C.; Kotlinski, D.; Langenegger, U.; Renker, D.; Rohe, T.; Bachmair, F.; Bni, L.; Bianchini, L.; Buchmann, M. A.; Casal, B.; Chanon, N.; Dissertori, G.; Dittmar, M.; Doneg, M.; Dnser, M.; Eller, P.; Grab, C.; Hits, D.; Hoss, J.; Lustermann, W.; Mangano, B.; Marini, A. C.; Martinez Ruiz del Arbol, P.; Masciovecchio, M.; Meister, D.; Mohr, N.; Ngeli, C.; Nessi-Tedaldi, F.; Pandolfi, F.; Pauss, F.; Peruzzi, M.; Quittnat, M.; Rebane, L.; Rossini, M.; Starodumov, A.; Takahashi, M.; Theofilatos, K.; Wallny, R.; Weber, H. A.; Amsler, C.; Canelli, M. F.; Chiochia, V.; De Cosa, A.; Hinzmann, A.; Hreus, T.; Kilminster, B.; Lange, C.; Millan Mejias, B.; Ngadiuba, J.; Robmann, P.; Ronga, F. J.; Taroni, S.; Verzetti, M.; Yang, Y.; Cardaci, M.; Chen, K. H.; Ferro, C.; Kuo, C. M.; Lin, W.; Lu, Y. J.; Volpe, R.; Yu, S. S.; Chang, P.; Chang, Y. H.; Chang, Y. W.; Chao, Y.; Chen, K. F.; Chen, P. H.; Dietz, C.; Grundler, U.; Hou, W. -S.; Kao, K. Y.; Lei, Y. J.; Liu, Y. F.; Lu, R. -S.; Majumder, D.; Petrakou, E.; Tzeng, Y. M.; Wilken, R.; Asavapibhop, B.; Singh, G.; Srimanobhas, N.; Suwonjandee, N.; Adiguzel, A.; Bakirci, M. N.; Cerci, S.; Dozen, C.; Dumanoglu, I.; Eskut, E.; Girgis, S.; Gokbulut, G.; Gurpinar, E.; Hos, I.; Kangal, E. E.; Kayis Topaksu, A.; Onengut, G.; Ozdemir, K.; Ozturk, S.; Polatoz, A.; Sunar Cerci, D.; Tali, B.; Topakli, H.; Vergili, M.; Akin, I. V.; Bilin, B.; Bilmis, S.; Gamsizkan, H.; Karapinar, G.; Ocalan, K.; Sekmen, S.; Surat, U. E.; Yalvac, M.; Zeyrek, M.; Glmez, E.; Isildak, B.; Kaya, M.; Kaya, O.; Cankocak, K.; Vardarl?, F. I.; Levchuk, L.; Sorokin, P.; Brooke, J. J.; Clement, E.; Cussans, D.; Flacher, H.; Goldstein, J.; Grimes, M.; Heath, G. P.; Heath, H. F.; Jacob, J.; Kreczko, L.; Lucas, C.; Meng, Z.; Newbold, D. M.; Paramesvaran, S.; Poll, A.; Senkin, S.; Smith, V. J.; Williams, T.; Bell, K. W.; Belyaev, A.; Brew, C.; Brown, R. M.; Cockerill, D. J. A.; Coughlan, J. A.; Harder, K.; Harper, S.; Olaiya, E.; Petyt, D.; Shepherd-Themistocleous, C. H.; Thea, A.; Tomalin, I. R.; Womersley, W. J.; Worm, S. D.; Baber, M.; Bainbridge, R.; Buchmuller, O.; Burton, D.; Colling, D.; Cripps, N.; Cutajar, M.; Dauncey, P.; Davies, G.; Della Negra, M.; Dunne, P.; Ferguson, W.; Fulcher, J.; Futyan, D.; Gilbert, A.; Hall, G.; Iles, G.; Jarvis, M.; Karapostoli, G.; Kenzie, M.; Lane, R.; Lucas, R.; Lyons, L.; Magnan, A. -M.; Malik, S.; Mathias, B.; Nash, J.; Nikitenko, A.; Pela, J.; Pesaresi, M.; Petridis, K.; Raymond, D. M.; Rogerson, S.; Rose, A.; Seez, C.; Sharp, P.; Tapper, A.; Vazquez Acosta, M.; Virdee, T.; Zenz, S. C.; Cole, J. E.; Hobson, P. R.; Khan, A.; Kyberd, P.; Leggat, D.; Leslie, D.; Martin, W.; Reid, I. D.; Symonds, P.; Teodorescu, L.; Turner, M.; Dittmann, J.; Hatakeyama, K.; Kasmi, A.; Liu, H.; Scarborough, T.; Charaf, O.; Cooper, S. I.; Henderson, C.; Rumerio, P.; Avetisyan, A.; Bose, T.; Fantasia, C.; Lawson, P.; Richardson, C.; Rohlf, J.; John, J. St.; Sulak, L.; Alimena, J.; Berry, E.; Bhattacharya, S.; Christopher, G.; Cutts, D.; Demiragli, Z.; Dhingra, N.; Ferapontov, A.; Garabedian, A.; Heintz, U.; Kukartsev, G.; Laird, E.; Landsberg, G.; Luk, M.; Narain, M.; Segala, M.; Sinthuprasith, T.; Speer, T.; Swanson, J.; Breedon, R.; Breto, G.; Calderon De La Barca Sanchez, M.; Chauhan, S.; Chertok, M.; Conway, J.; Conway, R.; Cox, P. T.; Erbacher, R.; Gardner, M.; Ko, W.; Lander, R.; Miceli, T.; Mulhearn, M.; Pellett, D.; Pilot, J.; Ricci-Tam, F.; Searle, M.; Shalhout, S.; Smith, J.; Squires, M.; Stolp, D.; Tripathi, M.; Wilbur, S.; Yohay, R.; Cousins, R.; Everaerts, P.; Farrell, C.; Hauser, J.; Ignatenko, M.; Rakness, G.; Takasugi, E.; Valuev, V.; Weber, M.; Burt, K.; Clare, R.; Ellison, J.; Gary, J. W.; Hanson, G.; Heilman, J.; Ivova Rikova, M.; Jandir, P.; Kennedy, E.; Lacroix, F.; Long, O. R.; Luthra, A.; Malberti, M.; Nguyen, H.; Olmedo Negrete, M.; Shrinivas, A.; Sumowidagdo, S.; Wimpenny, S.; Andrews, W.; Branson, J. G.; Cerati, G. B.; Cittolin, S.; DAgnolo, R. T.; Evans, D.; Holzner, A.; Kelley, R.; Klein, D.; Lebourgeois, M.; Letts, J.; Macneill, I.; Olivito, D.; Padhi, S.; Palmer, C.; Pieri, M.; Sani, M.; Sharma, V.; Simon, S.; Sudano, E.; Tadel, M.; Tu, Y.; Vartak, A.; Welke, C.; Wrthwein, F.; Yagil, A.; Barge, D.; Bradmiller-Feld, J.; Campagnari, C.; Danielson, T.; Dishaw, A.; Dutta, V.; Flowers, K.; Franco Sevilla, M.; Geffert, P.; George, C.; Golf, F.; Gouskos, L.; Incandela, J.; Justus, C.; Mccoll, N.; Richman, J.; Stuart, D.; To, W.; West, C.; Yoo, J.; Apresyan, A.; Bornheim, A.; Bunn, J.; Chen, Y.; Duarte, J.; Mott, A.; Newman, H. B.; Pena, C.; Rogan, C.; Spiropulu, M.; Timciuc, V.; Vlimant, J. R.; Wilkinson, R.; Xie, S.; Zhu, R. Y.; Azzolini, V.; Calamba, A.; Carlson, B.; Ferguson, T.; Iiyama, Y.; Paulini, M.; Russ, J.; Vogel, H.; Vorobiev, I.; Cumalat, J. P.; Ford, W. T.; Gaz, A.; Luiggi Lopez, E.; Nauenberg, U.; Smith, J. G.; Stenson, K.; Ulmer, K. A.; Wagner, S. R.; Alexander, J.; Chatterjee, A.; Chu, J.; Dittmer, S.; Eggert, N.; Mirman, N.; Nicolas Kaufman, G.; Patterson, J. R.; Ryd, A.; Salvati, E.; Skinnari, L.; Sun, W.; Teo, W. D.; Thom, J.; Thompson, J.; Tucker, J.; Weng, Y.; Winstrom, L.; Wittich, P.; Winn, D.; Abdullin, S.; Albrow, M.; Anderson, J.; Apollinari, G.; Bauerdick, L. A. T.; Beretvas, A.; Berryhill, J.; Bhat, P. C.; Bolla, G.; Burkett, K.; Butler, J. N.; Cheung, H. W. K.; Chlebana, F.; Cihangir, S.; Elvira, V. D.; Fisk, I.; Freeman, J.; Gao, Y.; Gottschalk, E.; Gray, L.; Green, D.; Grnendahl, S.; Gutsche, O.; Hanlon, J.; Hare, D.; Harris, R. M.; Hirschauer, J.; Hooberman, B.; Jindariani, S.; Johnson, M.; Joshi, U.; Kaadze, K.; Klima, B.; Kreis, B.; Kwan, S.; Linacre, J.; Lincoln, D.; Lipton, R.; Liu, T.; Lykken, J.; Maeshima, K.; Marraffino, J. M.; Martinez Outschoorn, V. I.; Maruyama, S.; Mason, D.; McBride, P.; Merkel, P.; Mishra, K.; Mrenna, S.; Musienko, Y.; Nahn, S.; Newman-Holmes, C.; ODell, V.; Prokofyev, O.; Sexton-Kennedy, E.; Sharma, S.; Soha, A.; Spalding, W. J.; Spiegel, L.; Taylor, L.; Tkaczyk, S.; Tran, N. V.; Uplegger, L.; Vaandering, E. W.; Vidal, R.; Whitbeck, A.; Whitmore, J.; Yang, F.; Acosta, D.; Avery, P.; Bortignon, P.; Bourilkov, D.; Carver, M.; Cheng, T.; Curry, D.; Das, S.; De Gruttola, M.; Di Giovanni, G. P.; Field, R. D.; Fisher, M.; Furic, I. K.; Hugon, J.; Konigsberg, J.; Korytov, A.; Kypreos, T.; Low, J. F.; Matchev, K.; Milenovic, P.; Mitselmakher, G.; Muniz, L.; Rinkevicius, A.; Shchutska, L.; Snowball, M.; Sperka, D.; Yelton, J.; Zakaria, M.; Hewamanage, S.; Linn, S.; Markowitz, P.; Martinez, G.; Rodriguez, J. L.; Adams, T.; Askew, A.; Bochenek, J.; Diamond, B.; Haas, J.; Hagopian, S.; Hagopian, V.; Johnson, K. F.; Prosper, H.; Veeraraghavan, V.; Weinberg, M.; Baarmand, M. M.; Hohlmann, M.; Kalakhety, H.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Bazterra, V. E.; Berry, D.; Betts, R. R.; Bucinskaite, I.; Cavanaugh, R.; Evdokimov, O.; Gauthier, L.; Gerber, C. E.; Hofman, D. J.; Khalatyan, S.; Kurt, P.; Moon, D. H.; OBrien, C.; Silkworth, C.; Turner, P.; Varelas, N.; Albayrak, E. A.; Bilki, B.; Clarida, W.; Dilsiz, K.; Duru, F.; Haytmyradov, M.; Merlo, J. -P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Rahmat, R.; Sen, S.; Tan, P.; Tiras, E.; Wetzel, J.; Yetkin, T.; Yi, K.; Barnett, B. A.; Blumenfeld, B.; Bolognesi, S.; Fehling, D.; Gritsan, A. V.; Maksimovic, P.; Martin, C.; Swartz, M.; Baringer, P.; Bean, A.; Benelli, G.; Bruner, C.; Kenny, R. P.; Malek, M.; Murray, M.; Noonan, D.; Sanders, S.; Sekaric, J.; Stringer, R.; Wang, Q.; Wood, J. S.; Chakaberia, I.; Ivanov, A.; Khalil, S.; Makouski, M.; Maravin, Y.; Saini, L. K.; Shrestha, S.; Skhirtladze, N.; Svintradze, I.; Gronberg, J.; Lange, D.; Rebassoo, F.; Wright, D.; Baden, A.; Belloni, A.; Calvert, B.; Eno, S. C.; Gomez, J. A.; Hadley, N. J.; Kellogg, R. G.; Kolberg, T.; Lu, Y.; Marionneau, M.; Mignerey, A. C.; Pedro, K.; Skuja, A.; Tonjes, M. B.; Tonwar, S. C.; Apyan, A.; Barbieri, R.; Bauer, G.; Busza, W.; Cali, I. A.; Chan, M.; Di Matteo, L.; Gomez Ceballos, G.; Goncharov, M.; Gulhan, D.; Klute, M.; Lai, Y. S.; Lee, Y. -J.; Levin, A.; Luckey, P. D.; Ma, T.; Paus, C.; Ralph, D.; Roland, C.; Roland, G.; Stephans, G. S. F.; Stckli, F.; Sumorok, K.; Velicanu, D.; Veverka, J.; Wyslouch, B.; Yang, M.; Zanetti, M.; Zhukova, V.; Dahmes, B.; Gude, A.; Kao, S. C.; Klapoetke, K.; Kubota, Y.; Mans, J.; Pastika, N.; Rusack, R.; Singovsky, A.; Tambe, N.; Turkewitz, J.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bloom, K.; Bose, S.; Claes, D. R.; Dominguez, A.; Gonzalez Suarez, R.; Keller, J.; Knowlton, D.; Kravchenko, I.; Lazo-Flores, J.; Malik, S.; Meier, F.; Snow, G. R.; Zvada, M.; Dolen, J.; Godshalk, A.; Iashvili, I.; Kharchilava, A.; Kumar, A.; Rappoccio, S.; Alverson, G.; Barberis, E.; Baumgartel, D.; Chasco, M.; Haley, J.; Massironi, A.; Morse, D. M.; Nash, D.; Orimoto, T.; Trocino, D.; Wang, R. -J.; Wood, D.; Zhang, J.; Hahn, K. A.; Kubik, A.; Mucia, N.; Odell, N.; Pollack, B.; Pozdnyakov, A.; Schmitt, M.; Stoynev, S.; Sung, K.; Velasco, M.; Won, S.; Brinkerhoff, A.; Chan, K. M.; Drozdetskiy, A.; Hildreth, M.; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Luo, W.; Lynch, S.; Marinelli, N.; Pearson, T.; Planer, M.; Ruchti, R.; Valls, N.; Wayne, M.; Wolf, M.; Woodard, A.; Antonelli, L.; Brinson, J.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Hart, A.; Hill, C.; Hughes, R.; Kotov, K.; Ling, T. Y.; Puigh, D.; Rodenburg, M.; Smith, G.; Winer, B. L.; Wolfe, H.; Wulsin, H. W.; Driga, O.; Elmer, P.; Hebda, P.; Hunt, A.; Koay, S. A.; Lujan, P.; Marlow, D.; Medvedeva, T.; Mooney, M.; Olsen, J.; Pirou, P.; Quan, X.; Saka, H.; Stickland, D.; Tully, C.; Werner, J. S.; Zuranski, A.; Brownson, E.; Mendez, H.; Ramirez Vargas, J. E.; Barnes, V. E.; Benedetti, D.; Bortoletto, D.; De Mattia, M.; Gutay, L.; Hu, Z.; Jha, M. K.; Jones, M.; Jung, K.; Kress, M.; Leonardo, N.; Lopes Pegna, D.; Maroussov, V.; Miller, D. H.; Neumeister, N.; Radburn-Smith, B. C.; Shi, X.; Shipsey, I.; Silvers, D.; Svyatkovskiy, A.; Wang, F.; Xie, W.; Xu, L.; Zablocki, J.; Zheng, Y.; Parashar, N.; Stupak, J.; Adair, A.; Akgun, B.; Ecklund, K. M.; Geurts, F. J. M.; Li, W.; Michlin, B.; Padley, B. P.; Redjimi, R.; Roberts, J.; Zabel, J.; Betchart, B.; Bodek, A.; Covarelli, R.; de Barbaro, P.; Demina, R.; Eshaq, Y.; Ferbel, T.; Garcia-Bellido, A.; Goldenzweig, P.; Han, J.; Harel, A.; Khukhunaishvili, A.; Petrillo, G.; Vishnevskiy, D.; Ciesielski, R.; Demortier, L.; Goulianos, K.; Lungu, G.; Mesropian, C.; Arora, S.; Barker, A.; Chou, J. P.; Contreras-Campana, C.; Contreras-Campana, E.; Duggan, D.; Ferencek, D.; Gershtein, Y.; Gray, R.; Halkiadakis, E.; Hidas, D.; Kaplan, S.; Lath, A.; Panwalkar, S.; Park, M.; Patel, R.; Salur, S.; Schnetzer, S.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Rose, K.; Spanier, S.; York, A.; Bouhali, O.; Castaneda Hernandez, A.; Eusebi, R.; Flanagan, W.; Gilmore, J.; Kamon, T.; Khotilovich, V.; Krutelyov, V.; Montalvo, R.; Osipenkov, I.; Pakhotin, Y.; Perloff, A.; Roe, J.; Rose, A.; Safonov, A.; Sakuma, T.; Suarez, I.; Tatarinov, A.; Akchurin, N.; Cowden, C.; Damgov, J.; Dragoiu, C.; Dudero, P. R.; Faulkner, J.; Kovitanggoon, K.; Kunori, S.; Lee, S. W.; Libeiro, T.; Volobouev, I.; Appelt, E.; Delannoy, A. G.; Greene, S.; Gurrola, A.; Johns, W.; Maguire, C.; Mao, Y.; Melo, A.; Sharma, M.; Sheldon, P.; Snook, B.; Tuo, S.; Velkovska, J.; Arenton, M. W.; Boutle, S.; Cox, B.; Francis, B.; Goodell, J.; Hirosky, R.; Ledovskoy, A.; Li, H.; Lin, C.; Neu, C.; Wood, J.; Clarke, C.; Harr, R.; Karchin, P. E.; Kottachchi Kankanamge Don, C.; Lamichhane, P.; Sturdy, J.; Belknap, D. A.; Carlsmith, D.; Cepeda, M.; Dasu, S.; Dodd, L.; Duric, S.; Friis, E.; Hall-Wilton, R.; Herndon, M.; Herv, A.; Klabbers, P.; Lanaro, A.; Lazaridis, C.; Levine, A.; Loveless, R.; Mohapatra, A.; Ojalvo, I.; Perry, T.; Pierro, G. A.; Polese, G.; Ross, I.; Sarangi, T.; Savin, A.; Smith, W. H.; Taylor, D.; Verwilligen, P.; Vuosalo, C.; Woods, N.

    2015-04-07

    Dimuon and dielectron mass spectra, obtained from data resulting from proton-proton collisions at 8 TeV and recorded by the CMS experiment, are used to search for both narrow resonances and broad deviations from standard model predictions. The data correspond to an integrated luminosity of 20.6 (19.7) fb1 for the dimuon (dielectron) channel. No evidence for non-standard-model physics is observed and 95% confidence level limits are set on parameters from a number of new physics models. The narrow resonance analyses exclude a Sequential Standard Model Z SSM ' resonance lighter than 2.90 TeV, a superstring-inspired Z ? ' lighter than 2.57 TeV, and Randall-Sundrum Kaluza-Klein gravitons with masses below 2.73, 2.35, and 1.27 TeV for couplings of 0.10, 0.05, and 0.01, respectively. A notable feature is that the limits have been calculated in a model-independent way to enable straightforward reinterpretation in any model predicting a resonance structure. The observed events are also interpreted within the framework of two non-resonant analyses: one based on a large extra dimensions model and one based on a quark and lepton compositeness model with a left-left isoscalar contact interaction. Lower limits are established on MS, the scale characterizing the onset of quantum gravity, which range from 4.9 to 3.3 TeV, where the number of additional spatial dimensions varies from 3 to 7. Thus lower limits on ?, the energy scale parameter for the contact interaction, are found to be 12.0 (15.2) TeV for destructive (constructive) interference in the dimuon channel and 13.5 (18.3) TeV in the dielectron channel.

  19. RTGs Using PbTe/TAGSThermoelectric Elements for Mars Environmentatl Survey (MESUR) Mission

    SciTech Connect (OSTI)

    Schock, Alfred

    1992-07-01

    The paper describes the results of studies on an RTG option for powering the global network of unmanned landers for NASA's Mars Environmental Survey (MESUR) mission. RTGs are essentially unaffected by diurnal and seasonal variations, Martian sandstorms, and landing site latitudes, and their waste heat can stabilize the temperatures of the landers and their payload. The RTG designs described in this paper are based on PbTe/TAGS Thermoelectric elements, in contrast to the SiGe-based RTGs the author described in previous publications. The RTGs described here differ not only in the choice of thermoelectric materials but also in the use of much lower operating temperatures, conductive rather than radiative heat transfer, an inert cover gas instead of vacuum in the RGG's converter, and fibrous instead of multifoil thermal insulation. As in a previous Teledyne design, the Fairchild designs described in this paper employ flight-proven General Purpose Heat Source modules and Close-Pack Arrays of thermoelectric converter modules. Illustrative point designs of RTGs producing 41 and 51 watts(e) at 28 volts are presented. The presented performance parameters were derived by detailed thermal, thermoelectric, and electrical analyses (including radiator geometry optimization) described in the paper. The Fairchild study resulted in modifications of the Teledyne design to permit scale-up to higher power levels, and to ensure adequate fuel clad ductility at launch temperatures and adequate thermal conductance from the thermoelectric cold ends to the RTG housing. There are three duplicate copies. One copy is in the FSC-ESD files.

  20. The Present, Mid-Term, and Long-Term Supply Curves for Tellurium; and Updates in the Results from NREL's CdTe PV Module Manufacturing Cost Model (Presentation)

    SciTech Connect (OSTI)

    Woodhouse, M.; Goodrich, A.; Redlinger, M.; Lokanc, M.; Eggert, R.

    2013-09-01

    For those PV technologies that rely upon Te, In, and Ga, first-order observations and calculations hint that there may be resource constraints that could inhibit their successful deployment at a SunShot level. These are only first-order approximations, however, and the possibility for an expansion in global Te, In, and Ga supplies needs to be considered in the event that there are upward revisions in their demand and prices.In this study, we examine the current, mid-term, and long-term prospects of Tellurium (Te) for use in PV. We find that the current global supply base of Te would support <10 GW of annual traditional CdTe PV manufacturing production. But as for the possibility that the supply base for Te might be expanded, after compiling several preliminary cumulative availability curves we find that there may be significant upside potential in the supply base for this element - principally vis a vis increasing demand and higher prices. Primarily by reducing the Tellurium intensity in manufacturing and by increasing the recovery efficiency of Te in Cu refining processes, we calculate that it may prove affordable to PV manufacturers to expand the supply base for Te such that 100 GW, or greater, of annual CdTe PV production is possible in the 2030 - 2050 timeframe.

  1. Measurement of differential cross sections for the production of a pair of isolated photons in pp collisions at $$\\sqrt{s}=7\\,\\text {TeV} $$ s = 7 TeV

    SciTech Connect (OSTI)

    Chatrchyan, Serguei

    2014-11-12

    A measurement of differential cross sections for the production of a pair of isolated photons in protonproton collisions at $\\sqrt{s}=7\\,\\text {TeV} $ is presented. The data sample corresponds to an integrated luminosity of 5.0 $\\,\\text {fb}^{-1}$ collected with the CMS detector. A data-driven isolation template method is used to extract the prompt diphoton yield. The measured cross section for two isolated photons, with transverse energy above 40 and 25 $\\,\\text {GeV}$ respectively, in the pseudorapidity range $|\\eta |<2.5$ , $|\\eta |\

  2. High-temperature order-disorder transitions in the skutterudites CoGe{sub 1.5}Q{sub 1.5} (Q=S, Te)

    SciTech Connect (OSTI)

    Kaltzoglou, Andreas; Powell, Anthony V.; Knight, Kevin S.; Vaqueiro, Paz

    2013-02-15

    The temperature dependence of anion ordering in the skutterudites CoGe{sub 1.5}Q{sub 1.5} (Q=S, Te) has been investigated by powder neutron diffraction. Both materials adopt a rhombohedral structure at room temperature (space group R3{sup Macron} ) in which the anions are ordered trans to each other within Ge{sub 2}Q{sub 2} rings. In CoGe{sub 1.5}S{sub 1.5}, anion ordering is preserved up to the melting point of 950 Degree-Sign C. However, rhombohedral CoGe{sub 1.5}Te{sub 1.5} undergoes a phase transition at 610 Degree-Sign C involving a change to cubic symmetry (space group Im3{sup Macron }). In the high-temperature modification, there is a statistical distribution of anions over the available sites within the Ge{sub 2}Te{sub 2} rings. The structural transition involves a reduction in the degree of distortion of the Ge{sub 2}Te{sub 2} rings which progressively transform from a rhombus to a rectangular shape. The effect of this transition on the thermoelectric properties has been investigated. - Graphical abstract: Powder neutron diffraction reveals that the skutterudite CoGe{sub 1.5}Te{sub 1.5} undergoes a phase transition at 610 Degree-Sign C, involving the disordering of the anions within the Ge{sub 2}Te{sub 2} rings. Highlights: Black-Right-Pointing-Pointer CoGe{sub 1.5}S{sub 1.5} retains an ordered skutterudite structure up to 950 Degree-Sign C. Black-Right-Pointing-Pointer CoGe{sub 1.5}Te{sub 1.5} undergoes an order-disorder phase transition at 610 Degree-Sign C. Black-Right-Pointing-Pointer Below 610 Degree-Sign C, anions are arranged trans to each other within Ge{sub 2}Te{sub 2} rings. Black-Right-Pointing-Pointer Above 610 Degree-Sign C, anions are statistically distributed within the Ge{sub 2}Te{sub 2} rings. Black-Right-Pointing-Pointer The effect of the phase transition on the thermal conductivity is discussed.

  3. Two-particle Bose–Einstein correlations in pp collisions at √s=0.9 and 7 TeV measured with the ATLAS detector

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

    Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; et al

    2015-10-01

    The paper presents studies of Bose–Einstein Correlations (BEC) for pairs of like-sign charged particles measured in the kinematic range pT> 100 MeV and |η|< 2.5 in proton collisions at centre-of-mass energies of 0.9 and 7 TeV with the ATLAS detector at the CERN Large Hadron Collider. The integrated luminosities are approximately 7 μb-1, 190 μb-1 and 12.4 nb-1 for 0.9 TeV, 7 TeV minimum-bias and 7 TeV high-multiplicity data samples, respectively. The multiplicity dependence of the BEC parameters characterizing the correlation strength and the correlation source size are investigated for charged-particle multiplicities of up to 240. A saturation effect inmore » the multiplicity dependence of the correlation source size parameter is observed using the high-multiplicity 7 TeV data sample. In conclusion, the dependence of the BEC parameters on the average transverse momentum of the particle pair is also investigated.« less

  4. Ferromagnetism of magnetically doped topological insulators in Cr{sub x}Bi{sub 2−x}Te{sub 3} thin films

    SciTech Connect (OSTI)

    Ni, Y.; Zhang, Z. Hadimani, R. L.; Tuttle, G.; Jiles, D. C.; Nlebedim, I. C.

    2015-05-07

    We investigated the effect of magnetic doping on magnetic and transport properties of Bi{sub 2}Te{sub 3} thin films. Cr{sub x}Bi{sub 2−x}Te{sub 3} thin films with x = 0.03, 0.14, and 0.29 were grown epitaxially on mica substrate with low surface roughness (∼0.4 nm). It is found that Cr is an electron acceptor in Bi{sub 2}Te{sub 3} and increases the magnetization of Cr{sub x}Bi{sub 2−x}Te{sub 3}. When x = 0.14 and 0.29, ferromagnetism appears in Cr{sub x}Bi{sub 2−x}Te{sub 3} thin films, where anomalous Hall effect and weak localization of magnetoconductance were observed. The Curie temperature, coercivity, and remnant Hall resistance of thin films increase with increasing Cr concentration. The Arrott-Noakes plot demonstrates that the critical mechanism of the ferromagnetism can be described better with 3D-Heisenberg model than with mean field model. Our work may benefit for the practical applications of magnetic topological insulators in spintronics and magnetoelectric devices.

  5. Femtosecond laser-induced crystallization of amorphous Sb{sub 2}Te{sub 3} film and coherent phonon spectroscopy characterization and optical injection of electron spins

    SciTech Connect (OSTI)

    Li Simian; Huang Huan; Wang Yang; Wu Yiqun; Gan Fuxi; Zhu Weiling; Wang Wenfang; Chen Ke; Yao Daoxin; Lai Tianshu

    2011-09-01

    A femtosecond laser-irradiated crystallizing technique is tried to convert amorphous Sb{sub 2}Te{sub 3} film into crystalline film. Sensitive coherent phonon spectroscopy (CPS) is used to monitor the crystallization of amorphous Sb{sub 2}Te{sub 3} film at the original irradiation site. The CPS reveals that the vibration strength of two phonon modes that correspond to the characteristic phonon modes (A{sub 1g}{sup 1} and E{sub g}) of crystalline Sb{sub 2}Te{sub 3} enhances with increasing laser irradiation fluence (LIF), showing the rise of the degree of crystallization with LIF and that femtosecond laser irradiation is a good post-treatment technique. Time-resolved circularly polarized pump-probe spectroscopy is used to investigate electron spin relaxation dynamics of the laser-induced crystallized Sb{sub 2}Te{sub 3} film. Spin relaxation process indeed is observed, confirming the theoretical predictions on the validity of spin-dependent optical transition selection rule and the feasibility of transient spin-grating-based optical detection scheme of spin-plasmon collective modes in Sb{sub 2}Te{sub 3}-like topological insulators.

  6. Crystal structure, electronic structure and physical properties of the new low-valent thallium silicon telluride Tl{sub 6}Si{sub 2}Te{sub 6} in comparison to Tl{sub 6}Ge{sub 2}Te{sub 6}

    SciTech Connect (OSTI)

    Assoud, Abdeljalil [Department of Chemistry, University of Waterloo, Waterloo, Ont., N2L 3G1 (Canada); Soheilnia, Navid [Department of Chemistry, University of Waterloo, Waterloo, Ont., N2L 3G1 (Canada); Kleinke, Holger [Department of Chemistry, University of Waterloo, Waterloo, Ont., N2L 3G1 (Canada)]. E-mail: kleinke@uwaterloo.ca

    2006-08-15

    The title compounds were prepared from the elements in the stoichiometric ratio at 800deg. C under exclusion of air. Tl{sub 6}Si{sub 2}Te{sub 6} crystallizes in the space group P1-bar , isostructural with Tl{sub 6}Ge{sub 2}Te{sub 6}, with a=9.4235(6)A, b=9.6606(7)A, c=10.3889(7)A, {alpha}=89.158(2){sup o}, {beta}=96.544(2){sup o}, {gamma}=100.685(2){sup o}, V=923.3(1)A{sup 3} (Z=2). Its structure is composed of dimeric [Si{sub 2}Te{sub 6}]{sup 6-} units with a Si-Si single bond, while the Tl atoms are irregularly coordinated by five to six Te atoms. Numerous weakly bonding Tl-Tl contacts exist. Both title compounds are black semiconductors with small band gaps, calculated to be 0.9eV for Tl{sub 6}Si{sub 2}Te{sub 6} and 0.5eV for Tl{sub 6}Ge{sub 2}Te{sub 6}. The Seebeck coefficients are +65{mu}VK{sup -1} in case of Tl{sub 6}Si{sub 2}Te{sub 6} and +150{mu}VK{sup -1} in case of Tl{sub 6}Ge{sub 2}Te{sub 6} at 300K, and the electrical conductivities are 5.5 and 3{omega}{sup -1}cm{sup -1}, respectively.

  7. Capacitance and conductance characterization of nano-ZnGa{sub 2}Te{sub 4}/n-Si diode

    SciTech Connect (OSTI)

    Fouad, S.S.; Sakr, G.B.; Yahia, I.S.; Abdel-Basset, D.M.; Yakuphanoglu, F.

    2014-01-01

    Graphical abstract: - Highlights: XRD and DTA micrographs were used to study the structure of ZnGa{sub 2}Te{sub 4}. CV, GV and R{sub s}V of the diode characteristics have been analyzed for the first time. Dielectric constant, dielectric loss, loss tangent and ac conductivity were determined. The interfaces states were determined using conductancevoltage technique. ZnGa{sub 2}Te{sub 4} is a good candidate for electronic device applications. - Abstract: Capacitancevoltage (CV) and conductancevoltage (GV) characteristics of p-ZnGa{sub 2}Te{sub 4}/n-Si HJD were studied over a wide frequency and temperature. Both the interface states density N{sub ss} and series resistance R{sub s} were strongly frequency and temperature dependent. The interface states density N{sub ss} is decreased with increasing frequency and increase with increasing temperature. The values of the built-in potential (V{sub bi}) were calculated and found to increase with increasing temperature and frequency. The values of capacitance C, conductance G, series resistance R{sub s}, corrected capacitance C{sub ADJ}, corrected conductance G{sub ADJ}, dielectric constant (??), dielectric loss (??), loss tangent (tan ?) and the AC conductivity (?{sub ac}) are strongly dependent on the applied frequency, voltage and temperature. The obtained results show that the locations of N{sub ss} and R{sub s} have a significant effect on the electrical characteristics of the studied diode.

  8. High-Efficiency CdTe and CIGS Thin-Film Solar Cells: Highlights and Challenges; Preprint

    SciTech Connect (OSTI)

    Noufi, R.; Zweibel, K.

    2006-05-01

    Thin-film photovoltaic (PV) modules of CdTe and Cu(In,Ga)Se2 (CIGS) have the potential to reach cost-effective PV-generated electricity. These technologies have transitioned from the laboratory to the market place. Pilot production and first-time manufacturing are ramping up to higher capacity and enjoying a flood of venture-capital funding. CIGS solar cells and modules have achieved 19.5% and 13% efficiencies, respectively. Likewise, CdTe cells and modules have reached 16.5% and 10.2% efficiencies, respectively. Even higher efficiencies from the laboratory and from the manufacturing line are only a matter of time. Manufacturing-line yield continues to improve and is surpassing 85%. Long-term stability has been demonstrated for both technologies; however, some failures in the field have also been observed, emphasizing the critical need for understanding degradation mechanisms and packaging options. The long-term potential of the two technologies require R&D emphasis on science and engineering-based challenges to find solutions to achieve targeted cost-effective module performance, and in-field durability. Some of the challenges are common to both, e.g., in-situ process control and diagnostics, thinner absorber, understanding degradation mechanisms, protection from water vapor, and innovation in high-speed processing and module design. Other topics are specific to the technology, such as lower-cost and fast-deposition processes for CIGS, and improved back contact and voltage for CdTe devices.

  9. Double Higgs boson production via WW fusion in TeV e sup + e sup minus collisions

    SciTech Connect (OSTI)

    Barger, V.; Han, T. . Dept. of Physics)

    1990-04-10

    The production of two standard model Higgs bosons via the WW fusion process e{sup +}e{sup {minus}} {r arrow} {bar v}{sub e}v{sub e}HH would test the predicted HHH, HWW and HHWW couplings. At TeV energies this fusion cross section dominates over that from e{sup +}e{sup {minus}} {r arrow} ZHH and would give significant event rates for M{sub H}{approx lt} 1/2 M{sub z} at high luminosity e{sup +}e{sup {minus}} colliders. The authors evaluate the rates and present the dynamical distributions.

  10. Defect study in molecular beam epitaxy-grown HgCdTe films with activated and unactivated arsenic

    SciTech Connect (OSTI)

    Izhnin, I. I.; Dvoretsky, S. A.; Mikhailov, N. N.; Varavin, V. S.; Mynbaev, K. D.; Fitsych, O. I.; Pociask-Bialy, M.; Sheregii, E.; Voitsekhovskii, A. V.

    2014-04-28

    A defect study was performed on molecular beam epitaxy-grown HgCdTe films in situ doped with arsenic. Doping was performed from either effusion cell or cracker cell, and studied were both as-grown samples and samples subjected to arsenic activation annealing. Electrical properties of the films were investigated with the use of ion milling as a means of stirring defects in the material. As a result of the study, it was confirmed that the most efficient incorporation of electrically active arsenic occurs at the cracking zone temperature of 700?C. Interaction between arsenic and tellurium during the growth was observed and is discussed in the paper.

  11. Mechanisms of charge transport in anisotype n-TiO{sub 2}/p-CdTe heterojunctions

    SciTech Connect (OSTI)

    Brus, V. V.; Ilashchuk, M. I.; Kovalyuk, Z. D.; Maryanchuk, P. D.; Ulyanytsky, K. S.; Gritsyuk, B. N.

    2011-08-15

    Surface-barrier anisotype n-TiO{sub 2}/p-CdTe heterojunctions are fabricated by depositing thin titanium-dioxide films on a freshly cleaved surface of single-crystalline cadmium-telluride wafers by reactive magnetron sputtering. It is established that the electric current through the heterojunctions under investigation is formed by generation-recombination processes in the space-charge region via a deep energy level and tunneling through the potential barrier. The depth and nature of the impurity centers involved in the charge transport are determined.

  12. Measurement of the Inclusive Jet Cross Section in pp Collisions at √s=7 TeV

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

    Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; et al

    2011-09-19

    The inclusive jet cross section is measured in pp collisions with a center-of-mass energy of 7 TeV at the Large Hadron Collider using the CMS experiment. The data sample corresponds to an integrated luminosity of 34 pb⁻¹. The measurement is made for jet transverse momenta in the range 18–1100 GeV and for absolute values of rapidity less than 3. The measured cross section extends to the highest values of jet pT ever observed and, within the experimental and theoretical uncertainties, is generally in agreement with next-to-leading-order perturbative QCD predictions.

  13. Model independent search for new phenomena in pp̄ collisions at√s=1.96 TeV

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

    Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D; Alkhazov, Georgiy D; Alton, Andrew K; Alverson, George O; Alves, Gilvan Augusto; et al

    2012-05-24

    We describe a model independent search for physics beyond the standard model in lepton final states. We examine 117 final states using 1.1 fb-1 of pp̄ collisions data at √s = 1.96 TeV collected with the D0 detector. We conclude that all observed discrepancies between data and model can be attributed to uncertainties in the standard model background modeling, and hence we do not see any evidence for physics beyond the standard model.

  14. Influence of the thickness of a crystal on the electrical characteristics of Cd(Zn)Te detectors

    SciTech Connect (OSTI)

    Sklyarchuk, V.; Fochuk, p.; Rarenko, I.; Zakharuk, Z.; Sklyarchuk, O. F.; Bolotnikov, A. E.; James, R. B.

    2015-08-01

    We studied the electrical characteristics of Cd(Zn)Te detectors with rectifying contacts and varying thicknesses, and established that their geometrical dimensions affect the measured electrical properties. We found that the maximum value of the operating-bias voltage and the electric field in the detector for acceptable values of the dark current can be achieved when the crystal has an optimum thickness. This finding is due to the combined effect of generation-recombination in the space-charge region and space-charge limited currents (SCLC).

  15. Measurement of the Proton-Air Cross Section at ?s=57 TeV with the Pierre Auger Observatory

    SciTech Connect (OSTI)

    Abreu, P.; Aglietta, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Almeda, A.; Alvarez Castillo, J.; Alvarez-Muiz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Anti?i?, T.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Bcker, T.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Buml, J.; Beatty, J. J.; Becker, B. R.; Becker, K. H.; Belltoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blmer, H.; Boh?ov, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Burton, R. E.; Caballero-Mora, K. S.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chirinos Diaz, J.; Chudoba, J.; Clay, R. W.; Coluccia, M. R.; Conceio, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; De Donato, C.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; Decerprit, G.; del Peral, L.; del Ro, M.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Daz Castro, M. L.; Diep, P. N.; Dobrigkeit, C.; Docters, W.; DOlivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; DUrso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Fajardo Tapia, I.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Ferrero, A.; Fick, B.; Filevich, A.; Filip?i?, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Frhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; Garca, B.; Garcia-Gamez, D.; Garcia-Pinto, D.; Gascon, A.; Gemmeke, H.; Gesterling, K.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gmez Berisso, M.; Gonalves, P.; Gonzalez, D.; Gonzalez, J. G.; Gookin, B.; Gra, D.; Gorgi, A.; Gouffon, P.; Gozzini, S. R.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Guzman, A.; Hague, J. D.; Hansen, P.; Harari, D.; Harmsma, S.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hrandel, J. R.; Horneffer, A.; Horvath, P.; Hrabovsk, M.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jarne, C.; Jiraskova, S.; Josebachuili, M.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Kgl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D.-H.; Kotera, K.; Krohm, N.; Krmer, O.; Kruppke-Hansen, D.; Kuehn, F.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; Lauer, R.; Lautridou, P.; Le Coz, S.; Leo, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Lemiere, A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lpez, R.; Lopez Agera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martnez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Mi?anovi?, S.; Micheletti, M. I.; Miller, W.; Miramonti, L.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Morris, C.; Mostaf, M.; Moura, C. A.; Mueller, S.; Muller, M. A.; Mller, G.; Mnchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Noka, L.; Nyklicek, M.; Oehlschlger, J.; Olinto, A.; Olmos-Gilbaja, V. M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Parsons, R. D.; Pastor, S.; Paul, T.; Pech, M.; P?kala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrinca, P.; Petrolini, A.; Petrov, Y.; Petrovic, J.; Pfendner, C.; Phan, N.

    2012-08-10

    We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [50522(stat)+28-36(syst)] mb is found.

  16. ORISE "AK RlDGE lNSTlT"TE FOR SCIENCE AND EDUCATION

    Office of Legacy Management (LM)

    t\i,;;; il.,. (' . d ORISE "AK RlDGE lNSTlT"TE FOR SCIENCE AND EDUCATION August 1,200l Robert Atkin U.S. Department of Energy Oak Ridge Operations Office P.O. Box 2001 Oak Ridge, TN 3783 1 SUBJECT: CONTRACT NO. DE-AC05000R22750 FINAL REPORT-VERIFICATION SURVEY OF THE NEW BRUNSWICK LABORATORY SITE, NEW BRUNSWICK, NEW JERSEY Dear Mr. Atkin: The Environmental Survey and Site Assessment Program (ESSAP) of the Oak Ridge Institute for Science and Education (ORISE) conducted verification

  17. Molecular beam epitaxial growth of Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} topological insulators on GaAs (111) substrates: a potential route to fabricate topological insulator p-n junction

    SciTech Connect (OSTI)

    Zeng, Zhaoquan; Morgan, Timothy A.; Li, Chen; Hirono, Yusuke; Hu, Xian; Hawkridge, Michael E.; Benamara, Mourad; Salamo, Gregory J.; Fan, Dongsheng; Yu, Shuiqing; Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701 ; Zhao, Yanfei; Lee, Joon Sue; Wang, Jian; The Center for Nanoscale Science and Department of Physics, The Pennsylvania State University, University Park, PA 16802 ; Wang, Zhiming M.; State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054; Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Science, Beijing 100083

    2013-07-15

    High quality Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} topological insulators films were epitaxially grown on GaAs (111) substrate using solid source molecular beam epitaxy. Their growth and behavior on both vicinal and non-vicinal GaAs (111) substrates were investigated by reflection high-energy electron diffraction, atomic force microscopy, X-ray diffraction, and high resolution transmission electron microscopy. It is found that non-vicinal GaAs (111) substrate is better than a vicinal substrate to provide high quality Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} films. Hall and magnetoresistance measurements indicate that p type Sb{sub 2}Te{sub 3} and n type Bi{sub 2}Te{sub 3} topological insulator films can be directly grown on a GaAs (111) substrate, which may pave a way to fabricate topological insulator p-n junction on the same substrate, compatible with the fabrication process of present semiconductor optoelectronic devices.

  18. A=3Li (2010PU04)

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

    1987TI07) identified reactions 1 through 4 below as possible candidates for the observation of a bound or resonant state of three protons. An additional possibility would be...

  19. NR Pu SEIS Advisory 07272012_Clean

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

    ( 423) 7 51---8400 Valley A uthority: r rgolden@tva.gov DOE A nnounces I ssuance o f D raft S upplemental E nvironmental S tudy o n P lutonium D isposition WASHINGTON, D C - T...

  20. Energy dependence of fission product yields from 235U, 238U and 239Pu for incident neutron energies between 0.5 and 14.8 MeV

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

    Gooden, M. E.; Arnold, C. W.; Becker, J. A.; Bhatia, C.; Bhike, M.; Bond, E. M.; Bredeweg, T. A.; Fallin, B.; Fowler, M. M.; Howell, C. R.; et al

    2016-01-06

    In this study, Fission Product Yields (FPY) have historically been one of the most observable features of the fission process. They are known to have strong variations that are dependent on the fissioning species, the excitation energy, and the angular momentum of the compound system. However, consistent and systematic studies of the variation of these FPY with energy have proved challenging. This is caused primarily by the nature of the experiments that have traditionally relied on radiochemical procedures to isolate specific fission products. Although radiochemical procedures exist that can isolate all products, each element presents specific challenges and introduces varyingmore » degrees of systematic errors that can make inter-comparison of FPY uncertain. Although of high importance in fields such as nuclear forensics and Stockpile Stewardship, accurate information about the energy dependence of neutron induced FPY are sparse, due primarily to the lack of suitable monoenergetic neutron sources. There is a clear need for improved data, and to address this issue, a collaboration was formed between Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL) and the Triangle Universities Nuclear Laboratory (TUNL) to measure the energy dependence of FPY for 235U, 238U and 239Pu. The measurements have been performed at TUNL, using a 10 MV Tandem Van de Graaff accelerator to produce monoenergetic neutrons at energies between 0.6 MeV to 14.8 MeV through a variety of reactions. The measurements have utilized a dual-fission chamber, with thin (10-100 μg/cm2) reference foils of similar material to a thick (100-400 mg) activation target held in the center between the chambers. This method allows for the accurate determination of the number of fissions that occurred in the thick target without requiring knowledge of the fission cross section or neutron fluence on target. Following activation, the thick target was removed from the dual-fission chamber and gamma-ray counted using shielded HPGe detectors for a period of 1-2 months to determine the yield of various fission products. To the extent possible all irradiation and counting procedures were kept the same to minimize sources of systematic errors. FPY have been determined at incident neutron energies of 0.6, 1.4, 2.4, 3.5, 4.6, 5.5, 8.9 and 14.8 MeV.« less

  1. Novel signal inversion of laser beam induced current for femtosecond-laser-drilling-induced junction on vacancy-doped p-type HgCdTe

    SciTech Connect (OSTI)

    Qiu, W. C.; Wang, R.; Xu, Z. J.; Jiang, T.; Cheng, X. A.

    2014-05-28

    In this paper, experimental results of temperature-dependent signal inversion of laser beam induced current (LBIC) for femtosecond-laser-drilling-induced junction on vacancy-doped p-type HgCdTe are reported. LBIC characterization shows that the traps induced by femtosecond laser drilling are sensitive to temperature. Theoretical models for trap-related p-n junction transformation are proposed and demonstrated using numerical simulations. The simulations are in good agreement with the experimental results. The effects of traps and mixed conduction are possibly the main reasons that result in the novel signal inversion of LBIC microscope at room temperature. The research results provide a theoretical guide for practical applications of large-scale array HgCdTe infrared photovoltaic detectors formed by femtosecond laser drilling, which may act as a potential new method for fabricating HgCdTe photodiodes.

  2. Atomic arrangement at ZnTe/CdSe interfaces determined by high resolution scanning transmission electron microscopy and atom probe tomography

    SciTech Connect (OSTI)

    Bonef, Bastien; Rouvire, Jean-Luc; Jouneau, Pierre-Henri; Bellet-Amalric, Edith; Grard, Lionel; Mariette, Henri; Andr, Rgis; Bougerol, Catherine; Grenier, Adeline

    2015-02-02

    High resolution scanning transmission electron microscopy and atom probe tomography experiments reveal the presence of an intermediate layer at the interface between two binary compounds with no common atom, namely, ZnTe and CdSe for samples grown by Molecular Beam Epitaxy under standard conditions. This thin transition layer, of the order of 1 to 3 atomic planes, contains typically one monolayer of ZnSe. Even if it occurs at each interface, the direct interface, i.e., ZnTe on CdSe, is sharper than the reverse one, where the ZnSe layer is likely surrounded by alloyed layers. On the other hand, a CdTe-like interface was never observed. This interface knowledge is crucial to properly design superlattices for optoelectronic applications and to master band-gap engineering.

  3. Search for strong gravity in multijet final states produced in pp collisions at √s = 13 TeV using the ATLAS detector at the LHC

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

    Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Aben, R.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; et al

    2016-03-07

    A search is conducted for new physics in multijet final states using 3.6 inverse femtobarns of data from proton-proton collisions at √s = 13 TeV taken at the CERN Large Hadron Collider with the ATLAS detector. Events are selected containing at least three jets with scalar sum of jet transverse momenta (HT) greater than 1 TeV. No excess is seen at large HT and limits are presented on new physics: models which produce final states containing at least three jets and having cross sections larger than 1.6 fb with HT > 5.8 TeV are excluded. As a result, limits aremore » also given in terms of new physics models of strong gravity that hypothesize additional space-time dimensions.« less

  4. Search for contact interactions in dimuon events from pp collisions at √s=7 TeV with the ATLAS detector

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

    Aad, G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; Abramowicz, H.; Abreu, H.; et al

    2011-07-01

    A search for contact interactions has been performed using dimuon events recorded with the ATLAS detector in proton-proton collisions at √s=7 TeV. The data sample corresponds to an integrated luminosity of 42 pb⁻¹. No significant deviation from the standard model is observed in the dimuon mass spectrum, allowing the following 95% C.L. limits to be set on the energy scale of contact interactions: Λ>4.9 TeV (4.5 TeV) for constructive (destructive) interference in the left-left isoscalar compositeness model. These limits are the most stringent to date for μμqq contact interactions.

  5. ATLAS search for a heavy gauge boson decaying to a charged lepton and a neutrino in pp collisions at √s = 7 TeV

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

    Aad, G.

    2012-12-08

    The ATLAS detector at the LHC is used to search for high-mass states, such as heavy charged gauge bosons (W'), decaying to a charged lepton (electron or muon) and a neutrino. Results are presented based on the analysis of pp collisions at a centre-of-mass energy of 7 TeV corresponding to an integrated luminosity of 4.7 fb-1. No excess beyond Standard Model expectations is observed. A W' with Sequential Standard Model couplings is excluded at the 95% credibility level for masses up to 2.55 TeV. Excited chiral bosons (W*) with equivalent coupling strength are excluded for masses up to 2.42 TeV.

  6. Role of polycrystallinity in CdTe and CuInSe{sub 2} photovoltaic cells. Annual subcontract report, 1 April 1990--31 March 1991

    SciTech Connect (OSTI)

    Sites, J.R.

    1991-12-31

    The polycrystalline nature of thin-film CdTe and CuInSe{sub 2} solar cells continues to be a major factor in several individual losses that limit overall cell efficiency. This report describes progress in the quantitative separation of these losses, including both measurement and analysis procedures. It also applies these techniques to several individual cells to help document the overall progress with CdTe and CuInSe{sub 2} cells. Notably, CdTe cells from Photon Energy have reduced window photocurrent losses to 1 mA/Cm{sup 2}; those from the University of South Florida have achieved a maximum power voltage of 693 mV; and CuInSe{sub 2} cells from International Solar Electric Technology have shown a hole density as high as 7 {times} 10{sup 16} cm{sup {minus}3}, implying a significant reduction in compensation. 9 refs.

  7. Search for W' decaying to tau lepton and neutrino in proton-proton collisions at $\\sqrt{s}$ = 8 TeV

    SciTech Connect (OSTI)

    Khachatryan, Vardan

    2015-08-19

    We found that the first search for a heavy charged vector boson in the final state with a tau lepton and a neutrino is reported, using 19.7 fb-1 of LHC data at ?s = 8 TeV. A signal would appear as an excess of events in kinematic regions where the standard model background is low. No excess is observed. Limits are set on a model in which the W' decays preferentially to fermions of the third generation. Our results substantially extend previous constraints on this model. Masses below 2.0 to 2.7 TeV are excluded, depending on the model parameters. In addition, the existence of a W' boson with universal fermion couplings is excluded at 95% confidence level, for W' masses below 2.7 TeV.

  8. Search for Z' resonances decaying to tt¯; in dilepton+jets final states in pp collisions at √s=7 TeV

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

    Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Aguilo, E.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; et al

    2013-04-03

    A search for resonances decaying to top quark-antiquark pairs is performed using a dilepton+jets data sample recorded by the CMS experiment at the LHC in pp collisions at √s=7 TeV corresponding to an integrated luminosity of 5.0 b⁻¹. No significant deviations from the standard model background are observed. Upper limits are presented for the production cross section times branching fraction of top quark-antiquark resonances for masses from 750 to 3000 GeV. In particular, the existence of a leptophobic topcolor particle Z' is excluded at the 95% confidence level for resonance masses MZ'<1.3 TeV for ΓZ'=0.012MZ', and M<1.9 TeV for ΓZ'=0.10MZ'.

  9. Search for massive resonances in dijet systems containing jets tagged as W or Z boson decays in pp collisions at ?s = 8 TeV

    SciTech Connect (OSTI)

    Khachatryan, Vardan

    2014-08-01

    Search for massive resonances in dijet systems containing jets tagged as W or Z boson decays in pp collisions at ?s = 8 TeV05/08/2014A search is reported for massive resonances decaying into a quark and a vector boson (W or Z), or two vector bosons (WW, WZ, or ZZ). The analysis is performed on an inclusive sample of multijet events corresponding to an integrated luminosity of 19.7 inverse femtobarns, collected in proton-proton collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC. The search uses novel jet-substructure identification techniques that provide sensitivity to the presence of highly boosted vector bosons decaying into a pair of quarks. Exclusion limits are set at a confidence level of 95% on the production of: (i) excited quark resonances q* decaying to qW and qZ for masses less than 3.2 TeV and 2.9 TeV, respectively, (ii) a Randall-Sundrum graviton G[RS] decaying into WW for masses below 1.2 TeV, and (iii) a heavy partner of the W boson W' decaying into WZ for masses less than 1.7 TeV. For the first time mass limits are set on W' to WZ and G[RS] to WW in the all-jets final state. The mass limits on q* to qW, q* to qZ, W' to WZ, G[RS] to WW are the most stringent to date. A model with a "bulk" graviton G[Bulk] that decays into WW or ZZ bosons is also studied.

  10. Nano-crystalline p-ZnGa{sub 2}Te{sub 4}/n-Si as a new heterojunction diode

    SciTech Connect (OSTI)

    Sakr, G.B.; Fouad, S.S.; Yahia, I.S.; Abdel Basset, D.M.; Yakuphanoglu, F.

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ? ZnGa{sub 2}Te{sub 4}/Si thin film was prepared by thermal evaporation technique. ? XRD and AFM graphs support the nano-crystalline of the studied device. ? Dark currentvoltage characteristics of the heterojunction diode were investigated. ? Electrical parameters and conduction mechanism were determined. ? Conduction mechanisms were controlled by TE, SCLC and TCLC. -- Abstract: In this communication, ZnGa{sub 2}Te{sub 4} thin film was prepared by thermal evaporation technique on n-Si substrate. P-ZnGa{sub 2}Te{sub 4}/n-Si heterojunction diode was fabricated. The structure of ZnGa{sub 2}Te{sub 4} thin film was checked by XRD pattern and confirmed by AFM micrographs. The dark currentvoltage characteristics of the heterojunction diode were investigated to determine the electrical parameters and conduction mechanism as a function of forward and reverse biasing conditions in the range (?10 V to 10 V) at temperature interval (303423 K). The conduction mechanism was controlled by thermionic emission, space charge limited (SCLC) and trap-charge limited current (TCLC) mechanisms. The basic parameters such as the series resistance R{sub s}, the shunt resistance R{sub sh}, the ideality factor n and the barrier height ?{sub b} of the diode, the total density of trap states N{sub 0} and the exponential trapping distribution P{sub o} were determined. The obtained results showed that ZnGa{sub 2}Te{sub 4} is a good candidate for the applications of electronic devices.

  11. OM-300 - MWD Geothermal Navigation Instrument Geothermal Project...

    Open Energy Info (EERE)

    Principal Investigators Bruce Ohme, Principal Engineer, Honeywell International; Bill Goodman, President, Applied Physics Systems (APS) Targets Milestones A Directional and...

  12. OM300-GeoThermal MWD Navigation Instrument

    Broader source: Energy.gov [DOE]

    Develop a 300°C capable directional drilling navigation tool using Micro Electro-Mechanical Systems (MEMS) accelerometers and flux-gate magnetometers.

  13. Microsoft Word - S08406_MND_OM_Plan.docx

    Office of Legacy Management (LM)

    ... for conducting and approving CERCLA activities at the site. 1991: The Nuclear Weapons Complex Reconfiguration Study recommended closure of many DOE sites and ...

  14. Microsoft Word - S08406_MND_OM_Plan.docx

    Office of Legacy Management (LM)

    Sample Inspection Checklist Questions and Mound Site Landowners - Institutional Controls Compliance Form This page intentionally left blank U.S. Department of Energy Operations and Maintenance Plan for the U.S. DOE Mound Site January 2015 Doc. No. S08406-1.0 Page A-1 The following is an example checklist of items covered by the annual IC assessment. Scope: IC Compliance for the Mound, Ohio, Site Preliminary inspections performed on: <dates> Physical inspection walkdown with regulators on:

  15. MODELING PHOTODISINTEGRATION-INDUCED TeV PHOTON EMISSION FROM LOW-LUMINOSITY GAMMA-RAY BURSTS

    SciTech Connect (OSTI)

    Liu Xuewen [Physics Department, Sichuan University, Chengdu 610065 (China); Wu Xuefeng; Lu Tan, E-mail: astrolxw@gmail.com, E-mail: xfwu@pmo.ac.cn, E-mail: t.lu@pmo.ac.cn [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2012-05-15

    Ultra-high-energy cosmic-ray heavy nuclei have recently been considered as originating from nearby low-luminosity gamma-ray bursts that are associated with Type Ibc supernovae. Unlike the power-law decay in long duration gamma-ray bursts, the light curve of these bursts exhibits complex UV/optical behavior: shock breakout dominated thermal radiation peaks at about 1 day, and, after that, nearly constant emission sustained by radioactive materials for tens of days. We show that the highly boosted heavy nuclei at PeV energy interacting with the UV/optical photon field will produce considerable TeV photons via the photodisintegration/photo-de-excitation process. It was later predicted that a thermal-like {gamma}-ray spectrum peaks at about a few TeV, which may serve as evidence of nucleus acceleration. The future observations by the space telescope Fermi and by the ground atmospheric Cherenkov telescopes such as H.E.S.S., VERITAS, and MAGIC will shed light on this prediction.

  16. Prospects for GeV-TeV detection of short gamma-ray bursts with extended emission

    SciTech Connect (OSTI)

    Veres, P.; Mszros, P., E-mail: veres@gwu.edu [Department of Astronomy and Astrophysics Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

    2014-06-01

    We discuss the GeV to TeV photon emission of gamma-ray bursts (GRBs) within the refreshed shock and the continuous injection scenarios, motivated by the observation of extended emission in a substantial fraction of short GRBs. In the first model we assume that the central engine promptly emits material with a range of Lorentz factors. When the fastest shell starts to decelerate, it drives a forward shock into the ambient medium and a reverse shock into the ejecta. These shocks are reenergized by the slower and later arriving material. In the second model we assume that there is a continued ejection of material over an extended time, and the continuously arriving new material keeps reenergizing the shocks formed by the preceding shells of ejecta. We calculate the synchrotron and synchrotron self-Compton radiation components for the forward and reverse shocks and find that prospective and current GeV-TeV range instruments such as CTA, HAWC, VERITAS, MAGIC, and HESS have a good chance of detecting afterglows of short bursts with extended emission, assuming a reasonable response time.

  17. Magnetoinfrared spectroscopy of Landau levels and Zeeman splitting of three-dimensional massless Dirac Fermions in ZrTe5

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

    R. Y. Chen; Gu, G. D.; Chen, Z. G.; Song, X. -Y.; Schneeloch, J. A.; Wang, F.; Wang, N. L.

    2015-10-22

    We present a magnetoinfrared spectroscopy study on a newly identified three-dimensional (3D) Dirac semimetal ZrTe5. We observe clear transitions between Landau levels and their further splitting under a magnetic field. Both the sequence of transitions and their field dependence follow quantitatively the relation expected for 3D massless Dirac fermions. The measurement also reveals an exceptionally low magnetic field needed to drive the compound into its quantum limit, demonstrating that ZrTe5 is an extremely clean system and ideal platform for studying 3D Dirac fermions. The splitting of the Landau levels provides direct, bulk spectroscopic evidence that a relatively weak magnetic fieldmore » can produce a sizable Zeeman effect on the 3D Dirac fermions, which lifts the spin degeneracy of Landau levels. As a result, our analysis indicates that the compound evolves from a Dirac semimetal into a topological line-node semimetal under the current magnetic field configuration.« less

  18. Modeling of 10 GeV-1 TeV laser-plasma accelerators using Lorentz booster simulations

    SciTech Connect (OSTI)

    Vay, J.-L.; Geddes, C.G.R.; Esarey, E.; Esarey, E.; Leemans, W.P.; Cormier-Michel, E.; Grote, D.P.

    2011-12-01

    Modeling of laser-plasma wakefield accelerators in an optimal frame of reference [J.-L. Vay, Phys. Rev. Lett. 98 130405 (2007)] allows direct and e#14;fficient full-scale modeling of deeply depleted and beam loaded laser-plasma stages of 10 GeV-1 TeV (parameters not computationally accessible otherwise). This verifies the scaling of plasma accelerators to very high energies and accurately models the laser evolution and the accelerated electron beam transverse dynamics and energy spread. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively. Agreement at the percentage level is demonstrated between simulations using different frames of reference for a 0.1 GeV class stage. Obtaining these speedups and levels of accuracy was permitted by solutions for handling data input (in particular particle and laser beams injection) and output in a relativistically boosted frame of reference, as well as mitigation of a high-frequency instability that otherwise limits effectiveness.

  19. Magnetic Correlations in the Quasi-Two-Dimensional Semiconducting Ferromagnet CrSiTe3

    SciTech Connect (OSTI)

    Williams, Travis J.; Aczel, Adam A.; Lumsden, Mark D.; Nagler, Stephen E.; Stone, Matthew B.; Yan, Jiaqiang -Q.; Mandrus, D.

    2015-10-02

    Intrinsic, 2D ferromagnetic semiconductors are an important class of materials for overcoming dilute magnetic semiconductors limitations for spintronics. CrSiTe3 is a particularly interesting material of this class, since it can likely be exfoliated to single layers, for which Tc is predicted to increase dramatically. Establishing the nature of the bulk materials magnetism is necessary for understanding the thin-film magnetic behavior and the materials possible applications. In this work, we use elastic and inelastic neutron scattering to measure the magnetic properties of single crystalline CrSiTe3. We find a very small single ion anisotropy that favors magnetic ordering along the c-axis and that the measured spin waves fit well to a model in which the moments are only weakly coupled along that direction. Then, we find that both static and dynamic correlations persist within the ab-plane up to at least 300 K, which is strong evidence of the material's 2D characteristics that are relevant for future studies on thin film and monolayer samples.

  20. High-throughput manufacturing of thin-film CdS/CdTe photovoltaic modules. Annual subcontract report, 16 September 1996--15 January 1998

    SciTech Connect (OSTI)

    Sandwisch, D.W. [Solar Cells, Inc., Toledo, OH (United States)

    1998-08-01

    Cadmium telluride (CdTe) is recognized as one of the leading materials for low-cost photovoltaic modules. Solar Cells, Inc., has developed this technology and is scaling its pilot production capabilities to a multi-megawatt level. The Photovoltaic Manufacturing Technology (PVMaT) subcontract supports these efforts. Activities during the third phase of the program concentrated on process development, equipment design and testing, quality assurance, ES and H programs, and large-scale next-generation coating-system prototype development. These efforts broadly addressed the issues of the manufacturing process for producing thin-film, monolithic CdS/CdTe photovoltaic modules.