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Sample records for highly lambertian reflector

  1. Recovery Act: Low-Cost, Highly Lambertian Reflector Composite...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Technical Report: Recovery Act: Low-Cost, Highly Lambertian Reflector Composite For Improved LED Fixture Efficiency and Lifetime Citation Details ...

  2. Recovery Act: Low-Cost, Highly Lambertian Reflector Composite...

    Office of Scientific and Technical Information (OSTI)

    Reflector Composite For Improved LED Fixture Efficiency and Lifetime Teather, Eric 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; 36 MATERIALS SCIENCE The overall...

  3. Recovery Act: Low-Cost, Highly Lambertian Reflector Composite...

    Office of Scientific and Technical Information (OSTI)

    Close Cite: Bibtex Format Close 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document for ...

  4. Recovery Act: Low-Cost, Highly Lambertian Reflector Composite...

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; 36 MATERIALS SCIENCE Word Cloud More Like This Full Text ...

  5. Project Profile: High Performance Reflector Panels for CSP Assemblies |

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

    Department of Energy Concentrating Solar Power » Project Profile: High Performance Reflector Panels for CSP Assemblies Project Profile: High Performance Reflector Panels for CSP Assemblies PPG logo PPG, under the CSP R&D FOA, is aiming to develop and commercialize large-area second-surface glass mirrors that are superior in value, cost, and performance, to existing mirrors on the market today. Approach Photo of a metal stand with flat square-shaped pieces lined up in three rows. This

  6. Advanced Manufacture of Second-Surface, Silvered Glass Reflectors for High-Performance, Low-Cost CSP Collector Systems

    Broader source: Energy.gov [DOE]

    Advanced Manufacture of Second-Surface, Silvered Glass Reflectors for High-Performance, Low-Cost CSP Collector Systems

  7. Damage thresholds of thin film materials and high reflectors at 248 nm

    SciTech Connect (OSTI)

    Rainer, F.; Lowdermilk, W.H.; Milam, D.; Carniglia, C.K.; Hart, T.T.; Lichtenstein, T.L.

    1982-01-01

    Twenty-ns, 248-nm KrF laser pulses were used to measure laser damage thresholds for halfwave-thick layers of 15 oxide and fluoride coating materials, and for high reflectance coatings made with 13 combinations of these materials. The damage thresholds of the reflectors and single-layer films were compared to measurements of several properties of the halfwave-thick films to determine whether measurements of these properties of single-layer films to determine whether measurements of these properties of single-layer films were useful for identifying materials for fabrication of damage resistant coatings.

  8. High efficiency epitaxial optical reflector solar cells. Final subcontract report, 1 January 1990--31 October 1992

    SciTech Connect (OSTI)

    Dapkus, P.D.; Hummel, S.G.

    1993-08-01

    This report describes work to test the feasibility of a new solar cell concept -- the epitaxial optical reflector (EOR) solar cell. This cell concept alters current designs for high efficiency cells by changing the optical absorption efficiency of single cells. The change is introduced by the use an epitaxial multilayer reflector as an integral part of the cell to increase the optical path length of certain wavelengths of light in the cell. These changes are expected to increase the open circuit voltage at which power is extracted from the cell. The program is designed to test the feasibility of the use of a broad band epitaxial multilayer reflector grown as an integral part of the device structure to reflect the near-band-edge light back through the device for a second absorption pass. This second pass allows the design of a solar cell with a thinner base, and the use of the epitaxial reflector as a heterojunction carrier-reflecting barrier at the rear of the device. The thinner cell design and altered carrier profile that results from the light- and carrier-reflecting barrier will decrease the carrier concentration gradient and increase the open circuit voltage. The program is structured to have three tasks: (1) Solar Cell and Reflector Modeling, (2) Materials Growth and Optimization, and (3) Solar Cell Fabrication and Characterization.

  9. Reactivity Accountability Attributed to Reflector Poisons in the High Flux Isotope Reactor

    SciTech Connect (OSTI)

    Chandler, David; Maldonado, G Ivan; Primm, Trent

    2009-12-01

    The objective of this study is to develop a methodology to predict the reactivity impact as a function of outage time between cycles of 3He, 6Li, and other poisons in the High Flux Isotope Reactor s (HFIR) beryllium reflector. The reactivity worth at startup of the HFIR has been incorrectly predicted in the past after the reactor has been shut-down for long periods of time. The incorrect prediction was postulated to be due to the erroneous calculation of 3He buildup in the beryllium reflector. It is necessary to develop a better estimate of the start-of-cycle symmetric critical control element positions since if the estimated and actual symmetrical critical control element positions differ by more than $1.55 in reactivity (approximately one-half inch in control element startup position), HFIR is to be shutdown and a technical evaluation is performed to resolve the discrepancy prior to restart. 3He is generated and depleted during operation, but during an outage, the depletion of 3He ceases because it is a stable isotope. 3He is born from the radioactive decay of tritium, and thus the concentration of 3He increases during shutdown. SCALE, specifically the TRITON and CSAS5 control modules including the KENO V.A, COUPLE, and ORIGEN functional modules were utilized in this study. An equation relating the down time (td) to the change in symmetric control element position was generated and validated against measurements for approximately 40 HFIR operating cycles. The newly-derived correlation was shown to improve accuracy of predictions for long periods of down time.

  10. Advanced Manufacture of Reflectors

    Broader source: Energy.gov [DOE]

    The Advance Manufacture of Reflectors fact sheet describes a SunShot Initiative project being conducted research team led by the University of Arizona, which is working to develop a novel method for shaping float glass. The technique developed by this research team can drastically reduce the time required for the shaping step. By enabling mass production of solar concentrating mirrors at high speed, this project should lead to improved performance and as much as a 40% reduction in manufacturing costs for reflectors made in very high volume.

  11. Advanced Manufacture of Second-Surface, Silvered Glass Reflectors...

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

    Manufacture of Second-Surface, Silvered Glass Reflectors for High-Performance, Low-Cost CSP Collector Systems Advanced Manufacture of Second-Surface, Silvered Glass Reflectors for ...

  12. Design of Semiconductor-Based Back Reflectors for High Voc Monolithic Multijunction Solar Cells: Preprint

    SciTech Connect (OSTI)

    Garcia, I.; Geisz, J.; Steiner, M.; Olson, J.; Friedman, D.; Kurtz, S.

    2012-06-01

    State-of-the-art multijunction cell designs have the potential for significant improvement before going to higher number of junctions. For example, the Voc can be substantially increased if the photon recycling taking place in the junctions is enhanced. This has already been demonstrated (by Alta Devices) for a GaAs single-junction cell. For this, the loss of re-emitted photons by absorption in the underlying layers or substrate must be minimized. Selective back surface reflectors are needed for this purpose. In this work, different architectures of semiconductor distributed Bragg reflectors (DBR) are assessed as the appropriate choice for application in monolithic multijunction solar cells. Since the photon re-emission in the photon recycling process is spatially isotropic, the effect of the incident angle on the reflectance spectrum is of central importance. In addition, the DBR structure must be designed taking into account its integration into the monolithic multijunction solar cells, concerning series resistance, growth economics, and other issues. We analyze the tradeoffs in DBR design complexity with all these requirements to determine if such a reflector is suitable to improve multijunction solar cells.

  13. STARTUP REACTIVITY ACCOUNTABILITY ATTRIBUTED TO ISOTOPIC TRANSMUTATIONS IN THE IRRADIATED BERYLLIUM REFLECTOR OF THE HIGH FLUX ISTOTOPE REACTOR

    SciTech Connect (OSTI)

    Chandler, David [ORNL] [ORNL; Maldonado, G Ivan [ORNL] [ORNL; Primm, Trent [ORNL] [ORNL

    2010-01-01

    The objective of this study is to develop a methodology to predict the reactivity impact as a function of outage time between cycles of 3He, 6Li, and other poisons in the High Flux Isotope Reactor s (HFIR) beryllium reflector. The reactivity worth at startup of the HFIR has been incorrectly predicted in the past after the reactor has been shut-down for long periods of time. The incorrect prediction was postulated to be due to the erroneous calculation of 3He buildup in the beryllium reflector. It is necessary to develop a better estimate of the start-of-cycle symmetric critical control element positions since if the estimated and actual symmetrical critical control element positions differ by more than $1.55 in reactivity (approximately one-half inch in control element startup position), HFIR is to be shutdown and a technical evaluation is performed to resolve the discrepancy prior to restart. 3He is generated and depleted during operation, but during an outage, the depletion of 3He ceases because it is a stable isotope. 3He is born from the radioactive decay of tritium, and thus the concentration of 3He increases during shutdown. The computer program SCALE, specifically the TRITON and CSAS5 control modules including the KENO V.A, COUPLE, and ORIGEN functional modules were utilized in this study. An equation relating the down time (td) to the change in symmetric control element position was generated and validated against measurements for approximately 40 HFIR operating cycles. The newly-derived correlation was shown to improve accuracy of predictions for long periods of down time.

  14. EA-1911: Energy Conservation Standards for Certain Reflector, Elliptical Reflector, and Bulged Reflector Incandescent Lamps

    Broader source: Energy.gov [DOE]

    This EA will evaluate the environmental impacts of a proposal to amend energy conservation standards for Certain Reflector, Elliptical Reflector, and Bulged Reflector Incandescent Lamps.

  15. Advanced Manufacture of Reflectors

    SciTech Connect (OSTI)

    Angel, Roger

    2014-12-17

    The main project objective has been to develop an advanced gravity sag method for molding large glass solar reflectors with either line or point focus, and with long or short focal length. The method involves taking standard sized squares of glass, 1.65 m x 1.65 m, and shaping them by gravity sag into precision steel molds. The method is designed for high volume manufacture when incorporated into a production line with separate pre-heating and cooling. The performance objectives for the self-supporting glass mirrors made by this project include mirror optical accuracy of 2 mrad root mean square (RMS), requiring surface slope errors <1 mrad rms, a target not met by current production of solar reflectors. Our objective also included development of new methods for rapidly shaping glass mirrors and coating them for higher reflectivity and soil resistance. Reflectivity of 95% for a glass mirror with anti-soil coating was targeted, compared to the present ~94% with no anti-soil coating. Our mirror cost objective is ~$20/m2 in 2020, a significant reduction compared to the present ~$35/m2 for solar trough mirrors produced for trough solar plants. During the first year a custom batch furnace was built to develop the method with high power radiative heating to simulate transfer of glass into a hot slumping zone in a production line. To preserve the original high polish of the float glass on both front and back surfaces, as required for a second surface mirror, the mold surface is machined to the required shape as grooves which intersect the glass at cusps, reducing the mold contact area to significantly less than 1%. The mold surface is gold-plated to reflect thermal radiation. Optical metrology of glass replicas made with the system has been carried out with a novel, custom-built test system. This test provides collimated, vertically-oriented parallel beams from a linear array of co-aligned lasers translated in a perpendicular direction across the reflector. Deviations of

  16. Nuclear reactor reflector

    DOE Patents [OSTI]

    Hopkins, Ronald J.; Land, John T.; Misvel, Michael C.

    1994-01-01

    A nuclear reactor reflector is disclosed that comprises a stack of reflector blocks with vertical water flow passages to cool the reflector. The interface between blocks is opposite support points for reactor fuel rods. Water flows between the reflector and the reactor barrel from passages in a bottom block. The top block contains a flange to limit this flow and the flange has a slot to receive an alignment pin that is welded to the barrel. The pin is held in the slot by two removable shims. Alignment bars extend the length of the stack in slots machined in each block when the stack is assembled.

  17. Nuclear reactor reflector

    DOE Patents [OSTI]

    Hopkins, R.J.; Land, J.T.; Misvel, M.C.

    1994-06-07

    A nuclear reactor reflector is disclosed that comprises a stack of reflector blocks with vertical water flow passages to cool the reflector. The interface between blocks is opposite support points for reactor fuel rods. Water flows between the reflector and the reactor barrel from passages in a bottom block. The top block contains a flange to limit this flow and the flange has a slot to receive an alignment pin that is welded to the barrel. The pin is held in the slot by two removable shims. Alignment bars extend the length of the stack in slots machined in each block when the stack is assembled. 12 figs.

  18. REFLECTOR FOR NEUTRONIC REACTORS

    DOE Patents [OSTI]

    Fraas, A.P.

    1963-08-01

    A reflector for nuclear reactors that comprises an assembly of closely packed graphite rods disposed with their major axes substantially perpendicular to the interface between the reactor core and the reflector is described. Each graphite rod is round in transverse cross section at (at least) its interface end and is provided, at that end, with a coaxial, inwardly tapering hole. (AEC)

  19. Distributed Bragg Reflectors With Reduced Optical Absorption

    DOE Patents [OSTI]

    Klem, John F.

    2005-08-16

    A new class of distributed Bragg reflectors has been developed. These distributed Bragg reflectors comprise interlayers positioned between sets of high-index and low-index quarter-wave plates. The presence of these interlayers is to reduce photon absorption resulting from spatially indirect photon-assisted electronic transitions between the high-index and low-index quarter wave plates. The distributed Bragg reflectors have applications for use in vertical-cavity surface-emitting lasers for use at 1.55 .mu.m and at other wavelengths of interest.

  20. Corrosion protection for silver reflectors

    DOE Patents [OSTI]

    Arendt, Paul N.; Scott, Marion L.

    1991-12-31

    A method of protecting silver reflectors from damage caused by contact with gaseous substances which are often present in the atmosphere and a silver reflector which is so protected. The inventive method comprises at least partially coating a reflector with a metal oxide such as aluminum oxide to a thickness of 15 .ANG. or less.

  1. Nuclear Transmutations in HFIR's Beryllium Reflector and Their Impact on Reactor Operation and Reflector Disposal

    SciTech Connect (OSTI)

    Chandler, David [ORNL; Maldonado, G Ivan [ORNL; Primm, Trent [ORNL; Proctor, Larry Duane [ORNL

    2012-01-01

    The High Flux Isotope Reactor located at the Oak Ridge National Laboratory utilizes a large cylindrical beryllium reflector that is subdivided into three concentric regions and encompasses the compact reactor core. Nuclear transmutations caused by neutron activation occur in the beryllium reflector regions, which leads to unwanted neutron absorbing and radiation emitting isotopes. During the past year, two topics related to the HFIR beryllium reflector were reviewed. The first topic included studying the neutron poison (helium-3 and lithium-6) buildup in the reflector regions and its affect on beginning-of-cycle reactivity. A new methodology was developed to predict the reactivity impact and estimated symmetrical critical control element positions as a function of outage time between cycles due to helium-3 buildup and was shown to be in better agreement with actual symmetrical critical control element position data than the current methodology. The second topic included studying the composition of the beryllium reflector regions at discharge as well as during decay to assess the viability of transporting, storing, and ultimately disposing the reflector regions currently stored in the spent fuel pool. The post-irradiation curie inventories were used to determine whether the reflector regions are discharged as transuranic waste or become transuranic waste during the decay period for disposal purposes and to determine the nuclear hazard category, which may affect the controls invoked for transportation and temporary storage. Two of the reflector regions were determined to be transuranic waste at discharge and the other region was determined to become transuranic waste in less than 2 years after being discharged due to the initial uranium content (0.0044 weight percent uranium). It was also concluded that all three of the reflector regions could be classified as nuclear hazard category 3 (potential for localized consequences only).

  2. Impact of HFIR LEU Conversion on Beryllium Reflector Degradation Factors

    SciTech Connect (OSTI)

    Ilas, Dan

    2013-10-01

    An assessment of the impact of low enriched uranium (LEU) conversion on the factors that may cause the degradation of the beryllium reflector is performed for the High Flux Isotope Reactor (HFIR). The computational methods, models, and tools, comparisons with previous work, along with the results obtained are documented and discussed in this report. The report documents the results for the gas and neutronic poison production, and the heating in the beryllium reflector for both the highly enriched uranium (HEU) and LEU HFIR configurations, and discusses the impact that the conversion to LEU may have on these quantities. A time-averaging procedure was developed to calculate the isotopic (gas and poisons) production in reflector. The sensitivity of this approach to different approximations is gauged and documented. The results show that the gas is produced in the beryllium reflector at a total rate of 0.304 g/cycle for the HEU configuration; this rate increases by ~12% for the LEU case. The total tritium production rate in reflector is 0.098 g/cycle for the HEU core and approximately 11% higher for the LEU core. A significant increase (up to ~25%) in the neutronic poisons production in the reflector during the operation cycles is observed for the LEU core, compared to the HEU case, for regions close to the core s horizontal midplane. The poisoning level of the reflector may increase by more than two orders of magnitude during long periods of downtime. The heating rate in the reflector is estimated to be approximately 20% lower for the LEU core than for the HEU core. The decrease is due to a significantly lower contribution of the heating produced by the gamma radiation for the LEU core. Both the isotopic (gas and neutronic poisons) production and the heating rates are spatially non-uniform throughout the beryllium reflector volume. The maximum values typically occur in the removable reflector and close to the midplane.

  3. Imaging with Spherically Bent Crystals or Reflectors (Technical Report) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Technical Report: Imaging with Spherically Bent Crystals or Reflectors Citation Details In-Document Search Title: Imaging with Spherically Bent Crystals or Reflectors This paper consists of two parts: Part I describes the working principle of a recently developed x-ray imaging crystal spectrometer, where the astigmatism of spherically bent crystals is being used with advantage to record spatially resolved spectra of highly charged ions for Doppler measurements of the

  4. Preliminary research on overmoded high-power millimeter-wave Cerenkov generator with dual-cavity reflector in low guiding magnetic field

    SciTech Connect (OSTI)

    Ye, Hu; Wu, Ping; Chen, Changhua; Ning, Hui; Tan, Weibing; Teng, Yan; Shi, Yanchao; Song, Zhimin; Cao, Yibing; Du, Zhaoyu

    2015-12-15

    This paper presents preliminary research on a V-band overmoded Cerenkov generator with dual-cavity reflector operating in a low guiding magnetic field. It is found that the fluctuation of the electron envelope in the low guiding magnetic field can be predicted using an equivalent coaxial model of a foilless diode, and a dual-cavity reflector based on the model matching method can provide strong reflection at the front end of the overmoded structures so that any microwave power that leaks into the diode region can be effectively suppressed. Numerical simulations indicate that the control of the beam envelope and the use of the dual-cavity reflector ease generator operation in the low guiding magnetic field. In the experimental research, the fluctuation of the annular electron beam with the outer radius of 7.5 mm measures approximately 0.7 mm, which is in good agreement with the theoretical results. The disturbance caused by power leaking from the overmoded slow wave structure is eliminated by the dual-cavity reflector. With accurate fabrication and assembly processes, an operating frequency of 61.6 GHz is attained by the fifth harmonic heterodyne method, and the output power is measured to be approximately 123 MW by the far-field measurement method at a diode voltage of 445 kV, a beam current of 4.45 kA, and under a guiding magnetic field of 1.45 T. The output mode is measured using an array of neon flash bulbs, and the pulse shortening phenomenon is both observed and analyzed.

  5. Contour mode resonators with acoustic reflectors

    DOE Patents [OSTI]

    Olsson, Roy H.; Fleming, James G.; Tuck, Melanie R.

    2008-06-10

    A microelectromechanical (MEM) resonator is disclosed which has a linear or ring-shaped acoustic resonator suspended above a substrate by an acoustic reflector. The acoustic resonator can be formed with a piezoelectric material (e.g. aluminum nitride, zinc oxide or PZT), or using an electrostatically-actuated material. The acoustic reflector (also termed an acoustic mirror) uses alternating sections of a relatively low acoustic impedance Z.sub.L material and a relatively high acoustic impedance Z.sub.H material to isolate the acoustic resonator from the substrate. The MEM resonator, which can be formed on a silicon substrate with conventional CMOS circuitry, has applications for forming oscillators, rf filters, and acoustic sensors.

  6. Reflector system for a lighting fixture

    DOE Patents [OSTI]

    Siminovitch, Michael J.; Page, Erik; Gould, Carl T.

    2001-01-01

    Disclosed herein is a reflector system for a lighting fixture having a illumination source surrounded by an envelope. The reflector system includes a first reflector surrounding the illumination source. The reflector system also includes a second reflector which is non-contiguous with the first reflector and which surrounds the illumination source. The illumination source creates light rays which are reflected by the first and second reflectors. The first reflector directs light rays toward the center line of the fixture. However, the reflected rays despite being so reflected do not substantially intersect the envelope. The reflected light rays from the second reflector being directed so that they diverge from the center line of the fixture avoiding intersection with the semi-transparent envelope.

  7. Reflector system for a lighting fixture

    DOE Patents [OSTI]

    Siminovitch, M.J.; Page, E.; Gould, C.T.

    1998-09-08

    Disclosed herein is a reflector system for a lighting fixture having a illumination source surrounded by an envelope. The reflector system includes a first reflector surrounding the illumination source. The reflector system also includes a second reflector which is non-contiguous with the first reflector and which surrounds the illumination source. The illumination source creates light rays which are reflected by the first and second reflectors. The first reflector directs light rays toward the center line of the fixture. However, the reflected rays despite being so reflected do not substantially intersect the envelope. The reflected light rays from the second reflector being directed so that they diverge from the center line of the fixture avoiding intersection with the semi-transparent envelope. 5 figs.

  8. Reflector system for a lighting fixture

    DOE Patents [OSTI]

    Siminovitch, Michael J.; Page, Erik; Gould, Carl T.

    1998-01-01

    Disclosed herein is a reflector system for a lighting fixture having a illumination source surrounded by an envelope. The reflector system includes a first reflector surrounding the illumination source. The reflector system also includes a second reflector which is non-contiguous with the first reflector and which surrounds the illumination source. The illumination source creates light rays which are reflected by the first and second reflectors. The first reflector directs light rays toward the center line of the fixture. However, the reflected rays despite being so reflected do not substantially intersect the envelope. The reflected light rays from the second reflector being directed so that they diverge from the center line of the fixture avoiding intersection with the semi-transparent envelope.

  9. Lamp bulb with integral reflector

    DOE Patents [OSTI]

    Levin, Izrail; Shanks, Bruce; Sumner, Thomas L.

    2001-01-01

    An improved electrodeless discharge lamp bulb includes an integral ceramic reflector as a portion of the bulb envelope. The bulb envelope further includes two pieces, a reflector portion or segment is cast quartz ceramic and a light transmissive portion is a clear fused silica. In one embodiment, the cast quartz ceramic segment includes heat sink fins or stubs providing an increased outside surface area to dissipate internal heat. In another embodiment, the quartz ceramic segment includes an outside surface fused to eliminate gas permeation by polishing.

  10. High-power green and blue electron-beam pumped surface-emitting lasers using dielectric and epitaxial distributed Bragg reflectors

    SciTech Connect (OSTI)

    Klein, T.; Klembt, S.; Kozlovsky, V. I.; Zheng, A.; Tiberi, M. D.; Kruse, C.

    2015-03-21

    ZnSe-based electron-beam pumped vertical-cavity surface-emitting lasers for the green (λ = 530 nm) and blue (λ = 462 nm) spectral region have been realized. Structures with and without epitaxial bottom distributed Bragg reflector have been fabricated and characterized. The samples consist of an active region containing 20 quantum wells with a cavity length varying between an optical thickness of 10 λ to 20 λ. The active material is ZnCdSSe in case of the green devices and ZnSe for the blue ones. Room temperature single mode lasing for structures with and without epitaxial bottom mirror with a maximum output power up to 5.9 W (green) and 3.3 W (blue) is achieved, respectively.

  11. Optical performance and durability of solar reflectors protected by an alumina coating

    SciTech Connect (OSTI)

    Kennedy, C.E.; Smilgys, R.V.; Kirkpatrick, D.A.; Ross, J.S.

    1996-07-01

    Solar thermal electric power systems use large solar reflectors to concentrate sunlight to generate electricity. The economic viability of these systems depends on developing a durable, low-cost reflector. The goals for such a reflector are specular reflectance above 90% for at least 10 years under outdoor service conditions and a large-volume manufacturing cost of less than $10.8/m{sup 2} ($1.00/ft{sup 2}). Currently, the best candidate materials for solar reflectors are silver-coated, low-iron glass and silvered polymer films. Polymer reflectors are lighter in weight, offer greater system design flexibility, and have the potential for lower cost than glass reflectors. A promising low-cost reflector consists of a silvered polymer protected by an optically transparent alumina coating. The coating is deposited by an ion-beam-assisted physical vapor deposition (IBAD) technique. Samples of this reflector have maintained high optical performance in accelerated testing at the National Renewable Energy Laboratory for more than 3000 hours. Solar reflectors produced using this technique may represent an opportunity to bring solar power generation to reality.

  12. Large-Scale All-Dielectric Metamaterial Perfect Reflectors

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

    Moitra, Parikshit; Slovick, Brian A.; li, Wei; Kravchencko, Ivan I.; Briggs, Dayrl P.; Krishnamurthy, S.; Valentine, Jason

    2015-05-08

    All-dielectric metamaterials offer a potential low-loss alternative to plasmonic metamaterials at optical frequencies. In this paper, we take advantage of the low absorption loss as well as the simple unit cell geometry to demonstrate large-scale (centimeter-sized) all-dielectric metamaterial perfect reflectors made from silicon cylinder resonators. These perfect reflectors, operating in the telecommunications band, were fabricated using self-assembly based nanosphere lithography. In spite of the disorder originating from the self-assembly process, the average reflectance of the metamaterial perfect reflectors is 99.7% at 1530 nm, surpassing the reflectance of metallic mirrors. Moreover, the spectral separation of the electric and magnetic resonances canmore » be chosen to achieve the required reflection bandwidth while maintaining a high tolerance to disorder. Finally, the scalability of this design could lead to new avenues of manipulating light for low-loss and large-area photonic applications.« less

  13. Lamp with a truncated reflector cup

    SciTech Connect (OSTI)

    Li, Ming; Allen, Steven C.; Bazydola, Sarah; Ghiu, Camil-Daniel

    2013-10-15

    A lamp assembly, and method for making same. The lamp assembly includes first and second truncated reflector cups. The lamp assembly also includes at least one base plate disposed between the first and second truncated reflector cups, and a light engine disposed on a top surface of the at least one base plate. The light engine is configured to emit light to be reflected by one of the first and second truncated reflector cups.

  14. Beam spoiling a reflector antenna with conducting shim. (Technical...

    Office of Scientific and Technical Information (OSTI)

    Beam spoiling a reflector antenna with conducting shim. Citation Details In-Document Search Title: Beam spoiling a reflector antenna with conducting shim. A horn-fed dish reflector...

  15. Method of making reflecting film reflector

    DOE Patents [OSTI]

    Cottingham, James G.

    1980-01-01

    A reflector of the reflecting film type is disclosed and which may be used in a heliostatic system for concentrating solar energy and comprising a reflecting film bonded to an appropriate rigid substrate in such a way that specularity of a very high order is achieved. A method of bonding the reflecting film to the substrate is also disclosed and comprises the steps of initially adhering the film to a smooth, clean flat rigid surface with a non-bonding liquid between the rigid surface and film, and then bonding the substrate and film. The non-bonding liquid has a molecular adhesion greater than any stresses due to handling or curing of the bonding agent which is applied between the film and the opposing surface of the rigid substrate.

  16. Electrophoretic deposited TiO2 pigment-based back reflectors for thin film solar cells

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

    Bills, Braden; Morris, Nathan; Dubey, Mukul; Wang, Qi; Fan, Qi Hua

    2015-01-16

    Highly reflective coatings with strong light scattering effect have many applications in optical components and optoelectronic devices. This paper reports titanium dioxide (TiO2) pigment-based reflectors that have 2.5 times higher broadband diffuse reflection than commercially produced aluminum or silver based reflectors and result in efficiency enhancements of a single-junction amorphous Si solar cell. Electrophoretic deposition is used to produce pigment-based back reflectors with high pigment density, controllable film thickness and site-specific deposition. Electrical conductivity of the pigment-based back reflectors is improved by creating electrical vias throughout the pigment-based back reflector by making holes using an electrical discharge / dielectric breakdownmore » approach followed by a second electrophoretic deposition of conductive nanoparticles into the holes. While previous studies have demonstrated the use of pigment-based back reflectors, for example white paint, on glass superstrate configured thin film Si solar cells, this work presents a scheme for producing pigment-based reflectors on complex shape and flexible substrates. Finally, mechanical durability and scalability are demonstrated on a continuous electrophoretic deposition roll-to-roll system which has flexible metal substrate capability of 4 inch wide and 300 feet long.« less

  17. Characterization of a 6 kW high-flux solar simulator with an array of xenon arc lamps capable of concentrations of nearly 5000 suns

    SciTech Connect (OSTI)

    Gill, Robert; Bush, Evan; Loutzenhiser, Peter; Haueter, Philipp

    2015-12-15

    A systematic methodology for characterizing a novel and newly fabricated high-flux solar simulator is presented. The high-flux solar simulator consists of seven xenon short-arc lamps mounted in truncated ellipsoidal reflectors. Characterization of spatial radiative heat flux distribution was performed using calorimetric measurements of heat flow coupled with CCD camera imaging of a Lambertian target mounted in the focal plane. The calorimetric measurements and images of the Lambertian target were obtained in two separate runs under identical conditions. Detailed modeling in the high-flux solar simulator was accomplished using Monte Carlo ray tracing to capture radiative heat transport. A least-squares regression model was used on the Monte Carlo radiative heat transfer analysis with the experimental data to account for manufacturing defects. The Monte Carlo ray tracing was calibrated by regressing modeled radiative heat flux as a function of specular error and electric power to radiation conversion onto measured radiative heat flux from experimental results. Specular error and electric power to radiation conversion efficiency were 5.92 ± 0.05 mrad and 0.537 ± 0.004, respectively. An average radiative heat flux with 95% errors bounds of 4880 ± 223 kW ⋅ m{sup −2} was measured over a 40 mm diameter with a cavity-type calorimeter with an apparent absorptivity of 0.994. The Monte Carlo ray-tracing resulted in an average radiative heat flux of 893.3 kW ⋅ m{sup −2} for a single lamp, comparable to the measured radiative heat fluxes with 95% error bounds of 892.5 ± 105.3 kW ⋅ m{sup −2} from calorimetry.

  18. Solar central receiver heliostat reflector assembly

    DOE Patents [OSTI]

    Horton, Richard H.; Zdeb, John J.

    1980-01-01

    A heliostat reflector assembly for a solar central receiver system comprises a light-weight, readily assemblable frame which supports a sheet of stretchable reflective material and includes mechanism for selectively applying tension to and positioning the sheet to stretch it to optical flatness. The frame is mounted on and supported by a pipe pedestal assembly that, in turn, is installed in the ground. The frame is controllably driven in a predetermined way by a light-weight drive system so as to be angularly adjustable in both elevation and azimuth to track the sun and efficiently continuously reflect the sun's rays to a focal zone, i.e. central receiver, which forms part of a solar energy utilization system, such as a solar energy fueled electrical power generation system. The frame may include a built-in system for testing for optical flatness of the reflector. The preferable geometric configuration of the reflector is octagonal; however, it may be other shapes, such as hexagonal, pentagonal or square. Several different embodiments of means for tensioning and positioning the reflector to achieve optical flatness are disclosed. The reflector assembly is based on the stretch frame concept which provides an extremely light-weight, simple, low-cost reflector assembly that may be driven for positioning and tracking by a light-weight, inexpensive drive system.

  19. Project Profile: Advanced Polymeric Reflector for CSP Applications |

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

    Department of Energy Polymeric Reflector for CSP Applications Project Profile: Advanced Polymeric Reflector for CSP Applications Abengoa logo Abengoa Solar, under the CSP R&D FOA, is developing and scaling up a previously demonstrated advanced solar reflector material for use in CSP applications. Approach A man holding a reflector panel above his head. This reflector material, last produced in 2003 under sponsorship by the National Renewable Energy Laboratory (NREL), is being

  20. Space Reflector Materials for Prometheus Application

    SciTech Connect (OSTI)

    J. Nash; V. Munne; LL Stimely

    2006-01-31

    The two materials studied in depth which appear to have the most promise in a Prometheus reflector application are beryllium (Be) and beryllium oxide (BeO). Three additional materials, magnesium oxide (MgO), alumina (Al{sub 2}O{sub 3}), and magnesium aluminate spinel (MgAl{sub 2}O{sub 4}) were also recently identified to be of potential interest, and may have promise in a Prometheus application as well, but are expected to be somewhat higher mass than either a Be or BeO based reflector. Literature review and analysis indicates that material properties for Be are largely known, but there are gaps in the properties of Be0 relative to the operating conditions for a Prometheus application. A detailed preconceptual design information document was issued providing material properties for both materials (Reference (a)). Beryllium oxide specimens were planned to be irradiated in the JOY0 Japanese test reactor to partially fill the material property gaps, but more testing in the High Flux Isotope Reactor (HFIR) test reactor at Oak Ridge National Laboratory (ORNL) was expected to be needed. A key issue identified for BeO was obtaining material for irradiation testing with an average grain size of {approx}5 micrometers, reminiscent of material for which prior irradiation test results were promising. Current commercially available material has an average grain size of {approx}10 micrometers. The literature indicated that improved irradiation performance could be expected (e.g., reduced irradiation-induced swelling) with the finer grain size material. Confirmation of these results would allow the use of historic irradiated materials test results from the literature, reducing the extent of required testing and therefore the cost of using this material. Environmental, safety and health (ES&H) concerns associated with manufacturing are significant but manageable for Be and BeO. Although particulate-generating operations (e.g., machining, grinding, etc.) involving Be

  1. Dual annular rotating "windowed" nuclear reflector reactor control system

    DOE Patents [OSTI]

    Jacox, Michael G.; Drexler, Robert L.; Hunt, Robert N. M.; Lake, James A.

    1994-01-01

    A nuclear reactor control system is provided in a nuclear reactor having a core operating in the fast neutron energy spectrum where criticality control is achieved by neutron leakage. The control system includes dual annular, rotatable reflector rings. There are two reflector rings: an inner reflector ring and an outer reflector ring. The reflectors are concentrically assembled, surround the reactor core, and each reflector ring includes a plurality of openings. The openings in each ring are capable of being aligned or non-aligned with each other. Independent driving means for each of the annular reflector rings is provided so that reactor criticality can be initiated and controlled by rotation of either reflector ring such that the extent of alignment of the openings in each ring controls the reflection of neutrons from the core.

  2. Electrophoretic deposited TiO2 pigment-based back reflectors for thin film solar cells

    SciTech Connect (OSTI)

    Bills, Braden; Morris, Nathan; Dubey, Mukul; Wang, Qi; Fan, Qi Hua

    2015-01-16

    Highly reflective coatings with strong light scattering effect have many applications in optical components and optoelectronic devices. This paper reports titanium dioxide (TiO2) pigment-based reflectors that have 2.5 times higher broadband diffuse reflection than commercially produced aluminum or silver based reflectors and result in efficiency enhancements of a single-junction amorphous Si solar cell. Electrophoretic deposition is used to produce pigment-based back reflectors with high pigment density, controllable film thickness and site-specific deposition. Electrical conductivity of the pigment-based back reflectors is improved by creating electrical vias throughout the pigment-based back reflector by making holes using an electrical discharge / dielectric breakdown approach followed by a second electrophoretic deposition of conductive nanoparticles into the holes. While previous studies have demonstrated the use of pigment-based back reflectors, for example white paint, on glass superstrate configured thin film Si solar cells, this work presents a scheme for producing pigment-based reflectors on complex shape and flexible substrates. Finally, mechanical durability and scalability are demonstrated on a continuous electrophoretic deposition roll-to-roll system which has flexible metal substrate capability of 4 inch wide and 300 feet long.

  3. Heavy reflector experiments in the IPEN/MB-01 reactor: Stainless steel, carbon steel and nickel

    SciTech Connect (OSTI)

    Santos, Adimir dos; Andrade e Silva, Graciete Simoes de; Jerez, Rogerio; Liambos Mura, Luis Felipe; Fuga, Rinaldo

    2013-05-06

    New experiments devoted to the measurements of physical parameters of a light water core surrounded by a heavy reflector were performed in the IPEN/MB-01 research reactor facility. These experiments comprise three sets of heavy reflector (SS-304, Carbon Steel, and Nickel) in a form of laminates around 3 mm thick. Each set was introduced individually in the west face of the core of the IPEN/MB-01 reactor. The aim here is to provide high quality experimental data for the interpretation and validation of the SS-304 heavy reflector calculation methods. The experiments of Carbon Steel, which is composed mainly of iron, and Nickel were performed to provide a consistent and an interpretative check for the SS-304 reflector experiment. The experimental results comprise critical control bank positions, temperatures and reactivities as a function of the number of the plates. Particularly to the case of Nickel, the experimental data are unique of its kind. The theoretical analysis was performed by MCNP-5 with the nuclear data library ENDF/B-VII.0. It was shown that this nuclear data library has a very good performance up to thirteen plates and overestimates the reactivity for higher number of plates independently of the type of the reflector.

  4. Ultraviolet reflector materials for solar detoxification of hazardous waste

    SciTech Connect (OSTI)

    Jorgensen, G.; Govindarajan, R.

    1991-07-01

    Organic waste detoxification requires cleavage of carbon bonds. Such reactions can be photo-driven by light that is energetic enough to disrupt such bonds. Alternately, light can be used to activate catalyst materials, which in turn can break organic bonds. In either case, photons with wavelengths less than 400 nm are required. Because the terrestrial solar resource below 400 nm is so small (roughly 3% of the available spectrum), highly efficient optical concentrators are needed that can withstand outdoor service conditions. In the past, optical elements for solar application have been designed to prevent ultraviolet (uv) radiation from reaching the reflective layer to avoid the potentially harmful effects of such light on the collector materials themselves. This effectively forfeits the uv part of the spectrum in return for some measure of protection against optical degradation. To optimize the cost/performance benefit of photochemical reaction systems, optical materials must be developed that are not only highly efficient but also inherently stable against the radiation they are designed to concentrate. The requirements of uv optical elements in terms of appropriate spectral bands and level of reflectance are established based upon the needs of photochemical applications. Relevant literature on uv reflector materials is reviewed which, along with discussions with industrial contacts, allows the establishment of a data base of currently available materials. Although a number of related technologies exist that require uv reflectors, to date little attention has been paid to achieving outdoor durability required for solar applications. 49 refs., 3 figs.

  5. Hybrid Back Surface Reflector GaInAsSb Thermophotovoltaic Devices

    SciTech Connect (OSTI)

    RK Huang; CA Wang; MK Connors; GW Turner; M Dashiell

    2004-05-11

    Back surface reflectors have the potential to improve thermophotovoltaic (TPV) device performance though the recirculation of infrared photons. The ''hybrid'' back-surface reflector (BSR) TPV cell approach allows one to construct BSRs for TPV devices using conventional, high efficiency, GaInAsSb-based TPV material. The design, fabrication, and measurements of hybrid BSR-TPV cells are described. The BSR was shown to provide a 4 mV improvement in open-circuit voltage under a constant shortcircuit current, which is comparable to the 5 mV improvement theoretically predicted. Larger improvements in open-circuit voltage are expected in the future with materials improvements.

  6. A Generalized Adjoint Approach for Quantifying Reflector Assembly...

    Office of Scientific and Technical Information (OSTI)

    However, there is currently no adjoint-based methodology to obtain uncertainties for ADFs along an interface between a fuel and reflector region. To accommodate leakage effects in ...

  7. Optical and Durability Evaluation for Silvered Polymeric Mirrors and Reflectors: Cooperative Research and Development Final Report, CRADA Number, CRD-08-316

    SciTech Connect (OSTI)

    Gray, M.

    2014-08-01

    3M is currently developing silvered polymeric mirror reflectors as low-cost replacements for glass mirrors in concentrating solar power (CSP) systems. This effort is focused on development of reflectors comprising both metallized polymeric mirror films based on improved versions of ECP-305+ or other durable mirror film concepts and appropriate mechanically robust substrates. The objectives for this project are to reduce the system capital and operating costs and to lower the levelized cost of energy for CSP installations. The development of mirror reflectors involves work on both full reflectors and mirror films with and without coatings. Mirror reflectors must meet rigid optical specifications in terms of radius of curvature, slope errors and specularity. Mirror films must demonstrate long-term durability and maintain high reflectivity. 3M would like to augment internal capabilities to validate product performance with methods and tools developed at NREL to address these areas.

  8. ZPR-3 Assembly 11 : A cylindrical sssembly of highly enriched uranium and depleted uranium with an average {sup 235}U enrichment of 12 atom % and a depleted uranium reflector.

    SciTech Connect (OSTI)

    Lell, R. M.; McKnight, R. D.; Tsiboulia, A.; Rozhikhin, Y.; National Security; Inst. of Physics and Power Engineering

    2010-09-30

    Over a period of 30 years, more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited for nuclear data validation and to form the basis for criticality safety benchmarks. A number of the Argonne ZPR/ZPPR critical assemblies have been evaluated as ICSBEP and IRPhEP benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. ZPR-3 Assembly 11 (ZPR-3/11) was designed as a fast reactor physics benchmark experiment with an average core {sup 235}U enrichment of approximately 12 at.% and a depleted uranium reflector. Approximately 79.7% of the total fissions in this assembly occur above 100 keV, approximately 20.3% occur below 100 keV, and essentially none below 0.625 eV - thus the classification as a 'fast' assembly. This assembly is Fast Reactor Benchmark No. 8 in the Cross Section Evaluation Working Group

  9. ARM: X-Band Scanning ARM Cloud Radar (W-SACR) Corner Reflector...

    Office of Scientific and Technical Information (OSTI)

    W-SACR) Corner Reflector Raster Scan Title: ARM: X-Band Scanning ARM Cloud Radar (W-SACR) Corner Reflector Raster Scan X-Band Scanning ARM Cloud Radar (W-SACR) Corner Reflector ...

  10. Modeling Mechanical Behavior of a Prismatic Replaceable Reflector Block

    SciTech Connect (OSTI)

    Robert Bratton

    2009-04-01

    This report outlines the development of finite element models used to determine temperature and stresses in a prismatic core reflector block. This initial analysis determines an appropriate temperature distribution in a prismatic reflector from limiting conditions in the adjacent fuel block based on simplifying assumptions.

  11. Photovoltaic generator with a spherical imaging lens for use with a paraboloidal solar reflector

    DOE Patents [OSTI]

    Angel, Roger P

    2013-01-08

    The invention is a generator for photovoltaic conversion of concentrated sunlight into electricity. A generator according to the invention incorporates a plurality of photovoltaic cells and is intended for operation near the focus of a large paraboloidal reflector pointed at the sun. Within the generator, the entering concentrated light is relayed by secondary optics to the cells arranged in a compact, concave array. The light is delivered to the cells at high concentration, consistent with high photovoltaic conversion efficiency and low cell cost per unit power output. Light enters the generator, preferably first through a sealing window, and passes through a field lens, preferably in the form of a full sphere or ball lens centered on the paraboloid focus. This lens forms a concentric, concave and wide-angle image of the primary reflector, where the intensity of the concentrated light is stabilized against changes in the position of concentrated light entering the generator. Receiving the stabilized light are flat photovoltaic cells made in different shapes and sizes and configured in a concave array corresponding to the concave image of a given primary reflector. Photovoltaic cells in a generator are also sized and interconnected so as to provide a single electrical output that remains high and stable, despite aberrations in the light delivered to the generator caused by, for example, mispointing or bending of the primary reflector. In some embodiments, the cells are set back from the image formed by the ball lens, and part of the light is reflected onto each cell small secondary reflectors in the form of mirrors set around its perimeter.

  12. ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Corner Reflector...

    Office of Scientific and Technical Information (OSTI)

    Title: ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Corner Reflector Calibration Ka-Band Scanning ARM Cloud Radar (KASACR) Corner Reflector Calibration Authors: Dan Nelson ; ...

  13. Monthly optimum inclination of glass cover and external reflector of a basin type solar still with internal and external reflector

    SciTech Connect (OSTI)

    Tanaka, Hiroshi

    2010-11-15

    In this report, we present a theoretical analysis of a basin type solar still with internal and external reflectors. The external reflector is a flat plate that extends from the back wall of the still, and can presumably be inclined forwards or backwards according to the month. We have theoretically predicted the daily amount of distillate produced by the still throughout the year, which varies according to the inclination angle of both the glass cover and the external reflector, at 30 N latitude. We found the optimum external reflector inclination for each month for a still with a glass cover inclination of 10-50 deg. The increase in the average daily amount of distillate throughout the year of a still with inclined external reflector with optimum inclination in addition to an internal reflector, compared to a conventional basin type still was predicted to be 29%, 43% or 67% when the glass cover inclination is 10 deg, 30 deg or 50 deg and the length of external reflector is half the still's length. (author)

  14. Promising Technology: Parabolic Aluminized Reflector Light-Emitting Diodes

    Broader source: Energy.gov [DOE]

    Parabolic aluminized reflectors, or PARs, are directional lamps typically used in recessed lighting. In contrast to CFLs, LEDs offer additional advantages including no warm up time, improved dimming and control capabilities, and for some products much greater efficacy ratings.

  15. Solar cell comprising a plasmonic back reflector and method therefor

    DOE Patents [OSTI]

    Ding, I-Kang; Zhu, Jia; Cui, Yi; McGehee, Michael David

    2014-11-25

    A method for forming a solar cell having a plasmonic back reflector is disclosed. The method includes the formation of a nanoimprinted surface on which a metal electrode is conformally disposed. The surface structure of the nanoimprinted surface gives rise to a two-dimensional pattern of nanometer-scale features in the metal electrode enabling these features to collectively form the plasmonic back reflector.

  16. Project Profile: Advanced Manufacture of Reflectors | Department of Energy

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

    Manufacture of Reflectors Project Profile: Advanced Manufacture of Reflectors University of Arizona logo -- This project is inactive -- The University of Arizona and its partners, under the 2012 Concentrating Solar Power (CSP) SunShot R&D funding opportunity announcement (FOA), are developing technology to improve the optical accuracy and reflectivity of the self-supporting glass mirrors used in CSP collector systems. Approach The research team is working to optimize and validate a novel

  17. Advanced ultraviolet-resistant silver mirrors for use in solar reflectors

    DOE Patents [OSTI]

    Jorgensen, Gary J.; Gee, Randy

    2009-11-03

    A silver mirror construction that maintains a high percentage of hemispherical reflectance throughout the UV and visible spectrum when used in solar reflectors, comprising:a) a pressure sensitive adhesive layer positioned beneath a silver overlay;b) a polymer film disposed on the silver overlay;c) an adhesive layer positioned on the polymer film; andd) a UV screening acrylic film disposed on the adhesive layer.

  18. Point-focus concentrator reflector assembly: Phase 1

    SciTech Connect (OSTI)

    Not Available

    1987-11-01

    A point-focus concentrator reflective assembly was developed in Phase I on contract 21-3695 under the direction of Sandia National Laboratories, Albuquerque. This concentrator is conventonal in presentation, yet innovative in detail. The development concentrated on structural efficiency and production design to achieve a high performance at minimum cost. The concentrator design achievs stiffness and strength through the integration of two structural elements. The optical element provides the reflective surface accuracy; a secondary support structure provides resistance to uniform and non-uniform load conditions. A retractable receiver strut, which moves the power conversion assembly out of focus in emergency power loss, was also incorporated. This same assembly provides maintanance access to the engine near ground level. A full-scale optical element was fabricated. Slope error was measured at 1 mrad. Concentrator performance was projected to be 88%, optical. This point-focus concentrator reflector assembly design provides low weight, low cost, and simplicity. Our analysis indicates these benefits are gained without impairing performance. 7 refs., 44 figs., 10 tabs.

  19. Method of manufacturing large dish reflectors for a solar concentrator apparatus

    DOE Patents [OSTI]

    Angel, Roger P; Olbert, Blain H

    2011-12-27

    A method of manufacturing monolithic glass reflectors for concentrating sunlight in a solar energy system is disclosed. The method of manufacturing allows large monolithic glass reflectors to be made from float glass in order to realize significant cost savings on the total system cost for a solar energy system. The method of manufacture includes steps of heating a sheet of float glass positioned over a concave mold until the sheet of glass sags and stretches to conform to the shape of the mold. The edges of the dish-shaped glass are rolled for structural stiffening around the periphery. The dish-shaped glass is then silvered to create a dish-shaped mirror that reflects solar radiation to a focus. The surface of the mold that contacts the float glass preferably has a grooved surface profile comprising a plurality of cusps and concave valleys. This grooved profile minimizes the contact area and marring of the specular glass surface, reduces parasitic heat transfer into the mold and increases mold lifetime. The disclosed method of manufacture is capable of high production rates sufficiently fast to accommodate the output of a conventional float glass production line so that monolithic glass reflectors can be produced as quickly as a float glass production can make sheets of float glass to be used in the process.

  20. Dual annular rotating [open quotes]windowed[close quotes] nuclear reflector reactor control system

    DOE Patents [OSTI]

    Jacox, M.G.; Drexler, R.L.; Hunt, R.N.M.; Lake, J.A.

    1994-03-29

    A nuclear reactor control system is provided in a nuclear reactor having a core operating in the fast neutron energy spectrum where criticality control is achieved by neutron leakage. The control system includes dual annular, rotatable reflector rings. There are two reflector rings: an inner reflector ring and an outer reflector ring. The reflectors are concentrically assembled, surround the reactor core, and each reflector ring includes a plurality of openings. The openings in each ring are capable of being aligned or non-aligned with each other. Independent driving means for each of the annular reflector rings is provided so that reactor criticality can be initiated and controlled by rotation of either reflector ring such that the extent of alignment of the openings in each ring controls the reflection of neutrons from the core. 4 figures.

  1. ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Corner Reflector...

    Office of Scientific and Technical Information (OSTI)

    Title: ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Corner Reflector Raster Scan Ka-Band Scanning ARM Cloud Radar (KASACR) Corner Reflector Raster Scan Authors: Dan Nelson ; ...

  2. Step-Stress Accelerated Degradation Testing for Solar Reflectors: Preprint

    SciTech Connect (OSTI)

    Jones, W.; Elmore, R.; Lee, J.; Kennedy, C.

    2011-09-01

    To meet the challenge to reduce the cost of electricity generated with concentrating solar power (CSP) new low-cost reflector materials are being developed including metalized polymer reflectors and must be tested and validated against appropriate failure mechanisms. We explore the application of testing methods and statistical inference techniques for quantifying estimates and improving lifetimes of concentrating solar power (CSP) reflectors associated with failure mechanisms initiated by exposure to the ultraviolet (UV) part of the solar spectrum. In general, a suite of durability and reliability tests are available for testing a variety of failure mechanisms where the results of a set are required to understand overall lifetime of a CSP reflector. We will focus on the use of the Ultra-Accelerated Weathering System (UAWS) as a testing device for assessing various degradation patterns attributable to accelerated UV exposure. Depending on number of samples, test conditions, degradation and failure patterns, test results may be used to derive insight into failure mechanisms, associated physical parameters, lifetimes and uncertainties. In the most complicated case warranting advanced planning and statistical inference, step-stress accelerated degradation (SSADT) methods may be applied.

  3. Long-Life Self-Renewing Solar Reflector Stack

    DOE Patents [OSTI]

    Butler, Barry Lynn

    1997-07-08

    A long-life solar reflector includes a solar collector substrate and a base layer bonded to a solar collector substrate. The first layer includes a first reflective layer and a first acrylic or transparent polymer layer covering the first reflective layer to prevent exposure of the first reflective layer. The reflector also includes at least one upper layer removably bonded to the first acrylic or transparent polymer layer of the base layer. The upper layer includes a second reflective layer and a second acrylic or transparent polymer layer covering the second reflective layer to prevent exposure of the second reflective layer. The upper layer may be removed from the base reflective layer to expose the base layer, thereby lengthening the useful life of the solar reflector. A method of manufacturing a solar reflector includes the steps of bonding a base layer to a solar collector substrate, wherein the base reflective layer includes a first reflective layer and a first transparent polymer or acrylic layer covering the first reflective layer; and removably bonding a first upper layer to the first transparent polymer or acrylic layer of the base layer. The first upper layer includes a second reflective layer and a second transparent polymer or acrylic layer covering the second reflective layer to prevent exposure of the second reflective layer.

  4. Lamp system with conditioned water coolant and diffuse reflector of polytetrafluorethylene(PTFE)

    DOE Patents [OSTI]

    Zapata, Luis E.; Hackel, Lloyd

    1999-01-01

    A lamp system with a very soft high-intensity output is provided over a large area by water cooling a long-arc lamp inside a diffuse reflector of polytetrafluorethylene (PTFE) and titanium dioxide (TiO.sub.2) white pigment. The water is kept clean and pure by a one micron particulate filter and an activated charcoal/ultraviolet irradiation system that circulates and de-ionizes and biologically sterilizes the coolant water at all times, even when the long-arc lamp is off.

  5. Remote examination of Fort St. Vrain HTGR fuel and reflector elements

    SciTech Connect (OSTI)

    McCord, F.; Saurwein, J.J.

    1984-01-01

    A robotic device developed at GA Technologies was used to perform remote metrological and visual examinations on 105 irradiated fuel and reflector elements removed from the High Temperature Gas Cooled Reactor (HTGR) core of the Fort St. Vrain (FSV) Nuclear Generating Station. All examinations were accomplished in a fraction of the time and at a fraction of the cost for manual methods. Theses examinations have been useful in the verification of core design codes, in monitoring the in-pile performance of graphite blocks, and in qualifying improved core materials.

  6. CX-000777: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Low-Cost, Highly Lambertian Reflector Composite for Improved LED (Light-Emitting Diode) Efficiency and LifetimeCX(s) Applied: B3.6Date: 02/10/2010Location(s): Newark, DelawareOffice(s): Energy Efficiency and Renewable Energy, National Energy Technology Laboratory

  7. Cube-corner reflectors with interference dielectric coating

    SciTech Connect (OSTI)

    Sokolov, A L; Murashkin, V V; Akent'ev, A S; Karaseva, E A

    2013-09-30

    The cube-corner reflectors (CCRs) with a special interference dielectric coating intended for ring retroreflector systems of space vehicles with uniaxial orientation are considered. The diffraction patterns of radiation reflected from the CCRs with different face coatings are studied. It is shown that the choice of the angle between the faces, the size and the coating of CCR faces allow essential variation in the diffraction pattern, thereby providing its optimisation for solving different navigation problems. (nanogradient dielectric coatings and metamaterials)

  8. Back reflectors based on buried Al{sub 2}O{sub 3} for enhancement of photon recycling in monolithic, on-substrate III-V solar cells

    SciTech Connect (OSTI)

    García, I.; Ward, J. S.; Steiner, M. A.; Geisz, J. F.; Kurtz, S. R.

    2014-09-29

    Photon management has been shown to be a fruitful way to boost the open circuit voltage and efficiency of high quality solar cells. Metal or low-index dielectric-based back reflectors can be used to confine the reemitted photons and enhance photon recycling. Gaining access to the back of the solar cell for placing these reflectors implies having to remove the substrate, with the associated added complexity to the solar cell manufacturing. In this work, we analyze the effectiveness of a single-layer reflector placed at the back of on-substrate solar cells, and assess the photon recycling improvement as a function of the refractive index of this layer. Al{sub 2}O{sub 3}-based reflectors, created by lateral oxidation of an AlAs layer, are identified as a feasible choice for on-substrate solar cells, which can produce a V{sub oc} increase of around 65% of the maximum increase attainable with an ideal reflector. The experimental results obtained using prototype GaAs cell structures show a greater than two-fold increase in the external radiative efficiency and a V{sub oc} increase of ∼2% (∼18 mV), consistent with theoretical calculations. For GaAs cells with higher internal luminescence, this V{sub oc} boost is calculated to be up to 4% relative (36 mV), which directly translates into at least 4% higher relative efficiency.

  9. Project Profile: Next-Generation Low-Cost Reflector | Department of Energy

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

    Low-Cost Reflector Project Profile: Next-Generation Low-Cost Reflector PPG logo PPG, under the Baseload CSP FOA, produced a durable first-surface mirror with improved optical performance and geometry design to reduce the unit cost of the reflector subcomponent in a concentrating solar power (CSP) application. Approach Illustration of a rectangle with four layers. PPG Industries created an ultra-large, front-surface glass mirror with an inorganic protective hardcoat. This approach worked toward

  10. Demonstration of a Single-Crystal Reflector-Filter for Enhancing Slow Neutron Beams

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

    Muhrer, Guenter; Schönfeldt, Troels; Iverson, Erik B.; Mocko, Michal; Baxter, David V.; Hügle, Thomas; Gallmeier, Franz X.; Klinkby, Esben

    2016-06-14

    The cold polycrystalline beryllium reflector-filter concept has been used to enhance the cold neutron emission of cryogenic hydrogen moderators, while suppressing the intermediate wavelength and fast neutron emission at the same time. While suppressing the fast neutron emission is often desired, the suppression of intermediate wavelength neutrons is often unwelcome. It has been hypothesized that replacing the polycrystalline reflector-filter concept with a single-crystal reflector-filter concept would overcome the suppression of intermediate wavelength neutrons and thereby extend the usability of the reflector-filter concept to shorter but still important wavelengths. In this paper we present the first experimental data on a single-crystalmore » reflector-filter and compare experimental results with hypothesized performance. We find that a single-crystal reflector-filter retains the long-wavelength benefit of the polycrystalline reflector-filter, without suffering the same loss of important intermediate wavelength neutrons. Ultimately, this finding extends the applicability of the reflector-filter concept to intermediate wavelengths, and furthermore indicates that the reflector-filter benefits arise from its interaction with fast (background) neutrons, not with intermediate wavelength neutrons of potential interest in many types of neutron scattering.« less

  11. Optical device with low electrical and thermal resistance bragg reflectors

    DOE Patents [OSTI]

    Lear, Kevin L.

    1996-01-01

    A compound-semiconductor optical device and method. The optical device is provided with one or more asymmetrically-graded heterojunctions between compound semiconductor layers for forming a distributed Bragg reflector mirror having an improved electrical and thermal resistance. Efficient light-emitting devices such as light-emitting diodes, resonant-cavity light-emitting diodes, and vertical-cavity surface-emitting lasers may be formed according to the present invention, which may be applied to the formation of resonant-cavity photodetectors.

  12. Optical device with low electrical and thermal resistance Bragg reflectors

    DOE Patents [OSTI]

    Lear, K.L.

    1996-10-22

    A compound-semiconductor optical device and method are disclosed. The optical device is provided with one or more asymmetrically-graded heterojunctions between compound semiconductor layers for forming a distributed Bragg reflector mirror having an improved electrical and thermal resistance. Efficient light-emitting devices such as light-emitting diodes, resonant-cavity light-emitting diodes, and vertical-cavity surface-emitting lasers may be formed according to the present invention, which may be applied to the formation of resonant-cavity photodetectors. 16 figs.

  13. Reflector and Shield Material Properties for Project Prometheus

    SciTech Connect (OSTI)

    J. Nash

    2005-11-02

    This letter provides updated reflector and shield preliminary material property information to support reactor design efforts. The information provided herein supersedes the applicable portions of Revision 1 to the Space Power Program Preliminary Reactor Design Basis (Reference (a)). This letter partially answers the request in Reference (b) to provide unirradiated and irradiated material properties for beryllium, beryllium oxide, isotopically enriched boron carbide ({sup 11}B{sub 4}C) and lithium hydride. With the exception of {sup 11}B{sub 4}C, the information is provided in Attachments 1 and 2. At the time of issuance of this document, {sup 11}B{sub 4}C had not been studied.

  14. All-reflective optical target illumination system with high numerical aperture

    DOE Patents [OSTI]

    Sigler, Robert D.

    1978-01-01

    An all-reflective optical system for providing illumination of a target focal region at high numerical aperture from a pair of co-axially, confluent collimated light beams. A target cavity is defined by a pair of opposed inner ellipsoidal reflectors having respective first focal points within a target region and second focal points at a vertex opening in the opposing reflector. Outwardly of each inner reflector is the opposed combination of a spherical reflector, and an outer generally ellipsoidal reflector having an aberrated first focal point coincident with the focus of the opposing spherical reflector and a second focal point coincident with the second focal point of the opposing inner ellipsoidal reflector through a vertex opening in the spherical reflector. The confluent collimated beams are incident through vertex openings in the outer ellipsoidal reflectors onto respective opposing spherical reflectors. Each beam is reflected by the associated spherical reflector onto the opposing outer ellipsoidal reflector and focused thereby onto the opposing inner ellipsoidal reflector, and then onto the target region.

  15. Reflector for efficient coupling of a laser beam to air or other fluids

    DOE Patents [OSTI]

    Kare, J.T.

    1992-10-06

    A reflector array is disclosed herein that provides a controlled region or regions of plasma breakdowns from a laser beam produced at a remotely-based laser source. The plasma may be applied to produce thrust to propel a spacecraft, or to diagnose a laser beam, or to produce shock waves. The spacecraft propulsion system comprises a reflector array attached to the vehicle. The reflector array comprises a plurality of reflectors spaced apart on a reflective surface, with each reflector acting as an independent focusing mirror. The reflectors are spaced closely together to form a continuous or partially-continuous surface. The reflector array may be formed from a sheet of reflective material, such as copper or aluminum. In operation, a beam of electromagnetic energy, such as a laser beam, is directed at the reflectors which focus the reflected electromagnetic energy at a plurality of regions off the surface. The energy concentrated in the focal region causes a breakdown of the air or other fluid in the focal region, creating a plasma. Electromagnetic energy is absorbed in the plasma and it grows in volume, compressing and heating the adjacent fluid thereby providing thrust. Laser pulses may be applied repetitively. After each such thrust pulse, fresh air can be introduced next to the surface either laterally, or through a perforated surface. If air or some other gas or vapor is supplied, for example from a tank carried on board a vehicle, this invention may also be used to provide thrust in a vacuum environment. 10 figs.

  16. Reflector for efficient coupling of a laser beam to air or other fluids

    DOE Patents [OSTI]

    Kare, Jordin T.

    1992-01-01

    A reflector array is disclosed herein that provides a controlled region or regions of plasma breakdowns from a laser beam produced at a remotely-based laser source. The plasma may be applied to produce thrust to propel a spacecraft, or to diagnose a laser beam, or to produce shockwaves. The spacecraft propulsion system comprises a reflector array attached to the vehicle. The reflector array comprises a plurality of reflectors spaced apart on a reflective surface, with each reflector acting as an independent focusing mirror. The reflectors are spaced closely together to form a continuous or partially-continuous surface. The reflector array may be formed from a sheet of reflective material, such as copper or aluminum. In operation, a beam of electromagnetic energy, such as a laser beam, is directed at the reflectors which focus the reflected electromagnetic energy at a plurality of regions off the surface. The energy concentrated in the focal region causes a breakdown of the air or other fluid in the focal region, creating a plasma. Electromagnetic energy is absorbed in the plasma and it grows in volume, compressing and heating the adjacent fluid thereby providing thrust. Laser pulses may be applied repetitively. After each such thrust pulse, fresh air can be introduced next to the surface either laterally, or through a perforated surface. If air or some other gas or vapor is supplied, for example from a tank carried on board a vehicle, this invention may also be used to provide thrust in a vacuum environment.

  17. Deep ultraviolet distributed Bragg reflectors based on graded composition AlGaN alloys

    SciTech Connect (OSTI)

    Brummer, Gordie; Nothern, Denis; Nikiforov, A. Yu.; Moustakas, T. D.

    2015-06-01

    Distributed Bragg reflectors (DBRs) with peak reflectivity at approximately 280 nm, based on compositionally graded Al{sub x}Ga{sub 1−x}N alloys, were grown on 6H-SiC substrates by plasma-assisted molecular beam epitaxy. DBRs with square, sinusoidal, triangular, and sawtooth composition profiles were designed with the transfer matrix method. The crystal structure of these DBRs was studied with high-resolution x-ray diffraction of the (1{sup ¯}015) reciprocal lattice point. The periodicity of the DBR profiles was confirmed with cross-sectional Z-contrast scanning transmission electron microscopy. The peak reflectance of these DBRs with 15.5 periods varies from 77% to 56% with corresponding full width at half maximum of 17–14 nm. Coupled mode analysis was used to explain the dependence of the reflectivity characteristics on the profile of the graded composition.

  18. Nondestructive examination of 51 fuel and reflector elements from Fort St. Vrain Core Segment 1

    SciTech Connect (OSTI)

    Miller, C.M.; Saurwein, J.J.

    1980-12-01

    Fifty-one fuel and reflector elements irradiated in core segment 1 of the Fort St. Vrain High-Temperature Gas-Cooled Reactor (HTGR) were inspected dimensionally and visually in the Hot Service Facility at Fort St. Vrain in July 1979. Time- and volume-averaged graphite temperatures for the examined fuel elements ranged from approx. 400/sup 0/ to 750/sup 0/C. Fast neutron fluences varied from approx. 0.3 x 10/sup 25/ n/m/sup 2/ to 1.0 x 10/sup 25/ n/m/sup 2/ (E > 29 fJ)/sub HTGR/. Nearly all of the examined elements shrank in both axial and radial dimensions. The measured data were compared with strain and bow predictions obtained from SURVEY/STRESS, a computer code that employs viscoelastic beam theory to calculate stresses and deformations in HTGR fuel elements.

  19. Nondestructive examination of 54 fuel and reflector elements from Fort St. Vrain core segment 2

    SciTech Connect (OSTI)

    Saurwein, J.J.

    1982-10-01

    Fifty-four fuel and reflector elements irradiated in core segment 2 of the Fort St. Vrain high-temperature gas-cooled reactor (HTGR) were nondestructively examined. The time- and volume-averaged graphite irradiation temperatures for the elements ranged from approx. 350/sup 0/ to 750/sup 0/C. The element-averaged fast neutron fluences ranged from approx. 0.2 to 1.6 x 10/sup 25/ n/m/sup 2/ (E > 29 fJ)/sub HTGR/. The elements, except for two fuel elements in which single localizeed cracks developed during irradiation, were in excellent condition. No evidence was observed of significant graphite oxidation or mechanical interaction beween elements. The cracks in the two elements did not affect their performance or handling. These elements were, otherwise, in excellent condition. Nearly all elements shrank in both the axial and radial directions, but the dimensional changes were relatively small.

  20. Distributed bragg reflector using AIGaN/GaN

    DOE Patents [OSTI]

    Waldrip, Karen E.; Lee, Stephen R.; Han, Jung

    2004-08-10

    A supported distributed Bragg reflector or superlattice structure formed from a substrate, a nucleation layer deposited on the substrate, and an interlayer deposited on the nucleation layer, followed by deposition of (Al,Ga,B)N layers or multiple pairs of (Al,Ga,B)N/(Al,Ga,B)N layers, where the interlayer is a material selected from AlN, Al.sub.x Ga.sub.1-x N, and AlBN with a thickness of approximately 20 to 1000 angstroms. The interlayer functions to reduce or eliminate the initial tensile growth stress, thereby reducing cracking in the structure. Multiple interlayers utilized in an AlGaN/GaN DBR structure can eliminate cracking and produce a structure with a reflectivity value greater than 0.99.

  1. AlGaAsSb/GaSb Distributed Bragg Reflectors Grown by Organometallic Vapor Phase Epitaxy

    SciTech Connect (OSTI)

    C.A. Wang; C.J. Vineis; D.R. Calawa

    2002-02-13

    The first AlGaAsSb/GaSb quarter-wave distributed Bragg reflectors grown by metallic vapor phase epitaxy are reported. The peak reflectance is 96% for a 10-period structure.

  2. Photodetector with absorbing region having resonant periodic absorption between reflectors

    DOE Patents [OSTI]

    Bryan, R.P.; Olbright, G.R.; Brennan, T.M.; Tsao, J.Y.

    1995-02-14

    A photodetector is disclosed that is responsive to a wavelength or wavelengths of interest which have heretofore been unrealized. The photodetector includes a resonant cavity structure bounded by first and second reflectors, the resonant cavity structure being resonant at the wavelength or wavelengths of interest for containing a plurality of standing waves therein. The photodetector further includes a radiation absorbing region disposed within the resonant cavity structure, the radiation absorbing region including a plurality of radiation absorbing layers spaced apart from one another by a distance substantially equal to a distance between antinodes of adjacent ones of the standing waves. Each of radiation absorbing layers is spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced. The radiation absorbing layers may be either bulk layers or quantum wells includes a plurality of layers, each of which is comprised of a strained layer of InGaAs. Individual ones of the InGaAs layers are spaced apart from one another by a GaAs barrier layer. 11 figs.

  3. Photodetector with absorbing region having resonant periodic absorption between reflectors

    DOE Patents [OSTI]

    Bryan, Robert P.; Olbright, Gregory R.; Brennan, Thomas M.; Tsao, Jeffrey Y.

    1995-02-14

    A photodetector that is responsive to a wavelength or wavelengths of interest which have heretofore been unrealized. The photodetector includes a resonant cavity structure bounded by first and second reflectors, the resonant cavity structure being resonant at the wavelength or wavelengths of interest for containing a plurality of standing waves therein. The photodetector further includes a radiation absorbing region disposed within the resonant cavity structure, the radiation absorbing region including a plurality of radiation absorbing layers spaced apart from one another by a distance substantially equal to a distance between antinodes of adjacent ones of the standing waves. Each of radiation absorbing layers is spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced. The radiation absorbing layers may be either bulk layers or quantum wells includes a plurality of layers, each of which is comprised of a strained layer of InGaAs. Individual ones of the InGaAs layers are spaced apart from one another by a GaAs barrier layer.

  4. Project Profile: Low-Cost Self-Cleaning Reflector Coatings for CSP

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

    Collectors | Department of Energy Cost Self-Cleaning Reflector Coatings for CSP Collectors Project Profile: Low-Cost Self-Cleaning Reflector Coatings for CSP Collectors Oak Ridge National Laboratory logo -- This project is inactive -- The Oak Ridge National Laboratory (ORNL), under the National Laboratory R&D competitive funding opportunity, is developing self-cleaning, optically transparent coatings that can be applied to the surfaces of heliostats and collector mirrors in concentrating

  5. Midtemperature solar systems test facility predictions for thermal performance of the Acurex solar collector with FEK 244 reflector surface

    SciTech Connect (OSTI)

    Harrison, T.D.

    1981-01-01

    Thermal performance predictions are presented for the Acurex solar collector, with FEK 244 reflector surface, for three output temperatures at five cities in the United States.

  6. Correlated-intensity velocimeter for arbitrary reflector for laser-produced plasma experiments

    SciTech Connect (OSTI)

    Wang Zhehui; Luo Shengnian; Barnes, Cris W.; Briggs, Matthew E.; Paisley, Dennis L.; Paul, Stephen F.

    2006-10-15

    A laser-based technique, called correlated-intensity velocimeter for arbitrary reflector (CIVAR), is described for velocity measurement of reflecting surfaces in real time. Velocity versus time is an important measurement in laser-produced high-energy density plasma experiments because the motion of the surface depends on both the equation of the state of the surface material and laser-produced plasma. The physics and working principle of CIVAR are the same as those of a previous concept that resolves Doppler shift of plasma light emission using a pair of narrow passband interference filters. One unique feature of CIVAR is that a reflected laser beam is used instead of plasma emission. Therefore, CIVAR is applicable to both emitting and nonemitting reflecting surfaces. Other advantages of CIVAR include its simplicity, lower cost, and unambiguous data analysis that can be fully automated. The design of a single-point CIVAR is described in detail with emphasis on laser wavelength selection and signal-to-noise ratio. The single-point CIVAR system can be expanded into a multiple-point system straightforwardly. It is possible to use CIVAR concept to construct a two-dimensional imaging system for a nonuniform velocity field of a large reflecting surface; such a velocity imaging system may have applications beyond laser-produced plasma experiments, for example, in shock compression of condensed matter.

  7. Long-range, full-duplex, modulated-reflector cell phone for voice/data transmission

    DOE Patents [OSTI]

    Neagley, Daniel L.; Briles, Scott D.; Coates, Don M.; Freund, Samuel M.

    2002-01-01

    A long-range communications apparatus utilizing modulated-reflector technology is described. The apparatus includes an energy-transmitting base station and remote units that do not emit radiation in order to communicate with the base station since modulated-reflector technology is used whereby information is attached to an RF carrier wave originating from the base station which is reflected by the remote unit back to the base station. Since the remote unit does not emit radiation, only a low-power power source is required for its operation. Information from the base station is transmitted to the remote unit using a transmitter and receiver, respectively. The range of such a communications system is determined by the properties of a modulated-reflector half-duplex link.

  8. Wafer-Bonded Internal Back-Surface Reflectors for Enhanced TPV Performance

    SciTech Connect (OSTI)

    C.A. Wang; P.G. Murphy; P.W. O'Brien; D.A. Shiau; A.C. Anderson; Z.L. Liau; D.M. Depoy; G. Nichols

    2002-08-12

    This paper discusses recent efforts to realize GaInAsSb/GaSb TPV cells with an internal back-surface reflector (BSR). The cells are fabricated by wafer bonding the GaInAsSb/GaSb device layers to GaAs substrates with a dielectric/Au reflector, and subsequently removing the GaSb substrate. The internal BSR enhances optical absorption within the device while the dielectric layer provides electrical isolation. This approach is compatible with monolithic integration of series-connected TPV cells and can mitigate the requirements of filters used for front-surface spectral control.

  9. Performance improvements of symmetry-breaking reflector structures in nonimaging devices

    DOE Patents [OSTI]

    Winston, Roland

    2004-01-13

    A structure and method for providing a broken symmetry reflector structure for a solar concentrator device. The component of the optical direction vector along the symmetry axis is conserved for all rays propagated through a translationally symmetric optical device. This quantity, referred to as the translational skew invariant, is conserved in rotationally symmetric optical systems. Performance limits for translationally symmetric nonimaging optical devices are derived from the distributions of the translational skew invariant for the optical source and for the target to which flux is to be transferred. A numerically optimized non-tracking solar concentrator utilizing symmetry-breaking reflector structures can overcome the performance limits associated with translational symmetry.

  10. Reflector Technology Development and System Design for Concentrating Solar Power Technologies

    SciTech Connect (OSTI)

    Adam Schaut Philip Smith

    2011-12-30

    Alcoa began this program in March of 2008 with the goal of developing and validating an advanced CSP trough design to lower the levelized cost of energy (LCOE) as compared to existing glass based, space-frame trough technology. In addition to showing a pathway to a significant LCOE reduction, Alcoa also desired to create US jobs to support the emerging CSP industry. Alcoa's objective during Phase I: Concept Feasibility was to provide the DOE with a design approach that demonstrates significant overall system cost savings without sacrificing performance. Phase I consisted of two major tasks; reflector surface development and system concept development. Two specific reflective surface technologies were investigated, silver metallized lamination, and thin film deposition both applied on an aluminum substrate. Alcoa prepared samples; performed test validation internally; and provided samples to the NREL for full-spectrum reflectivity measurements. The final objective was to report reflectivity at t = 0 and the latest durability results as of the completion of Phase 1. The target criteria for reflectance and durability were as follows: (1) initial (t = 0), hemispherical reflectance >93%, (2) initial spectral reflectance >90% for 25-mrad reading and >87% for 7-mrad reading, and (3) predicted 20 year durability of less than 5% optical performance drop. While the results of the reflective development activities were promising, Alcoa was unable to down-select on a reflective technology that met the target criteria. Given the progress and potential of both silver film and thin film technologies, Alcoa continued reflector surface development activities in Phase II. The Phase I concept development activities began with acquiring baseline CSP system information from both CSP Services and the DOE. This information was used as the basis to develop conceptual designs through ideation sessions. The concepts were evaluated based on estimated cost and high-level structural

  11. Advanced Reflector and Absorber Materials (Fact Sheet), Thermal...

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

    coating developed in the laboratory was recently commercialized, based on its excellent prop- erties of high absorption, low emittance, and resistance to oxidation. Contact Cheryl...

  12. Solar receiver heliostat reflector having a linear drive and position information system

    DOE Patents [OSTI]

    Horton, Richard H.

    1980-01-01

    A heliostat for a solar receiver system comprises an improved drive and control system for the heliostat reflector assembly. The heliostat reflector assembly is controllably driven in a predetermined way by a light-weight drive system so as to be angularly adjustable in both elevation and azimuth to track the sun and efficiently continuously reflect the sun's rays to a focal zone, i.e., heat receiver, which forms part of a solar energy utilization system, such as a solar energy fueled electrical power generation system. The improved drive system includes linear stepping motors which comprise low weight, low cost, electronic pulse driven components. One embodiment comprises linear stepping motors controlled by a programmed, electronic microprocessor. Another embodiment comprises a tape driven system controlled by a position control magnetic tape.

  13. Development and Testing of Abrasion Resistant Hard Coats For Polymer Film Reflectors: Preprint

    SciTech Connect (OSTI)

    Jorgensen, G.; Gee, R.; DiGrazia, M.

    2010-10-01

    Reflective polymer film technology can significantly reduce the cost of solar reflectors and installed Concentrated Solar Power (CSP) plants by both reduced material cost and lower weight. One challenge of polymer reflectors in the CSP environment pertains to contact cleaning methods typically used with glass mirrors. Such contact cleaning methods can scratch the surface of polymer reflectors and thereby reduce specular reflectance. ReflecTech, Inc. (a subsidiary of SkyFuel, Inc.) and the National Renewable Energy Laboratory (NREL) initiated a cooperative research and development agreement (CRADA) to devise and develop an abrasion resistant coating (ARC) suitable for deposition onto polymer based mirror film. A number of candidate ARC products were identified as candidate formulations. Industrial collaborators prepared samples having their ARCs deposited onto ReflecTech Mirror Film pre-laminated to aluminum sheet substrates. Samples were provided for evaluation and subjected to baseline (unweathered) and accelerated exposure conditions and subsequently characterized for abrasion resistance and adhesion. An advanced ARC product has been identified that exhibits outstanding initial abrasion resistance and adhesion to ReflecTech Mirror Film. These properties were also retained after exposure to the various accelerated stress conditions. This material has been successfully manufactured as a 1.5 m wide roll-to-roll construction in a production environment.

  14. Multijunction GaInP/GaInAs/Ge solar cells with Bragg reflectors

    SciTech Connect (OSTI)

    Emelyanov, V. M. Kalyuzhniy, N. A.; Mintairov, S. A.; Shvarts, M. Z.; Lantratov, V. M.

    2010-12-15

    Effect of subcell parameters on the efficiency of GaInP/Ga(In)As/Ge tandem solar cells irradiated with 1-MeV electrons at fluences of up to 3 x 10{sup 15} cm{sup -2} has been theoretically studied. The optimal thicknesses of GaInP and GaInAs subcells, which provide the best photocurrent matching at various irradiation doses in solar cells with and without built-in Bragg reflectors, were determined. The dependences of the photoconverter efficiency on the fluence of 1-MeV electrons and on the time of residence in the geostationary orbit were calculated for structures optimized to the beginning and end of their service lives. It is shown that the optimization of the subcell heterostructures for a rated irradiation dose and the introduction of Bragg reflectors into the structure provide a 5% overall increase in efficiency for solar cells operating in the orbit compared with unoptimized cells having no Bragg reflector.

  15. Chemical Effect of Dry and Wet Cleaning of the Ru Protective Layer of the Extreme ultraviolet (EUV) Lithography Reflector

    SciTech Connect (OSTI)

    Belau, Leonid; Park, Jeong Y.; Liang, Ted; Seo, Hyungtak; Somorjai, Gabor A.

    2009-04-10

    The authors report the chemical influence of cleaning of the Ru capping layer on the extreme ultraviolet (EUV) reflector surface. The cleaning of EUV reflector to remove the contamination particles has two requirements: to prevent corrosion and etching of the reflector surface and to maintain the reflectivity functionality of the reflector after the corrosive cleaning processes. Two main approaches for EUV reflector cleaning, wet chemical treatments [sulfuric acid and hydrogen peroxide mixture (SPM), ozonated water, and ozonated hydrogen peroxide] and dry cleaning (oxygen plasma and UV/ozone treatment), were tested. The changes in surface morphology and roughness were characterized using scanning electron microscopy and atomic force microscopy, while the surface etching and change of oxidation states were probed with x-ray photoelectron spectroscopy. Significant surface oxidation of the Ru capping layer was observed after oxygen plasma and UV/ozone treatment, while the oxidation is unnoticeable after SPM treatment. Based on these surface studies, the authors found that SPM treatment exhibits the minimal corrosive interactions with Ru capping layer. They address the molecular mechanism of corrosive gas and liquid-phase chemical interaction with the surface of Ru capping layer on the EUV reflector.

  16. Development of Advanced Polymeric Reflector for CSP Applications - Final Report

    SciTech Connect (OSTI)

    Treglio, Richard, T; Boyle, Keith, A; Henderson, Hildie

    2013-03-28

    This project attempted to deposit extremely thick and dense protective barrier onto a mirror film stack with a PET substrate. The target thickness was very high for thin film products; particularly since large areas and long production lengths of film are needed to make the final product economic. The technical investigations in this project centered on maintaining a quality barrier (i.e. dense film) while evaporating alumina with a high deposition rate onto a low cost PET substrate. The project found that the proposed configuration, particularly direct ion bombardment, provides too narrow a solution space to effectively and economically produce the ASRM attempted. The initial project goals were met when depositing on a limited width and at a modest rate. However, expanding to wide deposition at aggressive deposition rates did not produce consistent film quality. Economic viability drives the process to maximize deposition rate. The current system configuration has a limiting upper rate threshold that does not appear economically viable. For future work, alternate approaches seem needed to address the challenges encountered in the scale-up phase of this project.

  17. Midtemperature Solar Systems Test Facility predictions for thermal performance of the Suntec solar collector with heat-formed glass reflector surface

    SciTech Connect (OSTI)

    Harrison, T.D.

    1980-11-01

    Thermal performance predictions are presented for the Suntec solar collector, with heat-formed glass reflector surface, for three output temperatures at five cities in the United States.

  18. DOE Publishes Final Rule for the Request for Exclusion of 100 Watt R20 Short Incandescent Reflector Lamps from Energy Conservation Standards

    Broader source: Energy.gov [DOE]

    The Department of Energy has published a final rule regarding the request for exclusion of 100 Watt R20 short incandescent reflector lamps from energy conservation standards.

  19. Presentation of the MERC work-flow for the computation of a 2D radial reflector in a PWR

    SciTech Connect (OSTI)

    Clerc, T.; Hebert, A.; Leroyer, H.; Argaud, J. P.; Poncot, A.; Bouriquet, B.

    2013-07-01

    This paper presents a work-flow for computing an equivalent 2D radial reflector in a pressurized water reactor (PWR) core, in adequacy with a reference power distribution, computed with the method of characteristics (MOC) of the lattice code APOLLO2. The Multi-modelling Equivalent Reflector Computation (MERC) work-flow is a coherent association of the lattice code APOLLO2 and the core code COCAGNE, structured around the ADAO (Assimilation de Donnees et Aide a l'Optimisation) module of the SALOME platform, based on the data assimilation theory. This study leads to the computation of equivalent few-groups reflectors, that can be spatially heterogeneous, which have been compared to those obtained with the OPTEX similar methodology developed with the core code DONJON, as a first validation step. Subsequently, the MERC work-flow is used to compute the most accurate reflector in consistency with all the R and D choices made at Electricite de France (EDF) for the core modelling, in terms of number of energy groups and simplified transport solvers. We observe important reductions of the power discrepancies distribution over the core when using equivalent reflectors obtained with the MERC work-flow. (authors)

  20. See-through amorphous silicon solar cells with selectively transparent and conducting photonic crystal back reflectors for building integrated photovoltaics

    SciTech Connect (OSTI)

    Yang, Yang; OBrien, Paul G.; Materials Chemistry Research Group, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 ; Ozin, Geoffrey A. E-mail: kherani@ecf.utoronto.ca; Kherani, Nazir P. E-mail: kherani@ecf.utoronto.ca

    2013-11-25

    Thin semi-transparent hydrogenated amorphous silicon (a-Si:H) solar cells with selectively transparent and conducting photonic crystal (STCPC) back-reflectors are demonstrated. Short circuit current density of a 135?nm thick a-Si:H cell with a given STCPC back-reflector is enhanced by as much as 23% in comparison to a reference cell with an ITO film functioning as its rear contact. Concurrently, solar irradiance of 295?W/m{sup 2} and illuminance of 3480 lux are transmitted through the cell with a given STCPC back reflector under AM1.5 Global tilt illumination, indicating its utility as a source of space heating and lighting, respectively, in building integrated photovoltaic applications.

  1. Application of ITO/Al reflectors for increasing the efficiency of single-crystal silicon solar cells

    SciTech Connect (OSTI)

    Kopach, V. R.; Kirichenko, M. V. Khrypunov, G. S.; Zaitsev, R. V.

    2010-06-15

    It is shown that an increase in the efficiency and manufacturability of single-junction single-crystal silicon photoelectric converters of solar energy requires the use of a back-surface reflector based on conductive transparent indium-tin oxide (ITO) 0.25-2 {mu}m thick. To increase the efficiency and reduce the sensitivity to the angle of light incidence on the photoreceiving surface of multijunction photoelectric converters with vertical diode cells based on single-crystal silicon, ITO/Al reflectors with an ITO layer >1 {mu}m thick along vertical boundaries of diode cells should be fabricated. The experimental study of multijunction photoelectric converters with ITO/Al reflectors at diode cell boundaries shows the necessity of modernizing the used technology of ITO layers to achieve their theoretically calculated thickness.

  2. Analyses of the reflector tank, cold source, and beam tube cooling for ANS reactor

    SciTech Connect (OSTI)

    Marland, S.

    1992-07-01

    This report describes my work as an intern with Martin Marietta Energy Systems, Inc., in the summer of 1991. I was assigned to the Reactor Technology Engineering Department, working on the Advanced Neutron Source (ANS). My first project was to select and analyze sealing systems for the top of the diverter/reflector tank. This involved investigating various metal seals and calculating the forces necessary to maintain an adequate seal. The force calculations led to an analysis of several bolt patterns and lockring concepts that could be used to maintain a seal on the vessel. Another project involved some pressure vessel stress calculations and the calculation of the center of gravity for the cold source assembly. I also completed some sketches of possible cooling channel patterns for the inner vessel of the cold source. In addition, I worked on some thermal design analyses for the reflector tank and beam tubes, including heat transfer calculations and assisting in Patran and Pthermal analyses. To supplement the ANS work, I worked on other projects. I completed some stress/deflection analyses on several different beams. These analyses were done with the aid of CAASE, a beam-analysis software package. An additional project involved bending analysis on a carbon removal system. This study was done to find the deflection of a complex-shaped beam when loaded with a full waste can.

  3. MHD compressor---expander conversion system integrated with GCR inside a deployable reflector

    SciTech Connect (OSTI)

    Tuninetti, G. . Research Div.); Botta, E.; Criscuolo, C.; Riscossa, P. . Nuclear Div.); Giammanco, F. . Dipt. di Fisica); Rosa-Clot, M. . Dipt. di Fisica)

    1989-04-20

    This work originates from the proposal MHD Compressor-Expander Conversion System Integrated with a GCR Inside a Deployable Reflector''. The proposal concerned an innovative concept of nuclear, closed-cycle MHD converter for power generation on space-based systems in the multi-megawatt range. The basic element of this converter is the Power Conversion Unit (PCU) consisting of a gas core reactor directly coupled to an MHD expansion channel. Integrated with the PCU, a deployable reflector provides reactivity control. The working fluid could be either uranium hexafluoride or a mixture of uranium hexafluoride and helium, added to enhance the heat transfer properties. The original Statement of Work, which concerned the whole conversion system, was subsequently redirected and focused on the basic mechanisms of neutronics, reactivity control, ionization and electrical conductivity in the PCU. Furthermore, the study was required to be inherently generic such that the study was required to be inherently generic such that the analysis an results can be applied to various nuclear reactor and/or MHD channel designs''.

  4. New Method to Characterize Degradation of First Surface Aluminum Reflectors: Preprint

    SciTech Connect (OSTI)

    Sutter, F.; Heller, P.; Meyen, S.; Pitz-Paal, R.; Kennedy, C.; Fernandez-Garcia, A.; Schmucker, M.

    2010-10-01

    This paper reports the development of a new optical instrument capable of characterizing the aging process of enhanced first surface aluminum reflectors for concentrating solar power (CSP) application. Samples were exposed outdoors at different sites and in accelerated exposure tests. All samples exposed outdoors showed localized corrosion spots. Degradation originated from points of damage in the protective coating, but propagated underneath the protective coating. The degraded samples were analyzed with a microscope and with a newly designed space-resolved specular reflectometer (SR)2 that is capable of optically detecting and characterizing the corrosion spots. The device measures the specular reflectance at three acceptance angles and the wavelengths with spatial resolution using a digital camera's CMOS sensor. It can be used to measure the corrosion growth rate during outdoor and accelerated exposure tests. These results will allow a correlation between the degraded mirror surface and its specular reflectance.

  5. Midtemperature solar systems test facility predictions for thermal performance based on test data. Polisolar Model POL solar collector with glass reflector surface

    SciTech Connect (OSTI)

    Harrison, T.D.

    1981-05-01

    Thermal performance predictions based on test data are presented for the Polisolar Model POL solar collector, with glass reflector surfaces, for three output temperatures at five cities in the United States.

  6. Midtemperature solar systems test facility predictions for thermal performance based on test data. Toltec two-axis tracking solar collector with 3M acrylic polyester film reflector surface

    SciTech Connect (OSTI)

    Harrison, T.D.

    1981-06-01

    Thermal performance predictions based on test data are presented for the Toltec solar collector, with acrylic film reflector surface, for three output temperatures at five cities in the United States.

  7. Midtemperature Solar Systems Test Facility predictions for thermal performance of the Solar Kinetics T-700 solar collector with FEK 244 reflector surface

    SciTech Connect (OSTI)

    Harrison, T.D.

    1980-11-01

    Thermal performance predictions are presented for the Solar Kinetics T-700 solar collector, with FEK 244 reflector surface, for three output temperatures at five cities in the United States.

  8. Non-astigmatic imaging with matched pairs of spherically bent reflectors

    DOE Patents [OSTI]

    Bitter, Manfred Ludwig; Hill, Kenneth Wayne; Scott, Steven Douglas; Feder, Russell; Ko, Jinseok; Rice, John E.; Ince-Cushman, Alexander Charles; Jones, Frank

    2012-07-10

    Arrangements for the point-to-point imaging of a broad spectrum of electromagnetic radiation and ultrasound at large angles of incidence employ matched pairs of spherically bent reflectors to eliminate astigmatic imaging errors. Matched pairs of spherically bent crystals or spherically bent multi-layers are used for X-rays and EUV radiation; and matched pairs of spherically bent mirrors that are appropriate for the type of radiation are used with microwaves, infrared and visible light, or ultrasound. The arrangements encompass the two cases, where the Bragg angle--the complement to the angle of incidence in optics--is between 45.degree. and 90.degree. on both crystals/mirrors or between 0.degree. and 45.degree. on the first crystal/mirror and between 45.degree. and 90.degree. on the second crystal/mirror, where the angles of convergence and divergence are equal. For x-rays and EUV radiation, also the Bragg condition is satisfied on both spherically bent crystals/multi-layers.

  9. Observation of Significant Quantum Efficiency Enhancement from a Polarized Photocathode with Distributed Brag Reflector

    SciTech Connect (OSTI)

    Zhang, Shukui; Poelker, Matthew; Stutzman, Marcy L.; Chen, Yiqiao; Moy, Aaron

    2015-09-01

    Polarized photocathodes with higher Quantum efficiency (QE) would help to reduce the technological challenge associated with producing polarized beams at milliampere levels, because less laser light would be required, which simplifies photocathode cooling requirements. And for a given amount of available laser power, higher QE would extend the photogun operating lifetime. The distributed Bragg reflector (DBR) concept was proposed to enhance the QE of strained-superlattice photocathodes by increasing the absorption of the incident photons using a Fabry-Perot cavity formed between the front surface of the photocathode and the substrate that includes a DBR, without compromising electron polarization. Here we present recent results showing QE enhancement of a GaAs/GaAsP strained-superlattice photocathode made with a DBR structure. Typically, a GaAs/GaAsP strained-superlattice photocathode without DBR provides a QE of 1%, at a laser wavelength corresponding to peak polarization. In comparison, the GaAs/GaAsP strained-superlattice photocathodes with DBR exhibited an enhancement of over 2 when the incident laser wavelength was tuned to meet the resonant condition for the Fabry-Perot resonator.

  10. High intensity, pulsed thermal neutron source

    DOE Patents [OSTI]

    Carpenter, J.M.

    1973-12-11

    This invention relates to a high intensity, pulsed thermal neutron source comprising a neutron-producing source which emits pulses of fast neutrons, a moderator block adjacent to the last neutron source, a reflector block which encases the fast neutron source and the moderator block and has a thermal neutron exit port extending therethrough from the moderator block, and a neutron energy- dependent decoupling reflector liner covering the interior surfaces of the thermal neutron exit port and surrounding all surfaces of the moderator block except the surface viewed by the thermal neutron exit port. (Official Gazette)

  11. Effect of non-uniform slow wave structure in a relativistic backward wave oscillator with a resonant reflector

    SciTech Connect (OSTI)

    Chen, Changhua; Xiao, Renzhen; Sun, Jun; Song, Zhimin; Huo, Shaofei; Bai, Xianchen; Shi, Yanchao; Liu, Guozhi

    2013-11-15

    This paper provides a fresh insight into the effect of non-uniform slow wave structure (SWS) used in a relativistic backward wave oscillator (RBWO) with a resonant reflector. Compared with the uniform SWS, the reflection coefficient of the non-uniform SWS is higher, leading to a lower modulating electric field in the resonant reflector and a larger distance to maximize the modulation current. Moreover, for both types of RBWOs, stronger standing-wave field takes place at the rear part of the SWS. In addition, besides Cerenkov effects, the energy conversion process in the RBWO strongly depends on transit time effects. Thus, the matching condition between the distributions of harmonic current and standing wave field provides a profound influence on the beam-wave interaction. In the non-uniform RBWO, the region with a stronger standing wave field corresponds to a higher fundamental harmonic current distribution. Particle-in-cell simulations show that with a diode voltage of 1.02 MV and beam current of 13.2 kA, a microwave power of 4 GW has been obtained, compared to that of 3 GW in the uniform RBWO.

  12. Analyses of the reflector tank, cold source, and beam tube cooling for ANS reactor. [Advanced Neutron Source (ANS)

    SciTech Connect (OSTI)

    Marland, S. )

    1992-07-01

    This report describes my work as an intern with Martin Marietta Energy Systems, Inc., in the summer of 1991. I was assigned to the Reactor Technology Engineering Department, working on the Advanced Neutron Source (ANS). My first project was to select and analyze sealing systems for the top of the diverter/reflector tank. This involved investigating various metal seals and calculating the forces necessary to maintain an adequate seal. The force calculations led to an analysis of several bolt patterns and lockring concepts that could be used to maintain a seal on the vessel. Another project involved some pressure vessel stress calculations and the calculation of the center of gravity for the cold source assembly. I also completed some sketches of possible cooling channel patterns for the inner vessel of the cold source. In addition, I worked on some thermal design analyses for the reflector tank and beam tubes, including heat transfer calculations and assisting in Patran and Pthermal analyses. To supplement the ANS work, I worked on other projects. I completed some stress/deflection analyses on several different beams. These analyses were done with the aid of CAASE, a beam-analysis software package. An additional project involved bending analysis on a carbon removal system. This study was done to find the deflection of a complex-shaped beam when loaded with a full waste can.

  13. Midtemperature Solar Systems Test Facility predictions for thermal performance based on test data: Custom Engineering trough with glass reflector surface and Sandia-designed receivers

    SciTech Connect (OSTI)

    Harrison, T.D.

    1981-05-01

    Thermal performance predictions based on test data are presented for the Custom Engineering trough and Sandia-designed receivers, with glass reflector surface, for three output temperatures at five cities in the United States. Two experimental receivers were tested, one with an antireflective coating on the glass envelope around the receiver tube and one without the antireflective coating.

  14. 2014-04-11 Issuance: Energy Conservation Standards for General Service Fluorescent Lamps and Incandescent Reflector Lamps; Notice of Proposed Rulemaking

    Broader source: Energy.gov [DOE]

    This document is a pre-publication Federal Register notice of proposed rulemaking regarding energy conservation standards for general service fluorescent lamps and incandescent reflectors lamps, as issued by the Assistant Secretary for Energy Efficiency and Renewable Energy on April 11, 2014.

  15. Electromagnetic modeling of the energy distribution of a metallic cylindrical parabolic reflector covered with a magnetized plasma layer

    SciTech Connect (OSTI)

    Niknam, A. R. Khajehmirzaei, M. R.; Davoudi-Rahaghi, B.; Rahmani, Z.; Jazi, B.; Abdoli-Arani, A.

    2014-07-15

    The energy distribution along the focal axis of a long metallic cylindrical parabolic reflector with a plasma layer on its surface in the presence of an external magnetic field is investigated. The effects of some physical parameters, such as the plasma frequency, the wave frequency and the thickness of plasma layer on the energy distribution and the reflected and transmitted electromagnetic fields, are simulated. These investigations for both S- and P-polarizations have been done separately. It is found that the maximum value of the reflected intensity increases by increasing the incident wave frequency and by decreasing the plasma layer thickness and the plasma frequency for both polarizations. Furthermore, the results show that the increase of the magnetic field strength can cause an increase in the reflected intensity for S-polarization and a slight decrease for P-polarization.

  16. Metamorphic distributed Bragg reflectors for the 1440–1600 nm spectral range: Epitaxy, formation, and regrowth of mesa structures

    SciTech Connect (OSTI)

    Egorov, A. Yu. Karachinsky, L. Ya.; Novikov, I. I.; Babichev, A. V.; Berezovskaya, T. N.; Nevedomskiy, V. N.

    2015-10-15

    It is shown that metamorphic In{sub 0.3}Ga{sub 0.7}As/In{sub 0.3}Al{sub 0.7}As distributed Bragg reflectors (DBRs) with a reflection band at 1440–1600 nm and a reflectance of no less than 0.999 can be fabricated by molecular beam epitaxy (MBE) on a GaAs substrate. It is demonstrated that mesa structures formed from metamorphic DBRs on a GaAs substrate can be regrown by MBE and microcavities can be locally formed in two separate epitaxial processes. The results obtained can find wide application in the fabrication of vertical-cavity surface-emitting lasers (VCSELs) with a buried tunnel junction.

  17. Optimal design of one-dimensional photonic crystal back reflectors for thin-film silicon solar cells

    SciTech Connect (OSTI)

    Chen, Peizhuan; Hou, Guofu Zhang, Jianjun Zhang, Xiaodan; Zhao, Ying

    2014-08-14

    For thin-film silicon solar cells (TFSC), a one-dimensional photonic crystal (1D PC) is a good back reflector (BR) because it increases the total internal reflection at the back surface. We used the plane-wave expansion method and the finite difference time domain (FDTD) algorithm to simulate and analyze the photonic bandgap (PBG), the reflection and the absorption properties of a 1D PC and to further explore the optimal 1D PC design for use in hydrogenated amorphous silicon (a-Si:H) solar cells. With identified refractive index contrast and period thickness, we found that the PBG and the reflection of a 1D PC are strongly influenced by the contrast in bilayer thickness. Additionally, light coupled to the top three periods of the 1D PC and was absorbed if one of the bilayers was absorptive. By decreasing the thickness contrast of the absorptive layer relative to the non-absorptive layer, an average reflectivity of 96.7% was achieved for a 1D PC alternatively stacked with a-Si:H and SiO{sub 2} in five periods. This reflectivity was superior to a distributed Bragg reflector (DBR) structure with 93.5% and an Ag film with 93.4%. n-i-p a-Si:H solar cells with an optimal 1D PC-based BR offer a higher short-circuit current density than those with a DBR-based BR or an AZO/Ag-based BR. These results provide new design rules for photonic structures in TFSC.

  18. WhiteOptics' Low-Cost Reflector Composite Boosts LED Fixture Efficiency

    Broader source: Energy.gov [DOE]

    With the help of DOE funding, WhiteOptics has developed a composite coating that can be used to improve efficiency in backlit, indirect, and cavity-mixing LED luminaire designs by maximizing light reflection and output. The highly diffuse coating, which is based on a novel high-reflectance particle technology, allows for uniform distribution of light without exaggerating the point-source nature of the LEDs, and is intended to offer an overall system cost-improving solution for LED optics.

  19. Midtemperature Solar Systems Test Facility predictions for thermal performance based on test data. Alpha Solarco Model 104 solar collector with 0. 125-inch Schott low-iron glass reflector surface

    SciTech Connect (OSTI)

    Harrison, T.D.

    1981-04-01

    Thermal performance predictions based on test data are presented for the Alpha Solarco Model 104 solar collector, with 0.125-inch Schott low-iron glass reflector surface, for three output temperatures at five cities in the United States.

  20. Fiber optic sensor employing successively destroyed coupled points or reflectors for detecting shock wave speed and damage location

    DOE Patents [OSTI]

    Weiss, Jonathan D.

    1995-01-01

    A shock velocity and damage location sensor providing a means of measuring shock speed and damage location. The sensor consists of a long series of time-of-arrival "points" constructed with fiber optics. The fiber optic sensor apparatus measures shock velocity as the fiber sensor is progressively crushed as a shock wave proceeds in a direction along the fiber. The light received by a receiving means changes as time-of-arrival points are destroyed as the sensor is disturbed by the shock. The sensor may comprise a transmitting fiber bent into a series of loops and fused to a receiving fiber at various places, time-of-arrival points, along the receiving fibers length. At the "points" of contact, where a portion of the light leaves the transmitting fiber and enters the receiving fiber, the loops would be required to allow the light to travel backwards through the receiving fiber toward a receiving means. The sensor may also comprise a single optical fiber wherein the time-of-arrival points are comprised of reflection planes distributed along the fibers length. In this configuration, as the shock front proceeds along the fiber it destroys one reflector after another. The output received by a receiving means from this sensor may be a series of downward steps produced as the shock wave destroys one time-of-arrival point after another, or a nonsequential pattern of steps in the event time-of-arrival points are destroyed at any point along the sensor.

  1. Fiber optic sensor employing successively destroyed coupled points or reflectors for detecting shock wave speed and damage location

    DOE Patents [OSTI]

    Weiss, J.D.

    1995-08-29

    A shock velocity and damage location sensor providing a means of measuring shock speed and damage location is disclosed. The sensor consists of a long series of time-of-arrival ``points`` constructed with fiber optics. The fiber optic sensor apparatus measures shock velocity as the fiber sensor is progressively crushed as a shock wave proceeds in a direction along the fiber. The light received by a receiving means changes as time-of-arrival points are destroyed as the sensor is disturbed by the shock. The sensor may comprise a transmitting fiber bent into a series of loops and fused to a receiving fiber at various places, time-of-arrival points, along the receiving fibers length. At the ``points`` of contact, where a portion of the light leaves the transmitting fiber and enters the receiving fiber, the loops would be required to allow the light to travel backwards through the receiving fiber toward a receiving means. The sensor may also comprise a single optical fiber wherein the time-of-arrival points are comprised of reflection planes distributed along the fibers length. In this configuration, as the shock front proceeds along the fiber it destroys one reflector after another. The output received by a receiving means from this sensor may be a series of downward steps produced as the shock wave destroys one time-of-arrival point after another, or a nonsequential pattern of steps in the event time-of-arrival points are destroyed at any point along the sensor. 6 figs.

  2. Performance enhancement of thin film silicon solar cells based on distributed Bragg reflector and diffraction grating

    SciTech Connect (OSTI)

    Dubey, R. S.; Saravanan, S.; Kalainathan, S.

    2014-12-15

    The influence of various designing parameters were investigated and explored for high performance solar cells. Single layer grating based solar cell of 50 μm thickness gives maximum efficiency up to 24 % whereas same efficiency is achieved with the use of three bilayers grating based solar cell of 30 μm thickness. Remarkably, bilayer grating based solar cell design not only gives broadband absorption but also enhancement in efficiency with reduced cell thickness requirement. This absorption enhancement is attributed to the high reflection and diffraction from DBR and grating respectively. The obtained short-circuit current were 29.6, 32.9, 34.6 and 36.05 mA/cm{sup 2} of 5, 10, 20 and 30 μm cell thicknesses respectively. These presented designing efforts would be helpful to design and realize new generation of solar cells.

  3. Benchmark Evaluation of Uranium Metal Annuli and Cylinders with Beryllium Reflectors

    SciTech Connect (OSTI)

    John D. Bess

    2010-06-01

    An extensive series of delayed critical experiments were performed at the Oak Ridge Critical Experiments Facility using enriched uranium metal during the 1960s and 1970s in support of criticality safety operations at the Y-12 Plant. These experiments were designed to evaluate the storage, casting, and handling limits of the Y-12 Plant and to provide data for the verification of cross sections and calculation methods utilized in nuclear criticality safety applications. Many of these experiments have already been evaluated and included in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) Handbook: unreflected (HEU-MET-FAST-051), graphite-reflected (HEU-MET-FAST-071), and polyethylene-reflected (HEU-MET-FAST-076). Three of the experiments consisted of highly-enriched uranium (HEU, ~93.2% 235U) metal parts reflected by beryllium metal discs. The first evaluated experiment was constructed from a stack of 7-in.-diameter, 4-1/8-in.-high stack of HEU discs top-reflected by a 7-in.-diameter, 5-9/16-in.-high stack of beryllium discs. The other two experiments were formed from stacks of concentric HEU metal annular rings surrounding a 7-in.diameter beryllium core. The nominal outer diameters were 13 and 15 in. with a nominal stack height of 5 and 4 in., respectively. These experiments have been evaluated for inclusion in the ICSBEP Handbook.

  4. ORALLOY (93.2 235U) METAL CYLINDER WITH BERYLLIUM TOP REFLECTOR

    SciTech Connect (OSTI)

    John D. Bess; Leland M. Montierth; Raymond Reed; John T. Mihalczo

    2010-09-01

    A variety of critical experiments were constructed of enriched uranium metal during the 1960s and 1970s at the Oak Ridge Critical Experiments Facility (ORCEF) in support of criticality safety operations at the Y-12 Plant. The purposes of these experiments included the evaluation of storage, casting, and handling limits for the Y-12 Plant and providing data for verification of calculation methods and cross-sections for nuclear criticality safety applications. These included solid cylinders of various diameters, annuli of various inner and outer diameters, two and three interacting cylinders of various diameters, and graphite and polyethylene reflected cylinders and annuli. Of the hundreds of delayed critical experiments, one experiment was comprised of a stack of approximately 7-inch-diameter metal discs. The bottom of the stack consisted of uranium with an approximate height of 4-1/8 inches. The top of the stack consisted of beryllium with an approximate height of 5-9/16 inches. This experiment was performed on August 20, 1963 by J. T. Mihalczo and R. G. Taylor (Ref. 1) with accompanying logbook. Both detailed and simplified model specifications are provided in this evaluation. This fast-spectra experiment was determined to represent an acceptable benchmark. The calculated eigenvalues for both the detailed and simple models are within approximately 0.5% of the benchmark values, but significantly greater than 3s from the benchmark value because the uncertainty in the benchmark is very small: 0.0002 (1s). There is significant variability between results using different neutron cross section libraries, the greatest being a ?keff of ~0.65% . Unreflected and unmoderated experiments with the same highly enriched uranium metal parts were performed at the Oak Ridge Critical Experiments Facility in the 1960s and are evaluated in HEU MET FAST 051. Thin graphite reflected (2 inches or less) experiments also using the same highly enriched uranium metal parts are evaluated in

  5. All-reflective optical target illumination system with high numerical aperture

    DOE Patents [OSTI]

    Thomas, Carlton E.; Sigler, Robert D.; Hoeger, John G.

    1979-01-01

    An all-reflective optical system for providing illumination of a target focal region at high numerical aperture from a pair of confluent collimated light beams. The collimated beams are each incident upon an associated concave eccentric pupil paraboloidal reflective surface, and thereby each focused through an opening in an associated outer ellipsoidal reflective surface onto a plane reflector. Each beam is reflected by its associated plane reflector onto the opposing concave surface of the outer ellipsoids to be focused through an opening in the plane surface onto an opposing inner concave ellipsoidal reflective surface, and thence onto the target region.

  6. Magneto-exciton-polariton condensation in a sub-wavelength high contrast grating based vertical microcavity

    SciTech Connect (OSTI)

    Fischer, J.; Brodbeck, S.; Worschech, L.; Kamp, M.; Schneider, C.; Hfling, S.; Zhang, B.; Wang, Z.; Deng, H.

    2014-03-03

    We comparably investigate the diamagnetic shift of an uncoupled quantum well exciton with a microcavity exciton-polariton condensate on the same device. The sample is composed of multiple GaAs quantum wells in an AlAs microcavity, surrounded by a Bragg reflector and a sub-wavelength high contrast grating reflector. Our study introduces an independent and easily applicable technique, namely, the measurement of the condensate diamagnetic shift, which directly probes matter contributions in polariton condensates and hence discriminates it from a conventional photon laser.

  7. Research on stable, high-efficiency amorphous silicon multijunction modules

    SciTech Connect (OSTI)

    Guha, S. )

    1991-12-01

    This report describes research to improve the understanding of amorphous silicon alloys and other relevant non-semiconductor materials for use in high-efficiency, large-area multijunction modules. The research produced an average subcell initial efficiency of 8.8% over a 1-ft{sup 2} area using same-band-gap, dual-junction cells deposited over a ZnO/AlSi back reflector. An initial efficiency of 9.6% was achieved using a ZnO/Ag back reflector over smaller substrates. A sputtering machine will be built to deposit a ZnO/Ag back reflector over a 1-ft{sup 2} area so that a higher efficiency can also be obtained on larger substrates. Calculations have been performed to optimize the grid pattern, bus bars, and cell interconnects on modules. With our present state of technology, we expect a difference of about 6% between the aperture-area and active-area efficiencies of modules. Preliminary experiments show a difference of about 8%. We can now predict the performance of single-junction cells after long-term light exposure at 50{degree}C by exposing cells to short-term intense light at different temperatures. We find that single-junction cells deposited on a ZnO/Ag back reflector show the highest stabilized efficiency when the thickness of the intrinsic layers is about 2000 {angstrom}. 8 refs.

  8. Extreme ultraviolet reflector

    DOE Patents [OSTI]

    Newnam, Brian E.

    1990-01-01

    A multi-faceted mirror forms a retroreflector for a resonator loop in a free electron laser (FEL) operating in the XUV (.lambda.=10-100 nm). The number of facets is determined by the angle-of-incidence needed to obtain total external reflectance (TER) from the facet surface and the angle through which the FEL beam is to be turned. Angles-of-incidence greater than the angle for TER may be used to increase the area of the beam incident on the surface and reduce energy absorption density. Suitable surface films having TER in the 10-100 nm range may be formed from a variety of materials, including Al, single-crystal Si, Ag, and Rh. One of the facets is formed as an off-axis conic section to collimate the output beam with minimum astigmatism.

  9. Ultraviolet GaN photodetectors on Si via oxide buffer heterostructures with integrated short period oxide-based distributed Bragg reflectors and leakage suppressing metal-oxide-semiconductor contacts

    SciTech Connect (OSTI)

    Szyszka, A. E-mail: adam.szyszka@pwr.wroc.pl; Haeberlen, M.; Storck, P.; Thapa, S. B.; Schroeder, T.

    2014-08-28

    Based on a novel double step oxide buffer heterostructure approach for GaN integration on Si, we present an optimized Metal-Semiconductor-Metal (MSM)-based Ultraviolet (UV) GaN photodetector system with integrated short-period (oxide/Si) Distributed Bragg Reflector (DBR) and leakage suppressing Metal-Oxide-Semiconductor (MOS) electrode contacts. In terms of structural properties, it is demonstrated by in-situ reflection high energy electron diffraction and transmission electron microscopy-energy dispersive x-ray studies that the DBR heterostructure layers grow with high thickness homogeneity and sharp interface structures sufficient for UV applications; only minor Si diffusion into the Y{sub 2}O{sub 3} films is detected under the applied thermal growth budget. As revealed by comparative high resolution x-ray diffraction studies on GaN/oxide buffer/Si systems with and without DBR systems, the final GaN layer structure quality is not significantly influenced by the growth of the integrated DBR heterostructure. In terms of optoelectronic properties, it is demonstrated thatwith respect to the basic GaN/oxide/Si system without DBRthe insertion of (a) the DBR heterostructures and (b) dark current suppressing MOS contacts enhances the photoresponsivity below the GaN band-gap related UV cut-off energy by almost up to two orders of magnitude. Given the in-situ oxide passivation capability of grown GaN surfaces and the one order of magnitude lower number of superlattice layers in case of higher refractive index contrast (oxide/Si) systems with respect to classical III-N DBR superlattices, virtual GaN substrates on Si via functional oxide buffer systems are thus a promising robust approach for future GaN-based UV detector technologies.

  10. Verification of the MCU precision code and ROSFOND neutron data in application to the calculations of criticality of fast reactors with highly enriched uranium

    SciTech Connect (OSTI)

    Alekseev, N. I.; Kalugin, M. A.; Kulakov, A. S.; Novosel’tsev, A. P.; Sergeev, G. S.; Shkarovskiy, D. A.; Yudkevich, M. S.

    2014-12-15

    Calculation of 335 critical assemblies (benchmark experiments) with the core of highly enriched uranium and reflectors of various materials is performed. The statistical analysis of the results shows that, for all 16 materials studied, the absolute value of the most probable deviation of the calculated value of K{sub eff} from the experimental one does not exceed 0.005.

  11. Project Profile: High-Temperature Thermal Array for Next-Generation Solar

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

    Thermal Power Production | Department of Energy Thermal Array for Next-Generation Solar Thermal Power Production Project Profile: High-Temperature Thermal Array for Next-Generation Solar Thermal Power Production Los Alamos National Laboratory logo The Los Alamos National Laboratory (LANL), under the National Laboratory R&D competitive funding opportunity, is developing a megawatt-scale heat pipe-based technology designed to bridge the heliostat reflector field and the power cycle by

  12. High power water load for microwave and millimeter-wave radio frequency sources

    DOE Patents [OSTI]

    Ives, R. Lawrence; Mizuhara, Yosuke M.; Schumacher, Richard V.; Pendleton, Rand P.

    1999-01-01

    A high power water load for microwave and millimeter wave radio frequency sources has a front wall including an input port for the application of RF power, a cylindrical dissipation cavity lined with a dissipating material having a thickness which varies with depth, and a rear wall including a rotating reflector for the reflection of wave energy inside the cylindrical cavity. The dissipation cavity includes a water jacket for removal of heat generated by the absorptive material coating the dissipation cavity, and this absorptive material has a thickness which is greater near the front wall than near the rear wall. Waves entering the cavity reflect from the rotating reflector, impinging and reflecting multiple times on the absorptive coating of the dissipation cavity, dissipating equal amounts of power on each internal reflection.

  13. Apparatus and method for tuned unsteady flow purging of high pulse rate spark gaps

    DOE Patents [OSTI]

    Thayer, III, William J.

    1990-01-01

    A spark gap switch apparatus is disclosed which is capable of operating at a high pulse rate which comprises an insulated housing; a pair of spaced apart electrodes each having one end thereof within a first bore formed in the housing and defining a spark gap therebetween; a pressure wave reflector in the first bore in the housing and spaced from the spark gap and capable of admitting purge flow; and a second enlarged bore contiguous with the first bore and spaced from the opposite side of the spark gap; whereby pressure waves generated during discharge of a spark across the spark gap will reflect off the wave reflector and back from the enlarged bore to the spark gap to clear from the spark gap hot gases residues generated during the discharge and simultaneously restore the gas density and pressure in the spark gap to its initial value.

  14. Electro-optic high voltage sensor

    DOE Patents [OSTI]

    Davidson, James R.; Seifert, Gary D.

    2003-09-16

    A small sized electro-optic voltage sensor capable of accurate measurement of high voltages without contact with a conductor or voltage source is provided. When placed in the presence of an electric field, the sensor receives an input beam of electromagnetic radiation. A polarization beam displacer separates the input beam into two beams with orthogonal linear polarizations and causes one linearly polarized beam to impinge a crystal at a desired angle independent of temperature. The Pockels effect elliptically polarizes the beam as it travels through the crystal. A reflector redirects the beam back through the crystal and the beam displacer. On the return path, the polarization beam displacer separates the elliptically polarized beam into two output beams of orthogonal linear polarization. The system may include a detector for converting the output beams into electrical signals and a signal processor for determining the voltage based on an analysis of the output beams.

  15. Neutronics Simulations of 237Np Targets to Support Safety-Basis and 238Pu Production Assessment Efforts at the High Flux Isotope Reactor

    SciTech Connect (OSTI)

    Chandler, David; Ellis, Ronald James

    2015-01-01

    Fueled by two highly enriched uranium-bearing fuel elements surrounded by a large concentric ring of beryllium reflector, the High Flux Isotope Reactor (HFIR) provides one of the highest neutron fluxes in the world and is used to produce unique isotopes like plutonium-238. The National Aeronautics and Space Administration use radioisotope thermoelectric generators powered by 238Pu for deep-space missions. As part of the US Department of Energy s task to reestablish the domestic production of 238Pu, a technology demonstration sub-project has been initiated to establish a new 238Pu supply chain. HFIR safety-basis neutronics calculations are being performed to ensure the target irradiations have no adverse impacts on reactor performance and to calculate data required as input to follow-on thermal-structural, thermal-hydraulic and radionuclide/dose analyses. Plutonium-238 production assessments are being performed to estimate the amount of 238Pu that can be produced in HFIR s permanent beryllium reflector. It is estimated that a total of 0.96 1.12 kg 238Pu (~1.28 1.49 kg PuO2 at 85% 238Pu/Pu purity) could be produced per year in HFIR s permanent beryllium reflector irradiation facilities if they are all utilized.

  16. High brightness microwave lamp

    DOE Patents [OSTI]

    Kirkpatrick, Douglas A.; Dolan, James T.; MacLennan, Donald A.; Turner, Brian P.; Simpson, James E.

    2003-09-09

    An electrodeless microwave discharge lamp includes a source of microwave energy, a microwave cavity, a structure configured to transmit the microwave energy from the source to the microwave cavity, a bulb disposed within the microwave cavity, the bulb including a discharge forming fill which emits light when excited by the microwave energy, and a reflector disposed within the microwave cavity, wherein the reflector defines a reflective cavity which encompasses the bulb within its volume and has an inside surface area which is sufficiently less than an inside surface area of the microwave cavity. A portion of the reflector may define a light emitting aperture which extends from a position closely spaced to the bulb to a light transmissive end of the microwave cavity. Preferably, at least a portion of the reflector is spaced from a wall of the microwave cavity. The lamp may be substantially sealed from environmental contamination. The cavity may include a dielectric material is a sufficient amount to require a reduction in the size of the cavity to support the desired resonant mode.

  17. High-efficiency CARM

    SciTech Connect (OSTI)

    Bratman, V.L.; Kol`chugin, B.D.; Samsonov, S.V.; Volkov, A.B.

    1995-12-31

    The Cyclotron Autoresonance Maser (CARM) is a well-known variety of FEMs. Unlike the ubitron in which electrons move in a periodical undulator field, in the CARM the particles move along helical trajectories in a uniform magnetic field. Since it is much simpler to generate strong homogeneous magnetic fields than periodical ones for a relatively low electron energy ({Brit_pounds}{le}1-3 MeV) the period of particles` trajectories in the CARM can be sufficiently smaller than in the undulator in which, moreover, the field decreases rapidly in the transverse direction. In spite of this evident advantage, the number of papers on CARM is an order less than on ubitron, which is apparently caused by the low (not more than 10 %) CARM efficiency in experiments. At the same time, ubitrons operating in two rather complicated regimes-trapping and adiabatic deceleration of particles and combined undulator and reversed guiding fields - yielded efficiencies of 34 % and 27 %, respectively. The aim of this work is to demonstrate that high efficiency can be reached even for a simplest version of the CARM. In order to reduce sensitivity to an axial velocity spread of particles, a short interaction length where electrons underwent only 4-5 cyclotron oscillations was used in this work. Like experiments, a narrow anode outlet of a field-emission electron gun cut out the {open_quotes}most rectilinear{close_quotes} near-axis part of the electron beam. Additionally, magnetic field of a small correcting coil compensated spurious electron oscillations pumped by the anode aperture. A kicker in the form of a sloping to the axis frame with current provided a control value of rotary velocity at a small additional velocity spread. A simple cavity consisting of a cylindrical waveguide section restricted by a cut-off waveguide on the cathode side and by a Bragg reflector on the collector side was used as the CARM-oscillator microwave system.

  18. Intracavity terahertz generation inside a high-energy ultrafast soliton fiber laser

    SciTech Connect (OSTI)

    Matthaeus, Gabor; Ortac, Buelend; Limpert, Jens; Nolte, Stefan; Hohmuth, Rico; Voitsch, Martin; Richter, Wolfgang; Pradarutti, Boris; Tuennermann, Andreas

    2008-12-29

    Intracavity terahertz emission inside a high-energy ultrafast Yb-doped fiber laser is presented. The terahertz radiation is generated by a transient photocurrent induced at the surface of a saturable InGaAs multiquantum well grown by molecular beam epitaxy on top of a semiconductor Bragg reflector. This device simultaneously works as the saturable absorber mirror for initiating and managing the passive mode locking required for the ultrashort pulse operation of the laser system. The maximum terahertz average power achieved is 4.2 {mu}W, which reveals a net conversion efficiency of 3.1x10{sup -5}.

  19. Graphene as a high impedance surface for ultra-wideband electromagnetic waves

    SciTech Connect (OSTI)

    Aldrigo, Martino; Costanzo, Alessandra; Dragoman, Mircea; Dragoman, Daniela

    2013-11-14

    The metals are regularly used as reflectors of electromagnetic fields emitted by antennas ranging from microwaves up to THz. To enhance the reflection and thus the gain of the antenna, metallic high impedance surfaces (HIS) are used. HIS is a planar array of continuous metallic periodic cell surfaces able to suppress surface waves, which cause multipath interference and backward radiation in a narrow bandwidth near the cell resonance. Also, the image currents are reduced, and therefore the antenna can be placed near the HIS. We demonstrate that graphene is acting as a HIS surface in a very large bandwidth, from microwave to THz, suppressing the radiation leakages better than a metal.

  20. High power regenerative laser amplifier

    DOE Patents [OSTI]

    Miller, J.L.; Hackel, L.A.; Dane, C.B.; Zapata, L.E.

    1994-02-08

    A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse. 7 figures.

  1. High power regenerative laser amplifier

    DOE Patents [OSTI]

    Miller, John L.; Hackel, Lloyd A.; Dane, Clifford B.; Zapata, Luis E.

    1994-01-01

    A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse.

  2. Supercell Depletion Studies for Prismatic High Temperature Reactors

    SciTech Connect (OSTI)

    J. Ortensi

    2012-10-01

    The traditional two-step method of analysis is not accurate enough to represent the neutronic effects present in the prismatic high temperature reactor concept. The long range coupling of the various regions in high temperature reactors poses a set of challenges that are not seen in either LWRs or fast reactors. Unlike LWRs, which exhibit large, localized effects, the dominant effects in PMRs are, for the most part, distributed over larger regions, but with lower magnitude. The 1-D in-line treatment currently used in pebble bed reactor analysis is not sufficient because of the 2-D nature of the prismatic blocks. Considerable challenges exist in the modeling of blocks in the vicinity of reflectors, which, for current small modular reactor designs with thin annular cores, include the majority of the blocks. Additional challenges involve the treatment of burnable poisons, operational and shutdown control rods. The use of a large domain for cross section preparation provides a better representation of the neutron spectrum, enables the proper modeling of BPs and CRs, allows the calculation of generalized equivalence theory parameters, and generates a relative power distribution that can be used in compact power reconstruction. The purpose of this paper is to quantify the effects of the reflector, burnable poison, and operational control rods on an LEU design and to delineate an analysis approach for the Idaho National Laboratory. This work concludes that the use of supercells should capture these long-range effects in the preparation of cross sections and along with a set of triangular meshes to treat BPs, and CRs a high fidelity neutronics computation is attainable.

  3. Secondary heat recovery from low-permeability high-temperature reservoir: A possible project in the Larderello Field, Italy

    SciTech Connect (OSTI)

    Gianelli, G.; Squarci, P.; Capocecera, P.

    1997-12-31

    A project of fracture stimulation and secondary heat recovery from the metamorphic reservoir of the Larderello geothermal field could be developed in a next future. Geological and geophysical data suggest that the stimulation can enhance permeability and that the water injection can be recovered as steam. In particular, the area of the project is characterized by the presence of an important seismic reflector which has been explained assuming the presence of fractured rocks filled with high pressure fluids. Extensional and hydraulic fractures can present at temperatures of 300-350{degrees}C, and this makes the experiment of extreme interest.

  4. CX-100009: Categorical Exclusion Determination | Department of...

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

    Development of an Abrasion-Resistant Antisoiling Coating for Front-Surface Reflectors ... high-performance front-surface reflector for Concentrating Solar Power (CSP) application. ...

  5. THERMAL NEUTRONIC REACTOR

    DOE Patents [OSTI]

    Spinrad, B.I.

    1960-01-12

    A novel thermal reactor was designed in which a first reflector formed from a high atomic weight, nonmoderating material is disposed immediately adjacent to the reactor core. A second reflector composed of a moderating material is disposed outwardly of the first reflector. The advantage of this novel reflector arrangement is that the first reflector provides a high slow neutron flux in the second reflector, where irradiation experiments may be conducted with a small effect on reactor reactivity.

  6. Advanced Manufacture of Reflectors (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-09-01

    The University of Arizona is one of the 2012 SunShot CSP R&D awardees for their advanced collectors. This fact sheet explains the motivation, description, and impact of the project.

  7. Correlated-Intensity velocimeter for Arbitrary Reflector

    DOE Patents [OSTI]

    Wang, Zhehui; Luo, Shengnian; Barnes, Cris W.; Paul, Stephen F.

    2008-11-11

    A velocimetry apparatus and method comprising splitting incoming reflected laser light and directing the laser light into first and second arms, filtering the laser light with passband filters in the first and second arms, one having a positive passband slope and the other having a negative passband slope, and detecting the filtered laser light via light intensity detectors following the passband filters in the first and second arms

  8. Ideal light concentrators with reflector gaps

    DOE Patents [OSTI]

    Winston, Roland (Chicago, IL)

    1980-01-01

    A cylindrical or trough-like radiant energy concentration and collection device is provided. The device includes an energy absorber, a glazing enveloping the absorber and a reflective wall. The ideal contour of the reflective wall is determined with reference to a virtual absorber and not the actual absorber cross section.

  9. The Sandia Wave Reflector - Energy Innovation Portal

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

    Reduces design time required for antennas needed in various environments Applications and Industries Voice Communications Mobile Robots Tracking Devices Inventory Reconciliation...

  10. Solar module having reflector between cells

    DOE Patents [OSTI]

    Kardauskas, Michael J.

    1999-01-01

    A photovoltaic module comprising an array of electrically interconnected photovoltaic cells disposed in a planar and mutually spaced relationship between a light-transparent front cover member in sheet form and a back sheet structure is provided with a novel light-reflecting means disposed between adjacent cells for reflecting light falling in the areas between cells back toward said transparent cover member for further internal reflection onto the solar cells. The light-reflecting comprises a flexible plastic film that has been embossed so as to have a plurality of small V-shaped grooves in its front surface, and a thin light-reflecting coating on said front surface, the portions of said coating along the sides of said grooves forming light-reflecting facets, said grooves being formed so that said facets will reflect light impinging thereon back into said transparent cover sheet with an angle of incidence greater than the critical angle, whereby substantially all of the reflected light will be internally reflected from said cover sheet back to said solar modules, thereby increasing the current output of the module.

  11. Development of metal-ceramic coaxial cable Fabry-Pérot interferometric sensors for high temperature monitoring

    SciTech Connect (OSTI)

    Trontz, Adam; Cheng, Baokai; Zeng, Shixuan; Xiao, Hai; Dong, Junhang

    2015-09-25

    Metal-ceramic coaxial cable Fabry-Pérot interferometric (MCCC-FPI) sensors have been developed using a stainless steel tube and a stainless steel wire as the outer and inner conductors, respectively; a tubular α-alumina insulator; and a pair of air gaps created in the insulator along the cable to serve as weak reflectors for the transmitting microwave (MW) signal. The MCCC-FPI sensors have been demonstrated for high temperature measurements using MW signals in a frequency range of 2–8 GHz. The temperature measurement is achieved by monitoring the frequency shift (Δƒ) of the MW interferogram reflected from the pair of weak reflectors. The MW sensor exhibited excellent linear dependence of Δƒ on temperature; small measurement deviations (±2.7%); and fast response in a tested range of 200–500 °C. The MCCC has the potential for further developing multipoint FPI sensors in a single-cable to achieve in situ and continuous measurement of spatially distributed temperature in harsh environments.

  12. Development of metal-ceramic coaxial cable Fabry-Pérot interferometric sensors for high temperature monitoring

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

    Trontz, Adam; Cheng, Baokai; Zeng, Shixuan; Xiao, Hai; Dong, Junhang

    2015-09-25

    Metal-ceramic coaxial cable Fabry-Pérot interferometric (MCCC-FPI) sensors have been developed using a stainless steel tube and a stainless steel wire as the outer and inner conductors, respectively; a tubular α-alumina insulator; and a pair of air gaps created in the insulator along the cable to serve as weak reflectors for the transmitting microwave (MW) signal. The MCCC-FPI sensors have been demonstrated for high temperature measurements using MW signals in a frequency range of 2–8 GHz. The temperature measurement is achieved by monitoring the frequency shift (Δƒ) of the MW interferogram reflected from the pair of weak reflectors. The MW sensormore » exhibited excellent linear dependence of Δƒ on temperature; small measurement deviations (±2.7%); and fast response in a tested range of 200–500 °C. The MCCC has the potential for further developing multipoint FPI sensors in a single-cable to achieve in situ and continuous measurement of spatially distributed temperature in harsh environments.« less

  13. Fuel Grading Study on a Low-Enriched Uranium Fuel Design for the High Flux Isotope Reactor

    SciTech Connect (OSTI)

    Ilas, Germina; Primm, Trent

    2009-11-01

    An engineering design study that would enable the conversion of the High Flux Isotope Reactor (HFIR) from high-enriched uranium to low-enriched uranium fuel is ongoing at Oak Ridge National Laboratory. The computational models used to search for a low-enriched uranium (LEU) fuel design that would meet the requirements for the conversion study, and the recent results obtained with these models during FY 2009, are documented and discussed in this report. Estimates of relevant reactor performance parameters for the LEU fuel core are presented and compared with the corresponding data for the currently operating high-enriched uranium fuel core. These studies indicate that the LEU fuel design would maintain the current performance of the HFIR with respect to the neutron flux to the central target region, reflector, and beam tube locations.

  14. Annular core for Modular High-Temperature Gas-Cooled Reactor (MHTGR)

    SciTech Connect (OSTI)

    Turner, R.F.; Baxter, A.M.; Stansfield, O.M.; Vollman, R.E.

    1987-08-01

    The active core of the 350 MW(t) MHTGR is annular in configuration, shaped to provide a large external surface-to-volume ratio for the transport of heat radially to the reactor vessel in case of a loss of coolant flow. For a given fuel temperature limit, the annular core provides approximately 40% greater power output over a typical cylindrical configuration. The reactor core is made up of columns of hexagonal blocks, each 793-mm high and 360-mm wide. The active core is 3.5 m in o.d., 1.65 m in i.d., and 7.93-m tall. Fuel elements contain TRISO-coated microspheres of 19.8% enriched uranium oxycarbide and of fertile thorium oxide. The core is controlled by 30 control rods which enter the inner and outer side reflectors from above.

  15. Low-Enriched Uranium Fuel Design with Two-Dimensional Grading for the High Flux Isotope Reactor

    SciTech Connect (OSTI)

    Ilas, Germina [ORNL; Primm, Trent [ORNL

    2011-05-01

    An engineering design study of the conversion of the High Flux Isotope Reactor (HFIR) from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel is ongoing at Oak Ridge National Laboratory. The computational models developed during fiscal year 2010 to search for an LEU fuel design that would meet the requirements for the conversion and the results obtained with these models are documented and discussed in this report. Estimates of relevant reactor performance parameters for the LEU fuel core are presented and compared with the corresponding data for the currently operating HEU fuel core. The results obtained indicate that the LEU fuel design would maintain the current performance of the HFIR with respect to the neutron flux to the central target region, reflector, and beam tube locations under the assumption that the operating power for the reactor fueled with LEU can be increased from the current value of 85 MW to 100 MW.

  16. Optical coatings of variable refractive index and high laser-resistance from physical-vapor-deposited perfluorinated amorphous polymer

    DOE Patents [OSTI]

    Chow, Robert; Loomis, Gary E.; Thomas, Ian M.

    1999-01-01

    Variable index optical single-layers, optical multilayer, and laser-resistant coatings were made from a perfluorinated amorphous polymer material by physical vapor deposition. This was accomplished by physically vapor depositing a polymer material, such as bulk Teflon AF2400, for example, to form thin layers that have a very low refractive index (.about.1.10-1.31) and are highly transparent from the ultra-violet through the near infrared regime, and maintain the low refractive index of the bulk material. The refractive index can be varied by simply varying one process parameter, either the deposition rate or the substrate temperature. The thus forming coatings may be utilized in anti-reflectors and graded anti-reflection coatings, as well as in optical layers for laser-resistant coatings at optical wavelengths of less than about 2000 nm.

  17. Optical coatings of variable refractive index and high laser-resistance from physical-vapor-deposited perfluorinated amorphous polymer

    DOE Patents [OSTI]

    Chow, R.; Loomis, G.E.; Thomas, I.M.

    1999-03-16

    Variable index optical single-layers, optical multilayer, and laser-resistant coatings were made from a perfluorinated amorphous polymer material by physical vapor deposition. This was accomplished by physically vapor depositing a polymer material, such as bulk Teflon AF2400, for example, to form thin layers that have a very low refractive index (ca. 1.10--1.31) and are highly transparent from the ultra-violet through the near infrared regime, and maintain the low refractive index of the bulk material. The refractive index can be varied by simply varying one process parameter, either the deposition rate or the substrate temperature. The thus forming coatings may be utilized in anti-reflectors and graded anti-reflection coatings, as well as in optical layers for laser-resistant coatings at optical wavelengths of less than about 2000 nm. 2 figs.

  18. Research on stable, high-efficiency amorphous silicon multijunction modules. Semiannual subcontract report, 1 March 1993--30 November 1993

    SciTech Connect (OSTI)

    Guha, S.

    1994-03-01

    This report describes the progress made during the first half of Phase III of the R&D program to obtain high-efficiency amorphous silicon alloy multijunction modules. The highlight of the work includes (1) demonstration of the world`s highest initial module efficiency (area of 0.09 m{sup 2}) of 11.4% as confirmed by NREL, and (2) demonstration of stable module efficiency of 9.5% after 1-sun light soaking for 1000 h at 50{degrees}C. In addition, fundamental studies were carried out to improve material properties of the component cells of the multijunction structure and to understand the optical losses associated with the back reflector.

  19. Highly Efficient Small Form Factor LED Retrofit Lamp

    SciTech Connect (OSTI)

    Steven Allen; Fred Palmer; Ming Li

    2011-09-11

    This report summarizes work to develop a high efficiency LED-based MR16 lamp downlight at OSRAM SYLVANIA under US Department of Energy contract DE-EE0000611. A new multichip LED package, electronic driver, and reflector optic were developed for these lamps. At steady-state, the lamp luminous flux was 409 lumens (lm), luminous efficacy of 87 lumens per watt (LPW), CRI (Ra) of 87, and R9 of 85 at a correlated color temperature (CCT) of 3285K. The LED alone achieved 120 lumens per watt efficacy and 600 lumen flux output at 25 C. The driver had 90% electrical conversion efficiency while maintaining excellent power quality with power factor >0.90 at a power of only 5 watts. Compared to similar existing MR16 lamps using LED sources, these lamps had much higher efficacy and color quality. The objective of this work was to demonstrate a LED-based MR16 retrofit lamp for replacement of 35W halogen MR16 lamps having (1) luminous flux of 500 lumens, (2) luminous efficacy of 100 lumens per watt, (3) beam angle less than 40{sup o} and center beam candlepower of at least 1000 candelas, and (4) excellent color quality.

  20. High power laser heating of low absorption materials

    SciTech Connect (OSTI)

    Olson, K.; Talghader, J.; Ogloza, A.; Thomas, J.

    2014-09-28

    A model is presented and confirmed experimentally that explains the anomalous behavior observed in continuous wave (CW) excitation of thermally isolated optics. Distributed Bragg Reflector (DBR) high reflective optical thin film coatings of HfO₂ and SiO₂were prepared with a very low absorption, about 7 ppm, measured by photothermal common-path interferometry. When illuminated with a 17 kW CW laser for 30 s, the coatings survived peak irradiances of 13 MW/cm², on 500 μm diameter spot cross sections. The temperature profile of the optical surfaces was measured using a calibrated thermal imaging camera for illuminated spot sizes ranging from 500 μm to 5 mm; about the same peak temperatures were recorded regardless of spot size. This phenomenon is explained by solving the heat equation for an optic of finite dimensions and taking into account the non-idealities of the experiment. An analytical result is also derived showing the relationship between millisecond pulse to CW laser operation where (1) the heating is proportional to the laser irradiance (W/m²) for millisecond pulses, (2) the heating is proportional to the beam radius (W/m) for CW, and (3) the heating is proportional to W/m∙ tan⁻¹(√(t)/m) in the transition region between the two.

  1. Research on stable, high-efficiency amorphous silicon multijunction modules

    SciTech Connect (OSTI)

    Ghosh, M.; DelCueto, J.: Kampas, F.; Xi, J. )

    1993-02-01

    This report describes results from the first phase of a three-phase contract for the development of stable, high-efficiency, same-band-gap, amorphous silicon (a-Si) multijunction photovoltaic (PV) modules. The program involved improving the properties of individual layers of semiconductor and non-semiconductor materials and small-area single-junction and multijunction devices, as well as the multijunction modules. The semiconductor materials research was performed on a-Si p, i, and n layers, and on microcrystalline silicon n layers. These were deposited using plasma-enhanced chemical vapor deposition. The non-semiconductor materials studied were tin oxide, for use as a transparent-conducting-oxide (TCO), and zinc oxide, for use as a back reflector and as a buffer layer between the TCO and the semiconductor layers. Tin oxide was deposited using atmospheric-pressure chemical vapor deposition. Zinc oxide was deposited using magnetron sputtering. The research indicated that the major challenge in the fabrication of a-Si multijunction PV modules is the contact between the two p-i-n cells. A structure that has low optical absorption but that also facilitates the recombination of electrons from the first p-i-n structure with holes from the second p-i-n structure is required. Non-semiconductor layers and a-Si semiconductor layers were tested without achieving the desired result.

  2. Radiation dosimetry at the BNL High Flux Beam Reactor

    SciTech Connect (OSTI)

    Holden, N.E.; Hu, J.P.; Reciniello, R.N.

    1998-02-01

    The HFBR is a heavy water, D{sub 2}O, cooled and moderated reactor with twenty-eight fuel elements containing a maximum of 9.8 kilograms of {sup 235}U. The core is 53 cm high and 48 cm in diameter and has an active volume of 97 liters. The HFBR, which was designed to operate at forty mega-watts, 40 NW, was upgraded to operate at 60 NW. Since 1991, it has operated at 30 MW. In a normal 30 MW operating cycle the HFBR operates 24 hours a day for thirty days, with a six to fourteen day shutdown period for refueling and maintenance work. While most reactors attempts to minimize the escape of neutrons from the core, the HFBR`s D{sub 2}O design allows the thermal neutron flux to peak in the reflector region and maximizes the number of thermal neutrons available to nine horizontal external beams, H-1 to H-9. The HFBR neutron dosimetry effort described here compares measured and calculated energy dependent neutron and gamma ray flux densities and/or dose rates at horizontal beam lines and vertical irradiation thimbles.

  3. Structural, optical and waveguiding properties improvement of SiO{sub 2}/TiO{sub 2} Bragg reflectors processed by the sol–gel method under the effect of Ni-doped TiO{sub 2} and annealing duration

    SciTech Connect (OSTI)

    Sedrati, H.; Bensaha, R.; Bensouyad, H.; Miska, P.; Robert, S.

    2014-09-15

    Highlights: • The formation of anatase phase only, whatever are Ni content and annealing duration. • Transmission and PL spectra redshifted with Ni content and annealing duration. • PL lowering with Ni content is due to the recombination rate of electron–hole reduction. • Annealing duration increases the recombination rate and then the PL intensity rises. • Increasing Ni content improves waveguiding properties and then two TE modes appear. - Abstract: We investigated the nickel doped TiO{sub 2} layer and annealing duration effects on SiO{sub 2}/TiO{sub 2} Bragg reflectors. The films crystallize in pure anatase phase whatever is the Ni content and the annealing duration. In UV–vis-NIR analyses, variations of width, position and transmission coefficient of the stop-band were observed. The PL spectra red-shifted when the Ni content and annealing duration increased. As the annealing duration increases, an additional sharp emission peak appears around 867 nm, indicating a reduced number of defects. As Ni content increased, the M-lines spectroscopy shows two transverse electric polarization guided modes TE{sub 0} and TE{sub 1}, which indicates a decreased refractive index and an increased film thickness.

  4. High PRF high current switch

    DOE Patents [OSTI]

    Moran, Stuart L.; Hutcherson, R. Kenneth

    1990-03-27

    A triggerable, high voltage, high current, spark gap switch for use in pu power systems. The device comprises a pair of electrodes in a high pressure hydrogen environment that is triggered by introducing an arc between one electrode and a trigger pin. Unusually high repetition rates may be obtained by undervolting the switch, i.e., operating the trigger at voltages much below the self-breakdown voltage of the device.

  5. Low reflectance high power RF load

    DOE Patents [OSTI]

    Ives, R. Lawrence; Mizuhara, Yosuke M.

    2016-02-02

    A load for traveling microwave energy has an absorptive volume defined by cylindrical body enclosed by a first end cap and a second end cap. The first end cap has an aperture for the passage of an input waveguide with a rotating part that is coupled to a reflective mirror. The inner surfaces of the absorptive volume consist of a resistive material or are coated with a coating which absorbs a fraction of incident RF energy, and the remainder of the RF energy reflects. The angle of the reflector and end caps is selected such that reflected RF energy dissipates an increasing percentage of the remaining RF energy at each reflection, and the reflected RF energy which returns to the rotating mirror is directed to the back surface of the rotating reflector, and is not coupled to the input waveguide. Additionally, the reflector may have a surface which generates a more uniform power distribution function axially and laterally, to increase the power handling capability of the RF load. The input waveguide may be corrugated for HE11 mode input energy.

  6. Development of high, stable-efficiency triple-junction a-Si alloy solar cells. Final technical report

    SciTech Connect (OSTI)

    Deng, X.; Jones, S.J.; Liu, T.; Izu, M.

    1998-04-01

    This report summarizes Energy Conversion Devices, Inc.`s (ECD) research under this program. ECD researchers explored the deposition of a-Si at high rates using very-high-frequency plasma MHz, and compared these VHF i-layers with radio-frequency (RF) plasma-deposited i-layers. ECD conducted comprehensive research to develop a {mu}c-Si p{sup +} layer using VHF deposition process with the objectives of establishing a wider process window for the deposition of high-quality p{sup +} materials and further enhancing their performance of a-Si solar cells by improving its p-layers. ECD optimized the deposition of the intrinsic a-Si layer and the boron-doped {mu}c-Si p{sup +} layer to improve the V{sub oc}. Researchers deposited wide-bandgap a-Si films using high hydrogen dilution; investigated the deposition of the ZnO layer (for use in back-reflector) using a sputter deposition process involving metal Zn targets; and obtained a baseline fabrication for single-junction a-Si n-i-p devices with 10.6% initial efficiency and a baseline fabrication for triple-junction a-Si devices with 11.2% initial efficiency. ECD researchers also optimized the deposition parameters for a-SiGe with high Ge content; designed a novel structure for the p-n tunnel junction (recombination layer) in a multiple-junction solar cell; and demonstrated, in n-i-p solar cells, the improved stability of a-Si:H:F materials when deposited using a new fluorine precursor. Researchers investigated the use of c-Si(n{sup +})/a-Si alloy/Pd Schottky barrier device as a tool for the effective evaluation of photovoltaic performance on a-Si alloy materials. Through alterations in the deposition conditions and system hardware, researchers improved their understanding for the deposition of uniform and high-quality a-Si and a-SiGe films over large areas. ECD researchers also performed extensive research to optimize the deposition process of the newly constructed 5-MW back-reflector deposition machine.

  7. High Resolution/High Fidelity Seismic Imaging and Parameter Estimation for Geological Structure and Material Characterization

    SciTech Connect (OSTI)

    Ru-Shan Wu; Xiao-Bi Xie

    2008-06-08

    Our proposed work on high resolution/high fidelity seismic imaging focused on three general areas: (1) development of new, more efficient, wave-equation-based propagators and imaging conditions, (2) developments towards amplitude-preserving imaging in the local angle domain, in particular, imaging methods that allow us to estimate the reflection as a function of angle at a layer boundary, and (3) studies of wave inversion for local parameter estimation. In this report we summarize the results and progress we made during the project period. The report is divided into three parts, totaling 10 chapters. The first part is on resolution analysis and its relation to directional illumination analysis. The second part, which is composed of 6 chapters, is on the main theme of our work, the true-reflection imaging. True-reflection imaging is an advanced imaging technology which aims at keeping the image amplitude proportional to the reflection strength of the local reflectors or to obtain the reflection coefficient as function of reflection-angle. There are many factors which may influence the image amplitude, such as geometrical spreading, transmission loss, path absorption, acquisition aperture effect, etc. However, we can group these into two categories: one is the propagator effect (geometric spreading, path losses); the other is the acquisition-aperture effect. We have made significant progress in both categories. We studied the effects of different terms in the true-amplitude one-way propagators, especially the terms including lateral velocity variation of the medium. We also demonstrate the improvements by optimizing the expansion coefficients in different terms. Our research also includes directional illumination analysis for both the one-way propagators and full-wave propagators. We developed the fast acquisition-aperture correction method in the local angle-domain, which is an important element in the true-reflection imaging. Other developments include the super

  8. Laser beam alignment system

    DOE Patents [OSTI]

    Kasner, William H.; Racki, Daniel J.; Swenson, Clark E.

    1984-01-01

    A plurality of pivotal reflectors direct a high-power laser beam onto a workpiece, and a rotatable reflector is movable to a position wherein it intercepts the beam and deflects a major portion thereof away from its normal path, the remainder of the beam passing to the pivotal reflectors through an aperture in the rotating reflector. A plurality of targets are movable to positions intercepting the path of light traveling to the pivotal reflectors, and a preliminary adjustment of the latter is made by use of a low-power laser beam reflected from the rotating reflector, after which the same targets are used to make a final adjustment of the pivotal reflectors with the portion of the high-power laser beam passed through the rotating reflector.

  9. High e

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

    e ne rgy data s am ple ● NuMI beam events provide an useful calibration sample ● Collected over 70K candidates before shutdown The highest energy events are prim arily from kaon decays. Two sam ples at high energy provide normalization and shape inform ation for kaon backgrounds to oscillation analysis: ● ν e events passing oscillation event selection cuts ● ν µ induced CCQE, CCπ+events Reconstructed neutrino energy EνQE(GeV) ν from other particles ν from pions ν from Kaons -

  10. Convection venting lensed reflector-type compact fluorescent lamp system

    DOE Patents [OSTI]

    Pelton, Bruce A.; Siminovitch, Michael

    1997-01-01

    Disclosed herein is a fluorescent lamp housing assembly capable of providing convection cooling to the lamp and the ballast. The lens of the present invention includes two distinct portions, a central portion and an apertured portion. The housing assembly further includes apertures so that air mass is able to freely move up through the assembly and out ventilation apertures.

  11. Advanced Manufacture of Reflectors- FY13 Q1

    Broader source: Energy.gov [DOE]

    This document summarizes the progress of this University of Arizona project, funded by SunShot, for the first quarter of fiscal year 2013.

  12. Angle amplifying optics using plane and ellipsoidal reflectors

    DOE Patents [OSTI]

    Glass, Alexander J.

    1977-01-01

    An optical system for providing a wide angle input beam into ellipsoidal laser fusion target illumination systems. The optical system comprises one or more pairs of centrally apertured plane and ellipsoidal mirrors disposed to accept the light input from a conventional lens of modest focal length and thickness, to increase the angular divergence thereof to a value equivalent to that of fast lenses, and to direct the light into the ellipsoidal target illumination system.

  13. Prisms with total internal reflection as solar reflectors

    DOE Patents [OSTI]

    Rabl, Arnulf; Rabl, Veronika

    1978-01-01

    An improved reflective wall for radiant energy collection and concentration devices is provided. The wall is comprised of a plurality of prisms whose frontal faces are adjacent and which reflect the desired radiation by total internal reflection.

  14. Code division multiple access signaling for modulated reflector technology

    DOE Patents [OSTI]

    Briles, Scott D.

    2012-05-01

    A method and apparatus for utilizing code division multiple access in modulated reflectance transmissions comprises the steps of generating a phase-modulated reflectance data bit stream; modifying the modulated reflectance data bit stream; providing the modified modulated reflectance data bit stream to a switch that connects an antenna to an infinite impedance in the event a "+1" is to be sent, or connects the antenna to ground in the event a "0" or a "-1" is to be sent.

  15. Convection venting lensed reflector-type compact fluorescent lamp system

    DOE Patents [OSTI]

    Pelton, B.A.; Siminovitch, M.

    1997-07-29

    Disclosed herein is a fluorescent lamp housing assembly capable of providing convection cooling to the lamp and the ballast. The lens of the present invention includes two distinct portions, a central portion and an apertured portion. The housing assembly further includes apertures so that air mass is able to freely move up through the assembly and out ventilation apertures. 12 figs.

  16. Photovoltaic concentrator with plastic-film reflector. Final report

    SciTech Connect (OSTI)

    Not Available

    1982-06-01

    A 4m diameter reflective film, parabolic dish concentrator proposed for use with a photovoltaic array has been designed, fabricated, and tested. The concentrator is made from aluminized film gores (wedge shaped pieces) that are taped together along their edges to form a dish. The shape of the dish is maintained by a pressure difference between the front and back. The deep dish was designed to illuminate a cylindrical receiver populated by solar cells with a geometric concentration ratio of 145. Three full scale dishes were made in sequence, each using improvements suggested by the previous design. They were tested with a laser to determine surface errors and flux uniformity on the target.

  17. Imaging with Spherically Bent Crystals or Reflectors (Technical...

    Office of Scientific and Technical Information (OSTI)

    This type of spectrometer was thoroughly tested on NSTX and Alcator C-Mod, and its concept was recently adopted for the design of the ITER crystal spectrometers. Part II describes ...

  18. Imaging with Spherically Bent Crystals or Reflectors (Technical...

    Office of Scientific and Technical Information (OSTI)

    Close Cite: Bibtex Format Close 0 pages in this document matching the terms "" Search For Terms: Enter terms in the toolbar above to search the full text of this document for ...

  19. Advanced Manufacture of Reflectors- FY12 Q4

    Broader source: Energy.gov [DOE]

    This document summarizes the progress of this University of Arizona project, funded by SunShot, for the fourth quarter of fiscal year 2012.

  20. Beam spoiling a reflector antenna with conducting shim. (Technical...

    Office of Scientific and Technical Information (OSTI)

    science and technology. A paper copy of this document is also available for sale to the public from the National Technical Information Service, Springfield, VA at www.ntis.gov. A...

  1. Radar cross section of triangular trihedral reflector with extended...

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

    Report Number(s): SAND2009-2993 TRN: US201016%%1855 DOE Contract Number: AC04-94AL85000 Resource Type: Technical Report Research Org: Sandia National Laboratories Sponsoring Org: ...

  2. Monolithically interconnected GaAs solar cells: A new interconnection technology for high voltage solar cell output

    SciTech Connect (OSTI)

    Dinetta, L.C.; Hannon, M.H.

    1995-10-01

    Photovoltaic linear concentrator arrays can benefit from high performance solar cell technologies being developed at AstroPower. Specifically, these are the integration of thin GaAs solar cell and epitaxial lateral overgrowth technologies with the application of monolithically interconnected solar cell (MISC) techniques. This MISC array has several advantages which make it ideal for space concentrator systems. These are high system voltage, reliable low cost monolithically formed interconnections, design flexibility, costs that are independent of array voltage, and low power loss from shorts, opens, and impact damage. This concentrator solar cell will incorporate the benefits of light trapping by growing the device active layers over a low-cost, simple, PECVD deposited silicon/silicon dioxide Bragg reflector. The high voltage-low current output results in minimal 12R losses while properly designing the device allows for minimal shading and resistance losses. It is possible to obtain open circuit voltages as high as 67 volts/cm of solar cell length with existing technology. The projected power density for the high performance device is 5 kW/m for an AMO efficiency of 26% at 1 5X. Concentrator solar cell arrays are necessary to meet the power requirements of specific mission platforms and can supply high voltage power for electric propulsion systems. It is anticipated that the high efficiency, GaAs monolithically interconnected linear concentrator solar cell array will enjoy widespread application for space based solar power needs. Additional applications include remote man-portable or ultra-light unmanned air vehicle (UAV) power supplies where high power per area, high radiation hardness and a high bus voltage or low bus current are important. The monolithic approach has a number of inherent advantages, including reduced cost per interconnect and increased reliability of array connections. There is also a high potential for a large number of consumer products.

  3. High-efficiency silicon heterojunction solar cells: Status and perspectives

    SciTech Connect (OSTI)

    De Wolf, S.; Geissbuehler, J.; Loper, P.; Martin de Nicholas, S.; Seif, J.; Tomasi, A.; Ballif, C.

    2015-05-11

    Silicon heterojunction technology (HJT) uses silicon thin-film deposition techniques to fabricate photovoltaic devices from mono-crystalline silicon wafers (c-Si). This enables energy-conversion efficiencies above 21 %, also at industrial-production level. In this presentation we review the present status of this technology and point out recent trends. We first discuss how the properties of thin hydrogenated amorphous silicon (a-Si:H) films can be exploited to fabricate passivating contacts, which is the key to high- efficiency HJT solar cells. Such contacts enable very high operating voltages, approaching the theoretical limits, and yield small temperature coefficients. With this approach, an increasing number of groups are reporting devices with conversion efficiencies well over 20 % on both-sides contacted n-type cells, Panasonic leading the field with 24.7 %. Exciting results have also been obtained on p-type wafers. Despite these high voltages, important efficiency gains can still be made in fill factor and optical design. This requires improved understanding of carrier transport across device interfaces and reduced parasitic absorption in HJT solar cells. For the latter, several strategies can be followed: Short-wavelength losses can be reduced by replacing the front a-Si:H films with wider-bandgap window layers, such as silicon alloys or even metal oxides. Long- wavelength losses are mitigated by introducing new high-mobility TCO’s such as hydrogenated indium oxide, and also by designing new rear reflectors. Optical shadow losses caused by the front metallization grid are significantly reduced by replacing printed silver electrodes with fine-line plated copper contacts, leading also to possible cost advantages. The ultimate approach to minimize optical losses is the implementation of back-contacted architectures, which are completely devoid of grid shadow losses and parasitic absorption in the front layers can be minimized irrespective of electrical

  4. High-efficiency silicon heterojunction solar cells: Status and perspectives

    SciTech Connect (OSTI)

    De Wolf, S.

    2015-04-27

    Silicon heterojunction technology (HJT) uses silicon thin-film deposition techniques to fabricate photovoltaic devices from mono-crystalline silicon wafers (c-Si). This enables energy-conversion efficiencies above 21 %, also at industrial-production level. In this presentation we review the present status of this technology and point out recent trends. We first discuss how the properties of thin hydrogenated amorphous silicon (a-Si:H) films can be exploited to fabricate passivating contacts, which is the key to high- efficiency HJT solar cells. Such contacts enable very high operating voltages, approaching the theoretical limits, and yield small temperature coefficients. With this approach, an increasing number of groups are reporting devices with conversion efficiencies well over 20 % on n-type wafers, Panasonic leading the field with 24.7 %. Exciting results have also been obtained on p-type wafers. Despite these high voltages, important efficiency gains can still be made in fill factor and optical design. This requires improved understanding of carrier transport across device interfaces and reduced parasitic absorption in HJT solar cells. For the latter, several strategies can be followed: Short- wavelength losses can be reduced by replacing the front a-Si:H films with wider-bandgap window layers, such as silicon alloys or even metal oxides. Long-wavelength losses are mitigated by introducing new high-mobility TCO’s such as hydrogenated indium oxide, and also by designing new rear reflectors. Optical shadow losses caused by the front metalisation grid are significantly reduced by replacing printed silver electrodes with fine-line plated copper contacts, leading also to possible cost advantages. The ultimate approach to minimize optical losses is the implementation of back-contacted architectures, which are completely devoid of grid shadow losses and parasitic absorption in the front layers can be minimized irrespective of electrical transport requirements. The

  5. High efficiency low cost thin film silicon solar cell design and method for making

    DOE Patents [OSTI]

    Sopori, B.L.

    1999-04-27

    A semiconductor device is described having a substrate, a conductive intermediate layer deposited onto said substrate, wherein the intermediate layer serves as a back electrode, an optical reflector, and an interface for impurity gettering, and a semiconductor layer deposited onto said intermediate layer, wherein the semiconductor layer has a grain size at least as large as the layer thickness, and preferably about ten times the layer thickness. The device is formed by depositing a metal layer on a substrate, depositing a semiconductive material on the metal-coated substrate to produce a composite structure, and then optically processing the composite structure by illuminating it with infrared electromagnetic radiation according to a unique time-energy profile that first produces pits in the backside surface of the semiconductor material, then produces a thin, highly reflective, low resistivity alloy layer over the entire area of the interface between the semiconductor material and the metal layer, and finally produces a grain-enhanced semiconductor layer. The time-energy profile includes increasing the energy to a first energy level to initiate pit formation and create the desired pit size and density, then ramping up to a second energy level in which the entire device is heated to produce an interfacial melt, and finally reducing the energy to a third energy level and holding for a period of time to allow enhancement in the grain size of the semiconductor layer. 9 figs.

  6. Uranium Oxide as a Highly Reflective Coating from 100-400 eV

    SciTech Connect (OSTI)

    Sandberg, Richard L.; Allred, David D.; Bissell, Luke J.; Johnson, Jed E.; Turley, R. Steven

    2004-05-12

    We present the measured reflectances (Beamline 6.3.2, ALS at LBNL) of naturally oxidized uranium and naturally oxidized nickel thin films from 100-460 eV (2.7 to 11.6 nm) at 5 and 15 degrees grazing incidence. These show that uranium, as UO2, can fulfill its promise as the highest known single surface reflector for this portion of the soft x-ray region, being nearly twice as reflective as nickel in the 124-250 eV (5-10 nm) region. This is due to its large index of refraction coupled with low absorption. Nickel is commonly used in soft x-ray applications in astronomy and synchrotrons. (Its reflectance at 10 deg. exceeds that of Au and Ir for most of this range.) We prepared uranium and nickel thin films via DC-magnetron sputtering of a depleted U target and resistive heating evaporation respectively. Ambient oxidation quickly brought the U sample to UO2 (total thickness about 30 nm). The nickel sample (50 nm) also acquired a thin native oxide coating (<2nm). Though the density of U in UO2 is only half of the metal, its reflectance is high and it is relatively stable against further changes.

  7. High efficiency low cost thin film silicon solar cell design and method for making

    DOE Patents [OSTI]

    Sopori, Bhushan L.

    1999-01-01

    A semiconductor device having a substrate, a conductive intermediate layer deposited onto said substrate, wherein the intermediate layer serves as a back electrode, an optical reflector, and an interface for impurity gettering, and a semiconductor layer deposited onto said intermediate layer, wherein the semiconductor layer has a grain size at least as large as the layer thickness, and preferably about ten times the layer thickness. The device is formed by depositing a metal layer on a substrate, depositing a semiconductive material on the metal-coated substrate to produce a composite structure, and then optically processing the composite structure by illuminating it with infrared electromagnetic radiation according to a unique time-energy profile that first produces pits in the backside surface of the semiconductor material, then produces a thin, highly reflective, low resistivity alloy layer over the entire area of the interface between the semiconductor material and the metal layer, and finally produces a grain-enhanced semiconductor layer. The time-energy profile includes increasing the energy to a first energy level to initiate pit formation and create the desired pit size and density, then ramping up to a second energy level in which the entire device is heated to produce an interfacial melt, and finally reducing the energy to a third energy level and holding for a period of time to allow enhancement in the grain size of the semiconductor layer.

  8. High efficiency, low cost, thin film silicon solar cell design and method for making

    DOE Patents [OSTI]

    Sopori, Bhushan L.

    2001-01-01

    A semiconductor device having a substrate, a conductive intermediate layer deposited onto said substrate, wherein the intermediate layer serves as a back electrode, an optical reflector, and an interface for impurity gettering, and a semiconductor layer deposited onto said intermediate layer, wherein the semiconductor layer has a grain size at least as large as the layer thickness, and preferably about ten times the layer thickness. The device is formed by depositing a metal layer on a substrate, depositing a semiconductive material on the metal-coated substrate to produce a composite structure, and then optically processing the composite structure by illuminating it with infrared electromagnetic radiation according to a unique time-energy profile that first produces pits in the backside surface of the semiconductor material, then produces a thin, highly reflective, low resistivity alloy layer over the entire area of the interface between the semiconductor material and the metal layer, and finally produces a grain-enhanced semiconductor layer. The time-energy profile includes increasing the energy to a first energy level to initiate pit formation and create the desired pit size and density, then ramping up to a second energy level in which the entire device is heated to produce an interfacial melt, and finally reducing the energy to a third energy level and holding for a period of time to allow enhancement in the grain size of the semiconductor layer.

  9. High Energy Physics

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

    High Energy Physics High Energy Physics Investigating the field of high energy physics ... Through the Office of High Energy Physics (HEP), Los Alamos conducts research in particle ...

  10. Office of Chief Financial Officer

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

    high optical accuracy reflectors, reduce collector structure weight and material, develop lean and rapid methods for manufacturing, assembly and installation, develop highly...

  11. Research on stable, high-efficiency amorphous silicon multijunction modules. Annual subcontract report, 1 December 1991--31 October 1992

    SciTech Connect (OSTI)

    Ghosh, M.; DelCueto, J.: Kampas, F.; Xi, J.

    1993-02-01

    This report describes results from the first phase of a three-phase contract for the development of stable, high-efficiency, same-band-gap, amorphous silicon (a-Si) multijunction photovoltaic (PV) modules. The program involved improving the properties of individual layers of semiconductor and non-semiconductor materials and small-area single-junction and multijunction devices, as well as the multijunction modules. The semiconductor materials research was performed on a-Si p, i, and n layers, and on microcrystalline silicon n layers. These were deposited using plasma-enhanced chemical vapor deposition. The non-semiconductor materials studied were tin oxide, for use as a transparent-conducting-oxide (TCO), and zinc oxide, for use as a back reflector and as a buffer layer between the TCO and the semiconductor layers. Tin oxide was deposited using atmospheric-pressure chemical vapor deposition. Zinc oxide was deposited using magnetron sputtering. The research indicated that the major challenge in the fabrication of a-Si multijunction PV modules is the contact between the two p-i-n cells. A structure that has low optical absorption but that also facilitates the recombination of electrons from the first p-i-n structure with holes from the second p-i-n structure is required. Non-semiconductor layers and a-Si semiconductor layers were tested without achieving the desired result.

  12. Portable Doppler interferometer system for shock diagnostics and high speed motion

    SciTech Connect (OSTI)

    Fleming, K.J.; Crump, O.B. Jr.

    1994-05-01

    VISAR (Velocity Interferometer System for Any Reflector) is a system that uses the Doppler effect and is widely used for measuring the velocity of projectiles, detonations, flying plates, shock pressures (particle velocity) and other high speed/high acceleration motion. Other methods of measurement such as accelerometers and pressure gauges have disadvantages in that they are sensitive to radiation, electromagnetic pulses, and their mass can drastically alter the velocity of the projectile. VISAR uses single frequency-single mode laser fight focused onto a target of interest. Reflected fight from the target is collected and sent through a modified, unequal leg Michelson interferometer. In the interferometer the light is split into two components which travel through the legs of the interferometer cavity and are then recombined. When the light recombines, an interference pattern is created which can range from dark (destructive interference) to bright (constructive interference). When the target moves, the reflected laser light experiences a frequency shift (increase) with respect to the frequency from the target in a static condition. Since the Doppler shifted light is split and routed through an unequal leg interferometer cavity, there is a time lag of the light containing the Doppler information at the recombination point in the interferometer. The effect of the time lag is to create a sinusoidally changing interference pattern (commonly called fringes). Since the interferometer time delay, laser wavelength, and the speed of light are known, an accurate measurement of target velocity/acceleration may be measured by analyzing both the number of tinges and the speed of tinge generation (system accuracy is 3--4%).

  13. Studies of Plutonium-238 Production at the High Flux Isotope Reactor

    SciTech Connect (OSTI)

    Lastres, Oscar; Chandler, David; Jarrell, Joshua J; Maldonado, G. Ivan

    2011-01-01

    The High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) is a versatile 85 MW{sub th}, pressurized, light water-cooled and -moderated research reactor. The core consists of two fuel elements, an inner fuel element (IFE) and an outer fuel element (OFE), each constructed of involute fuel plates containing high-enriched-uranium (HEU) fuel ({approx}93 wt% {sup 235}U/U) in the form of U{sub 3}O{sub 8} in an Al matrix and encapsulated in Al-6061 clad. An over-moderated flux trap is located in the center of the core, a large beryllium reflector is located on the outside of the core, and two control elements (CE) are located between the fuel and the reflector. The flux trap and reflector house numerous experimental facilities which are used for isotope production, material irradiation, and cold/thermal neutron scattering. Over the past five decades, the US Department of Energy (DOE) and its agencies have been producing radioisotope power systems used by the National Aeronautics and Space Administration (NASA) for unmanned, long-term space exploration missions. Plutonium-238 is used to power Radioisotope Thermoelectric Generators (RTG) because it has a very long half-life (t{sub 1/2} {approx} 89 yr.) and it generates about 0.5 watts/gram when it decays via alpha emission. Due to the recent shortage and uncertainty of future production, the DOE has proposed a plan to the US Congress to produce {sup 238}Pu by irradiating {sup 237}Np as early as in fiscal year 2011. An annual production rate of 1.5 to 2.0 kg of {sup 238}Pu is expected to satisfy these needs and could be produced in existing national nuclear facilities like HFIR and the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). Reactors at the Savannah River Site were used in the past for {sup 238}Pu production but were shut down after the last production in 1988. The nation's {sup 237}Np inventory is currently stored at INL. A plan for producing {sup 238}Pu at US research reactor

  14. Experimental and Analytic Study on the Core Bypass Flow in a Very High Temperature Reactor

    SciTech Connect (OSTI)

    Richard Schultz

    2012-04-01

    Core bypass flow has been one of key issues in the very high temperature reactor (VHTR) design for securing core thermal margins and achieving target temperatures at the core exit. The bypass flow in a prismatic VHTR core occurs through the control element holes and the radial and axial gaps between the graphite blocks for manufacturing and refueling tolerances. These gaps vary with the core life cycles because of the irradiation swelling/shrinkage characteristic of the graphite blocks such as fuel and reflector blocks, which are main components of a core's structure. Thus, the core bypass flow occurs in a complicated multidimensional way. The accurate prediction of this bypass flow and counter-measures to minimize it are thus of major importance in assuring core thermal margins and securing higher core efficiency. Even with this importance, there has not been much effort in quantifying and accurately modeling the effect of the core bypass flow. The main objectives of this project were to generate experimental data for validating the software to be used to calculate the bypass flow in a prismatic VHTR core, validate thermofluid analysis tools and their model improvements, and identify and assess measures for reducing the bypass flow. To achieve these objectives, tasks were defined to (1) design and construct experiments to generate validation data for software analysis tools, (2) determine the experimental conditions and define the measurement requirements and techniques, (3) generate and analyze the experimental data, (4) validate and improve the thermofluid analysis tools, and (5) identify measures to control the bypass flow and assess its performance in the experiment.

  15. Updated flux information for neutron scattering and irradiation facilities at the BNL High Flux Beam Reactor

    SciTech Connect (OSTI)

    Holden, N.E.; Hu, J.P.; Reciniello, R.N.; Sengupta, S.; Greenwood, L.R.; Farrell, K.

    1997-08-01

    The HFBR is a heavy water, D{sub 2}O, cooled and moderated reactor with twenty-eight fuel elements containing a maximum of 9.8 kilograms of {sup 235}U. While most reactors attempt to minimize the escape of neutrons from the core, the HFBR`s D{sub 2}O design allows the thermal neutron flux to peak in the reflector region and maximizes the number of thermal neutrons available to nine horizontal external beams, H-1 to H-9, used for neutron scattering and capture reactions, supporting physics, chemistry and biology experiments. All horizontal beam tubes were built tangential to the direction of the emerging neutrons, except for the H-2 beam tube, which looks directly at the core and has been used for neutron cross section measurements utilizing fast neutrons and for the TRISTAN fission product studies. In recent years, there have been some beam modifications and new instrumentation introduced at the HFBR. A high resolution neutron powder diffractometer instrument is now operating with a resolution of 5 {times} 10{sup {minus}4} at horizontal beam line H-1. To study scattering from liquid surfaces, a neutron reflection spectrometer was introduced on the CNF beam line at H-9. In the past year, a fourth beam line has been added to the CNF line at H-9. The existing beam plug at the H-6 beam line has recently been removed and a new plug, which will feature super mirrored surfaces, is now being installed. Last year, the vertical beam thimble, V-13, a fixed port filled with thirty year old samples used for HFBR material surveillance studies was replaced by a new thimble and charging station at the core edge creating an irradiation facility to substitute for the original V-13. A neutron dosimetry program has begun to measure and calculate the energy dependent neutron and gamma ray flux densities and/or dose rates at horizontal beam lines and vertical irradiation thimbles.

  16. High efficiency and high concentration in photovoltaics

    SciTech Connect (OSTI)

    Yamaguchi, Masafumi; Luque, A.

    1999-10-01

    In this paper, the authors present the state-of-the-art of multijunction solar cells and the future prospects of this technology. Their use in terrestrial applications will likely be for concentrators operating at very high concentrations. Some trends are also discussed and the authors present a cost calculation showing that highly efficient cells under very high concentration would be able to produce electricity at costs competitive with electricity generation costs for some utilities.

  17. Highly Enriched Uranyl Nitrate in Annular Tanks with Concrete Reflection: 1 x 3 Line Array of Nested Pairs of Tanks

    SciTech Connect (OSTI)

    James Cleaver; John D. Bess; Nathan Devine; Fitz Trumble

    2009-09-01

    A series of seven experiments were performed at the Rocky Flats Critical Mass Laboratory beginning in August, 1980 (References 1 and 2). Highly enriched uranyl nitrate solution was introduced into a 1-3 linear array of nested stainless steel annular tanks. The tanks were inside a concrete enclosure, with various moderator and absorber materials placed inside and/or between the tanks. These moderators and absorbers included boron-free concrete, borated concrete, borated plaster, and cadmium. Two configurations included placing bottles of highly enriched uranyl nitrate between tanks externally. Another experiment involved nested hemispheres of highly enriched uranium placed between tanks externally. These three configurations are not evaluated in this report. The experiments evaluated here are part of a series of experiments, one set of which is evaluated in HEU-SOL-THERM-033. The experiments in this and HEU-SOL-THERM-033 were performed similarly. They took place in the same room and used the same tanks, some of the same moderators and absorbers, some of the same reflector panels, and uranyl nitrate solution from the same location. There are probably additional similarities that existed that are not identified here. Thus, many of the descriptions in this report are either the same or similar to those in the HEU-SOL-THERM-033 report. Seventeen configurations (sixteen of which were critical) were performed during seven experiments; six of those experiments are evaluated here with thirteen configurations. Two configurations were identical, except for solution height, and were conducted to test repeatability. The solution heights were averaged and the two were evaluated as one configuration, which gives a total of twelve evaluated configurations. One of the seventeen configurations was subcritical. Of the twelve critical configurations evaluated, nine were judged as acceptable as benchmarks.

  18. High Efficiency Triple-Junction Amorphous Silicon Alloy Photovoltaic Technology, Final Technical Report, 6 March 1998 - 15 October 2001

    SciTech Connect (OSTI)

    Guha, S.

    2001-11-08

    This report describes the research program intended to expand, enhance, and accelerate knowledge and capabilities for developing high-performance, two-terminal multijunction amorphous silicon (a-Si) alloy cells, and modules with low manufacturing cost and high reliability. United Solar uses a spectrum-splitting, triple-junction cell structure. The top cell uses an amorphous silicon alloy of {approx}1.8-eV bandgap to absorb blue photons. The middle cell uses an amorphous silicon germanium alloy ({approx}20% germanium) of {approx}1.6-eV bandgap to capture green photons. The bottom cell has {approx}40% germanium to reduce the bandgap to {approx}1.4-eV to capture red photons. The cells are deposited on a stainless-steel substrate with a predeposited silver/zinc oxide back reflector to facilitate light-trapping. A thin layer of antireflection coating is applied to the top of the cell to reduce reflection loss. The major research activities conducted under this program were: (1) Fundamental studies to improve our understanding of materials and devices; the work included developing and analyzing a-Si alloy and a-SiGe alloy materials prepared near the threshold of amorphous-to-microcrystalline transition and studying solar cells fabricated using these materials. (2) Deposition of small-area cells using a radio-frequency technique to obtain higher deposition rates. (3) Deposition of small-area cells using a modified very high frequency technique to obtain higher deposition rates. (4) Large-area cell research to obtain the highest module efficiency. (5) Optimization of solar cells and modules fabricated using production parameters in a large-area reactor.

  19. High Performance Computing

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

    HPC INL Logo Home High-Performance Computing INL's high-performance computing center provides general use scientific computing capabilities to support the lab's efforts in advanced...

  20. High pressure, high current, low inductance, high reliability sealed terminals

    DOE Patents [OSTI]

    Hsu, John S [Oak Ridge, TN; McKeever, John W [Oak Ridge, TN

    2010-03-23

    The invention is a terminal assembly having a casing with at least one delivery tapered-cone conductor and at least one return tapered-cone conductor routed there-through. The delivery and return tapered-cone conductors are electrically isolated from each other and positioned in the annuluses of ordered concentric cones at an off-normal angle. The tapered cone conductor service can be AC phase conductors and DC link conductors. The center core has at least one service conduit of gate signal leads, diagnostic signal wires, and refrigerant tubing routed there-through. A seal material is in direct contact with the casing inner surface, the tapered-cone conductors, and the service conduits thereby hermetically filling the interstitial space in the casing interior core and center core. The assembly provides simultaneous high-current, high-pressure, low-inductance, and high-reliability service.

  1. High strength and high toughness steel

    DOE Patents [OSTI]

    Parker, Earl R.; Zackay, Victor F.

    1979-01-01

    A structural steel which possess both high strength and high toughness and has particular application of cryogenic uses. The steel is produced by the utilization of thermally induced phase transformation following heating in a three-phase field in iron-rich alloys of the Fe-Ni-Ti system, with a preferred composition of 12% nickel, 0.5% titanium, the remainder being iron.

  2. High strength, high ductility low carbon steel

    DOE Patents [OSTI]

    Koo, Jayoung; Thomas, Gareth

    1978-01-01

    A high strength, high ductility low carbon steel consisting essentially of iron, 0.05-0.15 wt% carbon, and 1-3 wt% silicon. Minor amounts of other constituents may be present. The steel is characterized by a duplex ferrite-martensite microstructure in a fibrous morphology. The microstructure is developed by heat treatment consisting of initial austenitizing treatment followed by annealing in the (.alpha. + .gamma.) range with intermediate quenching.

  3. Design Study for a Low-Enriched Uranium Core for the High Flux Isotope Reactor, Annual Report for FY 2006

    SciTech Connect (OSTI)

    Primm, R. T.; Ellis, R. J.; Gehin, J. C.; Clarno, K. T.; Williams, K. A.; Moses, D. L.

    2006-11-01

    Neutronics and thermal-hydraulics studies show that, for equivalent operating power [85 MW(t)], a low-enriched uranium (LEU) fuel cycle based on uranium-10 wt % molybdenum (U-10Mo) metal foil with radially, continuously graded fuel meat thickness results in a 15% reduction in peak thermal flux in the beryllium reflector of the High Flux Isotope Reactor (HFIR) as compared to the current highly enriched uranium (HEU) cycle. The uranium-235 content of the LEU core is almost twice the amount of the HEU core when the length of the fuel cycle is kept the same for both fuels. Because the uranium-238 content of an LEU core is a factor of 4 greater than the uranium-235 content, the LEU HFIR core would weigh 30% more than the HEU core. A minimum U-10Mo foil thickness of 84 ?m is required to compensate for power peaking in the LEU core although this value could be increased significantly without much penalty. The maximum U-10Mo foil thickness is 457?m. Annual plutonium production from fueling the HFIR with LEU is predicted to be 2 kg. For dispersion fuels, the operating power for HFIR would be reduced considerably below 85 MW due to thermal considerations and due to the requirement of a 26-d fuel cycle. If an acceptable fuel can be developed, it is estimated that $140 M would be required to implement the conversion of the HFIR site at Oak Ridge National Laboratory from an HEU fuel cycle to an LEU fuel cycle. To complete the conversion by fiscal year 2014 would require that all fuel development and qualification be completed by the end of fiscal year 2009. Technological development areas that could increase the operating power of HFIR are identified as areas for study in the future.

  4. High School Internship Program

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

    High School Internship Program High School Internship Program Point your career towards Los Alamos Lab: work with the best minds on the planet in an inclusive environment that is rich in intellectual vitality and opportunities for growth. Contact Program Manager Scott Robbins Student Programs (505) 667-3639 Email Program Coordinator Brenda Montoya Student Programs (505) 667-4866 Email Opportunities for Northern New Mexico high school seniors The High School Internship Program provides qualified

  5. High power microwave generator

    DOE Patents [OSTI]

    Ekdahl, Carl A.

    1986-01-01

    A microwave generator efficiently converts the energy of an intense relativistic electron beam (REB) into a high-power microwave emission using the Smith-Purcell effect which is related to Cerenkov radiation. Feedback for efficient beam bunching and high gain is obtained by placing a cylindrical Smith-Purcell transmission grating on the axis of a toroidal resonator. High efficiency results from the use of a thin cold annular highly-magnetized REB that is closely coupled to the resonant structure.

  6. High power microwave generator

    DOE Patents [OSTI]

    Ekdahl, C.A.

    1983-12-29

    A microwave generator efficiently converts the energy of an intense relativistic electron beam (REB) into a high-power microwave emission using the Smith-Purcell effect which is related to Cerenkov radiation. Feedback for efficient beam bunching and high gain is obtained by placing a cylindrical Smith-Purcell transmission grating on the axis of a toroidal resonator. High efficiency results from the use of a thin cold annular highly-magnetized REB that is closely coupled to the resonant structure.

  7. High Explosives Testing

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

    Administration | (NNSA) High Explosives Application Facility A Livermore scientist uses a laser spectroscopic method with a diamond anvil DOE/NNSA has identified LLNL's High Explosives Applications Facility (HEAF) as the complex-wide "Center of Excellence" for High-Explosives Research and Development. In this capacity, HEAF is a source of subject matter expertise for high explosives and other energetic materials. Its mission is to provide this expertise to serve multiple government

  8. High performance systems

    SciTech Connect (OSTI)

    Vigil, M.B.

    1995-03-01

    This document provides a written compilation of the presentations and viewgraphs from the 1994 Conference on High Speed Computing given at the High Speed Computing Conference, {open_quotes}High Performance Systems,{close_quotes} held at Gleneden Beach, Oregon, on April 18 through 21, 1994.

  9. High power, high beam quality regenerative amplifier

    DOE Patents [OSTI]

    Hackel, L.A.; Dane, C.B.

    1993-08-24

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  10. High power, high beam quality regenerative amplifier

    DOE Patents [OSTI]

    Hackel, Lloyd A.; Dane, Clifford B.

    1993-01-01

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  11. High Tech Halloween

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

    High Tech Halloween High Tech Halloween WHEN: Oct 30, 2015 4:00 PM - 6:30 PM WHERE: Bradbury Science Museum 1350 Central Avenue, Los Alamos, New Mexico, 87544 USA CONTACT: Linda Anderman (505) 665-9196 CATEGORY: Bradbury INTERNAL: Calendar Login High Tech Halloween Event Description High-Tech Halloween is the Bradbury Science Museum's contribution to Downtown Los Alamos' annual Trick-or-Treat on MainStreet event taking place the Friday before Halloween. At this year's High-Tech Halloween, you

  12. Low Cost, High Temperature, High Ripple Current DC Bus Capacitors...

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

    Low Cost, High Temperature, High Ripple Current DC Bus Capacitors Low Cost, High Temperature, High Ripple Current DC Bus Capacitors 2010 DOE Vehicle Technologies and Hydrogen...

  13. FULLY INTEGRATED HIGH SPEED MEGAWATT CLASS MOTOR AND HIGH FREQUENCY...

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

    FULLY INTEGRATED HIGH SPEED MEGAWATT CLASS MOTOR AND HIGH FREQUENCY VARIABLE SPEED DRIVE SYSTEM FULLY INTEGRATED HIGH SPEED MEGAWATT CLASS MOTOR AND HIGH FREQUENCY VARIABLE SPEED ...

  14. High-pressure, high-temperature plastic deformation of sintered...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: High-pressure, high-temperature plastic deformation of sintered diamonds Citation Details In-Document Search Title: High-pressure, high-temperature plastic ...

  15. High pressure and high temperature apparatus

    DOE Patents [OSTI]

    Voronov, Oleg A.

    2005-09-13

    A design for high pressure/high temperature apparatus and reaction cell to achieve .about.30 GPa pressure in .about.1 cm volume and .about.100 GPa pressure in .about.1 mm volumes and 20-5000.degree. C. temperatures in a static regime. The device includes profiled anvils (28) action on a reaction cell (14, 16) containing the material (26) to be processed. The reaction cell includes a heater (18) surrounded by insulating layers and screens. Surrounding the anvils are cylindrical inserts and supporting rings (30-48) whose hardness increases towards the reaction cell. These volumes may be increased considerably if applications require it, making use of presses that have larger loading force capability, larger frames and using larger anvils.

  16. HIGH VOLTAGE, HIGH CURRENT SPARK GAP SWITCH

    DOE Patents [OSTI]

    Dike, R.S.; Lier, D.W.; Schofield, A.E.; Tuck, J.L.

    1962-04-17

    A high voltage and current spark gap switch comprising two main electrodes insulatingly supported in opposed spaced relationship and a middle electrode supported medially between the main electrodes and symmetrically about the median line of the main electrodes is described. The middle electrode has a perforation aligned with the median line and an irradiation electrode insulatingly supported in the body of the middle electrode normal to the median line and protruding into the perforation. (AEC)

  17. High output lamp with high brightness

    DOE Patents [OSTI]

    Kirkpatrick, Douglas A.; Bass, Gary K.; Copsey, Jesse F.; Garber, Jr., William E.; Kwong, Vincent H.; Levin, Izrail; MacLennan, Donald A.; Roy, Robert J.; Steiner, Paul E.; Tsai, Peter; Turner, Brian P.

    2002-01-01

    An ultra bright, low wattage inductively coupled electrodeless aperture lamp is powered by a solid state RF source in the range of several tens to several hundreds of watts at various frequencies in the range of 400 to 900 MHz. Numerous novel lamp circuits and components are disclosed including a wedding ring shaped coil having one axial and one radial lead, a high accuracy capacitor stack, a high thermal conductivity aperture cup and various other aperture bulb configurations, a coaxial capacitor arrangement, and an integrated coil and capacitor assembly. Numerous novel RF circuits are also disclosed including a high power oscillator circuit with reduced complexity resonant pole configuration, parallel RF power FET transistors with soft gate switching, a continuously variable frequency tuning circuit, a six port directional coupler, an impedance switching RF source, and an RF source with controlled frequency-load characteristics. Numerous novel RF control methods are disclosed including controlled adjustment of the operating frequency to find a resonant frequency and reduce reflected RF power, controlled switching of an impedance switched lamp system, active power control and active gate bias control.

  18. High voltage coaxial switch

    DOE Patents [OSTI]

    Rink, John P.

    1983-07-19

    A coaxial high voltage, high current switch having a solid cylindrical cold cathode coaxially surrounded by a thin hollow cylindrical inner electrode and a larger hollow cylindrical outer electrode. A high voltage trigger between the cathode and the inner electrode causes electrons to be emitted from the cathode and flow to the inner electrode preferably through a vacuum. Some of the electrons penetrate the inner electrode and cause a volumetric discharge in the gas (which may be merely air) between the inner and outer electrodes. The discharge provides a low impedance path between a high voltage charge placed on the outer electrode and a load (which may be a high power laser) coupled to the inner electrode. For high repetition rate the gas between the inner and outer electrodes may be continuously exchanged or refreshed under pressure.

  19. High voltage coaxial switch

    DOE Patents [OSTI]

    Rink, J.P.

    1983-07-19

    A coaxial high voltage, high current switch having a solid cylindrical cold cathode coaxially surrounded by a thin hollow cylindrical inner electrode and a larger hollow cylindrical outer electrode. A high voltage trigger between the cathode and the inner electrode causes electrons to be emitted from the cathode and flow to the inner electrode preferably through a vacuum. Some of the electrons penetrate the inner electrode and cause a volumetric discharge in the gas (which may be merely air) between the inner and outer electrodes. The discharge provides a low impedance path between a high voltage charge placed on the outer electrode and a load (which may be a high power laser) coupled to the inner electrode. For high repetition rate the gas between the inner and outer electrodes may be continuously exchanged or refreshed under pressure. 3 figs.

  20. Highly directional thermal emitter

    DOE Patents [OSTI]

    Ribaudo, Troy; Shaner, Eric A; Davids, Paul; Peters, David W

    2015-03-24

    A highly directional thermal emitter device comprises a two-dimensional periodic array of heavily doped semiconductor structures on a surface of a substrate. The array provides a highly directional thermal emission at a peak wavelength between 3 and 15 microns when the array is heated. For example, highly doped silicon (HDSi) with a plasma frequency in the mid-wave infrared was used to fabricate nearly perfect absorbing two-dimensional gratings structures that function as highly directional thermal radiators. The absorption and emission characteristics of the HDSi devices possessed a high degree of angular dependence for infrared absorption in the 10-12 micron range, while maintaining high reflectivity of solar radiation (.about.64%) at large incidence angles.

  1. High temperature refrigerator

    DOE Patents [OSTI]

    Steyert, Jr., William A.

    1978-01-01

    A high temperature magnetic refrigerator which uses a Stirling-like cycle in which rotating magnetic working material is heated in zero field and adiabatically magnetized, cooled in high field, then adiabatically demagnetized. During this cycle said working material is in heat exchange with a pumped fluid which absorbs heat from a low temperature heat source and deposits heat in a high temperature reservoir. The magnetic refrigeration cycle operates at an efficiency 70% of Carnot.

  2. High temperature furnace

    DOE Patents [OSTI]

    Borkowski, Casimer J.

    1976-08-03

    A high temperature furnace for use above 2000.degree.C is provided that features fast initial heating and low power consumption at the operating temperature. The cathode is initially heated by joule heating followed by electron emission heating at the operating temperature. The cathode is designed for routine large temperature excursions without being subjected to high thermal stresses. A further characteristic of the device is the elimination of any ceramic components from the high temperature zone of the furnace.

  3. High Performance Sustainable Buildings

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

    science and bioscience capabiities. Occupational Medicine will become a High Performance Sustainable Building in 2013. On the former County landfill, a photovoltaic array field...

  4. high renewable energy penetration

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

    high renewable energy penetration - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future ...

  5. high-power LEDs

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

    ... Cost The high-brightness, rapidly pulsed, multicolor light-emitting diode (LED) driver delivers lighting performance that exceeds that of conventional (laserarc-light) sources ...

  6. High School Science Bowl

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

    High School Science Bowl High School Science Bowl WHEN: Feb 07, 2015 8:00 AM - 4:00 PM WHERE: Highland High School 4700 Coal Ave SE, Albuquerque, USA CATEGORY: Community INTERNAL: Calendar Login Event Description The Science Bowl is a Jeopardy-like event for high school and middle school students who have a strong interest in mathematics and science. The competition is in the form of a round robin in the morning and double elimination after lunch. Teams consist of four students and one optional

  7. High power, high frequency, vacuum flange

    DOE Patents [OSTI]

    Felker, Brian (Livermore, CA); McDaniel, Michael R. (Manteca, CA)

    1993-01-01

    An improved waveguide flange is disclosed for high power operation that helps prevent arcs from being initiated at the junctions between waveguide sections. The flanges at the end of the waveguide sections have counterbores surrounding the waveguide tubes. When the sections are bolted together the counterbores form a groove that holds a fully annealed copper gasket. Each counterbore has a beveled step that is specially configured to insure the gasket forms a metal-to-metal vacuum seal without gaps or sharp edges. The resultant inner surface of the waveguide is smooth across the junctions between waveguide sections, and arcing is prevented.

  8. High power, high frequency, vacuum flange

    DOE Patents [OSTI]

    Felker, B.; McDaniel, M.R.

    1993-03-23

    An improved waveguide flange is disclosed for high power operation that helps prevent arcs from being initiated at the junctions between waveguide sections. The flanges at the end of the waveguide sections have counter bores surrounding the waveguide tubes. When the sections are bolted together the counter bores form a groove that holds a fully annealed copper gasket. Each counterbore has a beveled step that is specially configured to insure the gasket forms a metal-to-metal vacuum seal without gaps or sharp edges. The resultant inner surface of the waveguide is smooth across the junctions between waveguide sections, and arcing is prevented.

  9. Towards high efficiency thin-film crystalline silicon solar cells: The roles of light trapping and non-radiative recombinations

    SciTech Connect (OSTI)

    Bozzola, A. Kowalczewski, P.; Andreani, L. C.

    2014-03-07

    Thin-film solar cells based on silicon have emerged as an alternative to standard thick wafers technology, but they are less efficient, because of incomplete absorption of sunlight, and non-radiative recombinations. In this paper, we focus on the case of crystalline silicon (c-Si) devices, and we present a full analytic electro-optical model for p-n junction solar cells with Lambertian light trapping. This model is validated against numerical solutions of the drift-diffusion equations. We use this model to investigate the interplay between light trapping, and bulk and surface recombination. Special attention is paid to surface recombination processes, which become more important in thinner devices. These effects are further amplified due to the textures required for light trapping, which lead to increased surface area. We show that c-Si solar cells with thickness of a few microns can overcome 20% efficiency and outperform bulk ones when light trapping is implemented. The optimal device thickness in presence of light trapping, bulk and surface recombination, is quantified to be in the range of 1080??m, depending on the bulk quality. These results hold, provided the effective surface recombination is kept below a critical level of the order of 100?cm/s. We discuss the possibility of meeting this requirement, in the context of state-of-the-art techniques for light trapping and surface passivation. We show that our predictions are within the capability of present day silicon technologies.

  10. ZPR-3 Assembly 6F : A spherical assembly of highly enriched uranium, depleted uranium, aluminum and steel with an average {sup 235}U enrichment of 47 atom %.

    SciTech Connect (OSTI)

    Lell, R. M.; McKnight, R. D; Schaefer, R. W.; Nuclear Engineering Division

    2010-09-30

    Assembly 6F (ZPR-3/6F), the final phase of the Assembly 6 program, simulated a spherical core with a thick depleted uranium reflector. ZPR-3/6F was designed as a fast reactor physics benchmark experiment with an average core {sup 235}U enrichment of approximately 47 at.%. Approximately 81.4% of the total fissions in this assembly occur above 100 keV, approximately 18.6% occur below 100 keV, and essentially none below 0.625 eV - thus the classification as a 'fast' assembly. This assembly is Fast Reactor Benchmark No. 7 in the Cross Section Evaluation Working Group (CSEWG) Benchmark Specifications and has historically been used as a data validation benchmark assembly. Loading of ZPR-3/6F began in late December 1956, and the experimental measurements were performed in January 1957. The core consisted of highly enriched uranium (HEU) plates, depleted uranium plates, perforated aluminum plates and stainless steel plates loaded into aluminum drawers, which were inserted into the central square stainless steel tubes of a 31 x 31 matrix on a split table machine. The core unit cell consisted of three columns of 0.125 in.-wide (3.175 mm) HEU plates, three columns of 0.125 in.-wide depleted uranium plates, nine columns of 0.125 in.-wide perforated aluminum plates and one column of stainless steel plates. The maximum length of each column of core material in a drawer was 9 in. (228.6 mm). Because of the goal to produce an approximately spherical core, core fuel and diluent column lengths generally varied between adjacent drawers and frequently within an individual drawer. The axial reflector consisted of depleted uranium plates and blocks loaded in the available space in the front (core) drawers, with the remainder loaded into back drawers behind the front drawers. The radial reflector consisted of blocks of depleted uranium loaded directly into the matrix tubes. The assembly geometry approximated a reflected sphere as closely as the square matrix tubes, the drawers and the shapes of

  11. High density photovoltaic

    SciTech Connect (OSTI)

    Haigh, R.E.; Jacobson, G.F.; Wojtczuk, S.

    1997-10-14

    Photovoltaic technology can directly generate high voltages in a solid state material through the series interconnect of many photovoltaic diodes. We are investigating the feasibility of developing an electrically isolated, high-voltage power supply using miniature photovoltaic devices that convert optical energy to electrical energy.

  12. High coking value pitch

    SciTech Connect (OSTI)

    Miller, Douglas J.; Chang, Ching-Feng; Lewis, Irwin C.; Lewis, Richard T.

    2014-06-10

    A high coking value pitch prepared from coal tar distillate and has a low softening point and a high carbon value while containing substantially no quinoline insolubles is disclosed. The pitch can be used as an impregnant or binder for producing carbon and graphite articles.

  13. High temperature sensor

    DOE Patents [OSTI]

    Tokarz, Richard D.

    1982-01-01

    A high temperature sensor includes a pair of electrical conductors separated by a mass of electrical insulating material. The insulating material has a measurable resistivity within the sensor that changes in relation to the temperature of the insulating material within a high temperature range (1,000 to 2,000 K.). When required, the sensor can be encased within a ceramic protective coating.

  14. RF/optical shared aperture for high availability wideband communication RF/FSO links

    DOE Patents [OSTI]

    Ruggiero, Anthony J; Pao, Hsueh-yuan; Sargis, Paul

    2015-03-24

    An RF/Optical shared aperture is capable of transmitting and receiving optical signals and RF signals simultaneously. This technology enables compact wide bandwidth communications systems with 100% availability in clear air turbulence, rain and fog. The functions of an optical telescope and an RF reflector antenna are combined into a single compact package by installing an RF feed at either of the focal points of a modified Gregorian telescope.

  15. RF/optical shared aperture for high availability wideband communication RF/FSO links

    DOE Patents [OSTI]

    Ruggiero, Anthony J; Pao, Hsueh-yuan; Sargis, Paul

    2014-04-29

    An RF/Optical shared aperture is capable of transmitting and receiving optical signals and RF signals simultaneously. This technology enables compact wide bandwidth communications systems with 100% availability in clear air turbulence, rain and fog. The functions of an optical telescope and an RF reflector antenna are combined into a single compact package by installing an RF feed at either of the focal points of a modified Gregorian telescope.

  16. High pressure oxygen furnace

    DOE Patents [OSTI]

    Morris, D.E.

    1992-07-14

    A high temperature high pressure oxygen furnace having a hybrid partially externally heated construction is disclosed. A metallic bar fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized, the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 inch bar stock and has a length of about 17 inches. This bar stock is gun drilled for over 16 inches of its length with 0.400 inch aperture to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the bar is provided with a small support aperture into which both a support and a thermocouple can be inserted. The closed end of the gun drilled bar is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior. 5 figs.

  17. High pressure oxygen furnace

    DOE Patents [OSTI]

    Morris, Donald E.

    1992-01-01

    A high temperature high pressure oxygen furnace having a hybrid partially externally heated construction is disclosed. A metallic bar fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 inch bar stock and has a length of about 17 inches. This bar stock is gun drilled for over 16 inches of its length with 0.400 inch aperture to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the bar is provided with a small support aperture into which both a support and a thermocouple can be inserted. The closed end of the gun drilled bar is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior.

  18. High-Speed Photography

    SciTech Connect (OSTI)

    Paisley, D.L.; Schelev, M.Y.

    1998-08-01

    The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) {copyright} {ital 1998 Society of Photo-Optical Instrumentation Engineers.}

  19. High-Temperature Superconductivity

    ScienceCinema (OSTI)

    Peter Johnson

    2010-01-08

    Like astronomers tweaking images to gain a more detailed glimpse of distant stars, physicists at Brookhaven National Laboratory have found ways to sharpen images of the energy spectra in high-temperature superconductors ? materials that carry electrical c

  20. High pressure furnace

    DOE Patents [OSTI]

    Morris, D.E.

    1993-09-14

    A high temperature high pressure furnace has a hybrid partially externally heated construction. A metallic vessel fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum)). The disclosed alloy is fabricated into 11/4 or 2 inch, 32 mm or 50 mm bar stock and has a length of about 22 inches, 56 cm. This bar stock has an aperture formed therein to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the vessel is provided with a small blind aperture into which a thermocouple can be inserted. The closed end of the vessel is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior. 19 figures.

  1. High pressure furnace

    DOE Patents [OSTI]

    Morris, Donald E.

    1993-01-01

    A high temperature high pressure furnace has a hybrid partially externally heated construction. A metallic vessel fabricated from an alloy having a composition of at least 45% nickel, 15% chrome, and 10% tungsten is utilized (the preferred alloy including 55% nickel, 22% chrome, 14% tungsten, 2% molybdenum, 3% iron (maximum) and 5% cobalt (maximum). The disclosed alloy is fabricated into 11/4 or 2 inch, 32 mm or 50 mm bar stock and has a length of about 22 inches, 56 cm. This bar stock has an aperture formed therein to define a closed high temperature, high pressure oxygen chamber. The opposite and closed end of the vessel is provided with a small blind aperture into which a thermocouple can be inserted. The closed end of the vessel is inserted into an oven, preferably heated by standard nickel chrome electrical elements and having a heavily insulated exterior.

  2. High Performance Sustainable Building

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2011-11-09

    This Guide provides approaches for implementing the High Performance Sustainable Building (HPSB) requirements of DOE Order 413.3B, Program and Project Management for the Acquisition of Capital Assets. Supersedes DOE G 413.3-6.

  3. High Performance Sustainable Building

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2011-11-09

    This Guide highlights the DOE O 413.3B drivers for incorporating high performance sustainable building (HPSB) principles into Critical Decisions 1 through 4 and provides guidance for implementing the Order's HPSB requirements.

  4. High conductivity composite metal

    DOE Patents [OSTI]

    Zhou, Ruoyi; Smith, James L.; Embury, John David

    1998-01-01

    Electrical conductors and methods of producing them, where the conductors possess both high strength and high conductivity. Conductors are comprised of carbon steel and a material chosen from a group consisting of copper, nickel, silver, and gold. Diffusion barriers are placed between these two materials. The components of a conductor are assembled and then the assembly is subjected to heat treating and mechanical deformation steps.

  5. High conductivity composite metal

    DOE Patents [OSTI]

    Zhou, R.; Smith, J.L.; Embury, J.D.

    1998-01-06

    Electrical conductors and methods of producing them are disclosed, where the conductors possess both high strength and high conductivity. Conductors are comprised of carbon steel and a material chosen from a group consisting of copper, nickel, silver, and gold. Diffusion barriers are placed between these two materials. The components of a conductor are assembled and then the assembly is subjected to heat treating and mechanical deformation steps. 10 figs.

  6. High Energy Physics

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

    Administration | (NNSA) High Energy Density Laboratory Plasmas Program Steady advances in increasing the energy, power, and brightness of lasers and particle beams and advances in pulsed power systems have made possible the exploration of matter at extremely high energy density in the laboratory. Exciting new experimental regimes are being realized by exploiting the scientific capabilities of existing ICF Office facilities, as well as the relevant Department of Defense (DoD) and university

  7. High Performance Sustainable Buildings

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

    Buildings Goal 3: High Performance Sustainable Buildings Maintaining the conditions of a building improves the health of not only the surrounding ecosystems, but also the well-being of its occupants. Energy Conservation» Efficient Water Use & Management» High Performance Sustainable Buildings» Greening Transportation» Green Purchasing & Green Technology» Pollution Prevention» Science Serving Sustainability» ENVIRONMENTAL SUSTAINABILITY GOALS at LANL The Radiological Laboratory

  8. High temperature pressure gauge

    DOE Patents [OSTI]

    Echtler, J. Paul; Scandrol, Roy O.

    1981-01-01

    A high temperature pressure gauge comprising a pressure gauge positioned in fluid communication with one end of a conduit which has a diaphragm mounted in its other end. The conduit is filled with a low melting metal alloy above the diaphragm for a portion of its length with a high temperature fluid being positioned in the remaining length of the conduit and in the pressure gauge.

  9. HIGH TEMPERATURE THERMOCOUPLE

    DOE Patents [OSTI]

    Eshayu, A.M.

    1963-02-12

    This invention contemplates a high temperature thermocouple for use in an inert or a reducing atmosphere. The thermocouple limbs are made of rhenium and graphite and these limbs are connected at their hot ends in compressed removable contact. The rhenium and graphite are of high purity and are substantially stable and free from diffusion into each other even without shielding. Also, the graphite may be thick enough to support the thermocouple in a gas stream. (AEC)

  10. High efficiency incandescent lighting

    DOE Patents [OSTI]

    Bermel, Peter; Ilic, Ognjen; Chan, Walker R.; Musabeyoglu, Ahmet; Cukierman, Aviv Ruben; Harradon, Michael Robert; Celanovic, Ivan; Soljacic, Marin

    2014-09-02

    Incandescent lighting structure. The structure includes a thermal emitter that can, but does not have to, include a first photonic crystal on its surface to tailor thermal emission coupled to, in a high-view-factor geometry, a second photonic filter selected to reflect infrared radiation back to the emitter while passing visible light. This structure is highly efficient as compared to standard incandescent light bulbs.