Sample records for atmospheric optics sb

  1. Atmospheric optical calibration system

    DOE Patents [OSTI]

    Hulstrom, Roland L. (Bloomfield, CO); Cannon, Theodore W. (Golden, CO)

    1988-01-01T23:59:59.000Z

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions.

  2. Atmospheric optical calibration system

    DOE Patents [OSTI]

    Hulstrom, R.L.; Cannon, T.W.

    1988-10-25T23:59:59.000Z

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions. 7 figs.

  3. InAs/InAsSb strain balanced superlattices for optical detectors: Material properties and energy band simulations

    E-Print Network [OSTI]

    Krishna, Sanjay

    InAs/InAsSb strain balanced superlattices for optical detectors: Material properties and energyAs/InAsSb strain balanced superlattices for optical detectors: Material properties and energy band simulations D February 2012) InAsSb/InAs type II strain balanced superlattices lattice matched to GaSb have recently been

  4. atmospheric optical turbulence: Topics by E-print Network

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

    Next Page Last Page Topic Index 1 Atmospheric Turbulence and its Influence on Adaptive Optics Physics Websites Summary: Atmospheric Turbulence and its Influence on Adaptive Optics...

  5. Optical nonlinear absorption characteristics of Sb{sub 2}Se{sub 3} nanoparticles

    SciTech Connect (OSTI)

    Muralikrishna, Molli, E-mail: muralikrishnamolli@sssihl.edu.in; Kiran, Aditha Sai, E-mail: muralikrishnamolli@sssihl.edu.in; Ravikanth, B., E-mail: muralikrishnamolli@sssihl.edu.in; Sowmendran, P., E-mail: muralikrishnamolli@sssihl.edu.in; Muthukumar, V. Sai, E-mail: muralikrishnamolli@sssihl.edu.in; Venkataramaniah, Kamisetti, E-mail: muralikrishnamolli@sssihl.edu.in [Department of Physics, Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam-515 134 (India)

    2014-04-24T23:59:59.000Z

    In this work, we report for the first time, the nonlinear optical absorption properties of antimony selenide (Sb{sub 2}Se{sub 3}) nanoparticles synthesized through solvothermal route. X-ray diffraction results revealed the crystalline nature of the nanoparticles. Electron microscopy studies revealed that the nanoparticles are in the range of 10 - 40 nm. Elemental analysis was performed using EDAX. By employing open aperture z-scan technique, we have evaluated the effective two-photon absorption coefficient of Sb{sub 2}Se{sub 3} nanoparticles to be 5e-10 m/W at 532 nm. These nanoparticles exhibit strong intensity dependent nonlinear optical absorption and hence could be considered to have optical power limiting applications in the visible range.

  6. Time resolved magneto-optical studies of ferromagnetic InMnSb films

    SciTech Connect (OSTI)

    Frazier, M.; Kini, R. N.; Nontapot, K.; Khodaparast, G. A. [Department of Physics, Virginia Tech, Blacksburg, Virginia 24061 (United States); Wojtowicz, T. [Institute of Physics, Polish Academy of Sciences 02-668 Warsaw (Poland); Liu, X.; Furdyna, J. K. [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

    2008-02-11T23:59:59.000Z

    We report time resolved magneto-optical measurements in InMnSb ferromagnetic films with 2% and 2.8% Mn contents grown by low temperature molecular beam epitaxy. In order to probe a possible interaction between the spins of photoexcited carriers and the Mn ions, we measured spin dynamics before and after aligning the Mn ions by applying an external magnetic field at temperatures above and below the samples' Curie temperatures. We observed no significant temperature or magnetic field dependence in the relaxation times and attribute the observed dynamics entirely to the relaxation of photoexcited electrons in the conduction band where the s-d coupling with the localized Mn ions is significantly weaker compared to the p-d exchange coupling. We observed several differences in the optical response of our InMnSb samples which could have been influenced mainly by the samples' growth conditions.

  7. Structural and optical properties of Sb{sub 2}S{sub 3} nanocrystals in glass

    SciTech Connect (OSTI)

    Mishra, Rakesh K., E-mail: mishrarake@gmail.com; Kashyap, Raman, E-mail: mishrarake@gmail.com; Vedeshwar, A. G., E-mail: mishrarake@gmail.com; Tandon, R. P., E-mail: mishrarake@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi 1-10007 (India)

    2014-04-24T23:59:59.000Z

    In this work conventional solid state precipitation method is adopted to fabricate Sb{sub 2}S{sub 3} nanocrystals in glass. The glass composition is optimized for proper host glass matrix to grow antimony trisulphide semiconductor quantum dots. The dot size is modified by heat treatment of glass samples in the temperature range from 550°C to 700°C for various time durations. Structural studies are carried out by X-ray diffraction and transmission electron microscopy and nanoparticles with size ranges from 8 nm to 70 nm are obtained. Quantum dots so grown were further characterized by optical absorption spectroscopy and a blue shift is observed for absorption edge energy that conform the quantum confinement effect.

  8. METR 3223: Physical Meteorology II: Cloud Physics, Atmospheric Electricity and Optics

    E-Print Network [OSTI]

    Droegemeier, Kelvin K.

    METR 3223: Physical Meteorology II: Cloud Physics, Atmospheric Electricity and Optics CLASS: Monday of the physical states and processes of clouds and precipitation as well as atmospheric electricity and optics Thunderstorm charging Lightening Atmospheric optics: Reflection and refraction Optical phenomena GRADES

  9. METR 3223: Physical Meteorology II: Cloud Physics, Atmospheric Electricity and Optics

    E-Print Network [OSTI]

    Droegemeier, Kelvin K.

    METR 3223: Physical Meteorology II: Cloud Physics, Atmospheric Electricity and Optics CLASS: Monday as atmospheric electricity and optics. Specific topics that will be covered are as follows: Cloud physics: Review Lightening Atmospheric optics: Reflection and refraction Optical phenomena GRADES Homework problems: 20% Quiz

  10. atmospheric optics russian: Topics by E-print Network

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

    atmospheric optics russian First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Performance of synchronous...

  11. Levitating atmospheres of Eddington-luminosity neutron stars I. Optically thin Thomson-scattering atmospheres

    E-Print Network [OSTI]

    Wielgus, M; S?dowski, A; Narayan, R; Abramowicz, M

    2015-01-01T23:59:59.000Z

    In general relativity static gaseous atmospheres may be in hydrostatic balance in the absence of a supporting stellar surface, provided that the luminosity is close to the Eddington value. We construct analytic models of optically thin, spherically symmetric shells supported by the radiation pressure of a luminous central body in the Schwarzschild metric.

  12. Levitating atmospheres of Eddington-luminosity neutron stars I. Optically thin Thomson-scattering atmospheres

    E-Print Network [OSTI]

    M. Wielgus; W. Klu?niak; A. S?dowski; R. Narayan; M. Abramowicz

    2015-05-22T23:59:59.000Z

    In general relativity static gaseous atmospheres may be in hydrostatic balance in the absence of a supporting stellar surface, provided that the luminosity is close to the Eddington value. We construct analytic models of optically thin, spherically symmetric shells supported by the radiation pressure of a luminous central body in the Schwarzschild metric.

  13. Proc. of Atmospheric Studies by Optical Methods (2001) :16 Optical Emissions from Proton Aurora

    E-Print Network [OSTI]

    Lummerzheim, Dirk

    2001-01-01T23:59:59.000Z

    Proc. of Atmospheric Studies by Optical Methods (2001) :1­6 Optical Emissions from Proton Aurora D of proton aurora. The Doppler-shifted hydrogen emission lines can be inter- preted in terms of the mean in electron aurora, the relative brightness of emis- sion features differs from that in electron aurora

  14. Optical remote diagnostics of atmospheric propagating beams of ionizing radiation

    DOE Patents [OSTI]

    Karl, Jr., Robert R. (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    Data is obtained for use in diagnosing the characteristics of a beam of ionizing radiation, such as charged particle beams, neutral particle beams, and gamma ray beams. In one embodiment the beam is emitted through the atmosphere and produces nitrogen fluorescence during passage through air. The nitrogen fluorescence is detected along the beam path to provide an intensity from which various beam characteristics can be calculated from known tabulations. Optical detecting equipment is preferably located orthogonal to the beam path at a distance effective to include the entire beam path in the equipment field of view.

  15. Optical emission spectroscopy of atmospheric pressure microwave plasmas

    SciTech Connect (OSTI)

    Jia Haijun; Fujiwara, Hiroyuki; Kondo, Michio [Research Center for Photovoltaics (RCPVs), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Kuraseko, Hiroshi [Furukawa Electric Co., Ltd., Production Technology Development Center, 6 Yawata-Kaigandori, Chiba 290-8555 (Japan)

    2008-09-01T23:59:59.000Z

    The optical emission behaviors of Ar, He, and Ar+He plasmas generated in air using an atmospheric pressure microwave plasma source have been studied employing optical emission spectroscopy (OES). Emissions from various source gas species and air were observed. The variations in the intensities and intensity ratios of specific emissions as functions of the microwave power and gas flow rate were analyzed to investigate the relationship between the emission behavior and the plasma properties. We find that dependence of the emission behavior on the input microwave power is mainly determined by variations in electron density and electron temperature in the plasmas. On the other hand, under different gas flow rate conditions, changes in the density of the source gas atoms also significantly affect the emissions. Interestingly, when plasma is generated using an Ar+He mixture, emissions from excited He atoms disappear while a strong H{sub {alpha}} signal appears. The physics behind these behaviors is discussed in detail.

  16. Capping layer growth rate and the optical and structural properties of GaAsSbN-capped InAs/GaAs quantum dots

    SciTech Connect (OSTI)

    Ulloa, J. M., E-mail: jmulloa@isom.upm.es; Utrilla, A. D.; Guzman, A.; Hierro, A. [Institute for Systems based on Optoelectronics and Microtechnology (ISOM) and Dpto. Ingeniería Electrónica, Universidad Politecnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Reyes, D. F.; Ben, T.; González, D. [Departamento de Ciencia de los Materiales e IM y QI, Universidad de Cádiz, 11510 Puerto Real (Cádiz) (Spain)

    2014-10-07T23:59:59.000Z

    Changing the growth rate during the heteroepitaxial capping of InAs/GaAs quantum dots (QDs) with a 5?nm-thick GaAsSbN capping layer (CL) strongly modifies the QD structural and optical properties. A size and shape transition from taller pyramids to flatter lens-shaped QDs is observed when the CL growth rate is decreased from 1.5 to 0.5 ML/s. This indicates that the QD dissolution processes taking place during capping can be controlled to some extent by the GaAsSbN CL growth rate, with high growth rates allowing a complete preservation of the QDs. However, the dissolution processes are shown to have a leveling effect on the QD height, giving rise to a narrower size distribution for lower growth rates. Contrary to what could be expected, these effects are opposite to the strong blue-shift and improvement of the photoluminescence (PL) observed for higher growth rates. Nevertheless, the PL results can be understood in terms of the strong impact of the growth rate on the Sb and N incorporation into the CL, which results in lower Sb and N contents at higher growth rates. Besides the QD-CL band offsets and QD strain, the different CL composition alters the band alignment of the system, which can be transformed to type-II at low growth rates. These results show the key role of the alloyed CL growth parameters on the resulting QD properties and demonstrate an intricate correlation between the PL spectra and the sample morphology in complex QD-CL structures.

  17. Retrieval of optical and microphysical properties of ice clouds using Atmospheric Radiation Measurement (ARM) data 

    E-Print Network [OSTI]

    Kinney, Jacqueline Anne

    2005-11-01T23:59:59.000Z

    The research presented here retrieves the cloud optical thickness and particle effective size of cirrus clouds using surface radiation measurements obtained during the Atmospheric Radiation Measurement (ARM) field campaign. The algorithm used...

  18. Optical communication through the turbulent atmosphere with transmitter and receiver diversity, wavefront control, and coherent detection

    E-Print Network [OSTI]

    Puryear, Andrew Lee

    2011-01-01T23:59:59.000Z

    Free space optical communication through the atmosphere has the potential to provide secure, low-cost, rapidly deployable, dynamic, data transmission at very high rates. However, the deleterious effects of turbulence can ...

  19. atmospheric aerosol optical: Topics by E-print Network

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

    Size Distribution Physics (arXiv) Summary: Atmospheric flows exhibit selfsimilar fractal spacetime fluctuations manifested as the fractal geometry to global cloud cover...

  20. Ohmic contacts to n-GaSb

    E-Print Network [OSTI]

    Yang, Zhengchong

    1997-01-01T23:59:59.000Z

    In recent years, the Ill-V semiconductor GaSb and its ternary alloys containing antimony have exhibited interesting electrical and optical properties for device applications which include negative resistance tunnel devices, lasers, detectors and FET...

  1. Modeling of the optical properties of nonspherical particles in the atmosphere

    E-Print Network [OSTI]

    Chen, Guang

    2009-05-15T23:59:59.000Z

    , Richard Orville August 2007 Major Subject: Atmospheric Sciences iii ABSTRACT Modeling of the Optical Properties of Nonspherical Particles in the Atmosphere. (August 2007) Guang Chen, B.S., Jilin University; M.S., University of Southern..., the computation demand also goes up with 8 the increase of the spatial resolution. Alternatively, the pseudo-spectral time-domain (PSTD) method pioneered by Liu [63, 67] in 1997 and 1998 to solve Maxwell?s equations and study propagations of acoustic waves...

  2. Comparison of optical emission from nanosecond and femtosecond laser produced plasma in atmosphere and vacuum conditions

    E-Print Network [OSTI]

    Harilal, S. S.

    occur during the laser pulse in ns laser ablation, fs laser pulses are too short that these phenomena doComparison of optical emission from nanosecond and femtosecond laser produced plasma in atmosphere Laser-induced breakdown spectroscopy Laser-produced plasma Plasma dynamics Femtosecond laser ablation

  3. Precision Determination of Atmospheric Extinction at Optical and Near IR Wavelengths

    SciTech Connect (OSTI)

    Burke, David L.; /SLAC; Axelrod, T.; /Arizona U., Astron. Dept. - Steward Observ.; Blondin, Stephane; /European Southern Observ. /Marseille, CPPM; Claver, Chuck; /NOAO, Tucson; Ivezic, Zeljko; Jones, Lynne; /Washington U., Seattle, Astron. Dept.; Saha, Abhijit; /NOAO, Tucson; Smith, Allyn; /Austin Peay State U.; Smith, R.Chris; /Cerro-Tololo InterAmerican Obs.; Stubbs, Christopher W.; /Harvard-Smithsonian Ctr. Astrophys.

    2011-08-24T23:59:59.000Z

    The science goals for future ground-based all-sky surveys, such as the Dark Energy Survey, PanSTARRS, and the Large Synoptic Survey Telescope, require calibration of broadband photometry that is stable in time and uniform over the sky to precisions of a per cent or better, and absolute calibration of color measurements that are similarly accurate. This performance will need to be achieved with measurements made from multiple images taken over the course of many years, and these surveys will observe in less than ideal conditions. This paper describes a technique to implement a new strategy to directly measure variations of atmospheric transmittance at optical wavelengths and application of these measurements to calibration of ground-based observations. This strategy makes use of measurements of the spectra of a small catalog of bright 'probe' stars as they progress across the sky and back-light the atmosphere. The signatures of optical absorption by different atmospheric constituents are recognized in these spectra by their characteristic dependences on wavelength and airmass. State-of-the-art models of atmospheric radiation transport and modern codes are used to accurately compute atmospheric extinction over a wide range of observing conditions. We present results of an observing campaign that demonstrate that correction for extinction due to molecular constituents and aerosols can be done with precisions of a few millimagnitudes with this technique.

  4. Lightweight Integrated Optical Sensor for Atmospheric Measurements on Mobile Platforms

    SciTech Connect (OSTI)

    Parameswaran, Krishnan R. [Physical Sciences Inc.

    2013-12-02T23:59:59.000Z

    The goal of the Phase I program was to develop a novel open path sensor platform technology based on integration of semiconductor waveguides with efficient optoelectronic components on a monolithic platform. The successful Phase I effort resulted in demonstration of a novel optical resonator structure based on semiconductor high contrast gratings (HCGs) that will enable implementation of an ultra-compact, low-power gas sensor suitable for use on mobile platforms. Extensive numerical modeling was performed to design a device optimized for measuring CO2 at a wavelength for which a laser was available for proof of concept. Devices were fabricated and tested to match the target wavelength, angle, and operating temperature. This demonstration is the first implementation of HCGs at the wavelengths of interest and shows the flexibility of the proposed architecture for gas sensing applications. The measured cavity Q was lower than anticipated due to fabrication process challenges. The PSI and UC Berkeley team has identified solutions to these challenges and will produce optimized devices in a Phase II program where a prototype sensor will be fabricated and tested.

  5. Lattice-matched epitaxial GaInAsSb/GaSb thermophotovoltaic devices

    SciTech Connect (OSTI)

    Wang, C.A.; Choi, H.K.; Turner, G.W.; Spears, D.L.; Manfra, M.J. [Massachusetts Inst. of Tech., Lexington, MA (United States). Lincoln Lab.; Charache, G.W. [Lockheed Martin, Inc., Schenectady, NY (United States)

    1997-05-01T23:59:59.000Z

    The materials development of Ga{sub 1{minus}x}In{sub x}As{sub y}Sb{sub 1{minus}y} alloys for lattice-matched thermophotovoltaic (TPV) devices is reported. Epilayers with cutoff wavelength 2--2.4 {micro}m at room temperature and lattice-matched to GaSb substrates were grown by both low-pressure organometallic vapor phase epitaxy and molecular beam epitaxy. These layers exhibit high optical and structural quality. For demonstrating lattice-matched thermophotovoltaic devices, p- and n-type doping studies were performed. Several TPV device structures were investigated, with variations in the base/emitter thicknesses and the incorporation of a high bandgap GaSb or AlGaAsSb window layer. Significant improvement in the external quantum efficiency is observed for devices with an AlGaAsSb window layer compared to those without one.

  6. Atmospheric effects of nuclar war aerosols in general circulation model simulations: Influence of smoke optical properties

    SciTech Connect (OSTI)

    Thompson, S.L.; Ramaswamy, V.; Covey, C.

    1987-09-20T23:59:59.000Z

    A global atmospheric general circulation model (GCM) is modified to include radiative transfer parameterizations for the absorption and scattering of solar radiation and the absorption of thermal infrared (IR) radiation by smoke aerosols. The solar scattering modifications include a parameterization for diagnosing smoke optical properties as a function of the time- and space-dependent smoke particle radii. The aerosol IR modifications allow for both the ''grey'' absorber approximation and a broadband approximation that resolves the aerosol absorption in four spectral intervals. We examine the sensitivity of some GCM-simulated atmospheric and climatic effects to the optical properties and radiative transfer parameterizations used in studies of massive injections of smoke. Specifically, we test the model response to solar scattering versus nonscattering smoke, variations in prescribed smoke single scattering albedo and IR specific absorption, and interactive versus fixed smoke optical properties. Hypothetical nuclear war created smoke scenarios assume the July injection of 60 or 180 Tg of smoke over portions of the mid-latitude land areas of the northern hemisphere. Atmospheric transport and scavenging of the smoke are included. Nonscattering smoke cases produce roughly 40 Wm/sup -2/ more Earth-atmosphere solar irradiance absorption over the northern hemisphere, when compared to scattering smoke cases having equivalent specific absorption efficiencies. Varying the elemental carbon content of smoke over a plausible range produces a 4/sup 0/--6 /sup 0/C change in average mid-latitude land surface temperature, and a variation of about 0.1 in zonally averaged planetary albedo in the northern hemisphere.

  7. Dependence of the ground-state transition energy versus optical pumping in GaAsSb/InGaAs/GaAs heterostructures

    SciTech Connect (OSTI)

    Morozov, S. V.; Kryzhkov, D. I., E-mail: krizh@ipmras.ru; Aleshkin, V. Ya. [Institute for Physics of Microstructures, RAS, 603950 Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod (Russian Federation); Yablonsky, A. N.; Krasilnik, Z. F. [Institute for Physics of Microstructures, RAS, 603950 Nizhny Novgorod (Russian Federation); Zvonkov, B. N.; Vikhrova, O. V. [Physical-Technical Research Institute, Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod (Russian Federation)

    2014-01-13T23:59:59.000Z

    In this work, we report on the time-resolved photoluminescence studies of a double quantum well In{sub 0.2}Ga{sub 0.8}As/GaAs{sub 0.8}Sb{sub 0.2}/GaAs heterostructure which, in contrast to the GaAsSb/GaAs structures, is expected to provide effective confinement of electrons due to additional InGaAs layer. The studies at 4.2?K have revealed a complicated nonmonotonic dependence of the ground-state transition energy on the concentration of nonequilibrium charge carriers in the quantum well. The effect observed in this work is important in terms of creating sources of radiation, including stimulated emission, on the basis of InGaAs/GaAsSb/GaAs structures.

  8. INFRARED SPECTRA AND OPTICAL CONSTANTS OF NITRILE ICES RELEVANT TO TITAN's ATMOSPHERE

    SciTech Connect (OSTI)

    Moore, Marla H.; Hudson, Reggie [NASA Goddard Space Flight Center, Code 691, Greenbelt, MD 20771 (United States); Ferrante, Robert F. [Chemistry Department, US Naval Academy, 572 Holloway Road, Annapolis, MD 21402 (United States); James Moore, W., E-mail: Marla.h.moore@nasa.go [USRA NASA Goddard Space Flight Center, Code 691, Greenbelt, MD 20771 (United States)

    2010-11-15T23:59:59.000Z

    Spectra and optical constants of nitrile ices known or suspected to be in Titan's atmosphere are presented from 2.0 to 333.3 {mu}m ({approx}5000-30 cm{sup -1}). These results are relevant to the ongoing modeling of Cassini CIRS observations of Titan's winter pole. Ices studied are: HCN, hydrogen cyanide; C{sub 2}N{sub 2}, cyanogen; CH{sub 3}CN, acetonitrile; C{sub 2}H{sub 5}CN, propionitrile; and HC{sub 3}N, cyanoacetylene. For each of these molecules, we also report new cryogenic measurements of the real refractive index, n, determined in both the amorphous and crystalline phases at 670 nm. These new values have been incorporated into our optical constant calculations. Spectra were measured and optical constants were calculated for each nitrile at a variety of temperatures, including, but not limited to, 20, 35, 50, 75, 95, and 110 K, in both the amorphous phase and the crystalline phase. This laboratory effort used a dedicated FTIR spectrometer to record transmission spectra of thin-film ice samples. Laser interference was used to measure film thickness during condensation onto a transparent cold window attached to the tail section of a closed-cycle helium cryostat. Optical constants, real (n) and imaginary (k) refractive indices, were determined using Kramers-Kronig analysis. Our calculation reproduces the complete spectrum, including all interference effects.

  9. Study of nanosecond laser-produced plasmas in atmosphere by spatially resolved optical emission spectroscopy

    SciTech Connect (OSTI)

    Wei, Wenfu; Wu, Jian; Li, Xingwen; Jia, Shenli; Qiu, Aici [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 XianNing West Road, Xi'an, Shaanxi Province 710049 (China)] [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, No. 28 XianNing West Road, Xi'an, Shaanxi Province 710049 (China)

    2013-09-21T23:59:59.000Z

    We investigate the evolution of the species from both the target and the air, and the plasma parameter distribution of the nanosecond laser-produced plasmas in atmospheric air. The technique used is spatially resolved optical emission spectroscopy. It is argued that the N II from the air, which is distributed over a wider region than the target species in the early stages of the discharge, is primarily formed by the shock wave. The ionized species have a larger expansion velocity than the excited atoms in the first ?100 ns, providing direct evidence for space-charge effects. The electron density decreases with the distance from the target surface in the early stages of the discharge, and both the electron density and the excited temperature variation in the axial direction are found to become insignificant at later stages.

  10. Development of an electronic device quality aluminum antimonide (AlSb) semiconductor for solar cell applications

    DOE Patents [OSTI]

    Sherohman, John W; Yee, Jick Hong; Combs, III, Arthur W

    2014-11-11T23:59:59.000Z

    Electronic device quality Aluminum Antimonide (AlSb)-based single crystals produced by controlled atmospheric annealing are utilized in various configurations for solar cell applications. Like that of a GaAs-based solar cell devices, the AlSb-based solar cell devices as disclosed herein provides direct conversion of solar energy to electrical power.

  11. Speciation of Sb in airborne particulate matter, vehicle brake linings, and brake pad wear residues

    E-Print Network [OSTI]

    Short, Daniel

    Speciation of Sb in airborne particulate matter, vehicle brake linings, and brake pad wear residues: XAS XANES EXAFS Antimony Particulate matter Brake linings a b s t r a c t Insights into the speciation of Sb in samples of brake linings, brake pad wear residues, road dust, and atmospheric particulate

  12. An Atmospheric Radiation Measurement Value-Added Product to Retrieve Optically Thin Cloud Visible Optical Depth using Micropulse Lidar

    SciTech Connect (OSTI)

    Lo, C; Comstock, JM; Flynn, C

    2006-10-01T23:59:59.000Z

    The purpose of the Micropulse Lidar (MPL) Cloud Optical Depth (MPLCOD) Value-Added Product (VAP) is to retrieve the visible (short-wave) cloud optical depth for optically thin clouds using MPL. The advantage of using the MPL to derive optical depth is that lidar is able to detect optically thin cloud layers that may not be detected by millimeter cloud radar or radiometric techniques. The disadvantage of using lidar to derive optical depth is that the lidar signal becomes attenuation limited when ? approaches 3 (this value can vary depending on instrument specifications). As a result, the lidar will not detect optically thin clouds if an optically thick cloud obstructs the lidar beam.

  13. Magneto-optical effects in semimetallic Bi1–xSbx (x=0.015)

    SciTech Connect (OSTI)

    Dordevic, S. V.; Wolf, M. S.; Stojilovic, N.; Nikolic, M. V.; Vujatovic, S. S.; Nikolic, P. M.; Tung, L. C.

    2012-09-01T23:59:59.000Z

    We report the results of infrared and magneto-optical spectroscopy study on electrodynamic response of bismuth doped with 1.5% of antimony. The spectra are presented for temperatures down to 4.2 K, and in magnetic fields as high as 18 T. The results reveal strong magneto-optical activity, similar to pure bismuth, however there are some differences introduced by antimony doping. Analysis of optical functions reveals that the two type of charge carriers respond differently to external magnetic field. Finally, when the system enters the extreme quantum regime, both the inter- and intraband Landau Level transition are observed in the spectra.

  14. GaInAsSb/A1GaAsSb/Sb Thermophotovoltaic Devices With an Internal Back-Surface Reflector Formed by Wafer Bonding

    SciTech Connect (OSTI)

    C.A. Wang; R.K. Huang; D.A. Shiau; M.K. Connors; P.G. Murphy; P.W. O'brien; A.C. Anderson; D.M. DePoy; G. Nichols; M.N. Palmasiano

    2002-12-18T23:59:59.000Z

    A novel implementation for GAInAsSb/AlGaAsSb/GaSb TPV cells with an internal back-surface reflector (BSR) formed by wafer bonding to GaAs is demonstrated. The SiO{sub x}/Ti/Au internal BSR enhances optical absorption within the device, while the dielectric layer provides electrical isolation. This configuration has the potential to improve TPV device performance; is compatible with monolithic series-interconnection of TPV cells for building voltage; and can mitigate the requirements of filters used for front-surface spectral control. At a short-circuit density of 0.4 A/cm{sup 2}, the open-circuit voltage of a single TPV cell is 0.2 V, compared to 0.37 and 1.8 V for 2- and 10-junction series-interconnected TPV cells, respectively.

  15. Low loss hollow optical-waveguide connection from atmospheric pressure to ultra-high vacuum

    SciTech Connect (OSTI)

    Ermolov, A.; Mak, K. F.; Tani, F.; Hölzer, P.; Travers, J. C. [Max Planck Institute for the Science of Light, Günther-Scharowsky-Str. 1, 91058 Erlangen (Germany)] [Max Planck Institute for the Science of Light, Günther-Scharowsky-Str. 1, 91058 Erlangen (Germany); Russell, P. St. J. [Max Planck Institute for the Science of Light, Günther-Scharowsky-Str. 1, 91058 Erlangen (Germany) [Max Planck Institute for the Science of Light, Günther-Scharowsky-Str. 1, 91058 Erlangen (Germany); Department of Physics, University of Erlangen-Nuremberg, Günther-Scharowsky-Str. 1, 91058 Erlangen (Germany)

    2013-12-23T23:59:59.000Z

    A technique for optically accessing ultra-high vacuum environments, via a photonic-crystal fiber with a long small hollow core, is described. The small core and the long bore enable a pressure ratio of over 10{sup 8} to be maintained between two environments, while permitting efficient and unimpeded delivery of light, including ultrashort optical pulses. This delivery can be either passive or can encompass nonlinear optical processes such as optical pulse compression, deep UV generation, supercontinuum generation, or other useful phenomena.

  16. Effect of Solar Radiation on the Optical Properties and Molecular Composition of Laboratory Proxies of Atmospheric Brown Carbon

    SciTech Connect (OSTI)

    Lee, Hyun Ji; Aiona, Paige K.; Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

    2014-09-02T23:59:59.000Z

    Sources, optical properties, and chemical composition of atmospheric brown carbon (BrC) aerosol are uncertain, making it challenging to estimate its contribution to radiative forcing. Furthermore, optical properties of BrC may change significantly during its atmospheric aging. We examined the effect of solar photolysis on the molecular composition, mass absorption coefficient, and fluorescence of secondary organic aerosol prepared by high-NOx photooxidation of naphthalene (NAP SOA). The aqueous solutions of NAP SOA was observed to photobleach with an effective half-time of ?15 hours (with sun in its zenith) for the loss of the near-UV (300 -400 nm) absorbance. The molecular composition of NAP SOA was significantly modified by photolysis, with the average SOA formula changing from C14.1H14.5O5.1N0.08 to C11.8H14.9O4.5N0.02 after 4 hours of irradiation. The average O/C ratio did not change significantly, however, suggesting that it is not a good metric for assessing the extent of photolysis-driven aging in NAP SOA (and in BrC in general). In contrast to NAP SOA, the photolysis of BrC material produced by aqueous reaction of limonene+O3 SOA (LIM/O3 SOA) with ammonium sulfate was much faster, but it did not result in a significant change in the molecular level composition. The characteristic absorbance of the aged LIM/O3 SOA in the 450-600 nm range decayed with an effective half-time of <0.5 hour. This result emphasizes the highly variable and dynamic nature of different types of atmospheric BrC.

  17. Relaxation of photoinduced spins and carriers in ferromagnetic InMnSb films

    SciTech Connect (OSTI)

    Nontapot, K.; Kini, R. N.; Gifford, A.; Merritt, T. R.; Khodaparast, G. A.; Wojtowicz, T.; Liu, X.; Furdyna, J. K. [Department of Physics, Virginia Tech, Blacksburg, Virginia 24061 (United States); Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw (Poland); Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

    2007-04-02T23:59:59.000Z

    The authors report time resolved measurements and control of photoinduced spin and carrier relaxations in InMnSb ferromagnetic films with 2% Mn content (grown by low-temperature molecular beam epitaxy) using femtosecond laser pulses, and compare them to analogous measurements on InBeSb and InSb films. In this work, magneto-optical Kerr effect and standard pump-probe techniques provided a direct measure of the photoexcited spin and carrier lifetimes, respectively. They observe decrease in relaxations times in the high laser fluence regime and an absence of temperature dependence of the relaxation times.

  18. High-temperature luminescence in an n-GaSb/n-InGaAsSb/p-AlGaAsSb light-emitting heterostructure with a high potential barrier

    SciTech Connect (OSTI)

    Petukhov, A. A., E-mail: andrey-rus29@rambler.ru; Zhurtanov, B. E.; Kalinina, K. V.; Stoyanov, N. D.; Salikhov, H. M.; Mikhailova, M. P.; Yakovlev, Yu. P. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

    2013-09-15T23:59:59.000Z

    The electroluminescent properties of an n-GaSb/n-InGaAsSb/p-AlGaAsSb heterostructure with a high potential barrier in the conduction band (large conduction-band offset) at the n-GaSb/n-InGaAsSb type-II heterointerface ({Delta}E{sub c} = 0.79 eV) are studied. Two bands with peaks at 0.28 and 0.64 eV at 300 K, associated with radiative recombination in n-InGaAsSb and n-GaSb, respectively, are observed in the electroluminescence (EL) spectrum. In the entire temperature range under study, T = 290-480 K, additional electron-hole pairs are formed in the n-InGaAsSb active region by impact ionization with hot electrons heated as a result of the conduction-band offset. These pairs contribute to radiative recombination, which leads to a nonlinear increase in the EL intensity and output optical power with increasing pump current. A superlinear increase in the emission power of the long-wavelength band is observed upon heating in the temperature range T = 290-345 K, and a linear increase is observed at T > 345 K. This work for the first time reports an increase in the emission power of a light-emitting diode structure with increasing temperature. It is shown that this rise is caused by a decrease in the threshold energy of the impact ionization due to narrowing of the band gap of the active region.

  19. Long-Term, Autonomous Measurement of Atmospheric Carbon Dioxide Using an Ormosil Nanocomposite-Based Optical Sensor

    SciTech Connect (OSTI)

    Kisholoy Goswami

    2005-10-11T23:59:59.000Z

    The goal of this project is to construct a prototype carbon dioxide sensor that can be commercialized to offer a low-cost, autonomous instrument for long-term, unattended measurements. Currently, a cost-effective CO2 sensor system is not available that can perform cross-platform measurements (ground-based or airborne platforms such as balloon and unmanned aerial vehicle (UAV)) for understanding the carbon sequestration phenomenon. The CO2 sensor would support the research objectives of DOE-sponsored programs such as AmeriFlux and the North American Carbon Program (NACP). Global energy consumption is projected to rise 60% over the next 20 years and use of oil is projected to increase by approximately 40%. The combustion of coal, oil, and natural gas has increased carbon emissions globally from 1.6 billion tons in 1950 to 6.3 billion tons in 2000. This figure is expected to reach 10 billon tons by 2020. It is important to understand the fate of this excess CO2 in the global carbon cycle. The overall goal of the project is to develop an accurate and reliable optical sensor for monitoring carbon dioxide autonomously at least for one year at a point remote from the actual CO2 release site. In Phase I of this project, InnoSense LLC (ISL) demonstrated the feasibility of an ormosil-monolith based Autonomous Sensor for Atmospheric CO2 (ASAC) device. All of the Phase I objectives were successfully met.

  20. Quaternary InGaAsSb Thermophotovoltaic Diodes

    SciTech Connect (OSTI)

    MW Dashiell; JF Beausang; H Ehsani; GJ Nichols; DM Depoy; LR Danielson; P Talamo; KD Rahner; EJ Brown; SR Burger; PM Foruspring; WF Topper; PF Baldasaro; CA Wang; R Huang; M Connors; G Turner; Z Shellenbarger; G Taylor; J Li; R Martinelli; D Donetski; S Anikeev; G Belenky; S Luryi

    2006-03-09T23:59:59.000Z

    In{sub x}Ga{sub 1-x}As{sub y}Sb{sub 1-y} thermophotovoltaic (TPV) diodes were grown lattice-matched to GaSb substrates by Metal Organic Vapor Phase Epitaxy (MOVPE) in the bandgap range of E{sub G} = 0.5 to 0.6eV. InGaAsSb TPV diodes, utilizing front-surface spectral control filters, are measured with thermal-to-electric conversion efficiency and power density of {eta}{sub TPV} = 19.7% and PD =0.58 W/cm{sup 2} respectively for a radiator temperature of T{sub radiator} = 950 C, diode temperature of T{sub diode} = 27 C, and diode bandgap of E{sub G} = 0.53eV. Practical limits to TPV energy conversion efficiency are established using measured recombination coefficients and optical properties of front surface spectral control filters, which for 0.53eV InGaAsSb TPV energy conversion is {eta}{sub TPV} = 28% and PD = 0.85W/cm{sup 2} at the above operating temperatures. The most severe performance limits are imposed by (1) diode open-circuit voltage (VOC) limits due to intrinsic Auger recombination and (2) parasitic photon absorption in the inactive regions of the module. Experimentally, the diode V{sub OC} is 15% below the practical limit imposed by intrinsic Auger recombination processes. Analysis of InGaAsSb diode electrical performance vs. diode architecture indicate that the V{sub OC} and thus efficiency is limited by extrinsic recombination processes such as through bulk defects.

  1. Electrochemical Insertion/extraction of Lithium in Multiwall Carbon Nanotube/Sb and SnSb?.? Nanocomposites

    E-Print Network [OSTI]

    Chen, Wei Xiang

    Multiwall carbon nanotubes (CNTs) were synthesized by catalytic chemical vapor deposition of acetylene and used as templates to prepare CNT-Sb and CNT-SnSb?.? nanocomposites via the chemical reduction of SnCl? and SbCl? ...

  2. Structural investigation on Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses using x-ray photoelectron spectra

    SciTech Connect (OSTI)

    Wei, Wen-Hou [Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Department of Applied Physics, Chongqing University, Chongqing 401331 (China); Xiang, Shen [College of Information Science and Engineering, Ningbo University, Ningbo 315211 (China); Xu, Si-Wei; Wang, Rong-Ping, E-mail: rongping.wang@anu.edu.au [Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Fang, Liang [Department of Applied Physics, Chongqing University, Chongqing 401331 (China)

    2014-05-14T23:59:59.000Z

    The structure of Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses (x?=?7.5, 10, 15, 20, 25, 27.5, 30, and 32.5 at. %) has been investigated by x-ray photoelectron spectroscopy (XPS). Different structural units have been extracted and characterized by decomposing XPS core level spectra, the evolution of the relative concentration of each structural unit indicates that, the relative contributions of Se-trimers and Se-Se-Ge(Sb) structure decrease with increasing Ge content until they become zero at chemically stoichiometric glasses of Ge{sub 25}Sb{sub 10}Se{sub 65}, and then the homopolar bonds like Ge-Ge and Sb-Sb begin to appear in the spectra. Increase of homopolar bonds will extend band-tails into the gap and narrow the optical band gap. Thus, the glass with a stoichiometric composition generally has fewer defective bonds and larger optical bandgap.

  3. atmospheres thin atmospheres: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  4. Semiconductor structures having electrically insulating and conducting portions formed from an AlSb-alloy layer

    DOE Patents [OSTI]

    Spahn, Olga B. (Albuquerque, NM); Lear, Kevin L. (Albuquerque, NM)

    1998-01-01T23:59:59.000Z

    A semiconductor structure. The semiconductor structure comprises a plurality of semiconductor layers formed on a substrate including at least one layer of a III-V compound semiconductor alloy comprising aluminum (Al) and antimony (Sb), with at least a part of the AlSb-alloy layer being chemically converted by an oxidation process to form superposed electrically insulating and electrically conducting portions. The electrically insulating portion formed from the AlSb-alloy layer comprises an oxide of aluminum (e.g. Al.sub.2 O.sub.3), while the electrically conducting portion comprises Sb. A lateral oxidation process allows formation of the superposed insulating and conducting portions below monocrystalline semiconductor layers for forming many different types of semiconductor structures having particular utility for optoelectronic devices such as light-emitting diodes, edge-emitting lasers, vertical-cavity surface-emitting lasers, photodetectors and optical modulators (waveguide and surface normal), and for electronic devices such as heterojunction bipolar transistors, field-effect transistors and quantum-effect devices. The invention is expected to be particularly useful for forming light-emitting devices for use in the 1.3-1.6 .mu.m wavelength range, with the AlSb-alloy layer acting to define an active region of the device and to effectively channel an electrical current therein for efficient light generation.

  5. Semiconductor structures having electrically insulating and conducting portions formed from an AlSb-alloy layer

    DOE Patents [OSTI]

    Spahn, O.B.; Lear, K.L.

    1998-03-10T23:59:59.000Z

    The semiconductor structure comprises a plurality of semiconductor layers formed on a substrate including at least one layer of a III-V compound semiconductor alloy comprising aluminum (Al) and antimony (Sb), with at least a part of the AlSb-alloy layer being chemically converted by an oxidation process to form superposed electrically insulating and electrically conducting portions. The electrically insulating portion formed from the AlSb-alloy layer comprises an oxide of aluminum (e.g., Al{sub 2}O{sub 3}), while the electrically conducting portion comprises Sb. A lateral oxidation process allows formation of the superposed insulating and conducting portions below monocrystalline semiconductor layers for forming many different types of semiconductor structures having particular utility for optoelectronic devices such as light-emitting diodes, edge-emitting lasers, vertical-cavity surface-emitting lasers, photodetectors and optical modulators (waveguide and surface normal), and for electronic devices such as heterojunction bipolar transistors, field-effect transistors and quantum-effect devices. The invention is expected to be particularly useful for forming light-emitting devices for use in the 1.3--1.6 {mu}m wavelength range, with the AlSb-alloy layer acting to define an active region of the device and to effectively channel an electrical current therein for efficient light generation. 10 figs.

  6. Abundance analysis of SB2 binary stars with HgMn primaries

    E-Print Network [OSTI]

    T. Ryabchikova

    1998-05-06T23:59:59.000Z

    We present a short review of the abundances in the atmospheres of SB2 systems with Mercury-Manganese (HgMn) primaries. Up to now a careful study has been made for both components of 8 out of 17 known SB2 binaries with orbital periods shorter than 100 days and mass ratio ranging from 1.08 to 2.2. For all eight systems we observe a lower Mn abundance in the secondary's atmospheres than in the primary's. Significant difference in the abundances is also found for some peculiar elements such as Ga, Xe, Pt. All secondary stars with effective temperatures less than 10000 K show abundance characteristics typical of the metallic-line stars.

  7. Optical emission spectroscopic diagnostics of a non-thermal atmospheric pressure helium-oxygen plasma jet for biomedical applications

    SciTech Connect (OSTI)

    Thiyagarajan, Magesh; Sarani, Abdollah; Nicula, Cosmina [Plasma Engineering Research Laboratory (PERL), College of Science and Engineering, Texas A and M University-Corpus Christi, Texas 78412 (United States)] [Plasma Engineering Research Laboratory (PERL), College of Science and Engineering, Texas A and M University-Corpus Christi, Texas 78412 (United States)

    2013-06-21T23:59:59.000Z

    In this work, we have applied optical emission spectroscopy diagnostics to investigate the characteristics of a non-thermal atmospheric pressure helium plasma jet. The discharge characteristics in the active and afterglow region of the plasma jet, that are critical for biomedical applications, have been investigated. The voltage-current characteristics of the plasma discharge were analyzed and the average plasma power was measured to be around 18 W. The effect of addition of small fractions of oxygen at 0.1%-0.5% on the plasma jet characteristics was studied. The addition of oxygen resulted in a decrease in plasma plume length due to the electronegativity property of oxygen. Atomic and molecular lines of selected reactive plasma species that are considered to be useful to induce biochemical reactions such as OH transitions A{sup 2}{Sigma}{sup +}({nu}=0,1){yields}X{sup 2}{Pi}({Delta}{nu}=0) at 308 nm and A{sup 2}{Sigma}{sup +}({nu}=0,1){yields}X{sup 2}{Pi}({Delta}{nu}=1) at 287 nm, O I transitions 3p{sup 5}P{yields}3s{sup 5}S{sup 0} at 777.41 nm, and 3p{sup 3}P{yields}3s{sup 3}S{sup 0} at 844.6 nm, N{sub 2}(C-B) second positive system with electronic transition C{sup 3}{Pi}{sub u}{sup {yields}}B{sup 3}{Pi}{sub g}'' in the range of 300-450 nm and N{sub 2}{sup +}(B-X) first negative system with electronic transition B{sup 2}{Sigma}{sub u}{sup +}{yields}X{sup 2}{Sigma}{sub g}{sup +}({Delta}{nu}=0) at 391.4 nm have been studied. The atomic emission lines of helium were identified, including the He I transitions 3p{sup 3}P{sup 0}{yields}2s{sup 3}S at 388.8 nm, 3p{sup 1}P{sup 0}{yields} 2s{sup 1}S at 501.6 nm, 3d{sup 3}D{yields}2p{sup 3}P{sup 0} at 587.6 nm, 3d{sup 1}D{yields}2p{sup 1}P{sup 0} at 667.8 nm, 3s{sup 3}S{sup 1}{yields}2p{sup 3}P{sup 0} at 706.5 nm, 3s{sup 1}S{sup 0}{yields}2p{sup 1}P{sup 0} at 728.1 nm, and H{sub {alpha}} transition 2p-3d at 656.3 nm. Using a spectral fitting method, the OH radicals at 306-312 nm, the rotational and vibrational temperatures equivalent to gas temperatures of the discharge was measured and the effective non-equilibrium nature of the plasma jet was demonstrated. Our results show that, in the entire active plasma region, the gas temperature remains at 310 {+-} 25 K and 340 {+-} 25 K and it increases to 320 {+-} 25 K and 360 {+-} 25 K in the afterglow region of the plasma jet for pure helium and helium/oxygen (0.1%) mixture, respectively. Additionally, the vibrational temperatures range from 2200 {+-} 100 K and 2500 {+-} 100 K for pure helium and helium/oxygen (0.1%) mixture, respectively. The plasma jet was tested on heat sensitive polymer films used in biomedical applications such as polyethylene terephthalate and poly-L-lactide samples continuously for several minutes without causing any physical or thermal damage to the films. The plasma jet produces significant reactive species of interest while the gas temperatures remain very low demonstrating its potential for a range of biomedical applications.

  8. Wafer Bonding and Epitaxial Transfer of GaSb-based Epitaxy to GaAs for Monolithic Interconnection of Thermophotovoltaic Devices

    SciTech Connect (OSTI)

    C.A. Wang; D.A. Shiau; P.G. Murphy; P.W. O'brien; R.K. Huang; M.K. Connors; A.C. Anderson; D. Donetsky; S. Anikeev; G. Belenky; D.M. Depoy; G. Nichols

    2003-06-16T23:59:59.000Z

    GaInAsSb/AlGaAsSb/InAsSb/GaSb epitaxial layers were bonded to semi-insulating GaAs handle wafers with SiO{sub x}/Ti/Au as the adhesion layer for monolithic interconnection of thermophotovoltaic (TPV) devices. Epitaxial transfer was completed by removal of the GaSb substrate, GaSb buffer, and InAsSb etch-stop layer by selective chemical etching. The SiO{sub x}/TiAu provides not only electrical isolation, but also high reflectivity and is used as an internal back-surface reflector. Characterization of wafer-bonded epitaxy by high-resolution x-ray diffraction and time-decay photoluminescence indicates minimal residual stress and enhancement in optical quality. 0.54-eV GaInAsSb cells were fabricated and monolithically interconnected in series. A 10-junction device exhibited linear voltage building with an open-circuit voltage of 1.8 V.

  9. DWPF simulant CPC studies for SB8

    SciTech Connect (OSTI)

    Koopman, D. C.; Zamecnik, J. R.

    2013-06-25T23:59:59.000Z

    The Savannah River National Laboratory (SRNL) accepted a technical task request (TTR) from Waste Solidification Engineering to perform simulant tests to support the qualification of Sludge Batch 8 (SB8) and to develop the flowsheet for SB8 in the Defense Waste Processing Facility (DWPF). These efforts pertained to the DWPF Chemical Process Cell (CPC). Separate studies were conducted for frit development and glass properties (including REDOX). The SRNL CPC effort had two primary phases divided by the decision to drop Tank 12 from the SB8 constituents. This report focuses on the second phase with SB8 compositions that do not contain the Tank 12 piece. A separate report will document the initial phase of SB8 testing that included Tank 12. The second phase of SB8 studies consisted of two sets of CPC studies. The first study involved CPC testing of an SB8 simulant for Tank 51 to support the CPC demonstration of the washed Tank 51 qualification sample in the SRNL Shielded Cells facility. SB8-Tank 51 was a high iron-low aluminum waste with fairly high mercury and moderate noble metal concentrations. Tank 51 was ultimately washed to about 1.5 M sodium which is the highest wash endpoint since SB3-Tank 51. This study included three simulations of the DWPF Sludge Receipt and Adjustment Tank (SRAT) cycle and Slurry Mix Evaporator (SME) cycle with the sludge-only flowsheet at nominal DWPF processing conditions and three different acid stoichiometries. These runs produced a set of recommendations that were used to guide the successful SRNL qualification SRAT/SME demonstration with actual Tank 51 washed waste. The second study involved five SRAT/SME runs with SB8-Tank 40 simulant. Four of the runs were designed to define the acid requirements for sludge-only processing in DWPF with respect to nitrite destruction and hydrogen generation. The fifth run was an intermediate acid stoichiometry demonstration of the coupled flowsheet for SB8. These runs produced a set of processing recommendations for DWPF along with some data related to Safety Class documentation at DWPF. Some significant observations regarding SB8 follow: Reduced washing in Tank 51 led to an increase in the wt.% soluble solids of the DWPF feed. If wt.% total solids for the SRAT and SME product weren’t adjusted upward to maintain insoluble solids levels similar to past sludge batches, then the rheological properties of the slurry went below the low end of the DWPF design bases for the SRAT and SME. Much higher levels of dissolved manganese were found in the SRAT and SME products than in recent sludge batches. Closed crucible melts were more reduced than expected. The working hypothesis is that the soluble Mn is less oxidizing than assumed in the REDOX calculations. A change in the coefficient for Mn in the REDOX equation was recommended in a separate report. The DWPF (Hsu) stoichiometric acid equation was examined in detail to better evaluate how to control acid in DWPF. The existing DWPF equation can likely be improved without changing the required sample analyses through a paper study using existing data. The recommended acid stoichiometry for initial SB8 SRAT batches is 115-120% stoichiometry until some processing experience is gained. The conservative range (based on feed properties) of stoichiometric factors derived in this study was from 110-147%, but SRNL recommends using only the lower half of this range, 110-126% even after initial batches provide processing experience. The stoichiometric range for sludge-only processing appears to be suitable for coupled operation based on results from the run in the middle of the range. Catalytic hydrogen was detectable (>0.005 vol%) in all SRAT and SME cycles. Hydrogen reached 30-35% of the SRAT and SME limits at the mid-point of the stoichiometry window (bounding noble metals and acid demand).

  10. Electrical Engineering SB Rev. Nov 2013 1/3

    E-Print Network [OSTI]

    Electrical Engineering SB Rev. Nov 2013 1/3 Plan of Study for the Electrical Engineering of Study Form is for a (Circle One): DECLARATION REVISION The S.B. Program in Electrical Engineering must ­ System Programming & Machine Organization 1.00 __________ #12;Electrical Engineering SB Rev. Nov 2013

  11. Electrical Engineering SB Rev. Nov 2014 1/3

    E-Print Network [OSTI]

    Electrical Engineering SB Rev. Nov 2014 1/3 Plan of Study for the Electrical Engineering of Study Form is for a (Circle One): DECLARATION REVISION The S.B. Program in Electrical Engineering must ­ System Programming & Machine Organization 1.00 __________ Sophomore Forum #12;Electrical Engineering SB

  12. Thermoelectric properties of ZnSb films grown by MOCVD

    SciTech Connect (OSTI)

    Venkatasubramanian, R.; Watko, E.; Colpitts, T.

    1997-07-01T23:59:59.000Z

    The thermoelectric properties of ZnSb films grown by metallorganic chemical vapor deposition (MOCVD) are reported. The growth conditions necessary to obtain stoichiometric ZnSb films and the effects of various growth parameters on the electrical conductivity and Seebeck coefficients of the films are described. The as-grown ZnSb films are p-type. It was observed that the thicker ZnSb films offer improved carrier mobilities and lower free-carrier concentration levels. The Seebeck coefficient of ZnSb films was found to rise rapidly at approximately 160 C. The thicker films, due to the lower doping levels, indicate higher Seebeck coefficients between 25 to 200 C. A short annealing of the ZnSb film at temperatures of {approximately}200 C results in reduced free-carrier level. Thermal conductivity measurements of ZnSb films using the 3-{omega} method are also presented.

  13. Recent progress in InGaAsSb/GaSb TPV devices

    SciTech Connect (OSTI)

    Shellenbarger, Z.A.; Mauk, M.G.; DiNetta, L.C. [AstroPower, Inc., Newark, DE (United States); Charache, G.W. [Lockheed Martin Corp., Schenectady, NY (United States)

    1996-05-01T23:59:59.000Z

    AstroPower is developing InGaAsSb thermophotovoltaic (TPV) devices. This photovoltaic cell is a two-layer epitaxial InGaAsSb structure formed by liquid-phase epitaxy on a GaSb substrate. The (direct) bandgap of the In{sub 1{minus}x}Ga{sub x}As{sub 1{minus}y}Sb{sub y} alloy is 0.50 to 0.55 eV, depending on its exact alloy composition (x,y); and is closely lattice-matched to the GaSb substrate. The use of the quaternary alloy, as opposed to a ternary alloy--such as, for example InGaAs/InP--permits low bandgap devices optimized for 1,000 to 1,500 C thermal sources with, at the same time, near-exact lattice matching to the GaSb substrate. Lattice matching is important since even a small degree of lattice mismatch degrades device performance and reliability and increases processing complexity. Internal quantum efficiencies as high as 95% have been measured at a wavelength of 2 microns. At 1 micron wavelengths, internal quantum efficiencies of 55% have been observed. The open-circuit voltage at currents of 0.3 A/cm{sup 2} is 0.220 volts and 0.280 V for current densities of 2 A/cm{sup 2}. Fill factors of 56% have been measured at 60 mA/cm{sup 2}. However, as current density increases there is some decrease in fill factor. The results to date show that the GaSb-based quaternary compounds provide a viable and high performance energy conversion solution for thermophotovoltaic systems operating with 1,000 to 1,500 C source temperatures.

  14. Raman Spectroscopy Determination of Hole Concentration in p-Type GaSb

    SciTech Connect (OSTI)

    Maslar JE, Hurst WS, Wang CA

    2007-04-05T23:59:59.000Z

    Room temperature p-type GaSb bulk coupled mode spectra were measured as a function of hole concentration. These spectra were obtained using an optical system based on 752.55 nm excitation in order to obtain more sensitivity to bulk GaSb coupled mode scattering than possible with visible wavelength excitation-based systems. A relatively simple spectral model for the electronic contribution to the dielectric function was evaluated for determination of hole concentration from the bulk coupled mode spectra. Optically-derived values for hole concentration were determined by minimizing the sum of the residuals squared between an experimental and simulated spectrum as a function of total hole concentration and a plasmon damping parameter. Hole concentrations obtained from the Raman spectroscopic measurements deviated from the values determined from single field Hall effect measurements that were corrected to account for two band conduction by {approx}20% to {approx}65%. These deviations were attributed to the limitations of the spectral model employed and uncertainties in GaSb materials properties.

  15. atmospheres: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  16. atmosphere: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  17. atmospherics: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  18. Carrier spin relaxation in GaInNAsSb/GaNAsSb/GaAs quantum well

    SciTech Connect (OSTI)

    Asami, T.; Nosho, H.; Tackeuchi, A. [Department of Applied Physics, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Li, L. H.; Harmand, J. C. [Laboratory for Photonics and Nanostructures-CNRS, Site Alcatel de Marcoussis, Route de Nozay, 91460 Marcoussis (France); Lu, S. L. [Suzhou Institute of Nano-tech and Nano-bionics, CAS, Dushu, Lake Higher Education Town, Ruoshui Road 398, Suzhou Industrial Park, Suzhou 215125 (China)

    2011-12-23T23:59:59.000Z

    We have investigated the carrier spin relaxation in GaInNAsSb/GaNAsSb/GaAs quantum well (QW) by time-resolved photoluminescence (PL) measurement. The sample consists of an 8-nm-thick GaIn{sub 0.36}N{sub 0.006}AsSb{sub 0.015} well, 5-nm-thick GaN{sub 0.01}AsSb{sub 0.11} intermediate barriers and 100-nm-thick GaAs barriers grown by molecular beam epitaxy on a GaAs(100) substrate. The spin relaxation time and recombination lifetime at 10 K are measured to be 228 ps and 151 ps, respectively. As a reference, we have also obtained a spin relaxation time of 125 ps and a recombination lifetime of 63 ps for GaInNAs/GaNAs/GaAs QW. This result shows that crystal quality is slightly improved by adding Sb, although these short carrier lifetimes mainly originate from a nonradiative recombination. These spin relaxation times are longer than the 36 ps spin relaxation time of InGaAs/InP QWs and shorter than the 2 ns spin relaxation time of GaInNAs/GaAs QW.

  19. DWPF Simulant CPC Studies For SB8

    SciTech Connect (OSTI)

    Newell, J. D.

    2013-09-25T23:59:59.000Z

    Prior to processing a Sludge Batch (SB) in the Defense Waste Processing Facility (DWPF), flowsheet studies using simulants are performed. Typically, the flowsheet studies are conducted based on projected composition(s). The results from the flowsheet testing are used to 1) guide decisions during sludge batch preparation, 2) serve as a preliminary evaluation of potential processing issues, and 3) provide a basis to support the Shielded Cells qualification runs performed at the Savannah River National Laboratory (SRNL). SB8 was initially projected to be a combination of the Tank 40 heel (Sludge Batch 7b), Tank 13, Tank 12, and the Tank 51 heel. In order to accelerate preparation of SB8, the decision was made to delay the oxalate-rich material from Tank 12 to a future sludge batch. SB8 simulant studies without Tank 12 were reported in a separate report.1 The data presented in this report will be useful when processing future sludge batches containing Tank 12. The wash endpoint target for SB8 was set at a significantly higher sodium concentration to allow acceptable glass compositions at the targeted waste loading. Four non-coupled tests were conducted using simulant representing Tank 40 at 110-146% of the Koopman Minimum Acid requirement. Hydrogen was generated during high acid stoichiometry (146% acid) SRAT testing up to 31% of the DWPF hydrogen limit. SME hydrogen generation reached 48% of of the DWPF limit for the high acid run. Two non-coupled tests were conducted using simulant representing Tank 51 at 110-146% of the Koopman Minimum Acid requirement. Hydrogen was generated during high acid stoichiometry SRAT testing up to 16% of the DWPF limit. SME hydrogen generation reached 49% of the DWPF limit for hydrogen in the SME for the high acid run. Simulant processing was successful using previously established antifoam addition strategy. Foaming during formic acid addition was not observed in any of the runs. Nitrite was destroyed in all runs and no N2O was detected during SME processing. Mercury behavior was consistent with that seen in previous SRAT runs. Mercury was stripped below the DWPF limit on 0.8 wt% for all runs. Rheology yield stress fell within or below the design basis of 1-5 Pa. The low acid Tank 40 run (106% acid stoichiometry) had the highest yield stress at 3.78 Pa.

  20. K2CsSb Cathode Development

    SciTech Connect (OSTI)

    Smedley,J.; Rao, T.; Wang, E.

    2008-10-01T23:59:59.000Z

    K{sub 2}CsSb is an attractive photocathode for high current applications. With a quantum efficiency of >4% at 532nm and >10% at 355nm, it is the only cathode to have demonstrated an average current of 35mA in an accelerator environment We describe ongoing cathode development work. for the energy recovery linac being constructed at BNL Several cathodes have been created on both copper and stainless steel substrates, and their spatial uniformity and spectral response have been characterized. Preliminary lifetime measurements have been performed at high average current densities (>1 mA/mm{sup 2}).

  1. Ultrafast terahertz-induced response of GeSbTe phase-change materials Michael J. Shu,1,2,a)

    E-Print Network [OSTI]

    Ultrafast terahertz-induced response of GeSbTe phase-change materials Michael J. Shu,1,2,a) Peter-optically, pumping with single-cycle terahertz pulses as a means of biasing phase-change materials on a sub of these materials is important for predicting the field-driven heating and phase-change behavior. However

  2. SB 4 Well Stimulation Treatment Regulations Text of Proposed Regulations

    E-Print Network [OSTI]

    surveys; routine activities that do not affect the integrity of the well or the formation; the removal SB 4 Well Stimulation Treatment Regulations Text of Proposed Regulations Page 1 of 13 SB 4 WELL STIMULATION TREATMENT REGULATIONS TEXT OF PROPOSED REGULATIONS Added text is shown in underline

  3. Transition threshold in Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses

    SciTech Connect (OSTI)

    Wei, Wen-Hou [Department of Applied Physics, Chongqing University, Chongqing 401331 (China); Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Fang, Liang, E-mail: lfang@cqu.edu.cn [Department of Applied Physics, Chongqing University, Chongqing 401331 (China); Shen, Xiang [Laboratory of Infrared Material and Devices, Advanced Technology Research Institute, Ningbo University, Ningbo 315211 (China); Wang, Rong-Ping [Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)

    2014-03-21T23:59:59.000Z

    Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses with Ge content from 7.5 to 32.5?at.?% have been prepared by melt-quench technique, and the physical parameters including glass transition temperature (T{sub g}), density (?), compactness (C), shear elastic moduli (C{sub s}), compression elastic moduli (C{sub c}), refractive index (n), and optical bandgap (E{sub g}) have been investigated. While all these physical parameters show threshold behavior in the glass with a chemically stoichiometric composition. Raman spectra analysis also indicates that, with increasing Ge content, Se-chains or rings gradually disappear until all Se-atoms are consumed in the glass with a chemically stoichiometric composition. With further increasing Ge content, homopolar Ge-Ge and Sb-Sb bonds are formed and the chemical order in the glasses is violated. The threshold behavior of the physical properties in the Ge{sub x}Sb{sub 10}Se{sub 90?x} glasses can be traced to demixing of networks above the chemically stoichiometric composition.

  4. Anisotropic giant magnetoresistance in NbSb?

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

    Wang, Kefeng [Brookhaven National Lab. (BNL), Upton, NY (United States); Graf, D. [Florida State Univ., Tallahassee, FL (United States); Li, Lijun [Brookhaven National Lab. (BNL), Upton, NY (United States); Wang, Limin [Brookhaven National Lab. (BNL), Upton, NY (United States); Petrovic, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-12-05T23:59:59.000Z

    We report large transverse magnetoreistance (the magnetoresistant ratio ~ 1.3 × 10?% in 2 K and 9 T field, and 4.3 × 10?% in 0.4 K and 32 T field, without saturation) and field-induced metal semiconductor-like transition in NbSb?. Magnetoresistance is significantly suppressed but the metal-semiconductor-like transition persists when the current is along the ac-plane. The sign reversal of the Hall resistivity and Seebeck coefficient in the field, plus the electronic structure reveal the coexistence of a small number of holes with very high mobility and a large number of electrons with low mobility. The large MR is attributed to the change of the Fermi surface induced by the magnetic field in addition to the high mobility metal.

  5. Anisotropic giant magnetoresistance in NbSb?

    SciTech Connect (OSTI)

    Wang, Kefeng [Brookhaven National Lab. (BNL), Upton, NY (United States); Graf, D. [Florida State Univ., Tallahassee, FL (United States); Li, Lijun [Brookhaven National Lab. (BNL), Upton, NY (United States); Wang, Limin [Brookhaven National Lab. (BNL), Upton, NY (United States); Petrovic, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-12-05T23:59:59.000Z

    We report large transverse magnetoreistance (the magnetoresistant ratio ~ 1.3 × 10?% in 2 K and 9 T field, and 4.3 × 10?% in 0.4 K and 32 T field, without saturation) and field-induced metal semiconductor-like transition in NbSb?. Magnetoresistance is significantly suppressed but the metal-semiconductor-like transition persists when the current is along the ac-plane. The sign reversal of the Hall resistivity and Seebeck coefficient in the field, plus the electronic structure reveal the coexistence of a small number of holes with very high mobility and a large number of electrons with low mobility. The large MR is attributed to the change of the Fermi surface induced by the magnetic field in addition to the high mobility metal.

  6. Anisotropic giant magnetoresistance in NbSb?

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

    Wang, Kefeng; Graf, D.; Li, Lijun; Wang, Limin; Petrovic, C.

    2014-12-05T23:59:59.000Z

    We report large transverse magnetoreistance (the magnetoresistant ratio ~ 1.3 × 10?% in 2 K and 9 T field, and 4.3 × 10?% in 0.4 K and 32 T field, without saturation) and field-induced metal semiconductor-like transition in NbSb?. Magnetoresistance is significantly suppressed but the metal-semiconductor-like transition persists when the current is along the ac-plane. The sign reversal of the Hall resistivity and Seebeck coefficient in the field, plus the electronic structure reveal the coexistence of a small number of holes with very high mobility and a large number of electrons with low mobility. The large MR is attributed tomore »the change of the Fermi surface induced by the magnetic field in addition to the high mobility metal.« less

  7. Manifestation of the Purcell effect in the conductivity of InAs/AlSb short-period superlattices

    SciTech Connect (OSTI)

    Kagan, M. S., E-mail: kagan@cplire.ru; Altukhov, I. V. [Russian Academy of Sciences, Kotel'nikov Institute of Radio Engineering and Electronics (Russian Federation)] [Russian Academy of Sciences, Kotel'nikov Institute of Radio Engineering and Electronics (Russian Federation); Baranov, A. N. [Universite Montpellier 2, Institute d'Electronique du Sud (France)] [Universite Montpellier 2, Institute d'Electronique du Sud (France); Il'inskaya, N. D. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Paprotskiy, S. K. [Russian Academy of Sciences, Kotel'nikov Institute of Radio Engineering and Electronics (Russian Federation)] [Russian Academy of Sciences, Kotel'nikov Institute of Radio Engineering and Electronics (Russian Federation); Teissier, R. [Universite Montpellier 2, Institute d'Electronique du Sud (France)] [Universite Montpellier 2, Institute d'Electronique du Sud (France); Usikova, A. A. [Russian Academy of Sciences, Kotel'nikov Institute of Radio Engineering and Electronics (Russian Federation)] [Russian Academy of Sciences, Kotel'nikov Institute of Radio Engineering and Electronics (Russian Federation)

    2013-11-15T23:59:59.000Z

    Vertical transport in short-period InAs/AlSb superlattices with type-II heterojunctions is studied at room temperature. It is found that negative differential conductivity appears in the miniband-conduction mode upon the overlapping of quantum-confined states in a periodic system of quantum wells. In the nonresonant-tunneling mode, equidistant peaks appear on the current-voltage characteristic of these superlattices. These peaks are attributed to the influence of the optical cavity on optical electron transitions in quantum wells (Purcell effect)

  8. Point defect balance in epitaxial GaSb

    SciTech Connect (OSTI)

    Segercrantz, N., E-mail: natalie.segercrantz@aalto.fi; Slotte, J.; Makkonen, I.; Kujala, J.; Tuomisto, F. [Department of Applied Physics, Aalto University, P.O. Box 14100, FIN-00076 Aalto Espoo (Finland); Song, Y.; Wang, S. [Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Göteborg (Sweden); State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences 865 Changning Road, Shanghai 200050 (China)

    2014-08-25T23:59:59.000Z

    Positron annihilation spectroscopy in both conventional and coincidence Doppler broadening mode is used for studying the effect of growth conditions on the point defect balance in GaSb:Bi epitaxial layers grown by molecular beam epitaxy. Positron annihilation characteristics in GaSb are also calculated using density functional theory and compared to experimental results. We conclude that while the main positron trapping defect in bulk samples is the Ga antisite, the Ga vacancy is the most prominent trap in the samples grown by molecular beam epitaxy. The results suggest that the p–type conductivity is caused by different defects in GaSb grown with different methods.

  9. Atmospheric Neutrinos

    E-Print Network [OSTI]

    Thomas K. Gaisser

    2006-12-11T23:59:59.000Z

    This paper is a brief overview of the theory and experimental data of atmospheric neutrino production at the fiftieth anniversary of the experimental discovery of neutrinos.

  10. Optical analyzer

    DOE Patents [OSTI]

    Hansen, A.D.

    1987-09-28T23:59:59.000Z

    An optical analyzer wherein a sample of particulate matter, and particularly of organic matter, which has been collected on a quartz fiber filter is placed in a combustion tube, and light from a light source is passed through the sample. The temperature of the sample is raised at a controlled rate and in a controlled atmosphere. The magnitude of the transmission of light through the sample is detected as the temperature is raised. A data processor, differentiator and a two pen recorder provide a chart of the optical transmission versus temperature and the rate of change of optical transmission versus temperature signatures (T and D) of the sample. These signatures provide information as to physical and chemical processes and a variety of quantitative and qualitative information about the sample. Additional information is obtained by repeating the run in different atmospheres and/or different rates or heating with other samples of the same particulate material collected on other filters. 7 figs.

  11. Selenization of Sb{sub 2}Se{sub 3} absorber layer: An efficient step to improve device performance of CdS/Sb{sub 2}Se{sub 3} solar cells

    SciTech Connect (OSTI)

    Leng, Meiying; Luo, Miao; Chen, Chao; Qin, Sikai; Chen, Jie; Zhong, Jie; Tang, Jiang, E-mail: jtang@mail.hust.edu.cn [Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology, Wuhan, 430074 Hubei (China); School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074 Hubei (China)

    2014-08-25T23:59:59.000Z

    Sb{sub 2}Se{sub 3} appeared as a very promising solar absorber because of their attractive material, optical and electrical properties. Previously, we reported thermal evaporated superstrate CdS/Sb{sub 2}Se{sub 3} solar cell achieving 1.9% efficiency. In this letter, we improved device performance to 3.7% (Voc?=?0.335?V, Jsc?=?24.4?mA/cm{sup 2}, and FF?=?46.8%) by an additional selenization step. Careful external quantum efficiency, capacitance-voltage profiling, and photoresponse study indicated selenization probably compensated selenium loss during thermal evaporation, reducing V{sub Se} associated recombination loss and improving device performance.

  12. Electronic-Structure of the Semimetals Bi and Sb

    E-Print Network [OSTI]

    LIU, Y.; Allen, Roland E.

    1995-01-01T23:59:59.000Z

    characteris- tic length, which makes Sb and Bi ideal for studying and employing quantum confinement effects. The three above semimetal-semiconductor superlattices are all grown in the [111] direction, along which the electron efFective masses of Bi and Sb... are relatively small and the quantum confinement length (scaling as m' ') consequently large. Also, there is only a small lattice mismatch in each case between the (111) planes of semimetal and semiconduc- tor. ' These three systems are, therefore...

  13. Measuring Nighttime Atmospheric Opacity Using Images From the Mars Exploration Rovers

    E-Print Network [OSTI]

    Bean, Keri M

    2012-07-11T23:59:59.000Z

    Atmospheric opacity, otherwise known as optical depth, is the measurement of the amount of radiation reaching the surface through the atmosphere. The spatial and temporal patterns in optical depth tell us about the aerosol and cloud cycles...

  14. Lattice Thermal conductivity of the Cu3SbSe4-Cu3SbS4 Solid Solution

    SciTech Connect (OSTI)

    Skoug, Eric [Michigan State University, East Lansing; Cain, Jeffrey D. [Michigan State University, East Lansing; Morelli, Donald [Michigan State University, East Lansing; Kirkham, Melanie J [ORNL; Majsztrik, Paul W [ORNL; Lara-Curzio, Edgar [ORNL

    2011-01-01T23:59:59.000Z

    The compositional dependence of the crystal structure and lattice thermal conductivity in the Cu3SbSe4-Cu3SbS4 system has been studied. The lattice parameters of the Cu3SbSe4-xSx compounds decrease linearly with x, and the tetragonal structure (space group no. 121) of the end compounds is maintained at all compositions. The thermal conductivity is much lower than that predicted by a simple rule of mixtures, which is typical for a solid solution. The Debye model produces a very reasonable fit to the experimental lattice thermal conductivity data when phonon scattering due to atomic mass and size differences between Se and S is taken into account. Compounds in this series are likely to improve upon the thermoelectric performance of Cu3SbSe4, which has shown ZT=0.72 when optimized.

  15. The antimony-group 11 chemical bond: Dissociation energies of the diatomic molecules CuSb, AgSb, and AuSb

    SciTech Connect (OSTI)

    Carta, V.; Ciccioli, A., E-mail: guido.gigli@uniroma1.it, E-mail: andrea.ciccioli@uniroma1.it; Gigli, G., E-mail: guido.gigli@uniroma1.it, E-mail: andrea.ciccioli@uniroma1.it [Dipartimento di Chimica, Sapienza Università di Roma, p.le A. Moro 5, 00185 Roma (Italy)

    2014-02-14T23:59:59.000Z

    The intermetallic molecules CuSb, AgSb, and AuSb were identified in the effusive molecular beam produced at high temperature under equilibrium conditions in a double-cell-like Knudsen source. Several gaseous equilibria involving these species were studied by mass spectrometry as a function of temperature in the overall range 1349–1822 K, and the strength of the chemical bond formed between antimony and the group 11 metals was for the first time measured deriving the following thermochemical dissociation energies (D{sub 0}{sup ?}, kJ/mol): 186.7 ± 5.1 (CuSb), 156.3 ± 4.9 (AgSb), 241.3 ± 5.8 (AuSb). The three species were also investigated computationally at the coupled cluster level with single, double, and noniterative quasiperturbative triple excitations (CCSD(T)). The spectroscopic parameters were calculated from the potential energy curves and the dissociation energies were evaluated at the Complete Basis Set limit, resulting in an overall good agreement with experimental values. An approximate evaluation of the spin-orbit effect was also performed. CCSD(T) calculations were further extended to the corresponding group 11 arsenide species which are here studied for the first time and the following dissociation energies (D{sub 0}{sup ?}, kJ/mol): 190 ± 10 (CuAs), 151 ± 10 (AgAs), 240 ± 15 (AuAs) are proposed. Taking advantage of the new experimental and computational information here presented, the bond energy trends along group 11 and 4th and 5th periods of the periodic table were analyzed and the bond energies of the diatomic species CuBi and AuBi, yet experimentally unobserved, were predicted on an empirical basis.

  16. atmospheric control systems: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  17. atmospheres psychiatric knowledge: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  18. atmospheric conditions influenced: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  19. atmospheric sulfate studies: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  20. atmospheric corrosion performance: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  1. atmosphere dosage spectrographique: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  2. atmospheric interference: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  3. accidental atmospheric release: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  4. atmosphere issledovanie zashchitnykh: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  5. atmospheric sampling glow: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  6. atmospheric presure arc: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  7. atmospheric temperature response: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  8. atmospheric nuclear bom: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  9. atmospheric control dosage: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  10. atmospheric sampling nouvelle: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  11. atmospheric phenomena: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  12. atmosphere combustion catalytique: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  13. atmosphere conditions-an interdisciplinary: Topics by E-print...

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  14. atmospheric corrosion behavior: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  15. atmospheric stagnation recirculation: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  16. atmospheric conditions controlling: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  17. atmosphere estudos termoanaliticos: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  18. atmospheric krypton-85 concentrations: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  19. atmospheric corrosivity maps: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  20. atmospheres inflammabilite du: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  1. atmospheric temperature: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  2. Effect of Solar Radiation on the Optical Properties and Molecular...

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

    Solar Radiation on the Optical Properties and Molecular Composition of Laboratory Proxies of Atmospheric Brown Carbon Effect of Solar Radiation on the Optical Properties and...

  3. SeZnSb alloy and its nano tubes, graphene composites properties

    SciTech Connect (OSTI)

    Singh, Abhay Kumar [Department of Physics, Indian Institute of Physics, Bangalore-560012 (India)

    2013-04-15T23:59:59.000Z

    Composite can alter the individual element physical property, could be useful to define the specific use of the material. Therefore, work demonstrates the synthesis of a new composition Se{sub 96}-Zn{sub 2}-Sb{sub 2} and its composites with 0.05% multi-walled carbon nano tubes and 0.05% bilayer graphene, in the glassy form. The diffused amorphous structure of the multi walled carbon nano tubes and bilayer gaphene in the Se{sub 96}-Zn{sub 2}-Sb{sub 2} alloy have been analyzed by using the Raman, X-ray photoluminescence spectroscopy, Furrier transmission infrared spectra, photoluminescence, UV/visible absorption spectroscopic measurements. The diffused prime Raman bands (G and D) have been appeared for the multi walled carbon nano tubes and graphene composites, while the X-ray photoluminescence core energy levels peak shifts have been observed for the composite materials. Subsequently the photoluminescence property at room temperature and a drastic enhancement (upto 80%) in infrared transmission percentage has been obtained for the bilayer graphene composite, along with optical energy band gaps for these materials have been evaluated 1.37, 1.39 and 1.41 eV.

  4. Interface effect of InSb quantum dots embedded in SiO{sub 2} matrix

    SciTech Connect (OSTI)

    Chen Dongliang; Fan Jiangwei; Wei Shiqiang [National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029 (China); Li Chaosheng; Zhu Zhengang [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, PO Box 1129, Hefei 230031 (China)

    2005-08-15T23:59:59.000Z

    The interface effect of InSb quantum dots (QDs) embedded in SiO{sub 2} matrix has been investigated by Raman scattering spectroscopy, x-ray diffraction (XRD), and x-ray absorption fine structure (both of EXAFS and XANES). The EXAFS and XRD results show clearly that the bond length of the Sb-In first shell of the InSb QDs contracts slightly about 0.02 A compared with that of the bulk InSb. The Raman scattering spectrum of the InSb QDs reveals that the lattice contraction partly weakens the phonon confinement effect. The coordination geometry at the interface of the InSb QDs is mainly Sb (In)-O covalent bridge bonds. The Sb K-XANES calculations of InSb QDs embedded in SiO{sub 2} matrix based on FEFF8 indicate that the intensity increase and the broadening of the white line peak of Sb atoms are essentially attributed to both the increase of Sb p-hole population and the change of Sb intra-atomic potential {mu}{sub 0}(E) affected by the SiO{sub 2} matrix. Our results show that the interface effect between the InSb QDs and the SiO{sub 2} matrix leads not only to the slight lattice contraction of InSb QDs and the large structural distortion in the interface area of InSb QDs, but also to the significant change of the Sb intra-atomic potential and the obvious charge redistribution around Sb atoms.

  5. Waveguide effect of GaAsSb quantum wells in a laser structure based on GaAs

    SciTech Connect (OSTI)

    Aleshkin, V. Ya. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)] [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Afonenko, A. A. [Belarussian State University (Belarus)] [Belarussian State University (Belarus); Dikareva, N. V. [Research Physical-Technical Institute of Nizhni Novgorod State University (Russian Federation)] [Research Physical-Technical Institute of Nizhni Novgorod State University (Russian Federation); Dubinov, A. A., E-mail: sanya@ipm.sci-nnov.ru; Kudryavtsev, K. E.; Morozov, S. V. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)] [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Nekorkin, S. M. [Research Physical-Technical Institute of Nizhni Novgorod State University (Russian Federation)] [Research Physical-Technical Institute of Nizhni Novgorod State University (Russian Federation)

    2013-11-15T23:59:59.000Z

    The waveguide effect of GaAsSb quantum wells in a semiconductor-laser structure based on GaAs is studied theoretically and experimentally. It is shown that quantum wells themselves can be used as waveguide layers in the laser structure. As the excitation-power density attains a value of 2 kW/cm{sup 2} at liquid-nitrogen temperature, superluminescence at the wavelength corresponding to the optical transition in bulk GaAs (at 835 nm) is observed.

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

    SciTech Connect (OSTI)

    Shu, Michael J. [Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Zalden, Peter [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Chen, Frank [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Weems, Ben [Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States); Chatzakis, Ioannis [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Xiong, Feng; Jeyasingh, Rakesh; Pop, Eric; Philip Wong, H.-S. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Hoffmann, Matthias C. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Wuttig, Matthias [I. Physikalisches Institut, RWTH Aachen University, 52056 Aachen (Germany); JARA–Fundamentals of Information Technology, RWTH Aachen University, 52056 Aachen (Germany); Lindenberg, Aaron M., E-mail: aaronl@stanford.edu [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States)

    2014-06-23T23:59:59.000Z

    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.

  7. Photocapacitance study of type-II GaSb/GaAs quantum ring solar cells

    SciTech Connect (OSTI)

    Wagener, M. C.; Botha, J. R. [Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Carrington, P. J.; Krier, A. [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)

    2014-01-07T23:59:59.000Z

    In this study, the density of states associated with the localization of holes in GaSb/GaAs quantum rings are determined by the energy selective charging of the quantum ring distribution. The authors show, using conventional photocapacitance measurements, that the excess charge accumulated within the type-II nanostructures increases with increasing excitation energies for photon energies above 0.9?eV. Optical excitation between the localized hole states and the conduction band is therefore not limited to the ?(k?=?0) point, with pseudo-monochromatic light charging all states lying within the photon energy selected. The energy distribution of the quantum ring states could consequently be accurately related from the excitation dependence of the integrated photocapacitance. The resulting band of localized hole states is shown to be well described by a narrow distribution centered 407?meV above the GaAs valence band maximum.

  8. Evaluation of the two-photon absorption characteristics of GaSb/GaAs quantum rings

    SciTech Connect (OSTI)

    Wagener, M. C.; Botha, J. R. [Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth 6031 (South Africa); Carrington, P. J. [Department of Electronic and Electrical Engineering, University College London, London (United Kingdom); Krier, A. [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)

    2014-07-28T23:59:59.000Z

    The optical parameters describing the sub-bandgap response of GaSb/GaAs quantum rings solar cells have been obtained from photocurrent measurements using a modulated pseudo-monochromatic light source in combination with a second, continuous photo-filling source. By controlling the charge state of the quantum rings, the photoemission cross-sections describing the two-photon sub-bandgap transitions could be determined independently. Temperature dependent photo-response measurements also revealed that the barrier for thermal hole emission from the quantum rings is significantly below the quantum ring localisation energy. The temperature dependence of the sub-bandgap photo-response of the solar cell is also described in terms of the photo- and thermal-emission characteristics of the quantum rings.

  9. Effect of Sb on the Properties of GaInP Top Cells (Presentation)

    SciTech Connect (OSTI)

    Olson, J. M.; McMahon, W. E.; Kurtz, S.

    2006-05-01T23:59:59.000Z

    The summary of this report is that: (1) Sb can be used to increase V{sub oc} of a GaInP top cell; (2) the photovoltaic quality of GaInP is relatively unaffected by the presence of Sb; and (3) Sb-doped GaInP/GaAs tandem cells show promise for achieving efficiencies over 32%.

  10. Atmospheric Aerosols Workshop | EMSL

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

    Atmospheric Aerosols Workshop Atmospheric Aerosols Workshop EMSL Science Theme Advisory Panel Workshop - Atmospheric Aerosol Chemistry, Climate Change, and Air Quality. Baer DR, BJ...

  11. Hydrogen passivation of Se and Te in AlSb M. D. McCluskey and E. E. Haller

    E-Print Network [OSTI]

    McCluskey, Matthew

    Hydrogen passivation of Se and Te in AlSb M. D. McCluskey and E. E. Haller Lawrence Berkeley observed local vibrational modes LVM's arising from DX-hydrogen complex in AlSb. Hydrogen was diffused into bulk AlSb:Se and AlSb:Te by annealing in sealed quartz ampoules with either hydrogen gas or methanol CH

  12. Influence of substituting Sn for Sb on the thermoelectric transport properties of CoSb{sub 3}-based skutterudites

    SciTech Connect (OSTI)

    Hui, Si [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Nielsen, Michele D. [Department of Mechanical and Aerospace Engineering, Ohio State University, Columbus, Ohio 43210 (United States); Homer, Mark R.; Medlin, Douglas L. [Sandia National Laboratories, Livermore, California 94550 (United States); Tobola, Janusz [AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, 30-059 Krakow (Poland); Salvador, James R. [Chemical and Materials Systems Laboratory, GM R and D Center, Warren, Michigan 48090 (United States); Heremans, Joseph P. [Department of Mechanical and Aerospace Engineering, Ohio State University, Columbus, Ohio 43210 (United States); Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Pipe, Kevin P. [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Uher, Ctirad [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-03-14T23:59:59.000Z

    Band structure calculations that incorporate impurity effects suggest that a band resonant state may be formed in p-type CoSb{sub 3}-based skutterudites by replacing Sb atoms with Sn dopant atoms. Such resonant states have the potential to greatly improve thermoelectric energy conversion efficiency by increasing the density of states variation near the Fermi level, thereby increasing the Seebeck coefficient at a given carrier concentration. Through transport measurements of the Seebeck coefficient, electrical conductivity, thermal conductivity, and Hall coefficient, we show that a practical band resonant state is not achieved by Sn doping. Compared to undoped CoSb{sub 3}, the dimensionless figure of merit (ZT) in Sn-doped CoSb{sub 3} is enhanced slightly at high temperatures to a value of 0.2, mostly due to a reduction in thermal conductivity. The Fermi level is calculated not to reach the band resonant state induced by Sn impurity atoms within the range of Sn concentrations examined here.

  13. Atmospheric Aerosol Systems | EMSL

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

    Science Themes Atmospheric Aerosol Systems Overview Atmospheric Aerosol Systems Biosystem Dynamics & Design Energy Materials & Processes Terrestrial & Subsurface Ecosystems...

  14. Thermal Processing Effects on Microstructure and Composition of Cu3SbSe3

    SciTech Connect (OSTI)

    Majsztrik, Paul W [ORNL; Kirkham, Melanie J [ORNL; Garcia Negron, Valerie [Polytechnic University of Puerto Rico (PUPR); Lara-Curzio, Edgar [ORNL; Skoug, Eric [Michigan State University, East Lansing; Morelli, Donald [Michigan State University, East Lansing

    2013-01-01T23:59:59.000Z

    We report on the effects of thermal processing on the microstructure and composition of a system with overall stoichiometry of 3Cu:1Sb:3Se with the aim of producing single-phase Cu3SbSe3. It was found that slowly cooling from the melt produced a multiphase material consisting of Cu2Se and CuSbSe2, but devoid of Cu3SbSe3. Cooling rapidly from the melt resulted in three-phase microstructures consisting of Cu2Se, CuSbSe2, and Cu3SbSe3. Subsequent annealing of the three-phase material between 325 C and 400 C shifted composition towards nearly pure Cu3SbSe3, the target compound of this work. The kinetics of the transformation into Cu3SbSe3 is successfully described using a modified Avrami model, which suggests that diffusion is the rate-controlling step. Values of Young s modulus and hardness, obtained by nanoindentation, are reported for Cu2Se, CuSbSe2, and Cu3SbSe3.

  15. GaSb substrates with extended IR wavelength for advanced space based applications

    SciTech Connect (OSTI)

    Allen, Lisa P.; Flint, Patrick; Dallas, Gordon; Bakken, Daniel; Blanchat, Kevin; Brown, Gail J.; Vangala, Shivashankar R.; Goodhue, William D.; Krishnaswami, Kannan

    2009-05-01T23:59:59.000Z

    GaSb substrates have advantages that make them attractive for implementation of a wide range of infrared (IR) detectors with higher operating temperatures for stealth and space based applications. A significant aspect that would enable widespread commercial application of GaSb wafers for very long wavelength IR (VLWIR) applications is the capability for transmissivity beyond 15 m. Due largely to the GaSb (antisite) defect and other point defects in undoped GaSb substrates, intrinsic GaSb is still slightly p-type and strongly absorbs in the VLWIR. This requires backside thinning of the GaSb substrate for IR transmissivity. An extremely low n-type GaSb substrate is preferred to eliminate thinning and provide a substrate solution for backside illuminated VLWIR devices. By providing a more homogeneous radial distribution of the melt solute to suppress GaSb formation and controlling the cooling rate, ultra low doped n:GaSb has been achieved. This study examines the surface properties and IR transmission spectra of ultra low doped GaSb substrates at both room and low temperatures. Atomic force microscopy (AFM), homoepitaxy by MBE, and infrared Fourier transform (FTIR) analysis was implemented to examine material quality. As compared with standard low doped GaSb, the ultra low doped substrates show over 50% transmission and consistent wavelength transparency past 23 m with improved %T at low temperature. Homoepitaxy and AFM results indicate the ultra low doped GaSb has a low thermal desorbtion character and qualified morphology. In summary, improvements in room temperature IR transmission and extended wavelength characteristics have been shown consistently for ultra low doped n:GaSb substrates.

  16. High performance photodiodes based on InAs/InAsSb type-II superlattices for very long wavelength infrared detection

    SciTech Connect (OSTI)

    Hoang, A. M.; Chen, G.; Chevallier, R.; Haddadi, A.; Razeghi, M., E-mail: razeghi@eecs.northwestern.edu [Center for Quantum Devices, Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, Illinois 60208 (United States)

    2014-06-23T23:59:59.000Z

    Very long wavelength infrared photodetectors based on InAs/InAsSb type-II superlattices are demonstrated on GaSb substrate. A heterostructure photodiode was grown with 50% cut-off wavelength of 14.6??m. At 77?K, the photodiode exhibited a peak responsivity of 4.8?A/W, corresponding to a quantum efficiency of 46% at ?300?mV bias voltage from front side illumination without antireflective coating. With the dark current density of 0.7?A/cm{sup 2}, it provided a specific detectivity of 1.4?×?10{sup 10} Jones. The device performance was investigated as a function of operating temperature, revealing a very stable optical response and a background limited performance below 50?K.

  17. Structural transition and amorphization in compressed ? - Sb 2 O 3

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

    Zhao, Zhao; Zeng, Qiaoshi; Zhang, Haijun; Wang, Shibing; Hirai, Shigeto; Zeng, Zhidan; Mao, Wendy L.

    2015-05-01T23:59:59.000Z

    Sb?O?-based materials are of broad interest in materials science and industry. High-pressure study using diamond anvil cells shows promise in obtaining new crystal and electronic structures different from their pristine states. Here, we conducted in situ angle dispersive synchrotron x-ray-diffraction and Raman spectroscopy experiments on ?-Sb?O? up to 50 GPa with neon as the pressure transmitting medium. A first-order structural transition was observed in between 15 and 20 GPa, where the cubic phase I gradually transformed into a layered tetragonal phase II through structural distortion and symmetry breaking. To explain the dramatic changes in sample color and transparency, we performed first-principles calculations to track the evolution of its density of states and electronic structure under pressure. At higher pressure, a sluggish amorphization was observed. Our results highlight the structural connections among the sesquioxides, where the lone electron pair plays an important role in determining the local structures.

  18. Comparative analysis of hole transport in compressively strained InSb and Ge quantum well heterostructures

    SciTech Connect (OSTI)

    Agrawal, Ashish; Barth, Michael; Madan, Himanshu; Datta, Suman [Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Lee, Yi-Jing; Lin, You-Ru; Wu, Cheng-Hsien; Ko, Chih-Hsin; Wann, Clement H. [Taiwan Semiconductor Manufacturing Company, Hsinchu 30078, Taiwan (China); Loubychev, Dmitri; Liu, Amy; Fastenau, Joel [IQE, Inc., Bethlehem, Pennsylvania 18015 (United States); Lindemuth, Jeff [Lake Shore Cryotronics, Westerville, Ohio 43082 (United States)

    2014-08-04T23:59:59.000Z

    Compressively strained InSb (s-InSb) and Ge (s-Ge) quantum well heterostructures are experimentally studied, with emphasis on understanding and comparing hole transport in these two-dimensional confined heterostructures. Magnetotransport measurements and bandstructure calculations indicate 2.5× lower effective mass for s-InSb compared to s-Ge quantum well at 1.9?×?10{sup 12}?cm{sup –2}. Advantage of strain-induced m* reduction is negated by higher phonon scattering, degrading hole transport at room temperature in s-InSb quantum well compared to s-Ge heterostructure. Consequently, effective injection velocity is superior in s-Ge compared to s-InSb. These results suggest s-Ge quantum well heterostructure is more favorable and promising p-channel candidate compared to s-InSb for future technology node.

  19. Photoemission study of the electronic structure and charge density waves of Na?Ti?Sb?O

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

    Tan, S. Y.; Jiang, J.; Ye, Z. R.; Niu, X. H.; Song, Y.; Zhang, C. L.; Dai, P. C.; Xie, B. P.; Lai, X. C.; Feng, D. L.

    2015-04-30T23:59:59.000Z

    The electronic structure of Na?Ti?Sb?O single crystal is studied by photon energy and polarization dependent angle-resolved photoemission spectroscopy (ARPES). The obtained band structure and Fermi surface agree well with the band structure calculation of Na?Ti?Sb?O in the non-magnetic state, which indicates that there is no magnetic order in Na?Ti?Sb?O and the electronic correlation is weak. Polarization dependent ARPES results suggest the multi-band and multi-orbital nature of Na?Ti?Sb?O. Photon energy dependent ARPES results suggest that the electronic structure of Na?Ti?Sb?O is rather two-dimensional. Moreover, we find a density wave energy gap forms below the transition temperature and reaches 65 meV atmore »7 K, indicating that Na?Ti?Sb?O is likely a weakly correlated CDW material in the strong electron-phonon interaction regime. (author)« less

  20. New Antimony Lanthanide Disulfide Dibromides LnSbS

    SciTech Connect (OSTI)

    Gout, D.; Jobic, S.; Evain, M.; Brec, R.

    2001-05-01T23:59:59.000Z

    CeSbS{sub 2}Br{sub 2} (I), Ce{sub 1/2}La{sub 1/2}SbS{sub 2}Br{sub 2} (II), and LaSbS{sub 2}Br{sub 2} (III) have been synthesized at 700 C from a mixture of LnBr{sub 3}, Ln{sub 2}S{sub 3}, Sb, and S and characterized by single-crystal X-ray diffraction. The three phases are isostructural (space group P2{sub 1}/c, Z=4) and crystallize in a novel, dense, bidimensional structure with cell parameters a=8.709(3) {angstrom}, b=9.187(2) {angstrom}, c=17.397(5) {angstrom} {beta}=104.26(3) for I, a=8.739(7) {angstrom}, b=9.219(7) {angstrom}, c=17.41(2) {angstrom}, =104.3(1) for II, and a=8.785(1) {angstrom}, b=9.236(2) {angstrom}, c=17.372(3) {angstrom}, {beta}=104.09(2) for III. In these compounds, [Ln S{sub 5}Br{sub 4}] and [Ln S{sub 3}Br{sub 6}] (Ln=Ce, La) distorted tricapped trigonal prisms define infinite {sub {infinity}}{sup 2}[LnS{sub 2}Br{sub 2}] layers counterbalanced and capped by antimony cations. In good accordance with the structural features, the charge balance in these materials is to be written Ln{sup III}Sb{sup III}S{sup -II}{sub 2}Br{sup -I}{sub 2}. These compounds exhibit a yellow hue with a measured absorption threshold of 2.42(1), 2.55(1), and 2.72(1) eV for I, II, and III, respectively. In the two cerium containing bromothioantimonates I and II, the origin of the color is assigned to a Ce-4f{yields}Ce-5d electronic transition, which shifts to higher energy from I to II due either to a matrix effect (increase of the mean Ln-S distances under the substitution of Ce for La) or to an atomic ordering between Ce and La cations on the Ln(1) and Ln(2) crystallographic sites. In contrast, the electronic transition at play in III involves a charge transfer from the bromine and sulfur ions to the antimony ions, the latter contributing substantially to the lowermost levels of the conduction band.

  1. INTRODUCTIONTOTHE SOLAR ATMOSPHERE

    E-Print Network [OSTI]

    ? #12;WHAT ISTHE SOLAR ATMOSPHERE? #12;#12;1-D MODEL ATMOSPHERE · Averaged over space and time · GoodINTRODUCTIONTOTHE SOLAR ATMOSPHERE D. Shaun Bloomfield Trinity College Dublin #12;OUTLINE · What is the solar atmosphere? · How is the solar atmosphere observed? · What structures exist and how do they evolve

  2. Mineral content analysis of atmospheric dust using hyperspectral information from space

    E-Print Network [OSTI]

    Kostinski, Alex

    Mineral content analysis of atmospheric dust using hyperspectral information from space A one of the world's largest sources of atmospheric mineral dust. Mineral composition optical properties, and mineral deposition to Amazon forests. In this study we examine hyperspectral

  3. Cu2Sb thin film electrodes prepared by pulsed laser deposition f or lithium batteries

    E-Print Network [OSTI]

    Song, Seung-Wan; Reade, Ronald P.; Cairns, Elton J.; Vaughey, Jack T.; Thackeray, Michael M.; Striebel, Kathryn A.

    2003-01-01T23:59:59.000Z

    The Electrochemical Society (Batteries and Energy ConversionDeposition for Lithium Batteries Seung-Wan Song, a, * Ronaldrechargeable lithium batteries. Introduction Sb-containing

  4. Page 1 MATH 262 Quiz 1 Name.- Sb 0“ PID: Sokve the problem ...

    E-Print Network [OSTI]

    MATH 262 Quiz 1. Name.- Sb 0“ PID: Sokve the problem systematicaìly and neatly und show aìl your work. (4pts) l. Find the equation of the orthogonal ...

  5. Cu2Sb thin film electrodes prepared by pulsed laser deposition f or lithium batteries

    E-Print Network [OSTI]

    Song, Seung-Wan; Reade, Ronald P.; Cairns, Elton J.; Vaughey, Jack T.; Thackeray, Michael M.; Striebel, Kathryn A.

    2003-01-01T23:59:59.000Z

    Laser Deposition for Lithium Batteries Seung-Wan Song, a, *in rechargeable lithium batteries. Introduction Sb-in rechargeable lithium batteries. Two advantages of

  6. All-optical Fog Sensor for Determining the Fog Visibility Range in Optical Wireless Communication Links

    E-Print Network [OSTI]

    Haddadi, Hamed

    All-optical Fog Sensor for Determining the Fog Visibility Range in Optical Wireless Communication is to use an all optical based fog sensor to study the atmospheric visibility of fog and its constituents on the optical wireless communication (OWC) links in a controlled laboratory test-bid. The fog sensor measures

  7. Direct imaging of InSb (110)-(1x1) surface grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Mishima, T. D. [Homer L. Dodge Department of Physics and Astronomy, and Center for Semiconductor Physics in Nanostructures, University of Oklahoma, Norman, Oklahoma 73019 (United States)

    2011-10-01T23:59:59.000Z

    High-resolution transmission electron microscopy under a profile imaging condition (HR-profile TEM) was employed to determine the structural model for the InSb(110)-(1x1) relaxation surface grown by molecular beam epitaxy (MBE). HR-profile TEM analyses indicate that the chevron model, which is widely accepted for zinc-blende-type III-V(110)-(1x1) surfaces prepared by cleavage, is also applicable to the InSb(110)-(1x1) surface prepared under an Sb-rich MBE condition. The assignment of atomic species (In or Sb) of InSb(110)-(1x1) surfaces was confirmed based on a HR-profile TEM image that captures the connected facets of InSb(110)-(1x1) and InSb(111)B-(2x2). On the basis of the well-known atomic species of InSb(111)B-(2x2), the atomic species of the InSb(110)-(1x1) surface were deduced straightforwardly: the atoms shifted upward and downward at the topmost layer of the InSb(110)-(1x1) surface are Sb and In, respectively. The atomic arrangements of the InSb(110)-(1x1)-InSb(111)B-(2x2) facet determined by HR-profile TEM may represent the atomic arrangements of zinc-blende-type III-V(331)B surfaces.

  8. atmosphere modules 1-3: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  9. atmosphere amap-nuuk west: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  10. atmospheric lead fall-out: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  11. atmospheric molecular cluster-ions: Topics by E-print Network

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

    to optical depth perturbations. In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular...

  12. Key results from SB8 simulant flowsheet studies

    SciTech Connect (OSTI)

    Koopman, D. C.

    2013-04-26T23:59:59.000Z

    Key technically reviewed results are presented here in support of the Defense Waste Processing Facility (DWPF) acceptance of Sludge Batch 8 (SB8). This report summarizes results from simulant flowsheet studies of the DWPF Chemical Process Cell (CPC). Results include: Hydrogen generation rate for the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) cycles of the CPC on a 6,000 gallon basis; Volume percent of nitrous oxide, N2O, produced during the SRAT cycle; Ammonium ion concentrations recovered from the SRAT and SME off-gas; and, Dried weight percent solids (insoluble, soluble, and total) measurements and density.

  13. Tank 40 Final SB7b Chemical Characterization Results

    SciTech Connect (OSTI)

    Bannochie, C. J.

    2012-11-06T23:59:59.000Z

    A sample of Sludge Batch 7b (SB7b) was taken from Tank 40 in order to obtain radionuclide inventory analyses necessary for compliance with the Waste Acceptance Product Specifications (WAPS). The SB7b WAPS sample was also analyzed for chemical composition including noble metals and fissile constituents. At the Savannah River National Laboratory (SRNL) the 3-L Tank 40 SB7b sample was transferred from the shipping container into a 4-L high density polyethylene bottle and solids were allowed to settle over the weekend. Supernate was then siphoned off and circulated through the shipping container to complete the transfer of the sample. Following thorough mixing of the 3-L sample, a 558 g sub-sample was removed. This sub-sample was then utilized for all subsequent analytical samples. Eight separate aliquots of the slurry were digested, four with HNO{sub 3}/HCl (aqua regia) in sealed Teflon? vessels and four with NaOH/Na{sub 2}O{sub 2} (alkali or peroxide fusion) using Zr crucibles. Two Analytical Reference Glass ? 1 (ARG-1) standards were digested along with a blank for each preparation. Each aqua regia digestion and blank was diluted to 1:100 mL with deionized water and submitted to Analytical Development (AD) for inductively coupled plasma ? atomic emission spectroscopy (ICP-AES) analysis, inductively coupled plasma ? mass spectrometry (ICP-MS) analysis, atomic absorption spectroscopy (AA) for As and Se, and cold vapor atomic absorption spectroscopy (CV-AA) for Hg. Equivalent dilutions of the alkali fusion digestions and blank were submitted to AD for ICP-AES analysis. Tank 40 SB7b supernate was collected from a mixed slurry sample in the SRNL Shielded Cells and submitted to AD for ICP-AES, ion chromatography (IC), total base/free OH{sup -}/other base, total inorganic carbon/total organic carbon (TIC/TOC) analyses, and Cs-137 gamma scan. Weighted dilutions of slurry were submitted for IC, TIC/TOC, and total base/free OH-/other base analyses. Activities for U-233, U-235, and Pu-239 were determined from the ICP-MS data for the aqua regia digestions of the Tank 40 WAPS slurry using the specific activity of each isotope. The Pu-241 value was determined from a Pu-238/-241 method.

  14. SB Electronics Breaks Ground on New Factory | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOrigin ofEnergy at Waste-to-Energy usingofRetrofittingFundA lSelectBuildingof328Report toSB

  15. atmospheric brown cloud: Topics by E-print Network

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

    I.; Burrows, Adam 2003-01-01 3 II. Black Carbon, Atmospheric Brown Clouds and Greenhouse Effect: Background CiteSeer Summary: satellite. The optical depth is a good index for...

  16. atmospheric black carbon: Topics by E-print Network

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

    Next Page Last Page Topic Index 1 II. Black Carbon, Atmospheric Brown Clouds and Greenhouse Effect: Background CiteSeer Summary: satellite. The optical depth is a good index for...

  17. atmospheric brown clouds: Topics by E-print Network

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

    I.; Burrows, Adam 2003-01-01 3 II. Black Carbon, Atmospheric Brown Clouds and Greenhouse Effect: Background CiteSeer Summary: satellite. The optical depth is a good index for...

  18. Superconductivity in Strong Spin Orbital Coupling Compound Sb2Se3

    E-Print Network [OSTI]

    Shen, Guoyin

    Superconductivity in Strong Spin Orbital Coupling Compound Sb2Se3 P. P. Kong1 , F. Sun1,3 , L. Y induce Sb2Se3 into a topological nontrivial state. Here, we report on the discovery of superconductivity superconductive at high pressures above 10 GPa proceeded by a pressure induced insulator to metal like transition

  19. ccsd00001219 Superconducting phase diagram of the lled skuterrudite PrOs 4 Sb 12

    E-Print Network [OSTI]

    ccsd­00001219 (version 2) : 16 Mar 2004 Superconducting phase diagram of the #12;lled skuterrudite a precise magnetic #12;eld-temperature superconducting phase diagram of PrOs4Sb12 down to 350 mK. We discuss the superconducting phase diagram of PrOs4Sb12 and its possible relation with an unconventional superconducting order

  20. The quantum efficiency of InGaAsSb thermophotovoltaic diodes

    SciTech Connect (OSTI)

    Martinelli, R.U.; Garbuzov, D.Z.; Lee, H.; Morris, N.; Odubanjo, T.; Taylor, G.C.; Connolly, J.C. [Sarnoff Corp., Princeton, NJ (United States)

    1997-10-01T23:59:59.000Z

    Uncoated InGaAsSb/GaSb thermophotovoltaic (TPV) diodes with 0.56 eV (2.2 {micro}m) bandgaps exhibit external quantum efficiencies of 59% at 2 {micro}m, which corresponds to an internal quantum efficiency of 95%. The structures were grown by molecular-beam epitaxy. The devices have electron diffusion lengths as long as 29 {micro}m in 8-{micro}m-wide p-InGaAsSb layers and hole diffusion lengths of 3 {micro}m in 6-{micro}m-wide n-InGaAsSb layers. The electron and hole diffusion lengths appear to increase with increasing p- and n-layer widths, respectively. These excellent minority carrier transport properties of InGaAsSb are well-suited to efficient TPV diode operation.

  1. Effect of annealing on the properties of Sb doped ZnO thin films prepared by spray pyrolysis technique

    SciTech Connect (OSTI)

    Kumar, N. Sadananda; Bangera, Kasturi V.; Shivakumar, G. K. [Thin Films Laboratory, Department of Physics, National Institute of Technology Karnataka,Surathkal - 575025, Mangalore (India)

    2014-01-28T23:59:59.000Z

    Sb doped ZnO thin films have been deposited on glass substrate at 450°C using spray pyrolysis technique. The X-ray diffraction studies revealed that the as deposited films are polycrystalline in nature with (100) preferred orientation. Whereas the films annealed at 450° C for 6h show a preferential orientation along (101) direction. Crystallites size varies from 15.7 nm to 34.95 nm with annealing duration. The Scanning electron microscopic analysis shows the plane and smooth surface of the films. The optical properties of annealed films have shown a variation in the band gap between 3.37 eV and 3.19 eV. Transparency of as grown and annealed films decreases from 78 % to 65% respectively in the visible region. The electrical conductivity of the as grown film shows an increase in the electrical conductivity by one order of magnitude with increase in the annealing duration.

  2. TEM Characterization of InAs/GaAs Quantum Dots Capped by a GaSb/GaAs Layer

    SciTech Connect (OSTI)

    Beltran, AM [Universidad de Cadiz, Spain; Ben, Teresa [Universidad de Cadiz, Spain; Sanchez, AM [Universidad de Cadiz, Spain; Sales Lerida, David [ORNL; Chisholm, Matthew F [ORNL; Varela del Arco, Maria [ORNL; Pennycook, Stephen J [ORNL; Galindo, Pedro [Universidad de Cadiz, Spain; Ripalda, JM [Instituto de Microelectronica de Madrid (CNM, CSIC); Molina Rubio, Sergio I [ORNL

    2008-01-01T23:59:59.000Z

    It is well known that there is intense interest in expanding the usable wavelength for electronic devices. This is one of the reasons to study new self-assembled semiconductor nanostructures. Telecommunication applications use InGaAsP/InP emitting at 1.3 and 1.55 m. Research efforts are dedicated to develop GaAs technology in order to achieve emission at the same range as InP, so GaAs could be used for optical fibre communications. Ga(As)Sb on InAs/GaAs quantum dots (QDs) is a promising nanostructure to be used in telecommunications. The introduction of antimony during or after the QDs growth is an effective solution to obtain a red shift in the emission wavelength, even at room temperature.

  3. Enhanced radiation resistant fiber optics

    DOE Patents [OSTI]

    Lyons, P.B.; Looney, L.D.

    1993-11-30T23:59:59.000Z

    A process for producing an optical fiber having enhanced radiation resistance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation. 4 figures.

  4. Enhanced radiation resistant fiber optics

    DOE Patents [OSTI]

    Lyons, Peter B. (Los Alamos, NM); Looney, Larry D. (Los Alamos, NM)

    1993-01-01T23:59:59.000Z

    A process for producing an optical fiber having enhanced radiation resitance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation.

  5. Band offsets determination and interfacial chemical properties of the Al2O3/GaSb system

    E-Print Network [OSTI]

    Yener, Aylin

    of a high quality dielectric/substrate interface. Native oxides of III­V com- pounds lead to the formation Sb is formed at the oxide/GaSb interface, which leads to a high leakage current.8 To overcome treatment. In contrast, NH4 2S and HCl solutions inhibit the Sb oxide formation. The lowest amount of Ga

  6. XRD, Electron Microscopy and Vibrational Spectroscopy Characterization of Simulated SB6 HLW Glasses - 13028

    SciTech Connect (OSTI)

    Stefanovsky, S.V. [SIA Radon, 7th Rostovskii lane 2/14, Moscow 119121 (Russian Federation) [SIA Radon, 7th Rostovskii lane 2/14, Moscow 119121 (Russian Federation); Institute of Physical Chemistry and Electrochemistry RAS, Leninskii av. 31, Moscow 119991 (Russian Federation); Nikonov, B.S.; Omelianenko, B.I. [Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry RAS, Staromonetniy lane 35, Moscow 100117 (Russian Federation)] [Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry RAS, Staromonetniy lane 35, Moscow 100117 (Russian Federation); Choi, A.; Marra, J.C. [Savannah River National Laboratory, Building 773A, Aiken 29808 (United States)] [Savannah River National Laboratory, Building 773A, Aiken 29808 (United States)

    2013-07-01T23:59:59.000Z

    Sample glasses have been made using SB6 high level waste (HLW) simulant (high in both Al and Fe) with 12 different frit compositions at a constant waste loading of 36 wt.%. As follows from X-ray diffraction (XRD) and optical and scanning electron microscopy (SEM) data, all the samples are composed of primarily glass and minor concentration of spinel phases which form both isometric grains and fine cubic (?1 ?m) crystals. Infrared spectroscopy (IR) spectra of all the glasses within the range of 400-1600 cm{sup -1} consist of the bands due to stretching and bending modes in silicon-oxygen, boron-oxygen, aluminum-oxygen and iron-oxygen structural groups. Raman spectra showed that for the spectra of all the glasses within the range of 850-1200 cm{sup -1} the best fit is achieved by suggestion of overlapping of three major components with maxima at 911-936 cm{sup -1}, 988-996 cm{sup -1} and 1020-1045 cm{sup -1}. The structural network is primarily composed of metasilicate chains and rings with embedded AlO{sub 4} and FeO{sub 4} tetrahedra. Major BO{sub 4} tetrahedra and BO{sub 3} triangles form complex borate units and are present as separate constituents. (authors)

  7. Microlensing Effects in Atmospheres of Substars

    E-Print Network [OSTI]

    L. A. Berdina; A. A. Minakov

    2007-12-10T23:59:59.000Z

    The purpose of the present work is the study of focusing properties of atmospheres of substars that is necessary for adequate interpreting of observational data and for solving the inverse problem consisting in recovery parameters of 'microlenses' (substars) and sources (quasars). Amplification factor for a quasar image as projected onto the field of microlenses-substars was computed for optical and radio wavelengths.

  8. Illinois SB 1987: the Clean Coal Portfolio Standard Law

    SciTech Connect (OSTI)

    NONE

    2009-01-15T23:59:59.000Z

    On January 12, 2009, Governor Rod Blagojevich signed SB 1987, the Clean Coal Portfolio Standard Law. The legislation establishes emission standards for new coal-fueled power plants power plants that use coal as their primary feedstock. From 2009-2015, new coal-fueled power plants must capture and store 50 percent of the carbon emissions that the facility would otherwise emit; from 2016-2017, 70 percent must be captured and stored; and after 2017, 90 percent must be captured and stored. SB 1987 also establishes a goal of having 25 percent of electricity used in the state to come from cost-effective coal-fueled power plants that capture and store carbon emissions by 2025. Illinois is the first state to establish a goal for producing electricity from coal-fueled power plants with carbon capture and storage (CCS). To support the commercial development of CCS technology, the legislation guarantees purchase agreements for the first Illinois coal facility with CCS technology, the Taylorville Energy Center (TEC); Illinois utilities are required to purchase at least 5 percent of their electricity supply from the TEC, provided that customer rates experience only modest increases. The TEC is expected to be completed in 2014 with the ability to capture and store at least 50 percent of its carbon emissions.

  9. aerosol optical thickness: Topics by E-print Network

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

    of solar radiation by atmospheric aerosols is a key el- ement of the Earth's radiative energy balance and climate. The optical properties of aerosol particles are, however,...

  10. adaptive optics parameters: Topics by E-print Network

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

    projects for large telescopes demand a proper knowledge of atmospheric turbulence to design efficient adaptive optics systems in order to reach large Strehl ratios. However, the...

  11. Nano-porosity in GaSb induced by swift heavy ion irradiation

    SciTech Connect (OSTI)

    Kluth, P., E-mail: patrick.kluth@anu.edu.au; Schnohr, C. S.; Giulian, R.; Araujo, L. L.; Lei, W.; Rodriguez, M. D.; Afra, B.; Bierschenk, T.; Ridgway, M. C. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia); Sullivan, J.; Weed, R. [ARC Centre for Antimatter-Matter Studies, AMPL, Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia); Li, W.; Ewing, R. C. [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan 48109-1005 (United States)

    2014-01-13T23:59:59.000Z

    Nano-porous structures form in GaSb after ion irradiation with 185 MeV Au ions. The porous layer formation is governed by the dominant electronic energy loss at this energy regime. The porous layer morphology differs significantly from that previously reported for low-energy, ion-irradiated GaSb. Prior to the onset of porosity, positron annihilation lifetime spectroscopy indicates the formation of small vacancy clusters in single ion impacts, while transmission electron microscopy reveals fragmentation of the GaSb into nanocrystallites embedded in an amorphous matrix. Following this fragmentation process, macroscopic porosity forms, presumably within the amorphous phase.

  12. Atmospheric Transport of Radionuclides

    SciTech Connect (OSTI)

    Crawford, T.V.

    2003-03-03T23:59:59.000Z

    The purpose of atmospheric transport and diffusion calculations is to provide estimates of concentration and surface deposition from routine and accidental releases of pollutants to the atmosphere. This paper discusses this topic.

  13. DWPF SIMULANT CPC STUDIES FOR SB7B

    SciTech Connect (OSTI)

    Koopman, D.

    2011-11-01T23:59:59.000Z

    Lab-scale DWPF simulations of Sludge Batch 7b (SB7b) processing were performed. Testing was performed at the Savannah River National Laboratory - Aiken County Technology Laboratory (SRNL-ACTL). The primary goal of the simulations was to define a likely operating window for acid stoichiometry for the DWPF Sludge Receipt and Adjustment Tank (SRAT). In addition, the testing established conditions for the SRNL Shielded Cells qualification simulation of SB7b-Tank 40 blend, supported validation of the current glass redox model, and validated the coupled process flowsheet at the nominal acid stoichiometry. An acid window of 105-140% by the Koopman minimum acid (KMA) equation (107-142% DWPF Hsu equation) worked for the sludge-only flowsheet. Nitrite was present in the SRAT product for the 105% KMA run at 366 mg/kg, while SME cycle hydrogen reached 94% of the DWPF Slurry Mix Evaporator (SME) cycle limit in the 140% KMA run. The window was determined for sludge with added caustic (0.28M additional base, or roughly 12,000 gallons 50% NaOH to 820,000 gallons waste slurry). A suitable processing window appears to be 107-130% DWPF acid equation for sludge-only processing allowing some conservatism for the mapping of lab-scale simulant data to full-scale real waste processing including potentially non-conservative noble metal and mercury concentrations. This window should be usable with or without the addition of up to 7,000 gallons of caustic to the batch. The window could potentially be wider if caustic is not added to SB7b. It is recommended that DWPF begin processing SB7b at 115% stoichiometry using the current DWPF equation. The factor could be increased if necessary, but changes should be made with caution and in small increments. DWPF should not concentrate past 48 wt.% total solids in the SME cycle if moderate hydrogen generation is occurring simultaneously. The coupled flowsheet simulation made more hydrogen in the SRAT and SME cycles than the sludge-only run with the same acid stoichiometric factor. The slow acid addition in MCU seemed to alter the reactions that consumed the small excess acid present such that hydrogen generation was promoted relative to sludge-only processing. The coupled test reached higher wt.% total solids, and this likely contributed to the SME cycle hydrogen limit being exceeded at 110% KMA. It is clear from the trends in the SME processing GC data, however, that the frit slurry formic acid contributed to driving the hydrogen generation rate above the SME cycle limit. Hydrogen generation rates after the second frit addition generally exceeded those after the first frit addition. SRAT formate loss increased with increasing acid stoichiometry (15% to 35%). A substantial nitrate gain which was observed to have occurred after acid addition (and nitrite destruction) was reversed to a net nitrate loss in runs with higher acid stoichiometry (nitrate in SRAT product less than sum of sludge nitrate and added nitric acid). Increased ammonium ion formation was also indicated in the runs with nitrate loss. Oxalate loss on the order 20% was indicated in three of the four acid stoichiometry runs and in the coupled flowsheet run. The minimum acid stoichiometry run had no indicated loss. The losses were of the same order as the official analytical uncertainty of the oxalate concentration measurement, but were not randomly distributed about zero loss, so some actual loss was likely occurring. Based on the entire set of SB7b test data, it is recommended that DWPF avoid concentrating additional sludge solids in single SRAT batches to limit the concentrations of noble metals to SB7a processing levels (on a grams noble metal per SRAT batch basis). It is also recommended that DWPF drop the formic acid addition that accompanies the process frit 418 additions, since SME cycle data showed considerable catalytic activity for hydrogen generation from this additional acid (about 5% increase in stoichiometry occurred from the frit formic acid). Frit 418 also does not appear to need formic acid addition to prevent gel formation in

  14. How atmospheric ice forms | EMSL

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

    atmospheric ice forms How atmospheric ice forms Released: September 08, 2014 New insights into atmospheric ice formation could improve climate models This study advances our...

  15. Atmospheric Pressure Reactor System | EMSL

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

    Atmospheric Pressure Reactor System Atmospheric Pressure Reactor System The atmospheric pressure reactor system is designed for testing the efficiency of various catalysts for the...

  16. The Effect of Condensates on the Characterization of Transiting Planet Atmospheres with Transmission Spectroscopy

    E-Print Network [OSTI]

    Jonathan J. Fortney

    2005-09-28T23:59:59.000Z

    Through a simple physical argument we show that the slant optical depth through the atmosphere of a "hot Jupiter" planet is 35-90 times greater than the normal optical depth. This not unexpected result has direct consequences for the method of transmission spectroscopy for characterizing the atmospheres of transiting giant planets. The atmospheres of these planets likely contain minor condensates and hazes which at normal viewing geometry have negligible optical depth, but at slant viewing geometry have appreciable optical depth that can obscure absorption features of gaseous atmospheric species. We identify several possible condensates. We predict that this is a general masking mechanism for all planets, not just for HD 209458b, and will lead to weaker than expected or undetected absorption features. Constraints on an atmosphere from transmission spectroscopy are not the same as constraints on an atmosphere at normal viewing geometry.

  17. Climate Sciences: Atmospheric Thermodynamics

    E-Print Network [OSTI]

    Russell, Lynn

    1 Climate Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http://aerosol.ucsd.edu/courses.html Text: Curry & Webster Atmospheric Thermodynamics Ch1 Composition Ch2 Laws Ch3 Transfers Ch12 Energy Climate Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http

  18. Time-course analysis of the Shewanella amazonensis SB2B proteome...

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

    the membrane fatty acid composition (due to induction of branched chain amino acid degradation pathways); however, we show this is not the case for SB2B. Although proteins and...

  19. Planning for sustainable communities: Regional incentives and local policy under SB375

    E-Print Network [OSTI]

    California at Davis, University of

    Planning for sustainable communities: Regional incentives and local policy under SB375 Gian Institute Policy for Energy, Environment and the Economy University of California, Davis March 19, 2014 impacts access density alternatives sustainability #12;Sustainable Communities Strategy (SCS) San Diego

  20. Controlling SEI Formation on SnSb-Porous Carbon Nanofibers for...

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

    for Improved Na Ion Storage. Abstract: Porous carbon nanofiber (CNF)-supported tin-antimony (SnSb) alloys is synthesized and applied as sodium ion battery anode. The...

  1. Terrestrial Planet Atmospheres. The Moon's Sodium Atmosphere

    E-Print Network [OSTI]

    Walter, Frederick M.

    ;Origins of Atmospheres · Outgassing ­ Volcanoes expel water, CO2, N2, H2S, SO2 removed by the Fme convecFon reaches deserts #12;Water and Ice Clouds #12;H2SO4

  2. Fiber optic fluid detector

    DOE Patents [OSTI]

    Angel, S.M.

    1987-02-27T23:59:59.000Z

    Particular gases or liquids are detected with a fiber optic element having a cladding or coating of a material which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses. 10 figs.

  3. Theoretical study of defect formation during the initial stages of native-oxide growth on GaSb (001)

    SciTech Connect (OSTI)

    Bermudez, V. M., E-mail: victor.bermudez@nrl.navy.mil [Electronics Science and Technology Division, U.S. Naval Research Laboratory, Washington, DC 20375 (United States)

    2014-04-07T23:59:59.000Z

    The formation of defects during the initial stages of native-oxide growth on the GaSb (001)-?(4?×?3) surface has been studied computationally using spin-unrestricted density functional theory. It is found that insertion into a Ga-Sb adatom dimer to form a peroxo Ga-O-O-Sb bridge is the most energetically favorable process with insertion into Ga-Sb back-bonds being somewhat less so. A Ga-O-O-Ga bridge between dimers is also favorable, but Sb-O-O-Sb bridges show little if any stability. In the course of analyzing molecular adsorption, a particularly reactive site has been identified that leads to O{sub 2} dissociation with little or no barrier. This process is initiated in the vicinity of an Sb-Sb dimer in the terminating layer and leads to sub-surface Ga and Sb defect sites (i.e., coordinatively unsaturated atoms) and to strained Ga-Sb bonds that may be susceptible to further O{sub 2} attack. However, the defects formed in these reactions do not produce states in the gap.

  4. GaAsSb-based heterojunction tunnel diodes for tandem solar cell interconnects

    SciTech Connect (OSTI)

    Zolper, J.C.; Klem, J.F.; Plut, T.A.; Tigges, C.P.

    1995-01-01T23:59:59.000Z

    We report a new approach to tunnel junctions that employs a pseudomorphic GaAsSb layer to obtain a band alignment at a InGaAs or InAlAs p-n junction favorable for forward bias tunneling. Since the majority of the band offset between GaAsSb and InGaAs or InAlAs is in the valence band, when an GaAsSb layer is placed at an InGaAs or InAlAs p-n junction the tunneling distance is reduced and the tunneling current is increased. For all doping levels studied, the presence of the GaAsSb-layer enhanced the forward tunneling characteristics. In fact, in a InGaAs/GaAsSb tunnel diode a peak tunneling current sufficient for a 1000 sun intercell interconnect was achieved with p = 1.5{times}l0{sup 18} cm{sup -3} while a similarly doped all-InGaAs diode was rectifying. This approach affords a new degree of freedom in designing tunnel junctions for tandem solar cell interconnects. Previously only doping levels could be varied to control the tunneling properties. Our approach relaxes the doping requirements by employing a GaAsSb-based heterojunction.

  5. Ab-Initio Determination of Novel Crystal Structures of the Thermoelectric Material MgAgSb

    SciTech Connect (OSTI)

    Kirkham, Melanie J [ORNL; Moreira Dos Santos, Antonio F [ORNL; Rawn, Claudia J [ORNL; Lara-Curzio, Edgar [ORNL; Sharp, Jeff W. [Marlow Industries, Inc; Thompson, Alan [Marlow Industries, Inc

    2012-01-01T23:59:59.000Z

    Materials with the half-Heusler structure possess interesting electrical and magnetic properties, including potential for thermoelectric applications. MgAgSb is compositionally and structurally related to many half-Heusler materials, but has not been extensively studied. This work presents the high-temperature X-ray diffraction analysis of MgAgSb between 27 and 420 C, complemented with thermoelectric property measurements. MgAgSb is found to exist in three different structures in this temperature region, taking the half-Heusler structure at high temperatures, a Cu2Sb-related structure at intermediate temperatures, and a previously unreported tetragonal structure at room temperature. All three structures are related by a distorted Mg-Sb rocksalt-type sublattice, differing primarily in the Ag location among the available tetrahedral sites. Transition temperatures between the three phases correlate well with discontinuities in the Seebeck coefficient and electrical conductivity; the best performance occurs with the novel room temperature phase. For application of MgAgSb as a thermoelectric material, it may be desirable to develop methods to stabilize the room temperature phase at higher temperatures.

  6. Optical Fibers Optics and Photonics

    E-Print Network [OSTI]

    Palffy-Muhoray, Peter

    Optical Fibers Optics and Photonics Dr. Palffy-Muhoray Ines Busuladzic Department of Theoretical and Applied Mathematics The University of Akron April 21, 2008 #12;Outline · History of optical fibers · What are optical fibers? · How are optical fibers made? · Light propagation through optical fibers · Application

  7. Magnetized Atmospheres around Accreting Neutron Stars

    E-Print Network [OSTI]

    S. Zane; R. Turolla; A. Treves

    2000-02-01T23:59:59.000Z

    We present a detailed investigation of atmospheres around accreting neutron stars with high magnetic field ($B\\gtrsim 10^{12}$ G) and low luminosity ($L\\lesssim 10^{33}$ erg/s). We compute the atmospheric structure, intensity and emergent spectrum for a plane-parallel, pure hydrogen medium by solving the transfer equations for the normal modes coupled to the hydrostatic and energy balance equations. The hard tail found in previous investigations for accreting, non-magnetic neutron stars with comparable luminosity is suppressed and the X-ray spectrum, although still harder than a blackbody at the star effective temperature, is nearly planckian in shape. Spectra from accreting atmospheres, both with high and low fields, are found to exhibit a significant excess at optical wavelengths above the Rayleigh-Jeans tail of the X-ray continuum.

  8. EMSL - Atmospheric Aerosol Systems

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

    scienceatmospheric The Atmospheric Aerosol Systems Science Theme focuses on understanding the chemistry, physics and molecular-scale dynamics of aerosols for model...

  9. Atmospheric Neutrino Fluxes

    E-Print Network [OSTI]

    Thomas K. Gaisser

    2005-02-18T23:59:59.000Z

    Starting with an historical review, I summarize the status of calculations of the flux of atmospheric neutrinos and how they compare to measurements.

  10. Density functional simulations of phase change materials: disordered phases of Ge8Sb2Te11 and Ag/In/Sb/Te alloys

    E-Print Network [OSTI]

    E*PCOS2009 Density functional simulations of phase change materials: disordered phases of Ge8Sb2Te75.0Te17.7 (AIST). These represent two families used widely as phase change materials: pseudobinary and more flexible than those of Ag. Key words: Phase change materials, density functional calculations

  11. Influence of GaAs surface termination on GaSb/GaAs quantum dot structure and band offsets

    SciTech Connect (OSTI)

    Zech, E. S.; Chang, A. S.; Martin, A. J.; Canniff, J. C.; Millunchick, J. M. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Lin, Y. H. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)] [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Goldman, R. S. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States) [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)

    2013-08-19T23:59:59.000Z

    We have investigated the influence of GaAs surface termination on the nanoscale structure and band offsets of GaSb/GaAs quantum dots (QDs) grown by molecular-beam epitaxy. Transmission electron microscopy reveals both coherent and semi-coherent clusters, as well as misfit dislocations, independent of surface termination. Cross-sectional scanning tunneling microscopy and spectroscopy reveal clustered GaSb QDs with type I band offsets at the GaSb/GaAs interfaces. We discuss the relative influences of strain and QD clustering on the band offsets at GaSb/GaAs interfaces.

  12. Recent progress in GaInAsSb thermophotovoltaics grown by organometallic vapor phase epitaxy

    SciTech Connect (OSTI)

    Wang, C.A.; Choi, H.K.; Oakley, D.C. [Massachusetts Inst. of Tech., Lexington, MA (United States). Lincoln Lab.; Charache, G.W. [Lockheed Martin, Inc., Schenectady, NY (United States)

    1998-06-01T23:59:59.000Z

    Studies on the materials development of Ga{sub 1{minus}x}In{sub x}As{sub y}Sb{sub 1{minus}y} alloys for thermophotovoltaic (TPV) devices are reviewed. Ga{sub 1{minus}x}In{sub x}As{sub y}Sb{sub 1{minus}y} epilayers were grown lattice matched to GaSb substrates by organometallic vapor phase epitaxy (OMVPE) using all organometallic precursors including triethylgallium, trimethylindium, tertiarybutylarsine, and trimethylantimony with diethyltellurium and dimethylzinc as the n- and p-type dopants, respectively. The overall material quality of these alloys depends on growth temperature, In content, V/III ratio, substrate misorientation, and to a lesser extent, growth rate. A mirror-like surface morphology and room temperature photoluminescence (PL) are obtained for GaInAsSb layers with peak emission in the wavelength range between 2 and 2.5 {micro}m. The crystal quality improves for growth temperature decreasing from 575 to 525 C, and with decreasing In content, as based on epilayer surface morphology and low temperature PL spectra. A trend of smaller full width at half-maximum for low temperature PL spectra is observed as the growth rate is increased from 1.5 to 2.5 and 5 {micro}m/h. In general, GaInAsSb layers grown on (100) GaSb substrates with a 6{degree} toward (111)B misorientation exhibited overall better material quality than layers grown on the more standard substrate (100)2{degree} toward (110). Consistent growth of high performance lattice-matched GaInAsSb TPV devices is also demonstrated.

  13. OMVPE growth and characterization of GaInAsSb for thermophotovoltaics

    SciTech Connect (OSTI)

    Wang, C.A.; Charache, G.W.

    1998-06-01T23:59:59.000Z

    Studies on the materials development of Ga{sub 1{minus}x}In{sub x}As{sub y}Sb{sub 1{minus}y} alloys for thermophotovoltaic (TPV) devices are reviewed. Ga{sub 1{minus}x}In{sub x}As{sub y}Sb{sub 1{minus}y} epilayers were grown lattice matched to GaSb substrates by organometallic vapor phase epitaxy (OMVPE) using all organometallic precursors including triethylgallium, trimethylindium, tertiarybutylarsine, and trimethylantimony with diethyltellurium and dimethylzinc as the n- and p-type dopants, respectively. The overall material quality of these alloys depends on growth temperature, In content, V/III ratio, substrate misorientation, and to a lesser extent, growth rate. A mirror-like surface morphology and room temperature photoluminescence (PL) are obtained for GaInAsSb layers with peak emission in the wavelength range between 2 and 2.5 {micro}m. The crystal quality improves for growth temperature decreasing from 575 to 525 C, and with decreasing In content, as based on epilayer surface morphology and low temperature PL spectra. A trend of smaller full width at half-maximum for low temperature PL spectra is observed as the growth rate is increased from 1.5 to 2.5 and 5 {micro}m/h. In general, GaInAsSb layers grown on (100) GaSb substrates with a 6{degree} toward (111)B misorientation exhibited overall better material quality than layers grown on the more standard substrate (100) 2{degree} toward (110). Consistent growth of high performance lattice-matched GaInAsSb TPV devices is also demonstrated.

  14. Synthesis, characterization and physical properties of the skutterudites Yb{sub x}Fe{sub 2}Ni{sub 2}Sb{sub 12} (0{<=}x{<=}0.4)

    SciTech Connect (OSTI)

    Kaltzoglou, Andreas; Vaqueiro, Paz [Department of Chemistry, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)] [Department of Chemistry, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Knight, Kevin S. [ISIS Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0OX (United Kingdom)] [ISIS Facility, Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0OX (United Kingdom); Powell, Anthony V., E-mail: a.v.powell@hw.ac.uk [Department of Chemistry, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

    2012-09-15T23:59:59.000Z

    The skutterudites Yb{sub x}Fe{sub 2}Ni{sub 2}Sb{sub 12} (0{<=}x{<=}0.4) have been prepared by solid-state reaction and characterised by powder X-ray diffraction. The compounds crystallise in the cubic space group Im3{sup Macron} (a Almost-Equal-To 9.1 A) with Yb atoms partially filling the voids in the skutterudite framework. A neutron time-of-flight diffraction experiment for Fe{sub 2}Ni{sub 2}Sb{sub 12} confirms the disorder of Fe and Ni atoms on the transition-metal site. Electrical resistivity, Seebeck coefficient and thermal conductivity measurements indicate that the thermoelectric performance of the skutterudites shows a marked dependence on the Yb content. Magnetic measurements over the temperature range 2{<=}T/K{<=}300 show paramagnetic behaviour for all compounds. Decomposition studies under an oxidising atmosphere at elevated temperatures have also been carried out by thermogravimetric analysis. - Graphical abstract: The filled skutterudites Yb{sub x}Fe{sub 2}Ni{sub 2}Sb{sub 12} have been prepared by solid-state reaction and characterised by powder X-ray diffraction. The thermoelectric performance depends strongly on the Yb content. The physical properties and thermal stability of the compounds are further discussed in comparison with the current state-of-the art thermoelectric skutterudites. Highlights: Black-Right-Pointing-Pointer A new series of skutterudites has been prepared and characterised. Black-Right-Pointing-Pointer Physical properties are affected by the degree of Yb filling. Black-Right-Pointing-Pointer The highest thermoelectric performance is found for Yb{sub 0.15}Fe{sub 2}Ni{sub 2}Sb{sub 12}. Black-Right-Pointing-Pointer The skutterudites decompose in air above 550 K.

  15. Atmospheric Dynamics II Instructor

    E-Print Network [OSTI]

    AT602 Atmospheric Dynamics II 2 credits Instructor: David W. J. Thompson davet: An Introduction to Dynamic Meteorology, 5th Edition, Academic Press (recommended) · Marshall, J., and Plumb, R. A., 2008: Atmosphere, Ocean, and Climate Dynamics: An Introductory Text, Academic Press. · Vallis, G. K

  16. Atmospheric Thermodynamics Composition

    E-Print Network [OSTI]

    Russell, Lynn

    1 Atmospheric Thermodynamics Ch1 Composition Ch2 Laws Ch3 Transfers Ch12 EnergyBalance Ch4 Water Ch Sciences: Atmospheric Thermodynamics Instructor: Lynn Russell, NH343 http #12;2 Review from Ch. 1 · Thermodynamic quantities · Composition · Pressure · Density · Temperature

  17. GaSb based ternary and quaternary diffused junction devices for TPV applications

    SciTech Connect (OSTI)

    Sundaram, V.S.; Saban, S.B.; Morgan, M.D.; Horne, W.E.; Evans, B.D.; Ketterl, J.R. [EDTEK Inc. 7082 S. 220th Street Kent, Washington 98032 (United States); Morosini, M.B.; Patel, N.B. [Instituto de Fisica, UNICAMP, Campinas, Brasil (Brazil); Field, H. [NREL, Golden, Colorado (United States)

    1997-03-01T23:59:59.000Z

    In this work we report the characteristics of ternary, GaInSb (Eg=0.70eV) and quarternary, GaInAsSb (Eg=0.5eV) diffused junction photovoltaic devices. The unique feature of the quarternary device is the extended long-wavelength response to 2.1 microns enabling the efficient use of the blackbody-like thermal sources operating at 1373 K in thermophotovoltaic energy conversion systems. The ternary device was fabricated by diffusing zinc into a n-type (100) oriented GaInSb substrate. For the quarternary, a four micron thick Te doped GaInAsSb layer grown by LPE on a n-type GaSb(100) wafer was used as the starting substrate for zinc diffusion. The ternary device exhibits an open circuit voltage of 0.38 V, Fill Factor of 0.63 and a short circuit current of 0.8A/cm{sup 2}, while the corresponding values for the quarternary device are 0.25 V, 0.58 and 0.8A/cm{sup 2}, respectively. The peak internal quantum efficiency for the ternary is over 90{percent} and that of the quarternary is above 75{percent}. Process optimization should improve the performance charcateristics of the quarternary. {copyright} {ital 1997 American Institute of Physics.}

  18. Habitability of waterworlds: runaway greenhouses, atmospheric expansion and multiple climate states of pure water atmospheres

    E-Print Network [OSTI]

    Goldblatt, Colin

    2015-01-01T23:59:59.000Z

    There are four different stable climate states for pure water atmospheres, as might exist on so-called "waterworlds". I map these as a function of solar constant for planets ranging in size from Mars size to 10 Earth-mass. The states are: globally ice covered (Tsnet absorption of sunlight. Across the range of planet sizes, I account for the atmospheres expanding to high altitudes as they warm. The emitting and absorbing surfaces (optical depth of unity) move to high altitude, making their area larger than the planet surfa...

  19. (GeTe){sub n}SbInTe{sub 3} (n?3)—Element distribution and thermal behavior

    SciTech Connect (OSTI)

    Fahrnbauer, Felix; Urban, Philipp; Welzmiller, Simon [Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststraße 20, 04275 Leipzig (Germany); Schröder, Thorsten; Rosenthal, Tobias [Department of Chemistry, Ludwig Maximilian University, Butenandtstraße 5-13, 81377 Munich (Germany); Oeckler, Oliver, E-mail: oliver.oeckler@gmx.de [Institute for Mineralogy, Crystallography and Materials Science, Leipzig University, Scharnhorststraße 20, 04275 Leipzig (Germany); Department of Chemistry, Ludwig Maximilian University, Butenandtstraße 5-13, 81377 Munich (Germany)

    2013-12-15T23:59:59.000Z

    Antimony in germanium antimony tellurides (GeTe){sub n}(Sb{sub 2}Te{sub 3}) can be substituted by indium. Homogeneous bulk samples of GeSbInTe{sub 4} (R3-bar m, Z=3, a=4.21324(5) Å, c=41.0348(10) Å) and Ge{sub 2}SbInTe{sub 5} (P3-bar m1, Z=1, a=4.20204(6) Å, c=17.2076(4) Å) were obtained; their structures were refined with the Rietveld method. Single-crystal X-ray diffraction using synchrotron radiation at the K edges of Sb and Te (exploiting anomalous dispersion) yields precise information on the element distribution in the trigonal layered structure of Ge{sub 3}SbInTe{sub 6} (R3-bar m, Z=3, a=4.19789(4) Å, c=62.1620(11) Å). The structure is characterized by van der Waals gaps between distorted rocksalt-type slabs of alternating cation and anion layers. The cation concentration is commensurately modulated with Sb preferring the positions near the gaps. In contrast to unsubstituted Ge{sub 3}Sb{sub 2}Te{sub 6}, quenching the NaCl-type high-temperature phase (stable above ?510 °C) easily yields a pseudocubic modification that is metastable at ambient conditions. Temperature-dependent powder diffraction reveals a broader stability range of the cubic high-temperature modification of Ge{sub 3}SbInTe{sub 6} compared to the ternary phases. In-containing samples partially decompose at ca. 300 °C but become homogeneous again when the high-temperature phase is formed. - Graphical abstract: Crystal structure of 33R-Ge{sub 3}SbInTe{sub 6} as determined by resonant X-ray diffraction, one example of the (GeTe){sub n}SbInTe{sub 3} series of compounds investigated. - Highlights: • The new compounds 21R-GeSbInTe{sub 4}, 9P-Ge{sub 2}SbInTe{sub 5} and 33R-Ge{sub 3}SbInTe are described. • The element distribution in 33R-Ge{sub 3}SbInTe{sub 6} was determined by resonant scattering. • The cation concentration in the crystal structure is strongly modulated. • The Sb substitution by In has a significant impact on phase transitions. • Results may be relevant for thermoelectrics and thin-film phase-change materials.

  20. INFERENCE OF INHOMOGENEOUS CLOUDS IN AN EXOPLANET ATMOSPHERE

    SciTech Connect (OSTI)

    Demory, Brice-Olivier; De Wit, Julien; Lewis, Nikole; Zsom, Andras; Seager, Sara [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)] [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Fortney, Jonathan [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)] [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Knutson, Heather; Desert, Jean-Michel [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States)] [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Heng, Kevin [Center for Space and Habitability, University of Bern, Sidlerstrasse 5, CH-3012, Bern (Switzerland)] [Center for Space and Habitability, University of Bern, Sidlerstrasse 5, CH-3012, Bern (Switzerland); Madhusudhan, Nikku [Department of Physics and Department of Astronomy, Yale University, New Haven, CT 06520 (United States)] [Department of Physics and Department of Astronomy, Yale University, New Haven, CT 06520 (United States); Gillon, Michael [Institut d'Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août, 17, Bat. B5C, B-4000 Liège 1 (Belgium)] [Institut d'Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août, 17, Bat. B5C, B-4000 Liège 1 (Belgium); Barclay, Thomas [NASA Ames Research Center, M/S 244-30, Moffett Field, CA 94035 (United States)] [NASA Ames Research Center, M/S 244-30, Moffett Field, CA 94035 (United States); Parmentier, Vivien [Laboratoire J.-L. Lagrange, UMR 7293, Université de Nice-Sophia Antipolis, CNRS, Observatoire de la Côte d'Azur B.P. 4229, F-06304 Nice Cedex 4 (France)] [Laboratoire J.-L. Lagrange, UMR 7293, Université de Nice-Sophia Antipolis, CNRS, Observatoire de la Côte d'Azur B.P. 4229, F-06304 Nice Cedex 4 (France); Cowan, Nicolas B., E-mail: demory@mit.edu [Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, F165, Evanston, IL 60208 (United States)

    2013-10-20T23:59:59.000Z

    We present new visible and infrared observations of the hot Jupiter Kepler-7b to determine its atmospheric properties. Our analysis allows us to (1) refine Kepler-7b's relatively large geometric albedo of Ag = 0.35 ± 0.02, (2) place upper limits on Kepler-7b thermal emission that remains undetected in both Spitzer bandpasses and (3) report a westward shift in the Kepler optical phase curve. We argue that Kepler-7b's visible flux cannot be due to thermal emission or Rayleigh scattering from H{sub 2} molecules. We therefore conclude that high altitude, optically reflective clouds located west from the substellar point are present in its atmosphere. We find that a silicate-based cloud composition is a possible candidate. Kepler-7b exhibits several properties that may make it particularly amenable to cloud formation in its upper atmosphere. These include a hot deep atmosphere that avoids a cloud cold trap, very low surface gravity to suppress cloud sedimentation, and a planetary equilibrium temperature in a range that allows for silicate clouds to potentially form in the visible atmosphere probed by Kepler. Our analysis does not only present evidence of optically thick clouds on Kepler-7b but also yields the first map of clouds in an exoplanet atmosphere.

  1. JOURNAL DE PHYSIQUE CoZZoque C8, supplgment au n08, Tome 42, aoGt 2980, page C8-519 ELECTRICAL RESISTIVITY AND THERMOELECTRIC POWER OF LIQUID Ge-Sb AND Pb-Sb ALLOYS

    E-Print Network [OSTI]

    Boyer, Edmond

    RESISTIVITY AND THERMOELECTRIC POWER OF LIQUID Ge-Sb AND Pb-Sb ALLOYS A. Bath, J.G. Gasser, J.L. Bretonnet, R Metz, France. Abstract.- The resistivity p and the thermoelectric power S have been measured experimental data on resistivi- ty and thermoelectric power (T.E.P.) for these two systems, and to discuss them

  2. Electron Scattering in InSb Quantum Wells due to Micro-twin Defects

    SciTech Connect (OSTI)

    Mishima, T. D.; Santos, M. B. [Homer L. Dodge Department of Physics and Astronomy, and Center for Semiconductor Physics in Nanostructure University of Oklahoma, 440 W. Brooks St., Norman, OK 73019 (United States)

    2011-12-26T23:59:59.000Z

    The transport electron scattering due to micro-twin (MT) defects in InSb quantum wells (QWs) has been investigated at room temperature (RT). A linear-regression-based scattering analysis showed that Matthiessen's rule is applicable to the RT electron mobility in 20-nm-thick InSb QWs that contain MTs (whose density is 5.6x10{sup 2}-1.2x10{sup 4} /cm) and threading dislocations (8.7x10{sup 8}-3.2x10{sup 9} /cm{sup 2}) as dominant structural defects. For such an InSb QW whose local electron mobility in its non-MT regions is 2.8x10{sup 4}-4.5x10{sup 4} cm{sup 2}/(Vs), the MT-originated energy barrier against the electron transport is deduced to be 0.081-0.093 eV at RT.

  3. Key experimental information on intermediate-range atomic structures in amorphous Ge2Sb2Te5 phase change material

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    .1063/1.3657139 Nature of phase transitions in crystalline and amorphous GeTe-Sb2Te3 phase change materials J. Chem. Phys on intermediate-range atomic structures in amorphous Ge2Sb2Te5 phase change material Shinya Hosokawa,1,2,a) Wolf change material Shinya Hosokawa, Wolf-Christian Pilgrim, Astrid Höhle, Daniel Szubrin, Nathalie Boudet

  4. Evaluation Of Glass Density To Support The Estimation Of Fissile Mass Loadings From Iron Concentrations In SB8 Glasses

    SciTech Connect (OSTI)

    Edwards, T. B.; Peeler, D. K.; Kot, W. K.; Gan, H.; Pegg, I. L.

    2013-04-30T23:59:59.000Z

    The Department of Energy – Savannah River (DOE-SR) has provided direction to Savannah River Remediation (SRR) to maintain fissile concentration in glass below 897 g/m{sup 3}. In support of that guidance, the Savannah River National Laboratory (SRNL) provided a technical basis and a supporting Microsoft® Excel® spreadsheet for the evaluation of fissile loading in Sludge Batch 5 (SB5), Sludge Batch 6 (SB6), Sludge Batch 7a (SB7a), and Sludge Batch 7b (SB7b) glass based on the iron (Fe) concentration in glass as determined by the measurements from the Slurry Mix Evaporator (SME) acceptability analysis. SRR has since requested that the necessary density information be provided to allow SRR to update the Excel® spreadsheet so that it may be used to maintain fissile concentration in glass below 897 g/m{sup 3} during the processing of Sludge Batch 8 (SB8). One of the primary inputs into the fissile loading spreadsheet includes an upper bound for the density of SB8-based glasses. Thus, these bounding density values are to be used to assess the fissile concentration in this glass system. It should be noted that no changes are needed to the underlying structure of the Excel-based spreadsheet to support fissile assessments for SB8. However, SRR should update the other key inputs to the spreadsheet that are based on fissile and Fe concentrations reported from the SB8 Waste Acceptance Product Specification (WAPS) sample.

  5. Electronic and structural response of InSb to ultra-short and ultra-intense laser pulses

    E-Print Network [OSTI]

    Burzo, Andrea Mihaela

    2001-01-01T23:59:59.000Z

    of the behavior of InSb following application of ultra-short and ultra-intense laser pulses. Motivated directly by these experiments, we have performed simulations of the electron-ion dynamics of InSb subjected to femtosecond-scale laser pulses. These simulations...

  6. ON AN ADAPTIVE CONTROL ALGORITHM FOR ADAPTIVE OPTICS APPLICATIONS

    E-Print Network [OSTI]

    ON AN ADAPTIVE CONTROL ALGORITHM FOR ADAPTIVE OPTICS APPLICATIONS MOODY T. CHU Abstract. The wavefront aberrations induced by atmospheric turbulence can severely degrade the performance of an optical imaging system. Adaptive optics refers to the process of removing unwanted wave front distortions

  7. ON AN ADAPTIVE CONTROL ALGORITHM FOR ADAPTIVE OPTICS APPLICATIONS

    E-Print Network [OSTI]

    ON AN ADAPTIVE CONTROL ALGORITHM FOR ADAPTIVE OPTICS APPLICATIONS MOODY T. CHU \\Lambda Abstract. The wavefront aberrations induced by atmospheric turbulence can severely degrade the performance of an optical imaging system. Adaptive optics refers to the process of removing unwanted wave front distortions

  8. Development of Bi-Sb-Te ternary alloy with compositionally graded structure

    SciTech Connect (OSTI)

    Yamamoto, A.; Ohta, T.

    1997-07-01T23:59:59.000Z

    Compositionally graded p-type Bi-Sb-Te thermoelectric material was synthesized by PIES (Pulverized and Intermixed Elements Sintering) method. The materials consisted of three segmented regions of different alloy composition, i.e., y = 0.8/0.825/0.9 in (Bi{sub 2}Te{sub 3}){sub 1{minus}y} (Sb{sub 2}Te{sub 3}){sub y} system. It was found that the electrical power output of the compositionally graded material was larger than that of the best single composition material when the temperature difference was the designed value.

  9. Prospects of nanostructures Bi{sub 1-x}Sb{sub x} for thermoelectricity

    SciTech Connect (OSTI)

    Nikolaeva, Albina A., E-mail: A.Nikolaeva@nano.asm.md [Gitsu Institute of Electronic Engineering and Nanotechnologies, Academiei 3/3, MD-2028, Chisinau, Republic of Moldova (Moldova, Republic of); International Laboratory of High Magnetic Fields and Low Temperatures, Wroclaw (Poland); Konopko, Leonid A. [Gitsu Institute of Electronic Engineering and Nanotechnologies, Academiei 3/3, MD-2028, Chisinau, Republic of Moldova (Moldova, Republic of) [Gitsu Institute of Electronic Engineering and Nanotechnologies, Academiei 3/3, MD-2028, Chisinau, Republic of Moldova (Moldova, Republic of); International Laboratory of High Magnetic Fields and Low Temperatures, Wroclaw (Poland); Huber, Tito E. [Department of Chemistry, Howard University, 500 College St. N.W., DC 20059, Washington (United States)] [Department of Chemistry, Howard University, 500 College St. N.W., DC 20059, Washington (United States); Bodiul, Pavel P.; Popov, Ivan A. [Gitsu Institute of Electronic Engineering and Nanotechnologies, Academiei 3/3, MD-2028, Chisinau, Republic of Moldova (Moldova, Republic of)] [Gitsu Institute of Electronic Engineering and Nanotechnologies, Academiei 3/3, MD-2028, Chisinau, Republic of Moldova (Moldova, Republic of)

    2012-09-15T23:59:59.000Z

    It has been predicted that surface states of topological insulators have large a thermopower and also ultrahigh mobilities. The authors report results of a magneto-thermoelectric investigation of single crystal Bi{sub 1-x}Sb{sub x} nanowires in a glass cover with diameters ranging from 90 nm to 5 {mu}m. The wide-ranging antimony concentration enabled us to study the effect of nanowire dimensionality in the semimetal, semi-conductor and gapless regimes. Quantum size effects in Bi-2 at%Sb nanowires, which are shown in temperature dependences of resistance R(T) and thermopower {alpha}(T) for the diameters significantly higher than the critical diameter for pure Bi-wires, are observed. The thermopower in weak magnetic fields, reaches values +400 {mu}V/K at T=20-40 K. Power factor {alpha}{sup 2}{sigma} depending on diameter of wires, structure, temperature and magnetic field is calculated. In connection with topological insulators, we will discuss the surface effect in the thermoelectric properties that we observe. - Graphical abstract: Temperature dependences of resistance R{sub T}/R{sub 300}(T) (a) for Bi-2 at%Sb wires various diameters d: 1-d=300 nm, 2-d=400 nm, 3-d=600 nm, 4-d=1600 nm. Inset (a) SEM cross sectional image of the 650 nm Bi-2 at%Sb wire (clear) in glass envelope (gray). The magnetic field dependences thermopower (H Double-Vertical-Line {Delta}T) (b) Bi-2 at%Sb wires, with different diameters: (1). d=300 nm, (2). d=400 nm, (3). d=600 nm, T=26 K. Highlights: Black-Right-Pointing-Pointer SMSC transition in semimetal Bi-Sb wires due to the quantum size effect is observed. Black-Right-Pointing-Pointer In Bi-6 at%Sb wires alloys has been realized the gapless (GL) state. Black-Right-Pointing-Pointer In the area GS state abnormal growth thermopower in magnetic fields is found out. Black-Right-Pointing-Pointer Semiconductor Bi{sub 1-x} Sb{sub x} nanowires manifest properties of the topological insulators.

  10. 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)

    2015-01-01T23:59:59.000Z

    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.

  11. Room-temperature mid-infrared “M”-type GaAsSb/InGaAs quantum well lasers on InP substrate

    SciTech Connect (OSTI)

    Chang, Chia-Hao; Li, Zong-Lin; Pan, Chien-Hung; Lu, Hong-Ting; Lee, Chien-Ping; Lin, Sheng-Di, E-mail: sdlin@mail.nctu.edu.tw [Department of Electronics Engineering, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan (China)

    2014-02-14T23:59:59.000Z

    We have demonstrated experimentally the InP-based “M”-type GaAsSb/InGaAs quantum-well (QW) laser lasing at 2.41??m at room temperature by optical pumping. The threshold power density per QW and extracted internal loss were about 234?W/cm{sup 2} and 20.5?cm{sup ?1}, respectively. The temperature-dependent photoluminescence (PL) and lasing spectra revealed interesting characteristics for this type of lasers. Two distinct regions in the temperature dependent threshold behavior were observed and the transition temperature was found to coincide with the cross over point of the PL and lasing emission peaks. The current-voltage characteristic of “M”-type QW laser was superior to the inverse “W”-type one due to its thinner barrier for holes. Further improvement of the “M”-type QW structure could lead to a cost-effective mid-infrared light source.

  12. Flat Plate PV Module Eligibility Listing Procedure Updated 6/2/14 Senate Bill 1 (SB1) defines the solar incentive programs for California, and flat plate PV

    E-Print Network [OSTI]

    Flat Plate PV Module Eligibility Listing Procedure Updated 6/2/14 Senate Bill 1 (SB1) defines the solar incentive programs for California, and flat plate PV modules 1 must be listed on the SB1 for adding PV modules to the SB1 list is as follows: 1 . Data submitted to the Energy Commission

  13. Frit Development Efforts for Sludge Batch 4 (SB4): Operating Window Assessments fo Scenarios Leading Up to the Selected Preparation Plan for SB4

    SciTech Connect (OSTI)

    Peeler, D

    2006-03-21T23:59:59.000Z

    The objective of this report is to document technical information that has been provided to Defense Waste Processing Facility (DWPF) and Closure Business Unit (CBU) personnel as part of the frit development support for Sludge Batch 4 (SB4). The information presented in this report includes projected operating windows (expressed in terms of waste loading) for various sludge blending and/or washing options coupled with candidate frits of interest. Although the Nominal Stage assessment serves as the primary tool for these evaluations, select systems were also evaluated using a Variation Stage assessment in which compositional variations were introduced. In addition, assessments of the impacts of nepheline formation potential and the SO{sub 4}{sup -} solubility limit on the projected operating windows are also provided. Although this information was used as part of the technical basis leading to CBU's development of the preferred SB4 preparation plan, none of the options presented in this report was selected as the preferred plan. Therefore, the information is presented without significant interpretation of the resulting operating windows, but the projected windows are provided so additional insight can be explored if desired. Detailed assessments of the projected operating windows (using both Nominal and Variation Stage assessments) of the preferred sludge preparation plan with candidate frits are to be documented elsewhere. The information provided in this report is focused solely on model-based projections of the operating windows for various SB4 blending strategies of interest. Although nepheline formation potential is monitored via model predictions as a part of this assessment, experimental work investigating the impact of nepheline on glass quality is also being addressed in a parallel study. The results of this paper study and the experimental assessments of melt rate, SO{sub 4} solubility, and/or nepheline formation potential are all critical components of the inputs into the frit selection process for SB4.

  14. Atmospheric Science: An introductory survey 1. Introduction to the atmosphere

    E-Print Network [OSTI]

    Folkins, Ian

    Sound Convergence Zone #12;Terrain effects #12;Von Karman vortex streets #12;Atmosphere in Earth system

  15. Modeling Space-Time Dynamics of Aerosols Using Satellite Data and Atmospheric Transport Model Output

    E-Print Network [OSTI]

    Shi, Tao

    Modeling Space-Time Dynamics of Aerosols Using Satellite Data and Atmospheric Transport Model of aerosol optical depth across mainland Southeast Asia. We include a cross validation study to assess

  16. 156 | Triennial Scientific Report ADAGUC Atmospheric Data Access for the Geospatial User Community

    E-Print Network [OSTI]

    Stoffelen, Ad

    Advanced Very High Resolution Radiometer BBC British Broadcasting Company BJEPB Beijing Environmental Radiometer AOGCM Atmosphere-Ocean General Circulation Model AOT Aerosol Optical Thickness API Application Potential Energy CERC Cambridge Environmental Research Consultants CESAR Cabauw Experimental Site

  17. 2254 IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 42, NO. 10, OCTOBER 2004 Retrieval of Semitransparent Ice Cloud Optical

    E-Print Network [OSTI]

    Li, Jun

    of Semitransparent Ice Cloud Optical Thickness From Atmospheric Infrared Sounder (AIRS) Measurements Heli Wei, Ping Abstract--An approach is developed to infer the optical thick- ness of semitransparent ice clouds (when optical thickness is less than 5) from Atmospheric Infrared Sounder (AIRS) high spectral resolution

  18. 0.52eV Quaternary InGaAsSb Thermophotovoltaic Diode Technology

    SciTech Connect (OSTI)

    MW Dashiell; JF Beausang; G Nichols; DM Depoy; LR Danielson; H Ehsani; KD Rahner; J Azarkevich; P Talamo; E Brown; S Burger; P Fourspring; W Topper; PF Baldasaro; CA Wang; R Huang; M Connors; G Turner; Z Shellenbarger; G Taylor; Jizhong Li; R Marinelli; D Donetski; S Anikeev; G Belenky; S Luryi; DR Taylor; J Hazel

    2004-06-09T23:59:59.000Z

    Thermophotovoltaic (TPV) diodes fabricated from 0.52eV lattice-matched InGaAsSb alloys are grown by Metal Organic Vapor Phase Epitaxy (MOVPE) on GaSb substrates. 4cm{sup 2} multi-chip diode modules with front-surface spectral filters were tested in a vacuum cavity and attained measured efficiency and power density of 19% and 0.58 W/cm{sup 2} respectively at operating at temperatures of T{sub radiator} = 950 C and T{sub diode} = 27 C. Device modeling and minority carrier lifetime measurements of double heterostructure lifetime specimens indicate that diode conversion efficiency is limited predominantly by interface recombination and photon energy loss to the GaSb substrate and back ohmic contact. Recent improvements to the diode include lattice-matched p-type AlGaAsSb passivating layers with interface recombination velocities less than 100 cm/s and new processing techniques enabling thinned substrates and back surface reflectors. Modeling predictions of these improvements to the diode architecture indicate that conversion efficiencies from 27-30% and {approx}0.85 W/cm{sup 2} could be attained under the above operating temperatures.

  19. Template Synthesis of Hollow Sb Nanoparticles as a High-Performance Lithium Battery Anode Material

    E-Print Network [OSTI]

    Cho, Jaephil

    Template Synthesis of Hollow Sb Nanoparticles as a High-Performance Lithium Battery Anode Material­14 the use of metal and carbon composites,15­20 and the introduction of nano- sized metals,21­25 have been reported. Studies involving hollow lithium reactive metal, however, have yet to be reported, although

  20. Engineering Sciences SB ESE Track Rev. July 2014 1/6

    E-Print Network [OSTI]

    Chou, James

    b or 21a) AM 101 ­ Statistical Inference for Scientists & Engineers ES 150 ­ Intro to Probability with Engineering Applications Statistics 110 ­ Introduction to Probability 1.0 _______ Applied Mathematics (1halfEngineering Sciences SB ­ ESE Track Rev. July 2014 1/6 Plan of Study for the Environmental Science

  1. Grain refinement and texture development of cast bi90sb10 alloy via severe plastic deformation

    E-Print Network [OSTI]

    Im, Jae-taek

    2009-05-15T23:59:59.000Z

    The purpose of this work was to study learn about grain refinement mechanisms and texture development in cast n-type Bi90Sb10 alloy caused by severe plastic deformation. The practical objective is to produce a fine grained and textured...

  2. Superconductivity in Topological Insulator Sb2Te3 Induced by Pressure

    E-Print Network [OSTI]

    Wang, Wei Hua

    Superconductivity in Topological Insulator Sb2Te3 Induced by Pressure J. Zhu1 *, J. L. Zhang1 *, P superconductivity and topology nature. A s new states of quantum matter, topological insulators are characterized to topological insulators, topological superconductors are expected to have a full pairing gap in the bulk

  3. Defining Good Infill A Convening Report on SB 226 and the California

    E-Print Network [OSTI]

    Kammen, Daniel M.

    with the facilitation of the discussion and presented their draft regulations for feedback. This report provides a brief) and SB 375 (Steinberg), state planning priorities, water conservation and energy efficiency standards, the performance standards include requirements that residential and commercial projects meet or exceed specified

  4. High resolution InSb quantum well ballistic nanosensors for room temperature applications

    SciTech Connect (OSTI)

    Gilbertson, Adam; Cohen, L. F. [Blackett Laboratory, Imperial College London, SW7 2BZ (United Kingdom); Lambert, C. J. [Department of Physics, Lancaster University, Lancaster, LA1 4YB (United Kingdom); Solin, S. A. [Department of Physics, Washington University in St. Louis, St. Louis, Missouri 63130 (United States)

    2013-12-04T23:59:59.000Z

    We report the room temperature operation of a quasi-ballistic InSb quantum well Hall sensor that exhibits a high frequency sensitivity of 560nT/?Hz at 20uA bias current. The device utilizes a partitioned buffer layer design that suppresses leakage currents through the mesa floor and can sustain large current densities.

  5. Optical Turbulence Characterization at LAMOST Site: Observations and Models

    E-Print Network [OSTI]

    Liu, L -Y; Yao, Y -Q; Vernin, J; Chadid, M; Wang, H -S; Yin, J; Wang, Y -P

    2015-01-01T23:59:59.000Z

    Atmospheric optical turbulence seriously limits the performance of high angular resolution instruments. An 8-night campaign of measurements was carried out at the LAMOST site in 2011, to characterize the optical turbulence. Two instruments were set up during the campaign: a Differential Image Motion Monitor (DIMM) used to measure the total atmospheric seeing, and a Single Star Scidar (SSS) to measure the vertical profiles of the turbulence C_n^2(h) and the horizontal wind velocity V(h). The optical turbulence parameters are also calculated with the Weather Research and Forecasting (WRF) model coupled with the Trinquet-Vernin model, which describes optical effects of atmospheric turbulence by using the local meteorological parameters. This paper presents assessment of the optical parameters involved in high angular resolution astronomy. Its includes seeing, isoplanatic angle, coherence time, coherence etendue, vertical profiles of optical turbulence intensity _n^2(h)$ and horizontal wind speed V(h). The median...

  6. Atmospheric pressure helium afterglow discharge detector for gas chromatography

    DOE Patents [OSTI]

    Rice, Gary (Gloucester, VA); D'Silva, Arthur P. (Ames, IA); Fassel, Velmer A. (Ames, IA)

    1986-05-06T23:59:59.000Z

    An apparatus for providing a simple, low-frequency electrodeless discharge system for atmospheric pressure afterglow generation. A single quartz tube through which a gas mixture is passed is extended beyond a concentric electrode positioned thereabout. A grounding rod is placed directly above the tube outlet to permit optical viewing of the discharge between the electrodes.

  7. Atmospheric pressure helium afterglow discharge detector for gas chromatography

    DOE Patents [OSTI]

    Rice, G.; D'Silva, A.P.; Fassel, V.A.

    1985-04-05T23:59:59.000Z

    An apparatus for providing a simple, low-frequency, electrodeless discharge system for atmospheric pressure afterglow generation. A single quartz tube through which a gas mixture is passed is extended beyond a concentric electrode positioned thereabout. A grounding rod is placed directly above the tube outlet to permit optical viewing of the discharge between the electrodes.

  8. Improved detection of atmospheric turbulence with SLODAR

    E-Print Network [OSTI]

    Michael Goodwin; Charles Jenkins; Andrew Lambert

    2007-06-19T23:59:59.000Z

    We discuss several improvements in the detection of atmospheric turbulence using SLOpe Detection And Ranging (SLODAR). Frequently, SLODAR observations have shown strong ground-layer turbulence, which is beneficial to adaptive optics. We show that current methods which neglect atmospheric propagation effects can underestimate the strength of high altitude turbulence by up to ~ 30%. We show that mirror and dome seeing turbulence can be a significant fraction of measured ground-layer turbulence, some cases up to ~ 50%. We also demonstrate a novel technique to improve the nominal height resolution, by a factor of 3, called Generalized SLODAR. This can be applied when sampling high-altitude turbulence, where the nominal height resolution is the poorest, or for resolving details in the important ground-layer.

  9. Microstructure and conductance-slope of InAs/GaSb tunnel diodes

    SciTech Connect (OSTI)

    Iutzi, Ryan M., E-mail: iutzi@mit.edu; Fitzgerald, Eugene A. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2014-06-21T23:59:59.000Z

    InAs/GaSb and similar materials systems have generated great interest as a heterojunction for tunnel field effect transistors (TFETs) due to favorable band alignment. However, little is currently understood about how such TFETs are affected by materials defects and nonidealities. We present measurements of the conductance slope for various InAs/GaSb heterojunctions via two-terminal electrical measurements, which removes three-terminal parasitics and enables direct study on the effect of microstructure on tunnelling. Using this, we can predict how subthreshold swings in TFETs can depend on microstructure. We also demonstrate growth and electrical characterization for structures grown by metalorganic chemical vapor deposition (MOCVD)—a generally more scalable process compared with molecular beam epitaxy (MBE). We determine that misfit dislocations and point defects near the interface can lead to energy states in the band-gap and local band bending that result in trap-assisted leakage routes and nonuniform band alignment across the junction area that lower the steepness of the conductance slope. Despite the small lattice mismatch, misfit dislocations still form in InAs on GaSb due to relaxation as a result of large strain from intermixed compositions. This can be circumvented by growing GaSb on InAs, straining the GaSb underlayer, or lowering the InAs growth temperature in the region of the interface. The conductance slope can also be improved by annealing the samples at higher temperatures, which we believe acts to annihilate point defects and average out major fluctuations in band alignment across the interface. Using a combination of these techniques, we can greatly improve the steepness of the conductance slope which could result in steeper subthreshold swings in TFETs in the future.

  10. Highly mismatched N-rich GaN{sub 1-x}Sb{sub x} films grown by low temperature molecular beam epitaxy

    SciTech Connect (OSTI)

    Yu, K. M.; Walukiewicz, W. [Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)] [Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Sarney, W. L.; Svensson, S. P. [US Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783 (United States)] [US Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783 (United States); Novikov, S. V.; Foxon, C. T. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)] [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Detert, D.; Zhao, R. [Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States) [Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); Denlinger, J. D. [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)] [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Dubon, O. D. [Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States) [Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); US Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783 (United States)

    2013-03-11T23:59:59.000Z

    We have grown N-rich, dilute Sb GaN{sub 1-x}Sb{sub x} alloys by low temperature molecular beam epitaxy. At low growth temperature of <100 Degree-Sign C the material loses crystallinity and becomes primarily amorphous with small crystallites of 2-5 nm at a Sb composition of >4 at. %. Despite the different microstructures found for GaN{sub 1-x}Sb{sub x} alloys with different composition, the absorption edge shifts continuously from 3.4 eV (GaN) to close to 1 eV for samples with Sb content >30 at. %. GaN{sub 1-x}Sb{sub x} alloys with less than 5 at. % Sb show sufficient bandgap reduction ({approx}2 eV), making them suitable for photoelectrochemical applications.

  11. Optical humidity sensor

    DOE Patents [OSTI]

    Tarvin, J.A.

    1987-02-10T23:59:59.000Z

    An optical dielectric humidity sensor is disclosed which includes a dielectric mirror having multiple alternating layers of two porous water-adsorbent dielectric materials with differing indices of refraction carried by a translucent substrate. A narrow-band polarized light source is positioned to direct light energy onto the mirror, and detectors are positioned to receive light energy transmitted through and reflected by the mirror. A ratiometer indicates humidity in the atmosphere which surrounds the dielectric mirror as a function of a ratio of light energies incident on the detectors. 2 figs.

  12. Optical keyboard

    DOE Patents [OSTI]

    Veligdan, James T. (Manorville, NY); Feichtner, John D. (Fiddletown, CA); Phillips, Thomas E. (San Diego, CA)

    2001-01-01T23:59:59.000Z

    An optical keyboard includes an optical panel having optical waveguides stacked together. First ends of the waveguides define an inlet face, and opposite ends thereof define a screen. A projector transmits a light beam outbound through the waveguides for display on the screen as a keyboard image. A light sensor is optically aligned with the inlet face for sensing an inbound light beam channeled through the waveguides from the screen upon covering one key of the keyboard image.

  13. Adaptive Optics for Large Telescopes

    SciTech Connect (OSTI)

    Olivier, S

    2008-06-27T23:59:59.000Z

    The use of adaptive optics was originally conceived by astronomers seeking to correct the blurring of images made with large telescopes due to the effects of atmospheric turbulence. The basic idea is to use a device, a wave front corrector, to adjust the phase of light passing through an optical system, based on some measurement of the spatial variation of the phase transverse to the light propagation direction, using a wave front sensor. Although the original concept was intended for application to astronomical imaging, the technique can be more generally applied. For instance, adaptive optics systems have been used for several decades to correct for aberrations in high-power laser systems. At Lawrence Livermore National Laboratory (LLNL), the world's largest laser system, the National Ignition Facility, uses adaptive optics to correct for aberrations in each of the 192 beams, all of which must be precisely focused on a millimeter scale target in order to perform nuclear physics experiments.

  14. Dynamics of Atmospheres

    E-Print Network [OSTI]

    Read, Peter L.

    transfer ­ Solar heating of surface, and atmosphere via dust absorption ­ Infrared CO2 band cooling (especially around 667 cm-1) ­ nonLTE near-infrared heating of CO2 and nonLTE cooling effects above ~60-80 km. Baroclinic waves, scales, heat and momentum transport, seasonal occurrence. Qualitative treatment

  15. Laboratory for Atmospheric and

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    . Along with this growth came a new building on campus and a new name: the Laboratory for Atmospheric of the Sun to the outermost fringes of the solar system. With LASP's continuing operations role in the planet traditional and stable approach based on federal agency funding of research grant

  16. Temperature-dependent structural property and power factor of n type thermoelectric Bi{sub 0.90}Sb{sub 0.10} and Bi{sub 0.86}Sb{sub 0.14} alloys

    SciTech Connect (OSTI)

    Malik, K.; Das, Diptasikha [Department of Physics, University of Calcutta, 92 A P C Road, Kolkata 700 009 (India)] [Department of Physics, University of Calcutta, 92 A P C Road, Kolkata 700 009 (India); Bandyopadhyay, S.; Banerjee, Aritra, E-mail: arbphy@caluniv.ac.in [Department of Physics, University of Calcutta, 92 A P C Road, Kolkata 700 009 (India) [Department of Physics, University of Calcutta, 92 A P C Road, Kolkata 700 009 (India); Center for Research in Nanoscience and Nanotechnology, University of Calcutta, JD-2, Sector-III, Saltlake City, Kolkata 700 098 (India); Mandal, P.; Srihari, Velaga [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India)] [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India); Deb, A. K. [Department of Physics, Raiganj College (University College), Uttar Dinajpur 733 134 (India)] [Department of Physics, Raiganj College (University College), Uttar Dinajpur 733 134 (India)

    2013-12-09T23:59:59.000Z

    Thermal variation of structural property, linear thermal expansion coefficient (?), resistivity (?), thermopower (S), and power factor (PF) of polycrystalline Bi{sub 1-x}Sb{sub x} (x?=?0.10 and 0.14) samples are reported. Temperature-dependent powder diffraction experiments indicate that samples do not undergo any structural phase transition. Rietveld refinement technique has been used to perform detailed structural analysis. Temperature dependence of ? is found to be stronger for Bi{sub 0.90}Sb{sub 0.10}. Also, PF for direct band gap Bi{sub 0.90}Sb{sub 0.10} is higher as compared to that for indirect band gap Bi{sub 0.86}Sb{sub 0.14}. Role of electron-electron and electron-phonon scattering on ?, S, and PF has been discussed.

  17. SIO 217a Atmospheric and Climate Sciences I: Atmospheric Thermodynamics

    E-Print Network [OSTI]

    Russell, Lynn

    SIO 217a Atmospheric and Climate Sciences I: Atmospheric Thermodynamics Course Syllabus and Lecture Schedule Instructor: Lynn Russell, 343 NH, 534-4852, lmrussell@ucsd.edu Text: Thermodynamics of Atmospheres of Thermodynamics (Work, Heat, First Law, Second Law, Heat Capacity, Adiabatic Processes) 5-Oct F Hurricane Example

  18. Impact of stress relaxation in GaAsSb cladding layers on quantum dot creation in InAs/GaAsSb structures grown on GaAs (001)

    SciTech Connect (OSTI)

    Bremner, S. P. [School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052 (Australia)] [School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052 (Australia); Ban, K.-Y.; Faleev, N. N.; Honsberg, C. B. [School of Electrical, Computer and Energy Engineering, Ira A. Fulton Schools of Engineering, Solar Power Lab, Arizona State University, Tempe, Arizona 85287 (United States)] [School of Electrical, Computer and Energy Engineering, Ira A. Fulton Schools of Engineering, Solar Power Lab, Arizona State University, Tempe, Arizona 85287 (United States); Smith, D. J. [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States)] [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States)

    2013-09-14T23:59:59.000Z

    We describe InAs quantum dot creation in InAs/GaAsSb barrier structures grown on GaAs (001) wafers by molecular beam epitaxy. The structures consist of 20-nm-thick GaAsSb barrier layers with Sb content of 8%, 13%, 15%, 16%, and 37% enclosing 2 monolayers of self-assembled InAs quantum dots. Transmission electron microscopy and X-ray diffraction results indicate the onset of relaxation of the GaAsSb layers at around 15% Sb content with intersected 60° dislocation semi-loops, and edge segments created within the volume of the epitaxial structures. 38% relaxation of initial elastic stress is seen for 37% Sb content, accompanied by the creation of a dense net of dislocations. The degradation of In surface migration by these dislocation trenches is so severe that quantum dot formation is completely suppressed. The results highlight the importance of understanding defect formation during stress relaxation for quantum dot structures particularly those with larger numbers of InAs quantum-dot layers, such as those proposed for realizing an intermediate band material.

  19. Nanostructured Ge{sub 2}Sb{sub 2}Te{sub 5} chalcogenide films produced by laser electrodispersion

    SciTech Connect (OSTI)

    Yavsin, D. A., E-mail: yavsin@mail.ioffe.ru; Kozhevin, V. M.; Gurevich, S. A.; Yakovlev, S. A.; Melekh, B. T.; Yagovkina, M. A.; Pevtsov, A. B. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

    2014-12-15T23:59:59.000Z

    Amorphous nanostructured films of a complex chalcogenide (Ge{sub 2}Sb{sub 2}Te{sub 5}) are produced by laser electrodispersion and their structural and electrical properties are studied. It is found that the characteristic size of Ge{sub 2}Sb{sub 2}Te{sub 5} nanoparticles in the structure of the films is 1.5–5 nm.

  20. Pluto's Atmosphere Does Not Collapse

    E-Print Network [OSTI]

    Olkin, C B; Borncamp, D; Pickles, A; Sicardy, B; Assafin, M; Bianco, F B; Buie, M W; de Oliveira, A Dias; Gillon, M; French, R G; Gomes, A Ramos; Jehin, E; Morales, N; Opitom, C; Ortiz, J L; Maury, A; Norbury, M; Ribas, F B; Smith, R; Wasserman, L H; Young, E F; Zacharias, M; Zacharias, N

    2013-01-01T23:59:59.000Z

    Combining stellar occultation observations probing Pluto's atmosphere from 1988 to 2013 and models of energy balance between Pluto's surface and atmosphere, we conclude that Pluto's atmosphere does not collapse at any point in its 248-year orbit. The occultation results show an increasing atmospheric pressure with time in the current epoch, a trend present only in models with a high thermal inertia and a permanent N2 ice cap at Pluto's north rotational pole.

  1. Observational Studies of Atmospheric Aerosols over Bozeman, Montana, Using a Two-Color Lidar, a Water Vapor DIAL, a Solar Radiometer,

    E-Print Network [OSTI]

    Shaw, Joseph A.

    Observational Studies of Atmospheric Aerosols over Bozeman, Montana, Using a Two-Color Lidar form 24 June 2010) ABSTRACT Coordinated observational data of atmospheric aerosols were collected over-based nephelometer. The optical properties and spatial distribution of the atmospheric aerosols were inferred from

  2. Synthesis and transport property of AgSbTe{sub 2} as a promising thermoelectric compound

    SciTech Connect (OSTI)

    Wang Heng; Li Jingfeng; Zou Minmin; Sui Tao [State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2008-11-17T23:59:59.000Z

    Polycrystalline AgSbTe{sub 2} ternary compound materials with high phase purity were fabricated using a combined process of mechanical alloying and spark plasma sintering. It was found that stoichiometric AgSbTe{sub 2} is a promising composition for low-and-mediate temperature applications, whose ZT reaches 1.59 at 673 K, benefiting from its extremely low thermal conductivity (0.30 W/mK) in addition to its low electrical resistivity (<1.1x10{sup -4} {omega} m) and large positive Seebeck coefficient (260 {mu}V/K). On the other hand, deviating from this formula would lead to unstable phase structures and higher thermal conductivity, which make the samples less attractive as thermoelectric materials or components of thermoelectric systems.

  3. Doping Effects on the Thermoelectric Properties of Cu3SbSe4

    SciTech Connect (OSTI)

    Skoug, Eric [Michigan State University, East Lansing; Cain, Jeffrey D. [Michigan State University, East Lansing; Morelli, Donald [Michigan State University, East Lansing; Majsztrik, Paul W [ORNL; Kirkham, Melanie J [ORNL; Lara-Curzio, Edgar [ORNL

    2011-01-01T23:59:59.000Z

    We present the first systematic doping study on the ternary semiconductor Cu3SbSe 4 . We have developed a novel synthesis procedure that produces high-quality polycrystalline samples with hole concentrations an order of magnitude lower than have been reported for the undoped compound. The hole concentration can be increased by adding small amounts of either Ge or Sn on the Sb site. The power factor increases with increasing doping, reaching a maximum value of 16 W/cmK^2 . The thermoelectric properties are optimized for the 2% Sn doped compound which has ZT=0.72 at 630K, rivaling that of state-of-the-art thermoelectric materials in this temperature range.

  4. Height stabilization of GaSb/GaAs quantum dots by Al-rich capping

    SciTech Connect (OSTI)

    Smakman, E. P., E-mail: e.p.smakman@tue.nl; Koenraad, P. M. [Department of Applied Physics, Eindhoven University of Technology, Den Dolech 2, 5612 AZ Eindhoven (Netherlands); DeJarld, M.; Martin, A. J.; Millunchick, J. [Department of Material Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Luengo-Kovac, M.; Sih, V. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-09-01T23:59:59.000Z

    GaSb quantum dots (QDs) in a GaAs matrix are investigated with cross-sectional scanning tunneling microscopy (X-STM) and photoluminescence (PL). We observe that Al-rich capping materials prevent destabilization of the nanostructures during the capping stage of the molecular beam epitaxy (MBE) growth process and thus preserves the QD height. However, the strain induced by the absence of destabilization causes many structural defects to appear around the preserved QDs. These defects originate from misfit dislocations near the GaSb/GaAs interface and extend into the capping layer as stacking faults. The lack of a red shift in the QD PL suggests that the preserved dots do not contribute to the emission spectra. We suggest that a better control over the emission wavelength and an increase of the PL intensity is attainable by growing smaller QDs with an Al-rich overgrowth.

  5. Photoemission study of the electronic structure and charge density waves of Na2Ti2Sb2O

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

    Tan, S. Y.; Jiang, J.; Ye, Z. R.; Niu, X. H.; Song, Y.; Zhang, C. L.; Dai, P. C.; Xie, B. P.; Lai, X. C.; Feng, D. L.

    2015-04-30T23:59:59.000Z

    The electronic structure of Na2Ti2Sb2O single crystal is studied by photon energy and polarization dependent angle-resolved photoemission spectroscopy (ARPES). The obtained band structure and Fermi surface agree well with the band structure calculation of Na2Ti2Sb2O in the non-magnetic state, which indicates that there is no magnetic order in Na2Ti2Sb2O and the electronic correlation is weak. Polarization dependent ARPES results suggest the multi-band and multi-orbital nature of Na2Ti2Sb2O. Photon energy dependent ARPES results suggest that the electronic structure of Na2Ti2Sb2O is rather two-dimensional. Moreover, we find a density wave energy gap forms below the transition temperature and reaches 65 meV at 7 K, indicating that Na2Ti2Sb2O is likely a weakly correlated CDW material in the strong electron-phonon interaction regime. (author)

  6. Differential atmospheric tritium sampler

    DOE Patents [OSTI]

    Griesbach, O.A.; Stencel, J.R.

    1987-10-02T23:59:59.000Z

    An atmospheric tritium sampler is provided which uses a carrier gas comprised of hydrogen gas and a diluting gas, mixed in a nonexplosive concentration. Sample air and carrier gas are drawn into and mixed in a manifold. A regulator meters the carrier gas flow to the manifold. The air sample/carrier gas mixture is pulled through a first moisture trap which adsorbs water from the air sample. The moisture then passes through a combustion chamber where hydrogen gas in the form of H/sub 2/ or HT is combusted into water. The manufactured water is transported by the air stream to a second moisture trap where it is adsorbed. The air is then discharged back into the atmosphere by means of a pump.

  7. Differential atmospheric tritium sampler

    DOE Patents [OSTI]

    Griesbach, Otto A. (Langhorne, PA); Stencel, Joseph R. (Skillman, NJ)

    1990-01-01T23:59:59.000Z

    An atmospheric tritium sampler is provided which uses a carrier gas comprised of hydrogen gas and a diluting gas, mixed in a nonexplosive concentration. Sample air and carrier gas are drawn into and mixed in a manifold. A regulator meters the carrier gas flow to the manifold. The air sample/carrier gas mixture is pulled through a first moisture trap which adsorbs water from the air sample. The mixture then passes through a combustion chamber where hydrogen gas in the form of H.sub.2 or HT is combusted into water. The manufactured water is transported by the air stream to a second moisture trap where it is adsorbed. The air is then discharged back into the atmosphere by means of a pump.

  8. Gain and tuning characteristics of mid-infrared InSb quantum dot diode lasers

    SciTech Connect (OSTI)

    Lu, Q.; Zhuang, Q.; Hayton, J.; Yin, M.; Krier, A. [Physics Department, Lancaster University, Lancaster LA1 4YB (United Kingdom)

    2014-07-21T23:59:59.000Z

    There have been relatively few reports of lasing from InSb quantum dots (QDs). In this work, type II InSb/InAs QD laser diodes emitting in the mid-infrared at 3.1??m have been demonstrated and characterized. The gain was determined to be 2.9?cm{sup ?1} per QD layer, and the waveguide loss was ?15?cm{sup ?1} at 4?K. Spontaneous emission measurements below threshold revealed a blue shift of the peak wavelength with increasing current, indicating filling of ground state heavy hole levels in the QDs. The characteristic temperature, T{sub 0}?=?101?K below 50?K, but decreased to 48?K at higher temperatures. The emission wavelength of these lasers showed first a blue shift followed by a red shift with increasing temperature. A hybrid structure was used to fabricate the laser by combining a liquid phase epitaxy grown p-InAs{sub 0.61}Sb{sub 0.13}P{sub 0.26} lower cladding layer and an upper n{sup +} InAs plasmon cladding layer which resulted in a maximum operating temperature (T{sub max}) of 120?K in pulsed mode, which is the highest reported to date.

  9. High-Temperature Order/Disorder Transition in the Thermoelectric Cu3SbSe3

    SciTech Connect (OSTI)

    Kirkham, Melanie J [ORNL; Majsztrik, Paul W [ORNL; Skoug, Eric [Michigan State University, East Lansing; Morelli, Donald [Michigan State University, East Lansing; Wang, Hsin [ORNL; Porter, Wallace D [ORNL; Payzant, E Andrew [ORNL; Lara-Curzio, Edgar [ORNL

    2011-01-01T23:59:59.000Z

    We report the results from an investigation into the structural evolution of a potential new thermoelectric material, Cu3SbSe3, as a function of temperature from 25 to 390 C. From high-temperature X-ray diffraction data, the refined lattice parameters were seen to change non-linearly, but continuously, with temperature, with an increased rate of thermal expansion in the a and b lattice parameters from around 125 C until around 175 C and negative thermal expansion in the c axis from around 100 C until around 175 C. Crystallographic charge flipping analysis indicated an increase in the disorder of the copper cations with temperature. This reversible order/disorder phase transition in Cu3SbSe3 affects the transport properties, as evidenced by thermal diffusivity measurements, which change from negative to positive slope at the transition temperature. This structural change in Cu3SbSe3 has implications for its potential use in thermoelectric generators.

  10. Optical Expanders with Applications in Optical Computing

    E-Print Network [OSTI]

    Reif, John H.

    Optical Expanders with Applications in Optical Computing John H. Reif Akitoshi Yoshida July 20, 1999 Abstract We describe and investigate an optical system which we call an optical expander. An optical expander elec- trooptically expands an optical boolean pattern encoded in d bits into an optical

  11. ARM - Atmospheric Heat Budget

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearchSOLICITATIONIMODI FICATION OFMaterialsAnnual Reports27,ListAtmospheric Heat

  12. ARM - Atmospheric Pressure

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearchSOLICITATIONIMODI FICATION OFMaterialsAnnual Reports27,ListAtmospheric

  13. Atmospheric PSF Interpolation

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem Not Found Item Not Found The itemAIR SEPARATION BYAbrasion andArticle)Atmospheric

  14. Fiber optic coupled optical sensor

    DOE Patents [OSTI]

    Fleming, Kevin J. (Albuquerque, NM)

    2001-01-01T23:59:59.000Z

    A displacement sensor includes a first optical fiber for radiating light to a target, and a second optical fiber for receiving light from the target. The end of the first fiber is adjacent and not axially aligned with the second fiber end. A lens focuses light from the first fiber onto the target and light from the target onto the second fiber.

  15. Spectrometer for Sky-Scanning Sun-Tracking Atmospheric Research (4STAR): Instrument Technology

    SciTech Connect (OSTI)

    Dunagan, Stephen; Johnson, Roy; Zavaleta, Jhony; Russell, P. B.; Schmid, Beat; Flynn, Connor J.; Redemann, Jens; Shinozuka, Yohei; Livingston, J.; Segal Rozenhaimer, Michal

    2013-08-06T23:59:59.000Z

    The Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) combines airborne sun tracking and sky scanning with diffraction spectroscopy, to improve knowledge of atmospheric constituents and their links to air-pollution/climate. Direct beam hyper-spectral measurement of optical depth improves retrievals of gas constituents and determination of aerosol properties. Sky scanning enhances retrievals of aerosol type and size distribution. 4STAR measurements will tighten the closure between satellite and ground-based measurements. 4STAR incorporates a modular sun-tracking/ sky-scanning optical head with fiber optic signal transmission to rack mounted spectrometers, permitting miniaturization of the external optical head, and future detector evolution. Technical challenges include compact optical collector design, radiometric dynamic range and stability, and broad spectral coverage. Test results establishing the performance of the instrument against the full range of operational requirements are presented, along with calibration, engineering flight test, and scientific field campaign data and results.

  16. Unusual magnetic hysteresis and the weakened transition behavior induced by Sn substitution in Mn{sub 3}SbN

    SciTech Connect (OSTI)

    Sun, Ying, E-mail: sunying@buaa.edu.cn [Center for Condensed Matter and Materials Physics, Department of Physics, Beihang University, Beijing 100191 (China); International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Guo, Yanfeng; Li, Jun; Wang, Xia [Superconducting Properties Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Tsujimoto, Yoshihiro [Materials Processing Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Wang, Cong [Center for Condensed Matter and Materials Physics, Department of Physics, Beihang University, Beijing 100191 (China); Feng, Hai L.; Sathish, Clastin I.; Yamaura, Kazunari, E-mail: yamaura.kazunari@nims.go.jp [Superconducting Properties Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Matsushita, Yoshitaka [Analysis Station, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan)

    2014-01-28T23:59:59.000Z

    Substitution of Sb with Sn was achieved in ferrimagnetic antiperovskite Mn{sub 3}SbN. The experimental results indicate that with an increase in Sn concentration, the magnetization continuously decreases and the crystal structure of Mn{sub 3}Sb{sub 1-x}Sn{sub x}N changes from tetragonal to cubic phase at around x of 0.8. In the doping series, step-like anomaly in the isothermal magnetization was found and this behavior was highlighted at x?=?0.4. The anomaly could be attributed to the magnetic frustration, resulting from competition between the multiple spin configurations in the antiperovskite lattice. Meantime, H{sub c} of 18 kOe was observed at x?=?0.3, which is probably the highest among those of manganese antiperovskite materials reported so far. With increasing Sn content, the abrupt change of resistivity and the sharp peak of heat capacity in Mn{sub 3}SbN were gradually weakened. The crystal structure refinements indicate the weakened change at the magnetic transition is close related to the change of c/a ratio variation from tetragonal to cubic with Sn content. The results derived from this study indicate that the behavior of Mn{sub 3}Sb{sub 1-x}Sn{sub x}N could potentially enhance its scientific and technical applications, such as spin torque transfer and hard magnets.

  17. Thermal conductivity of Zn{sub 4{minus}x}Cd{sub x}Sb{sub 3} solid solutions

    SciTech Connect (OSTI)

    Caillat, T.; Borshchevsky, A.; Fleurial, J.P.

    1997-07-01T23:59:59.000Z

    {beta}-Zn{sub 4}Sb{sub 3} was recently identified at the Jet Propulsion Laboratory as a new high performance p-type thermoelectric material with a maximum dimensionless thermoelectric figure of merit ZT of 1.4 at a temperature of 673K. A usual approach, used for many state-of-the-art thermoelectric materials, to further improve ZT values is to alloy {beta}-Zn{sub 4}Sb{sub 3} with isostructural compounds because of the expected decrease in lattice thermal conductivity. The authors have grown Zn{sub 4{minus}x}Cd{sub x}Sb{sub 3} crystals with 0.2 {le} x < 1.2 and measured their thermal conductivity from 10 to 500K. The thermal conductivity values of Zn{sub 4{minus}x}Cd{sub x}Sb{sub 3} alloys are significantly lower than those measured for {beta}-Zn{sub 4}Sb{sub 3} and are comparable to its calculated minimum thermal conductivity. A strong atomic disorder is believed to be primarily at the origin of the very low thermal conductivity of these materials which are also fairly good electrical conductors and are therefore excellent candidates for thermoelectric applications.

  18. NEGLECTED CLOUDS IN T AND Y DWARF ATMOSPHERES

    SciTech Connect (OSTI)

    Morley, Caroline V.; Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Marley, Mark S. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Visscher, Channon [Southwest Research Institute, Boulder, CO 80302 (United States); Saumon, Didier [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Leggett, S. K., E-mail: cmorley@ucolick.org [Gemini Observatory, Northern Operations Center, Hilo, HI 96720 (United States)

    2012-09-10T23:59:59.000Z

    As brown dwarfs cool, a variety of species condense in their atmospheres, forming clouds. Iron and silicate clouds shape the emergent spectra of L dwarfs, but these clouds dissipate at the L/T transition. A variety of other condensates are expected to form in cooler T dwarf atmospheres. These include Cr, MnS, Na{sub 2}S, ZnS, and KCl, but the opacity of these optically thinner clouds has not been included in previous atmosphere models. Here, we examine their effect on model T and Y dwarf atmospheres. The cloud structures and opacities are calculated using the Ackerman and Marley cloud model, which is coupled to an atmosphere model to produce atmospheric pressure-temperature profiles in radiative-convective equilibrium. We generate a suite of models between T{sub eff} = 400 and 1300 K, log g = 4.0 and 5.5, and condensate sedimentation efficiencies from f{sub sed} = 2 to 5. Model spectra are compared to two red T dwarfs, Ross 458C and UGPS 0722-05; models that include clouds are found to match observed spectra significantly better than cloudless models. The emergence of sulfide clouds in cool atmospheres, particularly Na{sub 2}S, may be a more natural explanation for the 'cloudy' spectra of these objects, rather than the reemergence of silicate clouds that wane at the L-to-T transition. We find that sulfide clouds provide a mechanism to match the near- and mid-infrared colors of observed T dwarfs. Our results indicate that including the opacity of condensates in T dwarf atmospheres is necessary to accurately determine the physical characteristics of many of the observed objects.

  19. Optical Expanders with Applications in Optical Computing

    E-Print Network [OSTI]

    Reif, John H.

    Optical Expanders with Applications in Optical Computing John H. Reif \\Lambda Akitoshi Yoshida \\Lambda July 20, 1999 Abstract We describe and investigate an optical system which we call an optical expander. An optical expander elec­ trooptically expands an optical boolean pattern encoded in d bits

  20. Sandia National Laboratories: atmospheric chemistry

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

    and atmospheric chemistry that is expected to benefit auto and engine manufacturers, oil and gas utilities, and other industries that employ combustion models. A paper...

  1. A MATHEMATICAL FRAMEWORK FOR THE LINEAR RECONSTRUCTOR PROBLEM IN ADAPTIVE OPTICS

    E-Print Network [OSTI]

    A MATHEMATICAL FRAMEWORK FOR THE LINEAR RECONSTRUCTOR PROBLEM IN ADAPTIVE OPTICS MOODY T. CHU aberrations induced by atmospheric turbulence can severely de­ grade the performance of an optical imaging system. Adaptive optics refers to the process of removing unwanted wave front distortions in real time, i

  2. A MATHEMATICAL FRAMEWORK FOR THE LINEAR RECONSTRUCTOR PROBLEM IN ADAPTIVE OPTICS

    E-Print Network [OSTI]

    A MATHEMATICAL FRAMEWORK FOR THE LINEAR RECONSTRUCTOR PROBLEM IN ADAPTIVE OPTICS MOODY T. CHU induced by atmospheric turbulence can severely de- grade the performance of an optical imaging system. Adaptive optics refers to the process of removing unwanted wave front distortions in real time, i

  3. Photocounting Array Receivers for Optical Communication Through the Lognormal Atmospheric

    E-Print Network [OSTI]

    Teich, Malvin C.

    to the background noise power density. The background noise takes into account various thermal radiation sources and their relative merits are presented positive gain (e.g., photomultipliers) the thermal noise introduced at each detector in the array.' These counts are Poisson distributed with constant mean, proportional

  4. Determining Nighttime Atmospheric Optical Depth Using Mars Exploration Rover Images 

    E-Print Network [OSTI]

    Bean, Keri Marie

    2013-07-22T23:59:59.000Z

    Martian clouds and dust play an important part of the radiative transfer and energy balance budget. To assist in fully understanding the impact of clouds and dust, the complete diurnal cycle needs to be characterized. One of the best methods...

  5. Hierardlicsl Diagnosis V. V. Zuev Institute of Atmospheric Optics

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cn SunnybankD.jpgHanfordDepartment ofHeatHenryDuncanC.-Y.J. Kao and

  6. ELSEVIER AtmosphericResearch 38 (1995) 207-235 ATMOSPHERIC

    E-Print Network [OSTI]

    Moelders, Nicole

    ELSEVIER AtmosphericResearch 38 (1995) 207-235 ATMOSPHERIC RESEARCH On the parameterization of ice and water substance mixing ratio fields were only strongly altered by turning off the ice phase of these schemes includes ice processes. But in mid- latitudes and also in tropics the ice phase is an important

  7. ATMOSPHERIC ELSEVIER AtmosphericResearch 44 (1997) 231-241

    E-Print Network [OSTI]

    Reading, University of

    ATMOSPHERIC RESEARCH ELSEVIER AtmosphericResearch 44 (1997) 231-241 Error analysis of backscatter;accepted 14 February 1997 Abstract Ice sphere backscatter has been calculated using both Mie theory as a reasonable approximation for rv 1997 Elsevier Science B.V. 1. Introduction Cirrus clouds play

  8. Optical Dielectric Functions of III-V Semiconductors in Wurtzite Phase

    E-Print Network [OSTI]

    Amrit De; Craig E. Pryor

    2010-11-13T23:59:59.000Z

    Optical properties of semiconductors can exhibit strong polarization dependence due to crystalline anisotropy. A number of recent experiments have shown that the photoluminescence intensity in free standing nanowires is polarization dependent. One contribution to this effect is the anisotropy of the dielectric function due to the fact that most nanowires crystalize in the wurtzite form. While little is known experimentally about the band structures wurtzite phase III-V semiconductors, we have previously predicted the bulk band structure of nine III-V semiconductors in wurtzite phase.Here, we predict the frequency dependent dielectric functions for nine non-Nitride wurtzite phase III-V semiconductors (AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs and InSb). Their complex dielectric functions are calculated in the dipole approximation by evaluating the momentum matrix elements on a dense grid of special k-points using empirical pseudopotential wave functions. Corrections to the momentum matrix elements accounting for the missing core states are made using a scaling factor which is determined by using the optical sum rules on the calculated dielectric functions for the zincblende polytypes. The dielectric function is calculated for polarizations perpendicular and parallel to the c-axis of the crystal.

  9. Reflected light from 3D exoplanetary atmospheres and simulation of HD 209458b

    E-Print Network [OSTI]

    Ben Hood; Kenneth Wood; Sara Seager; Andrew Collier Cameron

    2008-07-10T23:59:59.000Z

    We present radiation transfer models that demonstrate that reflected light levels from three dimensional (3D) exoplanetary atmospheres can be more than 50% lower than those predicted by models of homogeneous or smooth atmospheres. Compared to smooth models, 3D atmospheres enable starlight to penetrate to larger depths resulting in a decreased probability for the photons to scatter back out of the atmosphere before being absorbed. The increased depth of penetration of starlight in a 3D medium is a well known result from theoretical studies of molecular clouds and planetary atmospheres. For the first time we study the reflectivity of 3D atmospheres as a possible explanation for the apparent low geometric albedos inferred for extrasolar planetary atmospheres. Our models indicate that 3D atmospheric structure may be an important contributing factor to the non-detections of scattered light from exoplanetary atmospheres. We investigate the self-shadowing radiation transfer effects of patchy cloud cover in 3D scattered light simulations of the atmosphere of HD209458b. We find that, for a generic planet, geometric albedos can be as high as 0.45 in some limited situations, but that in general the geometric albedo is much lower. We conclude with some explanations on why extrasolar planets are likely dark at optical wavelengths.

  10. Long wavelength, high gain InAsSb strained-layer superlattice photoconductive detectors

    DOE Patents [OSTI]

    Biefeld, Robert M. (Albuquerque, NM); Dawson, L. Ralph (Albuquerque, NM); Fritz, Ian J. (Albuquerque, NM); Kurtz, Steven R. (Albuquerque, NM); Zipperian, Thomas E. (Albuquerque, NM)

    1991-01-01T23:59:59.000Z

    A high gain photoconductive device for 8 to 12 .mu.m wavelength radiation including an active semiconductor region extending from a substrate to an exposed face, the region comprising a strained-layer superlattice of alternating layers of two different InAs.sub.1-x Sb.sub.x compounds having x>0.75. A pair of spaced electrodes are provided on the exposed face, and changes in 8 to 12 .mu.m radiation on the exposed face cause a large photoconductive gain between the spaced electrodes.

  11. Doping and pressure study of U sub 3 Sb sub 4 Pt sub 3

    SciTech Connect (OSTI)

    Canfield, P.C.; Lacerda, A.; Thompson, J.D.; Sparn, G.; Beyermann, W.P.; Hundley, M.F.; Fisk, Z.

    1991-01-01T23:59:59.000Z

    The effects of doping and pressure on the U{sub 3}Sb{sub 4}Pt{sub 3} system have been studied. Substitution of either trivalent Y or Lu for U causes significant changes in temperature dependence of the electrical resistance and magnitude of the linear coefficient of the specific heat, {gamma}. However, doping with tetravalent Th causes little change in {gamma}, even though it affects the electrical resistance in a manner similar to that seen in the cases of Lu and Y. Finally, the application of hydrostatic pressures up to 16.5 kbar causes no significant change in the electrical resistance. 10 refs., 4 figs.

  12. Unique nanostructures and enhanced thermoelectric performance of melt-spun BiSbTe alloys

    SciTech Connect (OSTI)

    Xie Wenjie [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634-0978 (United States); Tang Xinfeng; Yan Yonggao; Zhang Qingjie [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Tritt, Terry M. [Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634-0978 (United States)

    2009-03-09T23:59:59.000Z

    We report a melt spinning technique followed by a quick spark plasma sintering procedure to fabricate high-performance p-type Bi{sub 0.52}Sb{sub 1.48}Te{sub 3} bulk material with unique microstructures. The microstructures consist of nanocrystalline domains embedded in amorphous matrix and 5-15 nm nanocrystals with coherent grain boundary. The significantly reduced thermal conductivity leads to a state-of-the-art dimensionless figure of merit ZT{approx}1.56 at 300 K, more than 50% improvement of that of the commercial Bi{sub 2}Te{sub 3} ingot materials.

  13. Angular dependence of metamagnetic transitions in DyAgSb2

    E-Print Network [OSTI]

    Myers, KD; Canfield, PC; Kalatsky, VA; Pokrovsky, Valery L.

    1999-01-01T23:59:59.000Z

    -dependent critical fields. Recent theoretical work2 has analyzed these data within the frame- PRB 590163-1829/99/59~2!/1121~8!/$15.00 c transitions in DyAgSb2 P. C. Canfield , Iowa State University, Ames, Iowa 50010 V. L. Pokrovsky , College Station, Texas...! are magnetic isotherm for the sample cooled to 2 K from 12 K in a 19.7 kOe field. Note: the plateau at 19.7 kOe is stabilized by field cool- PRB 59, AND POKROVSKY ing. Inset: M (T) in 19.7 kOe for increasing ~s! and decreasing temperature ~j!. O given...

  14. Growth of an {alpha}-Sn film on an InSb(111) A-(2x2) surface

    SciTech Connect (OSTI)

    Kondo, Daiyu; Sakamoto, Kazuyuki; Shima, Masahide; Takeyama, Wakaba [Department of Physics, Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan); Nakamura, Kenya; Ono, Kanta; Oshima, Masaharu [Department of Applied Chemistry, Graduate School of Engineering, University of Tokyo, Tokyo 113-0033 (Japan); Kasukabe, Yoshitaka [Department of Electronic Engineering/International Student Center, Tohoku University, Sendai 980-8578 (Japan)

    2004-12-15T23:59:59.000Z

    We have investigated the initial growth process of {alpha}-Sn films on the In-terminated InSb(111)A-(2x2) surface using low-energy electron diffraction (LEED) and high-resolution core-level photoelectron spectroscopy. Taking the LEED observation and the Sn coverage-dependent integrated intensities of the In 4d, Sb 4d, and Sn 4d core-level spectra into account, we conclude that the {alpha}-Sn film grows epitaxially by a bilayer mode and that there is no interdiffusion of the substrate atoms as suggested in the literature. Furthermore, the coverage-dependent In 4d and Sn 4d core levels indicate that the In vacancy site of InSb(111)A-(2x2) surface is not the preferable Sn absorption site.

  15. Electrical and microstructure analysis of nickel-based low-resistance ohmic contacts to n-GaSb

    SciTech Connect (OSTI)

    Rahimi, Nassim, E-mail: nrahimi@unm.edu; Aragon, Andrew A.; Romero, Orlando S.; Shima, Darryl M.; Rotter, Thomas J.; Mukherjee, Sayan D.; Balakrishnan, Ganesh [Center for High Technology Materials, University of New Mexico, Albuquerque, New Mexico 87106 (United States); Lester, Luke F. [Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, 302 Whittemore, Blacksburg, Virginia, 24061 (United States)

    2013-12-01T23:59:59.000Z

    Ultra low resistance ohmic contacts are fabricated on n-GaSb grown by molecular beam epitaxy. Different doping concentrations and n-GaSb thicknesses are studied to understand the tunneling transport mechanism between the metal contacts and the semiconductor. Different contact metallization and anneal process windows are investigated to achieve optimal penetration depth of Au in GaSb for low resistances. The fabrication, electrical characterization, and microstructure analysis of the metal-semiconductor interfaces created during ohmic contact formation are discussed. The characterization techniques include cross-sectional transmission electron microscopy and energy dispersive spectroscopy. Specific transfer resistances down to 0.1 ??mm and specific contact resistances of 1 × 10{sup ?6} ??cm{sup 2} are observed.

  16. Micro-Raman spectroscopy of mechanically exfoliated few-quintuple layers of Bi2Te3, Bi2Se3, and Sb2Te3 materials

    E-Print Network [OSTI]

    Micro-Raman spectroscopy of mechanically exfoliated few-quintuple layers of Bi2Te3, Bi2Se3, and Sb2-like" exfoliated few-quintuple layers of Bi2Te3, Bi2Se3, and Sb2Te3. It is found that crystal symmetry breaking

  17. Structural phase transitions on the nanoscale: The crucial pattern in the phase-change materials Ge2Sb2Te5 and GeTe

    E-Print Network [OSTI]

    Structural phase transitions on the nanoscale: The crucial pattern in the phase-change materials Ge2Sb2Te5 and GeTe J. Akola1,2 and R. O. Jones1 1Institut für Festkörperforschung, Forschungszentrum to characterize the amorphous structure of the prototype materials Ge2Sb2Te5 and GeTe. In both, there is long

  18. Synthesis and thermoelectric properties of Ce(Ru0.67Rh0.33)4Sb12. Geoff D. Staneff1

    E-Print Network [OSTI]

    Asimow, Paul D.

    Synthesis and thermoelectric properties of Ce(Ru0.67Rh0.33)4Sb12. Geoff D. Staneff1 , Paul D compositions show promise for thermoelectric applications. Current work was undertaken with a nominal composition of Ce(Ru0.67Rh0.33)4Sb12 to experimentally verify its potential as an n-type thermoelectric

  19. Space Science : Atmosphere Greenhouse Effect

    E-Print Network [OSTI]

    Johnson, Robert E.

    Space Science : Atmosphere Greenhouse Effect Part-5a Solar + Earth Spectrum IR Absorbers Grey Atmosphere Greenhouse Effect #12;Radiation: Solar and Earth Surface B"(T) Planck Ideal Emission Integrate at the carbon cycle #12;However, #12;Greenhouse Effect is Complex #12;PLANETARY ENERGY BALANCE G+W fig 3-5

  20. Ch4. Atmosphere and Surface Energy Balances

    E-Print Network [OSTI]

    Pan, Feifei

    ;Energy Pathways #12;Solar radiation transfer in the atmosphere Solar radiation Reflection Atmosphere or performing any work. #12;Solar radiation transfer in the atmosphere Solar radiation Reflection Transmission or water. #12;Solar radiation transfer in the atmosphere Solar radiation Reflection Transmission Atmosphere

  1. Design and fabrication of 6.1-.ANG. family semiconductor devices using semi-insulating A1Sb substrate

    DOE Patents [OSTI]

    Sherohman, John W. (Livermore, CA); Coombs, III, Arthur W. (Patterson, CA); Yee, Jick Hong (Livermore, CA); Wu, Kuang Jen J. (Cupertino, CA)

    2007-05-29T23:59:59.000Z

    For the first time, an aluminum antimonide (AlSb) single crystal substrate is utilized to lattice-match to overlying semiconductor layers. The AlSb substrate establishes a new design and fabrication approach to construct high-speed, low-power electronic devices while establishing inter-device isolation. Such lattice matching between the substrate and overlying semiconductor layers minimizes the formation of defects, such as threaded dislocations, which can decrease the production yield and operational life-time of 6.1-.ANG. family heterostructure devices.

  2. Characteristics of radio-frequency atmospheric pressure dielectric-barrier discharge with dielectric electrodes

    SciTech Connect (OSTI)

    Hussain, S., E-mail: shussain@uos.edu.pk, E-mail: shussainuos@yahoo.com; Qazi, H. I. A.; Badar, M. A. [Department of Physics, University of Sargodha, 40100 Sargodha (Pakistan)] [Department of Physics, University of Sargodha, 40100 Sargodha (Pakistan)

    2014-03-15T23:59:59.000Z

    An experimental investigation to characterize the properties and highlight the benefits of atmospheric pressure radio-frequency dielectric-barrier discharge (rf DBD) with dielectric electrodes fabricated by anodizing aluminium substrate is presented. The current-voltage characteristics and millisecond images are used to distinguish the ? and ? modes. This atmospheric rf DBD is observed to retain the discharge volume without constriction in ? mode. Optical emission spectroscopy demonstrates that the large discharge current leads to more abundant reactive species in this plasma source.

  3. Atomic layer deposition of Al{sub 2}O{sub 3} on GaSb using in situ hydrogen plasma exposure

    SciTech Connect (OSTI)

    Ruppalt, Laura B.; Cleveland, Erin R.; Champlain, James G.; Prokes, Sharka M.; Brad Boos, J.; Park, Doewon; Bennett, Brian R. [Electronics Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2012-12-03T23:59:59.000Z

    In this report, we study the effectiveness of hydrogen plasma surface treatments for improving the electrical properties of GaSb/Al{sub 2}O{sub 3} interfaces. Prior to atomic layer deposition of an Al{sub 2}O{sub 3} dielectric, p-GaSb surfaces were exposed to hydrogen plasmas in situ, with varying plasma powers, exposure times, and substrate temperatures. Good electrical interfaces, as indicated by capacitance-voltage measurements, were obtained using higher plasma powers, longer exposure times, and increasing substrate temperatures up to 250 Degree-Sign C. X-ray photoelectron spectroscopy reveals that the most effective treatments result in decreased SbO{sub x}, decreased Sb, and increased GaO{sub x} content at the interface. This in situ hydrogen plasma surface preparation improves the semiconductor/insulator electrical interface without the use of wet chemical pretreatments and is a promising approach for enhancing the performance of Sb-based devices.

  4. Structural, Electrical, and Optical Properties of SnO2:Sb Films Prepared on Flexible Substrate at Room Temperature

    E-Print Network [OSTI]

    Boo, Jin-Hyo

    , and solar cells.1­5) The increased utilization of many transparent electrodes has recently accelerated for application in various fields such as gas sensors, optoelec- tronic devices, flat panel displays, heat mirrors

  5. Room temperature performance of mid-wavelength infrared InAsSb nBn detectors

    SciTech Connect (OSTI)

    Soibel, Alexander; Hill, Cory J.; Keo, Sam A.; Hoglund, Linda; Rosenberg, Robert; Kowalczyk, Robert; Khoshakhlagh, Arezou; Fisher, Anita; Ting, David Z.-Y.; Gunapala, Sarath D. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, California 91030 (United States)

    2014-07-14T23:59:59.000Z

    In this work, we investigate the high temperature performance of mid-wavelength infrared InAsSb-AlAsSb nBn detectors with cut-off wavelengths near 4.5??m. The quantum efficiency of these devices is 35% without antireflection coatings and does not change with temperature in the 77–325?K temperature range, indicating potential for room temperature operation. The current generation of nBn detectors shows an increase of operational bias with temperature, which is attributed to a shift in the Fermi energy level in the absorber. Analysis of the device performance shows that operational bias and quantum efficiency of these detectors can be further improved. The device dark current stays diffusion limited in the 150?K–325?K temperature range and becomes dominated by generation-recombination processes at lower temperatures. Detector detectivities are D*(?)?=?1?×?10{sup 9} (cm Hz{sup 0.5}/W) at T?=?300?K and D*(?)?=?5?×?10{sup 9} (cm Hz{sup 0.5}/W) at T?=?250?K, which is easily achievable with a one stage TE cooler.

  6. Decay heat removal during SB LOCA with loss of all feedwater

    SciTech Connect (OSTI)

    Prosek, A.; Mavko, B.; Petelin, S. [Jozef Stefan Institute, Ljubljana (Slovenia). Reactor Engineering Division

    1994-12-31T23:59:59.000Z

    The aim of this research was to investigate decay heat removal during SB LOCA with simultaneous loss of all feedwater in a two loop PWR plant. Following a SB LOCA, the major concern is to keep the core covered assuring decay heat removal from the core thereby preventing cladding damage. Analysis was performed based on the data for Krsko NPP in Slovenia. The spectrum of break sizes in the cold leg was analyzed using the RELAP5/MOD2 code. The results indicate that when the break diameter is lower than 2.5 cm, the steam generators will dry out and the primary side bleed and feed procedure should be initiated. For break diameters between 2.5 cm to 5.1 cm the decay heat can be removed by the break flow and by relieving the steam through the steam generator relief valves. For break diameters greater than 5.1 cm the break flow is sufficient to remove all dissipated decay heat.

  7. Effect on Sb on the Properties of GaInP Top Cells: Preprint

    SciTech Connect (OSTI)

    Olson, J. M.; McMahon, W. E.; Kurtz, S.

    2006-05-01T23:59:59.000Z

    It is well known that the efficiency of GaInP/GaAs tandem solar cells is limited by the band gap of the GaInP top cell, which, in turn, is determined by the degree of compositional ordering in GaInP base layer. Attempts to raise the band gap by the addition of Al to the top cell have met with limited success due to the strong affinity between Al and oxygen. Here we investigate a different approach. It has been shown that the presence of antimony on the surface of GaInP during its growth suppresses the ordering process and increases the band gap. In this paper, we study the effects of Sb on the properties of GaInP top cells. We show that, in addition to raising the band gap of GaInP, it also increases the incorporation of Zn and changes the relative incorporation of Ga and In. These effects depend strongly on the substrate orientation, growth temperature and rate, and the Sb/P ratio in the gas phase. We show that the band gap of the GaInP top cell (and the Voc) can be increased without reducing the minority carrier collection efficiency. The implications of these results are presented and discussed.

  8. Electrodeposition of InSb branched nanowires: Controlled growth with structurally tailored properties

    SciTech Connect (OSTI)

    Das, Suprem R.; Mohammad, Asaduzzaman; Janes, David B., E-mail: janes@ecn.purdue.edu [School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Akatay, Cem [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Khan, Mohammad Ryyan; Alam, Muhammad A. [School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Maeda, Kosuke [Department of Materials Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta–cho, Midori-ku, Yokohama 226-8502 (Japan); Advanced Device Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Deacon, Russell S.; Ishibashi, Koji [Advanced Device Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Chen, Yong P. [School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907 (United States); Sands, Timothy D. [School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States)

    2014-08-28T23:59:59.000Z

    In this article, electrodeposition method is used to demonstrate growth of InSb nanowire (NW) arrays with hierarchical branched structures and complex morphology at room temperature using an all-solution, catalyst-free technique. A gold coated, porous anodic alumina membrane provided the template for the branched NWs. The NWs have a hierarchical branched structure, with three nominal regions: a “trunk” (average diameter of 150?nm), large branches (average diameter of 100?nm), and small branches (average diameter of sub-10?nm to sub-20?nm). The structural properties of the branched NWs were studied using scanning transmission electron microscopy, transmission electron microscopy, scanning electron microscopy, x-ray diffraction, energy dispersive x-ray spectroscopy, and Raman spectroscopy. In the as-grown state, the small branches of InSb NWs were crystalline, but the trunk regions were mostly nanocrystalline with an amorphous boundary. Post-annealing of NWs at 420?°C in argon produced single crystalline structures along ?311? directions for the branches and along ?111? for the trunks. Based on the high crystallinity and tailored structure in this branched NW array, the effective refractive index allows us to achieve excellent antireflection properties signifying its technological usefulness for photon management and energy harvesting.

  9. Optical coupler

    DOE Patents [OSTI]

    Majewski, Stanislaw; Weisenberger, Andrew G.

    2004-06-15T23:59:59.000Z

    In a camera or similar radiation sensitive device comprising a pixilated scintillation layer, a light guide and an array of position sensitive photomultiplier tubes, wherein there exists so-called dead space between adjacent photomultiplier tubes the improvement comprising a two part light guide comprising a first planar light spreading layer or portion having a first surface that addresses the scintillation layer and optically coupled thereto at a second surface that addresses the photomultiplier tubes, a second layer or portion comprising an array of trapezoidal light collectors defining gaps that span said dead space and are individually optically coupled to individual position sensitive photomultiplier tubes. According to a preferred embodiment, coupling of the trapezoidal light collectors to the position sensitive photomultiplier tubes is accomplished using an optical grease having about the same refractive index as the material of construction of the two part light guide.

  10. Optical memory

    DOE Patents [OSTI]

    Mao, Samuel S; Zhang, Yanfeng

    2013-07-02T23:59:59.000Z

    Optical memory comprising: a semiconductor wire, a first electrode, a second electrode, a light source, a means for producing a first voltage at the first electrode, a means for producing a second voltage at the second electrode, and a means for determining the presence of an electrical voltage across the first electrode and the second electrode exceeding a predefined voltage. The first voltage, preferably less than 0 volts, different from said second voltage. The semiconductor wire is optically transparent and has a bandgap less than the energy produced by the light source. The light source is optically connected to the semiconductor wire. The first electrode and the second electrode are electrically insulated from each other and said semiconductor wire.

  11. Experimental study on the emission spectra of microwave plasma at atmospheric pressure

    SciTech Connect (OSTI)

    Zhang, Boya; Wang, Qiang; Zhang, Guixin, E-mail: guixin@mail.tsinghua.edu.cn [Department of Electrical Engineering, Tsinghua University, Beijing 100084 (China); Liao, Shanshan [Department of Electrical Engineering, Tsinghua University, Beijing 100084 (China); Shenzhen Power Supply Co. Ltd., Shenzhen 518000, Guangdong (China)

    2014-01-28T23:59:59.000Z

    An experimental study on microwave plasma at atmospheric pressure was conducted by employing optical emission spectroscopy. Based on a microwave plasma generation device developed for nanoparticle synthesis, we studied the influence of input microwave power and gas flow rate on the optical emission behaviors and electron temperature of plasma using Ar, He, and N{sub 2} as working gas, respectively. The physics behind these behaviors was discussed. The results are useful in characterizing microwave plasma at atmospheric pressure and can be used for improving nanoparticle synthesis system for commercial use in the future.

  12. Optical switch

    DOE Patents [OSTI]

    Reedy, R.P.

    1987-11-10T23:59:59.000Z

    An optical switching device is provided whereby light from a first glass fiber or a second glass fiber may be selectively transmitted into a third glass fiber. Each glass fiber is provided with a focusing and collimating lens system. In one mode of operation, light from the first glass fiber is reflected by a planar mirror into the third glass fiber. In another mode of operation, light from the second glass fiber passes directly into the third glass fiber. The planar mirror is attached to a rotatable table which is rotated to provide the optical switching. 3 figs.

  13. Modeling Atmospheric Aerosols V. Rao Kotamarthi

    E-Print Network [OSTI]

    Modeling Atmospheric Aerosols V. Rao Kotamarthi and Yan Feng Climate Research Section Environmental Science Division Argonne National Laboratory #12;Outline Atmospheric Aerosols and gas phase heterogeneous reactions Regional Scales and Atmospheric Aerosols Regional Scale Aerosols: Ganges Valley Aerosol

  14. Fragmentation Energetics of Clusters Relevant to Atmospheric...

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

    of Clusters Relevant to Atmospheric New Particle Formation. Fragmentation Energetics of Clusters Relevant to Atmospheric New Particle Formation. Abstract: The exact mechanisms by...

  15. PHOTOCHEMISTRY IN TERRESTRIAL EXOPLANET ATMOSPHERES. II. H{sub 2}S AND SO{sub 2} PHOTOCHEMISTRY IN ANOXIC ATMOSPHERES

    SciTech Connect (OSTI)

    Hu Renyu; Seager, Sara; Bains, William, E-mail: hury@mit.edu [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2013-05-20T23:59:59.000Z

    Sulfur gases are common components in the volcanic and biological emission on Earth, and are expected to be important input gases for atmospheres on terrestrial exoplanets. We study the atmospheric composition and the spectra of terrestrial exoplanets with sulfur compounds (i.e., H{sub 2}S and SO{sub 2}) emitted from their surfaces. We use a comprehensive one-dimensional photochemistry model and radiative transfer model to investigate the sulfur chemistry in atmospheres ranging from reducing to oxidizing. The most important finding is that both H{sub 2}S and SO{sub 2} are chemically short-lived in virtually all types of atmospheres on terrestrial exoplanets, based on models of H{sub 2}, N{sub 2}, and CO{sub 2} atmospheres. This implies that direct detection of surface sulfur emission is unlikely, as their surface emission rates need to be extremely high (>1000 times Earth's volcanic sulfur emission) for these gases to build up to a detectable level. We also find that sulfur compounds emitted from the surface lead to photochemical formation of elemental sulfur and sulfuric acid in the atmosphere, which would condense to form aerosols if saturated. For terrestrial exoplanets in the habitable zone of Sun-like stars or M stars, Earth-like sulfur emission rates result in optically thick haze composed of elemental sulfur in reducing H{sub 2}-dominated atmospheres for a wide range of particle diameters (0.1-1 {mu}m), which is assumed as a free parameter in our simulations. In oxidized atmospheres composed of N{sub 2} and CO{sub 2}, optically thick haze, composed of elemental sulfur aerosols (S{sub 8}) or sulfuric acid aerosols (H{sub 2}SO{sub 4}), will form if the surface sulfur emission is two orders of magnitude more than the volcanic sulfur emission of Earth. Although direct detection of H{sub 2}S and SO{sub 2} by their spectral features is unlikely, their emission might be inferred by observing aerosol-related features in reflected light with future generation space telescopes.

  16. Nepheline Formation Study for Sludge Batch 4 (SB4): Phase 1 Experimental Results

    SciTech Connect (OSTI)

    Peeler, D. K.; Edwards, T. B.; Reamer, I.A.; Workman, R. J.

    2005-09-30T23:59:59.000Z

    Although it is well known that the addition of Al{sub 2}O{sub 3} to borosilicate glasses enhances the durability of the waste form (through creation of network-forming tetrahedral Na+-[AlO{sub 4/2}]{sup -} pairs), the combination of high Al{sub 2}O{sub 3} and Na{sub 2}O can lead to the formation of nepheline (NaAlSiO{sub 4})--which can negatively impact durability. Given the projected high concentration of Al{sub 2}O{sub 3} in SB4 (Lilliston 2005) and the potential use of a high Na{sub 2}O based frit to improve melt rate and a high Na{sub 2}O sludge due to settling problems, the potential formation of nepheline in various SB4 systems continues to be assessed. Twelve SB4-based glasses were fabricated and their durabilities (via the Product Consistency Test [PCT]) measured to assess the potential for nepheline formation and its potential negative impact on durability. In terms of ''acceptability'', the results indicate that all of the study glasses produced are acceptable with respect to durability as defined by the PCT (normalized boron release values for all nepheline (NEPH) glasses were much lower than that of the Environmental Assessment (EA) glass (16.695 g/L)). The most durable glass is NEPH-04 (quenched) with a normalized boron release (NL [B]) of 0.61 g/L, while the least durable glass is NEPH-01 centerline canister cooled (ccc) with an NL [B] of 2.47 g/L (based on the measured composition). In terms of predictability, most of the study glasses are predictable by the {Delta}G{sub p} model. Those that are not predictable (i.e., they fall outside of the prediction limits) actually fall below the prediction interval (i.e., they are over predicted by the model) suggesting the model is conservative. The Phase 1 PCT results suggest that for those glasses prone to nepheline formation (using the 0.62 value developed by Li et al. (2003) as a guide), a statistically significant difference in PCT response was observed for the two heat treatments but the impact on durability was of little or no practical concern. When one couples the PCT responses with the X-Ray Diffraction (XRD) results and/or visual observations, one could conclude that the formation of nepheline in these glasses does have a negative impact on durability. However, that impact may be of statistical significance, but the practical impact may not be sufficient to avoid a specific candidate frit for the SB4 glass system. The results of this study not only suggest that the 0.62 value appears to be a reasonable guide to monitor sludge--frit systems with respect to potential nepheline formation, but also that the impact of nepheline, although statistically significant, has little or no practical impact in the SB4 system to durability as measured by the PCT. This latter statement must be qualified to some extent given only two glasses were selected which were actually ''prone to nepheline formation'' based on this general guide and the relatively volume % of nepheline formed based on XRD results ({approx} 0.5 vol%). If the presence of nepheline has no appreciable, adverse impact on durability for the recently revised SB4 systems, then as decisions regarding the viability of the SB4 options and the down select of candidate frits are pursued, little weight will be given to minimizing the likelihood of nepheline and the decisions will be dominated by waste throughput criteria. That is, the frit selection process will not have to consider the impact of nepheline on the ultimate durability of the product and can focus on recommending a frit that when coupled with the sludge can be processed over a waste loading (WL) interval of interest to the Defense Waste Processing Facility (DWPF) with melt rates meeting production expectations.

  17. Solubility study of Yb in n-type skutterudites YbxCo4Sb12 and their enhanced thermoelectric properties

    E-Print Network [OSTI]

    Yang, J.

    The solubility of Yb in Yb[subscript x]Co[subscript 4]Sb[subscript 12 was reported to be 0.19 in bulk skutterudites made by melting and slow cooling method. Surprisingly we increased x close to 0.5 by a special sample ...

  18. Theoretical performance of very long wavelength InAs/InxGa1 xSb superlattice based infrared detectors

    E-Print Network [OSTI]

    Flatte, Michael E.

    , and satellite-based surveillance. Present day infrared detection technology based on bulk Hg1 xCdxTe MCT alloys is facing significant challenges in this spectral region due to i a sensitive dependence of the energy gap tunneling currents. An alter- native infrared system, based on InAs/InxGa1 xSb superlat- tices SLs , shows

  19. Crystallization of Ge2Sb2Te5 nanometric phase change material clusters made by gas-phase condensation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Crystallization of Ge2Sb2Te5 nanometric phase change material clusters made by gas- phase=pdfcov Published by the AIP Publishing Articles you may be interested in Nanoscale nuclei in phase change materials phase change material clusters made by gas-phase condensation G. E. Ghezzi,1,2 R. Morel,3 A. Brenac,3 N

  20. Mapping two-way grids onto free-form surfaces P. Winslow S. Pellegrino S.B. Sharma

    E-Print Network [OSTI]

    Pellegrino, Sergio

    Mapping two-way grids onto free-form surfaces P. Winslow S. Pellegrino S.B. Sharma Department, however existing techniques focus on relatively simple geometrical rules and algorithms to map a grid onto in the Millennium Dome, London . Use of a grid structure, consisting of a lattice of rods (see Figure 1) may be more

  1. Environmental Chemistry II (Atmospheric Chemistry)

    E-Print Network [OSTI]

    Dibble, Theodore

    SYLLABUS FOR Environmental Chemistry II (Atmospheric Chemistry) FCH 511 Fall 2013 Theodore S/explaining the trends in J as a function of altitude and solar zenith angle. The second involves analyzing real

  2. THE MARTIAN ATMOSPHERIC BOUNDARY LAYER

    E-Print Network [OSTI]

    Spiga, Aymeric

    THE MARTIAN ATMOSPHERIC BOUNDARY LAYER A. Petrosyan,1 B. Galperin,2 S. E. Larsen,3 S. R. Lewis,4 A [Haberle et al., 1993a; Larsen et al., 2002; Hinson et al., 2008]. At night, convection is inhibited

  3. Sandia Energy - Quantum Optics

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

    Quantum Optics Home Energy Research EFRCs Solid-State Lighting Science EFRC Quantum Optics Quantum OpticsTara Camacho-Lopez2015-03-30T16:37:03+00:00 Quantum Optics with a Single...

  4. Atmospheric science and power production

    SciTech Connect (OSTI)

    Randerson, D. (ed.)

    1984-07-01T23:59:59.000Z

    This is the third in a series of scientific publications sponsored by the US Atomic Energy Commission and the two later organizations, the US Energy Research and Development Adminstration, and the US Department of Energy. The first book, Meteorology and Atomic Energy, was published in 1955; the second, in 1968. The present volume is designed to update and to expand upon many of the important concepts presented previously. However, the present edition draws heavily on recent contributions made by atmospheric science to the analysis of air quality and on results originating from research conducted and completed in the 1970s. Special emphasis is placed on how atmospheric science can contribute to solving problems relating to the fate of combustion products released into the atmosphere. The framework of this book is built around the concept of air-quality modeling. Fundamentals are addressed first to equip the reader with basic background information and to focus on available meteorological instrumentation and to emphasize the importance of data management procedures. Atmospheric physics and field experiments are described in detail to provide an overview of atmospheric boundary layer processes, of how air flows around obstacles, and of the mechanism of plume rise. Atmospheric chemistry and removal processes are also detailed to provide fundamental knowledge on how gases and particulate matter can be transformed while in the atmosphere and how they can be removed from the atmosphere. The book closes with a review of how air-quality models are being applied to solve a wide variety of problems. Separate analytics have been prepared for each chapter.

  5. Laser Atmospheric Studies with VERITAS

    E-Print Network [OSTI]

    C. M. Hui; for the VERITAS collaboration

    2007-09-25T23:59:59.000Z

    As a calibrated laser pulse propagates through the atmosphere, the amount of Rayleigh-scattered light arriving at the VERITAS telescopes can be calculated precisely. This technique was originally developed for the absolute calibration of ultra-high-energy cosmic-ray fluorescence telescopes but is also applicable to imaging atmospheric Cherenkov telescopes (IACTs). In this paper, we present two nights of laser data taken with the laser at various distances away from the VERITAS telescopes and compare it to Rayleigh scattering simulations.

  6. Optical aperture synthesis with electronically connected telescopes

    E-Print Network [OSTI]

    Dravins, Dainis; Nuñez, Paul D

    2015-01-01T23:59:59.000Z

    Highest resolution imaging in astronomy is achieved by interferometry, connecting telescopes over increasingly longer distances, and at successively shorter wavelengths. Here, we present the first diffraction-limited images in visual light, produced by an array of independent optical telescopes, connected electronically only, with no optical links between them. With an array of small telescopes, second-order optical coherence of the sources is measured through intensity interferometry over 180 baselines between pairs of telescopes, and two-dimensional images reconstructed. The technique aims at diffraction-limited optical aperture synthesis over kilometre-long baselines to reach resolutions showing details on stellar surfaces and perhaps even the silhouettes of transiting exoplanets. Intensity interferometry circumvents problems of atmospheric turbulence that constrain ordinary interferometry. Since the electronic signal can be copied, many baselines can be built up between dispersed telescopes, and over long...

  7. Thermoelectric properties of p-type (Bi{sub 1{minus}x}Sb{sub x}){sub 2}Te{sub 3} fabricated by mechanical alloying process

    SciTech Connect (OSTI)

    Jung, B.Y.; Choi, J.S.; Oh, T.S.; Hyun, D.B.

    1997-07-01T23:59:59.000Z

    Thermoelectric properties of polycrystalline (Bi{sub 1{minus}x}Sb{sub x}){sub 2}Te{sub 3} (0.75 {le} x {le} 0.85), fabricated by mechanical alloying and hot pressing methods, have been investigated. Formation of (Bi{sub 0.25}Sb{sub 0.75}){sub 2}Te{sub 3} alloy powder was completed by mechanical alloying for 5 hours at ball-to-material ratio of 5:1, and processing time for (Bi{sub 1{minus}sub x}Sb{sub x}){sub 2}Te{sub 3} formation increased with Sb{sub 2}Te{sub 3} content x. When (Bi{sub 0.25}Sb{sub 0.75}){sub 2}Te{sub 3} was hot pressed at temperatures ranging from 300 C to 550 C for 30 minutes, figure-of-merit increased with hot pressing temperature and maximum value of 2.8 x 10{sup {minus}3}/K could be obtained by hot pressing at 550 C. When hot pressed at 550 C, (Bi{sub 0.2}Sb{sub 0.8}){sub 2}Te{sub 3} exhibited figure-of-merit of 2.92 x 10{sup {minus}3}/K, which could be improved to 2.97 x 10{sup {minus}3}/K with addition of 1 wt% Sb as acceptor dopant.

  8. RELAP5 simulation of SB LOCA in a VVER 440 model

    SciTech Connect (OSTI)

    Parzer, I.; Mavko, B.; Petelin, S.

    1992-01-01T23:59:59.000Z

    The VVER-440-type plants differ considerably from western-type pressurized water reactors (PWR). The two main distinguishing characteristics are horizontal steam generators and loop seals in both hot and cold legs, which are lately a great safety concern worldwide. In 1987, the International Atomic Energy Agency (IAEA) organized and sponsored one of the tests performed on the Hungarian PMK-NVH test facility and called it IAEA-SPE-2. The test was chosen from a wider test matrix performed to investigate emergency core cooling system capability in VVER-440 plants for a small-break loss-of-coolant accident (SB LOCA). PMK-NVA is a one-loop, full-height, full-pressure model of the Hungarian Paks nuclear power plant, type VVER-440, Soviet production. The facility power level is 100%, according to the 1:2070 scaling factor.

  9. Properties of CoSb{sub 3} films grown by pulsed laser deposition

    SciTech Connect (OSTI)

    Christen, H.M.; Mandrus, D.G.; Norton, D.P.; Boatner, L.A.; Sales, B.C.

    1997-07-01T23:59:59.000Z

    Polycrystalline CoSb{sub 3} films were grown on a variety of electrically insulating substrates by pulsed laser ablation from a stoichiometric hot-pressed target. These films are fully crystallized in the skutterudite structure, and the grains exhibit a strongly preferred alignment of the cubic [310]-axis perpendicular to the substrate surface. The film quality is studied for different single-crystal substrates and as a function of growth temperature and background gas. Hall measurements show that the films are p-type semiconducting with a room-temperature carrier density of 3 x 10{sup 20} holes/cm{sup 3}. The Hall mobility is found to be 50 to 60 cm{sup 2}/Vs, which is high for such a heavily-doped material. The Seebeck coefficient and the resistivity are measured as a function of temperature and are compared to bulk measurements.

  10. NGC 1266: Characterization of the Nuclear Molecular Gas in an Unusual SB0 Galaxy

    E-Print Network [OSTI]

    Glenn, Jason; Maloney, Philip R; Kamenetzky, Julia R

    2015-01-01T23:59:59.000Z

    With a substantial nuclear molecular gas reservoir and broad, high-velocity CO molecular line wings previously interpreted as an outflow, NGC 1266 is a rare SB$0$ galaxy. Previous analyses of interferometry, spectrally resolved low-$J$ CO emission lines, and unresolved high-$J$ emission lines have established basic properties of the molecular gas and the likely presence of an AGN. Here, new spectrally resolved CO $J = 5 - 4$ to $J = 8 - 7$ lines from {\\it Herschel Space Observatory} HIFI observations are combined with ground-based observations and high-$J$ {\\it Herschel} SPIRE observations to decompose the nuclear and putative outflow velocity components and to model the molecular gas to quantify its properties. Details of the modeling and results are described, with comparisons to previous results and exploration of the implications for the gas excitation mechanisms. Among the findings, like for other galaxies, the nuclear and putative outflow molecular gas are well represented by components that are cool ($...

  11. Evaluation of electron mobility in InSb quantum wells by means of percentage-impact

    SciTech Connect (OSTI)

    Mishima, T. D.; Edirisooriya, M.; Santos, M. B. [Homer L. Dodge Department of Physics and Astronomy, and Center for Semiconductor Physics in Nanostructure, University of Oklahoma, 440 W. Brooks St., Norman, OK 73019 (United States)

    2014-05-15T23:59:59.000Z

    In order to quantitatively analyze the contribution of each scattering factor toward the total carrier mobility, we use a new convenient figure-of-merit, named a percentage impact. The mobility limit due to a scattering factor, which is widely used to summarize a scattering analysis, has its own advantage. However, a mobility limit is not quite appropriate for the above purpose. A comprehensive understanding of the difference in contribution among many scattering factors toward the total carrier mobility can be obtained by evaluating percentage impacts of scattering factors, which can be straightforwardly calculated from their mobility limits and the total mobility. Our percentage impact analysis shows that threading dislocation is one of the dominant scattering factors for the electron transport in InSb quantum wells at room temperature.

  12. Radiometric Correctionradiometric correction Radiometric correction is important to ensure that terrestrial variables retrieved from optical satellite sensor

    E-Print Network [OSTI]

    Coburn, Craig

    that terrestrial variables retrieved from optical satellite sensor systems are calibrated to a common physical interactions. Radiometric corrections of optical sensor data consider sensor radiometric calibration, surface reflectance propagated through the atmosphere to the satellite sensor. Given that the optical properties

  13. Parallel optical sampler

    DOE Patents [OSTI]

    Tauke-Pedretti, Anna; Skogen, Erik J; Vawter, Gregory A

    2014-05-20T23:59:59.000Z

    An optical sampler includes a first and second 1.times.n optical beam splitters splitting an input optical sampling signal and an optical analog input signal into n parallel channels, respectively, a plurality of optical delay elements providing n parallel delayed input optical sampling signals, n photodiodes converting the n parallel optical analog input signals into n respective electrical output signals, and n optical modulators modulating the input optical sampling signal or the optical analog input signal by the respective electrical output signals, and providing n successive optical samples of the optical analog input signal. A plurality of output photodiodes and eADCs convert the n successive optical samples to n successive digital samples. The optical modulator may be a photodiode interconnected Mach-Zehnder Modulator. A method of sampling the optical analog input signal is disclosed.

  14. High thermoelectric performance BiSbTe alloy with unique low-dimensional structure

    SciTech Connect (OSTI)

    Xie Wenjie [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634-0978 (United States); Tang Xinfeng; Yan Yonggao; Zhang Qingjie [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Tritt, Terry M. [Department of Physics and Astronomy, Clemson University, Clemson, South Carolina 29634-0978 (United States)

    2009-06-01T23:59:59.000Z

    We report a detailed description of an innovative route of a melt spinning (MS) technique combined with a subsequent spark plasma sintering process in order to obtain high performance p-type Bi{sub 0.52}Sb{sub 1.48}Te{sub 3} bulk material, which possesses a unique low-dimensional structure. The unique structure consists of an amorphous structure, 5-15 nm fine nanocrystalline regions, and coherent interfaces between the resulting nanocrystalline regions. Measurements of the thermopower, electrical conductivity, and thermal conductivity have been performed over a range of temperature of 300-400 K. We found that MS technique can give us considerable control over the resulting nanostructure with good thermal stability during the temperature range of 300-400 K and this unique structure can effectively adjust the transport of phonons and electrons, in a manner such that it is beneficial to the overall thermoelectric performance of the material, primarily a reduction in the lattice thermal conductivity. Subsequently, this results in a maximum figure of merit ZT value of 1.56 at 300 K for p-type Bi{sub 0.52}Sb{sub 1.48}Te{sub 3} bulk material. This ZT value is over a 50% improvement of that of the state of the art commercial Bi{sub 2}Te{sub 3} materials. We also report results of thermal cycling of this material for over one hundred cycles between 300-400 K. Our work offers an innovative route for developing high performance bismuth telluride based alloys and devices, which have even broader prospects for commercial applications. This technique may also be applicable to other thermoelectric materials.

  15. Ultrafast optics For optics and photonics course,

    E-Print Network [OSTI]

    Palffy-Muhoray, Peter

    ultrafast and ultrashort generally describe pulses of widths in the nanosecond to femtosecond, or shorterUltrafast optics For optics and photonics course, Spring 2012 By :Alireza Moheghi Ultrafast optics, regimes. · Interest in ultrashort optical pulses began with the invention of the laser, · Ultrashort

  16. Electro-optical SLS devices for operating at new wavelength ranges

    DOE Patents [OSTI]

    Osbourn, Gordon C. (Albuquerque, NM)

    1986-01-01T23:59:59.000Z

    An intrinsic semiconductor electro-optical device includes a p-n junction intrinsically responsive, when cooled, to electromagnetic radiation in the wavelength range of 8-12 um. The junction consists of a strained-layer superlattice of alternating layers of two different III-V semiconductors having mismatched lattice constants when in bulk form. A first set of layers is either InAs.sub.1-x Sb.sub.x (where x is aobut 0.5 to 0.7) or In.sub.1-x Ga.sub.x As.sub.1-y Sb.sub.y (where x and y are chosen such that the bulk bandgap of the resulting layer is about the same as the minimum bandgap in the In.sub.1-x Ga.sub.x As.sub.1-y Sb.sub.y family). The second set of layers has a lattice constant larger than the lattice constant of the layers in the first set.

  17. Using observations of deep convective systems to constrain atmospheric column absorption of solar radiation in the

    E-Print Network [OSTI]

    Dong, Xiquan

    column absorption of solar radiation (Acol) is a fundamental part of the Earth's energy cycle.e., the Acol values at both regions converge to the same value ($0.27 of the total incoming solar radiation to constrain atmospheric column absorption of solar radiation in the optically thick limit, J. Geophys. Res

  18. Optics and Optical Engineering Program Assessment Plan Program Learning Objectives

    E-Print Network [OSTI]

    Cantlon, Jessica F.

    Optics and Optical Engineering Program Assessment Plan Program Learning, and processes that underlie optics and optical engineering. 2. Strong understanding of the fundamental science, mathematics, and processes that underlie optics and optical

  19. OUMBE, Armel, WALD, Lucien, BLANC, Philippe, and SCHROEDTER-HOMSCHEIDT, Marion. Exploitation of radiative transfer model for assessing solar radiation: the relative importance of atmospheric

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of radiative transfer model for assessing solar radiation: the relative importance of atmospheric constituents, Germany * Corresponding Author, armel.oumbe@ensmp.fr Abstract Solar radiation is modified in its way: solar radiation, atmospheric optics, satellite images, Heliosat method 1. Introduction A wealth

  20. Oscillations of solar atmosphere neutrinos

    E-Print Network [OSTI]

    G. L. Fogli; E. Lisi; A. Mirizzi; D. Montanino; P. D. Serpico

    2006-11-10T23:59:59.000Z

    The Sun is a source of high energy neutrinos (E > 10 GeV) produced by cosmic ray interactions in the solar atmosphere. We study the impact of three-flavor oscillations (in vacuum and in matter) on solar atmosphere neutrinos, and calculate their observable fluxes at Earth, as well as their event rates in a kilometer-scale detector in water or ice. We find that peculiar three-flavor oscillation effects in matter, which can occur in the energy range probed by solar atmosphere neutrinos, are significantly suppressed by averaging over the production region and over the neutrino and antineutrino components. In particular, we find that the relation between the neutrino fluxes at the Sun and at the Earth can be approximately expressed in terms of phase-averaged ``vacuum'' oscillations, dominated by a single mixing parameter (the angle theta_23).

  1. Cumulant expansions for atmospheric flows

    E-Print Network [OSTI]

    Ait-Chaalal, Farid; Meyer, Bettina; Marston, J B

    2015-01-01T23:59:59.000Z

    The equations governing atmospheric flows are nonlinear, and consequently the hierarchy of cumulant equations is not closed. But because atmospheric flows are inhomogeneous and anisotropic, the nonlinearity may manifests itself only weakly through interactions of mean fields with disturbances such as thermals or eddies. In such situations, truncations of the hierarchy of cumulant equations hold promise as a closure strategy. We review how truncations at second order can be used to model and elucidate the dynamics of turbulent atmospheric flows. Two examples are considered. First, we study the growth of a dry convective boundary layer, which is heated from below, leading to turbulent upward energy transport and growth of the boundary layer. We demonstrate that a quasilinear truncation of the equations of motion, in which interactions of disturbances among each other are neglected but interactions with mean fields are taken into account, can successfully capture the growth of the convective boundary layer. Seco...

  2. Optical microphone

    DOE Patents [OSTI]

    Veligdan, James T. (Manorville, NY)

    2000-01-11T23:59:59.000Z

    An optical microphone includes a laser and beam splitter cooperating therewith for splitting a laser beam into a reference beam and a signal beam. A reflecting sensor receives the signal beam and reflects it in a plurality of reflections through sound pressure waves. A photodetector receives both the reference beam and reflected signal beam for heterodyning thereof to produce an acoustic signal for the sound waves. The sound waves vary the local refractive index in the path of the signal beam which experiences a Doppler frequency shift directly analogous with the sound waves.

  3. Optical devices

    DOE Patents [OSTI]

    Chaves, Julio C.; Falicoff, Waqidi; Minano, Juan C.; Benitez, Pablo; Dross, Oliver; Parkyn Jr., William A.

    2010-07-13T23:59:59.000Z

    An optical manifold for efficiently combining a plurality of blue LED outputs to illuminate a phosphor for a single, substantially homogeneous output, in a small, cost-effective package. Embodiments are disclosed that use a single or multiple LEDs and a remote phosphor, and an intermediate wavelength-selective filter arranged so that backscattered photoluminescence is recycled to boost the luminance and flux of the output aperture. A further aperture mask is used to boost phosphor luminance with only modest loss of luminosity. Alternative non-recycling embodiments provide blue and yellow light in collimated beams, either separately or combined into white.

  4. Optical microfluidics

    SciTech Connect (OSTI)

    Kotz, K.T.; Noble, K.A.; Faris, G.W. [Molecular Physics Laboratory, SRI International, 333 Ravenswood Avenue, Menlo Park, California 94025 (United States)

    2004-09-27T23:59:59.000Z

    We present a method for the control of small droplets based on the thermal Marangoni effect using laser heating. With this approach, droplets covering five orders of magnitude in volume ({approx}1.7 {mu}L to 14 pL), immersed in decanol, were moved on an unmodified polystyrene surface, with speeds of up to 3 mm/s. When two droplets were brought into contact, they spontaneously fused and rapidly mixed in less than 33 ms. This optically addressed microfluidic approach has many advantages for microfluidic transport, including exceptional reconfigurability, low intersample contamination, large volume range, extremely simple substrates, no electrical connections, and ready scaling to large arrays.

  5. Dramatic thermal conductivity reduction by nanostructures for large increase in thermoelectric figure-of-merit of FeSb[subscript 2

    E-Print Network [OSTI]

    Chen, Gang

    In this report, thermal conductivity reduction by more than three orders of magnitude over its single crystal counterpart for the strongly correlated system FeSb[subscript 2] through a nanostructure approach was presented, ...

  6. Enhanced photoelectrochemical performance of rutile TiO{sub 2} by Sb-N donor-acceptor coincorporation from first principles calculations

    SciTech Connect (OSTI)

    Niu Mang; Xu Wenjie; Shao Xiaohong [College of Science, Beijing University of Chemical Technology, Beijing 100029 (China); Cheng Daojian [Division of Molecular and Materials Simulation, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China)

    2011-11-14T23:59:59.000Z

    An effective non-metal (N) and non-transition metal (Sb) passivated co-doping approach is proposed to improve the photoelectochemical performance of rutile TiO{sub 2} for water-splitting by using first-principles calculations. It is found that the band edges of N + Sb co-doped TiO{sub 2} match with the redox potentials of water, and a narrow band gap (2.0 eV) is achieved for enhanced visible light absorption. The compensated donor (Sb) and acceptor (N) pairs could prevent the recombination of photo-generated electron-hole pairs. In addition, the N + Sb defect pairs tend to bind with each other, which could enhance the stability and N concentration of the system.

  7. Simulation of Crystallization in Ge[subscript 2]Sb[subscript 2]Te[subscript 2]: A Memory Effect in the Canonical Phase-Change Material

    E-Print Network [OSTI]

    Akola, J.

    Crystallization of amorphous Ge[subscript 2]Sb[subscript 2]Te[subscript 5] (GST) has been studied using four extensive (460 atoms, up to 4 ns) density functional/molecular dynamics simulations at 600 K. This phase change ...

  8. 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., E-mail: canli1983@gmail.com; Zhao, Y. F.; Fu, C. X.; Gong, Y. Y. [Center for Coordination Bond Engineering, School of Materials Science and Engineering, China Jiliang University (China); Chi, B. Q. [College of Modem Science and Technology, Jiliang University, Hangzhou, 310018 (China); Sun, C. Q. [Center for Coordination Bond Engineering, School of Materials Science and Engineering, China Jiliang University (China); School of Electrical and Electronic Engineering, Nanyang Technological University, 639798 (Singapore)

    2014-10-15T23:59:59.000Z

    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.

  9. Visible-light absorption and large band-gap bowing of GaN1-xSbx from first principles

    SciTech Connect (OSTI)

    Sheetz, R. Michael; Richter, Ernst; Andriotis, Antonis N.; Lisenkov, Sergey; Pendyala, Chandrashekhar; Sunkara, Mahendra K.; Menon, Madhu

    2011-08-01T23:59:59.000Z

    Applicability of the Ga(Sbx)N1-x alloys for practical realization of photoelectrochemical water splitting is investigated using first-principles density functional theory incorporating the local density approximation and generalized gradient approximation plus the Hubbard U parameter formalism. Our calculations reveal that a relatively small concentration of Sb impurities is sufficient to achieve a significant narrowing of the band gap, enabling absorption of visible light. Theoretical results predict that Ga(Sbx)N1-x alloys with 2-eV band gaps straddle the potential window at moderate to low pH values, thus indicating that dilute Ga(Sbx)N1-x alloys could be potential candidates for splitting water under visible light irradiation.

  10. Active galactic nuclei synapses: X-ray versus optical classifications using artificial neural networks

    E-Print Network [OSTI]

    Gonzalez-Martin, O; Acosta-Pulido, J A; Masegosa, J; Papadakis, I E; Rodriguez-Espinosa, J M; Marquez, I; Hernandez-Garcia, L

    2014-01-01T23:59:59.000Z

    (Abridged) Many classes of active galactic nuclei (AGN) have been defined entirely throughout optical wavelengths while the X-ray spectra have been very useful to investigate their inner regions. However, optical and X-ray results show many discrepancies that have not been fully understood yet. The aim of this paper is to study the "synapses" between the X-ray and optical classifications. For the first time, the new EFLUXER task allowed us to analyse broad band X-ray spectra of emission line nuclei (ELN) without any prior spectral fitting using artificial neural networks (ANNs). Our sample comprises 162 XMM-Newton/pn spectra of 90 local ELN in the Palomar sample. It includes starbursts (SB), transition objects (T2), LINERs (L1.8 and L2), and Seyferts (S1, S1.8, and S2). The ANNs are 90% efficient at classifying the trained classes S1, S1.8, and SB. The S1 and S1.8 classes show a wide range of S1- and S1.8-like components. We suggest that this is related to a large degree of obscuration at X-rays. The S1, S1.8...

  11. Atomistic modeling and HAADF investigations of misfit and threading dislocations in GaSb/GaAs hetero-structures for applications in high electron mobility transistors

    SciTech Connect (OSTI)

    Ruterana, Pierre, E-mail: pierre.ruterana@ensicaen.fr; Wang, Yi, E-mail: pierre.ruterana@ensicaen.fr; Chen, Jun, E-mail: pierre.ruterana@ensicaen.fr; Chauvat, Marie-Pierre, E-mail: pierre.ruterana@ensicaen.fr [CIMAP, UMR 6252 CNRS, 6 Boulevard du Maréchal Juin, 14050 Caen Cedex (France); El Kazzi, S.; Deplanque, L.; Wallart, X. [IEMN, UMR-CNRS 8520, CS 60069, 59652 Villeneuve d'Ascq Cedex (France)

    2014-10-06T23:59:59.000Z

    A detailed investigation on the misfit and threading dislocations at GaSb/GaAs interface has been carried out using molecular dynamics simulation and quantitative electron microscopy techniques. The sources and propagation of misfit dislocations have been elucidated. The nature and formation mechanisms of the misfit dislocations as well as the role of Sb on the stability of the Lomer configuration have been explained.

  12. New method for atmospheric calibration at the Pierre Auger Observatory using FRAM, a robotic astronomical telescope

    E-Print Network [OSTI]

    Segev BenZvi; Martina Bohacova; Brian Connolly; Jiri Grygar; Miroslav Hrabovsky; Tatiana Karova; Dusan Mandat; Petr Necesal; Dalibor Nosek; Libor Nozka; Miroslav Palatka; Miroslav Pech; Michael Prouza; Jan Ridky; Petr Schovanek; Radomir Smida; Petr Travnicek; Primo Vitale; Stefan Westerhoff; for the Pierre Auger Collaboration

    2007-06-12T23:59:59.000Z

    FRAM - F/(Ph)otometric Robotic Atmospheric Monitor is the latest addition to the atmospheric monitoring instruments of the Pierre Auger Observatory. An optical telescope equipped with CCD camera and photometer, it automatically observes a set of selected standard stars and a calibrated terrestrial source. Primarily, the wavelength dependence of the attenuation is derived and the comparison between its vertical values (for stars) and horizontal values (for the terrestrial source) is made. Further, the integral vertical aerosol optical depth can be obtained. A secondary program of the instrument, the detection of optical counterparts of gamma-ray bursts, has already proven successful. The hardware setup, software system, data taking procedures, and first analysis results are described in this paper.

  13. Staircase and saw-tooth field emission steps from nanopatterned n-type GaSb surfaces

    SciTech Connect (OSTI)

    Kildemo, M.; Levinsen, Y. Inntjore; Le Roy, S.; Soenderga ring rd, E. [Department of Physics, Norwegian University of Science and Technology (NTNU), NO-7491 Trondlieim (Norway); Department of Physics, Norwegian University of Science and Technology (NTNU), NO-7491 Trondlieim, Norway and AB CERN, CH- 1211 Geneva 23 (Switzerland); Laboratoire Surface du Verre et Interfaces, UMR 125 Unite Mixte de Recherche CNRS/Saint-Gobain Laboratoire, 39 Quai Lucien Lefranc, F-93303 Aubervilliers Cedex (France)

    2009-09-15T23:59:59.000Z

    High resolution field emission experiments from nanopatterned GaSb surfaces consisting of densely packed nanocones prepared by low ion-beam-energy sputtering are presented. Both uncovered and metal-covered nanopatterned surfaces were studied. Surprisingly, the field emission takes place by regular steps in the field emitted current. Depending on the field, the steps are either regular, flat, plateaus, or saw-tooth shaped. To the author's knowledge, this is the first time that such results have been reported. Each discrete jump in the field emission may be understood in terms of resonant tunneling through an extended surface space charge region in an n-type, high aspect ratio, single GaSb nanocone. The staircase shape may be understood from the spatial distribution of the aspect ratio of the cones.

  14. Effect of antimony on the deep-level traps in GaInNAsSb thin films

    SciTech Connect (OSTI)

    Islam, Muhammad Monirul, E-mail: islam.monir.ke@u.tsukuba.ac.jp; Miyashita, Naoya; Ahsan, Nazmul; Okada, Yoshitaka [Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, 4-6-1 Komaba, Meguro ku, Tokyo 153-8904 (Japan); Sakurai, Takeaki; Akimoto, Katsuhiro [Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan)

    2014-09-15T23:59:59.000Z

    Admittance spectroscopy has been performed to investigate the effect of antimony (Sb) on GaInNAs material in relation to the deep-level defects in this material. Two electron traps, E1 and E2 at an energy level 0.12 and 0.41?eV below the conduction band (E{sub C}), respectively, were found in undoped GaInNAs. Bias-voltage dependent admittance confirmed that E1 is an interface-type defect being spatially localized at the GaInNAs/GaAs interface, while E2 is a bulk-type defect located around mid-gap of GaInNAs layer. Introduction of Sb improved the material quality which was evident from the reduction of both the interface and bulk-type defects.

  15. Methods for chemical recovery of non-carrier-added radioactive tin from irradiated intermetallic Ti-Sb targets

    DOE Patents [OSTI]

    Lapshina, Elena V. (Troitsk, RU); Zhuikov, Boris L. (Troitsk, RU); Srivastava, Suresh C. (Setauket, NY); Ermolaev, Stanislav V. (Obninsk, RU); Togaeva, Natalia R. (Obninsk, RU)

    2012-01-17T23:59:59.000Z

    The invention provides a method of chemical recovery of no-carrier-added radioactive tin (NCA radiotin) from intermetallide TiSb irradiated with accelerated charged particles. An irradiated sample of TiSb can be dissolved in acidic solutions. Antimony can be removed from the solution by extraction with dibutyl ether. Titanium in the form of peroxide can be separated from tin using chromatography on strong anion-exchange resin. In another embodiment NCA radiotin can be separated from iodide solution containing titanium by extraction with benzene, toluene or chloroform. NCA radiotin can be finally purified from the remaining antimony and other impurities using chromatography on silica gel. NCA tin-117m can be obtained from this process. NCA tin-117m can be used for labeling organic compounds and biological objects to be applied in medicine for imaging and therapy of various diseases.

  16. HEATING THE ATMOSPHERE ABOVE SUNSPOTS

    E-Print Network [OSTI]

    Rucklidge, Alastair

    become fragmented and twisted, and where they generate the necessary energy to heat the solar coronaHEATING THE ATMOSPHERE ABOVE SUNSPOTS David Alexander and Neal E. Hurlburt Lockheed Martin Solar, University of Cambridge, Cambridge, CB3 9EW, UK Abstract We present our results of a hybrid model of sunspots

  17. Space Science: Atmosphere Thermal Structure

    E-Print Network [OSTI]

    Johnson, Robert E.

    Space Science: Atmosphere Part -2 Thermal Structure Review tropospheres Absorption of Radiation Adiabatic Lapse Rate ~ 9 K/km Slightly smaller than our estimate Pressure ~3000ft under ocean surface thickness (positive up) is the solar zenith angle Fs is the solar energy flux at frequency (when

  18. The effects of the initial stages of native-oxide formation on the surface properties of GaSb (001)

    SciTech Connect (OSTI)

    Bermudez, V. M. [Electronics Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2013-07-14T23:59:59.000Z

    Atomically clean surfaces of n-type GaSb (001) have been prepared by a combination of ex-situ wet-chemical treatment in HCl and in-situ annealing in a flux of H atoms in ultra-high vacuum (UHV). The surfaces are exposed to 'excited' O{sub 2} and studied using primarily x-ray photoelectron spectroscopy. Low O{sub 2} exposures, up to {approx}3 Multiplication-Sign 10{sup 3} Langmuirs (L), result in a partial passivation of electrically active defects as shown by a decrease in upward band bending. Adsorption of O{sub 2} in this exposure range appears to form mainly Ga{sup +1} sites, with little or no indication of Ga{sup +3}, and saturates at an O coverage of {approx}0.2-0.3 monolayers. For exposures of {approx}10{sup 4} L or higher, oxidation occurs through insertion into Ga-Sb bonds as indicated by the onset of Ga{sup +3} as well as of Sb{sup +4} and/or Sb{sup +5} together with the appearance of an O 1s feature. Defects resulting from this process cause a reversal of the band-bending change seen for smaller exposures. Data obtained for the composition of a native oxide formed in situ in UHV are compared with those for a 'practical' surface produced by processing under ambient conditions. These results suggest an optimum procedure for forming a Ga{sub 2}O{sub 3} layer prior to the growth by atomic layer deposition of an Al{sub 2}O{sub 3} layer.

  19. Abstract KeLP \\Lambda S.B. Baden y , P. Colella z , D. Shalit y , B. Van

    E-Print Network [OSTI]

    Baden, Scott B.

    ``paper'' 2000/12/12 page 1 i i i i i i i i Abstract KeLP \\Lambda S.B. Baden y , P. Colella z , D. The resultant infrastructure, called KeLP \\Lambda , has been applied to a variety of applications including­ tured adaptive refinement for ab­initio molecular dynamics [13]. A distinguishing feature of KeLP

  20. Electron interactions and Dirac fermions in graphene-Ge{sub 2}Sb{sub 2}Te{sub 5} superlattices

    SciTech Connect (OSTI)

    Sa, Baisheng [College of Materials, and Collaborative Innovation Center of Chemistry for Energy Materials, Xiamen University, Xiamen 361005 (China); Sun, Zhimei, E-mail: zmsun@buaa.edu.cn [School of Materials Science and Engineering, and Center for Integrated Computational Materials Engineering, International Research Institute for Multidisciplinary Science, Beihang University, Beijing 100191 (China)

    2014-06-21T23:59:59.000Z

    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.

  1. Argon-ion-induced formation of nanoporous GaSb layer: Microstructure, infrared luminescence, and vibrational properties

    SciTech Connect (OSTI)

    Datta, D. P.; Som, T., E-mail: tsom@iopb.res.in [SUNAG Laboratory, Institute of Physics, Bhubaneswar, Odisha 751 005 (India); Kanjilal, A. [Department of Physics, Shiv Nadar University, Uttar Pradesh 201 314 (India); Satpati, B. [Surface Physics and Material Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India); Dhara, S. [Surface and Nanoscience Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Das, T. D. [Department of Electronic Science, University of Calcutta, APC Road, Kolkata 700 009 (India); Kanjilal, D. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India)

    2014-07-21T23:59:59.000Z

    Room temperature implantation of 60?keV Ar{sup +}-ions in GaSb to the fluences of 7?×?10{sup 16} to 3?×?10{sup 18} ions cm{sup ?2} is carried out at two incidence angles, viz 0° and 60°, leading to formation of a nanoporous layer. As the ion fluence increases, patches grow on the porous layer under normal ion implantation, whereas the porous layer gradually becomes embedded under a rough top surface for oblique incidence of ions. Grazing incidence x-ray diffraction and cross-sectional transmission electron microscopy studies reveal the existence of nanocrystallites embedded in the ion-beam amorphized GaSb matrix up to the highest fluence used in our experiment. Oxidation of the nanoporous layers becomes obvious from x-ray photoelectron spectroscopy and Raman mapping. The correlation of ion-beam induced structural modification with photoluminescence signals in the infrared region has further been studied, showing defect induced emission of additional peaks near the band edge of GaSb.

  2. Superconductivity, magnetic order, and quadrupolar order in the filled skutterudite system Pr 1 ? x Nd x Os 4 Sb 12

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

    Ho, P.-C.; Yanagisawa, T.; Yuhasz, W. M.; Dooraghi, A. A.; Robinson, C. C.; Butch, N. P.; Baumbach, R. E.; Maple, M. B.

    2011-01-01T23:59:59.000Z

    Superconductivity, magnetic order, and the high field ordered phase have been investigated in the filled skutterudite system Pr1-xNdxOs?Sb?? as a function of composition x in magnetic fields up to 9 T and at temperatures between 50 mK and 10 K. Electrical resistivity measurements indicate that the high field ordered phase, which has been identified with antiferroquadruoplar order, persists to x ~ 0.5. The superconducting critical temperature Tc of PrOs?Sb?? is depressed linearly with Nd concentration to x ~ 0.55, whereas the Curie temperature TFM of NdOs?Sb?? is depressed linearly with Pr composition to (1-x) ~ 0.45. In the superconducting region, the upper critical field Hc2(x,0) is depressed quadratically with x in the range 0 c2(x,0) appears to be a result of pair breaking caused by the applied magnetic field and the exchange field associated with the polarization of the Nd magnetic moments in the superconducting state. From magnetic susceptibility measurements, the correlations between the Nd moments in the superconducting state appear to change from ferromagnetic in the range 0.3 ? x ? 0.6 to antiferromagnetic in the range 0 c2(x,0) with x.

  3. 60 keV Ar{sup +}-ion induced modification of microstructural, compositional, and vibrational properties of InSb

    SciTech Connect (OSTI)

    Datta, D. P.; Garg, S. K.; Som, T., E-mail: tsom@iopb.res.in [SUNAG Laboratory, Institute of Physics, Bhubaneswar, Odisha 751005 (India); Satpati, B. [Surface Physics and Materials Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Sahoo, P. K. [School of Physical Sciences, National Institute of Science Education and Research, Bhubaneswar 751005, Odisha (India); Kanjilal, A. [Department of Physics, Shiv Nadar University, Uttar Pradesh 203207 (India); Dhara, S. [Surface and Nanoscience Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Kanjilal, D. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2014-10-14T23:59:59.000Z

    Room temperature irradiation of InSb(111) by 60?keV Ar{sup +}-ions at normal (0°) and oblique (60°) angles of incidence led to the formation of nanoporous structure in the high fluence regime of 1?×?10{sup 17} to 3?×?10{sup 18} ions cm{sup ?2}. While a porous layer comprising of a network of interconnected nanofibers was generated by normal ion incidence, evolution of plate-like structures was observed for obliquely incident ions. Systematic studies of composition and structure using energy dispersive x-ray spectroscopy, Raman spectroscopy, x-ray photoelectron spectroscopy, Raman mapping, grazing incidence x-ray diffraction, and cross-sectional transmission electron microscopy revealed a high degree of oxidation of the ion-induced microstructures with the presence of In{sub 2}O{sub 3} and Sb{sub 2}O{sub 3} phases and presence of nanocrystallites within the nanoporous structures. The observed structural evolution was understood in terms of processes driven by ion-induced defect accumulation within InSb.

  4. Adaptive Filter Techniques for Optical Beam Jitter Control Michael J. Beerer+

    E-Print Network [OSTI]

    Adaptive Filter Techniques for Optical Beam Jitter Control Michael J. Beerer+ , Hyungjoo Yoon beam jitter using a fast-steering mirror. Adaptive filter controllers using Filtered-X least mean jitter include mechanical vibrations on the optical platform (narrowband) and atmospheric turbulence

  5. SURFACE NONLINEAR OPTICS

    E-Print Network [OSTI]

    Shen, Y.R.

    2010-01-01T23:59:59.000Z

    B. de Castro, and Y. R. Shen, Optics Lett. i, 393 See, for3, 1980 SURFACE NONLINEAR OPTICS Y.R. Shen, C.K. Chen, andde Janiero SURFRACE NONLINEAR OPTICS Y. R. Shen, C. K. Chen,

  6. NONLINEAR OPTICS AT INTERFACES

    E-Print Network [OSTI]

    Chen, Chenson K.

    2010-01-01T23:59:59.000Z

    N. Bloembergen, Nonlinear Optics (W. A. Benjamin, 1977) p.Research Division NONLINEAR OPTICS AT INTERFACES Chenson K.ED LBL-12084 NONLINEAR OPTICS AT INTERFACES Chenson K. Chen

  7. The SLS optics beamline

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    The SLS Optics Beamline U. Flechsig ? , R. Abela ? , R.in the ?eld of x-ray optics and synchrotron radiation in-radiation, beamline optics, channel cut monochromator,

  8. Optical manifold

    DOE Patents [OSTI]

    Falicoff, Waqidi; Chaves, Julio C.; Minano, Juan Carlos; Benitez, Pablo; Dross, Oliver; Parkyn, Jr., William A.

    2010-02-23T23:59:59.000Z

    Optical systems are described that have at least one source of a beam of blue light with divergence under 15.degree.. A phosphor emits yellow light when excited by the blue light. A collimator is disposed with the phosphor and forms a yellow beam with divergence under 15.degree.. A dichroic filter is positioned to transmit the beam of blue light to the phosphor and to reflect the beam of yellow light to an exit aperture. In different embodiments, the beams of blue and yellow light are incident upon said filter with central angles of 15.degree., 22.degree., and 45.degree.. The filter may reflect all of one polarization and part of the other polarization, and a polarization rotating retroreflector may then be provided to return the unreflected light to the filter.

  9. Optical absorption measurement system

    DOE Patents [OSTI]

    Draggoo, Vaughn G. (Livermore, CA); Morton, Richard G. (San Diego, CA); Sawicki, Richard H. (Pleasanton, CA); Bissinger, Horst D. (Livermore, CA)

    1989-01-01T23:59:59.000Z

    The system of the present invention contemplates a non-intrusive method for measuring the temperature rise of optical elements under high laser power optical loading to determine the absorption coefficient. The method comprises irradiating the optical element with a high average power laser beam, viewing the optical element with an infrared camera to determine the temperature across the optical element and calculating the absorption of the optical element from the temperature.

  10. Images reveal that atmospheric particles can undergo liquid-liquid phase separations

    SciTech Connect (OSTI)

    You, Yuan; Renbaum-Wolff, Lindsay; Carreras-Sospedra, Marc; Hanna, Sarah; Hiranuma, Naruki; Kamal, Saeid; Smith, Mackenzie L.; Zhang, Xiaolu; Weber, Rodney; Shilling, John E.; Dabdub, Donald; Martin, Scot T.; Bertram, Allan K.

    2012-07-30T23:59:59.000Z

    A large fraction of submicron atmospheric particles contains both organic material and inorganic salts. As the relative humidity cycles in the atmosphere, these mixed particles can undergo a range of phase transitions, possibly including liquid-liquid phase separation. If liquid-liquid phase separation occurs, the gas-particle partitioning of atmospheric semi-volatile organic compounds, the scattering and absorption of solar radiation, and the uptake of reactive gas species on atmospheric particles will be affected, with important implications for climate predictions. The actual occurrence of these types of phase transitions within individual atmospheric particles has been considered uncertain, in large part because of the absence of observations for real-world samples. Here, using optical and fluorescence microscopy, we observe the coexistence of two non-crystalline phases in particles generated from real-world samples collected on multiple days in Atlanta, Georgia, and in particles generated in the laboratory using atmospheric conditions. These results reveal that atmospheric particles can undergo liquid-liquid phase separations. Using a box model, we show that liquid-liquid phase separation can result in increased concentrations of gas-phase NO3 and N2O5 in the Atlanta region, due to decreased particle uptake of N2O5.

  11. Quantum efficiency investigations of type-II InAs/GaSb midwave infrared superlattice photodetectors

    SciTech Connect (OSTI)

    Giard, E., E-mail: edouard.giard@onera.fr; Ribet-Mohamed, I.; Jaeck, J.; Viale, T.; Haïdar, R. [ONERA, DOTA, Chemin de la Hunière, 91761 Palaiseau Cedex (France); Taalat, R.; Delmas, M.; Rodriguez, J.-B.; Christol, P. [Institut d'Electronique du Sud, UMR-CNRS 5214, Université Montpellier 2, Place Eugène Bataillon, 34095 Montpellier Cedex 5 (France); Steveler, E.; Bardou, N. [Laboratoire de Photonique et de Nanostructures (LPN-CNRS), Route de Nozay, 91460 Marcoussis (France); Boulard, F. [CEA, LETI, MINATEC Campus, 17 Avenue des martyrs, 38054 Grenoble (France)

    2014-07-28T23:59:59.000Z

    We present in this paper a comparison between different type-II InAs/GaSb superlattice (T2SL) photodiodes and focal plane array (FPA) in the mid-wavelength infrared domain to understand which phenomenon drives the performances of the T2SL structure in terms of quantum efficiency (QE). Our measurements on test photodiodes suggest low minority carrier diffusion length in the “InAs-rich” design, which penalizes carriers' collection in this structure for low bias voltage and front side illumination. This analysis is completed by a comparison of the experimental data with a fully analytic model, which allows to infer a hole diffusion length shorter than 100?nm. In addition, measurements on a FPA with backside illumination are finally presented. Results show an average QE in the 3–4.7 ?m window equal to 42% for U{sub bias}?=??0.1?V, 77?K operating temperature and no anti-reflection coating. These measurements, completed by modulation transfer function and noise measurements, reveal that the InAs-rich design, despite a low hole diffusion length, is promising for high performance infrared imaging applications.

  12. Activity of the kinesin spindle protein inhibitor ispinesib (SB-715992) in models of breast cancer

    SciTech Connect (OSTI)

    Purcell, James W; Davis, Jefferson; Reddy, Mamatha; Martin, Shamra; Samayoa, Kimberly; Vo, Hung; Thomsen, Karen; Bean, Peter; Kuo, Wen Lin; Ziyad, Safiyyah; Billig, Jessica; Feiler, Heidi S; Gray, Joe W; Wood, Kenneth W; Cases, Sylvaine

    2009-06-10T23:59:59.000Z

    Ispinesib (SB-715992) is a potent inhibitor of kinesin spindle protein (KSP), a kinesin motor protein essential for the formation of a bipolar mitotic spindle and cell cycle progression through mitosis. Clinical studies of ispinesib have demonstrated a 9% response rate in patients with locally advanced or metastatic breast cancer, and a favorable safety profile without significant neurotoxicities, gastrointestinal toxicities or hair loss. To better understand the potential of ispinesib in the treatment of breast cancer we explored the activity of ispinesib alone and in combination several therapies approved for the treatment of breast cancer. We measured the ispinesib sensitivity and pharmacodynamic response of breast cancer cell lines representative of various subtypes in vitro and as xenografts in vivo, and tested the ability of ispinesib to enhance the anti-tumor activity of approved therapies. In vitro, ispinesib displayed broad anti-proliferative activity against a panel of 53 breast cell-lines. In vivo, ispinesib produced regressions in each of five breast cancer models, and tumor free survivors in three of these models. The effects of ispinesib treatment on pharmacodynamic markers of mitosis and apoptosis were examined in vitro and in vivo, revealing a greater increase in both mitotic and apoptotic markers in the MDA-MB-468 model than in the less sensitive BT-474 model. In vivo, ispinesib enhanced the anti-tumor activity of trastuzumab, lapatinib, doxorubicin, and capecitabine, and exhibited activity comparable to paclitaxel and ixabepilone. These findings support further clinical exploration of KSP inhibitors for the treatment of breast cancer.

  13. Influence of interstitial Mn on magnetism in room-temperature ferromagnet Mn(1+delta)Sb

    SciTech Connect (OSTI)

    Taylor, Alice E [ORNL; Berlijn, Tom [ORNL; Hahn, Steven E [ORNL; May, Andrew F [ORNL; Williams, Travis J [ORNL; Poudel, Lekhanath N [ORNL; Calder, Stuart A [ORNL; Fishman, Randy Scott [ORNL; Stone, Matthew B [ORNL; Aczel, Adam A [ORNL; Cao, Huibo [ORNL; Lumsden, Mark D [ORNL; Christianson, Andrew D [ORNL

    2015-01-01T23:59:59.000Z

    We report elastic and inelastic neutron scattering measurements of the high-TC ferromagnet Mn(1+delta)Sb. Measurements were performed on a large, TC = 434 K, single crystal with interstitial Mn content of delta=0.13. The neutron diffraction results reveal that the interstitial Mn has a magnetic moment, and that it is aligned antiparallel to the main Mn moment. We perform density functional theory calculations including the interstitial Mn, and find the interstitial to be magnetic in agreement with the diffraction data. The inelastic neutron scattering measurements reveal two features in the magnetic dynamics: i) a spin-wave-like dispersion emanating from ferromagnetic Bragg positions (H K 2n), and ii) a broad, non-dispersive signal centered at forbidden Bragg positions (H K 2n+1). The inelastic spectrum cannot be modeled by simple linear spin-wave theory calculations, and appears to be significantly altered by the presence of the interstitial Mn ions. The results show that the influence of the int

  14. Correction to “Hyperspectral Aerosol Optical Depths from TCAP Flights”

    SciTech Connect (OSTI)

    Shinozuka, Yohei; Johnson, Roy R.; Flynn, Connor J.; Russell, P. B.; Schmid, Beat; Redemann, Jens; Dunagan, Stephen; Kluzek, Celine D.; Hubbe, John M.; Segal-Rosenheimer, Michal; Livingston, J. M.; Eck, T.; Wagener, Richard; Gregory, L.; Chand, Duli; Berg, Larry K.; Rogers, Ray; Ferrare, R. A.; Hair, John; Hostetler, Chris A.; Burton, S. P.

    2014-02-16T23:59:59.000Z

    In the paper “Hyperspectral aerosol optical depths from TCAP flights” by Y. Shinozuka et al. (Journal of Geophysical Research: Atmospheres, 118, doi:10.1002/2013JD020596, 2013), Tables 1 and 2 were published with the column heads out of order. Tables 1 and 2 are published correctly here. The publisher regrets the error.

  15. Sulfuryl fluoride in the global atmosphere

    E-Print Network [OSTI]

    Muhle, J.

    The first calibrated high-frequency, high-precision, in situ atmospheric and archived air measurements of the fumigant sulfuryl fluoride (SO[subscript 2]F[subscript 2]) have been made as part of the Advanced Global Atmospheric ...

  16. ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. (2012)

    E-Print Network [OSTI]

    Gerber, Edwin

    2012-01-01T23:59:59.000Z

    ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. (2012) Published online in Wiley Online Library using National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP) concentrations and sea- surface temperatures (SSTs). These integrations enable the relative role of ozone

  17. Evaluation of Optical Magnitude of Deep Space Spacecraft

    E-Print Network [OSTI]

    Liu Wei; Tang Zheng-Hong; Li Yong-Da

    2007-12-10T23:59:59.000Z

    Optical-electric technology can measure the tangential position and velocity of spacecraft. To know the feasibility of the use of optical-electric technology, it is necessary to estimate the magnitude of spacecraft first. Since the spacecrafts are non-self-illumination objects, the estimation formulas of the optical magnitude of spacecraft is constructed according to the radiation theory and the extra-atmospheric radiant emittance of the Sun in the visible light wave band. Taking Chang'e-1 as an example, the magnitude of it in different situations is calculated.

  18. 1997 Atmospheric Chemistry Colloquium for Emerging Senior Scientists

    SciTech Connect (OSTI)

    Paul H. Wine

    1998-11-23T23:59:59.000Z

    DOE's Atmospheric Chemistry Program is providing partial funding for the Atmospheric Chemistry Colloquium for Emerging Senior Scientists (ACCESS) and FY 1997 Gordon Research Conference in Atmospheric Chemistry

  19. atmospheric nitrogen fluorescence: Topics by E-print Network

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

    Websites Summary: Greenhouse Effect and Atmospheric Warming Atmosphere absorbs heat energy A real greenhouse traps heatCh4. Atmosphere and Surface Energy Balances...

  20. atmospheric energy redistribution: Topics by E-print Network

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

    16 Ch4. Atmosphere and Surface Energy Balances Geosciences Websites Summary: Greenhouse Effect and Atmospheric Warming Atmosphere absorbs heat energy A real greenhouse traps...

  1. atmospheric pressure surface: Topics by E-print Network

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

    K. 27 Ch4. Atmosphere and Surface Energy Balances Geosciences Websites Summary: Greenhouse Effect and Atmospheric Warming Atmosphere absorbs heat energy A real greenhouse traps...

  2. Radar range measurements in the atmosphere.

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2013-02-01T23:59:59.000Z

    The earth's atmosphere affects the velocity of propagation of microwave signals. This imparts a range error to radar range measurements that assume the typical simplistic model for propagation velocity. This range error is a function of atmospheric constituents, such as water vapor, as well as the geometry of the radar data collection, notably altitude and range. Models are presented for calculating atmospheric effects on radar range measurements, and compared against more elaborate atmospheric models.

  3. Proof of the Atmospheric Greenhouse Effect

    E-Print Network [OSTI]

    Smith, Arthur P

    2008-01-01T23:59:59.000Z

    A recently advanced argument against the atmospheric greenhouse effect is refuted. A planet without an infrared absorbing atmosphere is mathematically constrained to have an average temperature less than or equal to the effective radiating temperature. Observed parameters for Earth prove that without infrared absorption by the atmosphere, the average temperature of Earth's surface would be at least 33 K lower than what is observed.

  4. Atmospheric Lifetime of Fossil Fuel Carbon Dioxide

    E-Print Network [OSTI]

    Scherer, Norbert F.

    Atmospheric Lifetime of Fossil Fuel Carbon Dioxide David Archer,1 Michael Eby,2 Victor Brovkin,3 released from combustion of fossil fuels equilibrates among the various carbon reservoirs of the atmosphere literature on the atmospheric lifetime of fossil fuel CO2 and its impact on climate, and we present initial

  5. Hydrothermal synthesis and thermoelectric properties of nanostructured Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} compounds

    SciTech Connect (OSTI)

    Zhang, Yanhua [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, No. 30, Xueyuan Road, Beijing 100083 (China) [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, No. 30, Xueyuan Road, Beijing 100083 (China); Academy of Equipment Command and Technology, Beijing 102249 (China); Xu, Guiying [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, No. 30, Xueyuan Road, Beijing 100083 (China)] [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, No. 30, Xueyuan Road, Beijing 100083 (China); Mi, Jianli [Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, DK-8000 Aarhus (Denmark)] [Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, DK-8000 Aarhus (Denmark); Han, Fei; Wang, Ze [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, No. 30, Xueyuan Road, Beijing 100083 (China)] [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, No. 30, Xueyuan Road, Beijing 100083 (China); Ge, Changchun, E-mail: ccge@mater.ustb.edu.cn [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, No. 30, Xueyuan Road, Beijing 100083 (China)] [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, No. 30, Xueyuan Road, Beijing 100083 (China)

    2011-05-15T23:59:59.000Z

    Research highlights: {yields} Single-phase Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} powders have been synthesized by a hydrothermal route. {yields} Hexagonal Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} naosheets due to the anisotropic growth of the crystals. {yields} The temperature gradients lead to directional arrangement nanosheet-agglomerates. {yields} Nanosheet-agglomerates are beneficial for improving the TE property of products. {yields} A maximum figure of merit of 0.86 is achieved at about 100 {sup o}C. -- Abstract: Single-phase Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} compounds have been prepared by hydrothermal synthesis at 150 {sup o}C for 24 h using SbCl{sub 3}, BiCl{sub 3} and tellurium powder as precursors. X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) have been applied to analyze the phase distributions, microstructures and grain sizes of the as-grown Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} products. It is found that the hydrothermally synthesized Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} nanopowders have a morphology dominated by irregular hexagonal sheets due to the anisotropic growth of the crystals. The Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} nanosheets are parallelly stacked in certain direction to form sheet-agglomerates attribute to the temperature gradients in the solution.

  6. Atmospheric-pressure plasma jet

    DOE Patents [OSTI]

    Selwyn, Gary S. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    Atmospheric-pressure plasma jet. A .gamma.-mode, resonant-cavity plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two concentric cylindrical electrodes are employed to generate a plasma in the annular region therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly shaping the rf-powered electrode. Because of the atmospheric pressure operation, no ions survive for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike low-pressure plasma sources and conventional plasma processing methods.

  7. LABORATORY I: GEOMETRIC OPTICS

    E-Print Network [OSTI]

    Minnesota, University of

    Lab I - 1 LABORATORY I: GEOMETRIC OPTICS In this lab, you will solve several problems related to the formation of optical images. Most of us have a great deal of experience with the formation of optical images this laboratory, you should be able to: · Describe features of real optical systems in terms of ray diagrams

  8. Optical XOR gate

    DOE Patents [OSTI]

    Vawter, G. Allen

    2013-11-12T23:59:59.000Z

    An optical XOR gate is formed as a photonic integrated circuit (PIC) from two sets of optical waveguide devices on a substrate, with each set of the optical waveguide devices including an electroabsorption modulator electrically connected in series with a waveguide photodetector. The optical XOR gate utilizes two digital optical inputs to generate an XOR function digital optical output. The optical XOR gate can be formed from III-V compound semiconductor layers which are epitaxially deposited on a III-V compound semiconductor substrate, and operates at a wavelength in the range of 0.8-2.0 .mu.m.

  9. The effects of the chemical composition and strain on the electronic properties of GaSb/InAs core-shell nanowires

    SciTech Connect (OSTI)

    Ning, Feng; Wang, Dan; Tang, Li-Ming, E-mail: lmtang@hnu.edu.cn; Zhang, Yong; Chen, Ke-Qiu, E-mail: keqiuchen@hnu.edu.cn [Department of Applied Physics, Hunan University, Changsha 410082 (China)

    2014-09-07T23:59:59.000Z

    The effects of the chemical composition and strain on the electronic properties of [111] zinc-blende (ZB) and [0001] wurtzite (WZ) GaSb/InAs core-shell nanowires (NWs) with different core diameters and shell thicknesses are studied using first-principles methods. The band structures of the [111] ZB GaSb/InAs core-shell NWs underwent a noticeable type-I/II band alignment transition, associated with a direct-to-indirect band gap transition under a compressive uniaxial strain. The band structures of the [0001] WZ GaSb/InAs core-shell NWs preserved the direct band gap under either compressive or tensile uniaxial strains. In addition, the band gaps and the effective masses of the carriers could be tuned by their composition. For the core-shell NWs with a fixed GaSb-core size, the band gaps decreased linearly with an increasing InAs-shell thickness, caused by the significant downshift of the conduction bands. For the [111] ZB GaSb/InAs core-shell NWs, the calculated effective masses indicated that the transport properties could be changed from hole-dominated conduction to electron-dominated conduction by changing the InAs-shell thickness.

  10. Highly tunable electron transport in epitaxial topological insulator (Bi{sub 1-x}Sb{sub x}){sub 2}Te{sub 3} thin films

    SciTech Connect (OSTI)

    He Xiaoyue; Guan Tong; Wang Xiuxia; Feng Baojie; Cheng Peng; Chen Lan; Li Yongqing; Wu Kehui [Institute of Physics, Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2012-09-17T23:59:59.000Z

    Atomically smooth, single crystalline (Bi{sub 1-x}Sb{sub x}){sub 2}Te{sub 3} films have been grown on SrTiO{sub 3}(111) substrates by molecular beam epitaxy. A full range of Sb-Bi compositions have been studied in order to obtain the lowest possible bulk conductivity. For the samples with optimized Sb compositions (x=0.5{+-}0.1), the carrier type can be tuned from n-type to p-type across the whole thickness with the help of a back-gate. Linear magnetoresistance has been observed at gate voltages close to the maximum in the longitudinal resistance of a (Bi{sub 0.5}Sb{sub 0.5}){sub 2}Te{sub 3} sample. These highly tunable (Bi{sub 1-x}Sb{sub x}){sub 2}Te{sub 3} thin films provide an excellent platform to explore the intrinsic transport properties of the three-dimensional topological insulators.

  11. Interfacial structure, bonding and composition of InAs and GaSb thin films determined using coherent Bragg rod analysis.

    SciTech Connect (OSTI)

    Cionca, C.; Walko, D. A.; Yacoby, Y.; Dorin, C.; Millunchick, J. M.; Clarke, R.; X-Ray Science Division; Univ. of Michigan; Hebrew Univ.

    2007-01-01T23:59:59.000Z

    We have used Bragg rod x-ray diffraction combined with a direct method of phase retrieval to extract atomic resolution electron-density maps of a complementary series of heteroepitaxial III-V semiconductor samples. From the three-dimensional electron-density maps we derive the monolayer spacings, the chemical compositions, and the characteristics of the bonding for all atomic planes in the film and across the film-substrate interface. InAs films grown on GaSb(001) under two different As conditions (using dimer or tetramer forms) both showed conformal roughness and mixed GaAs/InSb interfacial bonding character. The As tetramer conditions favored InSb bonding at the interface while, in the case of the dimer, the percentages corresponding to GaAs and InSb bonding were equal within the experimental error. The GaSb film grown on InAs(001) displayed significant In and As interdiffusion and had a relatively large fraction of GaAs-like bonds at the interface.

  12. An Infrared Spectral Library for Atmospheric Environmental Monitoring...

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

    An Infrared Spectral Library for Atmospheric Environmental Monitoring. An Infrared Spectral Library for Atmospheric Environmental Monitoring. Abstract: Infrared (IR) spectroscopy...

  13. atmospheric research community: Topics by E-print Network

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

    University Corporation for Atmospheric Research Geosciences Websites Summary: University Corporation for Atmospheric Research CIGNA DENTAL PREFERRED PROVIDER INSURANCE EFFECTIVE...

  14. Emission properties of heterostructures with a (GaAsSb-InGaAs)/GaAs bilayer quantum well

    SciTech Connect (OSTI)

    Zvonkov, B. N.; Nekorkin, S. M.; Vikhrova, O. V.; Dikareva, N. V., E-mail: dikareva@nifti.unn.ru [Nizhni Novgorod State University, Physical-Technical Research Institute (Russian Federation)

    2013-09-15T23:59:59.000Z

    The specific features of the emission characteristics of GaAs-based heterostructures with a GaAs{sub 1-x}Sb{sub x}-In{sub y}Ga{sub 1-y}As bilayer quantum well are studied. The heterostructures are grown by metal-organic chemical vapor deposition (MOCVD). With an analysis of previously reported data on the MOCVD growth process taken into account, the temperature range (560-580 Degree-Sign C), the relation between the fluxes emitted by the sources of Group-V and -III elements ( Less-Than-Or-Equivalent-To 1), and the order of layer growth for the production of the active region of a GaAs/InGaP laser heterostructure are determined experimentally. The active region is a GaAs{sub 0.75}Sb{sub 0.25}-In{sub 0.2}Ga{sub 0.8}As bilayer quantum well. For the structure, a 1075-nm electroluminescence signal attributed to indirect transitions between the valence band of the GaAs{sub 0.75}Sb{sub 0.25} layer and the conduction band of the In{sub 0.2}Ga{sub 0.8}As layer is observed. An increase in the continuous-wave pump current yields a decrease in the 1075-nm emission intensity and initiates stable lasing at a wavelength of 1022 nm at a threshold current density of 1.4 kA cm{sup -2} at room temperature. Lasing occurs at transitions direct in coordinate space.

  15. Pulse atmospheric fluidized bed combustion

    SciTech Connect (OSTI)

    Not Available

    1989-03-01T23:59:59.000Z

    The overall objective of the program is the development of a pulsed atmospheric fluidized-bed combustion (PAFBC) technology to burn coal and to provide heat and steam to commercial, institutional, and small industrial applications at a reasonable price in an environmentally acceptable manner. During this reporting period, a total of eight shakedown and debugging coal combustion tests were performed in the AFBC. A start-up procedure was established, system improvements implemented, and preliminary material and heat balances made based on these tests. The pulse combustor for the AFBC system was fabricated and installed and a series of tests was conducted on the system. 17 figs., 5 tabs.

  16. NETL SOFC: Atmospheric Pressure Systems

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Saleshttp://www.fnal.gov/directorate/nalcal/nalcal02_07_05_files/nalcal.gif Directorate -AdvancedMIRTBD525AdaptingWaterTerryAtmospheric

  17. Optical and mechanical behavior of the optical fiber infrasound sensor

    E-Print Network [OSTI]

    DeWolf, Scott

    2009-01-01T23:59:59.000Z

    1.2 The Optical Fiber Infrasound Sensor . . . . . . .Fiber Infrasound Sensor Optical fibers are well known forSchnidrig. An optical fiber infrasound sensor: A new lower

  18. Transport properties of partially-filled Ce{sub y}Co{sub 4}Sb{sub 12}

    SciTech Connect (OSTI)

    Uher, C.; Chen, B.; Hu, S.; Morelli, D.T.; Meisner, G.P.

    1997-07-01T23:59:59.000Z

    The authors have investigated the magnetic and transport properties of Ce{sub y}Co{sub 4}Sb{sub 12} filled skutterudites with the filling fraction y {le} 0.1. These compounds are n-type materials that develop a magnetic moment upon the presence of trivalent cerium. Cerium has a strong influence on all transport properties and even in small amounts it drastically reduces the lattice thermal conductivity. The resulting figures of merit are comparable to the values established previously for the p-type filled skutterudites.

  19. From the atmosphere to the circumstellar environment in cool evolved stars

    E-Print Network [OSTI]

    Wittkowski, Markus

    2015-01-01T23:59:59.000Z

    We discuss and illustrate contributions that optical interferometry has made on our current understanding of cool evolved stars. We include red giant branch (RGB) stars, asymptotic giant branch (AGB) stars, and red supergiants (RSGs). Studies using optical interferometry from visual to mid-infrared wavelengths have greatly increased our knowledge of their atmospheres, extended molecular shells, dust formation, and winds. These processes and the morphology of the circumstellar environment are important for the further evolution of these stars toward planetary nebulae (PNe) and core-collapse supernovae (SNe), and for the return of material to the interstellar medium.

  20. Low-temperature transport properties of the mixed-valence semiconductor Ru{sub 0.5}Pd{sub 0.5}Sb{sub 3}

    SciTech Connect (OSTI)

    Nolas, G.S. [Research and Development Division, Marlow Industries, Dallas, Texas 75238 (United States)] [Research and Development Division, Marlow Industries, Dallas, Texas 75238 (United States); Harris, V.G.; Tritt, T.M. [Materials Physics Branch, Naval Research Laboratory, Washington, DC 20375 (United States)] [Materials Physics Branch, Naval Research Laboratory, Washington, DC 20375 (United States); Slack, G.A. [Department of Physics, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)] [Department of Physics, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    1996-12-01T23:59:59.000Z

    We have measured the transport properties of Ru{sub 0.5}Pd{sub 0.5}Sb{sub 3} from 300 down to 4 K and compared them to those of the binary-skutterudite antimonides. In particular, the lattice thermal conductivity of this compound is substantially lower than that of CoSb{sub 3} and IrSb{sub 3}. This is attributed to the mixed-valency of ruthenium in this compound. Using near-edge extended absorption fine structure analysis, it is observed that ruthenium in this compound is in the Ru{sup 4+}- and Ru{sup 2+}-valence states in approximately equal proportions. The potential for thermoelectric applications of this material is also discussed. {copyright} {ital 1996 American Institute of Physics.}

  1. Latching micro optical switch

    DOE Patents [OSTI]

    Garcia, Ernest J; Polosky, Marc A

    2013-05-21T23:59:59.000Z

    An optical switch reliably maintains its on or off state even when subjected to environments where the switch is bumped or otherwise moved. In addition, the optical switch maintains its on or off state indefinitely without requiring external power. External power is used only to transition the switch from one state to the other. The optical switch is configured with a fixed optical fiber and a movable optical fiber. The movable optical fiber is guided by various actuators in conjunction with a latching mechanism that configure the switch in one position that corresponds to the on state and in another position that corresponds to the off state.

  2. No. 16 ISSN 10278389 March 2012 The Southern African Large Telescope (Courtesy: S.B. Potter)

    E-Print Network [OSTI]

    Jarrett, Thomas H.

    @aol.com P.M. Okouma Gabon okouma@hotmail.com A.I. Ibrahim Egypt alaa@milkyway.gsfc.nasa.gov L. Kebede-East and Africa. In partic- ular, the completion of HESS (the High Energy Stereoscopic System, in Namibia-class observational capability from ultra-high energy gamma-rays, through optical/near-IR to radio wave- lengths

  3. Sandia National Laboratories: Quantum Optics

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

    ClimateQuantum Optics Quantum Optics videobanner Quantum Optics with a Single Semiconductor Quantum Dot Speaker: Weng Chow, EFRC Scientist Date: September 14, 2011 Event:...

  4. Atmospheric neutrino flux at INO site

    SciTech Connect (OSTI)

    Honda, Morihiro [Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa, Chiba 277-8582 (Japan)

    2011-11-23T23:59:59.000Z

    To illustrate the calculation of the atmospheric neutrino flux, we briefly explain our calculation scheme and important components, such as primary cosmic ray spectra, interaction model, and geomagnetic model. Then, we calculate the atmospheric neutrino flux at INO site in our calculation scheme. We compare the calculated atmospheric neutrino fluxes predicted at INO with those at other major neutrino detector sites, especially that at SK site.

  5. Active optical zoom system

    DOE Patents [OSTI]

    Wick, David V.

    2005-12-20T23:59:59.000Z

    An active optical zoom system changes the magnification (or effective focal length) of an optical imaging system by utilizing two or more active optics in a conventional optical system. The system can create relatively large changes in system magnification with very small changes in the focal lengths of individual active elements by leveraging the optical power of the conventional optical elements (e.g., passive lenses and mirrors) surrounding the active optics. The active optics serve primarily as variable focal-length lenses or mirrors, although adding other aberrations enables increased utility. The active optics can either be LC SLMs, used in a transmissive optical zoom system, or DMs, used in a reflective optical zoom system. By appropriately designing the optical system, the variable focal-length lenses or mirrors can provide the flexibility necessary to change the overall system focal length (i.e., effective focal length), and therefore magnification, that is normally accomplished with mechanical motion in conventional zoom lenses. The active optics can provide additional flexibility by allowing magnification to occur anywhere within the FOV of the system, not just on-axis as in a conventional system.

  6. Found: The missing blue opacity in atmosphere models of cool hydrogen white dwarfs

    E-Print Network [OSTI]

    P. M. Kowalski; D. Saumon

    2006-09-26T23:59:59.000Z

    We investigate the importance of the far red wing of the Lyman $ \\alpha$ line of hydrogen in the atmospheres of cool white dwarfs of pure hydrogen composition. We find that this absorption process dominates all important sources of opacity in the blue part of the optical spectrum of these stars. Our successful fits to the spectra of cool DA/DC white dwarfs indicate that the far red wing of the $\\rm Ly \\alpha$ line is the source of opacity that had been missing in the models. The observed sequence of cool white dwarfs in color-color diagrams is very well reproduced by our new pure hydrogen atmosphere models, suggesting that the atmospheric composition of the coolest DC white dwarfs must be revisited.

  7. An advanced open-path atmospheric pollution monitor for large areas

    SciTech Connect (OSTI)

    Taylor, L.

    1995-12-31T23:59:59.000Z

    Large amounts of toxic waste materials, generated in manufacturing fuel for nuclear reactors, are stored in tanks buried over large areas at DOE sites. Flammable and hazardous gases are continually generated by chemical reactions in the waste materials. To prevent explosive concentrations of these gases, the gases are automatically vented to the atmosphere when the pressure exceeds a preset value. Real-time monitoring of the atmosphere above the tanks with automatic alarming is needed to prevent exposing workers to unsafe conditions when venting occurs. This project is to design, develop, and test an atmospheric pollution monitor which can measure concentrations of DOE-specified and EPA-specified hazardous gases over ranges as long as 4km. A CO{sub 2} laser to measure absorption spectra and to determine the distance over which the measurements are made, is combined with an acousto-optic tunable filter (AOTF) to measure thermal emission spectra.

  8. Toxicity of atmospheric aerosols on marine phytoplankton

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    metals added from these aerosols to the bioassay incubationsreleased to seawater from the aerosol filters after Author4605 CHEMISTRY Atmospheric aerosol deposition CHEMISTRY

  9. Urban Atmospheres captures a unique, synergistic moment

    E-Print Network [OSTI]

    Paulos, Eric

    Urban Atmospheres captures a unique, synergistic moment ­ expanding urban populations, rapid EDITORS Eric Paulos Intel Research eric@paulos.net Tom Jenkins Royal College of Art thomas

  10. Characterizing orbit uncertainty due to atmospheric uncertainty

    E-Print Network [OSTI]

    Wilkins, Matthew Paul

    2000-01-01T23:59:59.000Z

    is implemented to model errors in the atmospheric density model. This study shows that the Kalman filter computes a believable and more realistic covariance....

  11. Atmospheric Radiation Measurement Climate Research Facility ...

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

    improving our understanding of how clouds and atmospheric moisture interact with solar radiation and the effects of these interactions on climate. Photo courtesy Argonne National...

  12. Physics Potential of Future Atmospheric Neutrino Searches

    E-Print Network [OSTI]

    Thomas Schwetz

    2008-12-12T23:59:59.000Z

    The potential of future high statistics atmospheric neutrino experiments is considered, having in mind currently discussed huge detectors of various technologies (water Cerekov, magnetized iron, liquid Argon). I focus on the possibility to use atmospheric data to determine the octant of $\\theta_{23}$ and the neutrino mass hierarchy. The sensitivity to the $\\theta_{23}$-octant of atmospheric neutrinos is competitive (or even superior) to long-baseline experiments. I discuss the ideal properties of a fictitious atmospheric neutrino detector to determine the neutrino mass hierarchy.

  13. Super-Kamiokande atmospheric neutrino results

    E-Print Network [OSTI]

    Toshiyuki Toshito; the Super-Kamiokande collaboration

    2001-05-14T23:59:59.000Z

    We present atmospheric neutrino results from a 79 kiloton year (1289 days) exposure of the Super-Kamiokande detector. Our data are well explained by $\

  14. Crystallographic analysis of the structure of livingstonite HgSb{sub 4}S{sub 8} from refined data

    SciTech Connect (OSTI)

    Borisov, S. V., E-mail: borisov@che.nsk.su; Pervukhina, N. V.; Magarill, S. A.; Kuratieva, N. V. [Russian Academy of Sciences, Nikolaev Institute of Inorganic Chemistry, Siberian Branch (Russian Federation); Vasil'ev, V. I., E-mail: itret@uiggm.nsc.ru [Russian Academy of Sciences, Institute of Geology and Mineralogy, Siberian Branch (Russian Federation)

    2010-03-15T23:59:59.000Z

    An X-ray diffraction study of mineral livingstonite (HgSb{sub 4}S{sub 8}) from Khaydarkan (Kyrgyzstan) has been performed on a Bruker Nonius X8Apex diffractometer with a 4K CCD detector (R = 0.031). The unit-cell parameters were found to be a = 30.1543(10) A, b = 3.9953(2) A, c = 21.4262(13) A, {beta} = 104.265(1){sup o}, V = 2501.7(2) A{sup 3}, Z = 8, d{sub calcd} = 5.013 g/cm{sup 3}, and sp. gr. A2/a. It was confirmed that livingstonite belongs to rod-layers structures. In one type of layer, two double Sb{sub 2}S{sub 4} chains are bound by disulfide groups [S{sub 2}]{sup 2-} (S-S 2.078(2) A); in the other type, these chains are bound via Hg{sup 2+} cations. A crystallographic analysis confirmed the existence of independent pseudotranslational ordering in the cation and anion matrices, which is characteristic of the lozenge-like structures of sulfides and sulfosalts.

  15. Study of a 1?eV GaNAsSb photovoltaic cell grown on a silicon substrate

    SciTech Connect (OSTI)

    Tan, K. H.; Loke, W. K.; Wicaksono, S.; Li, D.; Leong, Y. R.; Yoon, S. F. [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore)] [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore); Sharma, P.; Milakovich, T.; Bulsara, M. T.; Fitzgerald, E. A. [Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139 (United States)] [Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139 (United States)

    2014-03-10T23:59:59.000Z

    We report the performance of a 1?eV GaNAsSb photovoltaic cell grown on a Si substrate with a SiGe graded buffer grown using molecular beam epitaxy. For comparison, the performance of a similar 1?eV GaN{sub 0.018}As{sub 0.897}Sb{sub 0.085} photovoltaic cell grown on a GaAs substrate was also reported. Both devices were in situ annealed at 700?°C for 5?min, and a significant performance improvement over our previous result was observed. The device on the GaAs substrate showed a low open circuit voltage (V{sub OC}) of 0.42?V and a short circuit current density (J{sub SC}) of 23.4?mA/cm{sup 2} while the device on the Si substrate showed a V{sub OC} of 0.39?V and a J{sub SC} of 21.3?mA/cm{sup 2}. Both devices delivered a quantum efficiency of 50%–55% without any anti-reflection coating.

  16. High bandwidth optical mount

    SciTech Connect (OSTI)

    Bender, D.A.; Kuklo, T.

    1994-11-08T23:59:59.000Z

    An optical mount, which directs a laser beam to a point by controlling the position of a light-transmitting optic, is stiffened so that a lowest resonant frequency of the mount is approximately one kilohertz. The optical mount, which is cylindrically-shaped, positions the optic by individually moving a plurality of carriages which are positioned longitudinally within a sidewall of the mount. The optical mount is stiffened by allowing each carriage, which is attached to the optic, to move only in a direction which is substantially parallel to a center axis of the optic. The carriage is limited to an axial movement by flexures or linear bearings which connect the carriage to the mount. The carriage is moved by a piezoelectric transducer. By limiting the carriage to axial movement, the optic can be kinematically clamped to a carriage. 5 figs.

  17. SEARCH FOR RAYLEIGH SCATTERING IN THE ATMOSPHERE OF GJ1214b

    SciTech Connect (OSTI)

    De Mooij, E. J. W.; Jayawardhana, R. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Brogi, M.; Snellen, I. A. G.; Hoekstra, H.; Otten, G. P. P. L.; Bekkers, D. H.; Haffert, S. Y.; Van Houdt, J. J. [Leiden Observatory, Leiden University, Postbus 9513, 2300-RA, Leiden (Netherlands); De Kok, R. J. [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584-CA, Utrecht (Netherlands); Croll, B., E-mail: demooij@astro.utoronto.ca [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2013-07-10T23:59:59.000Z

    We investigate the atmosphere of GJ1214b, a transiting super-Earth planet with a low mean density, by measuring its transit depth as a function of wavelength in the blue optical portion of the spectrum. It is thought that this planet is either a mini-Neptune, consisting of a rocky core with a thick, hydrogen-rich atmosphere, or a planet with a composition dominated by water. Most observations favor a water-dominated atmosphere with a small scale-height, however, some observations indicate that GJ1214b could have an extended atmosphere with a cloud layer muting the molecular features. In an atmosphere with a large scale-height, Rayleigh scattering at blue wavelengths is likely to cause a measurable increase in the apparent size of the planet toward the blue. We observed the transit of GJ1214b in the B band with the FOcal Reducing Spectrograph at the Very Large Telescope and in the g band with both ACAM on the William Herschel Telescope (WHT) and the Wide Field Camera at the Isaac Newton Telescope (INT). We find a planet-to-star radius ratio in the B band of 0.1162 {+-} 0.0017, and in the g band 0.1180 {+-} 0.0009 and 0.1174 {+-} 0.0017 for the WHT and INT observations, respectively. These optical data do not show significant deviations from previous measurements at longer wavelengths. In fact, a flat transmission spectrum across all wavelengths best describes the combined observations. When atmospheric models are considered, a small scale-height water-dominated model fits the data best.

  18. Response of global soil consumption of atmospheric methane to changes in atmospheric climate and nitrogen deposition

    E-Print Network [OSTI]

    Zhuang, Qianlai

    Soil consumption of atmospheric methane plays an important secondary role in regulating the atmospheric CH4 budget, next to the dominant loss mechanism involving reaction with the hydroxyl radical (OH). Here we used a ...

  19. ''Atomic Optics'': Nonimaging Optics on the Nanoscale

    SciTech Connect (OSTI)

    Roland Winston Joseph O'Gallagher

    2005-01-15T23:59:59.000Z

    This is the final report for a one year close out extension of our basic research program that was established at the University of Chicago more than sixteen years ago to explore and develop the optical sub-discipline that has come to be known as ''nonimaging optics''. This program has been extremely fruitful, having both broadened the range of formalism available for workers in this field and led to the discovery of many new families of optical devices. These devices and techniques have applications wherever the efficient transport and transformation of light distributions are important, in particular in illumination, fiber optics, collection and concentration of sunlight, and the detection of faint light signals in physics and astrophysics. Over the past thirty years, Nonimaging Optics (Welford and Winston, 1989) has brought a fresh approach to the analysis of many problems in classical macro-scale optics. Through the application of phase-space concepts, statistical methods, thermodynamic arguments, etc., many previously established performance limits were able to be broken and many technical surprises with exciting practical applications were discovered. The most recent three-year phase of our long-term continuing program ended in late 2002 and emphasized extending our work in geometrical optics and expanding it to include some interesting questions in physical optics as well as in the new field of statistical optics. This report presents a survey of the basic history and concepts of nonimaging optics and reviews highlights and significant accomplishments over the past fifteen years. This is followed by a more detailed summary of recent research directions and accomplishments during the last three years. This most recent phase was marked by the broadening in scope to include a separate project involving a collaboration with an industrial partner, Science Applications International Corporation (SAIC). This effort was proposed and approved in 1998 and was incorporated into this project (September, 1998) with the required additional funding provided through this already existing grant.

  20. Reflective optical imaging system

    DOE Patents [OSTI]

    Shafer, David R. (Fairfield, CT)

    2000-01-01T23:59:59.000Z

    An optical system compatible with short wavelength (extreme ultraviolet) radiation comprising four reflective elements for projecting a mask image onto a substrate. The four optical elements are characterized in order from object to image as convex, concave, convex and concave mirrors. The optical system is particularly suited for step and scan lithography methods. The invention increases the slit dimensions associated with ringfield scanning optics, improves wafer throughput and allows higher semiconductor device density.

  1. Optical voltage reference

    DOE Patents [OSTI]

    Rankin, R.; Kotter, D.

    1994-04-26T23:59:59.000Z

    An optical voltage reference for providing an alternative to a battery source is described. The optical reference apparatus provides a temperature stable, high precision, isolated voltage reference through the use of optical isolation techniques to eliminate current and impedance coupling errors. Pulse rate frequency modulation is employed to eliminate errors in the optical transmission link while phase-lock feedback is employed to stabilize the frequency to voltage transfer function. 2 figures.

  2. Fiber optic micro accelerometer

    DOE Patents [OSTI]

    Swierkowski, Steve P.

    2005-07-26T23:59:59.000Z

    An accelerometer includes a wafer, a proof mass integrated into the wafer, at least one spring member connected to the proof mass, and an optical fiber. A Fabry-Perot cavity is formed by a partially reflective surface on the proof mass and a partially reflective surface on the end of the optical fiber. The two partially reflective surfaces are used to detect movement of the proof mass through the optical fiber, using an optical detection system.

  3. Parallization of Stellar Atmosphere Codes

    E-Print Network [OSTI]

    P. Hoeflich

    2002-09-19T23:59:59.000Z

    Parallel computing has turned out to be the enabling technology to solve complex physical systems. However, the transition from shared memory, vector computers to massively parallel, distributed memory systems and, recently, to hybrid systems poses new challenges to the scientist. We want to present a cook-book (with a very strong, personal bias) based on our experience with parallization of our existing codes. Some of the general tools and communication libraries are discussed. Our approach includes a mixture of algorithm, domain and physical module based parallization. The advantages, scalability and limitations of each are discussed at some examples. We want show that it becomes easier to write parallel code with increasing complexity of the physical problem making stellar atmosphere codes beyond the classical assumptions very suitable.

  4. Limits to the lunar atmosphere

    SciTech Connect (OSTI)

    Morgan, T.H. (National Aeronautics and Space Administration, Washington, D.C. (USA)); Shemansky, D.E. (Univ. of Arizona, Tucson (USA))

    1991-02-01T23:59:59.000Z

    The presence of sodium and potassium on the Moon implies that other more abundant species should be present. Volatile molecules like H{sub 2}O are significantly more abundant than sodium in any of the proposed external atmospheric sources. Source mechanisms which derive atoms from the surface should favor abundant elements in the regolith. It is therefore puzzling that the Apollo ultraviolet spectrometer experiment set limits on the density of oxygen of N{sub O} < 5 {times} 10{sup 2} cm{sup {minus}3}, and that the Apollo Lunar Atmospheric Composition Experiment data imply N{sub O} < 50 cm{sup {minus}3} above the subsolar point. These limits are surprisingly small relative to the measured value for sodium. A simple consideration of sources and sinks predicts significantly greater densities of oxygen. It is possible but doubtful that the Apollo measurements occur ed during an epoch in which source rates were small. A preferential loss process for oxygen on the darkside of the Moon is considered in which ionization by electron capture in surface collisions leads to escape through acceleration in the local electric field. Cold trapping in permanently shadowed regions as a net sink is considered and discounted, but the episodic nature of cometary insertion may allow formation of ice layers which act as a stablized source of OH. On the basis of an assumed meteoroid impact source, the authors predict a possible emission brightness of {approximately} 50 R in the OH(A {minus} X)(0,0) band above the lunar bright limb. A very uncertain small comet source of H{sub 2}O could raise this value by more than two orders of magnitude.

  5. University of Central Florida College of Optics & Photonics Optics

    E-Print Network [OSTI]

    Van Stryland, Eric

    University of Central Florida College of Optics & Photonics Optics Spring 2010 OSE-6432: Principles of guided wave optics; electro -optics, acousto-optics and optoelectronics. Location: CREOL-A-214 or by Appointment Reference Materials: 1. Class Notes. 2. "Fundamentals of Optical Waveguides", K. Okamoto, Academic

  6. Doctoral Programs Atmospheric, Oceanic & Space Sciences

    E-Print Network [OSTI]

    Eustice, Ryan

    University of Michigan Space Research Building 2455 Hayward Street Ann Arbor, MI 48109-2143 aoss Katherine E. White, Ann Arbor ©The Regents of the University of Michigan Research areas Atmospheric Science Atmospheric Dynamics Climate, Climate Modeling & Climate Change Clouds & Precipitation Paleoclimate, Ice

  7. Human effects on the global atmosphere

    SciTech Connect (OSTI)

    Johnston, H.S.

    1984-01-01T23:59:59.000Z

    This review considers whether human activities can significantly change important functions of the global atmosphere by altering the amount or distribution of certain trace species. It deals with three specific topics: stratopheric ozone, the role of species other than carbon dioxide on the greenhouse effect, and certain recently recognized atmospheric consequences of a large scale nuclear war. 64 references, 10 figures, 2 tables.

  8. ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. (2013)

    E-Print Network [OSTI]

    Lee, Sukyoung

    2013-01-01T23:59:59.000Z

    ATMOSPHERIC SCIENCE LETTERS Atmos. Sci. Let. (2013) Published online in Wiley Online Library Sciences, Seoul National University, Seoul, South Korea *Correspondence to: C. Yoo, Center for Atmosphere). A number of studies have shown that the MJO plays an important role in modulating the extratropical cir

  9. ATOMIC IONIZATION AND OPACITIES IN PULSAR ATMOSPHERES

    E-Print Network [OSTI]

    ATOMIC IONIZATION AND OPACITIES IN PULSAR ATMOSPHERES Hydrogen Atmospheres J. VENTURA Physics.g. Pavlov et al., 1995; Zavlin et al., 1995, 1996; #12; 2 J. VENTURA ET AL. Rajagopal and Romani, 1996 the past three years. As is well known (Canuto and Ventura, 1977; Ruder et al., 1994), the external strong

  10. Atmospheric neutrino flux calculation using the NRLMSISE00 atmospheric model

    E-Print Network [OSTI]

    Honda, M; Kajita, T; Kasahara, K; Midorikawa, S

    2015-01-01T23:59:59.000Z

    In this paper, we extend the calculation of the atmospheric neutrino flux~\\cite{hkkm2004,hkkms2006,hkkm2011} to the sites in polar and tropical regions. In our earliest full 3D-calculation~\\cite{hkkm2004}, we used DPMJET-III~\\cite{dpm} for the hadronic interaction model above 5~GeV, and NUCRIN~\\cite{nucrin} below 5~GeV. We modified DPMJET-III as in Ref.~\\cite{hkkms2006} to reproduce the experimental muon spectra better, mainly using the data observed by BESS group~\\cite{BESSTeVpHemu}. In a recent work~\\cite{hkkm2011}, we introduced JAM interaction model for the low energy hadronic interactions. JAM is a nuclear interaction model developed with PHITS (Particle and Heavy-Ion Transport code System)~\\cite{phits}. In Ref.~\\cite{hkkm2011}, we could reproduce the observed muon flux at the low energies at balloon altitude with DPMJET-III above 32 GeV and JAM below that better than the combination of DPMJET-III above 5~GeV and NUCRIN below that. Besides the interaction model, we have also improved the calculation sche...

  11. Atmospheric sampling glow discharge ionization source

    DOE Patents [OSTI]

    McLuckey, S.A.; Glish, G.L.

    1989-07-18T23:59:59.000Z

    An atmospheric sampling glow discharge ionization source that can be used in combination with an analytical instrument which operates at high vacuum, such as a mass spectrometer. The atmospheric sampling glow discharge ionization source comprises a chamber with at least one pair of electrodes disposed therein, an inlet for a gaseous sample to be analyzed and an outlet communicating with an analyzer which operates at subatmospheric pressure. The ionization chamber is maintained at a pressure below atmospheric pressure, and a voltage difference is applied across the electrodes to induce a glow discharge between the electrodes, so that molecules passing through the inlet are ionized by the glow discharge and directed into the analyzer. The ionization source accepts the sample under atmospheric pressure conditions and processes it directly into the high vacuum instrument, bridging the pressure gap and drawing off unwanted atmospheric gases. The invention also includes a method for analyzing a gaseous sample using the glow discharge ionization source described above. 3 figs.

  12. Calibration of LSST Instrumental and Atmospheric Photometric Passbands

    SciTech Connect (OSTI)

    Burke, David L.; /SLAC; Axelrod, T.; /Arizona U., Astron. Dept. - Steward Observ.; Barrau, Aurelien; Baumont, Sylvain; /LPSC, Grenoble; Blondin, Stephane; /Marseille, CPPM; Claver, Chuck; /NOAO, Tucson; Gorecki, Alexia; /LPSC, Grenoble; Ivezic, Zeljko; Jones, Lynne; /Washington U., Seattle, Astron. Dept.; Krabbendam, Victor; Liang, Ming; Saha, Abhijit; /NOAO, Tucson; Smith, Allyn; /Austin Peay State U.; Smith, R.Chris; /Cerro-Tololo InterAmerican Obs.; Stubbs, Christopher W.; /Harvard-Smithsonian Ctr. Astrophys.

    2011-07-06T23:59:59.000Z

    The Large Synoptic Survey Telescope (LSST) will continuously image the entire sky visible from Cerro Pachon in northern Chile every 3-4 nights throughout the year. The LSST will provide data for a broad range of science investigations that require better than 1% photometric precision across the sky (repeatability and uniformity) and a similar accuracy of measured broadband color. The fast and persistent cadence of the LSST survey will significantly improve the temporal sampling rate with which celestial events and motions are tracked. To achieve these goals, and to optimally utilize the observing calendar, it will be necessary to obtain excellent photometric calibration of data taken over a wide range of observing conditions - even those not normally considered 'photometric'. To achieve this it will be necessary to routinely and accurately measure the full optical passband that includes the atmosphere as well as the instrumental telescope and camera system. The LSST mountain facility will include a new monochromatic dome illumination projector system to measure the detailed wavelength dependence of the instrumental passband for each channel in the system. The facility will also include an auxiliary spectroscopic telescope dedicated to measurement of atmospheric transparency at all locations in the sky during LSST observing. In this paper, we describe these systems and present laboratory and observational data that illustrate their performance.

  13. Atmospheric-pressure plasma decontamination/sterilization chamber

    DOE Patents [OSTI]

    Herrmann, Hans W. (Los Alamos, NM); Selwyn, Gary S. (Los Alamos, NM)

    2001-01-01T23:59:59.000Z

    An atmospheric-pressure plasma decontamination/sterilization chamber is described. The apparatus is useful for decontaminating sensitive equipment and materials, such as electronics, optics and national treasures, which have been contaminated with chemical and/or biological warfare agents, such as anthrax, mustard blistering agent, VX nerve gas, and the like. There is currently no acceptable procedure for decontaminating such equipment. The apparatus may also be used for sterilization in the medical and food industries. Items to be decontaminated or sterilized are supported inside the chamber. Reactive gases containing atomic and metastable oxygen species are generated by an atmospheric-pressure plasma discharge in a He/O.sub.2 mixture and directed into the region of these items resulting in chemical reaction between the reactive species and organic substances. This reaction typically kills and/or neutralizes the contamination without damaging most equipment and materials. The plasma gases are recirculated through a closed-loop system to minimize the loss of helium and the possibility of escape of aerosolized harmful substances.

  14. Implications of atmospheric test fallout data for nuclear winter

    SciTech Connect (OSTI)

    Baker, G.H. III

    1987-01-01T23:59:59.000Z

    Atmospheric-test fallout data were used to determine admissable-dust particle-size distributions for nuclear-winter studies. The research was originally motivated by extreme differences noted in the magnitude and longevity of dust effects predicted by particle-size distributions routinely used in fallout predictions versus those used for nuclear-winter studies. Three different sets of historical data were analyzed: (1) stratospheric burden of strontium-90 and tungsten-185, 1954-1967 (92 contributing events); (2) continental US strontium-90 fallout through 1958 (75 contributing events); (3) local fallout from selected Nevada tests (16 events). The contribution of dust to possible long-term climate effects following a nuclear exchange depends strongly on the particle-size distribution. The distribution affects both the atmospheric residence time and optical depth. One-dimensional models of stratospheric/tropospheric fallout removal were developed and used to identify optimum particle distributions. Results indicate that particle distributions that properly predict bulk stratospheric activity transfer tend to be somewhat smaller than number size distributions used in initial nuclear winter studies. In addition, both /sup 90/Sr and /sup 185/W fallout behavior is better predicted by the log normal distribution function than the prevalent power-law hybrid function.

  15. Omnidirectional fiber optic tiltmeter

    DOE Patents [OSTI]

    Benjamin, B.C.; Miller, H.M.

    1983-06-30T23:59:59.000Z

    A tiltmeter is provided which is useful in detecting very small movements such as earth tides. The device comprises a single optical fiber, and an associated weight affixed thereto, suspended from a support to form a pendulum. A light source, e.g., a light emitting diode, mounted on the support transmits light through the optical fiber to a group of further optical fibers located adjacent to but spaced from the free end of the single optical fiber so that displacement of the single optical fiber with respect to the group will result in a change in the amount of light received by the individual optical fibers of the group. Photodetectors individually connectd to the fibers produce corresponding electrical outputs which are differentially compared and processed to produce a resultant continuous analog output representative of the amount and direction of displacement of the single optical fiber.

  16. Fiber optic vibration sensor

    DOE Patents [OSTI]

    Dooley, Joseph B. (Harriman, TN); Muhs, Jeffrey D. (Lenoir City, TN); Tobin, Kenneth W. (Harriman, TN)

    1995-01-01T23:59:59.000Z

    A fiber optic vibration sensor utilizes two single mode optical fibers supported by a housing with one optical fiber fixedly secured to the housing and providing a reference signal and the other optical fiber having a free span length subject to vibrational displacement thereof with respect to the housing and the first optical fiber for providing a signal indicative of a measurement of any perturbation of the sensor. Damping or tailoring of the sensor to be responsive to selected levels of perturbation is provided by altering the diameter of optical fibers or by immersing at least a portion of the free span length of the vibration sensing optical fiber into a liquid of a selected viscosity.

  17. Fiber optic vibration sensor

    DOE Patents [OSTI]

    Dooley, J.B.; Muhs, J.D.; Tobin, K.W.

    1995-01-10T23:59:59.000Z

    A fiber optic vibration sensor utilizes two single mode optical fibers supported by a housing with one optical fiber fixedly secured to the housing and providing a reference signal and the other optical fiber having a free span length subject to vibrational displacement thereof with respect to the housing and the first optical fiber for providing a signal indicative of a measurement of any perturbation of the sensor. Damping or tailoring of the sensor to be responsive to selected levels of perturbation is provided by altering the diameter of optical fibers or by immersing at least a portion of the free span length of the vibration sensing optical fiber into a liquid of a selected viscosity. 2 figures.

  18. Modular Optical PDV System

    SciTech Connect (OSTI)

    Araceli Rutkowski, David Esquibel

    2008-12-11T23:59:59.000Z

    A modular optical photon Doppler velocimetry (PDV) detector system has been developed by using readily available optical components with a 20-GHz Miteq optical detector into eight channels of single-wide modules integrated into a 3U rack unit (1U = 1.75 inches) with a common power supply. Optical fibers were precisely trimmed, welded, and timed within each unit. This system has been used to collect dynamic velocity data on various physics experiments. An optical power meter displays the laser input power to the module and optical power at the detector. An adjustable micro-electromechanical system (MEMS) optical attenuator is used to adjust the amount of unshifted light entering the detector. Front panel LEDs show the presence of power to the module. A fully loaded chassis with eight channels consumes 45 watts of power. Each chassis requires 1U spacing above and below for heat management. Modules can be easily replaced.

  19. Evolution of glass properties during a substitution of S by Se in Ge28Sb12S60-xSex glass Guillaume Guery1,2

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Evolution of glass properties during a substitution of S by Se in Ge28Sb12S60-xSex glass network, Université de Bordeaux I, Avenue du Dr Schweitzer, 33608 Pessac Cedex, France. Keywords: Chalcogenide glass; Raman spectroscopy; X-ray photoelectron spectroscopy; Glass properties Author whom correspondence should

  20. Confirmatory Survey Report for Area B1S/B2S at the Chevron Mining Washington Remediation Project, Washington, PA

    SciTech Connect (OSTI)

    W. C. Adams

    2007-11-20T23:59:59.000Z

    During the period of October 2 and 3, 2007, the Oak Ridge Institute for Science and Education (ORISE) performed confirmatory radiological survey activities which included gamma surface scans within Area B1S/B2S and the collection of soil samples from these areas.

  1. Jimmy Krozel is with Metron Aviation, Inc., Herndon, VA. Changkil Lee and Joseph S.B. Mitchell are with Stony Brook University, Stony Brook, NY.

    E-Print Network [OSTI]

    Mitchell, Joseph S.B.

    [Federal Aviation Administration, 2003]) lists weather as the leading cause (65% to 75%) of delays greater inclement weather, throughput is adversely affected. The Aviation Capacity Enhancement Plan (FAA ACE Plan. Jimmy Krozel is with Metron Aviation, Inc., Herndon, VA. Changkil Lee and Joseph S.B. Mitchell

  2. Zintl Phases as Thermoelectric Materials: Tuned Transport Properties of the Compounds CaxYb1xZn2Sb2**

    E-Print Network [OSTI]

    Zintl Phases as Thermoelectric Materials: Tuned Transport Properties of the Compounds CaxYb1±xZn2Sb. Introduction Because of their ability to convert waste heat into electricity, thermoelectric materials have in efficiency, thermoelectric materials could pro- vide a substantial amount of electrical power from automotive

  3. Thermoelectric Properties of n-type Polycrystalline BixSb2-xTe3 Alloys N. Gerovac, G. J. Snyder, and T. Caillat

    E-Print Network [OSTI]

    Thermoelectric Properties of n-type Polycrystalline BixSb2-xTe3 Alloys N. Gerovac, G. J. Snyder their atomic composition. The thermoelectric properties were measured at room temperature in both directions. The thermoelectric figure-of-merit, ZT, was calculated from these properties. The best ZT was ~.5, given by annealed

  4. Compositionally-graded InGaAsInGaP alloys and GaAsSb alloys for metamorphic InP on GaAs

    E-Print Network [OSTI]

    Compositionally-graded InGaAs­InGaP alloys and GaAsSb alloys for metamorphic InP on GaAs Li Yang a of tandem graded layers of InGaAs and InGaP with compositional grading of the In concentration. This tandem

  5. High-Temperature Thermoelectric Properties of the Solid–Solution Zintl Phase Eu11Cd6Sb12–xAsx (x < 3)

    SciTech Connect (OSTI)

    Kazem, Nasrin; Xie, Weiwei; Ohno, Saneyuki; Zevalkink, Alexandra; Miller, Gordon J; Snyder, G Jeffrey; Kauzlarich, Susan M

    2014-02-11T23:59:59.000Z

    Zintl phases are compounds that have shown promise for thermoelectric applications. The title solid–solution Zintl compounds were prepared from the elements as single crystals using a tin flux for compositions x = 0, 1, 2, and 3. Eu11Cd6Sb12–xAsx (x < 3) crystallize isostructurally in the centrosymmetric monoclinic space group C2/m (no. 12, Z = 2) as the Sr11Cd6Sb12 structure type (Pearson symbol mC58). Efforts to make the As compositions for x exceeding ?3 resulted in structures other than the Sr11Cd6Sb12 structure type. Single-crystal X-ray diffraction indicates that As does not randomly substitute for Sb in the structure but is site specific for each composition. The amount of As determined by structural refinement was verified by electron microprobe analysis. Electronic structures and energies calculated for various model structures of Eu11Cd6Sb10As2 (x = 2) indicated that the preferred As substitution pattern involves a mixture of three of the six pnicogen sites in the asymmetric unit. In addition, As substitution at the Pn4 site opens an energy gap at the Fermi level, whereas substitution at the other five pnicogen sites remains semimetallic with a pseudo gap. Thermoelectric properties of these compounds were measured on hot-pressed, fully densified pellets. Samples show exceptionally low lattice thermal conductivities from room temperature to 775 K: 0.78–0.49 W/mK for x = 0; 0.72–0.53 W/mK for x = 1; and 0.70–0.56 W/mK for x = 2. Eu11Cd6Sb12 shows a high p-type Seebeck coefficient (from +118 to 153 ? V/K) but also high electrical resistivity (6.8 to 12.8 m?·cm). The value of zT reaches 0.23 at 774 K. The properties of Eu11Cd6Sb12–xAsx are interpreted in discussion with the As site substitution.

  6. Topological insulators in Bi2Se3, Bi2Te3 and Sb2Te3 with a single Dirac cone on the surface

    SciTech Connect (OSTI)

    Zhang, Haijun; /Beijing, Inst. Phys.; Liu, Chao-Xing; /Tsinghua U., Beijing; Qi, Xiao-Liang; /Stanford U., Phys. Dept.; Dai, Xi; Fang, Zhong; /Beijing, Inst. Phys.; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.

    2010-02-24T23:59:59.000Z

    Topological insulators are new states of quantum matter in which surface states residing in the bulk insulating gap of such systems are protected by time-reversal symmetry. The study of such states was originally inspired by the robustness to scattering of conducting edge states in quantum Hall systems. Recently, such analogies have resulted in the discovery of topologically protected states in two-dimensional and three-dimensional band insulators with large spin-orbit coupling. So far, the only known three-dimensional topological insulator is Bi{sub x}Sb{sub 1-x}, which is an alloy with complex surface states. Here, we present the results of first-principles electronic structure calculations of the layered, stoichiometric crystals Sb{sub 2}Te{sub 3}, Sb{sub 2}Se{sub 3}, Bi{sub 2}Te{sub 3} and Bi{sub 2}Se{sub 3}. Our calculations predict that Sb{sub 2}Te{sub 3}, Bi{sub 2}Te{sub 3} and Bi{sub 2}Se{sub 3} are topological insulators, whereas Sb{sub 2}Se{sub 3} is not. These topological insulators have robust and simple surface states consisting of a single Dirac cone at the point. In addition, we predict that Bi{sub 2}Se{sub 3} has a topologically non-trivial energy gap of 0.3 eV, which is larger than the energy scale of room temperature. We further present a simple and unified continuum model that captures the salient topological features of this class of materials.

  7. Hyperspectral Aerosol Optical Depths from TCAP Flights

    SciTech Connect (OSTI)

    Shinozuka, Yohei; Johnson, Roy R.; Flynn, Connor J.; Russell, P. B.; Schmid, Beat; Redemann, Jens; Dunagan, Stephen; Kluzek, Celine D.; Hubbe, John M.; Segal-Rosenheimer, Michal; Livingston, J. M.; Eck, T.; Wagener, Richard; Gregory, L.; Chand, Duli; Berg, Larry K.; Rogers, Ray; Ferrare, R. A.; Hair, John; Hostetler, Chris A.; Burton, S. P.

    2013-11-13T23:59:59.000Z

    4STAR (Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research), the world’s first hyperspectral airborne tracking sunphotometer, acquired aerosol optical depths (AOD) at 1 Hz during all July 2012 flights of the Two Column Aerosol Project (TCAP). Root-mean square differences from AERONET ground-based observations were 0.01 at wavelengths between 500-1020 nm, 0.02 at 380 and 1640 nm and 0.03 at 440 nm in four clear-sky fly-over events, and similar in ground side-by-side comparisons. Changes in the above-aircraft AOD across 3-km-deep spirals were typically consistent with integrals of coincident in situ (on DOE Gulfstream 1 with 4STAR) and lidar (on NASA B200) extinction measurements within 0.01, 0.03, 0.01, 0.02, 0.02, 0.02 at 355, 450, 532, 550, 700, 1064 nm, respectively, despite atmospheric variations and combined measurement uncertainties. Finer vertical differentials of the 4STAR measurements matched the in situ ambient extinction profile within 14% for one homogeneous column. For the AOD observed between 350-1660 nm, excluding strong water vapor and oxygen absorption bands, estimated uncertainties were ~0.01 and dominated by (then) unpredictable throughput changes, up to +/-0.8%, of the fiber optic rotary joint. The favorable intercomparisons herald 4STAR’s spatially-resolved high-frequency hyperspectral products as a reliable tool for climate studies and satellite validation.

  8. The Upper Atmosphere of HD17156b

    E-Print Network [OSTI]

    T. T. Koskinen; A. D. Aylward; S. Miller

    2008-11-28T23:59:59.000Z

    HD17156b is a newly-found transiting extrasolar giant planet (EGP) that orbits its G-type host star in a highly eccentric orbit (e~0.67) with an orbital semi-major axis of 0.16 AU. Its period, 21.2 Earth days, is the longest among the known transiting planets. The atmosphere of the planet undergoes a 27-fold variation in stellar irradiation during each orbit, making it an interesting subject for atmospheric modelling. We have used a three-dimensional model of the upper atmosphere and ionosphere for extrasolar gas giants in order to simulate the progress of HD17156b along its eccentric orbit. Here we present the results of these simulations and discuss the stability, circulation, and composition in its upper atmosphere. Contrary to the well-known transiting planet HD209458b, we find that the atmosphere of HD17156b is unlikely to escape hydrodynamically at any point along the orbit, even if the upper atmosphere is almost entirely composed of atomic hydrogen and H+, and infrared cooling by H3+ ions is negligible. The nature of the upper atmosphere is sensitive to to the composition of the thermosphere, and in particular to the mixing ratio of H2, as the availability of H2 regulates radiative cooling. In light of different simulations we make specific predictions about the thermosphere-ionosphere system of HD17156b that can potentially be verified by observations.

  9. Mass spectrometric approaches for chemical characterisation of atmospheric aerosols: critical

    E-Print Network [OSTI]

    Nizkorodov, Sergey

    Mass spectrometric approaches for chemical characterisation of atmospheric aerosols: critical. Atmospheric aerosols have profound effects on the environment through several physicochemical processes on the respiratory and cardiovascular systems. Understanding aerosol atmospheric chemistry and its environmental

  10. Atomic intermixing and interface roughness in short-period InAs/GaSb superlattices for infrared photodetectors

    SciTech Connect (OSTI)

    Ashuach, Y.; Lakin, E.; Kaufmann, Y. [Department of Materials Science and Engineering, Technion—Israel Institute of Technology, Haifa 32000 (Israel); Saguy, C. [Solid State Institute, Technion—Israel Institute of Technology, Haifa 32000 (Israel); Zolotoyabko, E., E-mail: zloto@tx.technion.ac.il [Department of Materials Science and Engineering, Technion—Israel Institute of Technology, Haifa 32000 (Israel); Solid State Institute, Technion—Israel Institute of Technology, Haifa 32000 (Israel)

    2014-09-28T23:59:59.000Z

    A set of advanced characterization methods, including high-resolution X-ray diffraction (measurements and simulations), cross-sectional scanning tunneling microscopy, and high-angle annular dark-field scanning transmission electron microscopy is applied to quantify the interface roughness and atomic intermixing (in both cation and anion sub-lattices) in short period (6–7?nm) InAs/GaSb superlattices intended for mid-wavelength (M) and long-wavelength (L) infrared detectors. The undesired atomic intermixing and interface roughness in the L-samples were found to be considerably lower than in the M-samples. In all specimens, anion intermixing is much higher than that in the cation sub-lattice. Possible origins of these findings are discussed.

  11. Proposal for a second-generation, lattice matched, multiple junction Ga{sub 2}AsSb TPV converter

    SciTech Connect (OSTI)

    Horner, G.S. [Keithley Instruments, Solon Ohio (United States); Coutts, T.J.; Wanlass, M.W. [National Renewable Energy Laboratory, Golden Colorado (United States)

    1995-01-05T23:59:59.000Z

    First order device modeling is used to show that spontaneously ordered Ga{sub 2}AsSb may prove useful in the newly-active field of thermophotovoltaic power generation. Optimal band gaps for single-, double- and triple-junction III-V devices are presented for a range of blackbody emitter temperatures (1000--2000 K), and it is shown that monolithic, current-matched devices may be constructed that are lattice-matched throughout the stack to an underlying InP substrate. Device efficiency, short-circuit current, fill factor, and open-circuit voltage calculations are presented. The power generation capabilities are expected to be substantial due to the proximity of the devices to the thermal radiators. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  12. Characteristics of GaAsSb single quantum well lasers emitting near 1.3 {micro}m

    SciTech Connect (OSTI)

    SPAHN,OLGA B.; KLEM,JOHN F.

    2000-02-17T23:59:59.000Z

    The authors report data on GaAsSb single quantum well lasers grown on GaAs substrates. Room temperature pulsed emission at 1.275 {micro}m in a 1,250 {micro}m-long device has been observed. Minimum threshold current densities of 535 A/cm{sup 2} were measured in 2000 {micro}m long lasers. The authors also measured internal losses of 2--5 cm{sup {minus}1}, internal quantum efficiencies of 30-38% and characteristic temperature T{sub 0} of 67--77 C. From these parameters a gain constant G{sub 0} of 1,660 cm{sup {minus}1} and a transparency current density J{sub tr} of 134 A/cm{sup 2} were calculated. The results indicate the potential for fabricating 1.3 {micro}m VCSELs from these materials.

  13. Measurement and modeling of infrared nonlinear absorption coefficients and laser-induced damage thresholds in Ge and GaSb

    SciTech Connect (OSTI)

    Wagner, T. J.; Bohn, M. J.; Coutu, R. A. Jr. [Air Force Institute of Technology, Wright Patterson Air Force Base, Ohio 45433 (United States); Gonzalez, L. P.; Murray, J. M.; Guha, S. [Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright Patterson Air Force Base, Ohio 45433 (United States); Schepler, K. L. [Air Force Research Laboratory, Sensors Directorate, Wright Patterson Air Force Base, Ohio 45433 (United States)

    2010-10-15T23:59:59.000Z

    Using a simultaneous fitting technique to extract nonlinear absorption coefficients from data at two pulse widths, we measure two-photon and free-carrier absorption coefficients for Ge and GaSb at 2.05 and 2.5 {mu}m for the first time, to our knowledge. Results agreed well with published theory. Single-shot damage thresholds were also measured at 2.5 {mu}m and agreed well with modeled thresholds using experimentally determined parameters including nonlinear absorption coefficients and temperature dependent linear absorption. The damage threshold for a single-layer Al{sub 2}O{sub 3} anti-reflective coating on Ge was 55% or 35% lower than the uncoated threshold for picosecond or nanosecond pulses, respectively.

  14. Atmospheric science encompasses meteorology and climatology, as well as fields such as atmospheric chemistry and remote sensing.Atmospheric

    E-Print Network [OSTI]

    Oceanography and Meteorology Building.The Doppler weather radar on the roof of the building is a campus Mobile Atmospheric Research and Teaching Radar (SMART-R).This radar is used in national and international

  15. Microphysical and Dynamical Influences on Cirrus Cloud Optical Depth Distributions

    SciTech Connect (OSTI)

    Kay, J.; Baker, M.; Hegg, D.

    2005-03-18T23:59:59.000Z

    Cirrus cloud inhomogeneity occurs at scales greater than the cirrus radiative smoothing scale ({approx}100 m), but less than typical global climate model (GCM) resolutions ({approx}300 km). Therefore, calculating cirrus radiative impacts in GCMs requires an optical depth distribution parameterization. Radiative transfer calculations are sensitive to optical depth distribution assumptions (Fu et al. 2000; Carlin et al. 2002). Using raman lidar observations, we quantify cirrus timescales and optical depth distributions at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site in Lamont, OK (USA). We demonstrate the sensitivity of outgoing longwave radiation (OLR) calculations to assumed optical depth distributions and to the temporal resolution of optical depth measurements. Recent work has highlighted the importance of dynamics and nucleation for cirrus evolution (Haag and Karcher 2004; Karcher and Strom 2003). We need to understand the main controls on cirrus optical depth distributions to incorporate cirrus variability into model radiative transfer calculations. With an explicit ice microphysics parcel model, we aim to understand the influence of ice nucleation mechanism and imposed dynamics on cirrus optical depth distributions.

  16. Compound semiconductor optical waveguide switch

    DOE Patents [OSTI]

    Spahn, Olga B.; Sullivan, Charles T.; Garcia, Ernest J.

    2003-06-10T23:59:59.000Z

    An optical waveguide switch is disclosed which is formed from III-V compound semiconductors and which has a moveable optical waveguide with a cantilevered portion that can be bent laterally by an integral electrostatic actuator to route an optical signal (i.e. light) between the moveable optical waveguide and one of a plurality of fixed optical waveguides. A plurality of optical waveguide switches can be formed on a common substrate and interconnected to form an optical switching network.

  17. Collisionless Shocks and TeV Neutrinos before Supernova Shock Breakout from an Optically Thick Wind

    E-Print Network [OSTI]

    Giacinti, G

    2015-01-01T23:59:59.000Z

    During a supernova explosion, a radiation-dominated shock (RDS) travels through its progenitor. A collisionless shock (CS) is usually assumed to replace it during shock breakout (SB). We demonstrate here that for some realistic progenitors enshrouded in optically thick winds, such as possibly SN 2008D, a CS forms deep inside the wind, soon after the RDS leaves the core, and therefore significantly before SB. The RDS does not survive the transition from the core to the thick wind when the wind close to the core is not sufficiently dense to compensate for the $r^{-2}$ dilution of photons due to shock curvature. This typically happens when the shock velocity is $\\lesssim 0.1 {\\rm c} \\, (\\frac{u_{\\rm w}}{10\\,{\\rm km/s}}) (\\frac{\\dot{M}}{5 \\cdot 10^{-4} \\, {\\rm M}_\\odot {\\rm /yr}})^{-1} (\\frac{r_\\ast}{10^{13}\\,{\\rm cm}})$, where $u_{\\rm w}$, $\\dot{M}$ and $r_\\ast$ are respectively the wind velocity, mass-loss rate and radius of the progenitor star. The radiative CS results in a hard spectrum of the photon flash at...

  18. Oil and gas exploration system and method for detecting trace amounts of hydrocarbon gases in the atmosphere

    DOE Patents [OSTI]

    Wamsley, Paula R. (Littleton, CO); Weimer, Carl S. (Littleton, CO); Nelson, Loren D. (Evergreen, CO); O'Brien, Martin J. (Pine, CO)

    2003-01-01T23:59:59.000Z

    An oil and gas exploration system and method for land and airborne operations, the system and method used for locating subsurface hydrocarbon deposits based upon a remote detection of trace amounts of gases in the atmosphere. The detection of one or more target gases in the atmosphere is used to indicate a possible subsurface oil and gas deposit. By mapping a plurality of gas targets over a selected survey area, the survey area can be analyzed for measurable concentration anomalies. The anomalies are interpreted along with other exploration data to evaluate the value of an underground deposit. The system includes a differential absorption lidar (DIAL) system with a spectroscopic grade laser light and a light detector. The laser light is continuously tunable in a mid-infrared range, 2 to 5 micrometers, for choosing appropriate wavelengths to measure different gases and avoid absorption bands of interference gases. The laser light has sufficient optical energy to measure atmospheric concentrations of a gas over a path as long as a mile and greater. The detection of the gas is based on optical absorption measurements at specific wavelengths in the open atmosphere. Light that is detected using the light detector contains an absorption signature acquired as the light travels through the atmosphere from the laser source and back to the light detector. The absorption signature of each gas is processed and then analyzed to determine if a potential anomaly exists.

  19. Multichannel optical sensing device

    DOE Patents [OSTI]

    Selkowitz, Stephen E. (Piedmont, CA)

    1990-01-01T23:59:59.000Z

    A multichannel optical sensing device is disclosed, for measuring the outr sky luminance or illuminance or the luminance or illuminance distribution in a room, comprising a plurality of light receptors, an optical shutter matrix including a plurality of liquid crystal optical shutter elements operable by electrical control signals between light transmitting and light stopping conditions, fiber optic elements connected between the receptors and the shutter elements, a microprocessor based programmable control unit for selectively supplying control signals to the optical shutter elements in a programmable sequence, a photodetector including an optical integrating spherical chamber having an input port for receiving the light from the shutter matrix and at least one detector element in the spherical chamber for producing output signals corresponding to the light, and output units for utilizing the output signals including a storage unit having a control connection to the microprocessor based programmable control unit for storing the output signals under the sequence control of the programmable control unit.

  20. Multichannel optical sensing device

    DOE Patents [OSTI]

    Selkowitz, S.E.

    1985-08-16T23:59:59.000Z

    A multichannel optical sensing device is disclosed, for measuring the outdoor sky luminance or illuminance or the luminance or illuminance distribution in a room, comprising a plurality of light receptors, an optical shutter matrix including a plurality of liquid crystal optical shutter elements operable by electrical control signals between light transmitting and light stopping conditions, fiber optical elements connected between the receptors and the shutter elements, a microprocessor based programmable control unit for selectively supplying control signals to the optical shutter elements in a programmable sequence, a photodetector including an optical integrating spherical chamber having an input port for receiving the light from the shutter matrix and at least one detector element in the spherical chamber for producing output signals corresponding to the light, and output units for utilizing the output signals including a storage unit having a control connection to the microprocessor based programmable control unit for storing the output signals under the sequence control of the programmable control unit.

  1. Transpiration purged optical probe

    DOE Patents [OSTI]

    2004-01-06T23:59:59.000Z

    An optical apparatus for clearly viewing the interior of a containment vessel by applying a transpiration fluid to a volume directly in front of the external surface of the optical element of the optical apparatus. The fluid is provided by an external source and transported by means of an annular tube to a capped end region where the inner tube is perforated. The perforation allows the fluid to stream axially towards the center of the inner tube and then axially away from an optical element which is positioned in the inner tube just prior to the porous sleeve. This arrangement draws any contaminants away from the optical element keeping it free of contaminants. In one of several embodiments, the optical element can be a lens, a viewing port or a laser, and the external source can provide a transpiration fluid having either steady properties or time varying properties.

  2. Entanglement in Classical Optics

    E-Print Network [OSTI]

    Partha Ghose; Anirban Mukherjee

    2013-09-12T23:59:59.000Z

    The emerging field of entanglement or nonseparability in classical optics is reviewed, and its similarities with and differences from quantum entanglement clearly pointed out through a recapitulation of Hilbert spaces in general, the special restrictions on Hilbert spaces imposed in quantum mechanics and the role of Hilbert spaces in classical polarization optics. The production of Bell-like states in classical polarization optics is discussed, and new theorems are proved to discriminate between separable and nonseparable states in classical wave optics where no discreteness is involved. The influence of the Pancharatnam phase on a classical Bell-like state is deived. Finally, to what extent classical polarization optics can be used to simulate quantum information processing tasks is also discussed. This should be of great practical importance because coherence and entanglement are robust in classical optics but not in quantum systems.

  3. Pulsed atmospheric fluidized bed combustion

    SciTech Connect (OSTI)

    Not Available

    1989-11-01T23:59:59.000Z

    In order to verify the technical feasibility of the MTCI Pulsed Atmospheric Fluidized Bed Combustor technology, a laboratory-scale system was designed, built and tested. Important aspects of the operational and performance parameters of the system were established experimentally. A considerable amount of the effort was invested in the initial task of constructing an AFBC that would represent a reasonable baseline against which the performance of the PAFBC could be compared. A summary comparison of the performance and emissions data from the MTCI 2 ft {times} 2 ft facility (AFBC and PAFBC modes) with those from conventional BFBC (taller freeboard and recycle operation) and circulating fluidized bed combustion (CFBC) units is given in Table ES-1. The comparison is for typical high-volatile bituminous coals and sorbents of average reactivity. The values indicated for BFBC and CFBC were based on published information. The AFBC unit that was designed to act as a baseline for the comparison was indeed representative of the larger units even at the smaller scale for which it was designed. The PAFBC mode exhibited superior performance in relation to the AFBC mode. The higher combustion efficiency translates into reduced coal consumption and lower system operating cost; the improvement in sulfur capture implies less sorbent requirement and waste generation and in turn lower operating cost; lower NO{sub x} and CO emissions mean ease of site permitting; and greater steam-generation rate translates into less heat exchange surface area and reduced capital cost. Also, the PAFBC performance generally surpasses those of conventional BFBC, is comparable to CFBC in combustion and NO{sub x} emissions, and is better than CFBC in sulfur capture and CO emissions even at the scaled-down size used for the experimental feasibility tests.

  4. Content Protection for Optical Media Content Protection for Optical Media

    E-Print Network [OSTI]

    Amir, Yair

    Content Protection for Optical Media Content Protection for Optical Media A Comparison of Self-Protecting Digital Content and AACS Independent Security Evaluators www.securityevaluators.com May 3, 2005 Copyright for Optical Media 2 #12;Content Protection for Optical Media Content Protection for Optical Media 3 Executive

  5. atmospheric pressure ionization: Topics by E-print Network

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

    for Atmospheric Pressure, in Vivo, and Imaging Mass. For example, atmospheric pressure infrared MALDI (AP IR-MALDI), capable of producing ions from small ionization (DESI),5...

  6. atmospheric carbon emissions: Topics by E-print Network

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

    oxide (N2O) 13 Paris-Sud XI, Universit de 13 Atmospheric Lifetime of Fossil Fuel Carbon Dioxide Geosciences Websites Summary: Atmospheric Lifetime of Fossil Fuel Carbon...

  7. atmospheric oxygenation recorded: Topics by E-print Network

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

    cores may contain high quality records of atmospheric deposition. The qualitative Short, Daniel 3 Bistability of atmospheric oxygen and the Great Oxidation Geosciences Websites...

  8. atmospheric ion measurements: Topics by E-print Network

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

    the Atmospheric CERN Preprints Summary: We report the first observation in a high energy neutrino telescope of cascades induced by atmospheric electron neutrinos and by...

  9. Comparative Analysis of Urban Atmospheric Aerosol by Particle...

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

    Analysis of Urban Atmospheric Aerosol by Particle-Induced X-ray Emission (PIXE), Proton Elastic Scattering Analysis Comparative Analysis of Urban Atmospheric Aerosol by...

  10. Atmospheric Solids Analysis Probe Mass Spectrometry: A New Approach...

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

    Atmospheric Solids Analysis Probe Mass Spectrometry: A New Approach for Airborne Particle Analysis. Atmospheric Solids Analysis Probe Mass Spectrometry: A New Approach for Airborne...

  11. A Volcanologist'S Review Of Atmospheric Hazards Of Volcanic Activity...

    Open Energy Info (EERE)

    atmospheric hazards caused by explosive volcanic activity. The hazard posed by fine silicate ash with long residence time in the atmosphere is probably much less serious than...

  12. Diesel and Gasoline Engine Emissions: Characterization of Atmosphere...

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

    Characterization of Atmosphere Composition and Health Responses to Inhaled Emissions Diesel and Gasoline Engine Emissions: Characterization of Atmosphere Composition and Health...

  13. Fehner and Gosling, Atmospheric Nuclear Weapons Testing, 1951...

    Energy Savers [EERE]

    Atmospheric Nuclear Weapons Testing, 1951-1963. Battlefield of the Cold War: The Nevada Test Site, Volume I Fehner and Gosling, Atmospheric Nuclear Weapons Testing, 1951-1963....

  14. atmospheric global electric: Topics by E-print Network

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

    global atmospheric iron cycle, and combustion this paper. Key Words aerosol deposition, climate change, deserts Abstract Atmospheric inputs of iron sources of iron are...

  15. atmospheric dispersion coefficient: Topics by E-print Network

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

    the earth surface. In general, the atmospheric motion is driven by the intense solar energy arriving at the equator 3 A GIS-based atmospheric dispersion model Computer...

  16. atmospheric dispersion calculations: Topics by E-print Network

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

    the earth surface. In general, the atmospheric motion is driven by the intense solar energy arriving at the equator 4 A GIS-based atmospheric dispersion model Computer...

  17. atmospheric dispersion experiment: Topics by E-print Network

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

    the earth surface. In general, the atmospheric motion is driven by the intense solar energy arriving at the equator 2 A GIS-based atmospheric dispersion model Computer...

  18. atmospheric climate model: Topics by E-print Network

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

    Curry & Webster Atmospheric Thermodynamics Ch1 Composition Ch2 Laws Ch3 Transfers Ch12 Energy Russell, Lynn 10 Climate Sciences: Atmospheric Thermodynamics Environmental...

  19. atmosphere box model: Topics by E-print Network

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

    GloveBoxes Glove boxes allow the user to perform operations in an atmosphere 8 University Corporation for Atmospheric Research PO Box 3000 Boulder, Colorado 80307 Geosciences...

  20. Oxygen detected in atmosphere of Saturn's moon Dione

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

    Oxygen detected in atmosphere of Saturn's moon Dione Oxygen detected in atmosphere of Saturn's moon Dione Scientists and an international research team have announced discovery of...

  1. atmospheric modeling system: Topics by E-print Network

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

    14 Causes and implications of persistent atmospheric carbon dioxide biases in Earth System Models University of California eScholarship Repository Summary: Atmosphere and Ocean...

  2. atmospheric co2 content: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  3. atmospheric chemistry simulations: Topics by E-print Network

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

    Environmental Sciences and Ecology Websites Summary: , nitrogen and oxygen The Greenhouse Effect Atmospheric Aerosols Atmospheric chemical kinetics including and oral reports to...

  4. atmospheric sciences exposure: Topics by E-print Network

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

    annual reviews of faculty performance in accordance 8 Space Science : Atmosphere Greenhouse Effect Physics Websites Summary: Space Science : Atmosphere Greenhouse Effect Part-5a...

  5. atmospheric chemistry project: Topics by E-print Network

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

    Environmental Sciences and Ecology Websites Summary: , nitrogen and oxygen The Greenhouse Effect Atmospheric Aerosols Atmospheric chemical kinetics including and oral reports to...

  6. atmospheric co2 concentrations: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  7. atmospheric co2 concentration: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  8. atmospheric co2 laser: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  9. atmospheric loading effects: Topics by E-print Network

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

    large solar proton Paris-Sud XI, Universit de 7 Space Science : Atmosphere Greenhouse Effect Physics Websites Summary: Space Science : Atmosphere Greenhouse Effect Part-5a...

  10. atmospheric chemistry programme: Topics by E-print Network

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

    Environmental Sciences and Ecology Websites Summary: , nitrogen and oxygen The Greenhouse Effect Atmospheric Aerosols Atmospheric chemical kinetics including and oral reports to...

  11. atmospheric co2 measurements: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  12. atmospheric co2 variations: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  13. atmospheric chemistry experiment: Topics by E-print Network

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

    Environmental Sciences and Ecology Websites Summary: , nitrogen and oxygen The Greenhouse Effect Atmospheric Aerosols Atmospheric chemical kinetics including and oral reports to...

  14. atmospheric science people: Topics by E-print Network

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

    annual reviews of faculty performance in accordance 9 Space Science : Atmosphere Greenhouse Effect Physics Websites Summary: Space Science : Atmosphere Greenhouse Effect Part-5a...

  15. atmospheric chemistry: Topics by E-print Network

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

    Environmental Sciences and Ecology Websites Summary: , nitrogen and oxygen The Greenhouse Effect Atmospheric Aerosols Atmospheric chemical kinetics including and oral reports to...

  16. atmospheric sciences: Topics by E-print Network

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

    annual reviews of faculty performance in accordance 8 Space Science : Atmosphere Greenhouse Effect Physics Websites Summary: Space Science : Atmosphere Greenhouse Effect Part-5a...

  17. atmospheric co2 mixing: Topics by E-print Network

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

    Of Physics Version 4 Gerlich and Ralf D. Tscheuschner Abstract The atmospheric greenhouse effect, an idea that many authors Of The Atmospheric CO2 Greenhouse Effects . . . 3...

  18. atmospheric aerosols basic: Topics by E-print Network

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

    of atmospheric aerosol. Aplin, KL 2012-01-01 13 1. Introduction The atmospheric greenhouse effect is the basic mechanism Environmental Sciences and Ecology Websites Summary: 1....

  19. atmospheric deposition microbial: Topics by E-print Network

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

    Mercury in the Global Atmosphere: Chemistry, deposition, and land-atmosphere interactions Environmental Management and Restoration Websites Summary: Mercury in the Global...

  20. atmospheric deposition nutrient: Topics by E-print Network

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

    Mercury in the Global Atmosphere: Chemistry, deposition, and land-atmosphere interactions Environmental Management and Restoration Websites Summary: Mercury in the Global...

  1. Visualizing Storms from NCAR's Atmosphere Model at NERSC

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

    Atmosphere Model Visualizing Storms from NCAR's Atmosphere Model CCSM-sprabhat.png Global warming will likely change the statistics of tropical cyclones and hurricanes. In this...

  2. Optical atomic magnetometer

    DOE Patents [OSTI]

    Budker, Dmitry; Higbie, James; Corsini, Eric P

    2013-11-19T23:59:59.000Z

    An optical atomic magnetometers is provided operating on the principles of nonlinear magneto-optical rotation. An atomic vapor is optically pumped using linearly polarized modulated light. The vapor is then probed using a non-modulated linearly polarized light beam. The resulting modulation in polarization angle of the probe light is detected and used in a feedback loop to induce self-oscillation at the resonant frequency.

  3. Prismatic optical display

    DOE Patents [OSTI]

    Veligdan, James T.; DeSanto, Leonard; Brewster, Calvin

    2004-06-29T23:59:59.000Z

    A spatially modulated light beam is projected, reflected, and redirected through a prismatic optical panel to form a video image for direct viewing thereon.

  4. Optical theorem and unitarity

    E-Print Network [OSTI]

    Valeriy Nazaruk

    2014-03-20T23:59:59.000Z

    It is shown that an application of optical theorem for the non-unitary S-matrix can lead to the qualitative error in the result.

  5. Optical limiting materials

    DOE Patents [OSTI]

    McBranch, Duncan W. (Santa Fe, NM); Mattes, Benjamin R. (Santa Fe, NM); Koskelo, Aaron C. (Los Alamos, NM); Heeger, Alan J. (Santa Barbara, CA); Robinson, Jeanne M. (Los Alamos, NM); Smilowitz, Laura B. (Los Alamos, NM); Klimov, Victor I. (Los Alamos, NM); Cha, Myoungsik (Goleta, CA); Sariciftci, N. Serdar (Santa Barbara, CA); Hummelen, Jan C. (Groningen, NL)

    1998-01-01T23:59:59.000Z

    Optical limiting materials. Methanofullerenes, fulleroids and/or other fullerenes chemically altered for enhanced solubility, in liquid solution, and in solid blends with transparent glass (SiO.sub.2) gels or polymers, or semiconducting (conjugated) polymers, are shown to be useful as optical limiters (optical surge protectors). The nonlinear absorption is tunable such that the energy transmitted through such blends saturates at high input energy per pulse over a wide range of wavelengths from 400-1100 nm by selecting the host material for its absorption wavelength and ability to transfer the absorbed energy into the optical limiting composition dissolved therein. This phenomenon should be generalizable to other compositions than substituted fullerenes.

  6. LSST Camera Optics Design

    SciTech Connect (OSTI)

    Riot, V J; Olivier, S; Bauman, B; Pratuch, S; Seppala, L; Gilmore, D; Ku, J; Nordby, M; Foss, M; Antilogus, P; Morgado, N

    2012-05-24T23:59:59.000Z

    The Large Synoptic Survey Telescope (LSST) uses a novel, three-mirror, telescope design feeding a camera system that includes a set of broad-band filters and three refractive corrector lenses to produce a flat field at the focal plane with a wide field of view. Optical design of the camera lenses and filters is integrated in with the optical design of telescope mirrors to optimize performance. We discuss the rationale for the LSST camera optics design, describe the methodology for fabricating, coating, mounting and testing the lenses and filters, and present the results of detailed analyses demonstrating that the camera optics will meet their performance goals.

  7. Adaptive control for Mars atmospheric flight

    E-Print Network [OSTI]

    Restrepo, Carolina Isabel

    2009-05-15T23:59:59.000Z

    landing accuracy requirements for a manned space vehicle make it necessary to ?y a controlled entry trajectory rather than a more robust ballistic entry trajectory used for some robotic missions. The large variations in Mars atmospheric properties make a...

  8. Composition and Reactions of Atmospheric Aerosol Particles

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

    large portion of the microscopic particles floating in the air originate from incomplete combustion of coal and oil and from dust storms. Once in the atmosphere, they can have...

  9. HYPERsensarium : an archive of atmospheric conditions

    E-Print Network [OSTI]

    Shaw, Kelly E. (Kelly Evelyn)

    2013-01-01T23:59:59.000Z

    HYPERsensarium proposes a tangible interface of atmospheres for public experience through an archive of historical and projected weathers. While architecture's purpose has long been to act as the technical boundary between ...

  10. The porous atmosphere of eta Carinae

    E-Print Network [OSTI]

    Nir J. Shaviv

    2000-02-09T23:59:59.000Z

    We analyze the wind generated by the great 20 year long super-Eddington outburst of eta-Carinae. We show that using classical stellar atmospheres and winds theory, it is impossible to construct a consistent wind model in which a sufficiently small amount of mass, like the one observed, is shed. One expects the super-Eddington luminosity to drive a thick wind with a mass loss rate substantially higher than the observed one. The easiest way to resolve the inconsistency is if we alleviate the implicit notion that atmospheres are homogeneous. An inhomogeneous atmosphere, or "porous", allows more radiation to escape while exerting a smaller average force. Consequently, such an atmosphere yields a considerably lower mass loss rate for the same total luminosity. Moreover, all the applications of the Eddington Luminosity as a strict luminosity limit should be revised, or at least reanalyzed carefully.

  11. Space Science: Atmospheres Evolution of planets

    E-Print Network [OSTI]

    Johnson, Robert E.

    ;Atmospheres / Evolution Heat Sources Compressional Energy Trapped Radioactive Material Tidal Interactions, same A) the surface temperature,Tg, increases. WOW! Simple #12;Temperature vs. time in an Early Epoch

  12. MIDDLE ATMOSPHERE DYNAMICS AT707 (3 credits)

    E-Print Network [OSTI]

    ., Holton, J. R., Leovy, C. B., Academic Press, 489 pp. · Atmospheric and Oceanic Fluid Dynamics, 2006 Review Articles: · Haynes, P. H., 2005: Stratospheric Dynamics. Annu. Rev. Fluid Mech., 37, 263­ 293

  13. Lookup tables to compute high energy cosmic ray induced atmospheric ionization and changes in atmospheric chemistry

    E-Print Network [OSTI]

    Dimitra Atri; Adrian L. Melott; Brian C. Thomas

    2010-05-03T23:59:59.000Z

    A variety of events such as gamma-ray bursts and supernovae may expose the Earth to an increased flux of high-energy cosmic rays, with potentially important effects on the biosphere. Existing atmospheric chemistry software does not have the capability of incorporating the effects of substantial cosmic ray flux above 10 GeV . An atmospheric code, the NASA-Goddard Space Flight Center two-dimensional (latitude, altitude) time-dependent atmospheric model (NGSFC), is used to study atmospheric chemistry changes. Using CORSIKA, we have created tables that can be used to compute high energy cosmic ray (10 GeV - 1 PeV) induced atmospheric ionization and also, with the use of the NGSFC code, can be used to simulate the resulting atmospheric chemistry changes. We discuss the tables, their uses, weaknesses, and strengths.

  14. JournalofGeophysicalResearch: Atmospheres RESEARCH ARTICLE

    E-Print Network [OSTI]

    to optical frequencies, extending to X-rays and gamma rays. The electromagnetic pulse associated to its abundance in nature. Lightning processes radiate impulsive electromagnetic waves from DC

  15. Air Activation Following an Atmospheric Explosion

    SciTech Connect (OSTI)

    Lowrey, Justin D.; McIntyre, Justin I.; Prichard, Andrew W.; Gesh, Christopher J.

    2013-03-13T23:59:59.000Z

    In addition to thermal radiation and fission products, nuclear explosions result in a very high flux of unfissioned neutrons. Within an atmospheric nuclear explosion, these neutrons can activate the various elemental components of natural air, potentially adding to the radioactive signature of the event as a whole. The goal of this work is to make an order-of-magnitude estimate of the total amount of air activation products that can result from an atmospheric nuclear explosion.

  16. Trace analysis of atmospheric organic bases

    E-Print Network [OSTI]

    Clark, Dwayne C.

    1984-01-01T23:59:59.000Z

    chromatographic fractions for NS analyses ( 121) and its use as a thin layer chromatography (TLC) adsorbent ( 122). The National Institute of Occupational Safety and Health (NIOSH) recommends its use in the analysis of many industrial vapors ( 113 - 120... analysis of atmospheric organic bases were investigated; the study included (1) the analysis of submarine charcoal filter bed samples for nitrogen bases and (2) the use of metallic tetraphenylporphines (TPP) as specific adsorbents for atmospheric...

  17. Quantum light in the turbulent atmosphere

    E-Print Network [OSTI]

    A. A. Semenov; W. Vogel

    2009-08-12T23:59:59.000Z

    Nonclassical properties of light propagating through the turbulent atmosphere are studied. We demonstrate by numerical simulation that the probability distribution of the transmission coefficient, which characterizes the effects of the atmosphere on the quantum state of light, can be reconstructed by homodyne detection. Nonclassical photon-statistics and, more generally, nonclassical Glauber-Sudarshan functions appear to be more robust against turbulence for weak light fields rather than for bright ones.

  18. Atmospheric State, Cloud Microphysics and Radiative Flux

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mace, Gerald

    Atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates for the ARM Southern Great Plains (SGP) site. The data represent a characterization of the physical state of the atmospheric column compiled on a five-minute temporal and 90m vertical grid. Sources for this information include raw measurements, cloud property and radiative retrievals, retrievals and derived variables from other third-party sources, and radiative calculations using the derived quantities.

  19. AN INTRODUCTION TO QUANTUM OPTICS...

    E-Print Network [OSTI]

    Palffy-Muhoray, Peter

    AN INTRODUCTION TO QUANTUM OPTICS... ...the light as you've never seen before... Optics:http://science.howstuffworks.com/laser5.htm #12;5 DEFINITION Quantum Optics: "Quantum optics is a field in quantum physics, dealing OPTICS OPERATORS Light is described in terms of field operators for creation and annihilation of photons

  20. Correlations of atmospheric water ice and dust in the Martian Polar regions

    E-Print Network [OSTI]

    Brown, Adrian J; Scargle, Jeffrey D

    2015-01-01T23:59:59.000Z

    We report on the interannual variability of the atmospheric ice/dust cycle in the Martian polar regions for Mars Years 28-30. We used CRISM emission phase function measurements to derive atmospheric dust optical depths and data from the MARCI instrument to derive atmospheric water ice optical depths. We have used autocorrelation and cross correlation functions in order to quantify the degree to which dust and ice are correlated throughout both polar regions during Mars Years 28-29. We find that in the south polar region, dust has the tendency to "self clear", demonstrated by negative autocorrelation around the central peak. This does not occur in the north polar region. In the south polar region, dust and ice are temporally and spatially anti correlated. In the north polar region, this relationship is reversed, however temporal correlation of northern dust and ice clouds is weak - 6 times weaker than the anticorrelation in the south polar region. Our latitudinal autocorrelation functions allow us to put avera...

  1. Energy transport, overshoot, and mixing in the atmospheres of very cool stars

    E-Print Network [OSTI]

    H. -G. Ludwig

    2002-08-30T23:59:59.000Z

    We constructed hydrodynamical model atmospheres for mid M-type main-, as well as pre-main-sequence objects. Despite the complex chemistry encountered in such cool atmospheres a reasonably accurate representation of the radiative transfer is possible. The detailed treatment of the interplay between radiation and convection in the hydrodynamical models allows to study processes usually not accessible within the framework conventional model atmospheres. In particular, we determined the efficiency of the convective energy transport, and the efficiency of mixing by convective overshoot. The convective transport efficiency expressed in terms of an equivalent mixing-length parameter amounts to values around ~2 in the optically thick, and ~2.8 in the optically thin regime. The thermal structure of the formally convectively stable layers is little affected by convective overshoot and wave heating, i.e. stays close to radiative equilibrium. Mixing by convective overshoot shows an exponential decline with geometrical distance from the Schwarzschild stability boundary. The scale height of the decline varies with gravitational acceleration roughly as g^(-1/2), with 0.5 pressure scale heights at log(g)=5.0.

  2. Experimental Verification of the Van Vleck Nature of Long-Range Ferromagnetic Order in the Vanadium-Doped Three-Dimensional Topological Insulator Sb[subscript 2]Te[subscript 3

    E-Print Network [OSTI]

    Li, Mingda

    We demonstrate by high resolution low temperature electron energy loss spectroscopy (EELS) measurements that the long range ferromagnetic (FM) order in the vanadium- (V-)doped topological insulator Sb[subscript 2]Te[subscript ...

  3. Flexible optical panel

    DOE Patents [OSTI]

    Veligdan, James T. (Manorville, NY)

    2001-01-01T23:59:59.000Z

    A flexible optical panel includes laminated optical waveguides, each including a ribbon core laminated between cladding, with the core being resilient in the plane of the core for elastically accommodating differential movement thereof to permit winding of the panel in a coil.

  4. Multimode optical fiber

    DOE Patents [OSTI]

    Bigot-Astruc, Marianne; Molin, Denis; Sillard, Pierre

    2014-11-04T23:59:59.000Z

    A depressed graded-index multimode optical fiber includes a central core, an inner depressed cladding, a depressed trench, an outer depressed cladding, and an outer cladding. The central core has an alpha-index profile. The depressed claddings limit the impact of leaky modes on optical-fiber performance characteristics (e.g., bandwidth, core size, and/or numerical aperture).

  5. Apollo Ring Optical Switch

    SciTech Connect (OSTI)

    Maestas, J.H.

    1987-03-01T23:59:59.000Z

    An optical switch was designed, built, and installed at Sandia National Laboratories in Albuquerque, New Mexico, to facilitate the integration of two Apollo computer networks into a single network. This report presents an overview of the optical switch as well as its layout, switch testing procedure and test data, and installation.

  6. Digital optical conversion module

    DOE Patents [OSTI]

    Kotter, D.K.; Rankin, R.A.

    1988-07-19T23:59:59.000Z

    A digital optical conversion module used to convert an analog signal to a computer compatible digital signal including a voltage-to-frequency converter, frequency offset response circuitry, and an electrical-to-optical converter. Also used in conjunction with the digital optical conversion module is an optical link and an interface at the computer for converting the optical signal back to an electrical signal. Suitable for use in hostile environments having high levels of electromagnetic interference, the conversion module retains high resolution of the analog signal while eliminating the potential for errors due to noise and interference. The module can be used to link analog output scientific equipment such as an electrometer used with a mass spectrometer to a computer. 2 figs.

  7. Fiber optic hydrophone

    DOE Patents [OSTI]

    Kuzmenko, P.J.; Davis, D.T.

    1994-05-10T23:59:59.000Z

    A miniature fiber optic hydrophone based on the principles of a Fabry-Perot interferometer is disclosed. The hydrophone, in one embodiment, includes a body having a shaped flexible bladder at one end which defines a volume containing air or suitable gas, and including a membrane disposed adjacent a vent. An optical fiber extends into the body with one end terminating in spaced relation to the membrane. Acoustic waves in the water that impinge on the bladder cause the pressure of the volume therein to vary causing the membrane to deflect and modulate the reflectivity of the Fabry-Perot cavity formed by the membrane surface and the cleaved end of the optical fiber disposed adjacent to the membrane. When the light is transmitted down the optical fiber, the reflected signal is amplitude modulated by the incident acoustic wave. Another embodiment utilizes a fluid filled volume within which the fiber optic extends. 2 figures.

  8. Optical amplifier-powered quantum optical amplification

    E-Print Network [OSTI]

    John Jeffers

    2011-05-16T23:59:59.000Z

    I show that an optical amplifier, when combined with photon subtraction, can be used for quantum state amplification, adding noise at a level below the standard minimum. The device could be used to significantly decrease the probability of incorrectly identifying coherent states chosen from a finite set.

  9. New nonlinear mechanisms of midlatitude atmospheric low-frequency variability

    E-Print Network [OSTI]

    and Atmospheric Research Utrecht, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands Abstract

  10. Method of fabricating optical waveguides by ion implantation doping

    DOE Patents [OSTI]

    Appleton, B.R.; Ashley, P.R.; Buchal, C.J.

    1987-03-24T23:59:59.000Z

    A method for fabricating high-quality optical waveguides in optical quality oxide crystals by ion implantation doping and controlled epitaxial recrystallization is provided. Masked LiNbO/sub 3/ crystals are implanted with high concentrations of Ti dopant at ion energies of about 360 keV while maintaining the crystal near liquid nitrogen temperature. Ion implantation doping produces an amorphous, Ti-rich nonequilibrium phase in the implanted region. Subsequent thermal annealing in a water-saturated oxygen atmosphere at up to 1000/degree/C produces solid-phase epitaxial regrowth onto the crystalline substrate. A high-quality crystalline layer results which incorporates the Ti into the crystal structure at much higher concentrations than is possible by standard diffusion techniques, and this implanted region has excellent optical waveguiding properties.

  11. The Atmospheric Monitoring System of the JEM-EUSO Space Mission

    E-Print Network [OSTI]

    Frias, M D Rodriguez; Bozzo, E; del Peral, L; Neronov, A; Wada, S

    2015-01-01T23:59:59.000Z

    An Atmospheric Monitoring System (AMS) is a mandatory and key device of a space-based mission which aims to detect Ultra-High Energy Cosmic Rays (UHECR) and Extremely-High Energy Cosmic Rays (EHECR) from Space. JEM-EUSO has a dedicated atmospheric monitoring system that plays a fundamental role in our understanding of the atmospheric conditions in the Field of View (FoV) of the telescope. Our AMS consists of a very challenging space infrared camera and a LIDAR device, that are being fully designed with space qualification to fulfil the scientific requirements of this space mission. The AMS will provide information of the cloud cover in the FoV of JEM-EUSO, as well as measurements of the cloud top altitudes with an accuracy of 500 m and the optical depth profile of the atmosphere transmittance in the direction of each air shower with an accuracy of 0.15 degree and a resolution of 500 m. This will ensure that the energy of the primary UHECR and the depth of maximum development of the EAS ( Extensive Air Shower)...

  12. Atmospheric Modelling for Neptune's Methane D/H Ratio - Preliminary Results

    E-Print Network [OSTI]

    Cotton, Daniel V; Bott, Kimberly; Bailey, Jeremy

    2015-01-01T23:59:59.000Z

    The ratio of deuterium to hydrogen (D/H ratio) of Solar System bodies is an important clue to their formation histories. Here we fit a Neptunian atmospheric model to Gemini Near Infrared Spectrograph (GNIRS) high spectral resolution observations and determine the D/H ratio in methane absorption in the infrared H-band ($\\sim$ 1.6 {\\mu}m). The model was derived using our radiative transfer software VSTAR (Versatile Software for the Transfer of Atmospheric Radiation) and atmospheric fitting software ATMOF (ATMOspheric Fitting). The methane line list used for this work has only become available in the last few years, enabling a refinement of earlier estimates. We identify a bright region on the planetary disc and find it to correspond to an optically thick lower cloud. Our preliminary determination of CH$_{\\rm 3}$D/CH$_{\\rm 4}$ is 3.0$\\times10^{-4}$, which is in line with the recent determination of Irwin et al. (2014) of 3.0$^{+1.0}_{-0.9}\\sim\\times10^{-4}$, made using the same model parameters and line list but...

  13. Ellerman bombs—evidence for magnetic reconnection in the lower solar atmosphere

    SciTech Connect (OSTI)

    Nelson, C. J.; Doyle, J. G.; Madjarska, M. S. [Armagh Observatory, College Hill, Armagh BT61 9DG (United Kingdom); Shelyag, S. [Monash Centre for Astrophysics, School of Mathematical Sciences, Monash University, Clayton, VIC 3800 (Australia); Mathioudakis, M. [Astrophysical Research Centre, School of Mathematics and Physics, Queen's University, Belfast BT7 1NN (United Kingdom); Uitenbroek, H. [National Solar Observatory, Sacramento Peak, P.O. Box 62, Sunpsot, NM 88349 (United States); Erdélyi, R. [Solar Physics and Space Plasma Research Centre, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

    2013-12-20T23:59:59.000Z

    The presence of photospheric magnetic reconnection has long been thought to give rise to short and impulsive events, such as Ellerman bombs (EBs) and Type II spicules. In this article, we combine high-resolution, high-cadence observations from the Interferometric BIdimensional Spectrometer and Rapid Oscillations in the Solar Atmosphere instruments at the Dunn Solar Telescope, National Solar Observatory, New Mexico, with co-aligned Solar Dynamics Observatory Atmospheric Imaging Assembly and Hinode Solar Optical Telescope (SOT) data to observe small-scale events situated within an active region. These data are then compared with state-of-the-art numerical simulations of the lower atmosphere made using the MURaM code. It is found that brightenings, in both the observations and the simulations, of the wings of the H? line profile, interpreted as EBs, are often spatially correlated with increases in the intensity of the Fe I ?6302.5 line core. Bipolar regions inferred from Hinode/SOT magnetic field data show evidence of flux cancellation associated, co-spatially, with these EBs, suggesting that magnetic reconnection could be a driver of these high-energy events. Through the analysis of similar events in the simulated lower atmosphere, we are able to infer that line profiles analogous to the observations occur co-spatially with regions of strong opposite-polarity magnetic flux. These observed events and their simulated counterparts are interpreted as evidence of photospheric magnetic reconnection at scales observable using current observational instrumentation.

  14. THE INFLUENCE OF ATMOSPHERIC SCATTERING AND ABSORPTION ON OHMIC DISSIPATION IN HOT JUPITERS

    SciTech Connect (OSTI)

    Heng, Kevin [ETH Zuerich, Institute for Astronomy, Wolfgang-Pauli-Strasse 27, CH-8093 Zuerich (Switzerland)

    2012-03-20T23:59:59.000Z

    Using semi-analytical, one-dimensional models, we elucidate the influence of scattering and absorption on the degree of Ohmic dissipation in hot Jovian atmospheres. With the assumption of Saha equilibrium, the variation in temperature is the main driver of the variations in the electrical conductivity, induced current, and Ohmic power dissipated. Atmospheres possessing temperature inversions tend to dissipate most of the Ohmic power superficially, at high altitudes, whereas those without temperature inversions are capable of greater dissipation deeper down. Scattering in the optical range of wavelengths tends to cool the lower atmosphere, thus reducing the degree of dissipation at depth. Purely absorbing cloud decks (in the infrared), of a finite extent in height, allow for localized reductions in dissipation and may reverse a temperature inversion if they are dense and thick enough, thus greatly enhancing the dissipation at depth. If Ohmic dissipation is the mechanism for inflating hot Jupiters, then variations in the atmospheric opacity (which may be interpreted as arising from variations in metallicity and cloud/haze properties) and magnetic field strength naturally produce a scatter in the measured radii at a given strength of irradiation. Future work will determine if these effects are dominant over evolutionary effects, which also contribute a scatter to the measured radii.

  15. Thermoelectric power of Bi and Bi{sub 1{minus}x}Sb{sub x} alloy thin films and superlattices grown by MBE

    SciTech Connect (OSTI)

    Cho, S.; DiVenere, A.; Wong, G.K.; Ketterson, J.B.; Meyer, J.R.; Hoffman, C.A.

    1997-07-01T23:59:59.000Z

    The authors have measured the thermoelectric power (TEP) of MBE-grown epitaxial Bi and Bi{sub 1{minus}x} alloy thin films and superlattices as a function of temperature in the range 20--300 K. They have observed that the TEP of a Bi thin film of 1 {micro}m thickness is in good agreement with the bulk single crystal value and that the TEPs for superlattices with 400 {angstrom} and 800 {angstrom} Bi well thicknesses are enhanced over the bulk values. For x = 0.072 and 0.088 in Bi{sub 1{minus}x}Sb{sub x} thin films showing semiconducting behavior, TEP enhancement was observed by a factor of two. However as Bi or Bi{sub 1{minus}x}Sb{sub x} well thickness decreases in superlattice geometry, the TEP decreases, which may be due to unintentional p-type doping.

  16. 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. [Physics Department, Faculty of Science , Assiut University, Assiut, P.O. Box 71516 (Egypt); Moharram, A. H. [Faculty of Science, King Abdul Aziz Univ., Rabigh Branch, P.O. Box 433 (Saudi Arabia)

    2013-12-16T23:59:59.000Z

    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.

  17. Inductively Coupled Plasma Etching in ICl- and IBr-Based Chemistries: Part II. InP, InSb, InGaP and InGaAs

    SciTech Connect (OSTI)

    Abernathy, C.R.; Cho, H.; Hahn, Y.B.; Hays, D.C.; Hobson, W.S.; Jung, K.B.; Lambers, E.S.; Pearton, S.J.; Shul, R.J.

    1998-11-23T23:59:59.000Z

    A parametric study of Inductively Coupled Plasma etching of InP, InSb, InGaP and InGaAs has been carried out in IC1/Ar and IBr/Ar chemistries. Etch rates in excess of 3.1 prrdmin for InP, 3.6 prnh-nin for InSb, 2.3 pm/min for InGaP and 2.2 ~rrdmin for InGaAs were obtained in IBr/Ar plasmas. The ICP etching of In-based materials showed a general tendency: the etch rates increased substantially with increasing the ICP source power and rf chuck power in both chemistries, while they decreased with increasing chamber pressure. The IBr/Ar chemistry typically showed higher etch rates than IC1/Ar, but the etched surface mophologies were fairly poor for both chemistries.

  18. An Efficient Approach for Optical Radiative Transfer Tomography using the Spherical Harmonics Discrete Ordinates Method

    E-Print Network [OSTI]

    Levis, Aviad; Aides, Amit; Davis, Anthony B

    2015-01-01T23:59:59.000Z

    This paper introduces a method to preform optical tomography, using 3D radiative transfer as the forward model. We use an iterative approach predicated on the Spherical Harmonics Discrete Ordinates Method (SHDOM) to solve the optimization problem in a scalable manner. We illustrate with an application in remote sensing of a cloudy atmosphere.

  19. Internal solitary waves in the Coastal Mixing and Optics 1996 experiment: Multimodal structure and

    E-Print Network [OSTI]

    Kurapov, Alexander

    and resuspension D. J. Bogucki Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami in sediment resuspension during the Coastal Mixing and Optics 1996 (CMO 96) experiment are reported. The largest resuspension events observed in the experiment can be related to retarded flow under the wave

  20. Dynamical scaling properties of nanoporous undoped and Sb-doped SnO{sub 2} supported thin films during tri- and bidimensional structure coarsening

    SciTech Connect (OSTI)

    Santilli, C. V.; Rizzato, A. P.; Pulcinelli, S. H.; Craievich, A. F. [Instituto de Quimica/UNESP, P.O. Box 355, Araraquara, Sao Paulo 14800-900 (Brazil); Instituto de Fisica/USP, P.O. Box 66318, Sao Paulo, Sao Paulo 05315-970, (Brazil)

    2007-05-15T23:59:59.000Z

    The coarsening of the nanoporous structure developed in undoped and 3% Sb-doped SnO{sub 2} sol-gel dip-coated films deposited on a mica substrate was studied by time-resolved small-angle x-ray scattering (SAXS) during in situ isothermal treatments at 450 and 650 deg. C. The time dependence of the structure function derived from the experimental SAXS data is in reasonable agreement with the predictions of the statistical theory of dynamical scaling, thus suggesting that the coarsening process in the studied nanoporous structures exhibits dynamical self-similar properties. The kinetic exponents of the power time dependence of the characteristic scaling length of undoped SnO{sub 2} and 3% Sb-doped SnO{sub 2} films are similar ({alpha}{approx_equal}0.09), this value being invariant with respect to the firing temperature. In the case of undoped SnO{sub 2} films, another kinetic exponent, {alpha}{sup '}, corresponding to the maximum of the structure function was determined to be approximately equal to three times the value of the exponent {alpha}, as expected for the random tridimensional coarsening process in the dynamical scaling regime. Instead, for 3% Sb-doped SnO{sub 2} films fired at 650 deg. C, we have determined that {alpha}{sup '}{approx_equal}2{alpha}, thus suggesting a bidimensional coarsening of the porous structure. The analyses of the dynamical scaling functions and their asymptotic behavior at high q (q being the modulus of the scattering vector) provided additional evidence for the two-dimensional features of the pore structure of 3% Sb-doped SnO{sub 2} films. The presented experimental results support the hypotheses of the validity of the dynamic scaling concept to describe the coarsening process in anisotropic nanoporous systems.