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Sample records for high-efficiency fusion power

  1. High-Efficiency Power Module

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N. (Inventor); Wintucky, Edwin G. (Inventor)

    2015-01-01

    One or more embodiments of the present invention pertain to an all solid-state microwave power module. The module includes a plurality of solid-state amplifiers configured to amplify a signal using a low power stage, a medium power stage, and a high power stage. The module also includes a power conditioner configured to activate a voltage sequencer (e.g., bias controller) when power is received from a power source. The voltage sequencer is configured to sequentially apply voltage to a gate of each amplifier and sequentially apply voltage to a drain of each amplifier.

  2. High-Efficiency Power Module

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N (Inventor); Wintucky, Edwin G (Inventor)

    2013-01-01

    One or more embodiments of the present invention pertain to an all solid-state microwave power module. The module includes a plurality of solid-state amplifiers configured to amplify a signal using a low power stage, a medium power stage, and a high power stage. The module also includes a power conditioner configured to activate a voltage sequencer (e.g., bias controller) when power is received from a power source. The voltage sequencer is configured to sequentially apply voltage to a gate of each amplifier and sequentially apply voltage to a drain of each amplifier.

  3. High efficiency solar photovoltaic power module concept

    NASA Technical Reports Server (NTRS)

    Bekey, I.

    1978-01-01

    The investigation of a preliminary concept for high efficiency solar power generation in space is presented. The concept was a synergistic combination of spectral splitting, tailored bandgap cells, high concentration ratios, and cool cell areas.

  4. High-efficiency solid state power amplifier

    NASA Technical Reports Server (NTRS)

    Wallis, Robert E. (Inventor); Cheng, Sheng (Inventor)

    2005-01-01

    A high-efficiency solid state power amplifier (SSPA) for specific use in a spacecraft is provided. The SSPA has a mass of less than 850 g and includes two different X-band power amplifier sections, i.e., a lumped power amplifier with a single 11-W output and a distributed power amplifier with eight 2.75-W outputs. These two amplifier sections provide output power that is scalable from 11 to 15 watts without major design changes. Five different hybrid microcircuits, including high-efficiency Heterostructure Field Effect Transistor (HFET) amplifiers and Monolithic Microwave Integrated Circuit (MMIC) phase shifters have been developed for use within the SSPA. A highly efficient packaging approach enables the integration of a large number of hybrid circuits into the SSPA.

  5. High Efficiency Targets for High Gain Inertial Confinement Fusion.

    DTIC Science & Technology

    1986-09-19

    Inertial Confinement Fusion JOHN H. GARDNER AND STEPHEN E. BODNER Laboratory for Computational Physics DTIC CD ELECTEf OCT 241986 j NU Aproedfr...81425 " 11 TITLE (include Security Classification) High Efficiency Targets for High Gain Inertial Confinement Fusion 12. PERSONAL AUTHOR(S) Gardner, John ...ArearCod) 22c OFFICE SYMBOL % John H. Gardner (202) 767-3055 Code 4040 DO FORM 1473. 84 MAR 83 APR edtion may be used until exhausted SECURITY

  6. Fusion Power.

    ERIC Educational Resources Information Center

    Dingee, David A.

    1979-01-01

    Discusses the extraordinary potential, the technical difficulties, and the financial problems that are associated with research and development of fusion power plants as a major source of energy. (GA)

  7. High-power, high-efficiency FELs

    SciTech Connect

    Sessler, A.M.

    1989-04-01

    High power, high efficiency FELs require tapering, as the particles loose energy, so as to maintain resonance between the electromagnetic wave and the particles. They also require focusing of the particles (usually done with curved pole faces) and focusing of the electromagnetic wave (i.e. optical guiding). In addition, one must avoid transverse beam instabilities (primarily resistive wall) and longitudinal instabilities (i.e sidebands). 18 refs., 7 figs., 3 tabs.

  8. High Efficiency Microwave Power Amplifier (HEMPA) Design

    NASA Technical Reports Server (NTRS)

    Sims, W. Herbert

    2004-01-01

    This paper will focus on developing an exotic switching technique that enhances the DC-to-RF conversion efficiency of microwave power amplifiers. For years, switching techniques implemented in the 10 kHz to 30 MHz region have resulted in DC-to-RF conversion efficiencies of 90-95-percent. Currently amplifier conversion efficiency, in the 2-3 GHz region approaches, 10-20-percent. Using a combination of analytical modeling and hardware testing, a High Efficiency Microwave Power Amplifier was built that demonstrated conversion efficiencies four to five times higher than current state of the art.

  9. High-Efficiency Microwave Power Amplifier

    NASA Technical Reports Server (NTRS)

    Sims, Williams H.

    2005-01-01

    A high-efficiency power amplifier that operates in the S band (frequencies of the order of a few gigahertz) utilizes transistors operating under class-D bias and excitation conditions. Class-D operation has been utilized at lower frequencies, but, until now, has not been exploited in the S band. Nominally, in class D operation, a transistor is switched rapidly between "on" and "off" states so that at any given instant, it sustains either high current or high voltage, but not both at the same time. In the ideal case of zero "on" resistance, infinite "off" resistance, zero inductance and capacitance, and perfect switching, the output signal would be a perfect square wave. Relative to the traditional classes A, B, and C of amplifier operation, class D offers the potential to achieve greater power efficiency. In addition, relative to class-A amplifiers, class-D amplifiers are less likely to go into oscillation. In order to design this amplifier, it was necessary to derive mathematical models of microwave power transistors for incorporation into a larger mathematical model for computational simulation of the operation of a class-D microwave amplifier. The design incorporates state-of-the-art switching techniques applicable only in the microwave frequency range. Another major novel feature is a transmission-line power splitter/combiner designed with the help of phasing techniques to enable an approximation of a square-wave signal (which is inherently a wideband signal) to propagate through what would, if designed in a more traditional manner, behave as a more severely band-limited device (see figure). The amplifier includes an input, a driver, and a final stage. Each stage contains a pair of GaAs-based field-effect transistors biased in class D. The input signal can range from -10 to +10 dBm into a 50-ohm load. The table summarizes the performances of the three stages

  10. Novel Polymers for High Efficiency Renewable and Portable Power Applications

    DTIC Science & Technology

    2015-07-30

    force between the polymer and dye would result in weaker PL quenching and optoelectronic device power conversion efficiency, this experimentally...model. The results could be very useful for materials design for developing high efficiency organic and polymer based optoelectronic devices; 2) Optimum...Apr-2015 Approved for Public Release; Distribution Unlimited Final Report: Novel Polymers for High Efficiency Renewable and Portable Power

  11. High Efficiency Thermoelectric Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    El-Genk, Mohamed; Saber, Hamed; Caillat, Thierry

    2004-01-01

    The work performed and whose results presented in this report is a joint effort between the University of New Mexico s Institute for Space and Nuclear Power Studies (ISNPS) and the Jet Propulsion Laboratory (JPL), California Institute of Technology. In addition to the development, design, and fabrication of skutterudites and skutterudites-based segmented unicouples this effort included conducting performance tests of these unicouples for hundreds of hours to verify theoretical predictions of the conversion efficiency. The performance predictions of these unicouples are obtained using 1-D and 3-D models developed for that purpose and for estimating the actual performance and side heat losses in the tests conducted at ISNPS. In addition to the performance tests, the development of the 1-D and 3-D models and the development of Advanced Radioisotope Power systems for Beginning-Of-Life (BOM) power of 108 We are carried out at ISNPS. The materials synthesis and fabrication of the unicouples are carried out at JPL. The research conducted at ISNPS is documented in chapters 2-5 and that conducted at JP, in documented in chapter 5. An important consideration in the design and optimization of segmented thermoelectric unicouples (STUs) is determining the relative lengths, cross-section areas, and the interfacial temperatures of the segments of the different materials in the n- and p-legs. These variables are determined using a genetic algorithm (GA) in conjunction with one-dimensional analytical model of STUs that is developed in chapter 2. Results indicated that when optimized for maximum conversion efficiency, the interfacial temperatures between various segments in a STU are close to those at the intersections of the Figure-Of-Merit (FOM), ZT, curves of the thermoelectric materials of the adjacent segments. When optimizing the STUs for maximum electrical power density, however, the interfacial temperatures are different from those at the intersections of the ZT curves, but

  12. Plasmonic energy nanofocusing for high-efficiency laser fusion ignition

    NASA Astrophysics Data System (ADS)

    Tanabe, Katsuaki

    2016-08-01

    We propose an efficient laser fusion ignition system consisting of metal nanoparticles or nanoshells embedded in conventional deuterated polystyrene fuel targets. The incident optical energy of the heating laser is highly concentrated around the metallic particulates randomly dispersed inside imploded targets due to the electromagnetic-field-enhancement effect by surface plasmon resonance, and thus effectively triggers nuclear-fusion chain reactions. Our preliminary calculations exhibit field enhancement factors of around 50 and 1100 for spherical Ag nanoparticles and Ag/SiO2 nanoshells, respectively, in the 1-µm band.

  13. High efficiency fuel cell/advanced turbine power cycles

    SciTech Connect

    Morehead, H.

    1995-10-19

    An outline of the Westinghouse high-efficiency fuel cell/advanced turbine power cycle is presented. The following topics are discussed: The Westinghouse SOFC pilot manufacturing facility, cell scale-up plan, pressure effects on SOFC power and efficiency, sureCell versus conventional gas turbine plants, sureCell product line for distributed power applications, 20 MW pressurized-SOFC/gas turbine power plant, 10 MW SOFC/CT power plant, sureCell plant concept design requirements, and Westinghouse SOFC market entry.

  14. High efficiency solar cells for laser power beaming applications

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Landis, G. A.

    1995-01-01

    Understanding solar cell response to pulsed laser outputs is important for the evaluation of power beaming applications. The time response of high efficiency GaAs and silicon solar cells to a 25 nS monochromatic pulse input is described. The PC-1D computer code is used to analyze the cell current during and after the pulse for various conditions.

  15. Fuel Cell/Turbine Ultra High Efficiency Power System

    SciTech Connect

    Hossein, Ghezel-Ayagh

    2001-11-06

    FuelCell Energy, INC. (FCE) is currently involved in the design of ultra high efficiency power plants under a cooperative agreement (DE-FC26-00NT40) managed by the National Energy Technology Laboratory (NETL) as part of the DOE's Vision 21 program. Under this project, FCE is developing a fuel cell/turbine hybrid system that integrates the atmospheric pressure Direct FuelCell{reg_sign} (DFC{reg_sign}) with an unfired Brayton cycle utilizing indirect heat recovery from the power plant. Features of the DFC/T{trademark} system include: high efficiency, minimal emissions, simplicity in design, direct reforming internal to the fuel cell, no pressurization of the fuel cell, independent operating pressure of the fuel cell and turbine, and potential cost competitiveness with existing combined cycle power plants at much smaller sizes. Objectives of the Vision 21 Program include developing power plants that will generate electricity with net efficiencies approaching 75 percent (with natural gas), while producing sulfur and nitrogen oxide emissions of less than 0.01 lb/million BTU. These goals are significant improvements over conventional power plants, which are 35-60 percent efficient and produce emissions of 0.07 to 0.3 lb/million BTU of sulfur and nitrogen oxides. The nitrogen oxide and sulfur emissions from the DFC/T system are anticipated to be better than the Vision 21 goals due to the non-combustion features of the DFC/T power plant. The expected high efficiency of the DFC/T will also result in a 40-50 percent reduction in carbon dioxide emissions compared to conventional power plants. To date, the R&D efforts have resulted in significant progress including proof-of-concept tests of a sub-scale power plant built around a state-of-the-art DFC stack integrated with a modified Capstone Model 330 Microturbine. The objectives of this effort are to investigate the integration aspects of the fuel cell and turbine and to obtain design information and operational data that will

  16. HIGH EFFICIENCY FOSSIL POWER PLANT (HEFPP) CONCEPTUALIZATION PROGRAM

    SciTech Connect

    J.L. Justice

    1999-03-25

    This study confirms the feasibility of a natural gas fueled, 20 MW M-C Power integrated pressurized molten carbonate fuel cell combined in a topping cycle with a gas turbine generator plant. The high efficiency fossil power plant (HEFPP) concept has a 70% efficiency on a LHV basis. The study confirms the HEFPP has a cost advantage on a cost of electricity basis over the gas turbine based combined cycle plants in the 20 MW size range. The study also identifies the areas of further development required for the fuel cell, gas turbine generator, cathode blower, inverter, and power module vessel. The HEFPP concept offers an environmentally friendly power plant with minuscule emission levels when compared with the combined cycle power plant.

  17. 2250-MHz High Efficiency Microwave Power Amplifier (HEMPA)

    NASA Technical Reports Server (NTRS)

    Sims, W. Herbert; Bell, Joseph L. (Technical Monitor)

    2001-01-01

    Tnis paper will focus on developing an exotic switching technique that enhances the DC-to-RF conversion efficiency of microwave power amplifiers. For years, switching techniques implemented in the 10 kHz to 30 MHz region have resulted in DC-to-RF conversion efficiencies of 90-95-percent. Currently amplifier conversion efficiency, in the 2-3 GHz region approaches, 10-20-percent. Using a combination of analytical modeling and hardware testing, a High Efficiency Microwave Power Amplifier was built that demonstrated conversion efficiencies four to five times higher than current state of the art.

  18. Fusion Power Deployment

    SciTech Connect

    J.A. Schmidt; J.M. Ogden

    2002-02-06

    Fusion power plants could be part of a future portfolio of non-carbon dioxide producing energy supplies such as wind, solar, biomass, advanced fission power, and fossil energy with carbon dioxide sequestration. In this paper, we discuss key issues that could impact fusion energy deployment during the last half of this century. These include geographic issues such as resource availability, scale issues, energy storage requirements, and waste issues. The resource needs and waste production associated with fusion deployment in the U.S. should not pose serious problems. One important feature of fusion power is the fact that a fusion power plant should be locatable within most local or regional electrical distribution systems. For this reason, fusion power plants should not increase the burden of long distance power transmission to our distribution system. In contrast to fusion power, regional factors could play an important role in the deployment of renewable resources such as wind, solar and biomass or fossil energy with CO2 sequestration. We examine the role of these regional factors and their implications for fusion power deployment.

  19. a High-Efficiency Fusion Method of Multi-Spectral Image and Panchromatic Image

    NASA Astrophysics Data System (ADS)

    Xue, X.; Wang, J. P.; Wang, H.; Xiang, F.

    2013-07-01

    With the development of modern remote sensing technology, a variety of earth observation satellites could continue to tremendously provide image data of different spatial resolution, time resolution, spectral resolution remote sensing, and the remote sensing data obtained is increasing with great capacity, which forms multi-source image pyramid in the same area. To play the advantages of a variety of remote sensing data, the application of remote sensing image fusion is a very important choice. When remote sensing data is large, fusion is large in computing capacity and time-consuming, so it is difficult to carry out rapid, real-time fusion. However, in some remote sensing applications, such as disaster prevention and relief quick, etc., timely fusion is required. Based on image fusion method of principal component analysis (PCA) and the advantage of parallel computing, a high-efficiency fusion method of multi-spectral image and panchromatic image is proposed. Beijing-1 Micro-satellite is a high-performance small satellite for earth observation,With Beijing-1 Micro-satellite remote sensing images as the experimental data, it is proved that good fusion results of multi-spectral image and panchromatic image can be obtained with the proposed method, and the fusion speed is also fast. At the same time, some measures of improving the efficiency of parallel image fusion are also discussed.

  20. Lunar Helium-3 and Fusion Power

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The NASA Office of Exploration sponsored the NASA Lunar Helium-3 and Fusion Power Workshop. The meeting was held to understand the potential of using He-3 from the moon for terrestrial fusion power production. It provided an overview, two parallel working sessions, a review of sessions, and discussions. The lunar mining session concluded that mining, beneficiation, separation, and return of He-3 from the moon would be possible but that a large scale operation and improved technology is required. The fusion power session concluded that: (1) that He-3 offers significant, possibly compelling, advantages over fusion of tritium, principally increased reactor life, reduced radioactive wastes, and high efficiency conversion, (2) that detailed assessment of the potential of the D/He-3 fuel cycle requires more information, and (3) D/He-3 fusion may be best for commercial purposes, although D/T fusion is more near term.

  1. AMTEC: High efficiency static conversion for space power

    NASA Technical Reports Server (NTRS)

    Bankston, C. P.; Shirbacheh, M.

    1986-01-01

    Future manned and unmanned space missions will require reliable, high efficiency energy conversion systems. For a manned Mars mission, power levels in the range of 10 to 100 kWe will be needed. The Alkali Metal Thermoelectric Converter (AMTEC) is a direct energy conversion technology with the potential to meet these needs. The AMTEC is a thermally regenerative electrochemical device that derives its operation from the sodium ion conducting properties of beta-alumina solid electrolyte (BASE). To date, an efficiency of 19%, area power density of 1 W/sq cm, and a lifetime of 10,000 hours at high temperature were demonstrated in laboratory devices. Systems studies show that projected AMTEC systems equal or surpass the performance of other static or dynamic systems in applications of 1 kWe-1 MWe. Thus, the laboratory experiments and applications studies conducted to date have shown that the AMTEC posseses great potential. In order to bring this technology to the stage where prototype units can be built and operated, several technical issues must be addressed. These include the need for long life, high power electrodes, minimization of radiative parasitic losses, and high temperature seals. In summary, the evidence shows that if AMTEC is developed, it can play a significant role in future space power applications.

  2. A High Efficiency PSOFC/ATS-Gas Turbine Power System

    SciTech Connect

    W.L. Lundberg; G.A. Israelson; M.D. Moeckel; S.E. Veyo; R.A. Holmes; P.R. Zafred; J.E. King; R.E. Kothmann

    2001-02-01

    A study is described in which the conceptual design of a hybrid power system integrating a pressurized Siemens Westinghouse solid oxide fuel cell generator and the Mercury{trademark} 50 gas turbine was developed. The Mercury{trademark} 50 was designed by Solar Turbines as part of the US. Department of Energy Advanced Turbine Systems program. The focus of the study was to develop the hybrid power system concept that principally would exhibit an attractively-low cost of electricity (COE). The inherently-high efficiency of the hybrid cycle contributes directly to achieving this objective, and by employing the efficient, power-intensive Mercury{trademark} 50, with its relatively-low installed cost, the higher-cost SOFC generator can be optimally sized such that the minimum-COE objective is achieved. The system cycle is described, major system components are specified, the system installed cost and COE are estimated, and the physical arrangement of the major system components is discussed. Estimates of system power output, efficiency, and emissions at the system design point are also presented. In addition, two bottoming cycle options are described, and estimates of their effects on overall-system performance, cost, and COE are provided.

  3. High-efficiency heteroepitaxial solar cells for space power applications

    NASA Technical Reports Server (NTRS)

    Vernon, S. M.; Tobin, S. P.; Keavney, C. J.; Wojtczuk, S. J.

    1989-01-01

    The experimental results for several technical approaches aimed at achieving highly efficient solar cells for space-power applications are reported. Efficiencies of up to 24.5 percent (170X, AM0) and 21.7 percent (1X, AM0) have been achieved with homoepitaxial GaAs p/n cells. This one-sun AM0 efficiency value is believed to be the highest reported to date. Tandem solar cells utilizing GaAs-on-Ge structures have been fabricated and shown to have efficiencies up to 21.3 percent (1X, AM0), and a GaAs-on-Si cell at 15.2 percent (1X, AM0) is reported. Homoepitaxial n/p InP cells with an efficiency of 18.8 percent (1X, AM0) are also reported. The fabrication of heteroepitaxial InP solar cells with one-sun AM0 efficiency values of 9.4 percent (on GaAs) and 7.2 percent (on Si) is described.

  4. HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER

    SciTech Connect

    BROWN,LC; BESENBRUCH,GE; LENTSCH,RD; SCHULTZ,KR; FUNK,JF; PICKARD,PS; MARSHALL,AC; SHOWALTER,SK

    2003-06-01

    OAK B202 HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER. Combustion of fossil fuels, used to power transportation, generate electricity, heat homes and fuel industry provides 86% of the world's energy. Drawbacks to fossil fuel utilization include limited supply, pollution, and carbon dioxide emissions. Carbon dioxide emissions, thought to be responsible for global warming, are now the subject of international treaties. Together, these drawbacks argue for the replacement of fossil fuels with a less-polluting potentially renewable primary energy such as nuclear energy. Conventional nuclear plants readily generate electric power but fossil fuels are firmly entrenched in the transportation sector. Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. Hydrogen will be particularly advantageous when coupled with fuel cells. Fuel cells have higher efficiency than conventional battery/internal combustion engine combinations and do not produce nitrogen oxides during low-temperature operation. Contemporary hydrogen production is primarily based on fossil fuels and most specifically on natural gas. When hydrogen is produced using energy derived from fossil fuels, there is little or no environmental advantage. There is currently no large scale, cost-effective, environmentally attractive hydrogen production process available for commercialization, nor has such a process been identified. The objective of this work is to find an economically feasible process for the production of hydrogen, by nuclear means, using an advanced high-temperature nuclear reactor as the primary energy source. Hydrogen production by thermochemical water-splitting (Appendix A), a chemical process that accomplishes the decomposition of water into hydrogen and oxygen using only heat or, in the case of a hybrid thermochemical process, by a combination of heat and electrolysis, could meet these goals. Hydrogen produced from fossil

  5. High efficiency and brightness fluorescent organic light emitting diode by triplet-triplet fusion

    DOEpatents

    Forrest, Stephen; Zhang, Yifan

    2015-02-10

    A first device is provided. The first device further comprises an organic light emitting device. The organic light emitting device further comprises an anode, a cathode, and an emissive layer disposed between the anode and the cathode. The emissive layer may include an organic host compound and at least one organic emitting compound capable of fluorescent emission at room temperature. Various configurations are described for providing a range of current densities in which T-T fusion dominates over S-T annihilation, leading to very high efficiency fluorescent OLEDs.

  6. High Efficiency Solar Power via Separated Photo and Voltaic Pathways

    SciTech Connect

    Michael J. Naughton

    2009-02-17

    This project demonstrates a novel nanostructured solar cell architecture capable of achieving high efficiency levels that is relatively simple and inexpensive to manufacture. The high efficiency will be achieved by the novel structure that separates the path of the photons from the path of the generated charge carriers. In this way, the photon path can be long for maximum light absorption, while the path for carriers can be short for maximum electronic energy harvesting. The combination of maximum light absorption coupled with maximum carrier harvesting is the basis for the expected high efficiency. The project will develop high efficiency solar cell prototypes utilizing this unique nanostructured architecture. The project addresses the fundamental limitation inherent in all current solar cell designs, and which opens a pathway to development for high efficiency solar cells at low cost. Realizing this goal will result in a levelized cost of electricity in the range of 10¢/kWh, which would achieve the long-sought goal of making photovoltaic electricity cost competitive with fossil-fuel generated electricity without any governmental subsidies. This breakthrough would spur the already rapid growth in the photovoltaic industry to an explosive pace, with significant, widespread benefit to the national economy and the nation’s energy security. The initial target of the program is to develop single-junction solar cells using ultrathin amorphous silicon with the performance approaching that of single crystal silicon cells.

  7. High Efficiency Microwave Power Amplifier: From the Lab to Industry

    NASA Technical Reports Server (NTRS)

    Sims, William Herbert, III; Bell, Joseph L. (Technical Monitor)

    2001-01-01

    Since the beginnings of space travel, various microwave power amplifier designs have been employed. These included Class-A, -B, and -C bias arrangements. However, shared limitation of these topologies is the inherent high total consumption of input power associated with the generation of radio frequency (RF)/microwave power. The power amplifier has always been the largest drain for the limited available power on the spacecraft. Typically, the conversion efficiency of a microwave power amplifier is 10 to 20%. For a typical microwave power amplifier of 20 watts, input DC power of at least 100 watts is required. Such a large demand for input power suggests that a better method of RF/microwave power generation is required. The price paid for using a linear amplifier where high linearity is unnecessary includes higher initial and operating costs, lower DC-to-RF conversion efficiency, high power consumption, higher power dissipation and the accompanying need for higher capacity heat removal means, and an amplifier that is more prone to parasitic oscillation. The first use of a higher efficiency mode of power generation was described by Baxandall in 1959. This higher efficiency mode, Class-D, is achieved through distinct switching techniques to reduce the power losses associated with switching, conduction, and gate drive losses of a given transistor.

  8. Cascade: a high-efficiency ICF power reactor

    SciTech Connect

    Pitts, J.H.

    1985-10-31

    Cascade attains a net power-plant efficiency of 49% and its cost is competitive with high-temperature gas-cooled reactor, pressurized-water reactor, and coal-fired power plants. The Cascade reactor and blanket are made of ceramic materials and activation is 6 times less than that of the MARS Tandem Mirror Reactor operating at comparable power. Hands-on maintenance of the heat exchangers is possible one day after shutdown. Essentially all tritium is recovered in the vacuum system, with the remainder recovered from the helium power conversion loop. Tritium leakage external to the vacuum system and power conversion loop is only 0.03 Ci/d.

  9. The path to fusion power.

    PubMed

    Llewellyn Smith, Chris; Ward, David

    2007-04-15

    Fusion is potentially an environmentally responsible and intrinsically safe source of essentially limitless power. It should be possible to build viable fusion power stations, and it looks as if the cost of fusion power will be reasonable. But time is needed to further develop the technology and to test in power station conditions the materials that would be used in their construction. Assuming no major adverse surprises, an orderly fusion development programme could lead to a prototype fusion power station putting electricity into the grid within 30 years, with commercial fusion power following some 10 or more years later. In the second half of the century, fusion could therefore be an important part of the portfolio of measures that are needed to cope with rising demand for energy in an environmentally responsible manner. In this paper, we describe the basics of fusion, its potential attractions, the status of fusion R&D, the remaining challenges and how they will be tackled at the International Tokamak Experimental Reactor and the proposed International Fusion Materials Irradiation Facility, and the timetable for the subsequent commercialization of fusion power.

  10. High efficiency fuel cell/advanced turbine power cycles

    SciTech Connect

    Morehead, H.

    1996-12-31

    The following figures are included: Westinghouse (W.) SOFC pilot manufacturing facility; cell scale-up plan; W. 25 kW SOFC unit at the utility`s facility on Rokko Island; pressure effect on SOFC power and efficiency; SureCELL{trademark} vs conventional gas turbine plants; SureCELL{trademark} product line for distributed power applications; 20 MW pressurized SOFC/gas turbine power plant; 10 MW SOFT/CT power plant; SureCELL{trademark} plant concept design requirements; and W. SOFC market entry.

  11. High efficiency GaP power conversion for Betavoltaic applications

    NASA Technical Reports Server (NTRS)

    Sims, Paul E.; Dinetta, Louis C.; Barnett, Allen M.

    1994-01-01

    AstroPower is developing a gallium phosphide (GaP) based energy converter optimized for radio luminescent light-based power supplies. A 'two-step' or 'indirect' process is used where a phosphor is excited by radioactive decay products to produce light that is then converted to electricity by a photovoltaic energy converter. This indirect conversion of beta-radiation to electrical energy can be realized by applying recent developments in tritium based radio luminescent (RL) light sources in combination with the high conversion efficiencies that can be achieved under low illumination with low leakage, gallium phosphide based devices. This tritium to light approach is inherently safer than battery designs that incorporate high activity radionuclides because the beta particles emitted by tritium are of low average energy and are easily stopped by a thin layer of glass. GaP layers were grown by liquid phase epitaxy and p/n junction devices were fabricated and characterized for low light intensity power conversion. AstroPower has demonstrated the feasibility of the GaP based energy converter with the following key results: 23.54 percent conversion efficiency under 968 muW/sq cm 440 nm blue light, 14.59 percent conversion efficiency for 2.85 muW/sq cm 440 nm blue light, and fabrication of working 5 V array. We have also determined that at least 20 muW/sq cm optical power is available for betavoltaic power systems. Successful developments of this device is an enabling technology for low volume, safe, high voltage, milliwatt power supplies with service lifetimes in excess of 12 years.

  12. High efficiency GaP power conversion for Betavoltaic applications

    NASA Astrophysics Data System (ADS)

    Sims, Paul E.; Dinetta, Louis C.; Barnett, Allen M.

    1994-09-01

    AstroPower is developing a gallium phosphide (GaP) based energy converter optimized for radio luminescent light-based power supplies. A 'two-step' or 'indirect' process is used where a phosphor is excited by radioactive decay products to produce light that is then converted to electricity by a photovoltaic energy converter. This indirect conversion of beta-radiation to electrical energy can be realized by applying recent developments in tritium based radio luminescent (RL) light sources in combination with the high conversion efficiencies that can be achieved under low illumination with low leakage, gallium phosphide based devices. This tritium to light approach is inherently safer than battery designs that incorporate high activity radionuclides because the beta particles emitted by tritium are of low average energy and are easily stopped by a thin layer of glass. GaP layers were grown by liquid phase epitaxy and p/n junction devices were fabricated and characterized for low light intensity power conversion. AstroPower has demonstrated the feasibility of the GaP based energy converter with the following key results: 23.54 percent conversion efficiency under 968 muW/sq cm 440 nm blue light, 14.59 percent conversion efficiency for 2.85 muW/sq cm 440 nm blue light, and fabrication of working 5 V array. We have also determined that at least 20 muW/sq cm optical power is available for betavoltaic power systems. Successful developments of this device is an enabling technology for low volume, safe, high voltage, milliwatt power supplies with service lifetimes in excess of 12 years.

  13. High-Efficiency Hall Thruster Discharge Power Converter

    NASA Technical Reports Server (NTRS)

    Jaquish, Thomas

    2015-01-01

    Busek Company, Inc., is designing, building, and testing a new printed circuit board converter. The new converter consists of two series or parallel boards (slices) intended to power a high-voltage Hall accelerator (HiVHAC) thruster or other similarly sized electric propulsion devices. The converter accepts 80- to 160-V input and generates 200- to 700-V isolated output while delivering continually adjustable 300-W to 3.5-kW power. Busek built and demonstrated one board that achieved nearly 94 percent efficiency the first time it was turned on, with projected efficiency exceeding 97 percent following timing software optimization. The board has a projected specific mass of 1.2 kg/kW, achieved through high-frequency switching. In Phase II, Busek optimized to exceed 97 percent efficiency and built a second prototype in a form factor more appropriate for flight. This converter then was integrated with a set of upgraded existing boards for powering magnets and the cathode. The program culminated with integrating the entire power processing unit and testing it on a Busek thruster and on NASA's HiVHAC thruster.

  14. Fusion Power Demonstration III

    SciTech Connect

    Lee, J.D.

    1985-07-01

    This is the third in the series of reports covering the Fusion Power Demonstration (FPD) design study. This volume considers the FPD-III configuration that incorporates an octopole end plug. As compared with the quadrupole end-plugged designs of FPD-I and FPD-II, this octopole configuration reduces the number of end cell magnets and shortens the minimum ignition length of the central cell. The end-cell plasma length is also reduced, which in turn reduces the size and cost of the end cell magnets and shielding. As a contiuation in the series of documents covering the FPD, this report does not stand alone as a design description of FPD-III. Design details of FPD-III subsystems that do not differ significantly from those of the FPD-II configuration are not duplicated in this report.

  15. High efficiency carbonate fuel cell/turbine hybrid power cycles

    SciTech Connect

    Steinfeld, G.

    1995-10-19

    Carbonate fuel cells developed by Energy Research Corporation, in commercial 2.85 MW size, have an efficiency of 57.9 percent. Studies of higher efficiency hybrid power cycles were conducted in cooperation with METC to identify an economically competitive system with an efficiency in excess of 65 percent. A hybrid power cycle was identified that includes a direct carbonate fuel cell, a gas turbine and a steam cycle, which generates power at a LHV efficiency in excess of 70 percent. This new system is called a Tandem Technology Cycle (TTC). In a TTC operating on natural gas fuel, 95 percent of the fuel is mixed with recycled fuel cell anode exhaust, providing water for the reforming of the fuel, and flows to a direct carbonate fuel cell system which generates 72 percent of the power. The portion of the fuel cell anode exhaust which is not recycled, is burned and heat is transferred to the compressed air from a gas turbine, raising its temperature to 1800{degrees}F. The stream is then heated to 2000{degrees}F in the gas turbine burner and expands through the turbine generating 13 percent of the power. Half the exhaust from the gas turbine flows to the anode exhaust burner, and the remainder flows to the fuel cell cathodes providing the O{sub 2} and CO{sub 2} needed in the electrochemical reaction. Exhaust from the fuel cells flows to a steam system which includes a heat recovery steam generator and stages steam turbine which generates 15 percent of the TTC system power. Studies of the TTC for 200-MW and 20-MW size plants quantified performance, emissions and cost-of-electricity, and compared the characteristics of the TTC to gas turbine combined cycles. A 200-MW TTC plant has an efficiency of 72.6 percent, and is relatively insensitive to ambient temperature, but requires a heat exchanger capable of 2000{degrees}F. The estimated cost of electricity is 45.8 mills/kWhr which is not competitive with a combined cycle in installations where fuel cost is under $5.8/MMBtu.

  16. High-Efficiency, Low-Weight Power Transformer

    NASA Technical Reports Server (NTRS)

    Welsh, J. P.

    1986-01-01

    Technology for design and fabrication of radically new type of conductioncooled high-power (25 kVA) lightweight transformer having outstanding thermal and electrical characteristics. Fulfills longstanding need for conduction-cooled transformers and magnetics with low internal thermal resistances. Development techniques limited to conductive heat transfer, since other techniques such as liquid cooling, forced liquid cooling, and evaporative cooling of transformers impractical in zero-gravity space environment. Transformer uniquely designed: mechanical structure also serves as thermal paths for conduction cooling of magnetic core and windings.

  17. High Efficiency Ka-Band Solid State Power Amplifier Waveguide Power Combiner

    NASA Technical Reports Server (NTRS)

    Wintucky, Edwin G.; Simons, Rainee N.; Chevalier, Christine T.; Freeman, Jon C.

    2010-01-01

    A novel Ka-band high efficiency asymmetric waveguide four-port combiner for coherent combining of two Monolithic Microwave Integrated Circuit (MMIC) Solid State Power Amplifiers (SSPAs) having unequal outputs has been successfully designed, fabricated and characterized over the NASA deep space frequency band from 31.8 to 32.3 GHz. The measured combiner efficiency is greater than 90 percent, the return loss greater than 18 dB and input port isolation greater than 22 dB. The manufactured combiner was designed for an input power ratio of 2:1 but can be custom designed for any arbitrary power ratio. Applications considered are NASA s space communications systems needing 6 to 10 W of radio frequency (RF) power. This Technical Memorandum (TM) is an expanded version of the article recently published in Institute of Engineering and Technology (IET) Electronics Letters.

  18. Pulsed Power Driven Fusion Energy

    SciTech Connect

    SLUTZ,STEPHEN A.

    1999-11-22

    Pulsed power is a robust and inexpensive technology for obtaining high powers. Considerable progress has been made on developing light ion beams as a means of transporting this power to inertial fusion capsules. However, further progress is hampered by the lack of an adequate ion source. Alternatively, z-pinches can efficiently convert pulsed power into thermal radiation, which can be used to drive an inertial fusion capsule. However, a z-pinch driven fusion explosion will destroy a portion of the transmission line that delivers the electrical power to the z-pinch. They investigate several options for providing standoff for z-pinch driven fusion. Recyclable Transmission Lines (RTLs) appear to be the most promising approach.

  19. Fusion Power measurement at ITER

    SciTech Connect

    Bertalot, L.; Barnsley, R.; Krasilnikov, V.; Stott, P.; Suarez, A.; Vayakis, G.; Walsh, M.

    2015-07-01

    Nuclear fusion research aims to provide energy for the future in a sustainable way and the ITER project scope is to demonstrate the feasibility of nuclear fusion energy. ITER is a nuclear experimental reactor based on a large scale fusion plasma (tokamak type) device generating Deuterium - Tritium (DT) fusion reactions with emission of 14 MeV neutrons producing up to 700 MW fusion power. The measurement of fusion power, i.e. total neutron emissivity, will play an important role for achieving ITER goals, in particular the fusion gain factor Q related to the reactor performance. Particular attention is given also to the development of the neutron calibration strategy whose main scope is to achieve the required accuracy of 10% for the measurement of fusion power. Neutron Flux Monitors located in diagnostic ports and inside the vacuum vessel will measure ITER total neutron emissivity, expected to range from 1014 n/s in Deuterium - Deuterium (DD) plasmas up to almost 10{sup 21} n/s in DT plasmas. The neutron detection systems as well all other ITER diagnostics have to withstand high nuclear radiation and electromagnetic fields as well ultrahigh vacuum and thermal loads. (authors)

  20. Conversion Tower for Dispatchable Solar Power: High-Efficiency Solar-Electric Conversion Power Tower

    SciTech Connect

    2012-01-11

    HEATS Project: Abengoa Solar is developing a high-efficiency solar-electric conversion tower to enable low-cost, fully dispatchable solar energy generation. Abengoa’s conversion tower utilizes new system architecture and a two-phase thermal energy storage media with an efficient supercritical carbon dioxide (CO2) power cycle. The company is using a high-temperature heat-transfer fluid with a phase change in between its hot and cold operating temperature. The fluid serves as a heat storage material and is cheaper and more efficient than conventional heat-storage materials, like molten salt. It also allows the use of a high heat flux solar receiver, advanced high thermal energy density storage, and more efficient power cycles.

  1. Cascade inertial-confinement-fusion power plant

    SciTech Connect

    Pitts, J.H.; Maya, I.

    1985-11-13

    The Cascade reactor is double-cone shaped with a maximum radius of 5 m. It rotates at 50 rpm. The average temperature of a three-material flowing granular blanket leaving the reactor is 1440 K. Heat from the blanket is transferred to helium gas in a shell- and ceramic-tube-type heat exchanger that has a separate region for each blanket material. Diffusion of tritium from the blanket granules through the heat exchanger is only 25 Ci/d, so no intermediate loop is needed for isolation. We selected a simple once-through, regenerative, 5-MPa helium gas-turbine (Brayton) cycle for power conversion because of its simplicity and high efficiency. Fusion power is 1500 MW; this is multiplied to 1670 MW/sub t/ in the blanket. Power conversion efficiency is 55%. Net electric power is 815 MW/sub e/, produced with a net plant efficiency of 49%.

  2. High efficiency WCDMA power amplifier with Pulsed Load Modulation (PLM) technique

    NASA Astrophysics Data System (ADS)

    Liao, Shu-Hsien

    In wireless communication, high data rate complex modulation is used for spectral efficiency. However, power efficiency of power amplifier degrades when complex modulation is applied. Therefore, efficiency enhancement is necessary to maintain the performance. However, conventional efficiency enhancement schemes are nonlinear and performance improvement can only be optimized over a small range of power level. In order to preserve linearity and power efficiency, we propose a new digital power amplification technique "Pulsed Load Modulation (PLM)" for high efficiency and linear amplification. The PLM technique realizes load impedance modulation in digital fashion which is insensitive to device nonlinearity. Furthermore, the optimum power efficiency can be maintained over a wide range of output power. In this work, a PLM power amplifier module has been fabricated and to demonstrate the ability of PLM to provide high efficiency and linear amplification.

  3. Power scaling of high-efficiency 1.5 μm cascaded Raman fiber lasers.

    PubMed

    Supradeepa, V R; Nicholson, Jeffrey W

    2013-07-15

    High-power fiber lasers operating at the 1.5 μm wavelength region have attractive features, such as eye safety and atmospheric transparency, and cascaded Raman fiber lasers offer a convenient method to obtain high-power sources at these wavelengths. A limitation to power scaling, however, has been the lower conversion efficiency of these lasers. We recently introduced a high-efficiency architecture for high-power cascaded Raman fiber lasers applicable for 1.5 μm fiber lasers. Here we demonstrate further power scaling using this new architecture. Using numerical simulations, we identify the ideal operating conditions for the new architecture. We demonstrate a high-efficiency 1480 nm cascaded Raman fiber laser with an output power of 301 W, comparable to record power levels achieved with rare-earth-doped fiber lasers in the 1.5 μm wavelength region.

  4. A high efficiency C-band internally-matched harmonic tuning GaN power amplifier

    NASA Astrophysics Data System (ADS)

    Lu, Y.; Zhao, B. C.; Zheng, J. X.; Zhang, H. S.; Zheng, X. F.; Ma, X. H.; Hao, Y.; Ma, P. J.

    2016-09-01

    In this paper, a high efficiency C-band gallium nitride (GaN) internally-matched power amplifier (PA) is presented. This amplifier consists of 2-chips of self-developed GaN high-electron mobility transistors (HEMTs) with 16 mm total gate width on SiC substrate. New harmonic manipulation circuits are induced both in the input and output matching networks for high efficiency matching at fundamental and 2nd-harmonic frequency, respectively. The developed amplifier has achieved 72.1% power added efficiency (PAE) with 107.4 W output power at 5 GHz. To the best of our knowledge, this amplifier exhibits the highest PAE in C-band GaN HEMT amplifiers with over 100 W output power. Additionally, 1000 hours' aging test reveals high reliability for practical applications.

  5. Time-reversal duality of high-efficiency RF power amplifiers

    SciTech Connect

    Reveyrand, T; Ramos, I; Popovic, Z

    2012-12-06

    The similarity between RF power amplifiers and rectifiers is discussed. It is shown that the same high-efficiency harmonically-terminated power amplifier can be operated in a dual rectifier mode. Nonlinear simulations with a GaN HEMT transistor model show the time-reversal intrinsic voltage and current waveform relationship between a class-F amplifier and rectifier. Measurements on a class-F-1 amplifier and rectifier at 2.14 GHz demonstrate over 80% efficiency in both cases.

  6. Highly efficient and high-power diode-pumped femtosecond Yb:LYSO laser

    NASA Astrophysics Data System (ADS)

    Tian, Wenlong; Wang, Zhaohua; Zhu, Jiangfeng; Zheng, Lihe; Xu, Jun; Wei, Zhiyi

    2017-04-01

    A diode-pumped high-power femtosecond Yb:LYSO laser with high efficiency is demonstrated. With a semiconductor saturable absorber mirror for passive mode-locking and a Gires–Tournois interferometer mirror for intracavity dispersion compensation, stable mode-locking pulses of 297 fs duration at 1042 nm were obtained. The maximum average power of 3.07 W was realized under 5.17 W absorbed pump power, corresponding to as high as 59.4% opt–opt efficiency. The single pulse energy and peak power are about 35.5 nJ and 119.5 kW, respectively.

  7. Advanced Concepts: Aneutronic Fusion Power and Propulsion

    NASA Technical Reports Server (NTRS)

    Chapman, John J.

    2012-01-01

    Aneutronic Fusion for In-Space thrust, power. Clean energy & potential nuclear gains. Fusion plant concepts, potential to use advanced fuels. Methods to harness ionic momentum for high Isp thrust plus direct power conversion into electricity will be presented.

  8. Fusion power for space propulsion.

    NASA Technical Reports Server (NTRS)

    Roth, R.; Rayle, W.; Reinmann, J.

    1972-01-01

    Principles of operation, interplanetary orbit-to-orbit mission capabilities, technical problems, and environmental safeguards are examined for thermonuclear fusion propulsion systems. Two systems examined include (1) a fusion-electric concept in which kinetic energy of charged particles from the plasma is converted into electric power (for accelerating the propellant in an electrostatic thrustor) by the van de Graaf generator principle and (2) the direct fusion rocket in which energetic plasma lost from the reactor has a suitable amount of added propellant to obtain the optimum exhaust velocity. The deuterium-tritium and the deuterium/helium-3 reactions are considered as suitable candidates, and attention is given to problems of cryogenic refrigeration systems, magnet shielding, and high-energy particle extraction and guidance.

  9. Electrical heating of soils using high efficiency electrode patterns and power phases

    DOEpatents

    Buettner, Harley M.

    1999-01-01

    Powerline-frequency electrical (joule) heating of soils using a high efficiency electrode configuration and power phase arrangement. The electrode configuration consists of several heating or current injection electrodes around the periphery of a volume of soil to be heated, all electrodes being connected to one phase of a multi-phase or a single-phase power system, and a return or extraction electrode or electrodes located inside the volume to be heated being connected to the remaining phases of the multi-phase power system or to the neutral side of the single-phase power source. This electrode configuration and power phase arrangement can be utilized anywhere where powerline frequency soil heating is applicable and thus has many potential uses including removal of volatile organic compounds such as gasoline and tricholorethylene (TCE) from contaminated areas.

  10. Pulsed Power Fusion Program update

    SciTech Connect

    Quintenz, J.P.; Adams, R.G.; Allshouse, G.O.

    1998-06-01

    The US Department of Energy has supported a substantial research program in Inertial Confinement Fusion (ICF) since the early 1970s. Over the course of the ensuing 25 years, pulsed power energy, efficiency, and relatively low cost of the technology when compared to the mainline ICF approach involving large glass lasers. These compelling advantages of pulsed power, however, have been tempered with the difficulty that has been encountered in concentrating the energy in space and time to create the high energy and power density required to achieve temperatures useful in indirect drive ICF. Since the Beams `96 meeting two years ago, the situation has changed dramatically and extremely high x-ray power ({approximately}290 TW) and energy ({approximately}1.8 MJ) have been produced in fast x-pinch implosions on the Z accelerator. These sources have been utilized to heat hohlraums to >150 eV and have opened the door to important ICF capsule experiments.

  11. Volume Bragg grating narrowed high-power and highly efficient cladding-pumped Raman fiber laser.

    PubMed

    Liu, Jun; Yao, Weichao; Zhao, Chujun; Shen, Deyuan; Fan, Dianyuan

    2014-12-10

    High-power and highly efficient operation of a single-mode cladding-pumped Raman fiber laser with narrow lasing bandwidth is demonstrated. The spectral narrowing was realized by an external cavity containing a volume Bragg grating with a center wavelength of 1658 nm. A maximum output power of 10.4 W at 1658.3 nm with a spectral linewidth (FWHM) of ∼0.1  nm was obtained for the launched pump power of 18.4 W, corresponding to a slope efficiency of 109% with respect to the launched pump power. Lasing characteristics of free-running operation are also evaluated and discussed.

  12. Evolution of Automotive Chopper Circuits Towards Ultra High Efficiency and Power Density

    NASA Astrophysics Data System (ADS)

    Pavlovsky, Martin; Tsuruta, Yukinori; Kawamura, Atsuo

    Automotive industry is considered to be one of the main contributors to environmental pollution and global warming. Therefore, many car manufacturers are in near future planning to introduce hybrid electric vehicles (HEV), fuel cell electric vehicles (FCEV) and pure electric vehicles (EV) to make our cars more environmentally friendly. These new vehicles require highly efficient and small power converters. In recent years, considerable improvements were made in designing such converters. In this paper, an approach based on so called Snubber Assisted Zero Voltage and Zero Current Switching topology otherwise also known as SAZZ is presented. This topology has evolved to be one of the leaders in the field of highly efficient converters with high power densities. Evolution and main features of this topology are briefly discussed. Capabilities of the topology are demonstrated on two case study prototypes based on different design approaches. The prototypes are designed to be fully bi-directional for peak power output of 30kW. Both designs reached efficiencies close to 99% in wide load range. Power densities over 40kW/litre are attainable in the same time. Combination of MOSFET technology and SAZZ topology is shown to be very beneficial to converters designed for EV applications.

  13. High power, high efficiency millimeter wavelength traveling wave tubes for high rate communications from deep space

    NASA Technical Reports Server (NTRS)

    Dayton, James A., Jr.

    1991-01-01

    The high-power transmitters needed for high data rate communications from deep space will require a new class of compact, high efficiency traveling wave tubes (TWT's). Many of the recent TWT developments in the microwave frequency range are generically applicable to mm wave devices, in particular much of the technology of computer aided design, cathodes, and multistage depressed collectors. However, because TWT dimensions scale approximately with wavelength, mm wave devices will be physically much smaller with inherently more stringent fabrication tolerances and sensitivity to thermal dissipation.

  14. A low-power, high-efficiency Ka-band TWTA

    NASA Astrophysics Data System (ADS)

    Curren, Arthur N.; Dayton, James A., Jr.; Palmer, Raymond W.; Force, Dale A.; Tamashiro, Rodney N.; Wilson, John F.; Dombro, Louis; Harvey, Wayne L.

    1992-03-01

    NASA has developed a new class of Ka-band TWT amplifiers (TWTAs) which achieve their high efficiency/low power performance goals by means of an advanced dynamic velocity taper (DVT). The DVT is characterized by a continuous, nonlinear reduction in helix pitch from its initial synchronous value in the output section of the TWT to near the end of the helix. Another efficiency-maximizing feature is the inclusion of a multistage depressed collector employing oxygen-free, high-conductivity Cu electrodes treated for secondary electron emission suppression by means of ion bombardment. An efficiency of 43 percent is expected to be reached.

  15. A low-power, high-efficiency Ka-band TWTA

    NASA Technical Reports Server (NTRS)

    Curren, Arthur N.; Dayton, James A., Jr.; Palmer, Raymond W.; Force, Dale A.; Tamashiro, Rodney N.; Wilson, John F.; Dombro, Louis; Harvey, Wayne L.

    1992-01-01

    NASA has developed a new class of Ka-band TWT amplifiers (TWTAs) which achieve their high efficiency/low power performance goals by means of an advanced dynamic velocity taper (DVT). The DVT is characterized by a continuous, nonlinear reduction in helix pitch from its initial synchronous value in the output section of the TWT to near the end of the helix. Another efficiency-maximizing feature is the inclusion of a multistage depressed collector employing oxygen-free, high-conductivity Cu electrodes treated for secondary electron emission suppression by means of ion bombardment. An efficiency of 43 percent is expected to be reached.

  16. Ka-Band TWT High-Efficiency Power Combiner for High-Rate Data Transmission

    NASA Technical Reports Server (NTRS)

    Wintucky, Edwin G.; Simons, Rainee; Vaden, Karl R.; Lesny, Gary G.; Glass, Jeffrey L.

    2007-01-01

    A four-port magic-T hybrid waveguide junction serves as the central component of a high-efficiency two-way power combiner circuit for transmitting a high-rate phase-modulated digital signal at a carrier frequency in the Ka-band (between 27 and 40 GHz). This power combiner was developed to satisfy a specific requirement to efficiently combine the coherent outputs of two traveling-wavetube (TWT) amplifiers that are typically characterized by power levels on the order of 100 W or more. In this application, the use of a waveguide-based power combiner (instead of a coaxial-cable- or microstrip-based power combiner, for example) is dictated by requirements for low loss, high power-handling capability, and broadband response. Combiner efficiencies were typically 90 percent or more over both the linear and saturated output power regions of operation of the TWTs . Figure 1 depicts the basic configuration of the magic-T hybrid junction. The coherent outputs of the two TWTs enter through ports 1 and 4. As a result of the orientations of the electromagnetic fields, which also provides a needed high port-to-port isolation, of these two input signals and the interior design of the magic-T junction, the input powers are divided so as to add in phase at one output port (port 2), and to be opposite in phase and hence cancel each other at the opposite coplanar output port (port 3). The net result is that the output power at port 2 is essentially double that of the output of one TWT, minus the power lost in the magic-T hybrid junction. Optimum performance as a high-efficiency power combiner thus requires a balance of both power and phase at the input ports of the magic-T. Replicas of this two-way combiner can be arranged in a binary configuration to obtain a 2n-way (where n is an integer) combiner. For example, Figure 2 illustrates the use of three two-way combiners to combine the outputs of four TWTs.

  17. High-Efficiency Ka-Band Waveguide Two-Way Asymmetric Power Combiner

    NASA Technical Reports Server (NTRS)

    Wintucky, E. G.; Simons, R. N.; Freeman, J. C.; Chevalier, C. T.

    2011-01-01

    NASA is planning a number of Space Exploration, Earth Observation and Space Science missions where Ka-band solid-state power amplifiers (SSPAs) could have a role. Monolithic microwave integrated circuit (MMIC) based SSPAs with output powers on the order of 10 W at Ka-band frequencies would be adequate to satisfy the data transmission rate requirements at the distances involved. MMICs are a type of integrated circuit fabricated on a GaAs wafer, which operates at micro wave frequencies and performs the function of signal amplification. The highest power Ka-band (31.8 to 32.3 GHz) SSPA to have flown in space had an output power of 2.6 W with an overall efficiency of 14.3 percent. This SSPA was built around discrete GaAs pHEMT (high electron mobility transistor) devices and flew aboard the Deep Space One spacecraft. State-of-the-art GaAs pHEMT-based MMIC power amplifiers (PAs) can deliver RF power at Ka-band frequencies anywhere from 3 W with a power added efficiency (PAE) of 32 percent to 6 W with a PAE of 26 percent. However, to achieve power levels higher than 6 W, the output of several MMIC PAs would need to be combined using a high-efficiency power combiner. Conventional binary waveguide power combiners, based on short-slot and magic-T circuits, require MMIC PAs with identical amplitude and phase characteristics for high combining efficiency. However, due to manufacturing process variations, the output powers of the MMIC PAs tend to be unequal, and hence the need to develop unequal power combiners. A two-way asymmetric magic-T based power combiner for MMIC power amplifiers, which can take in unequal inputs, has been successfully designed, fabricated, and characterized over NASA s Deep Space Network (DSN) frequency range of 31.8 to 32.3 GHz. The figure is a transparent view of the a sym - metric combiner that shows the 4-port configuration and the internal structure. The rod, post, and iris are positioned by design to achieve the desired asymmetric power ratio

  18. High-efficiency, high-average-power, CW Yb:YAG zigzag slab master oscillator power amplifier at room temperature.

    PubMed

    Chen, Xiaoming; Xu, Liu; Hu, Hao; Zhou, Tangjian; Sun, Yinhong; Jiang, Hao; Lei, Jun; Lv, Wenqiang; Su, Hua; Shi, Yong; Li, Mi; Wu, Yingchen; Yao, Zhenyu; Zhao, Na; Xu, Xiaoxiao; Gao, Qingsong; Wang, Xiaojun; Tang, Chun

    2016-10-17

    We demonstrate a high-efficiency, high-average-power, CW master oscillator power amplifier based on a conduction-cooled, end-pumped Yb:YAG slab architecture at room temperature (RT). Firstly, the CW amplification property is theoretically analyzed based on the kinetics model for Yb:YAG. To realize high-efficiency laser amplification extraction for RT Yb:YAG, not only intense pump but also a high-power seed laser is of great importance. Experimentally, a composite Yb:YAG crystal slab with three doped and two un-doped segments symmetrically is employed as the gain medium, which is end-pumped by two high-power, 940-nm diode lasers. A high-power, narrow-spectral-width, 1030-nm fiber seed laser then double passes the composite slab to realize efficient power amplification. For 0.8-kW seed input, maximum output power of 3.54 kW is obtained at 6.7 kW of pump power, with the optical conversion efficiency of 41% and the highest slope efficiency of 59%. To the best of our knowledge, this is the highest power and efficiency reported for Yb:YAG lasing at RT except thin-disk lasers.

  19. High Efficiency Power Combining of Ka-Band TWTs for High Data Rate Communications

    NASA Technical Reports Server (NTRS)

    Wintucky, E. G.; Simons, R. N.; Vaden, K. R.; Lesny, G. G.; Glass, J. L.

    2006-01-01

    Future NASA deep space exploration missions are expected in some cases to require telecommunication systems capable of operating at very high data rates (potentially 1 Gbps or more) for the transmission back to Earth of large volumes of scientific data, which means high frequency transmitters with large bandwidth. Among the Ka band frequencies of interest are the present 500 MHz Deep Space Network (DSN) band of 31.8 to 32.3 GHz and a broader band at 37-38 GHz allocated for space science [1]. The large distances and use of practical antenna sizes dictate the need for high transmitter power of up to 1 kW or more. High electrical efficiency is also a requirement. The approach investigated by NASA GRC is a novel wave guide power combiner architecture based on a hybrid magic-T junction for combining the power output from multiple TWTs [1,2]. This architecture was successfully demonstrated and is capable of both high efficiency (90-95%, depending on frequency) and high data rate transmission (up to 622 Mbps) in a two-way power combiner circuit for two different pairs of Ka band TWTs at two different frequency bands. One pair of TWTs, tested over a frequency range of 29.1 to 29.6 GHz, consisted of two 110-115W TWTs previously used in uplink data transmission evaluation terminals in the NASA Advanced Communications Technology Satellite (ACTS) program [1,2]. The second pair was two 100W TWTs (Boeing 999H) designed for high efficiency operation (greater than 55%) over the DSN frequency band of 31.8 to 32.3 GHz [3]. The presentation will provide a qualitative description of the wave guide circuit, results for power combining and data transmission measurements, and results of computer modeling of the magic-T and alternative hybrid junctions for improvements in efficiency and power handling capability. The power combiner results presented here are relevant not only to NASA deep space exploration missions, but also to other U.S. Government agency programs.

  20. Silicon-Carbide Power MOSFET Performance in High Efficiency Boost Power Processing Unit for Extreme Environments

    NASA Technical Reports Server (NTRS)

    Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Del Castillo, Linda Y.; Fitzpatrick, Fred; Chen, Yuan

    2016-01-01

    Silicon-Carbide device technology has generated much interest in recent years. With superior thermal performance, power ratings and potential switching frequencies over its Silicon counterpart, Silicon-Carbide offers a greater possibility for high powered switching applications in extreme environment. In particular, Silicon-Carbide Metal-Oxide- Semiconductor Field-Effect Transistors' (MOSFETs) maturing process technology has produced a plethora of commercially available power dense, low on-state resistance devices capable of switching at high frequencies. A novel hard-switched power processing unit (PPU) is implemented utilizing Silicon-Carbide power devices. Accelerated life data is captured and assessed in conjunction with a damage accumulation model of gate oxide and drain-source junction lifetime to evaluate potential system performance at high temperature environments.

  1. A high-efficiency power cycle in which hydrogen is compressed by absorption in metal hydrides.

    PubMed

    Powell, J R; Salzano, F J; Yu, W S; Milau, J S

    1976-07-23

    A high-efficiency power cycle is proposed in which molecular hydrogen gas is used as a working fluid in a regenerative closed Brayton cycle. The hydrogen gas is compressed by an absorption-desorption cycle on metal hydride (FeTiH(x)) beds. Low-temperature solar or geothermal heat (temperature about 100 degrees C) is used for the compression process, and high-temperature fossil fuel or nuclear heat (temperature about 700 degrees C) supplies the expansion work in the turbine. Typically, about 90 percent of the high-temperature heat input is converted to electricity, while about 3 kilowatts of low-temperature heat is required per kilowatt of electrical output.

  2. High Power High Efficiency Ka-Band Power Combiners for Solid-State Devices

    NASA Technical Reports Server (NTRS)

    Freeman, Jon C.; Wintucky, Edwin G.; Chevalier, Christine T.

    2006-01-01

    Wide-band power combining units for Ka-band are simulated for use as MMIC amplifier applications. Short-slot couplers as well as magic-tees are the basic elements for the combiners. Wide bandwidth (5 GHz) and low insertion (approx.0.2 dB) and high combining efficiencies (approx.90 percent) are obtained.

  3. Indirect drive targets for fusion power

    DOEpatents

    Amendt, Peter A.; Miles, Robin R.

    2016-10-11

    A hohlraum for an inertial confinement fusion power plant is disclosed. The hohlraum includes a generally cylindrical exterior surface, and an interior rugby ball-shaped surface. Windows over laser entrance holes at each end of the hohlraum enclose inert gas. Infrared reflectors on opposite sides of the central point reflect fusion chamber heat away from the capsule. P2 shields disposed on the infrared reflectors help assure an enhanced and more uniform x-ray bath for the fusion fuel capsule.

  4. Improvement of force factor of magnetostrictive vibration power generator for high efficiency

    NASA Astrophysics Data System (ADS)

    Kita, Shota; Ueno, Toshiyuki; Yamada, Sotoshi

    2015-05-01

    We develop high power magnetostrictive vibration power generator for battery-free wireless electronics. The generator is based on a cantilever of parallel beam structure consisting of coil-wound Galfenol and stainless plates with permanent magnet for bias. Oscillating force exerted on the tip bends the cantilever in vibration yields stress variation of Galfenol plate, which causes flux variation and generates voltage on coil due to the law of induction. This generator has advantages over conventional, such as piezoelectric or moving magnet types, in the point of high efficiency, highly robust, and low electrical impedance. Our concern is the improvement of energy conversion efficiency dependent on the dimension. Especially, force factor, the conversion ratio of the electromotive force (voltage) on the tip velocity in vibration, has an important role in energy conversion process. First, the theoretical value of the force factor is formulated and then the validity was verified by experiments, where we compare four types of prototype with parameters of the dimension using 7.0 × 1.5 × 50 mm beams of Galfenol with 1606-turn wound coil. In addition, the energy conversion efficiency of the prototypes depending on load resistance was measured. The most efficient prototype exhibits the maximum instantaneous power of 0.73 W and energy of 4.7 mJ at a free vibration of frequency of 202 Hz in the case of applied force is 25 N. Further, it was found that energy conversion efficiency depends not only on the force factor but also on the damping (mechanical loss) of the vibration.

  5. Improvement of force factor of magnetostrictive vibration power generator for high efficiency

    SciTech Connect

    Kita, Shota Ueno, Toshiyuki; Yamada, Sotoshi

    2015-05-07

    We develop high power magnetostrictive vibration power generator for battery-free wireless electronics. The generator is based on a cantilever of parallel beam structure consisting of coil-wound Galfenol and stainless plates with permanent magnet for bias. Oscillating force exerted on the tip bends the cantilever in vibration yields stress variation of Galfenol plate, which causes flux variation and generates voltage on coil due to the law of induction. This generator has advantages over conventional, such as piezoelectric or moving magnet types, in the point of high efficiency, highly robust, and low electrical impedance. Our concern is the improvement of energy conversion efficiency dependent on the dimension. Especially, force factor, the conversion ratio of the electromotive force (voltage) on the tip velocity in vibration, has an important role in energy conversion process. First, the theoretical value of the force factor is formulated and then the validity was verified by experiments, where we compare four types of prototype with parameters of the dimension using 7.0 × 1.5 × 50 mm beams of Galfenol with 1606-turn wound coil. In addition, the energy conversion efficiency of the prototypes depending on load resistance was measured. The most efficient prototype exhibits the maximum instantaneous power of 0.73 W and energy of 4.7 mJ at a free vibration of frequency of 202 Hz in the case of applied force is 25 N. Further, it was found that energy conversion efficiency depends not only on the force factor but also on the damping (mechanical loss) of the vibration.

  6. Perspectives on Magnetized Target Fusion Power Plants

    NASA Astrophysics Data System (ADS)

    Miller, R. L.

    2007-06-01

    One approach to Magnetized Target Fusion (MTF) builds upon the ongoing experimental effort (FRX-L) to generate a Field Reversed Configuration (FRC) target plasma suitable for translation and cylindrical-liner (i.e., converging flux conserver) implosion. Numerical modeling is underway to elucidate key performance drivers for possible future power-plant extrapolations. The fusion gain, Q (ratio of DT fusion yield to the sum of initial liner kinetic energy plus plasma formation energy), sets the power-plant duty cycle for a nominal design electric power [ e.g. 1,000 MWe(net)]. A pulsed MTF power plant of this type derives from the historic Fast Liner Reactor (FLR) concept and shares attributes with the recent Inertial Fusion Energy (IFE) Z-pinch and laser-driven pellet HYLIFE-II conceptual designs.

  7. Progress toward achieving high power and high efficiency semipolar LEDs and their characterization

    NASA Astrophysics Data System (ADS)

    Zhong, Hong

    Performance of current commercially available wurtzite nitride based light-emitting diodes (LEDs), grown along the polar (0001) c-plane orientation, is limited by the presence of polarization-related electric fields inside multi-quantum wells (MQWs). The discontinuities in both spontaneous and piezoelectric polarization at the heterointerfaces result in internal electric fields in the quantum wells. These electric fields cause carrier separation [quantum confined Stark effect (QCSE)] and reduce the radiative recombination rate within the quantum wells. One approach to reduce and possibly eliminate the polarization-related effects is to grow III-nitride devices on crystal planes that are inclined with respect to the c-axis, i.e., on semipolar planes. In this dissertation, metalorganic chemical vapor deposition (MOCVD) has been employed for the homoepitaxial growth of GaN based LEDs on semipolar orientations. As a consequence of growing on high-quality bulk GaN substrates, the LEDs have significantly reduced threading dislocation and stacking fault densities, resulting in remarkable improvements in EQE and output power. High efficiency semipolar (1011) violet-blue and blue LEDs have been demonstrated without any intentional effort to enhance the light extraction from those devices. Optimizations of epitaxial structures have led to increased output power and external quantum efficiency. A silicone encapsulated single quantum well blue LED with peak wavelength of 444 nm with output power of 24.3 mW, external quantum efficiency of 43% and luminous efficacy of 75 lm/W (with phosphorescent coating) at 20 mA has been demonstrated. Polarization fields in strained (1011) and (112¯2) InGaN quantum wells have been experimentally determined through bias-dependent optical studies. Our results show that the polarization field flips its direction in semipolar InGaN quantum wells with large inclination angles (i.e. around 60°). This suggests that there exists a polarization

  8. Performance Assessment of Baseline Cells for the High Efficiency Space Power Systems Project

    NASA Technical Reports Server (NTRS)

    Schneidegger, Brianne T.

    2012-01-01

    The Enabling Technology Development and Demonstration (ETDD) Program High Efficiency Space Power Systems (HESPS) Project, formerly the Exploration Technology Development Program (ETDP) Energy Storage Project is tasked with developing advanced lithium-ion cells for future NASA Exploration missions. Under this project, components under development via various in-house and contracted efforts are delivered to Saft America for scale-up and integration into cells. Progress toward meeting project goals will be measured by comparing the performance to these cells with cells of a similar format with Saft s state-of-the-art aerospace chemistry. This report discusses the results of testing performed on the first set of baseline cells delivered by Saft to the NASA Glenn Research Center. This build is a cylindrical "DD" geometry with a 10 Ah nameplate capacity. Testing is being performed to establish baseline cell performance at conditions relevant to ETDD HESPS Battery Key Performance Parameter (KPP) goals including various temperatures, rates, and cycle life conditions. Data obtained from these cells will serve as a performance baseline for future cell builds containing optimized ETDD HESPSdeveloped materials. A test plan for these cells was developed to measure cell performance against the high energy cell KPP goals. The goal for cell-level specific energy of the high energy technology is 180 Wh/kg at a C/10 discharge rate and 0 C. The cells should operate for at least 2000 cycles at 100 percent DOD with 80 percent capacity retention. Baseline DD cells delivered 152 Wh/kg at 20 C. This number decreased to 143.9 Wh/kg with a 0 C discharge. This report provides performance data and summarizes results of the testing performed on the DD cells.

  9. High Efficiency Generation of Hydrogen Fuels using Nuclear Power Annual Report August, 2000 - July 2001

    SciTech Connect

    Brown, L.C.

    2002-11-01

    OAK B188 High Efficiency Generation of Hydrogen Fuels using Nuclear Power Annual Report August 2000 - July 2001. Currently no large scale, cost-effective, environmentally attractive hydrogen production process is available for commercialization nor has such a process been identified. Hydrogen is a promising energy carrier, which potentially could replace the fossil fuels used in the transportation sector of our economy. Carbon dioxide emissions from fossil fuel combustion are thought to be responsible for global warming. The purpose of this work is to determine the potential for efficient, cost-effective, large-scale production of hydrogen utilizing high temperature heat from an advanced nuclear power station. The benefits of this work will include the generation of a low-polluting transportable energy feedstock in an efficient method that has little or no implication for greenhouse gas emissions from a primary energy source whose availability and sources are domestically controlled. This will help to ensure energy for a future transportation/energy infrastructure that is not influenced/controlled by foreign governments. This report describes work accomplished during the second year (Phase 2) of a three year project whose objective is to ''define an economically feasible concept for production of hydrogen, by nuclear means, using an advanced high temperature nuclear reactor as the energy source.'' The emphasis of the first year (Phase 1) was to evaluate thermochemical processes which offer the potential for efficient, cost-effective, large-scale production of hydrogen from water, in which the primary energy input is high temperature heat from an advanced nuclear reactor and to select one (or, at most, three) for further detailed consideration. Phase 1 met its goals and did select one process, the sulfur-iodine process, for investigation in Phases 2 and 3. The combined goals of Phases 2 and 3 were to select the advanced nuclear reactor best suited to driving the

  10. EDITORIAL: Safety aspects of fusion power plants

    NASA Astrophysics Data System (ADS)

    Kolbasov, B. N.

    2007-07-01

    This special issue of Nuclear Fusion contains 13 informative papers that were initially presented at the 8th IAEA Technical Meeting on Fusion Power Plant Safety held in Vienna, Austria, 10-13 July 2006. Following recommendation from the International Fusion Research Council, the IAEA organizes Technical Meetings on Fusion Safety with the aim to bring together experts to discuss the ongoing work, share new ideas and outline general guidance and recommendations on different issues related to safety and environmental (S&E) aspects of fusion research and power facilities. Previous meetings in this series were held in Vienna, Austria (1980), Ispra, Italy (1983), Culham, UK (1986), Jackson Hole, USA (1989), Toronto, Canada (1993), Naka, Japan (1996) and Cannes, France (2000). The recognized progress in fusion research and technology over the last quarter of a century has boosted the awareness of the potential of fusion to be a practically inexhaustible and clean source of energy. The decision to construct the International Thermonuclear Experimental Reactor (ITER) represents a landmark in the path to fusion power engineering. Ongoing activities to license ITER in France look for an adequate balance between technological and scientific deliverables and complying with safety requirements. Actually, this is the first instance of licensing a representative fusion machine, and it will very likely shape the way in which a more common basis for establishing safety standards and policies for licensing future fusion power plants will be developed. Now that ITER licensing activities are underway, it is becoming clear that the international fusion community should strengthen its efforts in the area of designing the next generations of fusion power plants—demonstrational and commercial. Therefore, the 8th IAEA Technical Meeting on Fusion Safety focused on the safety aspects of power facilities. Some ITER-related safety issues were reported and discussed owing to their potential

  11. Third-Harmonic Envelope Feedback Method for High-Efficiency Linear Power Amplifiers

    NASA Astrophysics Data System (ADS)

    Oshima, Shoichi; Ugajin, Mamoru; Harada, Mitsuru

    A new low-power feedback structure for a power amplifier (PA) reduces signal distortion while keeping the power efficiency of the PA high. The feedback structure injects the envelope of the third-order harmonics into the input signal. In adopting this method for a class-A amplifier, we obtain over 10% higher efficiency while maintaining the same adjacent channel power ratio (ACPR). The power consumption of additional circuit is 200µW.

  12. Triboelectric-pyroelectric-piezoelectric hybrid cell for high-efficiency energy-harvesting and self-powered sensing.

    PubMed

    Zi, Yunlong; Lin, Long; Wang, Jie; Wang, Sihong; Chen, Jun; Fan, Xing; Yang, Po-Kang; Yi, Fang; Wang, Zhong Lin

    2015-04-08

    A triboelectric-pyroelectric-piezoelectric hybrid cell, consisting of a triboelectric nanogenerator and a pyroelectric-piezoelectric nanogenerator, is developed for highly efficient mechanical energy harvesting through multiple mechanisms. The excellent performance of the hybrid cell enhances the energy-harvesting efficiency significantly (by 26.2% at 1 kΩ load resistance), and enables self-powered sensing, which will lead to a variety of advanced applications.

  13. Ultra-high efficiency photovoltaic cells for large scale solar power generation.

    PubMed

    Nakano, Yoshiaki

    2012-01-01

    The primary targets of our project are to drastically improve the photovoltaic conversion efficiency and to develop new energy storage and delivery technologies. Our approach to obtain an efficiency over 40% starts from the improvement of III-V multi-junction solar cells by introducing a novel material for each cell realizing an ideal combination of bandgaps and lattice-matching. Further improvement incorporates quantum structures such as stacked quantum wells and quantum dots, which allow higher degree of freedom in the design of the bandgap and the lattice strain. Highly controlled arrangement of either quantum dots or quantum wells permits the coupling of the wavefunctions, and thus forms intermediate bands in the bandgap of a host material, which allows multiple photon absorption theoretically leading to a conversion efficiency exceeding 50%. In addition to such improvements, microfabrication technology for the integrated high-efficiency cells and the development of novel material systems that realizes high efficiency and low cost at the same time are investigated.

  14. Demonstration of a Highly Efficient Solid Oxide Fuel Cell Power System Using Adiabatic Steam Reforming and Anode Gas Recirculation

    SciTech Connect

    Powell, Michael R.; Meinhardt, Kerry D.; Sprenkle, Vincent L.; Chick, Lawrence A.; Mcvay, Gary L.

    2012-05-01

    Solid oxide fuel cells (SOFC) are currently being developed for a wide variety of applications because of their high efficiency at multiple power levels. Applications for SOFCs encompass a large range of power levels including 1-2 kW residential combined heat and power applications, 100-250 kW sized systems for distributed generation and grid extension, and MW-scale power plants utilizing coal. This paper reports on the development of a highly efficient, small-scale SOFC power system operating on methane. The system uses adiabatic steam reforming of methane and anode gas recirculation to achieve high net electrical efficiency. The anode exit gas is recirculated and all of the heat and water required for the endothermic reforming reaction are provided by the anode gas emerging from the SOFC stack. Although the single-pass fuel utilization is only about 55%, because of the anode gas recirculation the overall fuel utilization is up to 93%. The demonstrated system achieved gross power output of 1650 to 2150 watts with a maximum net LHV efficiency of 56.7% at 1720 watts. Overall system efficiency could be further improved to over 60% with use of properly sized blowers.

  15. Highly efficient welding power supply. Final report, May 1, 1978-September 30, 1980

    SciTech Connect

    Thommes, J M

    1980-09-01

    The results and findings of an energy efficient welding power development project are presented. The power source developed is to be used for electric arc welding processes in which 3.5 trillion Btu of energy (1978 example year) can be saved annually. The power source development incorporates the use of switch mode power supply techniques in order to convert industrial supply mains (230/460 VAC 3 phi 60 Hz) to appropriate welding voltages and currents (up to 32 volts/up to 300 amps). A series capacitor switch mode power circuit was the circuit technique chosen in order to optimize energy efficiency, costs, reliability, size/weight, and welding performance. Test results demonstrated an effective efficiency (taking into account idle power consumption) of 80 to 91% for the energy efficient power source while the conventional types of power sources tested ranged from 41 to 74% efficiency. Line power factor was also improved for the energy efficient power source. Field tests indicated additional refinements of weld process performance and power source audible noise emission reduction could be beneficial.

  16. Laser space power system for Moon: Ecological safety and high efficiency

    SciTech Connect

    Smakhtin, A.P.; Mosesov, S.K.

    1997-12-31

    The power supply of a space base placed on the Moon is a central problem in the development of the Moon as the nearest celestial body to the Earth. At the present time some different versions of the Moon`s base power supply with using chemical, solar, and nuclear power converters on the Moon`s surface are considered. The comparative analysis of the use of Space Power Systems which are placed in a low and a high lunar orbits and transmit electromagnetic power from the lunar orbit to the Moon`s base by the trapping of a focused electromagnetic beam is performed in this paper. From the results of this analysis it follows that such Space Power Systems may be an alternative power supply system to traditional systems and they offer few advantages over last mentioned systems in the near future. Space Power System with using solar pumped laser as means for power conversion and power transportation is particularly promising for solution to the problem of power supply of the Moon`s base.

  17. High-efficiency high-power cw solid state lasers for material processing

    NASA Astrophysics Data System (ADS)

    Weber, Heinz P.; Graf, Thomas; Weber, Rudolf

    2000-02-01

    The maximum power range over which a laser resonator supports stable oscillation is mainly determined by the material constants of the active medium and by the cooling schemes. The power range for stable fundamental-mode operation can be shifted to higher powers with special cavity design and intra-cavity optics but the width of the stability range will be unaffected and can be enlarged only with adaptive optics. We present investigations on a multi- rod laser cavity and a high-power side-pumped laser system. In order to obtain constant beam parameters with varying power we prose a novel self-adaptive method to compensate for the power-dependent thermal lenses in high-power lasers.

  18. Fusion Propulsion and Power for Future Flight

    NASA Technical Reports Server (NTRS)

    Froning, H. D., Jr.

    1996-01-01

    There are innovative magnetic and electric confinement fusion power and propulsion system designs with potential for: vacuum specific impulses of 1500-2000 seconds with rocket engine thrust/mass ratios of 5-10 g's; environmentally favorable exhaust emissions if aneutronic fusion propellants can be used; a 2 to 3-fold reduction in the mass of hypersonic airliners and SSTO aerospace planes; a 10 to 20 fold reduction in Mars expedition mass and cost (if propellant from planetary atmospheres is used); and feasibility or in-feasibility of these systems could be confirmed with a modest applied research and exploratory development cost.

  19. Alternative lattice options for energy recovery in high-average-power high-efficiency free-electron lasers

    SciTech Connect

    Piot, P.; /Northern Illinois U. /NICADD, DeKalb /Fermilab

    2009-03-01

    High-average-power free-electron lasers often rely on energy-recovering linacs. In a high-efficiency free electron laser, the main limitation to high average power stems from the fractional energy spread induced by the free-electron laser process. Managing beams with large fractional energy spread while simultaneously avoiding beam losses is extremely challenging and relies on intricate longitudinal phase space manipulations. In this paper we discuss a possible alternative technique that makes use of an emittance exchange between one of the transverse and the longitudinal phase spaces.

  20. Pulsed power accelerators for particle beam fusion

    SciTech Connect

    Martin, T.H.; Barr, G.W.; VanDevender, J.P.; White, R.A.; Johnson, D.L.

    1980-01-01

    Sandia National Laboratories is completing the construction phase of the Particle Beam Fusion Accelerator-I (PBFA-I). Testing of the 36 module, 30 TW, 1 MJ output accelerator is in the initial stages. The 4 MJ, PBFA Marx generator has provided 3.6 MA into water-copper sulfate load resistors with a spread from first to last Marx firing between 15 to 25 ns and an output power of 5.7 TW. This accelerator is a modular, lower voltage, pulsed power device that is capable of scaling to power levels exceeding 100 TW. The elements of the PBFA technology and their integration into an accelerator system for particle beam fusion will be discussed.

  1. Switching coordination of distributed dc-dc converters for highly efficient photovoltaic power plants

    SciTech Connect

    Agamy, Mohammed; Elasser, Ahmed; Sabate, Juan Antonio; Galbraith, Anthony William; Harfman Todorovic, Maja

    2014-09-09

    A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.

  2. High-efficiency wireless power delivery for medical implants using hybrid coils.

    PubMed

    Artan, N Sertac; Patel, Ramesh C; Ning, Chengzhi; Chao, H Jonathan

    2012-01-01

    With the exciting developments in the implant technology allowing sophisticated signal processing, stimulation, and drug delivery capabilities, there is new hope for many patients of epilepsy, Parkinson's disease, and stroke to improve their quality of life. Such implants require high power to deliver the promised rich functionality. Yet, delivering high power to implants without damaging the tissue due to heating while keeping the implant footprint small is a challenge. In this paper, we propose a hybrid multi-layer coil as the secondary coil to provide a power and space-efficient solution. The proposed coils can deliver power to an implant for long durations without increasing the skin temperature over 1C.

  3. Self-Powered Wireless Smart Sensor Node Enabled by an Ultrastable, Highly Efficient, and Superhydrophobic-Surface-Based Triboelectric Nanogenerator.

    PubMed

    Zhao, Kun; Wang, Zhong Lin; Yang, Ya

    2016-09-27

    Wireless sensor networks will be responsible for a majority of the fast growth in intelligent systems in the next decade. However, most of the wireless smart sensor nodes require an external power source such as a Li-ion battery, where the labor cost and environmental waste issues of replacing batteries have largely limited the practical applications. Instead of using a Li-ion battery, we report an ultrastable, highly efficient, and superhydrophobic-surface-based triboelectric nanogenerator (TENG) to scavenge wind energy for sustainably powering a wireless smart temperature sensor node. There is no decrease in the output voltage and current of the TENG after continuous working for about 14 h at a wind speed of 12 m/s. Through a power management circuit, the TENG can deliver a constant output voltage of 3.3 V and a pulsed output current of about 100 mA to achieve highly efficient energy storage in a capacitor. A wireless smart temperature sensor node can be sustainably powered by the TENG for sending the real-time temperature data to an iPhone under a working distance of 26 m, demonstrating the feasibility of the self-powered wireless smart sensor networks.

  4. Methodology for Scaling Fusion Power Plant Availability

    SciTech Connect

    Lester M. Waganer

    2011-01-04

    Normally in the U.S. fusion power plant conceptual design studies, the development of the plant availability and the plant capital and operating costs makes the implicit assumption that the plant is a 10th of a kind fusion power plant. This is in keeping with the DOE guidelines published in the 1970s, the PNL report1, "Fusion Reactor Design Studies - Standard Accounts for Cost Estimates. This assumption specifically defines the level of the industry and technology maturity and eliminates the need to define the necessary research and development efforts and costs to construct a one of a kind or the first of a kind power plant. It also assumes all the "teething" problems have been solved and the plant can operate in the manner intended. The plant availability analysis assumes all maintenance actions have been refined and optimized by the operation of the prior nine or so plants. The actions are defined to be as quick and efficient as possible. This study will present a methodology to enable estimation of the availability of the one of a kind (one OAK) plant or first of a kind (1st OAK) plant. To clarify, one of the OAK facilities might be the pilot plant or the demo plant that is prototypical of the next generation power plant, but it is not a full-scale fusion power plant with all fully validated "mature" subsystems. The first OAK facility is truly the first commercial plant of a common design that represents the next generation plant design. However, its subsystems, maintenance equipment and procedures will continue to be refined to achieve the goals for the 10th OAK power plant.

  5. High Efficiency Nuclear Power Plants using Liquid Fluoride Thorium Reactor Technology

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Rarick, Richard A.; Rangarajan, Rajmohan

    2009-01-01

    An overall system analysis approach is used to propose potential conceptual designs of advanced terrestrial nuclear power plants based on Oak Ridge National Laboratory (ORNL) Molten Salt Reactor (MSR) experience and utilizing Closed Cycle Gas Turbine (CCGT) thermal-to-electric energy conversion technology. In particular conceptual designs for an advanced 1 GWe power plant with turbine reheat and compressor intercooling at a 950 K turbine inlet temperature (TIT), as well as near term 100 MWe demonstration plants with TITS of 950 K and 1200 K are presented. Power plant performance data were obtained for TITS ranging from 650 to 1300 K by use of a Closed Brayton Cycle (CBC) systems code which considered the interaction between major sub-systems, including the Liquid Fluoride Thorium Reactor (LFTR), heat source and heat sink heat exchangers, turbo -generator machinery, and an electric power generation and transmission system. Optional off-shore submarine installation of the power plant is a major consideration.

  6. High Efficiency Nuclear Power Plants Using Liquid Fluoride Thorium Reactor Technology

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.; Rarick, Richard A.; Rangarajan, Rajmohan

    2009-01-01

    An overall system analysis approach is used to propose potential conceptual designs of advanced terrestrial nuclear power plants based on Oak Ridge National Laboratory (ORNL) Molten Salt Reactor (MSR) experience and utilizing Closed Cycle Gas Turbine (CCGT) thermal-to-electric energy conversion technology. In particular conceptual designs for an advanced 1 GWe power plant with turbine reheat and compressor intercooling at a 950 K turbine inlet temperature (TIT), as well as near term 100 MWe demonstration plants with TITs of 950 and 1200 K are presented. Power plant performance data were obtained for TITs ranging from 650 to 1300 K by use of a Closed Brayton Cycle (CBC) systems code which considered the interaction between major sub-systems, including the Liquid Fluoride Thorium Reactor (LFTR), heat source and heat sink heat exchangers, turbo-generator machinery, and an electric power generation and transmission system. Optional off-shore submarine installation of the power plant is a major consideration.

  7. Highly efficient high power CW and Q-switched Ho:YLF laser

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, J.

    2015-06-01

    An efficient operation of a Ho:YLF laser pumped by a Tm-doped fibre laser is reported. The research in a continuous-wave (CW) operation was done for two crystals of the same 0.5 at.%Ho dopant concentration and with different lengths (3×3×30 mm3 and 3×3×50 mm3). For an output coupling transmission of 20% and a crystal length of 50 mm, the maximum CWoutput power of 38.9 W for 81.4 W of incident pump power, corresponding to the slope efficiency of 52.3% and optical-to-optical conversion efficiency of 47.8% (determined with respect to the incident pump power) was achieved. The highest opti- cal-to-optical conversion efficiency of 70.2% with respect to the absorbed pump power was obtained. The influence of a heat-sink cooling water temperature on theCWlaser performance was studied. For a Q-switched operation the pulse repe- tition frequency (PRF) was changed from 2 to 10 kHz. The maximum average output power of 34.1 W at the PRF of 10 kHz was obtained for a 50 mm holmium crystal length. For 2 kHz PRF and 71.9 W of incident pump power, pulse energies of 13.7 mJ with a 21 ns FWHM pulse width corresponding to 652 kW peak power were recorded.

  8. All-metal metamaterial slow-wave structure for high-power sources with high efficiency

    SciTech Connect

    Wang, Yanshuai; Duan, Zhaoyun Tang, Xianfeng; Wang, Zhanliang; Zhang, Yabin; Gong, Yubin; Feng, Jinjun

    2015-10-12

    In this paper, we have proposed a metamaterial (MTM) which is suitable for the compact high-power vacuum electron devices. For example, an S-band slow-wave structure (SWS) based on the all-metal MTMs has been studied by both simulation and experiment. The results show that this MTM SWS is very helpful to miniaturize the high-power vacuum electron devices and largely improve the output power and the electronic efficiency. The simulation model of an S-band MTM backward wave oscillator (BWO) is built, and the particle-in-cell simulated results are presented here: a 2.454 GHz signal is generated and its peak output power is 4.0 MW with a higher electronic efficiency of 31.5% relative to the conventional BWOs.

  9. High-power and highly efficient diode-cladding-pumped Ho3+-doped silica fiber lasers.

    PubMed

    Jackson, Stuart D; Bugge, Frank; Erbert, Götz

    2007-11-15

    We demonstrate high-power operation from a singly Ho3+-doped silica fiber laser that is cladding pumped directly with diode lasers operating at 1150 nm. Internal slope efficiencies approaching the Stokes limit were produced, and the maximum output power was 2.2W. This result was achieved using a low Ho3+-ion concentration and La3+-ion codoping, which together limit the transfer of energy between excited Ho3+ ions.

  10. Modeling of high efficiency solar cells under laser pulse for power beaming applications

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Landis, Geoffrey A.

    1994-01-01

    Solar cells have been used to convert sunlight to electrical energy for many years and also offer great potential for non-solar energy conversion applications. Their greatly improved performance under monochromatic light compared to sunlight, makes them suitable as photovoltaic (PV) receivers in laser power beaming applications. Laser beamed power to a PV array receiver could provide power to satellites, an orbital transfer vehicle, or a lunar base. Gallium arsenide (GaAs) and indium phosphide (InP) solar cells have calculated efficiencies of more than 50 percent under continuous illumination at the optimum wavelength. Currently high power free-electron lasers are being developed which operate in pulsed conditions. Understanding cell behavior under a laser pulse is important in the selection of the solar cell material and the laser. An experiment by NAsA lewis and JPL at the AVLIS laser facility in Livermore, CA presented experimental data on cell performance under pulsed laser illumination. Reference 5 contains an overview of technical issues concerning the use of solar cells for laser power conversion, written before the experiments were performed. As the experimental results showed, the actual effects of pulsed operation are more complicated. Reference 6 discusses simulations of the output of GaAs concentrator solar cells under pulsed laser illumination. The present paper continues this work, and compares the output of Si and GaAs solar cells.

  11. Modeling of high efficiency solar cells under laser pulse for power beaming applications

    NASA Astrophysics Data System (ADS)

    Jain, Raj K.; Landis, Geoffrey A.

    1994-09-01

    Solar cells have been used to convert sunlight to electrical energy for many years and also offer great potential for non-solar energy conversion applications. Their greatly improved performance under monochromatic light compared to sunlight, makes them suitable as photovoltaic (PV) receivers in laser power beaming applications. Laser beamed power to a PV array receiver could provide power to satellites, an orbital transfer vehicle, or a lunar base. Gallium arsenide (GaAs) and indium phosphide (InP) solar cells have calculated efficiencies of more than 50 percent under continuous illumination at the optimum wavelength. Currently high power free-electron lasers are being developed which operate in pulsed conditions. Understanding cell behavior under a laser pulse is important in the selection of the solar cell material and the laser. An experiment by NAsA lewis and JPL at the AVLIS laser facility in Livermore, CA presented experimental data on cell performance under pulsed laser illumination. Reference 5 contains an overview of technical issues concerning the use of solar cells for laser power conversion, written before the experiments were performed. As the experimental results showed, the actual effects of pulsed operation are more complicated. Reference 6 discusses simulations of the output of GaAs concentrator solar cells under pulsed laser illumination. The present paper continues this work, and compares the output of Si and GaAs solar cells.

  12. High-efficiency, high-output-power antiguide laser diode arrays

    NASA Technical Reports Server (NTRS)

    Mehuys, D.; Major, J. S., Jr.; Welch, D.; Scifres, D. R.

    1992-01-01

    Antiguide laser arrays have been fabricated and operated up to peak pulsed powers of 7.7 W in a beam with a full-width at half-maximum in the main lobe of 0.7 deg. Up to 0.7 W of continuous wave power is emitted into a radiation pattern 2.5 times the diffraction limit. By varying the temperature of the array to vary the operating wavelength of the device, the threshold gain condition of the array modes is altered, allowing thermal tuning of the far field of the device.

  13. High-efficiency tunable Y-branch power splitters at terahertz frequencies

    NASA Astrophysics Data System (ADS)

    Zou, Jinhua; You, Yun; Deng, Xiaohua; Shen, Linfang; Wu, Jin-Jei; Yang, Tzong-Jer

    2017-03-01

    Terahertz Y-branch power splitters formed by one-way waveguide are investigated theoretically. For such splitters, there exists no backward reflection from the Y-junction region for incident waves because the input channel supports no backward-propagating mode, therefore the transmission efficiency is perfect in the lossless case. Moreover, by varying the applied external magnetic field, the power splitting ratio of the splitters can be tunable for a given frequency, and required (equal or unequal) splitting ratio can also be achieved over a wide frequency band.

  14. Ultra Clean 1.1MW High Efficiency Natural Gas Engine Powered System

    SciTech Connect

    Zurlo, James; Lueck, Steve

    2011-08-31

    Dresser, Inc. (GE Energy, Waukesha gas engines) will develop, test, demonstrate, and commercialize a 1.1 Megawatt (MW) natural gas fueled combined heat and power reciprocating engine powered package. This package will feature a total efficiency > 75% and ultra low CARB permitting emissions. Our modular design will cover the 1 – 6 MW size range, and this scalable technology can be used in both smaller and larger engine powered CHP packages. To further advance one of the key advantages of reciprocating engines, the engine, generator and CHP package will be optimized for low initial and operating costs. Dresser, Inc. will leverage the knowledge gained in the DOE - ARES program. Dresser, Inc. will work with commercial, regulatory, and government entities to help break down barriers to wider deployment of CHP. The outcome of this project will be a commercially successful 1.1 MW CHP package with high electrical and total efficiency that will significantly reduce emissions compared to the current central power plant paradigm. Principal objectives by phases for Budget Period 1 include: • Phase 1 – market study to determine optimum system performance, target first cost, lifecycle cost, and creation of a detailed product specification. • Phase 2 – Refinement of the Waukesha CHP system design concepts, identification of critical characteristics, initial evaluation of technical solutions, and risk mitigation plans. Background

  15. High power, high efficiency, 2D laser diode arrays for pumping solid state lasers

    SciTech Connect

    Rosenberg, A.; McShea, J.C.; Bogdan, A.R.; Petheram, J.C.; Rosen, A.

    1987-11-01

    This document reports the current performance of 2D laser diode arrays operating at 770 nm and 808 nm for pumping promethium and neodymium solid state lasers, respectively. Typical power densities are in excess of 2kw/cm/sup 2/ with overall efficiencies greater than 30%.

  16. Studies of basic mechanisms in high pressure gases: Applications to high efficiency high power lasers

    NASA Technical Reports Server (NTRS)

    Verdeyen, J. T.; Cherrington, B. E.; Leslie, S. G.; Millar, W. S.; Edwards, B. E.

    1976-01-01

    A high power pulsed dye laser was used to optically excite high pressure cesium-xenon mixtures and the resulting measurements are presented. A microwave discharge in rubidium at relatively high xenon pressure was achieved. Preliminary studies of cadium-rare gas mixtures are discussed and a detailed description of the entire experimental apparatus is given.

  17. Modeling of High Efficiency Solar Cells Under Laser Pulse for Power Beaming Applications

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Landis, Geoffrey A.

    1994-01-01

    Solar cells may be used as receivers for laser power beaming. To understand the behavior of solar cells when illuminated by a pulsed laser, the time response of gallium arsenide and silicon solar cells to pulsed monochromatic input has been modeled using a finite element solar cell model.

  18. 160 W high-power, high-efficiency, near-diffraction-limited beam quality all-fiber picosecond pulse laser

    NASA Astrophysics Data System (ADS)

    Sun, Chang; Ge, Tingwu; An, Na; Cao, Kang; Wang, Zhiyong

    2016-10-01

    We experimentally demonstrate a high-power, high-efficiency, near-diffraction-limited beam quality all-fiber picosecond pulse laser, which consists of a passively mode-locked seed laser and three-stage master power amplifiers. A repetition frequency multiplier and a high Yb-doped gain fiber with shorter length are utilized in the laser system to suppress the nonlinear effects and reduce the pulse broadening caused by dispersion. Moreover, the homemade light mode controllers based on a coiling and tapering fiber technique and the active fiber of the amplifier with a relatively small mode area are adopted to improve the beam quality. In addition, by experimentally adjusting the active fiber length, the optical conversion efficiency of the overall laser system can be optimized. Eventually, a 160 W high-power, high-efficiency, near-diffraction-limited picosecond pulse fiber laser is obtained, with the beam quality factor M2 at 1.12 and an optical conversion efficiency of the system of 75%.

  19. A High-Density, High-Efficiency, Isolated On-Board Vehicle Battery Charger Utilizing Silicon Carbide Power Devices

    SciTech Connect

    Whitaker, B; Barkley, A; Cole, Z; Passmore, B; Martin, D; McNutt, TR; Lostetter, AB; Lee, JS; Shiozaki, K

    2014-05-01

    This paper presents an isolated on-board vehicular battery charger that utilizes silicon carbide (SiC) power devices to achieve high density and high efficiency for application in electric vehicles (EVs) and plug-in hybrid EVs (PHEVs). The proposed level 2 charger has a two-stage architecture where the first stage is a bridgeless boost ac-dc converter and the second stage is a phase-shifted full-bridge isolated dc-dc converter. The operation of both topologies is presented and the specific advantages gained through the use of SiC power devices are discussed. The design of power stage components, the packaging of the multichip power module, and the system-level packaging is presented with a primary focus on system density and a secondary focus on system efficiency. In this work, a hardware prototype is developed and a peak system efficiency of 95% is measured while operating both power stages with a switching frequency of 200 kHz. A maximum output power of 6.1 kW results in a volumetric power density of 5.0 kW/L and a gravimetric power density of 3.8 kW/kg when considering the volume and mass of the system including a case.

  20. High-Power, High-Efficiency Ka-Band Space Traveling-Wave Tube

    NASA Technical Reports Server (NTRS)

    Krawczyk, Richard; Wilson, Jeffrey; Simons, Rainee; Williams, Wallace; Bhasin, Kul; Robbins, Neal; Dibb, Daniel; Menninger, William; Zhai, Xiaoling; Benton, Robert; Burdette, James

    2007-01-01

    The L-3 Communications Model 999H traveling-wave tube (TWT) has been demonstrated to generate an output power of 144 W at 60-percent overall efficiency in continuous-wave operation over the frequency band from 31.8 to 32.3 GHz. The best TWT heretofore commercially available for operation in the affected frequency band is characterized by an output power of only 35 W and an efficiency of 50 percent. Moreover, whereas prior TWTs are limited to single output power levels, it has been shown that the output power of the Model 999H can be varied from 54 to 144 W. A TWT is a vacuum electronic device used to amplify microwave signals. TWTs are typically used in free-space communication systems because they are capable of operating at power and efficiency levels significantly higher than those of solid-state devices. In a TWT, an electron beam is generated by an electron gun consisting of a cathode, focusing electrodes, and an anode. The electrons pass through a hole in the anode and are focused into a cylindrical beam by a stack of periodic permanent magnets and travel along the axis of an electrically conductive helix, along which propagates an electromagnetic wave that has been launched by an input signal that is to be amplified. The beam travels within the helix at a velocity close to the phase velocity of the electromagnetic wave. The electromagnetic field decelerates some of the electrons and accelerates others, causing the beam to become formed into electron bunches, which further interact with the electromagnetic wave in such a manner as to surrender kinetic energy to the wave, thereby amplifying the wave. The net result is to amplify the input signal by a factor of about 100,000. After the electrons have passed along the helix, they impinge on electrodes in a collector. The collector decelerates the electrons in such a manner as to recover most of the remaining kinetic energy and thereby significantly increase the power efficiency of the TWT.

  1. Opportunistic replacement of fusion power system parts

    SciTech Connect

    Day, J.A.; George, L.L.

    1981-10-26

    This paper describes a maintenance problem in a fusion power plant. The problem is to specify which life limited parts should be replaced when there is an opportunity. The objective is to minimize the cost rate of replacement parts and of maintenance actions while satisfying a power plant availability constraint. The maintenance policy is to look ahead and replace all parts that will reach their life limits within a time called a screen. Longer screens yield greater system availabilities because more parts are replaced prior to their life limits.

  2. Safeguard Requirements for Fusion Power Plants

    SciTech Connect

    Robert J. Goldston and Alexander Glaser

    2012-08-10

    Nuclear proliferation risks from magnetic fusion energy associated with access to fissile materials can be divided into three main categories: 1) clandestine production of fissile material in an undeclared facility, 2) covert production and diversion of such material in a declared and safeguarded facility, and 3) use of a declared facility in a breakout scenario, in which a state openly produces fissile material in violation of international agreements. The degree of risk in each of these categories is assessed, taking into account both state and non-state actors, and it is found that safeguards are required for fusion energy to be highly attractive from a non-proliferation standpoint. Specific safeguard requirements and R&D needs are outlined for each category of risk, and the technical capability of the ITER experiment, under construction, to contribute to this R&D is noted. A preliminary analysis indicates a potential legal pathway for fusion power systems to be brought under the Treaty for the Non-Proliferation of Nuclear Weapons. "Vertical" proliferation risks associated with tritium and with the knowledge that can be gained from inertial fusion energy R&D are outlined.

  3. Ultra-broad band, low power, highly efficient coherent wavelength conversion in quantum dot SOA.

    PubMed

    Contestabile, G; Yoshida, Y; Maruta, A; Kitayama, K

    2012-12-03

    We report broadband, all-optical wavelength conversion over 100 nm span, in full S- and C-band, with positive conversion efficiency with low optical input power exploiting dual pump Four-Wave-Mixing in a Quantum Dot Semiconductor Optical Amplifier (QD-SOA). We also demonstrate by Error Vector Magnitude analysis the full transparency of the conversion scheme for coherent modulation formats (QPSK, 8-PSK, 16-QAM, OFDM-16QAM) in the whole C-band.

  4. High-Efficiency Food Production in a Renewable Energy Based Micro-Grid Power System

    NASA Technical Reports Server (NTRS)

    Bubenheim, David; Meiners, Dennis

    2016-01-01

    Controlled Environment Agriculture (CEA) systems can be used to produce high-quality, desirable food year round, and the fresh produce can positively contribute to the health and well being of residents in communities with difficult supply logistics. While CEA has many positive outcomes for a remote community, the associated high electric demands have prohibited widespread implementation in what is typically already a fully subscribed power generation and distribution system. Recent advances in CEA technologies as well as renewable power generation, storage, and micro-grid management are increasing system efficiency and expanding the possibilities for enhancing community supporting infrastructure without increasing demands for outside supplied fuels. We will present examples of how new lighting, nutrient delivery, and energy management and control systems can enable significant increases in food production efficiency while maintaining high yields in CEA. Examples from Alaskan communities where initial incorporation of renewable power generation, energy storage and grid management techniques have already reduced diesel fuel consumption for electric generation by more than 40% and expanded grid capacity will be presented. We will discuss how renewable power generation, efficient grid management to extract maximum community service per kW, and novel energy storage approaches can expand the food production, water supply, waste treatment, sanitation and other community support services without traditional increases of consumable fuels supplied from outside the community. These capabilities offer communities with a range of choices to enhance their communities. The examples represent a synergy of technology advancement efforts to develop sustainable community support systems for future space-based human habitats and practical implementation of infrastructure components to increase efficiency and enhance health and well being in remote communities today and tomorrow.

  5. High efficiency direct fuel cell hybrid power cycle for near term application

    SciTech Connect

    Steinfeld, G.; Maru, H.C.; Sanderson, R.A.

    1996-12-31

    Direct carbonate fuel cells being developed by Energy Research Corporation can generate power at an efficiency approaching 60% LHV. This unique fuel cell technology can consume natural gas and other hydrocarbon based fuels directly without requiring an external reformer, thus providing a simpler and inherently efficient power generation system. A 2 MW power plant demonstration of this technology has been initiated at an installation in the city of Santa Clara in California. A 2.85 MW commercial configuration shown in Figure 1 is presently being developed. The complete plant includes the carbonate fuel cell modules, an inverter, transformer and switchgear, a heat recovery unit and supporting instrument air and water treatment systems. The emission levels for this 2.85 MW plant are projected to be orders of magnitude below existing or proposed standards. The 30 year levelized cost of electricity, without inflation, is projected to be approximately 5{cents}/kW-h assuming capital cost for the carbonate fuel cell system of $1000/kW.

  6. An accelerated fusion power development plan

    NASA Astrophysics Data System (ADS)

    Dean, Stephen O.; Baker, Charles C.; Cohn, Daniel R.; Kinkead, Susan D.

    1991-06-01

    Energy for electricity and transportation is a national issue with worldwide environmental and political implications. The world must have energy options for the next century that are not vulnerable to possible disruption for technical, environmental, public confidence, or other reasons. Growing concerns about the greenhouse effect and the safety of transporting oil may lead to reduced burning of coal and other fossil fuels, and the incidents at Three Mile Island and Chernobyl, as well as nuclear waste storage problems, have eroded public acceptance of nuclear fission. Meeting future world energy needs will require improvements in energy efficiency and conservation. However, the world will soon need new central station power plants and increasing amounts of fuel for the transportation sector. The use of fossil fuels, and possibly even fission power, will very likely be restricted because of environmental, safety, and, eventually, supply considerations. Time is running out for policymakers. New energy technologies cannot be brought to the marketplace overnight. Decades are required to bring a new energy production technology from conception to full market penetration. With the added urgency to mitigate deleterious environmental effects of energy use, policymakers must act decisively now to establish and support vigorous energy technology development programs. The U.S. has invested 8 billion over the past 40 years in fusion research and development. If the U.S. fusion program proceeds according to its present strategy, an additional 40 years, and more money, will be expended before fusion will provide commercial electricity. Such an extended schedule is neither cost-effective nor technically necessary. It is time to launch a national venture to construct and operate a fusion power pilot plant. Such a plant could be operational within 15 years of a national commitment to proceed.

  7. Combined Heat and Power Systems Technology Development and Demonstration 370 kW High Efficiency Microturbine

    SciTech Connect

    none,

    2015-10-14

    The C370 Program was awarded in October 2010 with the ambitious goal of designing and testing the most electrically efficient recuperated microturbine engine at a rated power of less than 500 kW. The aggressive targets for electrical efficiency, emission regulatory compliance, and the estimated price point make the system state-of-the-art for microturbine engine systems. These goals will be met by designing a two stage microturbine engine identified as the low pressure spool and high pressure spool that are based on derivative hardware of Capstone’s current commercially available engines. The development and testing of the engine occurred in two phases. Phase I focused on developing a higher power and more efficient engine, that would become the low pressure spool which is based on Capstone’s C200 (200kW) engine architecture. Phase II integrated the low pressure spool created in Phase I with the high pressure spool, which is based on Capstone’s C65 (65 kW) commercially available engine. Integration of the engines, based on preliminary research, would allow the dual spool engine to provide electrical power in excess of 370 kW, with electrical efficiency approaching 42%. If both of these targets were met coupled with the overall CHP target of 85% total combined heating and electrical efficiency California Air Resources Board (CARB) level emissions, and a price target of $600 per kW, the system would represent a step change in the currently available commercial generation technology. Phase I of the C370 program required the development of the C370 low pressure spool. The goal was to increase the C200 engine power by a minimum of 25% — 250 kW — and efficiency from 32% to 37%. These increases in the C200 engine output were imperative to meet the power requirements of the engine when both spools were integrated. An additional benefit of designing and testing the C370 low pressure spool was the possibility of developing a stand-alone product for possible

  8. High efficiency 4H-SiC betavoltaic power sources using tritium radioisotopes

    SciTech Connect

    Thomas, Christopher; Portnoff, Samuel; Spencer, M. G.

    2016-01-04

    Realization of an 18.6% efficient 4H-silicon carbide (4H-SiC) large area betavoltaic power source using the radioisotope tritium is reported. A 200 nm 4H-SiC P{sup +}N junction is used to collect high-energy electrons. The electron source is a titanium tritide (TiH{sup 3}{sub x}) foil, or an integrated titanium tritide region formed by the diffusion of tritium into titanium. The specific activity of the source is directly measured. Dark current measured under short circuit conditions was less than 6.1 pA/cm{sup 2}. Samples measured with an external tritium foil produced an open circuit voltage of 2.09 V, short circuit current of 75.47 nA/cm{sup 2}, fill factor of 0.86, and power efficiency of 18.6%. Samples measured with an integrated source produced power efficiencies of 12%. Simulations were done to determine the beta spectrum (modified by self absorption) exiting the source and the electron hole pair generation function in the 4H-SiC. The electron-hole pair generation function in 4H-SiC was modeled as a Gaussian distribution, and a closed form solution of the continuity equation was used to analyze the cell performance. The effective surface recombination velocity in our samples was found to be 10{sup 5}–10{sup 6 }cm/s. Our analysis demonstrated that the surface recombination dominates the performance of a tritium betavoltaic device but that using a thin P{sup +}N junction structure can mitigate some of the negative effects.

  9. Structure of 100 W high-efficiency piezoelectric transformer for applications in power electronics

    NASA Astrophysics Data System (ADS)

    Suzuki, Kohei; Adachi, Kazunari; Shibamata, Yuki; Suzuki, Tsunehisa

    2016-08-01

    We propose a piezoelectric transformer comprising two identical bolt-clamped Langevin-type transducers (BLTs) and a stepped horn for its applications to high-power electronics. The transformer can realize a specified step-up voltage transformation ratio determined by the cross-sectional area ratio of the horn, both ends of which are connected to the BLTs, at a driving frequency in the vicinity of its mechanical resonance frequency. In experiments, we obtained the results predicted by finite-element analysis. The deviations of the measured resonance and driving frequencies from the numerically estimated values were 0.86 and 0.80%, respectively. At the driving frequency, the maximum efficiency was 99.2%, and a maximum output power of 100 W was obtained with an input voltage of 100 Vrms. Nevertheless, we observed unstable actions of the transformer, which can be attributed to the “jumping and dropping” phenomena, in high voltage operation. Numerical analysis suggests that the instability may be caused by the local electric field concentration in the piezoelectric elements, which occurs only when the transformer is driven by a low-output-impedance voltage source at its mechanical resonance frequency.

  10. High-efficiency power production from natural gas with carbon capture

    NASA Astrophysics Data System (ADS)

    Adams, Thomas A.; Barton, Paul I.

    A unique electricity generation process uses natural gas and solid oxide fuel cells at high electrical efficiency (74%HHV) and zero atmospheric emissions. The process contains a steam reformer heat-integrated with the fuel cells to provide the heat necessary for reforming. The fuel cells are powered with H 2 and avoid carbon deposition issues. 100% CO 2 capture is achieved downstream of the fuel cells with very little energy penalty using a multi-stage flash cascade process, where high-purity water is produced as a side product. Alternative reforming techniques such as CO 2 reforming, autothermal reforming, and partial oxidation are considered. The capital and energy costs of the proposed process are considered to determine the levelized cost of electricity, which is low when compared to other similar carbon capture-enabled processes.

  11. Device and Design Optimization for AlGaN/GaN X-Band-Power-Amplifiers with High Efficiency

    NASA Astrophysics Data System (ADS)

    Kühn, Jutta; van Raay, Friedbert; Quay, Rüdiger; Kiefer, Rudolf; Mikulla, Michael; Seelmann-Eggebert, Matthias; Bronner, Wolfgang; Schlechtweg, Michael; Ambacher, Oliver; Thumm, Manfred

    2010-03-01

    The design, realization and characterization of dual-stage X-band high-power and highly-efficient monolithic microwave integrated circuit (MMIC) power amplifiers (PAs) with AlGaN/GaN high electronic mobility transistors (HEMTs) is presented. These high power amplifiers (HPAs) are based on a precise investigation of circuit-relevant HEMT behavior using two different field-plate variants and its effects on PA performance as well as optimization of HPA driver stage size which also has a deep impact on the entire HPA. Two broadband (3 GHz) MMICs with different field-plate variants and two narrowband (1 GHz) PAs with different driver- to final-stage gate-width ratio are realized with a maximum output power of 19-23 W, a maximum power-added efficiency (PAE) of ≥40%, and an associated power gain of 17 dB at X-band. Furthermore, two 1 mm test transistors of the same technology with the mentioned field-plate variants and a 1 mm test MMIC support VSWR-ratio tests of 6:1 and 4:1, respectively.

  12. High-power and highly efficient operation of wavelength-tunable Raman fiber lasers based on volume Bragg gratings.

    PubMed

    Liu, Jun; Shen, Deyuan; Huang, Haitao; Zhao, Chujun; Zhang, Xiaoqi; Fan, Dianyuan

    2014-03-24

    Highly efficient and high-power operation of Raman fiber lasers in fixed-wavelength and wavelength-tunable cavity configurations based on a graded-index multimode fiber is reported. Fixed-wavelength and wavelength tunable operating regimes are achieved using volume Bragg gratings (VBGs) with center wavelengths of 1658 nm and 1750 nm, respectively. The fixed-wavelength laser yielded a maximum output power of 10.5 W at 1658.3 nm with a FWHM linewidth of ~0.1 nm for the launched pump power of 23.4 W, corresponding to a slope efficiency of 82.7% with respect to the launched pump power. The measured beam quality in the form of M² factor is ~1.35, corresponding to the fundamental mode of the fiber. For the wavelength-tunable Raman fiber laser, a wavelength tuning range of 37 nm from 1638.5 to 1675.1 nm is obtained with a maximum output power of 3.6 W at 1658.5 nm for the launched pump power of 13.0 W.

  13. Spectral splitting optimization for high-efficiency solar photovoltaic and thermal power generation

    NASA Astrophysics Data System (ADS)

    Bierman, David M.; Lenert, Andrej; Wang, Evelyn N.

    2016-12-01

    Utilizing the full solar spectrum is desirable to enhance the conversion efficiency of a solar power generator. In practice, this can be achieved through spectral splitting between multiple converters in parallel. However, it is unclear which wavelength bands should be directed to each converter in order to maximize the efficiency. We developed a model of an ideal hybrid solar converter which utilizes both a single-junction photovoltaic cell and a thermal engine. We determined the limiting efficiencies of this hybrid strategy and the corresponding optimum spectral bandwidth directed to the photovoltaic cell. This optimum width is inversely proportional to the thermal engine efficiency and scales with the bandgap of the photovoltaic cell. This bandwidth was also obtained analytically through an entropy minimization scheme and matches well with our model. We show that the maximum efficiency of the system occurs when it minimizes the spectral entropy generation. This concept can be extended to capture generalized non-idealities to increase the usefulness of this technique for a range of full solar spectrum utilization technologies.

  14. High-efficiency concentration/multi-solar-cell system for orbital power generation

    NASA Technical Reports Server (NTRS)

    Onffroy, J. R.; Stoltzmann, D. E.; Lin, R. J. H.; Knowles, G. R.

    1980-01-01

    An analysis was performed to determine the economic feasibility of a concentrating spectrophotovoltaic orbital electrical power generation system. In this system dichroic beam-splitting mirrors are used to divide the solar spectrum into several wavebands. Absorption of these wavebands by solar cells with matched energy bandgaps increases the cell efficiency while decreasing the amount of heat which must be rejected. The optical concentration is performed in two stages. The first concentration stage employs a Cassegrain-type telescope, resulting in a short system length. The output from this stage is directed to compound parabolic concentrators which comprise the second stage of concentration. Ideal efficiencies for one-, two-, three-, and four-cell systems were calculated under 1000 sun, AMO conditions, and optimum energy bands were determined. Realistic efficiencies were calculated for various combinations of Si, GaAs, Ge and GaP. Efficiencies of 32 to 33 percent were obtained with the multicell systems. The optimum system consists of an f/3.5 optical system, a beam splitter to divide the spectrum at 0.9 microns, and two solar cell arrays, GaAs and Si.

  15. Editorially Speaking - Fusion Power: Reasons for Higher Priority

    ERIC Educational Resources Information Center

    Lippincott, William T.

    1973-01-01

    Discusses current research trends in the use of laser-fusion technology in combustion chambers to eradicate energy shortages. Indicates that fusion power could be made available at a relatively low expense. (CC)

  16. High-efficiency ordered silicon nano-conical-frustum array solar cells by self-powered parallel electron lithography.

    PubMed

    Lu, Yuerui; Lal, Amit

    2010-11-10

    Nanostructured silicon thin film solar cells are promising, due to the strongly enhanced light trapping, high carrier collection efficiency, and potential low cost. Ordered nanostructure arrays, with large-area controllable spacing, orientation, and size, are critical for reliable light-trapping and high-efficiency solar cells. Available top-down lithography approaches to fabricate large-area ordered nanostructure arrays are challenging due to the requirement of both high lithography resolution and high throughput. Here, a novel ordered silicon nano-conical-frustum array structure, exhibiting an impressive absorbance of 99% (upper bound) over wavelengths 400-1100 nm by a thickness of only 5 μm, is realized by our recently reported technique self-powered parallel electron lithography that has high-throughput and sub-35-nm high resolution. Moreover, high-efficiency (up to 10.8%) solar cells are demonstrated, using these ordered ultrathin silicon nano-conical-frustum arrays. These related fabrication techniques can also be transferred to low-cost substrate solar energy harvesting device applications.

  17. The high-efficiency jets magnetically accelerated from a thin disk in powerful lobe-dominated FRII radio galaxies

    SciTech Connect

    Li, Shuang-Liang

    2014-06-10

    A maximum jet efficiency line R ∼ 25 (R = L {sub jet}/L {sub bol}), found in FRII radio galaxies by Fernandes et al., was extended to cover the full range of jet power by Punsly. Recent general relativistic magnetohydrodynamic simulations of jet formation have mainly focused on the enhancement of jet power. In this work, we suggest that the jet efficiency could be very high even for conventional jet power if the radiative efficiency of disks was much smaller. We adopt the model of a thin disk with magnetically driven winds to investigate the observational high-efficiency jets in FRII radio galaxies. It is found that the structure of a thin disk can be significantly altered by the feedback of winds. The temperature of a disk gradually decreases with increasing magnetic field; the disk density, surface density, and pressure also change enormously. The lower temperature and higher surface density in the inner disk result in the rapid decrease of radiative efficiency. Thus, the jet efficiency is greatly improved even if the jet power is conventional. Our results can explain the observations quite well. The theoretical maximum jet efficiency of R ∼ 1000 suggested by our calculations is large enough to explain all of the high jet efficiency in observations, even considering the episodic activity of jets.

  18. Alternate applications of fusion power: development of a high-temperature blanket for synthetic-fuel production

    SciTech Connect

    Howard, P.A.; Mattas, R.F.; Krajcinovic, D.; DePaz, J.; Gohar, Y.

    1981-11-01

    This study has shown that utilization of the unique features of a fusion reactor can result in a novel and potentially economical method of decomposing steam into hydrogen and oxygen. Most of the power of fusion reactors is in the form of energetic neutrons. If this power could be used to produce high temperature uncontaminated steam, a large fraction of the energy needed to decomposee the steam could be supplied as thermal energy by the fusion reaction. Proposed high temperature electrolysis processes require steam temperature in excess of 1000/sup 0/C for high efficiency. The design put forth in this study details a system that can accomplish that end.

  19. A commercial lunar helium 3 fusion power infrasructure

    NASA Astrophysics Data System (ADS)

    Sved, J.; Kulcinski, G. L.; Miley, G. H.

    1995-01-01

    The potential scenario of a commercial aneutronic fusion power economy based on Helium 3 is reviewed with recent developments in fusion grade plasma containment considered. The Spherical Inertial Electrostatic Confinement (IEC) device is a type of fusion reactor with immediate commercial applications as a small non-power reactor. Further development and growth to power reactor fusion reaction rates using Deuterium and Helium 3 offers the potential practical solution to fusion power. Recovery of the lunar Helium 3 inventory for export to power utility customers will require the build-up of a cis-lunar industrial infrastructure. Space transport capacity will be obliged to grow rapidly to support several thousand tons of cargo delivery to the lunar surface per year. A highly reusable, low operations cost cis-lunar transport infrastructure and lunar surface industrial activity will be made more practical by the availability of IEC fusion power units that are intrinsically low mass and compatible with space transport.

  20. Introduction to Nuclear Fusion Power and the Design of Fusion Reactors. An Issue-Oriented Module.

    ERIC Educational Resources Information Center

    Fillo, J. A.

    This three-part module focuses on the principles of nuclear fusion and on the likely nature and components of a controlled-fusion power reactor. The physical conditions for a net energy release from fusion and two approaches (magnetic and inertial confinement) which are being developed to achieve this goal are described. Safety issues associated…

  1. Inertial fusion power for space applications

    SciTech Connect

    Meier, W.R.; Hogan, W.J.; Hoffman, N.J.; Murray, K.A.; Olson, R.E.

    1986-05-19

    More than thirty-seven design concepts have been proposed for terrestrial ICF power plants. The design space is large because of the many allowable driver and reaction chamber combinations. These design studies have illustrated advantages of ICF power plants over other sources in lower impact on the environment, high safety, and almost no dependence on consumables like fuel. The fact that, once built, a 1000 MW/sub e/ ICF power plant would require only 240 kg of deuterium and from 770 to 9260 kg of lithium to run for five years (at 70% capacity factor) makes it potentially attractive for space power also. However, the designs proposed to date have emphasized features that would make the plant attractive for terrestrial applications, where economics, efficiency, and environmental considerations dominate. The resulting plants are large and contain many very heavy components that would not be at attractive for space applications. In this paper, we evaluate alternative ICF driver and reactor technologies using space application criteria and also discuss how some of those technologies can be altered to produce smaller, lighter fusion power sources for space.

  2. Explosive pulse power for fusion applications

    NASA Astrophysics Data System (ADS)

    Reinovsky, R. E.; Lindemuth, I. R.; Marsh, S. P.; Lopez, E. A.

    Explosive pulse power systems, powered by flux compression generators and including a variety of high current power conditioning components, such as high current opening switches, are attractive for powering fusion physics experiments which require 10's MJ of electrical energy. Such systems are economical when compared to other high energy sources and require little capital investment to enable initial experiments. They are flexible and readily reconfigurable to accommodate changing experimental requirements and can be designed, assembled, and fielded in relatively short periods of time. Several configurations of very high energy flux compressors have been explored at Los Alamos and recently Russian researchers at the All Russian Institute of Experimental Physics (VNIIEF) have reported notable results from modular systems based on disk concepts. A phenomenological model of disk flux compressors is described. The performance predicted by these models is in sufficiently good agreement with the results reported by VNIIEF researchers to allow the model to be applied, in the future, to the design of power conditions systems for use in conjunction with these high performance generators.

  3. High efficient photovoltaic power converter suitable for 920nm to 970nm InGaAs laser diodes

    NASA Astrophysics Data System (ADS)

    Liu, James; Wu, Ta-Chung; Cohen, Mort; Werthen, Jan G.

    2005-09-01

    In this work, we report a highly efficient Photovoltaic Power Converter (PPC) suitable for 920 nm to 970 nm InGaAs MQW lasers for the first time. The epitaxial layers were grown by low pressure MOCVD on the semi-insulting GaAs substrate. The epi layers consist of a p-n junction of In0.12Ga0.88As and the window layer of p+ AlInGaAs. The device is made of seven or eight pie-segments of equal area series-connected by means of air-bridges. Under 500mW of 940nm laser illumination, the open-circuit voltage of the eight-segment InGaAs chip is 6.7V. The short-circuit current is 29.7mA. Its maximum delivered electrical power is 171.2mW, equal to a 34.2% overall power conversion efficiency. We also demonstrate the high temperature characteristic and stability of the device.

  4. High efficient ultrahigh acceleration of plasma blocks by PW-ps laser pulses for producing fusion flames in DT and HB11 of solid state density

    NASA Astrophysics Data System (ADS)

    Moustaizis, S.; Lalousis, P.; Hora, H.; Miley, G. H.

    2016-03-01

    Ultrahigh acceleration of plasma blocks in the range of 1020 cm/s2 has been confirmed experimentally after this was long predicted as a non-thermal direct conversion of optical energy into plasma motion due to dominating nonlinear (ponderomotive) forces [1]. The use of laser pulses of more than PW power and ps or shorter duration can ignite a nuclear fusion flame in solid density deuterium tritium because the necessary energy flux of >108J/cm2 according to the theory of Chu [2] is available [3]. For the studies of the necessary velocities of the generated fusion flames above 1000 km/s the detailed processes can be analyzed by using the advanced genuine two-fluid hydrodynamic model [4] where it was surprising that the ignition of the fusion flame by the picosecond interaction needs a comparably long development in the nanosecond range before the thermal processes result in shock fronts similar to the Rakine-Hugoniot theory. For the evaluation of power generation the problem of lateral energy losses was studied by using very high pulsed magnetic fields. The recently produced 10 Kilotesla magnetic fields [5] are very promising for solutions.

  5. Fusion Power Program biannual progress report, April-September 1979

    SciTech Connect

    Not Available

    1980-02-01

    This biannual report summarizes the Argonne National Laboratory work performed for the Office of Fusion Energy during the April-September 1979 quarter in the following research and development areas: materials; energy storage and transfer; tritium containment, recovery and control; advanced reactor design; atomic data; reactor safety; fusion-fission hybrid systems; alternate applications of fusion energy; and other work related to fusion power. Separate abstracts were prepared for three sections. (MOW)

  6. Fusion-power demonstration. [Next step beyond MFTF-B

    SciTech Connect

    Henning, C.D.; Logan, B.G.; Carlson, G.A.; Neef, W.S.; Moir, R.W.; Campbell, R.B.; Botwin, R.; Clarkson, I.R.; Carpenter, T.J.

    1983-03-29

    As a satellite to the MARS (Mirror Advanced Reactor Study) a smaller, near-term device has been scoped, called the FPD (Fusion Power Demonstration). Envisioned as the next logical step toward a power reactor, it would advance the mirror fusion program beyond MFTF-B and provide an intermediate step toward commercial fusion power. Breakeven net electric power capability would be the goal such that no net utility power would be required to sustain the operation. A phased implementation is envisioned, with a deuterium checkout first to verify the plasma systems before significant neutron activation has occurred. Major tritium-related facilities would be installed with the second phase to produce sufficient fusion power to supply the recirculating power to maintain the neutral beams, ECRH, magnets and other auxiliary equipment.

  7. High Efficiency Automatic-Power-Controlled and Gain-Clamped EDFA for Broadband Passive Optical Networking Systems

    NASA Astrophysics Data System (ADS)

    Shen, Jyi-Lai; Wei, Shui-Ken; Lin, Chin-Yuan; Iong Li, Ssu; Huang, Chih-Chuan

    2010-04-01

    The configuration of a simple improved high efficiency automatic-power-controlled and gain-clamped EDFA (APC-GC-EDFA) for broadband passive optical networking systems (BPON) is presented here. In order to compensate the phase and amplitude variation due to the different distance between the optical line terminal (OLT) and optical network units (ONU), the APC-GC-EDFA need to be employed. A single 980 nm laser module is employed as the primary pump. To extend the bandwidth, all C-band ASE is recycled as the secondary pump to enhance the gain efficiency. An electrical feedback circuit is used as a multi-wavelength channel transmitter monitor for the automatic power control to improve the gain-flattened flatness for stable amplification. The experimental results prove that the EDFA system can provide flatter clamped gain in both C-band and L-band configurations. The gain flatness wavelength ranging from 1530 to 1610 nm is within 32.83 ± 0.64 dB, i.e. below 1.95 %. The gains are clamped at 33.85 ± 0.65 dB for the input signal power of -40 dBm to -10 dBm. The range of noise figure is between 6.37 and 6.56, which is slightly lower compared to that of unclamped amplifiers. This will be very useful for measuring the gain flatness of APC-GC-EDFA. Finally, we have also demonstrated the records of the overall simultaneous dynamics measurements for the new system stabilization. The carrier to noise ratio (CNR) is 49.5 to 50.8 dBc which is above the National Television System Committee (NTSC) standard of 43 dBc, and both composite second order (CSO) 69.2 to 71.5 dBc and composite triple beat (CTB) of 69.8 to 72.2 dBc are above 53 dBc. The recorded corresponding rise-time of 1.087 ms indicates that the system does not exhibit any overshoot of gain or ASE variation due to the signal at the beginning of the pulse.

  8. Fusion Power Demonstrations I and II

    SciTech Connect

    Doggett, J.N.

    1985-01-01

    In this report we present a summary of the first phase of the Fusion Power Demonstration (FPD) design study. During this first phase, we investigated two configurations, performed detailed studies of major components, and identified and examined critical issues. In addition to these design specific studies, we also assembled a mirror-systems computer code to help optimize future device designs. The two configurations that we have studied are based on the MARS magnet configuration and are labeled FPD-I and FPD-II. The FPD-I configuration employs the same magnet set used in the FY83 FPD study, whereas the FPD-II magnets are a new, much smaller set chosen to help reduce the capital cost of the system. As part of the FPD study, we also identified and explored issues critical to the construction of an Engineering Test Reactor (ETR). These issues involve subsystems or components, which because of their cost or state of technology can have a significant impact on our ability to meet FPD's mission requirements on the assumed schedule. General Dynamics and Grumman Aerospace studied two of these systems, the high-field choke coil and the halo pump/direct converter, in great detail and their findings are presented in this report.

  9. Modular control of fusion power heating applications

    SciTech Connect

    Demers, D. R.

    2012-08-24

    This work is motivated by the growing demand for auxiliary heating on small and large machines worldwide. Numerous present and planned RF experiments (EBW, Lower Hybrid, ICRF, and ECH) are increasingly complex systems. The operational challenges are indicative of a need for components of real-time control that can be implemented with a moderate amount of effort in a time- and cost-effective fashion. Such a system will improve experimental efficiency, enhance experimental quality, and expedite technological advancements. The modular architecture of this control-suite serves multiple purposes. It facilitates construction on various scales from single to multiple controller systems. It enables expandability of control from basic to complex via the addition of modules with varying functionalities. It simplifies the control implementation process by reducing layers of software and electronic development. While conceived with fusion applications in mind, this suite has the potential to serve a broad range of scientific and industrial applications. During the Phase-I research effort we established the overall feasibility of this modular control-suite concept. We developed the fundamental modules needed to implement open-loop active-control and demonstrated their use on a microwave power deposition experiment.

  10. Advances in Tandem Mirror fusion power reactors

    SciTech Connect

    Perkins, L.J.; Logan, B.G.

    1986-05-20

    The Tandem Mirror exhibits several distinctive features which make the reactor embodiment of the principle very attractive: Simple low-technology linear central cell; steady-state operation; high-..beta.. operation; no driven current or disruptions; divertorless operation; direction conversion of end-loss power; low-surface heat loads; and advanced fusion fuel capability. In this paper, we examine these features in connection with two tandem mirror reactor designs, MARS and MINIMARS, and several advanced reactor concepts including the wall-stabilized reactor and the field-reversed mirror. With a novel compact end plug scheme employing octopole stabilization, MINIMARS is expressly designed for short construction times, factory-built modules, and a small (600 MWe) but economic reactor size. We have also configured the design for low radioactive afterheat and inherent/passive safety under LOCA/LOFA conditions, thereby obviating the need for expensive engineered safety systems. In contrast to the complex and expensive double-quadrupole end-cell of the MARS reactor, the compact octopole end-cell of MINIMARS enables ignition to be achieved with much shorter central cell lengths and considerably improves the economy of scale for small (approx.250 to 600 MWe) tandem mirror reactors. Finally, we examine the prospects for realizing the ultimate potential of the tandem mirror with regard to both innovative configurations and novel neutron energy conversion schemes, and stress that advanced fuel applications could exploit its unique reactor features.

  11. Inertial Fusion Power Plant Concept of Operations and Maintenance

    SciTech Connect

    Anklam, T.; Knutson, B.; Dunne, A. M.; Kasper, J.; Sheehan, T.; Lang, D.; Roberts, V.; Mau, D.

    2015-01-15

    Parsons and LLNL scientists and engineers performed design and engineering work for power plant pre-conceptual designs based on the anticipated laser fusion demonstrations at the National Ignition Facility (NIF). Work included identifying concepts of operations and maintenance (O&M) and associated requirements relevant to fusion power plant systems analysis. A laser fusion power plant would incorporate a large process and power conversion facility with a laser system and fusion engine serving as the heat source, based in part on some of the systems and technologies advanced at NIF. Process operations would be similar in scope to those used in chemical, oil refinery, and nuclear waste processing facilities, while power conversion operations would be similar to those used in commercial thermal power plants. While some aspects of the tritium fuel cycle can be based on existing technologies, many aspects of a laser fusion power plant presents several important and unique O&M requirements that demand new solutions. For example, onsite recovery of tritium; unique remote material handling systems for use in areas with high radiation, radioactive materials, or high temperatures; a five-year fusion engine target chamber replacement cycle with other annual and multi-year cycles anticipated for major maintenance of other systems, structures, and components (SSC); and unique SSC for fusion target waste recycling streams. This paper describes fusion power plant O&M concepts and requirements, how O&M requirements could be met in design, and how basic organizational and planning issues can be addressed for a safe, reliable, economic, and feasible fusion power plant.

  12. Inertial fusion power plant concept of operations and maintenance

    NASA Astrophysics Data System (ADS)

    Knutson, Brad; Dunne, Mike; Kasper, Jack; Sheehan, Timothy; Lang, Dwight; Anklam, Tom; Roberts, Valerie; Mau, Derek

    2015-02-01

    Parsons and LLNL scientists and engineers performed design and engineering work for power plant pre-conceptual designs based on the anticipated laser fusion demonstrations at the National Ignition Facility (NIF). Work included identifying concepts of operations and maintenance (O&M) and associated requirements relevant to fusion power plant systems analysis. A laser fusion power plant would incorporate a large process and power conversion facility with a laser system and fusion engine serving as the heat source, based in part on some of the systems and technologies advanced at NIF. Process operations would be similar in scope to those used in chemical, oil refinery, and nuclear waste processing facilities, while power conversion operations would be similar to those used in commercial thermal power plants. While some aspects of the tritium fuel cycle can be based on existing technologies, many aspects of a laser fusion power plant presents several important and unique O&M requirements that demand new solutions. For example, onsite recovery of tritium; unique remote material handling systems for use in areas with high radiation, radioactive materials, or high temperatures; a five-year fusion engine target chamber replacement cycle with other annual and multi-year cycles anticipated for major maintenance of other systems, structures, and components (SSC); and unique SSC for fusion target waste recycling streams. This paper describes fusion power plant O&M concepts and requirements, how O&M requirements could be met in design, and how basic organizational and planning issues can be addressed for a safe, reliable, economic, and feasible fusion power plant.

  13. Fusion Breeding for Sustainable, Mid Century, Carbon Free Power

    NASA Astrophysics Data System (ADS)

    Manheimer, Wallace

    2015-11-01

    If ITER achieves Q ~10, it is still very far from useful fusion. The fusion power, and the driver power will allow only a small amount of power to be delivered, <~50MW for an ITER scale tokamak. It is unlikely, considering ``conservative design rules'' that tokamaks can ever be economical pure fusion power producers. Considering the status of other magnetic fusion concepts, it is also very unlikely that any alternate concept will either. Laser fusion does not seem to be constrained by any conservative design rules, but considering the failure of NIF to achhieve ignition, at this point it has many more obstacles to overcome than magnetic fusion. One way out of this dilemma is to use an ITER size tokamak, or a NIF size laser, as a fuel breeder for searate nuclear reactors. Hence ITER and NIF become ends in themselves, instead of steps to who knows what DEMO decades later. Such a tokamak can easily live within the consrtaints of conservative design rules. This has led the author to propose ``The Energy Park'' a sustainable, carbon free, economical, and environmently viable power source without prolifertion risk. It is one fusion breeder fuels 5 conventional nuclear reactors, and one fast neutron reactor burns the actinide wastes.

  14. Programmable AC power supply for simulating power transient expected in fusion reactor

    SciTech Connect

    Halimi, B.; Suh, K. Y.

    2012-07-01

    This paper focus on control engineering of the programmable AC power source which has capability to simulate power transient expected in fusion reactor. To generate the programmable power source, AC-AC power electronics converter is adopted to control the power of a set of heaters to represent the transient phenomena of heat exchangers or heat sources of a fusion reactor. The International Thermonuclear Experimental Reactor (ITER) plasma operation scenario is used as the basic reference for producing this transient power source. (authors)

  15. The neutronics studies of fusion fission hybrid power reactor

    SciTech Connect

    Zheng Youqi; Wu Hongchun; Zu Tiejun; Yang Chao; Cao Liangzhi

    2012-06-19

    In this paper, a series of neutronics analysis of hybrid power reactor is proposed. The ideas of loading different fuels in a modular-type fission blanket is analyzed, fitting different level of fusion developments, i.e., the current experimental power output, the level can be obtained in the coming future and the high-power fusion reactor like ITER. The energy multiplication of fission blankets and tritium breeding ratio are evaluated as the criterion of design. The analysis is implemented based on the D-type simplified model, aiming to find a feasible 1000MWe hybrid power reactor for 5 years' lifetime. Three patterns are analyzed: 1) for the low fusion power, the reprocessed fuel is chosen. The fuel with high plutonium content is loaded to achieve large energy multiplication. 2) For the middle fusion power, the spent fuel from PWRs can be used to realize about 30 times energy multiplication. 3) For the high fusion power, the natural uranium can be directly used and about 10 times energy multiplication can be achieved.

  16. High-efficiency grid-connected photovoltaic module integrated converter system with high-speed communication interfaces for small-scale distribution power generation

    SciTech Connect

    Choi, Woo-Young; Lai, Jih-Sheng

    2010-04-15

    This paper presents a high-efficiency grid-connected photovoltaic (PV) module integrated converter (MIC) system with reduced PV current variation. The proposed PV MIC system consists of a high-efficiency step-up DC-DC converter and a single-phase full-bridge DC-AC inverter. An active-clamping flyback converter with a voltage-doubler rectifier is proposed for the step-up DC-DC converter. The proposed step-up DC-DC converter reduces the switching losses by eliminating the reverse-recovery current of the output rectifying diodes. To reduce the PV current variation introduced by the grid-connected inverter, a PV current variation reduction method is also suggested. The suggested PV current variation reduction method reduces the PV current variation without any additional components. Moreover, for centralized power control of distributed PV MIC systems, a PV power control scheme with both a central control level and a local control level is presented. The central PV power control level controls the whole power production by sending out reference power signals to each individual PV MIC system. The proposed step-up DC-DC converter achieves a high-efficiency of 97.5% at 260 W output power to generate the DC-link voltage of 350 V from the PV voltage of 36.1 V. The PV MIC system including the DC-DC converter and the DC-AC inverter achieves a high-efficiency of 95% with the PV current ripple less than 3% variation of the rated PV current. (author)

  17. Integrated systems for pulsed-power driven inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Cuneo, M. E.; Slutz, S. A.; Stygar, W. A.; Herrmann, M. C.; Sinars, D. B.; McBride, R. D.; Vesey, R. A.; Sefkow, A. B.; Mazarakis, M. G.; Vandevender, J. P.; Waisman, E. M.; Hansen, D. L.; Owen, A. C.; Jones, J. F.; Romero, J. A.; McKenney, J.

    2011-10-01

    Pulsed power fusion concepts integrate: (i) directly-magnetically-driven fusion targets that absorb large energies (10 MJ), (ii) efficient, rep-rated driver modules, (iii) compact, scalable, integrated driver architectures, (iv) driver-to-target coupling techniques with standoff and driver protection, and (v) long lifetime fusion chambers shielded by vaporizing blankets and thick liquid walls. Large fusion yields (3-30 GJ) and low rep-rates (0.1-1 Hz) may be an attractive path for IFE. Experiments on the ZR facility are validating physics issues for magnetically driven targets. Scientific breakeven (fusion energy = fuel energy) may be possible in the next few years. Plans for system development and integration will be discussed. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  18. High power millimeter wave ECRH source needs for fusion program

    SciTech Connect

    Not Available

    1984-06-01

    This document stems from the four-day Gyrotron Symposium held at the US Department of Energy (DOE) Headquarters on June 13-16, 1983, and serves as a position paper for the Office of Fusion Energy, DOE, on high-power millimeter wave source development for Electron Cyclotron Heating (ECH) of plasmas. It describes the fusion program needs for gyrotron as ECH sources, their current status, and desirable development strategies.

  19. Progress in GaAs Metamorphic HEMT Technology for Microwave Applications. High Efficiency Ka-Band MHEMT Power MMICs

    NASA Technical Reports Server (NTRS)

    Smith, P. M.; Dugas, D.; Chu, K.; Nichols, K.; Duh, K. H.; Fisher, J.; MtPleasant, L.; Xu, D.; Gunter, L.; Vera, A.

    2003-01-01

    This paper reviews recent progress in the development of GaAs metamorphic HEMT (MHEMT) technology for microwave applications. Commercialization has begun, while efforts to further improve performance, manufacturability and reliability continue. We also report the first multi-watt MHEMT MMIC power amplifiers, demonstrating up to 3.2W output power and record power-added efficiency (PAE) at Ka-band.

  20. 975 nm high power diode lasers with high efficiency and narrow vertical far field enabled by low index quantum barriers

    NASA Astrophysics Data System (ADS)

    Crump, P.; Pietrzak, A.; Bugge, F.; Wenzel, H.; Erbert, G.; Tränkle, G.

    2010-03-01

    For optimal coupled power into fiber, high power diode lasers should operate efficiently with smallest possible vertical far field emission angle. Although waveguide and cladding layers can be designed to achieve small angles, the refractive index profile of the active region itself restricts the minimum achievable value. We show that the use of low index quantum barrier layers leads to substantially reduced far field angles, while sustaining high power conversion efficiency. 90 μm stripe lasers that use such designs have narrow vertical far field angles of 30° (95% power content), power conversion efficiency of 58% and operate reliably at 10 W output.

  1. Inertial fusion with ultra-powerful lasers

    SciTech Connect

    Tabak, M.; Hammer, J.; Glinsky, M.; Kruer, W.; Wilks, S.; Woodworth, J.; Campbell, E.M.; Perry, M.D.; Mason, R.

    1993-10-01

    Ultra-high intensity lasers can be used to ignite ICF capsules with a few tens of kilojoules of light and can lead to high gain with as little as 100 kilojoules of incident laser light. We propose a scheme with three phases. First, a capsule is imploded as in the conventional approach to inertial fusion to assemble a high density fuel configuration. Second, a hole is bored through capsule corona composed of ablated material, pushing critical density close to the high density core of the capsule, by employing the ponderomotive force associated with high intensity laser light. Finally, the fuel is ignited by suprathermal electrons, produced in the high intensity laser plasma interactions, which propagate from critical density to this high density core. This paper reviews two models of energy gain in ICF capsules and explains why ultra-high intensity lasers allow access to the model producing the higher gains. This new scheme also drastically reduces the difficulty of the implosion and thereby allows lower quality fabrication and less stringent beam quality and symmetry requirements from the implosion driver. The difficulty of the fusion scheme is transferred to the technological difficulty of producing the ultra-high-intensity laser and of transporting this energy to the fuel.

  2. Progress in the pulsed power Inertial Confinement Fusion program

    SciTech Connect

    Quintenz, J.P.; Matzen, M.K.; Mehlhorn, T.A.

    1996-12-01

    Pulsed power accelerators are being used in Inertial Confinement Fusion (ICF) research. In order to achieve our goal of a fusion yield in the range of 200 - 1000 MJ from radiation-driven fusion capsules, it is generally believed that {approx}10 MJ of driver energy must be deposited within the ICF target in order to deposit {approx}1 MJ of radiation energy in the fusion capsule. Pulsed power represents an efficient technology for producing both these energies and these radiation environments in the required short pulses (few tens of ns). Two possible approaches are being developed to utilize pulsed power accelerators in this effort: intense beams of light ions and z- pinches. This paper describes recent progress in both approaches. Over the past several years, experiments have successfully answered many questions critical to ion target design. Increasing the ion beam power and intensity are our next objectives. Last year, the Particle Beam Fusion Accelerator H (PBFA II) was modified to generate ion beams in a geometry that will be required for high yield applications. This 2048 modification has resulted in the production of the highest power ion beam to be accelerated from an extraction ion diode. We are also evaluating fast magnetically-driven implosions (z-pinches) as platforms for ICF ablator physics and EOS experiments. Z-pinch implosions driven by the 20 TW Saturn accelerator have efficiently produced high x- ray power (> 75 TW) and energy (> 400 kJ). Containing these x-ray sources within a hohlraum produces a unique large volume (> 6000 mm{sup 3}), long lived (>20 ns) radiation environment. In addition to studying fundamental ICF capsule physics, there are several concepts for driving ICF capsules with these x-ray sources. Progress in increasing the x-ray power on the Saturn accelerator and promise of further increases on the higher power PBFA II accelerator will be described.

  3. Design of an Ultra-High Efficiency GaN High-Power Amplifier for SAR Remote Sensing

    NASA Technical Reports Server (NTRS)

    Thrivikraman, Tushar; Hoffman, James

    2013-01-01

    This work describes the development of a high-power amplifier for use with a remote sensing SAR system. The amplifier is intended to meet the requirements for the Sweep-SAR technique for use in the proposed DESDynI SAR instrument. In order to optimize the amplifier design, active load-pull technique is employed to provide harmonic tuning to provide efficiency improvements. In addition, some of the techniques to overcome the challenges of load-pulling high power devices are presented. The design amplifier was measured to have 49 dBm of output power with 75% PAE, which is suitable to meet the proposed system requirements.

  4. High-power and highly efficient Tm3+-doped silica fiber lasers pumped with diode lasers operating at 1150 nm.

    PubMed

    Jackson, Stuart D; Bugge, Frank; Erbert, Götz

    2007-10-01

    An output power of 1.74 W at 2.03 microm was generated at a slope efficiency of 51% when a double-clad Tm(3+)-doped silica fiber laser was pumped with high-power 1150 nm diode lasers. Pump excited state absorption from the upper laser level populates higher energy levels allowing cross relaxation to repopulate the upper laser level at a quantum efficiency greater than unity and to limit losses relating to additional pump excited state absorption. The output power was scaled to 4.77 W when both ends of the fiber were pumped.

  5. High-Efficiency Expression of TAT-bFGF Fusion Protein in Escherichia coli and the Effect on Hypertrophic Scar Tissue

    PubMed Central

    Jia, Xuechao; Tian, Haishan; Tang, Lu; Zheng, Long; Zheng, Lulu; Yang, Ting; Yu, Bingjie; Wang, Zhitao; Lin, Peng; Li, Xiaokun; Wang, Xiaojie

    2015-01-01

    Background Basic fibroblast growth factor (bFGF) is a member of the fibroblast growth factor family that has effects on wounding healing and neuro-protection. However, it is difficult to use bFGF to treat diseases that are separated by physiological barriers, such as the dermal barrier and blood brain barrier. Methodology/Principal Findings To improve bFGF’s penetration ability, we fused the recombinant human fibroblast growth factor (rhbFGF) gene with TAT. We constructed a pET3c vector that contained the recombinant bFGF gene and successfully expressed this gene in the E. coli strain BL21 (DE3) pLsS. The fusion protein was purified using CM Sepharose FF and heparin affinity chromatography. The purity of the TAT-rhbFGF was greater than 95%, as detected by SDS-PAGE. An in vitro MTT trial revealed that the modified bFGF significantly promoted the proliferation of NIH3T3 cells. The cell penetration trial and the mouse skin penetration trial demonstrated that the fusion protein had certain penetration abilities. The animal experiments confirmed that TAT-rhbFGF was effective in the treatment of the hypertrophic scars. Conclusions/Significance We have successfully expressed and purified a TAT-rhbFGF fusion protein in this study. Our results have shown that the fusion protein had a greater ability to penetrate the dermal skin layer. TAT-rhbFGF improved the physical appearance of hypertrophic scars. TAT-rhbFGF may be a potential fusion protein in the treatment of dermal disorders, including hypertrophic scar. PMID:25706539

  6. Super-X divertors and high power density fusion devices

    SciTech Connect

    Valanju, P. M.; Kotschenreuther, M.; Mahajan, S. M.; Canik, J.

    2009-05-15

    The Super-X Divertor (SXD), a robust axisymmetric redesign of the divertor magnetic geometry that can allow a fivefold increase in the core power density of toroidal fusion devices, is presented. With small changes in poloidal coils and currents for standard divertors, the SXD allows the largest divertor plate radius inside toroidal field coils. This increases the plasma-wetted area by 2-3 times over all flux-expansion-only methods (e.g., plate near main X point, plate tilting, X divertor, and snowflake), decreases parallel heat flux and hence plasma temperature at plate, and increases connection length by 2-5 times. Examples of high-power-density fusion devices enabled by SXD are discussed; the most promising near-term device is a 100 MW modular compact fusion neutron source 'battery' small enough to fit inside a conventional fission blanket.

  7. Evaluation of Characteristics of High Efficiency Power Generation Systems Utilizing Fermentation Gas of Simply Sorted Municipal Refuse

    NASA Astrophysics Data System (ADS)

    Pak, Pyong Sik

    This paper evaluates characteristics of two kinds of power generation systems utilizing fermentation gas of municipal refuse which is generated with use of a fermentation equipment of sorted refuse from ordinary collected garbage. In evaluation, a garbage incineration plant treating refuse of 100 t/d was adopted. The two systems investigated are the following systems: (a) gas engine power generation system (Sys-GE) and (b) steam turbine power generation system with super heater of steam (Sys-SH). The characteristics of two systems have been estimated together with the conventional steam turbine power generation system (Sys-C). It has been estimated that Sys-GE and Sys-SH has 2.11 and 2.55 times greater energy saving and CO2 reduction effect compared with Sys-C, respectively.

  8. Simplified coupling power model for fibers fusion

    NASA Astrophysics Data System (ADS)

    Saktioto, J.; Ali, J.; Fadhali, M.

    2009-09-01

    Fiber coupler fabrication used for an optical waveguide requires lossless power for an optimal application. The previous research coupled fibers were successfully fabricated by injecting hydrogen flow at 1 bar and fused slightly by unstable torch flame in the range of 800-1350°C. Optical parameters may vary significantly over wide range physical properties. Coupling coefficient and refractive index are estimated from the experimental result of the coupling ratio distribution from 1% to 75%. The change of geometrical fiber affects the normalized frequency V even for single mode fibers. V is derived and some parametric variations are performed on the left and right hand side of the coupling region. A partial power is modelled and derived using V, normalized lateral phase constant u, and normalized lateral attenuation constant, w through the second kind of modified Bessel function of the l order, which obeys the normal mode and normalized propagation constant b. Total power is maintained constant in order to comply with the energy conservation law. The power is integrated through V, u, and w over the pulling length of 7500 µm for 1-D. The core radius of a fiber significantly affects V and power partially at coupling region rather than wavelength and refractive index of core and cladding. This model has power phenomena in transmission and reflection for an optical switch and tunable filter.

  9. Advanced Fusion Reactors for Space Propulsion and Power Systems

    NASA Technical Reports Server (NTRS)

    Chapman, John J.

    2011-01-01

    In recent years the methodology proposed for conversion of light elements into energy via fusion has made steady progress. Scientific studies and engineering efforts in advanced fusion systems designs have introduced some new concepts with unique aspects including consideration of Aneutronic fuels. The plant parameters for harnessing aneutronic fusion appear more exigent than those required for the conventional fusion fuel cycle. However aneutronic fusion propulsion plants for Space deployment will ultimately offer the possibility of enhanced performance from nuclear gain as compared to existing ionic engines as well as providing a clean solution to Planetary Protection considerations and requirements. Proton triggered 11Boron fuel (p- 11B) will produce abundant ion kinetic energy for In-Space vectored thrust. Thus energetic alpha particles "exhaust" momentum can be used directly to produce high ISP thrust and also offer possibility of power conversion into electricity. p- 11B is an advanced fusion plant fuel with well understood reaction kinematics but will require some new conceptual thinking as to the most effective implementation.

  10. Advanced Fusion Reactors for Space Propulsion and Power Systems

    SciTech Connect

    Chapman, John J.

    2011-06-15

    In recent years the methodology proposed for conversion of light elements into energy via fusion has made steady progress. Scientific studies and engineering efforts in advanced fusion systems designs have introduced some new concepts with unique aspects including consideration of Aneutronic fuels. The plant parameters for harnessing aneutronic fusion appear more exigent than those required for the conventional fusion fuel cycle. However aneutronic fusion propulsion plants for Space deployment will ultimately offer the possibility of enhanced performance from nuclear gain as compared to existing ionic engines as well as providing a clean solution to Planetary Protection considerations and requirements. Proton triggered 11Boron fuel (p- 11B) will produce abundant ion kinetic energy for In-Space vectored thrust. Thus energetic alpha particles' exhaust momentum can be used directly to produce high Isp thrust and also offer possibility of power conversion into electricity. p-11B is an advanced fusion plant fuel with well understood reaction kinematics but will require some new conceptual thinking as to the most effective implementation.

  11. Investigation of materials for fusion power reactors

    NASA Astrophysics Data System (ADS)

    Bouhaddane, A.; Slugeň, V.; Sojak, S.; Veterníková, J.; Petriska, M.; Bartošová, I.

    2014-06-01

    The possibility of application of nuclear-physical methods to observe radiation damage to structural materials of nuclear facilities is nowadays a very actual topic. The radiation damage to materials of advanced nuclear facilities, caused by extreme radiation stress, is a process, which significantly limits their operational life as well as their safety. In the centre of our interest is the study of the radiation degradation and activation of the metals and alloys for the new nuclear facilities (Generation IV fission reactors, fusion reactors ITER and DEMO). The observation of the microstructure changes in the reactor steels is based on experimental investigation using the method of positron annihilation spectroscopy (PAS). The experimental part of the work contains measurements focused on model reactor alloys and ODS steels. There were 12 model reactor steels and 3 ODS steels. We were investigating the influence of chemical composition on the production of defects in crystal lattice. With application of the LT 9 program, the spectra of specimen have been evaluated and the most convenient samples have been determined.

  12. 16 W output power by high-efficient spectral beam combining of DBR-tapered diode lasers.

    PubMed

    Müller, André; Vijayakumar, Deepak; Jensen, Ole Bjarlin; Hasler, Karl-Heinz; Sumpf, Bernd; Erbert, Götz; Andersen, Peter E; Petersen, Paul Michael

    2011-01-17

    Up to 16 W output power has been obtained using spectral beam combining of two 1063 nm DBR-tapered diode lasers. Using a reflecting volume Bragg grating, a combining efficiency as high as 93.7% is achieved, resulting in a single beam with high spatial coherence. The result represents the highest output power achieved by spectral beam combining of two single element tapered diode lasers. Since spectral beam combining does not affect beam propagation parameters, M2-values of 1.8 (fast axis) and 3.3 (slow axis) match the M2-values of the laser with lowest spatial coherence. The principle of spectral beam combining used in our experiments can be expanded to combine more than two tapered diode lasers and hence it is expected that the output power may be increased even further in the future.

  13. High efficiency, diode pumped Nd:YAG ceramics slab laser with 230 W continuous-wave output power.

    PubMed

    Lapucci, Antonio; Ciofini, Marco; Vannoni, Maurizo; Sordini, Andrea

    2012-06-20

    Diode pumped zig-zag slab lasers are widely adopted for continuous-wave high power or pulsed high energy applications. Recently [J. Eur. Opt. Soc.-Rapid 6, 11041 (2011)] we started to investigate a new thin slab format in which pumping radiation input is obtained through the thin lateral faces (edge pumping) and the beam propagation takes place bouncing on these same lateral faces ("edge zig-zag"). We report on the optimized operation of a ceramic Nd:YAG laser, based on this geometry, extracting 230 W at a 43% output power to diode power conversion efficiency. Thorough investigation of the thermal lens effect allows us to analyze the optical cavity and thus to define the main aspects limiting the present laser configuration.

  14. Manufacturing Methods and Technology Engineering High-Efficiency, High-Power Gallium Arsenide Read-Type IMPATT Diodes. Volume I.

    DTIC Science & Technology

    1977-08-01

    A design review of Read profile IMPATT diodes is presented. Work performed on this program to achieve the target specifications for high power X-band...applied to the manufacturing processes to improve the production rates of Read IMPATT diodes. This included spray dicing of the wafers, and new thermal

  15. Superstructure high efficiency photovoltaics

    NASA Technical Reports Server (NTRS)

    Wagner, M.; So, L. C.; Leburton, J. P.

    1987-01-01

    A novel class of photovoltaic cascade structures is introduced which features multijunction upper subcells. These superstructure high efficiency photovoltaics (SHEP's) exhibit enhanced upper subcell spectral response because of the additional junctions which serve to reduce bulk recombination losses by decreasing the mean collection distance for photogenerated minority carriers. Two possible electrical configurations were studied and compared: a three-terminal scheme that allows both subcells to be operated at their individual maximum power points and a two-terminal configuration with an intercell ohmic contact for series interconnection. The three-terminal devices were found to be superior both in terms of beginning-of-life expectancy and radiation tolerance. Realistic simulations of three-terminal AlGaAs/GaAs SHEP's show that one sun AMO efficiencies in excess of 26 percent are possible.

  16. Techno-Economic Feasibility of Highly Efficient Cost-Effective Thermoelectric-SOFC Hybrid Power Generation Systems

    SciTech Connect

    Jifeng Zhang; Jean Yamanis

    2007-09-30

    Solid oxide fuel cell (SOFC) systems have the potential to generate exhaust gas streams of high temperature, ranging from 400 to 800 C. These high temperature gas streams can be used for additional power generation with bottoming cycle technologies to achieve higher system power efficiency. One of the potential candidate bottoming cycles is power generation by means of thermoelectric (TE) devices, which have the inherent advantages of low noise, low maintenance and long life. This study was to analyze the feasibility of combining coal gas based SOFC and TE through system performance and cost techno-economic modeling in the context of multi-MW power plants, with 200 kW SOFC-TE module as building blocks. System and component concepts were generated for combining SOFC and TE covering electro-thermo-chemical system integration, power conditioning system (PCS) and component designs. SOFC cost and performance models previously developed at United Technologies Research Center were modified and used in overall system analysis. The TE model was validated and provided by BSST. The optimum system in terms of energy conversion efficiency was found to be a pressurized SOFC-TE, with system efficiency of 65.3% and cost of $390/kW of manufacturing cost. The pressurization ratio was approximately 4 and the assumed ZT of the TE was 2.5. System and component specifications were generated based on the modeling study. The major technology and cost barriers for maturing the system include pressurized SOFC stack using coal gas, the high temperature recycle blowers, and system control design. Finally, a 4-step development roadmap is proposed for future technology development, the first step being a 1 kW proof-of-concept demonstration unit.

  17. Assessment of tritium breeding requirements for fusion power reactors

    SciTech Connect

    Jung, J.

    1983-12-01

    This report presents an assessment of tritium-breeding requirements for fusion power reactors. The analysis is based on an evaluation of time-dependent tritium inventories in the reactor system. The method presented can be applied to any fusion systems in operation on a steady-state mode as well as on a pulsed mode. As an example, the UWMAK-I design was analyzed and it has been found that the startup inventory requirement calculated by the present method significantly differs from those previously calculated. The effect of reactor-parameter changes on the required tritium breeding ratio is also analyzed for a variety of reactor operation scenarios.

  18. A fusion power plant without plasma-material interactions

    SciTech Connect

    Cohen, S.A.

    1997-04-01

    A steady-state fusion power plant is described which avoids the deleterious plasma-material interactions found in D-T fueled tokamaks. It is based on driven p-{sup 11}B fusion in a high-beta closed-field device, the field-reversed configuration (FRC), anchored in a gas-dynamic trap (GDT). The plasma outflow on the open magnetic-field lines is cooled by radiation in the GDT, then channeled through a magnetic nozzle, promoting 3-body recombination in the expansion region. The resulting supersonic neutral exhaust stream flows through a turbine, generating electricity.

  19. Improved power capacity in a high efficiency klystron-like relativistic backward wave oscillator by distributed energy extraction

    NASA Astrophysics Data System (ADS)

    Xiao, Renzhen; Chen, Changhua; Cao, Yibing; Sun, Jun

    2013-12-01

    With the efficiency increase of a klystron-like relativistic backward wave oscillator, the maximum axial electric field and harmonic current simultaneously appear at the end of the beam-wave interaction region, leading to a highly centralized energy exchange in the dual-cavity extractor and a very high electric field on the cavity surface. Thus, we present a method of distributed energy extraction in this kind of devices. Particle-in-cell simulations show that with the microwave power of 5.1 GW and efficiency of 70%, the maximum axial electric field is decreased from 2.26 MV/cm to 1.28 MV/cm, indicating a threefold increase in the power capacity.

  20. Improved power capacity in a high efficiency klystron-like relativistic backward wave oscillator by distributed energy extraction

    SciTech Connect

    Xiao, Renzhen; Chen, Changhua; Cao, Yibing; Sun, Jun

    2013-12-07

    With the efficiency increase of a klystron-like relativistic backward wave oscillator, the maximum axial electric field and harmonic current simultaneously appear at the end of the beam-wave interaction region, leading to a highly centralized energy exchange in the dual-cavity extractor and a very high electric field on the cavity surface. Thus, we present a method of distributed energy extraction in this kind of devices. Particle-in-cell simulations show that with the microwave power of 5.1 GW and efficiency of 70%, the maximum axial electric field is decreased from 2.26 MV/cm to 1.28 MV/cm, indicating a threefold increase in the power capacity.

  1. Vertical Stand Transparent Light-Emitting Diode Architecture for High-Efficiency and High-Power Light-Emitting Diodes

    NASA Astrophysics Data System (ADS)

    Pan, Chih-Chien; Koslow, Ingrid; Sonoda, Junichi; Ohta, Hiroaki; Ha, Jun-Seok; Nakamura, Shuji; DenBaars, Steven P.

    2010-08-01

    Using a transparent ZnO vertical stand as a submount, a novel Light-emitting diode architecture, which is similar to conventional lighting bulbs, was proposed. The emission power of a blue LED based on c-plane (0001) bulk GaN was increased by 14.2 and 5.1% compared with those of conventional and suspended die packages, respectively. The output power and external quantum efficiency of LEDs respectively reached 31.7 mW and 57.1% at a forward current of 20 mA under direct current conditions. The high thermal conductivity and refractive index of the transparent submount simultaneously resulted in high current operation and high external efficiency.

  2. High-efficiency space-based software radio architectures & algorithms (a minimum size, weight, and power TeraOps processor)

    SciTech Connect

    Dunham, Mark Edward; Baker, Zachary K; Stettler, Matthew W; Pigue, Michael J; Schmierer, Eric N; Power, John F; Graham, Paul S

    2009-01-01

    Los Alamos has recently completed the latest in a series of Reconfigurable Software Radios, which incorporates several key innovations in both hardware design and algorithms. Due to our focus on satellite applications, each design must extract the best size, weight, and power performance possible from the ensemble of Commodity Off-the-Shelf (COTS) parts available at the time of design. In this case we have achieved 1 TeraOps/second signal processing on a 1920 Megabit/second datastream, while using only 53 Watts mains power, 5.5 kg, and 3 liters. This processing capability enables very advanced algorithms such as our wideband RF compression scheme to operate remotely, allowing network bandwidth constrained applications to deliver previously unattainable performance.

  3. Modular stellarator reactor: a fusion power plant

    SciTech Connect

    Miller, R.L.; Bathke, C.G.; Krakowski, R.A.; Heck, F.M.; Green, L.; Karbowski, J.S.; Murphy, J.H.; Tupper, R.B.; DeLuca, R.A.; Moazed, A.

    1983-07-01

    A comparative analysis of the modular stellarator and the torsatron concepts is made based upon a steady-state ignited, DT-fueled, reactor embodiment of each concept for use as a central electric-power station. Parametric tradeoff calculations lead to the selection of four design points for an approx. 4-GWt plant based upon Alcator transport scaling in l = 2 systems of moderate aspect ratio. The four design points represent high-aspect ratio. The four design points represent high-(0.08) and low-(0.04) beta versions of the modular stellarator and torsatron concepts. The physics basis of each design point is described together with supporting engineering and economic analyses. The primary intent of this study is the elucidation of key physics and engineering tradeoffs, constraints, and uncertainties with respect to the ultimate power reactor embodiment.

  4. Fusion powered human transport to Mars (UWFR94)

    NASA Technical Reports Server (NTRS)

    Cappellari, John; Grota, Susan; Hagedorn, David; Hirai, Yoshi; Remmel, Mark; Schmidt, Deanna; Sveum, Matt; Wandow, Helena

    1994-01-01

    In the future, two important technological dreams will have become reality: fusion will be a viable power source, and human settlement on Mars will be feasible, desirable, and even necessary. Merging these two concepts is especially attractive for the aerospace engineer because of the high specific power that will be possible with fusion (on the order 10 kW/kg). The UWFR94, a large, fusion-powered, human-transport ship, is designed to transport 100 passengers between earth and Mars in approximately thirty days. This relatively short transit time, which mitigates the need for artificial gravity, is made possible by a Polywell inertial electrostatic fusion reactor capable of 20 kW/kg. The mass of each reactor is 37 metric tons and the fuel used is (3)He-(3)He. The electricity generated drives the propulsion system, composed of nine ion thrusters and 780 tons of xenon propellant. The payload consists of three independent, identical cylinders housing the crew, and has a mass of approximately 400 tons. The aluminum cylinders' radius and length are 3 and 12 meters, respectively, with a thickness of 6 cm (15 cm in the solar flare safe rooms). Atmospheric reentry is avoided by constructing and repairing the UWFR94 in space, and by transferring crew and cargo to shuttle-like vehicles for transportation to the planet upon arrival.

  5. Fusion primer and nested integrated PCR (FPNI-PCR): a new high-efficiency strategy for rapid chromosome walking or flanking sequence cloning

    PubMed Central

    2011-01-01

    Background The advent of genomics-based technologies has revolutionized many fields of biological enquiry. However, chromosome walking or flanking sequence cloning is still a necessary and important procedure to determining gene structure. Such methods are used to identify T-DNA insertion sites and so are especially relevant for organisms where large T-DNA insertion libraries have been created, such as rice and Arabidopsis. The currently available methods for flanking sequence cloning, including the popular TAIL-PCR technique, are relatively laborious and slow. Results Here, we report a simple and effective fusion primer and nested integrated PCR method (FPNI-PCR) for the identification and cloning of unknown genomic regions flanked known sequences. In brief, a set of universal primers was designed that consisted of various 15-16 base arbitrary degenerate oligonucleotides. These arbitrary degenerate primers were fused to the 3' end of an adaptor oligonucleotide which provided a known sequence without degenerate nucleotides, thereby forming the fusion primers (FPs). These fusion primers are employed in the first step of an integrated nested PCR strategy which defines the overall FPNI-PCR protocol. In order to demonstrate the efficacy of this novel strategy, we have successfully used it to isolate multiple genomic sequences namely, 21 orthologs of genes in various species of Rosaceace, 4 MYB genes of Rosa rugosa, 3 promoters of transcription factors of Petunia hybrida, and 4 flanking sequences of T-DNA insertion sites in transgenic tobacco lines and 6 specific genes from sequenced genome of rice and Arabidopsis. Conclusions The successful amplification of target products through FPNI-PCR verified that this novel strategy is an effective, low cost and simple procedure. Furthermore, FPNI-PCR represents a more sensitive, rapid and accurate technique than the established TAIL-PCR and hiTAIL-PCR procedures. PMID:22093809

  6. Nanofluidic crystal: a facile, high-efficiency and high-power-density scaling up scheme for energy harvesting based on nanofluidic reverse electrodialysis.

    PubMed

    Ouyang, Wei; Wang, Wei; Zhang, Haixia; Wu, Wengang; Li, Zhihong

    2013-08-30

    The great advances in nanotechnology call for advances in miniaturized power sources for micro/nano-scale systems. Nanofluidic channels have received great attention as promising high-power-density substitutes for ion exchange membranes for use in energy harvesting from ambient ionic concentration gradient, namely reverse electrodialysis. This paper proposes the nanofluidic crystal (NFC), of packed nanoparticles in micro-meter-sized confined space, as a facile, high-efficiency and high-power-density scaling-up scheme for energy harvesting by nanofluidic reverse electrodialysis (NRED). Obtained from the self-assembly of nanoparticles in a micropore, the NFC forms an ion-selective network with enormous nanochannels due to electrical double-layer overlap in the nanoparticle interstices. As a proof-of-concept demonstration, a maximum efficiency of 42.3 ± 1.84%, a maximum power density of 2.82 ± 0.22 W m(-2), and a maximum output power of 1.17 ± 0.09 nW/unit (nearly three orders of magnitude of amplification compared to other NREDs) were achieved in our prototype cell, which was prepared within 30 min. The current NFC-based prototype cell can be parallelized and cascaded to achieve the desired output power and open circuit voltage. This NFC-based scaling-up scheme for energy harvesting based on NRED is promising for the building of self-powered micro/nano-scale systems.

  7. IEC fusion: The future power and propulsion system for space

    NASA Astrophysics Data System (ADS)

    Hammond, Walter E.; Coventry, Matt; Hanson, John; Hrbud, Ivana; Miley, George H.; Nadler, Jon

    2000-01-01

    Rapid access to any point in the solar system requires advanced propulsion concepts that will provide extremely high specific impulse, low specific power, and a high thrust-to-power ratio. Inertial Electrostatic Confinement (IEC) fusion is one of many exciting concepts emerging through propulsion and power research in laboratories across the nation which will determine the future direction of space exploration. This is part of a series of papers that discuss different applications of the Inertial Electrostatic Confinement (IEC) fusion concept for both in-space and terrestrial use. IEC will enable tremendous advances in faster travel times within the solar system. The technology is currently under investigation for proof of concept and transitioning into the first prototype units for commercial applications. In addition to use in propulsion for space applications, terrestrial applications include desalinization plants, high energy neutron sources for radioisotope generation, high flux sources for medical applications, proton sources for specialized medical applications, and tritium production. .

  8. Materials integration issues for high performance fusion power systems.

    SciTech Connect

    Smith, D. L.

    1998-01-14

    One of the primary requirements for the development of fusion as an energy source is the qualification of materials for the frost wall/blanket system that will provide high performance and exhibit favorable safety and environmental features. Both economic competitiveness and the environmental attractiveness of fusion will be strongly influenced by the materials constraints. A key aspect is the development of a compatible combination of materials for the various functions of structure, tritium breeding, coolant, neutron multiplication and other special requirements for a specific system. This paper presents an overview of key materials integration issues for high performance fusion power systems. Issues such as: chemical compatibility of structure and coolant, hydrogen/tritium interactions with the plasma facing/structure/breeder materials, thermomechanical constraints associated with coolant/structure, thermal-hydraulic requirements, and safety/environmental considerations from a systems viewpoint are presented. The major materials interactions for leading blanket concepts are discussed.

  9. ARC: A compact, high-field, disassemblable fusion nuclear science facility and demonstration power plant

    NASA Astrophysics Data System (ADS)

    Sorbom, Brandon; Ball, Justin; Palmer, Timothy; Mangiarotti, Franco; Sierchio, Jennifer; Bonoli, Paul; Kasten, Cale; Sutherland, Derek; Barnard, Harold; Haakonsen, Christian; Goh, Jon; Sung, Choongki; Whyte, Dennis

    2014-10-01

    The Affordable, Robust, Compact (ARC) reactor conceptual design aims to reduce the size, cost, and complexity of a combined Fusion Nuclear Science Facility (FNSF) and demonstration fusion pilot power plant. ARC is a 270 MWe tokamak reactor with a major radius of 3.3 m, a minor radius of 1.1 m, and an on-axis magnetic field of 9.2 T. ARC has Rare Earth Barium Copper Oxide (REBCO) superconducting toroidal field coils with joints to allow disassembly, allowing for removal and replacement of the vacuum vessel as a single component. Inboard-launched current drive of 25 MW LHRF power and 13.6 MW ICRF power is used to provide a robust, steady state core plasma far from disruptive limits. ARC uses an all-liquid blanket, consisting of low pressure, slowly flowing Fluorine Lithium Beryllium (FLiBe) molten salt. The liquid blanket acts as a working fluid, coolant, and tritium breeder, and minimizes the solid material that can become activated. The large temperature range over which FLiBe is liquid permits blanket operation at 800-900 K with single phase fluid cooling and allows use of a high-efficiency Brayton cycle for electricity production in the secondary coolant loop.

  10. Laser driven nuclear science and applications: The need of high efficiency, high power and high repetition rate Laser beams

    NASA Astrophysics Data System (ADS)

    Gales, S.

    2015-10-01

    Extreme Light Infrastructure (ELI) is a pan European research initiative selected on the European Strategy Forum on Research Infrastructures Roadmap that aims to close the gap between the existing laboratory-based laser driven research and international facility-grade research centre. The ELI-NP facility, one of the three ELI pillars under construction, placed in Romania and to be operational in 2018, has as core elements a couple of new generation 10 PW laser systems and a narrow bandwidth Compton backscattering gamma source with photon energies up to 19 MeV. ELI-NP will address nuclear photonics, nuclear astrophysics and quantum electrodynamics involving extreme photon fields. Prospective applications of high power laser in nuclear astrophysics, accelerator physics, in particular towards future Accelerator Driven System, as well as in nuclear photonics, for detection and characterization of nuclear material, and for nuclear medicine, will be discussed. Key issues in these research areas will be at reach with significant increase of the repetition rates and of the efficiency at the plug of the high power laser systems as proposed by the ICAN collaboration.

  11. Very High Efficiency, Miniaturized, Long-Lived Alpha Particle Power Source Using Diamond Devices for Extreme Space Environments

    NASA Technical Reports Server (NTRS)

    Kolawa, Elizabeth A. (Inventor); Patel, Jagdishbhai U. (Inventor); Fleurial, Jean-Pierre (Inventor)

    2004-01-01

    A power source that converts a-particle energy into electricity by coulomb collision in doped diamond films is described. Alpha particle decay from curium-244 creates electron-hole pairs by free- ing electrons and holes inside the crystal lattice in N- and P-doped diamond films. Ohmic contacts provide electrical connection to an electronic device. Due to the built-in electric field at the rectifying junction across the hT- and P-doped diamond films, the free electrons are constrained to traveling in generally one direction. This one direction then supplies electrons in a manner similar to that of a battery. The radioactive curium layer may be disposed on diamond films for even distribution of a-particle radiation. The resulting power source may be mounted on a diamond substrate that serves to insulate structures below the diamond substrate from a-particle emission. Additional insulation or isolation may be provided in order to prevent damage from a-particle collision. N-doped silicon may be used instead of N-doped diamond.

  12. Personnel Safety for Future Magnetic Fusion Power Plants

    SciTech Connect

    Lee Cadwallader

    2009-07-01

    The safety of personnel at existing fusion experiments is an important concern that requires diligence. Looking to the future, fusion experiments will continue to increase in power and operating time until steady state power plants are achieved; this causes increased concern for personnel safety. This paper addresses four important aspects of personnel safety in the present and extrapolates these aspects to future power plants. The four aspects are personnel exposure to ionizing radiation, chemicals, magnetic fields, and radiofrequency (RF) energy. Ionizing radiation safety is treated well for present and near-term experiments by the use of proven techniques from other nuclear endeavors. There is documentation that suggests decreasing the annual ionizing radiation exposure limits that have remained constant for several decades. Many chemicals are used in fusion research, for parts cleaning, as use as coolants, cooling water cleanliness control, lubrication, and other needs. In present fusion experiments, a typical chemical laboratory safety program, such as those instituted in most industrialized countries, is effective in protecting personnel from chemical exposures. As fusion facilities grow in complexity, the chemical safety program must transition from a laboratory scale to an industrial scale program that addresses chemical use in larger quantity. It is also noted that allowable chemical exposure concentrations for workers have decreased over time and, in some cases, now pose more stringent exposure limits than those for ionizing radiation. Allowable chemical exposure concentrations have been the fastest changing occupational exposure values in the last thirty years. The trend of more restrictive chemical exposure regulations is expected to continue into the future. Other issues of safety importance are magnetic field exposure and RF energy exposure. Magnetic field exposure limits are consensus values adopted as best practices for worker safety; a typical

  13. High efficiency and high peak power picosecond mid-infrared optical parametric amplifier based on BaGa4Se7 crystal.

    PubMed

    Yang, Feng; Yao, Ji-yong; Xu, Hong-yan; Feng, Kai; Yin, Wen-long; Li, Fang-qin; Yang, Jing; Du, Shi-feng; Peng, Qin-jun; Zhang, Jing-yuan; Cui, Da-fu; Wu, Yi-cheng; Chen, Chuang-tian; Xu, Zu-yan

    2013-10-01

    A high efficiency and high peak power picosecond (ps) mid-infrared optical parametric amplifier with a new nonlinear crystal BaGa(4)Se(7) pumped by a 30 ps 1064 nm Nd:YAG laser is demonstrated for the first time. The maximum photon conversion efficiency of 56% from 1064 nm to 3.9 μm idler has been achieved at the pump energy of ~1.8 mJ. A maximum idler output of 830 μJ at 3.9 μm with peak power of ~27 MW was obtained at pump energy of ~9.1 mJ. Moreover, a 3-5 μm idler tuning range was demonstrated, with output energies of ~300 μJ at 5 μm and up to 1 mJ at 3 μm at ~8.2 mJ pump energy.

  14. LIFE: a sustainable solution for developing safe, clean fusion power.

    PubMed

    Reyes, Susana; Dunne, Mike; Kramer, Kevin; Anklam, Tom; Havstad, Mark; Mazuecos, Antonio Lafuente; Miles, Robin; Martinez-Frias, Joel; Deri, Bob

    2013-06-01

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in California is currently in operation with the goal to demonstrate fusion energy gain for the first time in the laboratory-also referred to as "ignition." Based on these demonstration experiments, the Laser Inertial Fusion Energy (LIFE) power plant is being designed at LLNL in partnership with other institutions with the goal to deliver baseload electricity from safe, secure, sustainable fusion power in a time scale that is consistent with the energy market needs. For this purpose, the LIFE design takes advantage of recent advances in diode-pumped, solid-state laser technology and adopts the paradigm of Line Replaceable Units used on the NIF to provide high levels of availability and maintainability and mitigate the need for advanced materials development. The LIFE market entry plant will demonstrate the feasibility of a closed fusion fuel cycle, including tritium breeding, extraction, processing, refueling, accountability, and safety, in a steady-state power-producing device. While many fusion plant designs require large quantities of tritium for startup and operations, a range of design choices made for the LIFE fuel cycle act to reduce the in-process tritium inventory. This paper presents an overview of the delivery plan and the preconceptual design of the LIFE facility with emphasis on the key safety design principles being adopted. In order to illustrate the favorable safety characteristics of the LIFE design, some initial accident analysis results are presented that indicate potential for a more attractive licensing regime than that of current fission reactors.

  15. Thick liquid protection in inertial fusion power plants

    NASA Astrophysics Data System (ADS)

    Pemberton, Steven James

    Liquid jets are designed and developed for the construction of a thick-liquid first wall in fusion power plants, with attention to preventing line-of-sight interaction between target debris and solid structural materials in inertial fusion power plants. First, an introduction is given to basic fusion concepts in order to set the background for inertial fusion plant design. After this introduction, scaling relationships for experimental studies are presented and different jet types for thick-liquid inertial fusion chambers are described, including stationary cylindrical jet grids, large oscillating liquid slabs, and vortex tubes created from centrifugal flow inside pipes. The design of vortex tubes is given in some detail with an illustration of some simple concepts from fluid mechanics for the evolution of flow in the tubes, and the results of this basic analysis are compared to empirical results from a prototype device. The actual thickness of the vortex layer is found to depart from the ideal, laminar consideration of the flow development. However, the basic considerations also predict that flow in the vortex layer will remain stable in the region of interest, and will be independent of the volumetric flow rate. These estimates are supported by experimental observations. The construction of a prototype slab jet is also described, and one chapter of this dissertation is dedicated to the analysis of impulse delivery to and dispersion within a slab jet with finely dispersed voids. The reaction of a slab jet to impulse loading is predicted using a simple compressible flow model for incompressible fluid with dispersed voids. The model is compared with experimental impulse-load data, and it is found that this simple model does a fair job of predicting the empirical results. The dissertation concludes with a discussion of some important factors in vortex flow and slab jet disruption, and possible sources of departure from the basic analyses.

  16. High efficiency preparation of bioactive human alpha-defensin 6 in Escherichia coli Origami(DE3)pLysS by soluble fusion expression.

    PubMed

    Wang, Aiping; Su, Yongping; Wang, Song; Shen, Mingqiang; Chen, Fang; Chen, Mo; Ran, Xinze; Cheng, Tianmin; Wang, Junping

    2010-08-01

    Human alpha-defensin 6 (HD(6)), a small cysteine-rich cationic peptide specially expressed in epithelial cells of digestive tract, may play a crucial role in mucosal immunity. This is the first report on efficient production of bioactive HD(6) through a gene-engineering approach in Escherichia coli. The recombinant plasmid pET32a-omHD(6) was primarily constructed by inserting a PCR fragment encoding mature HD(6) peptide (mHD(6)) preceded by an enterokinase recognition sequence into the expression vector pET32a(+), in frame with the upstream thioredoxin (TrxA) gene. Under optimized expression conditions, a high percentage (>60%) of soluble TrxA-omHD(6) fusion protein was obtained with a yield of about 1.69 g/l, and the theoretical productivity of recombinant mHD(6) (rmHD(6)) reached 0.38 g/l. A feasible three-step purification strategy involving nickel-sepharose chromatography, enterokinase-cleavage and cation exchange chromatography was developed to purify rmHD(6), followed by characteristic identifications by Western blot, mass spectrometry and sequencing. About 102 mg/l of rmHD(6) with its intact N-terminal amino acid sequence was finally achieved. The in vitro experiments showed that rmHD(6) possesses high potency to inhibit herpes simplex virus-2 infection. This work settles substantial foundation for further functional study of HD(6).

  17. Pinch me - I'm fusing! Fusion Power - what is it? What is a z pinch? And why are z-pinches a promising fusion power technology?

    SciTech Connect

    DERZON,MARK S.

    2000-03-01

    The process of combining nuclei (the protons and neutrons inside an atomic nucleus) together with a release of kinetic energy is called fusion. This process powers the Sun, it contributes to the world stockpile of weapons of mass destruction and may one day generate safe, clean electrical power. Understanding the intricacies of fusion power, promised for 50 years, is sometimes difficult because there are a number of ways of doing it. There is hot fusion, cold fusion and con-fusion. Hot fusion is what powers suns through the conversion of mass energy to kinetic energy. Cold fusion generates con-fusion and nobody really knows what it is. Even so, no one is generating electrical power for you and me with either method. In this article the author points out some basic features of the mainstream approaches taken to hot fusion power, as well as describe why z pinches are worth pursuing as a driver for a power reactor and how it may one day generate electrical power for mankind.

  18. High-Efficiency Robust Free-Standing Composited Phosphor Films with 2D and 3D Nanostructures for High-Power Remote White LEDs.

    PubMed

    Lai, Chun-Feng; Li, Jia-Sian; Shen, Chung-Wen

    2017-02-08

    This study demonstrated that combined free-standing quasi-amorphous/micropattern (QA/MP) composited resin film-assisted phosphor films enhanced the mechanical robustness, luminous efficacy, color rendering index (CRI), and special R9 of high-power remote warm white light-emitting diodes (WLEDs). Introducing QA/MP nanostructures into phosphor film resulted in high efficiency of remote warm WLEDs with low phosphor thickness (approximately 25 μm) and reduced the correlated color temperature (CCT) from cold white light (approximately 5565 K) to warm white light (approximately 3178 K). The QA/MP composited phosphor films (CPFs) used for high-power remote WLEDs enhanced the CRI and special R9 and reduced the CCT. These results were attributed to that QA resin film reflected the blue light and re-emitted the added red emission. CIR (84), a natural warm white CCT (3178 K), and an acceptable luminous efficacy (102.5 lm/W) were achieved from the QA/MP CPFs of high-power remote WLEDs during operation at an input power of 10 W (current of 700 mA). The bending strength of QA/MP CPFs at approximately 112 N was significantly enhanced by 40% compared with that of flat CPFs. The QA/MP CPFs applied to high-power remote WLEDs exhibited good thermal and optical stability. QA/MP CPFs were also conducted to a reliability analysis (RA), in which temperature of 85 °C and relative humidity of 85% were applied for 3288 h. Lumen maintenance was degraded by 8% during RA test because the transmittance of trimethylolopropane ethoxylate triacrylate resins was degraded under high temperature. Overall, we implemented a reliable and inexpensive technology that can potentially reduce phosphor thickness, address the out-bin problems of defective WLEDs, and fabricate flat-panel lighting source with good lighting quality.

  19. Task toward a Realization of Commercial Tokamak Fusion Plants in 2050 -The Role of ITER and the Succeeding Developments- 3.Fusion Plasma Research toward Fusion Power Plants

    NASA Astrophysics Data System (ADS)

    Kamada, Yutaka; Shimada, Michiya; Miura, Yukitoshi; Ogawa, Yuichi

    This section discusses fusion plasma research that needs to be carried out to develop fusion power plants. Burning plasma, in which self-heating by energetic alph aparticles plays an essential role, should be recognized as autonomous system. This is quite different from present plasma experiments, suggesting a possibility to yield some qualitative changes in fusion plasma research. Research with ITER is strongly expected to contribute to this burning plasma physics. In addition, plasma performance in steady-state and at high beta is very important in fusion power plants from the engineering and economical viewpoints. Plasma parameters expected for fusion power plants are discussed, and present status of experimental research is reviewed. Research in devices other than ITER with unique features would be instrumental for exploring high performance plasmas. A necessity of research complementary to ITER plasma is discussed.

  20. High Efficiency, Clean Combustion

    SciTech Connect

    Donald Stanton

    2010-03-31

    Energy use in trucks has been increasing at a faster rate than that of automobiles within the U.S. transportation sector. According to the Energy Information Administration (EIA) Annual Energy Outlook (AEO), a 23% increase in fuel consumption for the U.S. heavy duty truck segment is expected between 2009 to 2020. The heavy duty vehicle oil consumption is projected to grow between 2009 and 2050 while light duty vehicle (LDV) fuel consumption will eventually experience a decrease. By 2050, the oil consumption rate by LDVs is anticipated to decrease below 2009 levels due to CAFE standards and biofuel use. In contrast, the heavy duty oil consumption rate is anticipated to double. The increasing trend in oil consumption for heavy trucks is linked to the vitality, security, and growth of the U.S. economy. An essential part of a stable and vibrant U.S. economy is a productive U.S. trucking industry. Studies have shown that the U.S. gross domestic product (GDP) is strongly correlated to freight transport. Over 90% of all U.S. freight tonnage is transported by diesel power and over 75% is transported by trucks. Given the vital role that the trucking industry plays in the economy, improving the efficiency of the transportation of goods was a central focus of the Cummins High Efficient Clean Combustion (HECC) program. In a commercial vehicle, the diesel engine remains the largest source of fuel efficiency loss, but remains the greatest opportunity for fuel efficiency improvements. In addition to reducing oil consumption and the dependency on foreign oil, this project will mitigate the impact on the environment by meeting US EPA 2010 emissions regulations. Innovation is a key element in sustaining a U.S. trucking industry that is competitive in global markets. Unlike passenger vehicles, the trucking industry cannot simply downsize the vehicle and still transport the freight with improved efficiency. The truck manufacturing and supporting industries are faced with numerous

  1. HIGH EFFICIENCY SYNGAS GENERATION

    SciTech Connect

    Robert J. Copeland; Yevgenia Gershanovich; Brian Windecker

    2005-02-01

    This project investigated an efficient and low cost method of auto-thermally reforming natural gas to hydrogen and carbon monoxide. Reforming is the highest cost step in producing products such as methanol and Fisher Tropsch liquids (i.e., gas to liquids); and reducing the cost of reforming is the key to reducing the cost of these products. Steam reforming is expensive because of the high cost of the high nickel alloy reforming tubes (i.e., indirectly fired reforming tubes). Conventional auto-thermal or Partial Oxidation (POX) reforming minimizes the size and cost of the reformers and provides a near optimum mixture of CO and hydrogen. However POX requires pure oxygen, which consumes power and significantly increases the cost to reforming. Our high efficiency process extracts oxygen from low-pressure air with novel oxygen sorbent and transfers the oxygen to a nickel-catalyzed reformer. The syngas is generated at process pressure (typically 20 to 40 bar) without nitrogen dilution and has a 1CO to 2H{sub 2} ratio that is near optimum for the subsequent production of Fisher-Tropsch liquid to liquids and other chemicals (i.e., Gas to Liquids, GTL). Our high process efficiency comes from the way we transfer the oxygen into the reformer. All of the components of the process, except for the oxygen sorbent, are commonly used in commercial practice. A process based on a longlived, regenerable, oxygen transfer sorbent could substantially reduce the cost of natural gas reforming to syngas. Lower cost syngas (CO + 2H{sub 2}) that is the feedstock for GTL would reduce the cost of GTL and for other commercial applications (e.g., methanol, other organic chemicals). The vast gas resources of Alaska's North Slope (ANS) offer more than 22 Tcf of gas and GTL production in this application alone, and could account for as much as 300,000 to 700,000 bpd for 20 to 30+ years. We developed a new sorbent, which is an essential part of the High Efficiency Oxygen Process (HOP). We tested the

  2. Physics assessment of stellarators as fusion power plants

    SciTech Connect

    Lyon, J.F.; Rome, J.A.; Garabedian, P.R.; Anderson, D.T.; Painter, S.L.

    1995-02-01

    Four different stellarator configurations (a Compact Torsatron, a new modular torsatron, Helias, and a new Modular Helias-like Heliac) were analyzed as fusion power plants and compared with the second-stability ARIES-IV tokamak. The device and plasma parameters were determined by minimizing the projected cost of electricity subject to various constraints. The stellarators were competitive with ARIES-IV for a range of assumptions on confinement models, alpha-particle losses, and beta. 1-D power balance equations were solved for both Lackner-Gottardi confinement scaling with an assumed n{sub e}(r) and for helical-ripple-induced transport with both assumed and calculated forms for n{sub e}(r) and E{sub r}(r).

  3. Design considerations for an inertial confinement fusion reactor power plant

    SciTech Connect

    Massey, J.V.; Simpson, J.E.

    1981-08-10

    To further define the engineering and economic concerns for inertial confinement fusion reactors (ICR's), a conceptual design study was performed by Bechtel Group Incorporated under the direction of Lawrence Livermore National Laboratory (LLNL). The study examined alternatives to the LLNL HYLIFE concept and expanded the previous balance of plant design to incorporate information from recent liquid metal cooled fast breeder reactor (LMFBR) power plant studies. The majority of the effort was to incorporate present laser and target physics models into a reactor design with a low coolant flowrate and a high driver repetition rate. An example of such a design is the LLNL JADE concept. In addition to producing a power plant design for LLNL using the JADE example, Bechtel has also examined the applicability of the EAGLE (Energy Absorbing Gas Lithium Ejector) concept.

  4. Fabrication of Very High Efficiency 5.8 GHz Power Amplifiers using AlGaN HFETs on SiC Substrates for Wireless Power Transmission

    NASA Technical Reports Server (NTRS)

    Sullivan, Gerry

    2001-01-01

    For wireless power transmission using microwave energy, very efficient conversion of the DC power into microwave power is extremely important. Class E amplifiers have the attractive feature that they can, in theory, be 100% efficient at converting, DC power to RF power. Aluminum gallium nitride (AlGaN) semiconductor material has many advantageous properties, relative to silicon (Si), gallium arsenide (GaAs), and silicon carbide (SiC), such as a much larger bandgap, and the ability to form AlGaN/GaN heterojunctions. The large bandgap of AlGaN also allows for device operation at higher temperatures than could be tolerated by a smaller bandgap transistor. This could reduce the cooling requirements. While it is unlikely that the AlGaN transistors in a 5.8 GHz class E amplifier can operate efficiently at temperatures in excess of 300 or 400 C, AlGaN based amplifiers could operate at temperatures that are higher than a GaAs or Si based amplifier could tolerate. Under this program, AlGaN microwave power HFETs have been fabricated and characterized. Hybrid class E amplifiers were designed and modeled. Unfortunately, within the time frame of this program, good quality HFETs were not available from either the RSC laboratories or commercially, and so the class E amplifiers were not constructed.

  5. A dual-mode highly efficient class-E stimulator controlled by a low-Q class-E power amplifier through duty cycle.

    PubMed

    Chiu, Hung-Wei; Lu, Chien-Chi; Chuang, Jia-min; Lin, Wei-Tso; Lin, Chii-Wann; Kao, Ming-Chien; Lin, Mu-Lien

    2013-06-01

    This paper presents the design flow of two high-efficiency class-E amplifiers for the implantable electrical stimulation system. The implantable stimulator is a high-Q class-E driver that delivers a sine-wave pulsed radiofrequency (PRF) stimulation, which was verified to have a superior efficacy in pain relief to a square wave. The proposed duty-cycle-controlled class-E PRF driver designed with a high-Q factor has two operational modes that are able to achieve 100% DC-AC conversion, and involves only one switched series inductor and an unchanged parallel capacitor. The measured output amplitude under low-voltage (LV) mode using a 22% duty cycle was 0.98 V with 91% efficiency, and under high-voltage (HV) mode using a 47% duty cycle was 2.95 V with 92% efficiency. These modes were inductively controlled by a duty-cycle detector, which can detect the duty-cycle modulated signal generated from the external complementary low-Q class-E power amplifier (PA). The design methodology of the low-Q inductive interface for a non-50% duty cycle is presented. The experimental results exhibits that the 1.5-V PA that consumes DC power of 14.21 mW was able to deliver a 2.9-V sine wave to a 500 Ω load. The optimal 60% drain efficiency of the system from the PA to the load was obtained at a 10-mm coupling distance.

  6. Homogeneous deposition-assisted synthesis of iron-nitrogen composites on graphene as highly efficient non-precious metal electrocatalysts for microbial fuel cell power generation

    NASA Astrophysics Data System (ADS)

    Liu, Yuan; Jin, Xiao-Jun; Dionysiou, Dionysios D.; Liu, Hong; Huang, Yu-Ming

    2015-03-01

    This work proposed a novel strategy for synthesizing highly efficient non-precious metal oxygen reduction reaction (ORR) electrocatalysts. Fe complexes were homogeneously deposited (HD) on graphene oxide through in situ hydrolysis of urea, followed by two-step pyrolysis under Ar and NH3 atmospheres, resulting in formation of Fe- and N-functionalized graphene (HD-FeN/G). The morphology, crystalline structure and elemental composition of HD-FeN/G were characterized. ORR activity was evaluated by using a rotary disk electrode (RDE) electrochemical system. HD improved the loading and distribution of the Fe-Nx composites on graphene. The ORR activity of the as-prepared HD-FeN/G in neutral medium was comparable to that of the state-of-the-art commercial Pt/C and significantly superior to a FeN/G counterpart produced via traditional approach. The ORR electron transfer number of HD-FeN/G was as high as 3.83 ± 0.08, which suggested that ORR catalysis proceeds through a four-electron pathway. HD-FeN/G was used as a cathodic electrocatalyst in microbial fuel cells (MFCs), and the resultant HD-FeN/G-MFC showed comparable voltage output and maximum power density to those of Pt/C-MFC. The HD-FeN/G-MFC achieved a maximum power density of 885 mW m-2, which was much higher than that of FeN/G-MFC (708 mW m-2). These findings demonstrate that HD-FeN/G produced through the novel synthesis strategy proposed in this work would be a good candidate as cathodic electrocatalyst in MFCs.

  7. High efficiency, long life terrestrial solar panel

    NASA Technical Reports Server (NTRS)

    Chao, T.; Khemthong, S.; Ling, R.; Olah, S.

    1977-01-01

    The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was achievable.

  8. HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING NUCLEAR POWER FINAL RECHNICAL REPORT FOR THE PERIOD AUGUST 1, 1999 THROUGH SEPTEMBER 30, 2002 REV. 1

    SciTech Connect

    BROWN,LC; BESENBRUCH,GE; LENTSCH, RD; SCHULTZ,KR; FUNK,JF; PICKARD,PS; MARSHALL,AC; SHOWALTER,SK

    2003-12-01

    monoxide) that are detrimental to precious metal catalyzed fuel cells, as is now recognized by many of the world's largest automobile companies. Thermochemical hydrogen will not contain carbon monoxide as an impurity at any level. Electrolysis, the alternative process for producing hydrogen using nuclear energy, suffers from thermodynamic inefficiencies in both the production of electricity and in electrolytic parts of the process. The efficiency of electrolysis (electricity to hydrogen) is currently about 80%. Electric power generation efficiency would have to exceed 65% (thermal to electrical) for the combined efficiency to exceed the 52% (thermal to hydrogen) calculated for one thermochemical cycle. Thermochemical water-splitting cycles have been studied, at various levels of effort, for the past 35 years. They were extensively studied in the late 70s and early 80s but have received little attention in the past 10 years, particularly in the U.S. While there is no question about the technical feasibility and the potential for high efficiency, cycles with proven low cost and high efficiency have yet to be developed commercially. Over 100 cycles have been proposed, but substantial research has been executed on only a few. This report describes work accomplished during a three-year project whose objective is to ''define an economically feasible concept for production of hydrogen, by nuclear means, using an advanced high temperature nuclear reactor as the energy source.''

  9. High efficiency incandescent lighting

    SciTech Connect

    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.

  10. STARFIRE: a commercial tokamak fusion power plant study

    SciTech Connect

    Not Available

    1980-09-01

    STARFIRE is a 1200 MWe central station fusion electric power plant that utilizes a deuterium-tritium fueled tokamak reactor as a heat source. Emphasis has been placed on developing design features which will provide for simpler assembly and maintenance, and improved safety and environmental characteristics. The major features of STARFIRE include a steady-state operating mode based on continuous rf lower-hybrid current drive and auxiliary heating, solid tritium breeder material, pressurized water cooling, limiter/vacuum system for impurity control and exhaust, high tritium burnup and low vulnerable tritium inventories, superconducting EF coils outside the superconducting TF coils, fully remote maintenance, and a low-activation shield. A comprehensive conceptual design has been developed including reactor features, support facilities and a complete balance of plant. A construction schedule and cost estimate are presented, as well as study conclusions and recommendations.

  11. Dealing with uncertainties in fusion power plant conceptual development

    NASA Astrophysics Data System (ADS)

    Kemp, R.; Lux, H.; Kovari, M.; Morris, J.; Wenninger, R.; Zohm, H.; Biel, W.; Federici, G.

    2017-04-01

    Although the ultimate goal of most current fusion research is to build an economically attractive power plant, the present status of physics and technology does not provide the performance necessary to achieve this goal. Therefore, in order to model how such plants may operate and what their output might be, extrapolations must be made from existing experimental data and technology. However, the expected performance of a plant built to the operating point specifications can only ever be a ‘best guess’. Extrapolations far beyond the current operating regimes are necessarily uncertain, and some important interactions, for example the coupling of conducted power from the scape-off layer to the divertor surface, lack reliable predictive models. This means both that the demands on plant systems at the target operating point can vary significantly from the nominal value, and that the overall plant performance may potentially fall short of design targets. In this contribution we discuss tools and techniques that have been developed to assess the robustness of the operating points for the EU-DEMO tokamak-based demonstration power plant, and the consequences for its design. The aim is to make explicit the design choices and areas where improved modelling and DEMO-relevant experiments will have the greatest impact on confidence in a successful DEMO design.

  12. Advanced high efficiency concentrator cells

    SciTech Connect

    Gale, R. . Varian Research Center)

    1992-06-01

    This report describes research to develop the technology needed to demonstrate a monolithic, multijunction, two-terminal, concentrator solar cell with a terrestrial power conversion efficiency greater than 35%. Under three previous subcontracts, Varian developed many of the aspects of a technology needed to fabricate very high efficiency concentrator cells. The current project was aimed at exploiting the new understanding of high efficiency solar cells. Key results covered in this report are as follows. (1) A 1.93-eV AlGaAs/1.42-eV GaAs metal-interconnected cascade cell was manufactured with a one-sun efficiency at 27.6% at air mass 1.5 (AM1.5) global. (2) A 1.0eV InGaAs cell was fabricated on the reverse'' side of a low-doped GaAs substrate with a one-sun efficiency of 2.5% AM1.5 diffuse and a short-circuit current of 14.4 mA/cm{sup 2}. (3) Small-scale manufacturing of GaAs p/n concentrator cells was attempted and obtained an excellent yield of high-efficiency cells. (4) Grown-in tunnel junction cell interconnects that are transparent and thermally stable using C and Si dopants were developed. 10 refs.

  13. Findings of the US Research Needs Workshop on the Topic of Fusion Power

    SciTech Connect

    Meier, W R; Raffray, A R; Kurtz, R J; Morley, N B; Reiersen, W T; Sharpe, P; Willms, S

    2009-09-16

    The US Department of Energy, Office of Fusion Energy Sciences (OFES) conducted a Research Needs Workshop, referred to as ReNeW, in June 2009. The information developed at this workshop will help OFES develop a plan for US fusion research during the ITER era, roughly the next two decades. The workshop was organized in five Themes, one of which was Harnessing Fusion Power (or Fusion Power for short). The top level goal of the Fusion Power Theme was to identify the research needed to develop the knowledge to design and build, with high confidence, robust and reliable systems that can convert fusion products to useful forms of energy in a reactor environment, including a self-sufficient supply of tritium fuel. Each Theme was subsequently subdivided into Panels to address specific topics. The Fusion Power Panel topics were: fusion fuel cycle; power extraction; materials science; safety and environment; and reliability, availability, maintainability and inspectability (RAMI). Here we present the key findings of the Fusion Power Theme.

  14. Control of a laser inertial confinement fusion-fission power plant

    DOEpatents

    Moses, Edward I.; Latkowski, Jeffery F.; Kramer, Kevin J.

    2015-10-27

    A laser inertial-confinement fusion-fission energy power plant is described. The fusion-fission hybrid system uses inertial confinement fusion to produce neutrons from a fusion reaction of deuterium and tritium. The fusion neutrons drive a sub-critical blanket of fissile or fertile fuel. A coolant circulated through the fuel extracts heat from the fuel that is used to generate electricity. The inertial confinement fusion reaction can be implemented using central hot spot or fast ignition fusion, and direct or indirect drive. The fusion neutrons result in ultra-deep burn-up of the fuel in the fission blanket, thus enabling the burning of nuclear waste. Fuels include depleted uranium, natural uranium, enriched uranium, spent nuclear fuel, thorium, and weapons grade plutonium. LIFE engines can meet worldwide electricity needs in a safe and sustainable manner, while drastically shrinking the highly undesirable stockpiles of depleted uranium, spent nuclear fuel and excess weapons materials.

  15. High efficiency photoionization detector

    DOEpatents

    Anderson, D.F.

    1984-01-31

    A high efficiency photoionization detector is described using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector of the invention. The compound of greatest interest is TMAE which comprises tetrakis(dimethylamino)ethylene which has a measured ionization potential of 5.36 [+-] 0.02 eV, and a vapor pressure of 0.35 torr at 20 C. 6 figs.

  16. High efficiency photoionization detector

    DOEpatents

    Anderson, David F.

    1984-01-01

    A high efficiency photoionization detector using tetraaminoethylenes in a gaseous state having a low ionization potential and a relative photoionization cross section which closely matches the emission spectrum of xenon gas. Imaging proportional counters are also disclosed using the novel photoionization detector of the invention. The compound of greatest interest is TMAE which comprises tetrakis(dimethylamino)ethylene which has a measured ionization potential of 5.36.+-.0.02 eV, and a vapor pressure of 0.35 torr at 20.degree. C.

  17. High efficiency solar panel /HESP/

    NASA Technical Reports Server (NTRS)

    Stella, P. M.; Gay, C.; Uno, F.; Scott-Monck, J.

    1978-01-01

    A family of high efficiency, weldable silicon solar cells, incorporating nearly every feature of advanced cell technology developed in the past four years, was produced and subjected to space qualification testing. This matrix contained both field and non-field cells ranging in thickness from 0.10 mm to 0.30 mm, and in base resistivity from nominal two to one hundred ohm-cm. Initial power outputs as high as 20 mW/sq cm (14.8% AM0 efficiency) were produced by certain cell types within the matrix.

  18. YLIFE-2 inertial fusion energy power plant design

    NASA Astrophysics Data System (ADS)

    Moir, R. W.

    1992-03-01

    The HYLIFE-2 inertial fusion power plant design study uses a liquid fall, in the form of jets, to protect the first structural wall from neutron damage, x rays, and blast to provide a 30-y lifetime. HYLIFE-1 used liquid lithium. HYLIFE-2 avoids the fire hazard of lithium by using a molten salt composed of fluorine, lithium, and beryllium (Li2BeF4) called Flibe. Access for heavy-ion beams is provided. Calculations for assumed heavy-ion beam performance show a nominal gain of 70 at 5 MJ producing 350 MJ, about 5.2 times less yield than the 1.8 GJ from a driver energy of 4.5 MJ with gain of 400 for HYLIFE-1. The nominal 1 GWe of power can be maintained by increasing the repetition rate by a factor of about 5.2, from 1.5 to 8 Hz. A higher repetition rate requires faster re-establishment of the jets after a shot, which can be accomplished in part by decreasing the jet fall height and increasing the jet flow velocity. In addition, although not adequately considered for HYLIFE-1, there is liquid splash that must be forcibly cleared because gravity is too slow, at higher repetition rates than 1 Hz. Splash removal is accomplished in the central region by oscillating jet flows. The cost of electricity is estimated to be 0.09 $/kWh in constant 1988 dollars, about twice that of future coal and light water reactor nuclear power. The driver beam cost is about one-half the total cost, that is, a zero cost driver would give a calculated cost of electricity of 0.045 $/kWh.

  19. HYLIFE-2 inertial confinement: Fusion power plant design

    NASA Astrophysics Data System (ADS)

    Moir, R. W.

    1990-12-01

    The HYLIFE-2 inertial fusion power plant design study uses a liquid fall, in the form of jets to protect the first structural wall from neutron damage, x rays, and blast to provide a 30-y lifetime. HYLIFE-1 used liquid lithium. HYLIFE 2 avoids the fire hazard of lithium by using a molten salt composed of fluorine, lithium, and beryllium (Li2BeF4) called Flibe. Access for heavy-ion beams is provided. Calculations for assumed heavy-ion beam performance show a nominal gain of 70 at 5 MJ producing 350 MJ, about 5.2 times less yield than the 1.8 GJ from a driver energy of 4.5 MJ with gain of 400 for HYLIFE-1. The nominal 1 GWe of power can be maintained by increasing the repetition rate by a factor of about 5.2, from 1.5 to 8 Hz. A higher repetition rate requires faster re-establishment of the jets after a shot, which can be accomplished in part by decreasing the jet fall height and increasing the jet flow velocity. Multiple chambers may be required. In addition, although not considered for HYLIFE-1, there is undoubtedly liquid splash that must be forcibly cleared because gravity is too slow, especially at high repetition rates. Splash removal can be accomplished by either pulsed or oscillating jet flows. The cost of electricity is estimated to be 0.09 $/kW x h in constant 1988 dollars, about twice that of future coal and light water reactor nuclear power. The driver beam cost is about one-half the total cost.

  20. High Efficiency Cell Development

    NASA Technical Reports Server (NTRS)

    Carbajal, B. G.

    1979-01-01

    The specific activity was to improve the tandem junction Cell (TJC) as a high efficiency solar cell. The TJC development was to be consistent with module assembly and should contribute to the overall goals of the Low-Cost Solar Array Project. During 1978, TJC efficiency improved from approximately 11 percent to approximately 16 percent (AMI). Photogenerated current densities in excess of 42 mA/sq cm were observed at AMO. Open circuit voltages as high as 0.615 V were measured at AMO. Fill factor was only 0.68 - 0.75 due to a nonoptimum metal contact design. A device model was conceived in which the solar cell is modelled as a transitor. There are virtually no interconnect or packaging factor systems and the TJC is compatible with all conventional module fabrication systems. A modification of the TJC, the Front Surface Field (FSF) cell, was also explored.

  1. Power Plant and Fusion Chamber Considerations for Fast Ignition

    SciTech Connect

    Meier, W R; Hogan, W J

    2005-03-10

    A large number of inertial fusion energy (IFE) chamber concepts have been proposed and analyzed to various levels of detail [1, 2]. A smaller number of detailed power plant design studies (i.e., studies considering self-consistent integration of targets, drivers and chambers) have also been completed for both direct-drive and indirect-drive, central ignition (CI) targets [3-5]. There have not been any comparable studies of fusion chambers or integrated power plants for fast-ignition (FI) based IFE. Some specific aspects (advantages and issues) have been previously describe [6, 7], but not to the level of detail of the large integrated design studies. In this paper, we review current understanding of chamber design and power plant features for fast-ignition. We approach this topic by asking what chamber and power plant issues and features will be different for fast ignition compared to central ignition. In this article, we consider first wall and final optics design issues for various chamber concepts with direct and indirect drive FI targets, while target manufacture and injection issues are considered in another paper in this special issue [8]. If it is found that the ignitor beams can efficiently penetrate the plasma that is blown off the fuel capsule surface during the compression phase, the FI targets may look much like CI targets. In this case the fusion chamber and final optics issues are likely to be very similar to those for CI targets, except for the final optics of the ignitor beams. It is more likely that the efficiency of transferring ignitor beam energy through the blow-off plasma to the ignition spot fuel will be so low that whatever advantage fast ignition has in reducing required compression driver energy will be more than offset by the size and, therefore, cost of the ignitor lasers themselves. Therefore, it has been proposed to use a cone of high-Z material [9] to shield the ignitor beam line-of-sight from the blow-off plasma and possibly help

  2. Challenges of Fusion Power Plant Licensing: Differences and Commonalities with Existing Systems

    SciTech Connect

    L. El-Guebaly; L. Cadwallader; W. Sowder

    2011-08-01

    At present, there are no regulatory guidelines to follow for US fusion power plant construction and operation. Thus far, the Department of Energy (DOE) has been regulating existing fusion experiments, following the 1996-1999 DOE Fusion Standards and using the spirit of the ASME (American Society of Mechanical Engineers) code. Considering this reality, a few options emerged for licensing ARIES-type power plants and the like. Developing new fusion-specific regulations stands out as the most logical option, but requires well-coordinated effort between DOE, regulatory agencies, and the fusion community with considerable funding and long lead-time. Nevertheless, a few recent developments seem promising: (1) The US Nuclear Regulatory Commission (NRC) plans to assert regulatory jurisdiction over commercial fusion devices, and (2) the ongoing effort within ASME will develop rules for the construction of fusion-energy-related components. The most recent NRC, ASME and fusion licensing developments are reviewed in this paper. In addition, an interesting comparison with ITER was made to foresee how US fusion power plants could leverage from ITER.

  3. Commercial objectives, technology transfer, and systems analysis for fusion power development

    NASA Astrophysics Data System (ADS)

    Dean, Stephen O.

    1988-03-01

    Fusion is an essentially inexhaustible source of energy that has the potential for economically attractive commercial applications with excellent safety and environmental characteristics. The primary focus for the fusion-energy development program is the generation of centralstation electricity. Fusion has the potential, however, for many other applications. The fact that a large fraction of the energy released in a DT fusion reaction is carried by high-energy neutrons suggests potentially unique applications. These include breeding of fissile fuels, production of hydrogen and other chemical products, transmutation or “burning” of various nuclear or chemical wastes, radiation processing of materials, production of radioisotopes, food preservation, medical diagnosis and medical treatment, and space power and space propulsion. In addition, fusion R&D will lead to new products and new markets. Each fusion application must meet certain standards of economic and safety and environmental attractiveness. For this reason, economics on the one hand, and safety and environment and licensing on the other hand, are the two primary criteria for setting long-range commercial fusion objectives. A major function of systems analysis is to evaluate the potential of fusion against these objectives and to help guide the fusion R&D program toward practical applications. The transfer of fusion technology and skills from the national laboratories and universities to industry is the key to achieving the long-range objective of commercial fusion applications.

  4. High Efficiency Lithium-Thionyl Chloride Cell.

    DTIC Science & Technology

    1982-04-01

    AD-Al14 672 HONEYWELL POWER SOURCES CENTER HORSHAM PA F/S 10/3 HIGH EFFICIENCY LITHIUM - THIONYL CHLORIDE CELLo(U) APR 82 N DODDAPANEN! OAAK20-81-C...CHART NATIONAl BUREAU OF STANDARDS 1963 A Research and Development Technical Report DELET-TR-81-0381-3 HIGH EFFICIENCY LITHIUM - THIONYL CHLORIDE CELL...reverse aide it necessary and Identify by block number) Thionyl chloride , lithium , high discharge rates, low temperatures, catalysis, cyclic

  5. On the wanderings of a quantum chemist in the world of fusion power and politics

    SciTech Connect

    Monkhorst, H.J.

    2000-03-05

    Ruminations by a quantum chemist are offered on his forays into the treacherous territory of the global fusion power research community. His and a colleague's proposal for a colliding beam fusion reactor is explained. His experiences hold general lessons about the treatment an innocent scientist can expect when he challenges the entrenched modus operandi of a large scientific/engineering establishment.

  6. Comment on ‘On the fusion triple product and fusion power gain of tokamak pilot plants and reactors’, by A. Costley

    NASA Astrophysics Data System (ADS)

    Biel, W.; Lackner, K.; Sauter, O.; Wenninger, R.; Zohm, H.

    2017-03-01

    In this comment, we discuss the arguments raised in two recent papers (Costley 2016 Nucl. Fusion 56 066003, Costley et al 2015 Nucl. Fusion 55 033001) on the claimed size independence of fusion power, triple product and fusion gain in tokamak reactors, and we show that all these three quantities actually do depend on the size of the tokamak, when distinguishing between independent input parameters (design parameters) and output quantities, and when taking into account technological limitations.

  7. High-efficiency CARM

    SciTech Connect

    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.

  8. High Efficiency Engine Technologies Program

    SciTech Connect

    Rich Kruiswyk

    2010-07-13

    Caterpillar's Product Development and Global Technology Division carried out a research program on waste heat recovery with support from DOE (Department of Energy) and the DOE National Energy Technology Laboratory. The objective of the program was to develop a new air management and exhaust energy recovery system that would demonstrate a minimum 10% improvement in thermal efficiency over a base heavy-duty on-highway diesel truck engine. The base engine for this program was a 2007 C15 15.2L series-turbocharged on-highway truck engine with a LPL (low-pressure loop) exhaust recirculation system. The focus of the program was on the development of high efficiency turbomachinery and a high efficiency turbocompound waste heat recovery system. The focus of each area of development was as follows: (1) For turbine stages, the focus was on investigation and development of technologies that would improve on-engine exhaust energy utilization compared to the conventional radial turbines in widespread use today. (2) For compressor stages, the focus was on investigating compressor wheel design parameters beyond the range typically utilized in production, to determine the potential efficiency benefits thereof. (3) For turbocompound, the focus was on the development of a robust bearing system that would provide higher bearing efficiencies compared to systems used in turbocompound power turbines in production. None of the turbocharger technologies investigated involved addition of moving parts, actuators, or exotic materials, thereby increasing the likelihood of a favorable cost-value tradeoff for each technology. And the turbocompound system requires less hardware addition than competing bottoming cycle technologies, making it a more attractive solution from a cost and packaging standpoint. Main outcomes of the program are as follows: (1) Two turbine technologies that demonstrated up to 6% improvement in turbine efficiency on gas stand and 1-3% improvement in thermal efficiency in

  9. High efficiency gas burner

    DOEpatents

    Schuetz, Mark A.

    1983-01-01

    A burner assembly provides for 100% premixing of fuel and air by drawing the air into at least one high velocity stream of fuel without power assist. Specifically, the nozzle assembly for injecting the fuel into a throat comprises a plurality of nozzles in a generally circular array. Preferably, swirl is imparted to the air/fuel mixture by angling the nozzles. The diffuser comprises a conical primary diffuser followed by a cusp diffuser.

  10. Tritium Breeding Blanket for a Commercial Fusion Power Plant - A System Engineering Assessment

    SciTech Connect

    Meier, Wayne R.

    2014-04-14

    The goal of developing a new source of electric power based on fusion has been pursued for decades. If successful, future fusion power plants will help meet growing world-wide demand for electric power. A key feature and selling point for fusion is that its fuel supply is widely distributed globally and virtually inexhaustible. Current world-wide research on fusion energy is focused on the deuterium-tritium (DT for short) fusion reaction since it will be the easiest to achieve in terms of the conditions (e.g., temperature, density and confinement time of the DT fuel) required to produce net energy. Over the past decades countless studies have examined various concepts for TBBs for both magnetic fusion energy (MFE) and inertial fusion energy (IFE). At this time, the key organizations involved are government sponsored research organizations world-wide. The near-term focus of the MFE community is on the development of TBB mock-ups to be tested on the ITER tokamak currently under construction in Caderache France. TBB concepts for IFE tend to be different from MFE primarily due to significantly different operating conditions and constraints. This report focuses on longer-term commercial power plants where the key stakeholders include: electric utilities, plant owner and operator, manufacturer, regulators, utility customers, and in-plant subsystems including the heat transfer and conversion systems, fuel processing system, plant safety systems, and the monitoring control systems.

  11. CONFERENCE REPORT: Summary of the 8th IAEA Technical Meeting on Fusion Power Plant Safety

    NASA Astrophysics Data System (ADS)

    Girard, J. Ph.; Gulden, W.; Kolbasov, B.; Louzeiro-Malaquias, A.-J.; Petti, D.; Rodriguez-Rodrigo, L.

    2008-01-01

    Reports were presented covering a selection of topics on the safety of fusion power plants. These included a review on licensing studies developed for ITER site preparation surveying common and non-common issues (i.e. site dependent) as lessons to a broader approach for fusion power plant safety. Several fusion power plant models, spanning from accessible technology to more advanced-materials based concepts, were discussed. On the topic related to fusion-specific technology, safety studies were reported on different concepts of breeding blanket modules, tritium handling and auxiliary systems under normal and accident scenarios' operation. The testing of power plant relevant technology in ITER was also assessed in terms of normal operation and accident scenarios, and occupational doses and radioactive releases under these testings have been determined. Other specific safety issues for fusion have also been discussed such as availability and reliability of fusion power plants, dust and tritium inventories and component failure databases. This study reveals that the environmental impact of fusion power plants can be minimized through a proper selection of low activation materials and using recycling technology helping to reduce waste volume and potentially open the route for its reutilization for the nuclear sector or even its clearance into the commercial circuit. Computational codes for fusion safety have been presented in support of the many studies reported. The on-going work on establishing validation approaches aiming at improving the prediction capability of fusion codes has been supported by experimental results and new directions for development have been identified. Fusion standards are not available and fission experience is mostly used as the framework basis for licensing and target design for safe operation and occupational and environmental constraints. It has been argued that fusion can benefit if a specific fusion approach is implemented, in particular

  12. Path to Market for Compact Modular Fusion Power Cores

    NASA Astrophysics Data System (ADS)

    Woodruff, Simon; Baerny, Jennifer K.; Mattor, Nathan; Stoulil, Don; Miller, Ronald; Marston, Theodore

    2012-08-01

    The benefits of an energy source whose reactants are plentiful and whose products are benign is hard to measure, but at no time in history has this energy source been more needed. Nuclear fusion continues to promise to be this energy source. However, the path to market for fusion systems is still regularly a matter for long-term (20 + year) plans. This white paper is intended to stimulate discussion of faster commercialization paths, distilling guidance from investors, utilities, and the wider energy research community (including from ARPA-E). There is great interest in a small modular fusion system that can be developed quickly and inexpensively. A simple model shows how compact modular fusion can produce a low cost development path by optimizing traditional systems that burn deuterium and tritium, operating not only at high magnetic field strength, but also by omitting some components that allow for the core to become more compact and easier to maintain. The dominant hurdles to the development of low cost, practical fusion systems are discussed, primarily in terms of the constraints placed on the cost of development stages in the private sector. The main finding presented here is that the bridge from DOE Office of Science to the energy market can come at the Proof of Principle development stage, providing the concept is sufficiently compact and inexpensive that its development allows for a normal technology commercialization path.

  13. Optimization of the SHX Fusion Powered Transatmospheric Propulsion Concept

    NASA Technical Reports Server (NTRS)

    Adams, Robert B.; Landrum, D. Brian

    2001-01-01

    Existing propulsion technology has not achieved cost effective payload delivery rates to low earth orbit. A fusion based propulsion system, denoted as the Simultaneous Heating and eXpansion (SHX) engine, has been proposed in earlier papers. The SHX couples energy generated by a fusion reactor to the engine flowpath by use of coherent beam emitters. A quasi-one-dimensional flow model was used to quantify the effects of area expansion and energy input on propulsive efficiency for several beam models. Entropy calculations were included to evaluate the lost work in the system.

  14. Fusion

    NASA Astrophysics Data System (ADS)

    Herman, Robin

    1990-10-01

    The book abounds with fascinating anecdotes about fusion's rocky path: the spurious claim by Argentine dictator Juan Peron in 1951 that his country had built a working fusion reactor, the rush by the United States to drop secrecy and publicize its fusion work as a propaganda offensive after the Russian success with Sputnik; the fortune Penthouse magazine publisher Bob Guccione sank into an unconventional fusion device, the skepticism that met an assertion by two University of Utah chemists in 1989 that they had created "cold fusion" in a bottle. Aimed at a general audience, the book describes the scientific basis of controlled fusion--the fusing of atomic nuclei, under conditions hotter than the sun, to release energy. Using personal recollections of scientists involved, it traces the history of this little-known international race that began during the Cold War in secret laboratories in the United States, Great Britain and the Soviet Union, and evolved into an astonishingly open collaboration between East and West.

  15. Modelling the power deposition into a spherical tokamak fusion power plant

    NASA Astrophysics Data System (ADS)

    Windsor, C. G.; Morgan, J. G.; Buxton, P. F.; Costley, A. E.; Smith, G. D. W.; Sykes, A.

    2017-03-01

    Numerical studies have been made to improve the performance of the central column of a superconducting spherical tokamak fusion pilot plant. The assumed neutron shield includes concentric layers of tungsten carbide and water. The relative thickness of the water layers was varied and a minimum power deposition was found at about 17% of water. It was found advantageous to have an approximately 1.7 times thicker water layer next to the core and a similarly thinner layer next to the plasma. The use of tungsten boride instead of tungsten carbide was shown to make an improvement especially if placed close to the central superconducting core, the inner layer alone reducing the power deposition by 29%. Engineering features such as a central steel tie-bar, an insulating thermal vacuum gap, a wall gap next to the plasma and knowledge of the vertical energy distribution are essential to a successful design and their effects on the power deposition are shown in an appendix. The results have been fitted to model distributions and incorporated into the Tokamak Energy System Code, which can then give predictions of the power deposition as a function of other parameters such as the plasma major radius and the maximum magnetic field permitted on the superconductors.

  16. High efficiency motor rewind study

    NASA Astrophysics Data System (ADS)

    Wallace, A. K.; Spee, R.

    1991-02-01

    The objective of performing this work was to evaluate a new technology used for rewinding electric motors. Motor performance evaluation was conducted at the motor test facility at Oregon State University. The test program consisted of comparing new high efficiency motor technology and standard rewind technology with the Unity-Plus system. The Unity-Plus configuration exhibited reduced efficiency over the complete load range compared to the other motors. Appropriately sized capacitors connected to the terminals of the conventional induction motor produced the same power factor improvement as the Unity-Plus system. Torque production and torque pulsation were very similar for all systems. The Unity-Plus configuration drew lower starting currents but the duration of the starting transient was increased. Motor temperature rise was about the same for all systems. Noise levels were about the same in all systems. Although determination of time to failure was not undertaken, the expected lifetime of the Unit-Plus system is probably less due to higher capacitor stress and higher insulation stress. The investigation concludes that a conventional induction motor with terminal capacitors is the most acceptable way of obtaining good efficiency and power factor and the Unity-Plus system cannot be recommended on the basis of any of the evaluation criteria used in this study.

  17. Radio-frequency energy in fusion power generation

    SciTech Connect

    Lawson, J.Q.; Becraft, W.R.; Hoffman, D.J.

    1983-01-01

    The history of radio-frequency (rf) energy in fusion experiments is reviewed, and the status of current efforts is described. Potential applications to tasks other than plasma heating are described, as are the research and development needs of rf energy technology.

  18. The NASA-Lewis program on fusion energy for space power and propulsion, 1958-1978

    NASA Technical Reports Server (NTRS)

    Schulze, Norman R.; Roth, J. Reece

    1990-01-01

    An historical synopsis is provided of the NASA-Lewis research program on fusion energy for space power and propulsion systems. It was initiated to explore the potential applications of fusion energy to space power and propulsion systems. Some fusion related accomplishments and program areas covered include: basic research on the Electric Field Bumpy Torus (EFBT) magnetoelectric fusion containment concept, including identification of its radial transport mechanism and confinement time scaling; operation of the Pilot Rig mirror machine, the first superconducting magnet facility to be used in plasma physics or fusion research; operation of the Superconducting Bumpy Torus magnet facility, first used to generate a toroidal magnetic field; steady state production of neutrons from DD reactions; studies of the direct conversion of plasma enthalpy to thrust by a direct fusion rocket via propellant addition and magnetic nozzles; power and propulsion system studies, including D(3)He power balance, neutron shielding, and refrigeration requirements; and development of large volume, high field superconducting and cryogenic magnet technology.

  19. High-power and highly efficient diode-cladding-pumped holmium-doped fluoride fiber laser operating at 2.94 microm.

    PubMed

    Jackson, Stuart D

    2009-08-01

    A high-power diode-cladding-pumped Ho(3+), Pr(3+)-doped fluoride glass fiber laser is demonstrated. The laser produced a maximum output power of 2.5 W at a slope efficiency of 32% using diode lasers emitting at 1,150 nm. The long-emission wavelength of 2.94 microm measured at maximum pump power, which is particularly suited to medical applications, indicates that tailoring of the proportion of Pr(3+) ions can provide specific emission wavelengths while providing sufficient de-excitation of the lower laser level.

  20. Reply to ‘Comment “On the fusion triple product and fusion power gain of tokamak pilot plants and reactors”’

    NASA Astrophysics Data System (ADS)

    Costley, A. E.; Buxton, P. F.; Hugill, J.

    2017-03-01

    In reply to the Comment by Biel et al (2016 Nucl. Fusion 57 038001) on our recent papers Costley et al (2015 Nucl Fusion 55 033001) and Costley (2016 Nucl. Fusion 56 066003), we point out that the fusion triple product, nTτ E, and fusion power gain, Q fus, cannot be expressed solely in terms of independent engineering design variables such as major radius, R, and toroidal field, B; output performance variables such as normalised beta, β N, safety factor, q, and fusion power P fus, have to be invoked. Further, we show that the density limit has the effect of largely cancelling the size dependence in nTτ E and Q fus, which would otherwise be present, when these parameters are expressed in terms of P fus. Considerations of engineering aspects are also briefly discussed.

  1. Apparatus and method for extracting power from energetic ions produced in nuclear fusion

    DOEpatents

    Fisch, N.J.; Rax, J.M.

    1994-12-20

    An apparatus and method of extracting power from energetic ions produced by nuclear fusion in a toroidal plasma to enhance respectively the toroidal plasma current and fusion reactivity. By injecting waves of predetermined frequency and phase traveling substantially in a selected poloidal direction within the plasma, the energetic ions become diffused in energy and space such that the energetic ions lose energy and amplify the waves. The amplified waves are further adapted to travel substantially in a selected toroidal direction to increase preferentially the energy of electrons traveling in one toroidal direction which, in turn, enhances or generates a toroidal plasma current. In an further adaptation, the amplified waves can be made to preferentially increase the energy of fuel ions within the plasma to enhance the fusion reactivity of the fuel ions. The described direct, or in situ, conversion of the energetic ion energy provides an efficient and economical means of delivering power to a fusion reactor. 4 figures.

  2. Apparatus and method for extracting power from energetic ions produced in nuclear fusion

    DOEpatents

    Fisch, Nathaniel J.; Rax, Jean M.

    1994-01-01

    An apparatus and method of extracting power from energetic ions produced by nuclear fusion in a toroidal plasma to enhance respectively the toroidal plasma current and fusion reactivity. By injecting waves of predetermined frequency and phase traveling substantially in a selected poloidal direction within the plasma, the energetic ions become diffused in energy and space such that the energetic ions lose energy and amplify the waves. The amplified waves are further adapted to travel substantially in a selected toroidal direction to increase preferentially the energy of electrons traveling in one toroidal direction which, in turn, enhances or generates a toroidal plasma current. In an further adaptation, the amplified waves can be made to preferentially increase the energy of fuel ions within the plasma to enhance the fusion reactivity of the fuel ions. The described direct, or in situ, conversion of the energetic ion energy provides an efficient and economical means of delivering power to a fusion reactor.

  3. OSIRIS and SOMBRERO Inertial Fusion Power Plant Designs, Volume 1: Executive Summary & Overview

    SciTech Connect

    Meier, W. R.; Bieri, R. L.; Monsler, M. J.; Hendricks, C.D.; Laybourne, P.; Shillito, K. R.

    1992-03-01

    This is a comprehensive design study of two Inertial Fusion Energy (IFE) electric power plants. Conceptual designs are presented for a fusion reactor (called Osiris) using an induction-linac heavy-ion beam driver, and another (called SOMBRERO) using a KrF laser driver. The designs covered all aspects of IFE power plants, including the chambers, heat transport and power conversion systems, balance-of-plant facilities, target fabrication, target injection and tracking, as well as the heavy-ion and KrF drivers. The point designs were assessed and compared in terms of their environmental & safety aspects, reliability and availability economics, and technology development needs.

  4. OSIRIS and SOMBRERO Inertial Fusion Power Plant Designs, Volume 2: Designs, Assessments, and Comparisons

    SciTech Connect

    Meier, W. R.; Bieri, R. L.; Monsler, M. J.; Hendricks, C. D.; Laybourne, P.; Shillito, K. R.

    1992-03-01

    This is a comprehensive design study of two Inertial Fusion Energy (IFE) electric power plants. Conceptual designs are presented for a fusion reactor (called Osiris) using an induction-linac heavy-ion beam driver, and another (called SOMBRERO) using a KrF laser driver. The designs covered all aspects of IFE power plants, including the chambers, heat transport and power conversion systems, balance-of-plant facilities, target fabrication, target injection and tracking, as well as the heavy-ion and KrF drivers. The point designs were assessed and compared in terms of their environmental & safety aspects, reliability and availability, economics, and technology development needs.

  5. Flywheel induction motor-generator for magnet power supply in small fusion device.

    PubMed

    Hatakeyma, S; Yoshino, F; Tsutsui, H; Tsuji-Iio, S

    2016-04-01

    A flywheel motor-generator (MG) for the toroidal field (TF) coils of a small fusion device was developed which utilizes a commercially available squirrel-cage induction motor. Advantages of the MG are comparably-long duration, quick power response, and easy implementation of power control compared with conventional capacitor-type power supply. A 55-kW MG was fabricated, and TF coils of a small fusion device were energized. The duration of the current flat-top was extended to 1 s which is much longer than those of conventional small devices (around 10-100 ms).

  6. Flywheel induction motor-generator for magnet power supply in small fusion device

    NASA Astrophysics Data System (ADS)

    Hatakeyma, S.; Yoshino, F.; Tsutsui, H.; Tsuji-Iio, S.

    2016-04-01

    A flywheel motor-generator (MG) for the toroidal field (TF) coils of a small fusion device was developed which utilizes a commercially available squirrel-cage induction motor. Advantages of the MG are comparably-long duration, quick power response, and easy implementation of power control compared with conventional capacitor-type power supply. A 55-kW MG was fabricated, and TF coils of a small fusion device were energized. The duration of the current flat-top was extended to 1 s which is much longer than those of conventional small devices (around 10-100 ms).

  7. Channel Temperature Model for Microwave AlGaN/GaN HEMTs on SiC and Sapphire MMICs in High Power, High Efficiency SSPAs

    NASA Technical Reports Server (NTRS)

    Freeman, Jon C.

    2004-01-01

    A key parameter in the design trade-offs made during AlGaN/GaN HEMTs development for microwave power amplifiers is the channel temperature. An accurate determination can, in general, only be found using detailed software; however, a quick estimate is always helpful, as it speeds up the design cycle. This paper gives a simple technique to estimate the channel temperature of a generic microwave AlGaN/GaN HEMT on SiC or Sapphire, while incorporating the temperature dependence of the thermal conductivity. The procedure is validated by comparing its predictions with the experimentally measured temperatures in microwave devices presented in three recently published articles. The model predicts the temperature to within 5 to 10 percent of the true average channel temperature. The calculation strategy is extended to determine device temperature in power combining MMICs for solid-state power amplifiers (SSPAs).

  8. Fusion power demonstration - a baseline for the mirror engineering test reactor

    SciTech Connect

    Henning, C.D.; Logan, B.G.; Neef, W.S.; Dorn, D.; Clarkson, I.R.; Carpenter, T.; Gordon, J.D.; Campbell, R.B.; Hsu, P.; Nelson, D.

    1983-12-02

    Developing a definition of an engineering test reactor (ETR) is a current goal of the Office of Fusion Energy (OFE). As a baseline for the mirror ETR, the Fusion Power Demonstration (FPD) concept has been pursued at Lawrence Livermore National Laboratory (LLNL) in cooperation with Grumman Aerospace, TRW, and the Idaho National Engineering Laboratory. Envisioned as an intermediate step to fusion power applications, the FPD would achieve DT ignition in the central cell, after which blankets and power conversion would be added to produce net power. To achieve ignition, a minimum central cell length of 67.5 m is needed to supply the ion and alpha particles radial drift pumping losses in the transition region. The resulting fusion power is 360 MW. Low electron-cyclotron heating power of 12 MW, ion-cyclotron heating of 2.5 MW, and a sloshing ion beam power of 1.0 MW result in a net plasma Q of 22. A primary technological challenge is the 24-T, 45-cm bore choke coil, comprising a copper hybrid insert within a 15 to 18 T superconducting coil.

  9. High-power and high-efficiency diode-pumped Nd:LuYAG mixed crystal lasers operating at 939 and 946  nm.

    PubMed

    Cui, Qin; Lan, Jinglong; Lin, Zhi; Xu, Bin; Xu, Huiying; Cai, Zhiping; Xu, Xiaodong; Zhang, Jian; Xu, Jun

    2016-09-10

    We report on high-performance infrared lasers at 0.94 μm based on quasi-three-level transition of F3/24→I9/24 in Nd:LuYAG mixed crystal, for the first time to our knowledge. The maximum output power was achieved to 5.64 W with slope efficiency of approximately 52.5% at 946 nm. The simultaneous dual-wavelength laser at 939 and 946 nm is also obtained with maximum output power of 3.61 W and slope efficiency of 34.8% by introducing a glass etalon into the cavity. Moreover, a 2.0-W single-wavelength laser at 939 nm can be further attained by suitably tilting the etalon. Using a Cr:YAG saturable absorber, Q-switched laser operation is realized with maximum average output power of 0.68 W and the narrowest pulse width of 8.4 ns, which results in the maximum single pulse energy of approximately 55.3 μJ and the maximum pulse peak power of approximately 6.15 kW. Finally, thermal focal length of the laser crystal is estimated by using a flat-flat laser cavity.

  10. Taming the heat flux problem: Advanced divertors towards fusion power

    SciTech Connect

    Kotschenreuther, M.; Mahajan, S.; Valanju, P. M.; Covele, B.; Waelbroeck, F. L.; Canik, John M.; LaBombard, Brian

    2015-09-11

    The next generation fusion machines are likely to face enormous heat exhaust problems. In addition to summarizing major issues and physical processes connected with these problems, we discuss how advanced divertors, obtained by modifying the local geometry, may yield workable solutions. We also point out that: (1) the initial interpretation of recent experiments show that the advantages, predicted, for instance, for the X-divertor (in particular, being able to run a detached operation at high pedestal pressure) correlate very well with observations, and (2) the X-D geometry could be implemented on ITER (and DEMOS) respecting all the relevant constraints. As a result, a roadmap for future research efforts is proposed.

  11. A Battery Powered Highly Efficient Exterior Lighting System Using Low Pressure Sodium Vapour Lamp for Use in Non-electrified Areas

    NASA Astrophysics Data System (ADS)

    Ray, Kalyankumar; Golder, Sujit; Mazumdar, Saswati

    Innumerous attempts to solve the problems of exterior lighting in non-electrified areas of India e.g. highways, hilly areas, rural areas of delta regions have been made in the last two decades. A solar powered lighting system with 11 watt or 18 watt Compact Fluorescent Lamps (CFL) have been mounted in street light fixtures at some places but insufficient amount of light do not always serve the required need of the users specially in foggy weather. This paper reports the development of a battery powered lighting system fitted with a 35 Watt Low Pressure Sodium Vapour (SOX) lamp. It is extremely beneficial in remote non-electrified areas for its far higher light output when fitted in street light or flood light fixtures. The battery may be charged from any non-conventional energy source and is connected to the electronic circuit, which operates at high frequency. The light output of this system fitted with a solar photovoltaic array (SPVA) and the corresponding battery power have been measured and the results have been reported in this paper. This high intensity lighting system has a wide application potential in developing countries throughout the world.

  12. Fusion power production from TFTR plasmas fueled with deuterium and tritium

    SciTech Connect

    Strachan, J. D.; Adler, H.; Alling, P.; Ancher, C.; Anderson, H.; Anderson, J. L.; Ashcroft, D.; Barnes, Cris W.; Barnes, G.; Batha, S.; Bell, M. G.; Bell, R.; Bitter, M.; Blanchard, W.; Bretz, N. L.; Budny, R.; Bush, C. E.; Camp, R.; Caorlin, M.; Cauffman, S.; Chang, Z.; Cheng, C. Z.; Collins, J.; Coward, G.; Darrow, D. S.; DeLooper, J.; Duong, H.; Dudek, L.; Durst, R.; Efthimion, P. C.; Ernst, D.; Fisher, R.; Fonck, R. J.; Fredrickson, E.; Fromm, N.; Fu, G. Y.; Furth, H. P.; Gentile, C.; Gorelenkov, N.; Grek, B.; Grisham, L. R.; Hammett, G.; Hanson, G. R.; Hawryluk, R. J.; Heidbrink, W.; Herrmann, H. W.; Hill, K. W.; Hosea, J.; Hsuan, H.; Janos, A.; Jassby, D. L.; Jobes, F. C.; Johnson, D. W.; Johnson, L. C.; Kamperschroer, J.; Kugel, H.; Lam, N. T.; LaMarche, P. H.; Loughlin, M. J.; LeBlanc, B.; Leonard, M.; Levinton, F. M.; Machuzak, J.; Mansfield, D. K.; Martin, A.; Mazzucato, E.; Majeski, R.; Marmar, E.; McChesney, J.; McCormack, B.; McCune, D. C.; McGuire, K. M.; McKee, G.; Meade, D. M.; Medley, S. S.; Mikkelsen, D. R.; Mueller, D.; Murakami, M.; Nagy, A.; Nazikian, R.; Newman, R.; Nishitani, T.; Norris, M.; O’Connor, T.; Oldaker, M.; Osakabe, M.; Owens, D. K.; Park, H.; Park, W.; Paul, S. F.; Pearson, G.; Perry, E.; Petrov, M.; Phillips, C. K.; Pitcher, S.; Ramsey, A. T.; Rasmussen, D. A.; Redi, M. H.; Roberts, D.; Rogers, J.; Rossmassler, R.; Roquemore, A. L.; Ruskov, E.; Sabbagh, S. A.; Sasao, M.; Schilling, G.; Schivell, J.; Schmidt, G. L.; Scott, S. D.; Sissingh, R.; Skinner, C. H.; Snipes, J. A.; Stevens, J.; Stevenson, T.; Stratton, B. C.; Synakowski, E.; Tang, W.; Taylor, G.; Terry, J. L.; Thompson, M. E.; Tuszewski, M.; Vannoy, C.; von Halle, A.; von Goeler, S.; Voorhees, D.; Walters, R. T.; Wieland, R.; Wilgen, J. B.; Williams, M.; Wilson, J. R.; Wong, K. L.; Wurden, G. A.; Yamada, M.; Young, K. M.; Zarnstorff, M. C.; Zweben, S. J.

    1994-05-01

    Peak fusion power production of 6.2 ± 0.4 MW has been achieved in TFTR plasmas heated by deuterium and tritium neutral beams at a total power of 29.5 MW. These plasmas have an inferred central fusion alpha particle density of 1.2 x 1017 m ₋3 without the appearance of either disruptive magnetohydrodynamics events or detectable changes in Alfvén wave activity. The measured loss rate of energetic alpha particles agreed with the approximately 5% losses expected from alpha particles which are born on unconfined orbits.

  13. Fusion power production from TFTR plasmas fueled with deuterium and tritium*

    SciTech Connect

    Strachan, J. D.; Adler, H.; Alling, P.; Synakowski, E.

    1994-03-01

    Peak fusion power production of 6.2 ± 0.4 MW has been achieved in TFTR plasmas heated by deuterium and tritium neutral beams at a total power of 29.5 MW. These plasmas have an inferred central fusion alpha particle density of 1.2 x 1017 m₋3 without the appearance of either disruptive MHD events or detectable changes in Alfvén wave activity. The measured loss rate of energetic alpha particles agreed with the approximately 5% losses expected from alpha particles which are born on unconfined orbits.

  14. Z-inertial fusion energy: power plant final report FY 2006.

    SciTech Connect

    Anderson, Mark; Kulcinski, Gerald; Zhao, Haihua; Cipiti, Benjamin B.; Olson, Craig Lee; Sierra, Dannelle P.; Meier, Wayne; McConnell, Paul E.; Ghiaasiaan, M. (Georgia Institute of Technology, Atlanta, GA); Kern, Brian (Georgia Institute of Technology, Atlanta, GA); Tajima, Yu (University of California, Los Angeles, CA); Campen, Chistopher (University of California, Berkeley, CA); Sketchley, Tomas (University of California, Los Angeles, CA); Moir, R (Lawrence Livermore National Laboratories); Bardet, Philippe M. (University of California, Berkeley, CA); Durbin, Samuel; Morrow, Charles W.; Vigil, Virginia L (University of Wisconsin, Madison, WI); Modesto-Beato, Marcos A.; Franklin, James Kenneth; Smith, James Dean; Ying, Alice; Cook, Jason T.; Schmitz, Lothar (University of California, Los Angeles, CA); Abdel-Khalik, S. (Georgia Institute of Technology, Atlanta, GA); Farnum, Cathy Ottinger; Abdou, Mohamed A.; Bonazza, Riccardo; Rodriguez, Salvador B.; Sridharan, Kumar (University of Wisconsin, Madison, WI); Rochau, Gary Eugene; Gudmundson, Jesse; Peterson, Per F.; Marriott, Ed; Oakley, Jason

    2006-10-01

    This report summarizes the work conducted for the Z-inertial fusion energy (Z-IFE) late start Laboratory Directed Research Project. A major area of focus was on creating a roadmap to a z-pinch driven fusion power plant. The roadmap ties ZIFE into the Global Nuclear Energy Partnership (GNEP) initiative through the use of high energy fusion neutrons to burn the actinides of spent fuel waste. Transmutation presents a near term use for Z-IFE technology and will aid in paving the path to fusion energy. The work this year continued to develop the science and engineering needed to support the Z-IFE roadmap. This included plant system and driver cost estimates, recyclable transmission line studies, flibe characterization, reaction chamber design, and shock mitigation techniques.

  15. The theory of an auto-resonant field emission cathode relativistic electron accelerator for high efficiency microwave to direct current power conversion

    NASA Technical Reports Server (NTRS)

    Manning, Robert M.

    1990-01-01

    A novel method of microwave power conversion to direct current is discussed that relies on a modification of well known resonant linear relativistic electron accelerator techniques. An analysis is presented that shows how, by establishing a 'slow' electromagnetic field in a waveguide, electrons liberated from an array of field emission cathodes, are resonantly accelerated to several times their rest energy, thus establishing an electric current over a large potential difference. Such an approach is not limited to the relatively low frequencies that characterize the operation of rectennas, and can, with appropriate waveguide and slow wave structure design, be employed in the 300 to 600 GHz range where much smaller transmitting and receiving antennas are needed.

  16. Surface charge tunability as a powerful strategy to control electrostatic interaction for high efficiency silencing, using tailored oligopeptide-modified poly(beta-amino ester)s (PBAEs).

    PubMed

    Dosta, Pere; Segovia, Nathaly; Cascante, Anna; Ramos, Victor; Borrós, Salvador

    2015-07-01

    Here we present an extended family of pBAEs that incorporate terminal oligopeptide moieties synthesized from both positive and negative amino acids. Polymer formulations of mixtures of negative and positive oligopeptide-modified pBAEs are capable of condensing siRNA into discrete nanoparticles. We have demonstrated that efficient delivery of nucleic acids in a cell-type dependent manner can be achieved by careful control of the pBAE formulation. In addition, our approach of adding differently charged oligopeptides to the termini of poly(β-amino ester)s is of great interest for the design of tailored complexes having specific features, such as tuneable zeta potential. We anticipate that this surface charge tunability may be a powerful strategy to control unwanted electrostatic interactions, while preserving high silencing efficiency and reduced toxicity.

  17. High efficiency stationary hydrogen storage

    SciTech Connect

    Hynek, S.; Fuller, W.; Truslow, S.

    1995-09-01

    Stationary storage of hydrogen permits one to make hydrogen now and use it later. With stationary hydrogen storage, one can use excess electrical generation capacity to power an electrolyzer, and store the resultant hydrogen for later use or transshipment. One can also use stationary hydrogen as a buffer at fueling stations to accommodate non-steady fueling demand, thus permitting the hydrogen supply system (e.g., methane reformer or electrolyzer) to be sized to meet the average, rather than the peak, demand. We at ADL designed, built, and tested a stationary hydrogen storage device that thermally couples a high-temperature metal hydride to a phase change material (PCM). The PCM captures and stores the heat of the hydriding reaction as its own heat of fusion (that is, it melts), and subsequently returns that heat of fusion (by freezing) to facilitate the dehydriding reaction. A key component of this stationary hydrogen storage device is the metal hydride itself. We used nickel-coated magnesium powder (NCMP) - magnesium particles coated with a thin layer of nickel by means of chemical vapor deposition (CVD). Magnesium hydride can store a higher weight fraction of hydrogen than any other practical metal hydride, and it is less expensive than any other metal hydride. We designed and constructed an experimental NCM/PCM reactor out of 310 stainless steel in the form of a shell-and-tube heat exchanger, with the tube side packed with NCMP and the shell side filled with a eutectic mixture of NaCL, KCl, and MgCl{sub 2}. Our experimental results indicate that with proper attention to limiting thermal losses, our overall efficiency will exceed 90% (DOE goal: >75%) and our overall system cost will be only 33% (DOE goal: <50%) of the value of the delivered hydrogen. It appears that NCMP can be used to purify hydrogen streams and store hydrogen at the same time. These prospects make the NCMP/PCM reactor an attractive component in a reformer-based hydrogen fueling station.

  18. Summary of the 1st International Workshop on Environmental, Safety and Economic Aspects of Fusion Power

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Stevens, E.; Kim, K.; Maisonnier, D.; Kalashnikov, A.; Tobita, K.; Jackson, D.; Alejaldre, C.; Perrault, D.; Panayotov, D.; Merrill, B.; Grisolia, C.; Zucchetti, M.; Pinna, T.; van Houtte, D.; Konishi, S.; Kolbasov, B.

    2016-12-01

    The 1st International workshop on Environmental, Safety and Economic Aspects of Fusion Power (ESEFP) was held on 13 September 2015 at Jeju Island, South Korea. The workshop was initiated by the International Energy Agency Implementing Agreement on a Co-operative Program on ESEFP. The workshop was well attended with about forty participants representing twelve institutions in ten countries. The presentations covered safety issues and environmental impacts, availability improvement and risk control and socio-economic aspects of fusion power. Safety and licensing gaps between DEMO and ITER were discussed in depth with the consensus output presented as a plenary presentation at the 12th International Symposium on Fusion Nuclear Technology (ISFNT-12). The next workshop is planned to be held in conjunction with the ISFNT-13 in 2017.

  19. Commercial power from inertial confinement fusion: issues and prospects

    SciTech Connect

    Hogan, W.

    1985-05-01

    Future criteria for desirable power plants are difficult to determine, but they include economic competitiveness, availability of consumables, reliability, maintainability, safety, disposal of wastes, and environment impact. In the near future, the desirability of ICF power plants will probably be evaluated on terms similar to those used for fission reactors, which currently emphasize small, inherently safe reactors constructed from factory-built, standardized modules that can lower the direct capital costs and the construction time. Several of these issues are discussed.

  20. Requirements for high-efficiency solar cells

    NASA Technical Reports Server (NTRS)

    Sah, C. T.

    1986-01-01

    Minimum recombination and low injection level are essential for high efficiency. Twenty percent AM1 efficiency requires a dark recombination current density of 2 x 10 to the minus 13th power A/sq cm and a recombination center density of less than 10 to the 10th power /cu cm. Recombination mechanisms at thirteen locations in a conventional single crystalline silicon cell design are reviewed. Three additional recombination locations are described at grain boundaries in polycrystalline cells. Material perfection and fabrication process optimization requirements for high efficiency are outlined. Innovative device designs to reduce recombination in the bulk and interfaces of single crystalline cells and in the grain boundary of polycrystalline cells are reviewed.

  1. Discourse, Power, and Knowledge in the Management of "Big Science": The Production of Consensus in a Nuclear Fusion Research Laboratory.

    ERIC Educational Resources Information Center

    Kinsella, William J.

    1999-01-01

    Extends a Foucauldian view of power/knowledge to the archetypical knowledge-intensive organization, the scientific research laboratory. Describes the discursive production of power/knowledge at the "big science" laboratory conducting nuclear fusion research and illuminates a critical incident in which the fusion research…

  2. Development of D+3He Fusion Electric Thrusters and Power Supplies for Space

    NASA Astrophysics Data System (ADS)

    Morse, Thomas M.

    1994-07-01

    Development of D+3He Fusion Electric Thrusters (FET) and Power Supplies (FPS) should occur at a lunar base because of the following: availability of helium-3, a vacuum better than on Earth, low K in shade reachable by radiant cooling, supply of ``high temp'' superconducting ceramic-metals, and a low G environment. The early FET will be much smaller than an Apollo engine, with specific impulse of 10,000-100,000-s. Solar power and low G will aid early development. To counter the effect of low G on humans, centrifuges will be employed for sleeping and resting. Work will be done by telerobotic view control. The FPS will be of comparable size, and will generate power mainly by having replaceable rectennas, resonant to the fusion synchrotron radiation. FPSs are used for house keeping power and initiating superconduction. Spaceships will carry up to ten FETs and two FPSs. In addition to fusion fuel, the FET will inject H or Li low mass propellant into the fusion chamber. Developing an FET would be difficult on Earth. FET spaceships will park between missions in L1, and an FET Bus will fetch humans/supplies from Moon and Earth. Someday FETs, with rocket assist, will lift spaceships from Earth, and make space travel to planets far cheaper, faster, and safer, than at present. Too long a delay due to the space station, or the huge cost of getting into space by current means, will damage the morale of the space program.

  3. A flexible data fusion architecture for persistent surveillance using ultra-low-power wireless sensor networks

    NASA Astrophysics Data System (ADS)

    Hanson, Jeffrey A.; McLaughlin, Keith L.; Sereno, Thomas J.

    2011-06-01

    We have developed a flexible, target-driven, multi-modal, physics-based fusion architecture that efficiently searches sensor detections for targets and rejects clutter while controlling the combinatoric problems that commonly arise in datadriven fusion systems. The informational constraints imposed by long lifetime requirements make systems vulnerable to false alarms. We demonstrate that our data fusion system significantly reduces false alarms while maintaining high sensitivity to threats. In addition, mission goals can vary substantially in terms of targets-of-interest, required characterization, acceptable latency, and false alarm rates. Our fusion architecture provides the flexibility to match these trade-offs with mission requirements unlike many conventional systems that require significant modifications for each new mission. We illustrate our data fusion performance with case studies that span many of the potential mission scenarios including border surveillance, base security, and infrastructure protection. In these studies, we deployed multi-modal sensor nodes - including geophones, magnetometers, accelerometers and PIR sensors - with low-power processing algorithms and low-bandwidth wireless mesh networking to create networks capable of multi-year operation. The results show our data fusion architecture maintains high sensitivities while suppressing most false alarms for a variety of environments and targets.

  4. Sustaining neutral beam power supply system for the Mirror Fusion Test Facility

    SciTech Connect

    Eckard, R.D.; Wilson, J.H.; Van Ness, H.W.

    1980-01-01

    In late August 1978, a fixed price procurement contract for $25,000,000 was awarded to Aydin Energy Division, Palo Alto, California, for the design, manufacture, installation and acceptance testing of the Lawrence Livermore National Laboratory Mirror Fusion Test Facility (MFTF) Sustaining Neutral Beam Power Supply System (SNBPSS). This system of 24 power supply sets will provide the conditioned power for the 24 neutral beam source modules. Each set will provide the accel potential the arc power, the filament power, and the suppressor power for its associated neutral beam source module. The design and development of the SNBPSS has progressed through the final design phase and is now in production. Testing of the major sub-assembly power supply is proceeding at Aydin and the final acceptance testing of the first two power supplies at LLNL is expected to be completed this year.

  5. High efficiency solar cell processing

    NASA Technical Reports Server (NTRS)

    Ho, F.; Iles, P. A.

    1985-01-01

    At the time of writing, cells made by several groups are approaching 19% efficiency. General aspects of the processing required for such cells are discussed. Most processing used for high efficiency cells is derived from space-cell or concentrator cell technology, and recent advances have been obtained from improved techniques rather than from better understanding of the limiting mechanisms. Theory and modeling are fairly well developed, and adequate to guide further asymptotic increases in performance of near conventional cells. There are several competitive cell designs with promise of higher performance ( 20%) but for these designs further improvements are required. The available cell processing technology to fabricate high efficiency cells is examined.

  6. STARFIRE: a commercial tokamak fusion power plant study

    SciTech Connect

    Not Available

    1980-09-01

    This volume contains chapters on each of the following topics: (1) radioactivity, (2) heat transport and energy conversion, (3) tritium systems, (4) electrical storage and power supplies, (5) support structure, (6) cryogenics, (7) instrumentation and control, (8) maintenance and operation, (9) balance of plant design, (10) safety and environmental analysis, (11) economic analysis, and (12) plant construction.

  7. Tate Medal for International Leadership in Physics Talk: Nuclear Fusion Power: Are we really serious about our future?

    NASA Astrophysics Data System (ADS)

    Voss, Gustav-Adolf

    2010-02-01

    There's a frantic search under way for new energy sources that do not damage global climate. In the public discussion of this subject, nuclear fusion is hardly ever mentioned. Yet nuclear fusion is the answer to the problem. It's the best way to generate large amounts of baseload power, needed in the intermediate and far future. The long-standing joke about fusion always being ``just 50 years away'' illustrates the unfavourable attitude most people have towards fusion technology, and while this is understandable in the light of fusion's history, it is unwarranted. We need a strong international effort to develop this energy source to help avoid climate change turning into global disaster. )

  8. A partial coupling power of single mode fiber fusion

    NASA Astrophysics Data System (ADS)

    Saktioto, Toto; Ali, Jalil; Rahman, Rosly Abdul; Fadhali, Mohammed; Zainal, Jasman

    2008-01-01

    Coupled fibers are successfully fabricated by injecting hydrogen flow at 1bar and fused slightly by unstable torch flame in the range of 800-1350°C. Optical parameters may vary significantly over wide range physical properties. Coupling coefficient and refractive index are estimated from the experimental result of the coupling ratio distribution from 1% to 75%. The change of structural and geometrical fiber affects the normalized frequency (V) even for single mode fibers. Coupling ratio as a function of coupling coefficient and separation of fiber axis changes with respect to V at coupling region. V is derived from radius, wavelength and refractive index parameters. Parametric variations are performed on the left and right hand side of the coupling region. At the center of the coupling region V is assumed constant. A partial power is modeled and derived using V, normalized lateral phase constant (u), and normalized lateral attenuation constant, (w) through the second kind of modified Bessel function of the l order, which obeys the normal mode, LP 01 and normalized propagation constant (b). Total power is maintained constant in order to comply with the energy conservation law. The power is integrated through V, u and w over the pulling length range of 7500-9500 μm for 1-D where radial and angle directions are ignored. The core radius of fiber significantly affects V and power partially at coupling region rather than wavelength and refractive index of core and cladding. This model has power phenomena in transmission and reflection for industrial application of coupled fibers.

  9. Development of intermetallic coatings for fusion power applications

    SciTech Connect

    Park, J.H.; Domenico, T.; Dragel, G.; Clark, R.

    1994-03-01

    In the design of liquid-metal cooling systems, corrosion resistance of structural materials and magnetohydrodynamic (MHD) force and its subsequent influence on thermal hydraulics and corrosion are major concerns. The objective of this study is to develop stable corrosion-resistant electrical insulator coatings at the liquid-metal/structural-material interface, with emphasis on electrically insulating coatings that prevent adverse MHD-generated currents from passing through the structural walls. Vanadium and V-base alloys are potential materials for structural applications in a fusion reactor. Insulator coatings inside the tubing are required when the system is cooled by liquid metals. Various intermetallic films were produced on V, V-t, and V-20 Ti, V-5Cr-t and V-15Cr-t, and Ti, and Types 304 and 316 stainless steel. The intermetallic layers were developed by exposure of the materials to liquid lithium of 3--5 at.% and containing dissolved metallic solutes at temperatures of 416--880{degrees}C. Subsequently, electrical insulator coatings were produced by reaction of the reactive layers with dissolved nitrogen in liquid lithium or by air oxidation under controlled conditions at 600--1000{degrees}C. These reactions converted the intermetallic layers to electrically insulating oxide/nitride or oxy-nitride layers. This coating method could be applied to a commercial product. The liquid metal can be used over and over because only the solutes are consumed within the liquid metal. The technique can be applied to various shapes because the coating is formed by liquid-phase reaction. This paper will discuss initial results on the nature of the coatings and their in-situ electrical resistivity characteristics in liquid lithium at high temperatures.

  10. Cosmic Evolution of Accretion Power and Fusion Power: AGN and Starbursts at High Redshifts

    NASA Astrophysics Data System (ADS)

    Arnold Malkan, Matthew

    2009-05-01

    Extragalactic astronomers have been working for decades on obtaining robust measures of the luminosities galaxies produce from stars, and from active galactic nuclei. Our ultimate goal is deriving the cosmic evolution of all radiation produced by fusion and by black hole accretion. The combined effects of dust reddening and redshift make it impossible to achieve this with optical observations alone. Fortunately, infrared thermal continuum and forbidden line emission--from warm dust grains and ionized gas, respectively--can now be measured with excellent sensitivity. However, when measuring entire galaxies, these dust and gas emissions are powered by both active galactic nuclei and starbursts, which may be hard to separate spatially. We must use the fact that the patterns of IR energy output from AGN and SBs differ, with AGN making more ionized gas and hotter dust grains. Low-resolution spectroscopy, or even narrow-band filters can sort out the line emission from both processes when they are mixed in the same galaxy. The hope is that these spectroscopic determinations of star formation rate, and mass accretion rate in relatively small samples of bright galaxies will allow a calibration of broadband continuum measures. The dust continuum emission will then be measured in enormous samples of galaxies spanning their full range of masses, metallicities, environments and redshifts. Along the way, we should learn the astrophysical basis of black hole/galaxy "co-evolution." I will summarize some of the first specific infrared steps of this ambitious agenda, taken with IRAS and ISO to 2MASS, Akari and Spitzer and other telescopes. Time permitting, some of the exciting upcoming observational prospects will be advertised.

  11. Computational modeling of pulsed-power-driven magnetized target fusion experiments

    SciTech Connect

    Sheehey, P.; Kirkpatrick, R.; Lindemuth, I.

    1995-08-01

    Direct magnetic drive using electrical pulsed power has been considered impractically slow for traditional inertial confinement implosion of fusion targets. However, if the target contains a preheated, magnetized plasma, magnetothermal insulation may allow the near-adiabatic compression of such a target to fusion conditions on a much slower time scale. 100-MJ-class explosive flux compression generators with implosion kinetic energies far beyond those available with conventional fusion drivers, are an inexpensive means to investigate such magnetized target fusion (MTF) systems. One means of obtaining the preheated and magnetized plasma required for an MTF system is the recently reported {open_quotes}MAGO{close_quotes} concept. MAGO is a unique, explosive-pulsed-power driven discharge in two cylindrical chambers joined by an annular nozzle. Joint Russian-American MAGO experiments have reported D-T neutron yields in excess of 10{sup 13} from this plasma preparation stage alone, without going on to the proposed separately driven NM implosion of the main plasma chamber. Two-dimensional MED computational modeling of MAGO discharges shows good agreement to experiment. The calculations suggest that after the observed neutron pulse, a diffuse Z-pinch plasma with temperature in excess of 100 eV is created, which may be suitable for subsequent MTF implosion, in a heavy liner magnetically driven by explosive pulsed power. Other MTF concepts, such as fiber-initiated Z-pinch target plasmas, are also being computationally and theoretically evaluated. The status of our modeling efforts will be reported.

  12. Inertial confinement fusion reaction chamber and power conversion system study

    SciTech Connect

    Maya, I.; Schultz, K.R.; Battaglia, J.M.; Buksa, J.J.; Creedson, R.L.; Erlandson, O.D.; Levine, H.E.; Roelant, D.F.; Sanchez, H.W.; Schrader, S.A.

    1984-09-01

    GA Technologies has developed a conceptual ICF reactor system based on the Cascade rotating-bed reaction chamber concept. Unique features of the system design include the use of low activation SiC in a reaction chamber constructed of box-shaped tiles held together in compression by prestressing tendons to the vacuum chamber. Circulating Li/sub 2/O granules serve as the tritium breeding and energy transport material, cascading down the sides of the reaction chamber to the power conversion system. The total tritium inventory of the system is 6 kg; tritium recovery is accomplished directly from the granules via the vacuum system. A system for centrifugal throw transport of the hot Li/sub 2/O granules from the reaction chamber to the power conversion system has been developed. A number of issues were evaluated during the course of this study. These include the response of first-layer granules to the intense microexplosion surface heat flux, cost effective fabrication of Li/sub 2/O granules, tritium inventory and recovery issues, the thermodynamics of solids-flow options, vacuum versus helium-medium heat transfer, and the tradeoffs of capital cost versus efficiency for alternate heat exchange and power conversion system option. The resultant design options appear to be economically competitive, safe, and environmentally attractive.

  13. The future of high efficiency solar cells

    NASA Technical Reports Server (NTRS)

    Fan, J. C. C.

    1984-01-01

    Research approaches to obtain solar cell modules with 1 sun efficiencies of 20-30 percent at air mass 1 are now well understood. Such high efficiency modules should become available in the near future. It can be expected that these modules will be extensively used in terrestrial power generation, space power generation, and consumer electronics. To achieve practical module efficiencies significantly above 30 percent, it will be necessary to employ concepts other than spectral splitting, such as spectral compression and broad band detection. A major breakthrough in these areas is not anticipated at this time.

  14. Inertial fusion energy power reactor fuel recovery system

    SciTech Connect

    Gentile, C. A.; Kozub, T.; Langish, S. W.; Ciebiera, L. P.; Nobile, A.; Wermer, J.; Sessions, K.

    2008-07-15

    A conceptual design is proposed to support the recovery of un-expended fuel, ash, and associated post-detonation products resident in plasma exhaust from a {approx}2 GWIFE direct drive power reactor. The design includes systems for the safe and efficient collection, processing, and purification of plasma exhaust fuel components. The system has been conceptually designed and sized such that tritium bred within blankets, lining the reactor target chamber, can also be collected, processed, and introduced into the fuel cycle. The system will nominally be sized to process {approx}2 kg of tritium per day and is designed to link directly to the target chamber vacuum pumping system. An effort to model the fuel recovery system (FRS) using the Aspen Plus engineering code has commenced. The system design supports processing effluent gases from the reactor directly from the exhaust of the vacuum pumping system or in batch mode, via a buffer vessel in the Receiving and Analysis System. Emphasis is on nuclear safety, reliability, and redundancy as to maximize availability. The primary goal of the fuel recovery system design is to economically recycle components of direct drive IFE fuel. The FRS design is presented as a facility sub-system in the context of supporting the larger goal of producing safe and economical IFE power. (authors)

  15. Ion Deflection for Final Optics In Laser Inertial Fusion Power Plants

    SciTech Connect

    Abbott, R P; Latkowski, J F

    2006-11-17

    Left unprotected, both transmissive and reflective final optics in a laser inertial fusion power plant would quickly fail from melting, pulsed thermal stresses, or degradation of optical properties as a result of ion implantation. One potential option for mitigating this threat is to magnetically deflect the ions such that they are directed into a robust energy dump. In this paper we detail integrated studies that have been carried out to asses the viability of this approach for protecting final optics.

  16. Ion Deflection for Final Optics in Laser Inertial Fusion Power Plants

    SciTech Connect

    Abbott, Ryan P.

    2005-12-01

    Left unprotected, both transmissive and reflective final optics in a laser-driven inertial fusion power plant would quickly fail from melting, pulsed thermal stress, or degradation of optical properties as a result of ion implantation. One potential option for mitigating this threat is to magnetically deflect the ions such that they are directed to a robust energy dump. In this paper we detail integrated studies that have been carried out to assess the viability of this approach for protecting final optics.

  17. Developmental validation of the PowerPlex(®) Fusion 6C System.

    PubMed

    Ensenberger, Martin G; Lenz, Kristy A; Matthies, Learden K; Hadinoto, Gregory M; Schienman, John E; Przech, Angela J; Morganti, Michael W; Renstrom, Daniel T; Baker, Victoria M; Gawrys, Kori M; Hoogendoorn, Marlijn; Steffen, Carolyn R; Martín, Pablo; Alonso, Antonio; Olson, Hope R; Sprecher, Cynthia J; Storts, Douglas R

    2016-03-01

    The PowerPlex(®) Fusion 6C System is a 27-locus, six-dye, multiplex that includes all markers in the expanded CODIS core loci and increases overlap with STR database standards throughout the world. Additionally, it contains two, rapidly mutating, Y-STRs and is capable of both casework and database workflows, including direct amplification. A multi-laboratory developmental validation study was performed on the PowerPlex(®) Fusion 6C System. Here, we report the results of that study which followed SWGDAM guidelines and includes data for: species specificity, sensitivity, stability, precision, reproducibility and repeatability, case-type samples, concordance, stutter, DNA mixtures, and PCR-based procedures. Where appropriate we report data from both extracted DNA samples and direct amplification samples from various substrates and collection devices. Samples from all studies were separated on both Applied Biosystems 3500 series and 6-dye capable 3130 series Genetic Analyzers and data is reported for each. Together, the data validate the design and demonstrate the performance of the PowerPlex(®) Fusion 6C System.

  18. High Efficiency Room Air Conditioner

    SciTech Connect

    Bansal, Pradeep

    2015-01-01

    This project was undertaken as a CRADA project between UT-Battelle and Geberal Electric Company and was funded by Department of Energy to design and develop of a high efficiency room air conditioner. A number of novel elements were investigated to improve the energy efficiency of a state-of-the-art WAC with base capacity of 10,000 BTU/h. One of the major modifications was made by downgrading its capacity from 10,000 BTU/hr to 8,000 BTU/hr by replacing the original compressor with a lower capacity (8,000 BTU/hr) but high efficiency compressor having an EER of 9.7 as compared with 9.3 of the original compressor. However, all heat exchangers from the original unit were retained to provide higher EER. The other subsequent major modifications included- (i) the AC fan motor was replaced by a brushless high efficiency ECM motor along with its fan housing, (ii) the capillary tube was replaced with a needle valve to better control the refrigerant flow and refrigerant set points, and (iii) the unit was tested with a drop-in environmentally friendly binary mixture of R32 (90% molar concentration)/R125 (10% molar concentration). The WAC was tested in the environmental chambers at ORNL as per the design rating conditions of AHAM/ASHRAE (Outdoor- 95F and 40%RH, Indoor- 80F, 51.5%RH). All these modifications resulted in enhancing the EER of the WAC by up to 25%.

  19. Interface modification for highly efficient organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Steim, Roland; Choulis, Stelios A.; Schilinsky, Pavel; Brabec, Christoph J.

    2008-03-01

    We present highly efficient inverted polymer:fullerene bulk-heterojunction solar cells by incorporation of a nanoscale organic interfacial layer between the indium tin oxide (ITO) and the metal oxide electron-conducting layer. We demonstrate that stacking of solution-processed organic and metal oxide interfacial layers gives highly charged selective low ohmic cathodes. The incorporation of a polyoxyethylene tridecyl ether interfacial layer between ITO and solution-processed titanium oxide (TiOx) raised the power conversion efficiency of inverted organic photovoltaics to 3.6%, an improvement of around 15% in their performance over comparable devices without the organic interfacial layer.

  20. Axisymmetric Tandem Mirror Magnetic Fusion Energy Power Plant with Thick Liquid-Walls

    SciTech Connect

    Moir, R W; Rognlien, T D

    2006-04-26

    A fusion power plant is described that utilizes a new version of the tandem mirror device including spinning liquid walls. The magnetic configuration is evaluated with an axisymmetric equilibrium code predicting an average beta of 60%. The geometry allows a flowing molten salt, (flibe-Li{sub 2}BeF{sub 4}), which protects the walls and structures from damage arising from neutrons and plasma particles. The free surface between the liquid and the burning plasma is heated by bremsstrahlung radiation, line radiation, and by neutrons. The temperature of the free surface of the liquid is calculated, and then the evaporation rate is estimated from vapor-pressure data. The allowed impurity concentration in the burning plasma is taken as 1% fluorine, which gives a 17% reduction in the fusion power owing to D/T fuel dilution, with F line-radiation causing minor power degradation. The end leakage power density of 0.6 MW/m{sup 2} is readily handled by liquid jets. The tritium breeding is adequate with natural lithium. A number of problem areas are identified that need further study to make the design more self-consistent and workable; however, the simple geometry and the use of liquid walls promise the cost of power competitive with that from fission and coal.

  1. DT fusion power production in ELM free H modes in JET

    NASA Astrophysics Data System (ADS)

    Rimini, F. G.; JET Team

    1999-11-01

    Experiments in the ELM free hot ion H mode regime have been carried out in DT plasmas in JET. Initial experiments undertaken at constant neutral beam (NB) power (~11 MW) demonstrated that core fuelling was dominated by wall/target recycling rather than NB fuelling and made it possible to arrange an optimum core DT mix by adjusting the DT mix in wall/target, gas and NB. High power experiments at 4.2 MA/3.6 T have successfully and reliably delivered fusion power (Pfus) up to 16.1 MW and plasma stored energy (Wdia) up to 17 MJ. The results are in good agreement with extrapolations, carried out with the TRANSP and JETTO codes, from similar deuterium discharges. Transiently, values of Qtot up to 0.95 +/-0.17 were achieved, consistent with values of nDT(0)τE, diaTi (0) approx 8.7 × 1020 m-3·s·keV+/-20%. The ratio of fusion power to input power, Qin, is in excess of 0.6. There are indications of an isotope effect on the edge pressure pedestal, but no net dependence of global confinement on isotopic plasma composition has been found.

  2. Accident consequences analysis of the HYLIFE-II inertial fusion energy power plant design

    SciTech Connect

    Reyes, S; Gomez del Rio, J; Sanz, J

    2000-02-23

    Previous studies of the safety and environmental (S and E) aspects of the HYLIFE-II inertial fusion energy (IFE) power plant design have used simplistic assumptions in order to estimate radioactivity releases under accident conditions. Conservatisms associated with these traditional analyses can mask the actual behavior of the plant and have revealed the need for more accurate modeling and analysis of accident conditions and radioactivity mobilization mechanisms. In the present work a set of computer codes traditionally used for magnetic fusion safety analyses (CHEMCON, MELCOR) has been applied for simulating accident conditions in a simple model of the HYLIFE-II IFE design. Here the authors consider a severe lost of coolant accident (LOCA) producing simultaneous failures of the beam tubes (providing a pathway for radioactivity release from the vacuum vessel towards the containment) and of the two barriers surrounding the chamber (inner shielding and containment building it self). Even though containment failure would be a very unlikely event it would be needed in order to produce significant off-site doses. CHEMCON code allows calculation of long-term temperature transients in fusion reactor first wall, blanket, and shield structures resulting from decay heating. MELCOR is used to simulate a wide range of physical phenomena including thermal-hydraulics, heat transfer, aerosol physics and fusion product release and transport. The results of these calculations show that the estimated off-site dose is less than 6 mSv (0.6 rem), which is well below the value of 10 mSv (1 rem) given by the DOE Fusion Safety Standards for protection of the public from exposure to radiation during off-normal conditions.

  3. Highly efficient pulsed power supply system with a two-stage LC generator and a step-up transformer for fast capillary discharge soft x-ray laser at shorter wavelength.

    PubMed

    Sakai, Yusuke; Takahashi, Shnsuke; Komatsu, Takanori; Song, Inho; Watanabe, Masato; Hotta, Eiki

    2010-01-01

    Highly efficient and compact pulsed power supply system for a capillary discharge soft x-ray laser (SXRL) has been developed. The system consists of a 2.2 microF two-stage LC inversion generator, a 2:54 step-up transformer, a 3 nF water capacitor, and a discharge section with a few tens of centimeter length capillary. Adoption of the pulsed transformer in combination with the LC inversion generator enables us to use only one gap switch in the circuit for charging the water capacitor up to about 0.5 MV. Furthermore, step-up ratio of a water capacitor voltage to a LC inversion generator initial charging voltage is about 40 with energy transfer efficiency of about 50%. It also leads to good reproducibility of a capillary discharge which is necessary for lasing a SXRL stably. For the study of the possibility of lasing a SXRL at shorter wavelength in a small laboratory scale, high-density and high-temperature plasma column suitable for the laser can be generated relatively easily with this system.

  4. Highly efficient pulsed power supply system with a two-stage LC generator and a step-up transformer for fast capillary discharge soft x-ray laser at shorter wavelength

    SciTech Connect

    Sakai, Yusuke; Takahashi, Shnsuke; Komatsu, Takanori; Song, Inho; Watanabe, Masato; Hotta, Eiki

    2010-01-15

    Highly efficient and compact pulsed power supply system for a capillary discharge soft x-ray laser (SXRL) has been developed. The system consists of a 2.2 {mu}F two-stage LC inversion generator, a 2:54 step-up transformer, a 3 nF water capacitor, and a discharge section with a few tens of centimeter length capillary. Adoption of the pulsed transformer in combination with the LC inversion generator enables us to use only one gap switch in the circuit for charging the water capacitor up to about 0.5 MV. Furthermore, step-up ratio of a water capacitor voltage to a LC inversion generator initial charging voltage is about 40 with energy transfer efficiency of about 50%. It also leads to good reproducibility of a capillary discharge which is necessary for lasing a SXRL stably. For the study of the possibility of lasing a SXRL at shorter wavelength in a small laboratory scale, high-density and high-temperature plasma column suitable for the laser can be generated relatively easily with this system.

  5. Progress in accident analysis of the HYLIFE-II inertial fusion energy power plant design

    SciTech Connect

    Reyes, S; Latkowski, J F; Gomez del Rio, J; Sanz, J

    2000-10-11

    The present work continues our effort to perform an integrated safety analysis for the HYLIFE-II inertial fusion energy (IFE) power plant design. Recently we developed a base case for a severe accident scenario in order to calculate accident doses for HYLIFE-II. It consisted of a total loss of coolant accident (LOCA) in which all the liquid flibe (Li{sub 2}BeF{sub 4}) was lost at the beginning of the accident. Results showed that the off-site dose was below the limit given by the DOE Fusion Safety Standards for public protection in case of accident, and that his dose was dominated by the tritium released during the accident.

  6. High efficiency laser spectrum conditioner

    DOEpatents

    Greiner, Norman R.

    1980-01-01

    A high efficiency laser spectrum conditioner for generating a collinear parallel output beam containing a predetermined set of frequencies from a multifrequency laser. A diffraction grating and spherical mirror are used in combination, to disperse the various frequencies of the input laser beam and direct these frequencies along various parallel lines spatially separated from one another to an apertured mask. Selection of the desired frequencies is accomplished by placement of apertures at locations on the mask where the desired frequencies intersect the mask. A recollimated parallel output beam with the desired set of frequencies is subsequently generated utilizing a mirror and grating matched and geometrically aligned in the same manner as the input grating and mirror.

  7. High Efficiency IMM Solar Cells

    NASA Astrophysics Data System (ADS)

    Sharps, P.; Cho, B.; Chumney, D.; Cornfeild, A.; Guzie, B.; Hazlett, D.; Lin, Y.; Mackos, C.; Patel, P.; Stan, M.; Steinfeldt, J.; Tourino, C.

    2014-08-01

    We review the status of currently available commercial multi-junction cells, review options for next generation high efficiency cell architectures, and present the latest developments on the inverted metamorphic multi- junction (IMM) solar cell. Over 20,000 IMM cells have been prototyped to date, and efficiencies of up to 37% have been measured. We present the most recent performance data, including the response to particle radiation. The IMM cell can be used in a number of rigid or flexible configurations, and considerable effort is currently focused on cell packaging and panel integration. We discuss several design options, including a "drop in" replacement for the current 29.5% ZTJ cell technology. We will also address the reliability and cost of the IMM cell.

  8. The High-Yield Lithium-Injection Fusion-Energy (HYLIFE)-II inertial fusion energy (IFE) power plant concept and implications for IFE

    NASA Astrophysics Data System (ADS)

    Moir, Ralph W.

    1995-06-01

    In the High-Yield Lithium-Injection Fusion-Energy (HYLIFE) power plant design, lithium is replaced by molten salt. HYLIFE-II [Fusion Technol. 25, 5 (1994)] is based on nonflammable, renewable-liquid-wall fusion target chambers formed with Li2BeF4 molten-salt jets, a heavy-ion driver, and single-sided illumination of indirect-drive targets. Building fusion chambers from existing materials with life-of-plant structural walls behind the liquid walls, while still meeting non-nuclear grade construction and low-level waste requirements, has profound implications for inertial fusion energy (IFE) development. Fluid-flow work and computational fluid dynamics predict chamber clearing adequate for 6 Hz pulse rates. Predicted electricity cost is reduced about 30% to 4.4¢/kWh at 1 GWe and 3.2¢/kWh at 2 GWe. Development can be foreshortened and cost reduced by obviating expensive neutron sources to develop first-wall materials. The driver and chamber can be upgraded in stages, avoiding separate and sequential facilities. Important features of a practical IFE power plant are ignition and sufficient gain in targets; low-cost, efficient, rep-ratable driver; and low-cost targets.

  9. High-efficiency silicon concentrator cell commercialization

    SciTech Connect

    Sinton, R.A.; Swanson, R.M.

    1993-05-01

    This report summarizes the first phase of a forty-one month program to develop a commercial, high-efficiency concentrator solar cell and facility for manufacturing it. The period covered is November 1, 1990 to December 31, 1991. This is a joint program between the Electric Power Research Institute (EPRI) and Sandia National Laboratories. (This report is also published by EPRI as EPRI report number TR-102035.) During the first year of the program, SunPower accomplished the following major objectives: (1) a new solar cell fabrication facility, which is called the Cell Pilot Line (CPL), (2) a baseline concentrator cell process has been developed, and (3) a cell testing facility has been completed. Initial cell efficiencies are about 23% for the baseline process. The long-range goal is to improve this efficiency to 27%.

  10. High-power microwave transmission and launching systems for fusion plasma heating systems

    SciTech Connect

    Bigelow, T.S.

    1989-01-01

    Microwave power in the 30- to 300-GHz frequency range is becoming widely used for heating of plasma in present-day fusion energy magnetic confinement experiments. Microwave power is effective in ionizing plasma and heating electrons through the electron cyclotron heating (ECH) process. Since the power is absorbed in regions of the magnetic field where resonance occurs and launching antennas with narrow beam widths are possible, power deposition location can be highly controlled. This is important for maximizing the power utilization efficiency and improving plasma parameters. Development of the gyrotron oscillator tube has advanced in recent years so that a 1-MW continuous-wave, 140-GHz power source will soon be available. Gyrotron output power is typically in a circular waveguide propagating a circular electric mode (such as TE/sub 0,2/) or a whispering-gallery mode (such as TE/sub 15,2/), depending on frequency and power level. An alternative high-power microwave source currently under development is the free-electron laser (FEL), which may be capable of generating 2-10 MW of average power at frequencies of up to 500 GHz. The FEL has a rectangular output waveguide carrying the TE/sub 0,1/ mode. Because of its higher complexity and cost, the high-average-power FEL is not yet as extensively developed as the gyrotron. In this paper, several types of operating ECH transmission systems are discussed, as well systems currently being developed. The trend in this area is toward higher power and frequency due to the improvements in plasma density and temperature possible. Every system requires a variety of components, such as mode converters, waveguide bends, launchers, and directional couplers. Some of these components are discussed here, along with ongoing work to improve their performance. 8 refs.

  11. Next generation laser optics for a hybrid fusion-fission power plant

    SciTech Connect

    Stolz, C J; Latkowski, J T; Schaffers, K I

    2009-09-10

    The successful completion of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL), followed by a campaign to achieve ignition, creates the proper conditions to begin exploring what development work remains to construct a power plant based on Inertial Confinement Fusion (ICF) technology. Fundamentally, two distinct NIF laser properties must be overcome. The repetition rate must increase from a shot every four hours to several shots per second. Additionally, the efficiency of converting electricity to laser light must increase by 20x to roughly 10 percent. Solid state diode pumped lasers, commercially available for table top applications, have adequate repetition rates and power conversion efficiencies, however, they operate at a tiny fraction of the required energy for an ICF power plant so would need to be scaled in energy and aperture. This paper describes the optics and coatings that would be needed to support this type of laser architecture.

  12. Transport vehicle for manned Mars missions powered by inertial confinement fusion

    SciTech Connect

    Orth, C.D.; Klein, G.; Sercel, J.; Hoffman, N.; Murray, K.; Chang-Diaz, F.

    1987-06-26

    Inertial confinement fusion (ICF) is an ideal engine power source for manned spacecraft to Mars because of its inherently high power-to-mass ratios and high specific impulses. We have produced a concept for a vehicle powered by ICF and utilizing a magnetic thrust chamber to avoid plasma thermalization with wall structures and the resultant degradation of specific impulse that are unavoidable with the use of mechanical thrust chambers. This vehicle is capable of 100-day manned Mars missions with a 100-metric-ton payload and a total vehicle launch mass near 6000 metric tons, based on advanced technology assumed to be available by A.D. 2020. Such short-duration missions minimize radiation exposures and physiological deterioration of astronauts.

  13. The HYLIFE-2 inertial fusion energy power plant concept and implications for IFE

    NASA Astrophysics Data System (ADS)

    Moir, Ralph W.

    1994-11-01

    HYLIFE-II is based on nonflammable, renewable-liquid-wall fusion target chambers formed with Li2BeF4 molten-salt jets, a heavy-ion driver, and single-sided illumination of indirect-drive targets. Building fusion chambers from existing materials with life-of-plant structural walls behind the liquid walls, while still meeting non-nuclear grade construction and low-level waste requirements, has profound implications for IFE development. Fluid-flow work and computational fluid dynamics predict chamber clearing adequate for 6-Hz pulse rates. Predicted electricity cost is reduced about 30% to 4.4 cents/kWh at 1 GWe. Development can be foreshortened and cost reduced by obviating expensive neutron sources to develop first-wall materials. The driver and chamber can be upgraded in stages, avoiding separate and sequential facilities. The most important features of a practical inertial fusion power plant are sufficient ignition and gain in targets; a low-cost, efficient, rep-ratable driver; and low-cost targets.

  14. Electricity production from laser-driven fusion reactors: technological aspects of power conversion chambers

    NASA Astrophysics Data System (ADS)

    Kulcinski, Gerald L.

    2000-01-01

    One of the most important considerations for laser driven fusion power plants is the safe and efficient operation of the chamber that contains the thermonuclear energy released from the target. Several approaches to the design of such a chamber are described in this paper and the critical issues associated with protection of the first wall, the performance of the structural materials, and the cost are discussed. Presently, the need for direct drive illumination of the cryogenic targets makes the use of liquid first wall protection problematical at best. The use of dry first walls protected with a few torr of an inert gas seems to hold the most promise.

  15. High-efficiency photovoltaic cells

    DOEpatents

    Yang, H.T.; Zehr, S.W.

    1982-06-21

    High efficiency solar converters comprised of a two cell, non-lattice matched, monolithic stacked semiconductor configuration using optimum pairs of cells having bandgaps in the range 1.6 to 1.7 eV and 0.95 to 1.1 eV, and a method of fabrication thereof, are disclosed. The high band gap subcells are fabricated using metal organic chemical vapor deposition (MOCVD), liquid phase epitaxy (LPE) or molecular beam epitaxy (MBE) to produce the required AlGaAs layers of optimized composition, thickness and doping to produce high performance, heteroface homojunction devices. The low bandgap subcells are similarly fabricated from AlGa(As)Sb compositions by LPE, MBE or MOCVD. These subcells are then coupled to form a monolithic structure by an appropriate bonding technique which also forms the required transparent intercell ohmic contact (IOC) between the two subcells. Improved ohmic contacts to the high bandgap semiconductor structure can be formed by vacuum evaporating to suitable metal or semiconductor materials which react during laser annealing to form a low bandgap semiconductor which provides a low contact resistance structure.

  16. High efficiency shale oil recovery

    SciTech Connect

    Adams, C.D.

    1992-07-18

    The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated at bench-scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although an oil shale batch sample is sealed in the batch kiln from the start until the end of the run, the process conditions for the batch are the same as the conditions that an element of oil shale would encounter in a larger continuous process kiln. For example, similar conditions of heatup rate, oxidation of the residue and cool-down prevail for the element in both systems. This batch kiln is a unit constructed in a 1987 Phase I SBIR tar sand retorting project. The kiln worked fairly well in that project; however, the need for certain modifications was observed. These modifications are now underway to simplify the operation and make the data and analysis more exact. The second quarter agenda consisted of (a) kiln modifications; (b) sample preparation; and (c) Heat Transfer calibration runs (part of proposal task number 3 -- to be completed by the end of month 7).

  17. Osiris and SOMBRERO inertial confinement fusion power plant designs. Volume 1, Executive summary and overview, Final report

    SciTech Connect

    Meier, W.R.; Bieri, R.L.; Monsler, M.J.

    1992-03-01

    Conceptual designs and assessments have been completed for two inertial fusion energy (IFE) electric power plants. The detailed designs and results of the assessment studies are presented in this report. Osiris is a heavy-ion-beam (HIB) driven power plant and SOMBRERO is a Krypton-Fluoride (KrF) laser-driven power plant. Both plants are sized for a net electric power of 1000 MWe.

  18. Development of effective power supply using electric double layer capacitor for static magnetic field coils in fusion plasma experiments.

    PubMed

    Inomoto, M; Abe, K; Yamada, T; Kuwahata, A; Kamio, S; Cao, Q H; Sakumura, M; Suzuki, N; Watanabe, T; Ono, Y

    2011-02-01

    A cost-effective power supply for static magnetic field coils used in fusion plasma experiments has been developed by application of an electric double layer capacitor (EDLC). A prototype EDLC power supply system was constructed in the form of a series LCR circuit. Coil current of 100 A with flat-top longer than 1 s was successfully supplied to an equilibrium field coil of a fusion plasma experimental apparatus by a single EDLC module with capacitance of 30 F. The present EDLC power supply has revealed sufficient performance for plasma confinement experiments whose discharge duration times are an order of several seconds.

  19. High efficiency shale oil recovery

    SciTech Connect

    Adams, D.C.

    1992-01-01

    The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated at bench-scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although a batch oil shale sample will be sealed in the batch kiln from the start until the end of the run, the process conditions for the batch will be the same as the conditions that an element of oil shale would encounter in a large continuous process kiln. For example, similar conditions of heat-up rate (20 deg F/min during the pyrolysis), oxidation of the residue and cool-down will prevail for the element in both systems. This batch kiln is a unit constructed in a 1987 Phase I SBIR tar sand retorting project. The kiln worked fairly well in that project; however, the need for certain modifications was observed. These modifications are now underway to simplify the operation and make the data and analysis more exact. The agenda for the first three months of the project consisted of the first of nine tasks and was specified as the following four items: 1. Sample acquisition and equipment alteration: Obtain seven oil shale samples, of varying grade each 10 lb or more, and samples of quartz sand. Order equipment for kiln modification. 3. Set up and modify kiln for operation, including electric heaters on the ends of the kiln. 4. Connect data logger and make other repairs and changes in rotary batch kiln.

  20. High efficiency shale oil recovery

    SciTech Connect

    Adams, D.C.

    1993-04-22

    The overall project objective is to demonstrate the high efficiency of the Adams Counter-Current shale oil recovery process. The efficiency will first be demonstrated on a small scale, in the current phase, after which the demonstration will be extended to the operation of a small pilot plant. Thus the immediate project objective is to obtain data on oil shale retorting operations in a small batch rotary kiln that will be representative of operations in the proposed continuous process pilot plant. Although an oil shale batch sample is sealed in the batch kiln from the start until the end of the run, the process conditions for the batch are the same as the conditions that an element of oil shale would encounter in a continuous process kiln. Similar chemical and physical conditions (heating, mixing, pyrolysis, oxidation) exist in both systems.The two most important data objectives in this phase of the project are to demonstrate (1) that the heat recovery projected for this project is reasonable and (2) that an oil shale kiln will run well and not plug up due to sticking and agglomeration. The following was completed this quarter. (1) Twelve pyrolysis runs were made on five different oil shales. All of the runs exhibited a complete absence of any plugging, tendency. Heat transfer for Green River oil shale in the rotary kiln was 84.6 Btu/hr/ft[sup 2]/[degrees]F, and this will provide for ample heat exchange in the Adams kiln. (2) One retorted residue sample was oxidized at 1000[degrees]F. Preliminary indications are that the ash of this run appears to have been completely oxidized. (3) Further minor equipment repairs and improvements were required during the course of the several runs.

  1. Scaling magnetized liner inertial fusion on Z and future pulsed-power accelerators

    NASA Astrophysics Data System (ADS)

    Slutz, S. A.; Stygar, W. A.; Gomez, M. R.; Peterson, K. J.; Sefkow, A. B.; Sinars, D. B.; Vesey, R. A.; Campbell, E. M.; Betti, R.

    2016-02-01

    The MagLIF (Magnetized Liner Inertial Fusion) concept [S. A. Slutz et al., Phys. Plasmas 17, 056303 (2010)] has demonstrated fusion-relevant plasma conditions [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] on the Z accelerator with a peak drive current of about 18 MA. We present 2D numerical simulations of the scaling of MagLIF on Z as a function of drive current, preheat energy, and applied magnetic field. The results indicate that deuterium-tritium (DT) fusion yields greater than 100 kJ could be possible on Z when all of these parameters are at the optimum values: i.e., peak current = 25 MA, deposited preheat energy = 5 kJ, and Bz = 30 T. Much higher yields have been predicted [S. A. Slutz and R. A. Vesey, Phys. Rev. Lett. 108, 025003 (2012)] for MagLIF driven with larger peak currents. Two high performance pulsed-power accelerators (Z300 and Z800) based on linear-transformer-driver technology have been designed [W. A. Stygar et al., Phys. Rev. ST Accel. Beams 18, 110401 (2015)]. The Z300 design would provide 48 MA to a MagLIF load, while Z800 would provide 65 MA. Parameterized Thevenin-equivalent circuits were used to drive a series of 1D and 2D numerical MagLIF simulations with currents ranging from what Z can deliver now to what could be achieved by these conceptual future pulsed-power accelerators. 2D simulations of simple MagLIF targets containing just gaseous DT have yields of 18 MJ for Z300 and 440 MJ for Z800. The 2D simulated yield for Z800 is increased to 7 GJ by adding a layer of frozen DT ice to the inside of the liner.

  2. Progress toward fusion with light ions

    SciTech Connect

    1980-01-01

    New results in target design, beam generation and transport, and pulse power technology have led to a program shift stressing light ion-driven inertial confinement fusion. According to present estimates, a gain ten fusion pellet will require at least one megajoule and approx. 100 TW power input. Progress in ion sources has resulted in beam power density of approx. 1 TW/cm/sup 2/, a factor of ten increase over the last year, and cylindrical implosion experiments have been performed. Other experiments have demonstrated the ability to transport ion and electron beams with high efficiency and have confirmed numerical predictions on the properties of beam transport channels converging at a target. These developments together with improvements in pulse power technology allow us to project that the 72 beam, 100 TW Particle Beam Fusion Accelerator, PBFA-II will attain target output energy equal to stored energy in the accelerator.

  3. Development of gyrotrons for fusion with power exceeding 1 MW over a wide frequency range

    NASA Astrophysics Data System (ADS)

    Kariya, T.; Imai, T.; Minami, R.; Numakura, T.; Eguchi, T.; Kato, T.; Endo, Y.; Ichimura, M.; Shimozuma, T.; Kubo, S.; Takahashi, H.; Yoshimura, Y.; Igami, H.; Ito, S.; Mutoh, T.; Sakamoto, K.; Idei, H.; Zushi, H.; Nagasaki, K.; Sano, F.; Ono, M.; Mitsunaka, Y.

    2015-09-01

    Megawatt-class gyrotrons covering a wide frequency range (14 GHz-300 GHz) are in increasing demand for nuclear fusion. Recent electron cyclotron heating and electron cyclotron current drive experiments highlight a requirement of megawatt-scale gyrotrons at a relatively lower frequency (14-35 GHz) range of some plasma devices, like GAMMA 10/PDX of the University of Tsukuba, QUEST of Kyushu University, NSTX-U of Princeton Plasma Physics Laboratory, and Heliotron J of Kyoto University. Collaborative studies for designing a new 28 GHz/35 GHz dual-frequency gyrotron and a 14 GHz gyrotron have commenced. Operation above 1 MW of 28 GHz/35 GHz dual oscillation was demonstrated experimentally. Further in the design of dual-frequency gyrotron, operations with 2 MW 3 s and 0.4 MW CW (continuous wave) at 28 GHz, and power exceeding 1 MW for 3 s at 34.8 GHz have been shown to be feasible. The 14 GHz gyrotron is expected to operate above 1 MW. We are also developing higher frequency gyrotrons (77-300 GHz). The joint program of National Institute for Fusion Science and the University of Tsukuba developed two new 154 GHz gyrotrons for the large helical device after the demonstration of three 77 GHz gyrotrons. The 154 GHz gyrotrons achieved a maximum output power of 1.25 MW and quasi-CW operation of 0.35 MW for 30 min.

  4. Final Focus Shielding Designs for Modern Heavy-Ion Fusion Power Plant Designs

    SciTech Connect

    Latkowski, J F; Meier, W R

    2000-07-05

    Recent work in heavy-ion fusion accelerators and final focusing systems shows a trend towards less current per beam, and thus, a greater number of beams. Final focusing magnets are susceptible to nuclear heating, radiation damage, and neutron activation. The trend towards more beams, however, means that there can be less shielding for each magnet, Excessive levels of nuclear heating may lead to magnet quench or an intolerable recirculating power for magnet cooling. High levels of radiation damage may result in short magnet lifetimes and low reliability. Finally, neutron activation of the magnet components may lead to difficulties in maintenance, recycling, and waste disposal. The present work expands upon previous, three-dimensional magnet shielding calculations for a modified version of the HYLIFE-I1 IFE power plant design. We present key magnet results as a function of the number of beams.

  5. Final focus shielding designs for modern heavy-ion fusion power plant designs

    NASA Astrophysics Data System (ADS)

    Latkowski, J. F.; Meier, W. R.

    2001-05-01

    Recent work in heavy-ion fusion accelerators and final focusing systems shows a trend towards less current per beam, and thus, a greater number of beams. Final focusing magnets are susceptible to nuclear heating, radiation damage, and neutron activation. The trend towards more beams, however, means that there can be less shielding for each magnet. Excessive levels of nuclear heating may lead to magnet quench or to an intolerable recirculating power for magnet cooling. High levels of radiation damage may result in short magnet lifetimes and low reliability. Finally, neutron activation of the magnet components may lead to difficulties in maintenance, recycling, and waste disposal. The present work expands upon previous, three-dimensional magnet shielding calculations for a modified version of the HYLIFE-II IFE power plant design. We present key magnet results as a function of the number of beams.

  6. Polarization Issues with High Power Injection and Low Power Emission in Fusion Experiments

    SciTech Connect

    Goodman, T. P.; Felici, F.; Udintsev, V. S.

    2009-11-26

    All tokamak experiments using ECCD require setting of the beam elliptical polarization for proper coupling to the plasma. This is done either in the matching optics unit (MOU) at the output of the gyrotron, or in a couple of miter bends of the transmission line. Similarly, oblique ECE receivers require selection of the correct elliptical polarization to provide localized measurements. For the TCV tokamak at the CRPP, gyrotron and oblique-ECE polarizers are characterized during either high- or low- power testing of equipment: for the gyrotrons the behaviour is determined at a single frequency, but for the oblique-ECE the broadband response is needed. These characteristics are included in the calibration database and used during subsequent analysis of the power coupling to, or from, the sources (gyrotron, plasma, or low power transmitting antenna). A more detailed characterization has been carried out (at low power) with the MOU for the EU, 170 GHz, 2 MW, gyrotron prototype for ITER. This paper discusses the methodology and results of these measurements, as well as a review of nearly a decade's worth of experimental data from the 6 gyrotron, 3 MW, 82.6 GHz TCV system. In particular, the consistency between the calibrations and the subsequent data from tokamak experiments is analysed.

  7. High Efficiency Cascade Solar Cells

    SciTech Connect

    Shuguang Deng, Seamus Curran, Igor Vasiliev

    2010-09-28

    This report summarizes the main work performed by New Mexico State University and University of Houston on a DOE sponsored project High Efficiency Cascade Solar Cells. The main tasks of this project include materials synthesis, characterization, theoretical calculations, organic solar cell device fabrication and test. The objective of this project is to develop organic nano-electronic-based photovoltaics. Carbon nanotubes and organic conjugated polymers were used to synthesize nanocomposites as the new active semiconductor materials that were used for fabricating two device architectures: thin film coating and cascade solar cell fiber. Chemical vapor deposition technique was employed to synthesized a variety of carbon nanotubes (single-walled CNT, doubled-walled CNT, multi-walled CNT, N-doped SWCNT, DWCNT and MWCNT, and B-doped SWCNT, DWCNT and MWCNT) and a few novel carbon structures (CNT-based nanolance, nanocross and supported graphene film) that have potential applications in organic solar cells. Purification procedures were developed for removing amorphous carbons from carbon nanotubes, and a controlled oxidation method was established for partial truncation of fullerene molecules. Carbon nanotubes (DWCNT and DWCNT) were functionalized with fullerenes and dyes covalently and used to form nanocomposites with conjugated polymers. Biologically synthesized Tellurium nanotubes were used to form composite with the conjugated polymers as well, which generated the highest reported optical limiting values from composites. Several materials characterization technique including SEM/TEM, Raman, AFM, UV-vis, adsorption and EDS were employed to characterize the physical and chemical properties of the carbon nanotubes, the functionalized carbon nanotubes and the nanocomposites synthesized in this project. These techniques allowed us to have a spectroscopic and morphological control of the composite formation and to understand the materials assembled. A parallel 136-CPU

  8. Fusion Power: A Strategic Choice for the Future Energy Provision. Why is So Much Time Wasted for Decision Making?

    SciTech Connect

    D'haeseleer, William D

    2005-04-15

    From a general analysis of the world energy issue, it is argued that an affordable, clean and reliable energy supply will have to consist of a portfolio of primary energy sources, a large fraction of which will be converted to a secondary carrier in large baseload plants. Because of all future uncertainties, it would be irresponsible not to include thermonuclear fusion as one of the future possibilities for electricity generation.The author tries to understand why nuclear-fusion research is not considered of strategic importance by the major world powers. The fusion programs of the USA and Europe are taken as prime examples to illustrate the 'hesitation'. Europe is now advocating a socalled 'fast-track' approach, thereby seemingly abandoning the 'classic' time frame towards fusion that it has projected for many years. The US 'oscillatory' attitude towards ITER in relation to its domestic program is a second case study that is looked at.From the real history of the ITER design and the 'siting' issue, one can try to understand how important fusion is considered by these world powers. Not words are important, but deeds. Fast tracks are nice to talk about, but timely decisions need to be taken and sufficient money is to be provided. More fundamental understanding of fusion plasma physics is important, but in the end, real hardware devices must be constructed to move along the path of power plant implementation.The author tries to make a balance of where fusion power research is at this moment, and where, according to his views, it should be going.

  9. Direct drive target survival during injection in an inertial fusion energy power plant

    NASA Astrophysics Data System (ADS)

    Petzoldt, R. W.; Goodin, D. T.; Nikroo, A.; Stephens, E.; Siegel, N.; Alexander, N. B.; Raffray, A. R.; Mau, T. K.; Tillack, M.; Najmabadi, F.; Krasheninnikov, S. I.; Gallix, R.

    2002-12-01

    In inertial fusion energy (IFE) power plant designs, the fuel is a spherical layer of frozen DT contained in a target that is injected at high velocity into the reaction chamber. For direct drive, typically laser beams converge at the centre of the chamber (CC) to compress and heat the target to fusion conditions. To obtain the maximum energy yield from the fusion reaction, the frozen DT layer must be at about 18.5 K and the target must maintain a high degree of spherical symmetry and surface smoothness when it reaches the CC. During its transit in the chamber the cryogenic target is heated by radiation from the hot chamber wall. The target is also heated by convection as it passes through the rarefied fill-gas used to control chamber wall damage by x-rays and debris from the target explosion. This article addresses the temperature limits at the target surface beyond which target uniformity may be damaged. It concentrates on direct drive targets because fuel warm up during injection is not currently thought to be an issue for present indirect drive designs and chamber concepts. Detailed results of parametric radiative and convective heating calculations are presented for direct-drive targets during injection into a dry-wall reaction chamber. The baseline approach to target survival utilizes highly reflective targets along with a substantially lower chamber wall temperature and fill-gas pressure than previously assumed. Recently developed high-Z material coatings with high heat reflectivity are discussed and characterized. The article also presents alternate target protection methods that could be developed if targets with inherent survival features cannot be obtained within a reasonable time span.

  10. Space fusion energy conversion using a field reversed configuration reactor: A new technical approach for space propulsion and power

    NASA Technical Reports Server (NTRS)

    Schulze, Norman R.; Miley, George H.; Santarius, John F.

    1991-01-01

    The fusion energy conversion design approach, the Field Reversed Configuration (FRC) - when burning deuterium and helium-3, offers a new method and concept for space transportation with high energy demanding programs, like the Manned Mars Mission and planetary science outpost missions require. FRC's will increase safety, reduce costs, and enable new missions by providing a high specific power propulsion system from a high performance fusion engine system that can be optimally designed. By using spacecraft powered by FRC's the space program can fulfill High Energy Space Missions (HESM) in a manner not otherwise possible. FRC's can potentially enable the attainment of high payload mass fractions while doing so within shorter flight times.

  11. Novel High Efficient Organic Photovoltaic Materials

    NASA Technical Reports Server (NTRS)

    Sun, Sam; Haliburton, James; Wang, Yi-Qing; Fan, Zhen; Taft, Charles; Maaref, Shahin; Bailey, Sheila (Technical Monitor)

    2003-01-01

    Solar energy is a renewable, nonpolluting, and most abundant energy source for human exploration of a remote site or outer space. In order to generate appreciable electrical power in space or on the earth, it is necessary to collect sunlight from large areas and with high efficiency due to the low density of sunlight. Future organic or polymer (plastic) solar cells appear very attractive due to their unique features such as light weight, flexible shape, tunability of energy band-gaps via versatile molecular or supramolecular design, synthesis, processing and device fabrication schemes, and much lower cost on large scale industrial production. It has been predicted that supramolecular and nano-phase separated block copolymer systems containing electron rich donor blocks and electron deficient acceptor blocks may facilitate the charge carrier separation and migration due to improved electronic ultrastructure and morphology in comparison to polymer composite system. This presentation will describe our recent progress in the design, synthesis and characterization of a novel block copolymer system containing donor and acceptor blocks covalently attached. Specifically, the donor block contains an electron donating alkyloxy derivatized polyphenylenevinylene (RO-PPV), the acceptor block contains an electron withdrawing alkyl-sulfone derivatized polyphenylenevinylene (SF-PPV). The key synthetic strategy includes the synthesis of each individual block first, then couple the blocks together. While the donor block has a strong PL emission at around 560 nm, and acceptor block has a strong PL emission at around 520 nm, the PL emissions of final block copolymers are severely quenched. This verifies the expected electron transfer and charge separation due to interfaces of donor and acceptor nano phase separated blocks. The system therefore has potential for variety light harvesting applications, including high efficient photovoltaic applications.

  12. The Mercury Laser System-A scaleable average-power laser for fusion and beyond

    SciTech Connect

    Ebbers, C A; Moses, E I

    2008-03-26

    Nestled in a valley between the whitecaps of the Pacific and the snowcapped crests of the Sierra Nevada, Lawrence Livermore National Laboratory (LLNL) is home to the nearly complete National Ignition Facility (NIF). The purpose of NIF is to create a miniature star-on demand. An enormous amount of laser light energy (1.8 MJ in a pulse that is 20 ns in duration) will be focused into a small gold cylinder approximately the size of a pencil eraser. Centered in the gold cylinder (or hohlraum) will be a nearly perfect sphere filled with a complex mixture of hydrogen gas isotopes that is similar to the atmosphere of our Sun. During experiments, the laser light will hit the inside of the gold cylinder, heating the metal until it emits X-rays (similar to how your electric stove coil emits visible red light when heated). The X-rays will be used to compress the hydrogen-like gas with such pressure that the gas atoms will combine or 'fuse' together, producing the next heavier element (helium) and releasing energy in the form of energetic particles. 2010 will mark the first credible attempt at this world-changing event: the achievement of fusion energy 'break-even' on Earth using NIF, the world's largest laser! NIF is anticipated to eventually perform this immense technological accomplishment once per week, with the capability of firing up to six shots per day - eliminating the need for continued underground testing of our nation's nuclear stockpile, in addition to opening up new realms of science. But what about the day after NIF achieves ignition? Although NIF will achieve fusion energy break-even and gain, the facility is not designed to harness the enormous potential of fusion for energy generation. A fusion power plant, as opposed to a world-class engineering research facility, would require that the laser deliver drive pulses nearly 100,000 times more frequently - a rate closer to 10 shots per second as opposed to several shots per day.

  13. Gas Transport and Control in Thick-Liquid Inertial Fusion PowerPlants

    SciTech Connect

    Debonnel, Christophe Sylvain

    2006-01-01

    Among the numerous potential routes to a commercial fusion power plant, the inertial path with thick-liquid protection is explored in this doctoral dissertation. Gas dynamics phenomena in such fusion target chambers have been investigated since the early 1990s with the help of a series of simulation codes known as TSUNAMI. For this doctoral work, the code was redesigned and rewritten entirely to enable the use of modern programming techniques, languages and software; improve its user-friendliness; and refine its ability to model thick-liquid protected chambers. The new ablation and gas dynamics code is named “Visual Tsunami” to emphasize its graphics-based pre- and post-processors. It is aimed at providing a versatile and user-friendly design tool for complex systems for which transient gas dynamics phenomena play a key role. Simultaneously, some of these improvements were implemented in a previous version of the code; the resulting code constitutes the version 2.8 of the TSUNAMI series. Visual Tsunami was used to design and model the novel Condensation Debris Experiment (CDE), which presents many aspects of a typical Inertial Fusion Energy (IFE) system and has therefore been used to exercise the code. Numerical and experimental results are in good agreement. In a heavy-ion IFE target chamber, proper beam and target propagation set stringent requirements for the control of ablation debris transport in the target chamber and beam tubes. When the neutralized ballistic transport mode is employed, the background gas density should be adequately low and the beam tube metallic surfaces upstream of the neutralizing region should be free of contaminants. TSUNAMI 2.8 was used for the first simulation of gas transport through the complex geometry of the liquid blanket of a hybrid target chamber and beam lines. Concurrently, the feasibility of controlling the gas density was addressed with a novel beam tube design, which introduces magnetic shutters and a long low

  14. Highly efficient Raman distributed feedback fibre lasers.

    PubMed

    Shi, Jindan; Alam, Shaif-ul; Ibsen, Morten

    2012-02-27

    We demonstrate highly efficient Raman distributed feedback (DFB) fibre lasers for the first time with up to 1.6 W of continuous wave (CW) output power. The DFB Bragg gratings are written directly into two types of commercially available passive germano-silica fibres. Two lasers of 30 cm length are pumped with up to 15 W of CW power at 1068 nm. The threshold power is ~2 W for a Raman-DFB (R-DFB) laser written in standard low-NA fibre, and only ~1 W for a laser written in a high-NA fibre, both of which oscillate in a narrow linewidth of <0.01 nm at ~1117 nm and ~1109 nm, respectively. The slope efficiencies are ~74% and ~93% with respect to absorbed pump power in the low-NA fibre and high-NA fibre respectively. Such high conversion efficiency suggests that very little energy is lost in the form of heat through inefficient energy transfer. Our results are supported by numerical simulations, and furthermore open up for the possibility of having narrow linewidth all-fibre laser sources in wavelength bands not traditionally covered by rare-earth doped silica fibres. Simulations also imply that this technology has the potential to produce even shorter R-DFB laser devices at the centimetre-level and with mW-level thresholds, if Bragg gratings formed in fibre materials with higher intrinsic Raman gain coefficient than silica are used. These materials include for example tellurite or chalcogenide glasses. Using glasses like these would also open up the possibility of having narrow linewidth fibre sources with DFB laser oscillating much further into the IR than what currently is possible with rare-earth doped silica glasses.

  15. VISTA -- A Vehicle for Interplanetary Space Transport Application Powered by Inertial Confinement Fusion

    SciTech Connect

    Orth, C D

    2005-03-31

    Inertial Confinement Fusion (ICF) is an ideal technology to power self-contained single-stage piloted (manned) spacecraft within the solar system because of its inherently high power/mass ratios and high specific impulses (i.e., high exhaust velocities). These technological advantages are retained when ICF is utilized with a magnetic thrust chamber, which avoids the plasma thermalization and resultant degradation of specific impulse that are unavoidable with the use of mechanical thrust chambers. We started with Rod Hyde's 1983 description of an ICF-powered engine concept using a magnetic thrust chamber, and conducted a more detailed systems study to develop a viable, realistic, and defensible spacecraft concept based on ICF technology projected to be available in the first half of the 21st century. The results include an entirely new conical spacecraft conceptual design utilizing near-existing radiator technology. We describe the various vehicle systems for this new concept, estimate the missions performance capabilities for general missions to the planets within the solar system, and describe in detail the performance for the baseline mission of a piloted roundtrip to Mars with a 100-ton payload. For this mission, we show that roundtrips totaling {ge}145 days are possible with advanced DT fusion technology and a total (wet) spacecraft mass of about 6000 metric tons. Such short-duration missions are advantageous to minimize the known cosmic-radiation hazards to astronauts, and are even more important to minimize the physiological deteriorations arising from zero gravity. These ICF-powered missions are considerably faster than those available using chemical or nuclear-electric-propulsion technologies with minimum-mass vehicle configurations. VISTA also offers onboard artificial gravity and propellant-based shielding from cosmic rays, thus reducing the known hazards and physiological deteriorations to insignificant levels. We emphasize, however, that the degree to

  16. Transport and deposition of activation products in a helium cooled fusion power plant

    SciTech Connect

    Bickford, W.E.

    1980-09-01

    The transport and deposition of neutron activation products in a helium cooled tokamak fusion power plant are investigated. Stainless steel is used as coolant channel material for a helium/steam system. The important gamma emitting nuclides /sup 56/Mn, /sup 54/Mn, /sup 57/Co, /sup 58/Co, /sup 60/Co, /sup 51/Cr, and /sup 99/Mo are considered. The dominant release mechanism identified is direct daughter recoil emission from (n,x) type reactions. Corrosion and evaporation are discussed. The radionuclide inventory released by these mechanisms is predicted to exceed 1 x 10/sup 4/ Ci for a reference reactor design after only several days of operation, and approach 3.5 x 10/sup 4/ Ci in equilibrium. A mass transport model is then used to predict the deposition pattern of this inventory in the reactor cooling system.

  17. A Snowflake Divertor: a Possible Way of Improving the Power Handling in Future Fusion Facilities

    SciTech Connect

    Ryutov, D D; Bulmer, R H; Cohen, R H; Hill, D N; Lao, L; Menard, J E; Petrie, T W; Pearlstein, L D; Rognlien, T D; Snyder, P B; Soukhanovskii, V; Umansky, M V

    2008-09-17

    Handling high power loads on plasma facing components is one of the critical issues in developing an economically competitive fusion reactor based on tokamak. In this study, we provide a detailed analysis of a relatively unexplored approach to this problem based on the use of divertors with the poloidal magnetic field structure closely approaching a second-order null. We demonstrate that this geometry opens up new possibilities for radiative divertors, has favorable effect on the convective transport, and provides an additional control over ELM activity. In the ideal case where the null is exactly second order, the separatrix near the null acquires a characteristic hexagonal shape reminiscent of a snowflake, whence the name of this configuration. It can be created by a simple set of divertor coils situated outside the toroidal field coils.

  18. Development of high power radio frequency components for fusion plasma heating. Final report, Revision 3

    SciTech Connect

    1997-09-11

    The purpose of this CRADA was to develop advanced microwave heating systems for both ion cyclotron heating and electron cyclotron heating for magnetic fusion reactors. This involved low-frequency (UHF), high-power (millimeter-wave) microwave components, such as antennas, windows, and matching elements. This CRADA also involved developing conceptual designs for new microwave sources. General Atomics built and tested the distributed cooled window and provided LLNL with transmission and reflection test data in order to then benchmark the EM computer codes. The combline antenna built and analyzed by LLNL was based on a GA design. GA provided LLNL with a number of niobium plates for hot pressing and provided the necessary guidance to allow successful bonding. GA representatives were on site at LLNL on numerous occasions to consult and give guidance on the ferroelectric tuner, combline antenna and distributed window analysis.

  19. High efficiency turbine blade coatings

    SciTech Connect

    Youchison, Dennis L.; Gallis, Michail A.

    2014-06-01

    The development of advanced thermal barrier coatings (TBCs) of yttria stabilized zirconia (YSZ) that exhibit lower thermal conductivity through better control of electron beam - physical vapor deposition (EB-PVD) processing is of prime interest to both the aerospace and power industries. This report summarizes the work performed under a two-year Lab-Directed Research and Development (LDRD) project (38664) to produce lower thermal conductivity, graded-layer thermal barrier coatings for turbine blades in an effort to increase the efficiency of high temperature gas turbines. This project was sponsored by the Nuclear Fuel Cycle Investment Area. Therefore, particular importance was given to the processing of the large blades required for industrial gas turbines proposed for use in the Brayton cycle of nuclear plants powered by high temperature gas-cooled reactors (HTGRs). During this modest (~1 full-time equivalent (FTE)) project, the processing technology was developed to create graded TBCs by coupling ion beam-assisted deposition (IBAD) with substrate pivoting in the alumina-YSZ system. The Electron Beam - 1200 kW (EB-1200) PVD system was used to deposit a variety of TBC coatings with micron layered microstructures and reduced thermal conductivity below 1.5 W/m.K. The use of IBAD produced fully stoichiometric coatings at a reduced substrate temperature of 600°C and a reduced oxygen background pressure of 0.1 Pa. IBAD was also used to successfully demonstrate the transitioning of amorphous PVD-deposited alumina to the -phase alumina required as an oxygen diffusion barrier and for good adhesion to the substrate Ni2Al3 bondcoat. This process replaces the time consuming thermally grown oxide formation required before the YSZ deposition. In addition to the process technology, Direct Simulation Monte Carlo plume modeling and spectroscopic characterization of the PVD plumes were performed. The project consisted of five tasks. These included the

  20. High efficiency thermionic converter studies

    NASA Technical Reports Server (NTRS)

    Huffman, F. N.; Sommer, A. H.; Balestra, C. L.; Briere, D. P.; Oettinger, P. E.

    1976-01-01

    The objective is to improve thermionic converter performance by means of reduced interelectrode losses, greater emitter capabilities, and lower collector work functions until the converter performance level is suitable for out-of-core space reactors and radioisotope generators. Electrode screening experiments have identified several promising collector materials. Back emission work function measurements of a ZnO collector in a thermionic diode have given values less than 1.3 eV. Diode tests were conducted over the range of temperatures of interest for space power applications. Enhanced mode converter experiments have included triodes operated in both the surface ionization and plasmatron modes. Pulsed triodes were studied as a function of pulse length, pulse potential, inert gas fill pressure, cesium pressure, spacing, emitter temperature and collector temperature. Current amplifications (i.e., mean output current/mean grid current) of several hundred were observed up to output current densities of one amp/sq cm. These data correspond to an equivalent arc drop less than 0.1 eV.

  1. Multiscale integral analysis of a HT leakage in a fusion nuclear power plant

    NASA Astrophysics Data System (ADS)

    Velarde, M.; Fradera, J.; Perlado, J. M.; Zamora, I.; Martínez-Saban, E.; Colomer, C.; Briani, P.

    2016-05-01

    The present work presents an example of the application of an integral methodology based on a multiscale analysis that covers the whole tritium cycle within a nuclear fusion power plant, from a micro scale, analyzing key components where tritium is leaked through permeation, to a macro scale, considering its atmospheric transport. A leakage from the Nuclear Power Plants, (NPP) primary to the secondary side of a heat exchanger (HEX) is considered for the present example. Both primary and secondary loop coolants are assumed to be He. Leakage is placed inside the HEX, leaking tritium in elementary tritium (HT) form to the secondary loop where it permeates through the piping structural material to the exterior. The Heating Ventilation and Air Conditioning (HVAC) system removes the leaked tritium towards the NPP exhaust. The HEX is modelled with system codes and coupled to Computational Fluid Dynamic (CFD) to account for tritium dispersion inside the nuclear power plants buildings and in site environment. Finally, tritium dispersion is calculated with an atmospheric transport code and a dosimetry analysis is carried out. Results show how the implemented methodology is capable of assessing the impact of tritium from the microscale to the atmospheric scale including the dosimetric aspect.

  2. Reactor for boron fusion with picosecond ultrahigh power laser pulses and ultrahigh magnetic field trapping

    NASA Astrophysics Data System (ADS)

    Miley, G. H.; Hora, H.; Kirchhoff, G.

    2016-05-01

    Compared with the deuterium tritium (DT) fusion, the environmentally clean fusion of protons with 11B is extremely difficult. When instead of nanosecond laser pulses for thermal-ablating driven ignition, picosecond pulses are used, a drastic change by nonlinearity results in ultrahigh acceleration of plasma blocks. This radically changes to economic boron fusion by a measured new avalanche ignition.

  3. Applications of ion implantation for high efficiency silicon solar cells

    NASA Technical Reports Server (NTRS)

    Minnucci, J. A.; Kirkpatrick, A. R.

    1977-01-01

    Ion implantation is utilized for the dopant introduction processes necessary to fabricate a silicon solar cell. Implantation provides a versatile powerful tool for development of high efficiency cells. Advantages and problems of implantation and the present status of developmental use of the technique for solar cells are discussed.

  4. Creating a Star: The Science of Fusion--Fusion Power Would Not Contribute to Global Warming, Acid Rain, or Other Forms of Air Pollution, nor Would It Create Long-Lived Radioactive Waste

    ERIC Educational Resources Information Center

    Baird, Stephen L.

    2005-01-01

    Fusion is the process that powers the sun and the stars. Since the 1950s, scientists and engineers in the United States and around the world have been conducting fusion research in pursuit of the creation of a new energy source for our planet and to further our understanding and control of plasma, the fourth state of matter that dominates the…

  5. Commercial objectives, technology transfer, and systems analysis for fusion power development

    NASA Technical Reports Server (NTRS)

    Dean, Stephen O.

    1988-01-01

    Fusion is an inexhaustible source of energy that has the potential for economic commercial applications with excellent safety and environmental characteristics. The primary focus for the fusion energy development program is the generation of central station electricity. Fusion has the potential, however, for many other applications. The fact that a large fraction of the energy released in a DT fusion reaction is carried by high energy neutrons suggests potentially unique applications. In addition, fusion R and D will lead to new products and new markets. Each fusion application must meet certain standards of economic and safety and environmental attractiveness. For this reason, economics on the one hand, and safety and environment and licensing on the other, are the two primary criteria for setting long range commercial fusion objectives. A major function of systems analysis is to evaluate the potential of fusion against these objectives and to help guide the fusion R and D program toward practical applications. The transfer of fusion technology and skills from the national labs and universities to industry is the key to achieving the long range objective of commercial fusion applications.

  6. The Gevaltig: An inertial fusion powered manned spacecraft design for outer solar system missions

    SciTech Connect

    Murray, K.A.

    1989-10-01

    The Gevaltig is an inertial fusion powered rocket engine capable of manned missions to other planets with round trip mission times as low as 100 days. The Gevaltig design was previously described for a mission to Mars. This effort defines the spacecraft components in terms of mass and presents a mission analysis for a manned trip to Titan, a moon of Saturn. The Gevaltig component masses are provided as a function of fuel pellet ignition frequency. These variable mass components include the fuel tanks, radiators, structure and EM pumps. Fixed mass components include the drivers, coil, coil shield, power processing system, payload, crew shield and laser mirrors. A 6 MW nuclear reactor is included in the design for startup purposes. Various combinations of thrust, mission duration and specific impulse were evaluated to determine a reasonable mission scenario for the Titan mission. The mission analysis yielded several viable mission scenarios, with round trip durations of 370 to 500 days and initial (launch) masses from lunar orbit of 2500 to 20,000 metric tons. 15 refs., 13 figs., 14 tabs.

  7. Multi-petascale highly efficient parallel supercomputer

    DOEpatents

    Asaad, Sameh; Bellofatto, Ralph E.; Blocksome, Michael A.; Blumrich, Matthias A.; Boyle, Peter; Brunheroto, Jose R.; Chen, Dong; Cher, Chen -Yong; Chiu, George L.; Christ, Norman; Coteus, Paul W.; Davis, Kristan D.; Dozsa, Gabor J.; Eichenberger, Alexandre E.; Eisley, Noel A.; Ellavsky, Matthew R.; Evans, Kahn C.; Fleischer, Bruce M.; Fox, Thomas W.; Gara, Alan; Giampapa, Mark E.; Gooding, Thomas M.; Gschwind, Michael K.; Gunnels, John A.; Hall, Shawn A.; Haring, Rudolf A.; Heidelberger, Philip; Inglett, Todd A.; Knudson, Brant L.; Kopcsay, Gerard V.; Kumar, Sameer; Mamidala, Amith R.; Marcella, James A.; Megerian, Mark G.; Miller, Douglas R.; Miller, Samuel J.; Muff, Adam J.; Mundy, Michael B.; O'Brien, John K.; O'Brien, Kathryn M.; Ohmacht, Martin; Parker, Jeffrey J.; Poole, Ruth J.; Ratterman, Joseph D.; Salapura, Valentina; Satterfield, David L.; Senger, Robert M.; Smith, Brian; Steinmacher-Burow, Burkhard; Stockdell, William M.; Stunkel, Craig B.; Sugavanam, Krishnan; Sugawara, Yutaka; Takken, Todd E.; Trager, Barry M.; Van Oosten, James L.; Wait, Charles D.; Walkup, Robert E.; Watson, Alfred T.; Wisniewski, Robert W.; Wu, Peng

    2015-07-14

    A Multi-Petascale Highly Efficient Parallel Supercomputer of 100 petaOPS-scale computing, at decreased cost, power and footprint, and that allows for a maximum packaging density of processing nodes from an interconnect point of view. The Supercomputer exploits technological advances in VLSI that enables a computing model where many processors can be integrated into a single Application Specific Integrated Circuit (ASIC). Each ASIC computing node comprises a system-on-chip ASIC utilizing four or more processors integrated into one die, with each having full access to all system resources and enabling adaptive partitioning of the processors to functions such as compute or messaging I/O on an application by application basis, and preferably, enable adaptive partitioning of functions in accordance with various algorithmic phases within an application, or if I/O or other processors are underutilized, then can participate in computation or communication nodes are interconnected by a five dimensional torus network with DMA that optimally maximize the throughput of packet communications between nodes and minimize latency.

  8. The Information Fusion Embrittlement Models for U.S. Power Reactor Pressure Vessel Steels

    SciTech Connect

    Wang, Jy-An John; Rao, Nageswara S; Konduri, Savanthi

    2007-01-01

    The complex nonlinear dependencies observed in typical reactor pressure vessel (RPV) material embrittlement data, as well as the inherent large uncertainties and scatter in the radiation embrittlement data, make prediction of radiation embrittlement a difficult task. Conventional statistical and deterministic approaches have only resulted in rather large uncertainties, in part because they do not fully exploit domain-specific mechanisms. The domain models built by researchers in the field, on the other hand, do not fully exploit the statistical and information content of the data. As evidenced in previous studies, it is unlikely that a single method, whether statistical, nonlinear, or domain model, will outperform all others. More generally, considering the complexity of the embrittlement prediction problem, it is highly unlikely that a single best method exists and is tractable, even in theory. In this paper, we propose to combine a number of complementary methods including domain models, neural networks, and nearest neighbor regressions (NNRs). Such a combination of methods has become possible because of recent developments in measurement-based optimal fusers in the area of information fusion. The information fusion technique is used to develop radiation embrittlement prediction models for reactor RPV steels from U.S. power reactors, including boiling water reactors and pressurized water reactors. The Charpy transition temperature-shift data is used as the primary index of RPV radiation embrittlement in this study. Six Cu, Ni, P, neutron fluence, irradiation time, and irradiation-parameters are used in the embrittlement prediction models. The results-temperature indicate that this new embrittlement predictor achieved reductions of about 49.5% and 52% in the uncertainties for plate and weld data, respectively, for pressurized water reactor and boiling water reactor data, compared with the Nuclear Regulatory Commission Regulatory Guide 1.99, Rev. 2. The

  9. Overview of the VISTA Spacecraft Concept Powered by Inertial Confinement Fusion

    SciTech Connect

    Orth, C D

    2000-11-21

    VISTA was conceived through a detailed systems analysis as a viable, realistic, and defensible spacecraft concept based on advanced ICF technology but existing or near-term technology for other systems. It is a conical self-contained single-stage piloted spacecraft in which a magnetic thrust chamber directs the plasma emissions from inertial confinement fusion (ICF) targets into a rearward exhaust. VISTA's propulsion system is therefore unique because it is based on (1) a rather mature technology (ICF), which is known to work with sufficient driver input; (2) direct heating of all expellant by the fusion process, thus providing high mass flow rates without significant degradation of jet efficiency; and (3) a magnetic thrust chamber, which avoids the plasma thermalization and resultant degradation of specific impulse that are unavoidable with the use of mechanical thrust chambers. VISTA therefore has inherently high power/mass ratios and high specific impulses. With advanced ICF technology, ultra-fast roundtrips (RTs) to objects within the solar system are possible (e.g., {ge}145 days RT to Mars, {ge}7 years RT to Pluto). Such short-duration missions are imperative to minimize the human physiological deteriorations arising from zero gravity and the cosmic-radiation. In addition, VISTA offers on-board artificial gravity and propellant-based shielding from cosmic rays, thus reducing the physiological deteriorations to insignificant levels. In this paper, we give an overview of the various vehicle systems for this concept, estimate the general missions performance capabilities for interplanetary missions, and describe in detail the performance for the baseline mission of a piloted roundtrip to Mars with a 100-ton payload. Items requiring further research include a reduction of the wet mass from its baseline value of 6,000 metric tons, and the development of fast ignition or its equivalent to provide target gains in excess of several hundred. With target gains well

  10. Scaling magnetized liner inertial fusion on Z and future pulsed-power accelerators

    SciTech Connect

    Slutz, S. A.; Stygar, W. A.; Gomez, M. R.; Peterson, K. J.; Sefkow, A. B.; Sinars, D. B.; Vesey, R. A.; Campbell, E. M.; Betti, R.

    2016-02-15

    The MagLIF (Magnetized Liner Inertial Fusion) concept [S. A. Slutz et al., Phys. Plasmas 17, 056303 (2010)] has demonstrated fusion–relevant plasma conditions [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)] on the Z accelerator with a peak drive current of about 18 MA. We present 2D numerical simulations of the scaling of MagLIF on Z as a function of drive current, preheat energy, and applied magnetic field. The results indicate that deuterium-tritium (DT) fusion yields greater than 100 kJ could be possible on Z when all of these parameters are at the optimum values: i.e., peak current = 25 MA, deposited preheat energy = 5 kJ, and B{sub z} = 30 T. Much higher yields have been predicted [S. A. Slutz and R. A. Vesey, Phys. Rev. Lett. 108, 025003 (2012)] for MagLIF driven with larger peak currents. Two high performance pulsed-power accelerators (Z300 and Z800) based on linear-transformer-driver technology have been designed [W. A. Stygar et al., Phys. Rev. ST Accel. Beams 18, 110401 (2015)]. The Z300 design would provide 48 MA to a MagLIF load, while Z800 would provide 65 MA. Parameterized Thevenin-equivalent circuits were used to drive a series of 1D and 2D numerical MagLIF simulations with currents ranging from what Z can deliver now to what could be achieved by these conceptual future pulsed-power accelerators. 2D simulations of simple MagLIF targets containing just gaseous DT have yields of 18 MJ for Z300 and 440 MJ for Z800. The 2D simulated yield for Z800 is increased to 7 GJ by adding a layer of frozen DT ice to the inside of the liner.

  11. Multi Band Gap High Efficiency Converter (RAINBOW)

    NASA Technical Reports Server (NTRS)

    Bekey, I.; Lewis, C.; Phillips, W.; Shields, V.; Stella, P.

    1997-01-01

    The RAINBOW multi band gap system represents a unique combination of solar cells, concentrators and beam splitters. RAINBOW is a flexible system which can readily expand as new high efficiency components are developed.

  12. High efficiency flat plate solar energy collector

    SciTech Connect

    Butler, R. F.

    1985-04-30

    A concentrating flat plate collector for the high efficiency collection of solar energy. Through an arrangement of reflector elements, incoming solar radiation, either directly or after reflection from the reflector elements, impinges upon both surfaces of a collector element.

  13. Novel High Efficient Organic Photovoltaic Materials

    NASA Technical Reports Server (NTRS)

    Sun, Sam; Haliburton, James; Fan, Zben; Taft, Charles; Wang, Yi-Qing; Maaref, Shahin; Mackey, Willie R. (Technical Monitor)

    2001-01-01

    In man's mission to the outer space or a remote site, the most abundant, renewable, nonpolluting, and unlimited external energy source is light. Photovoltaic (PV) materials can convert light into electrical power. In order to generate appreciable electrical power in space or on the Earth, it is necessary to collect sunlight from large areas due to the low density of sunlight, and this would be very costly using current commercially available inorganic solar cells. Future organic or polymer based solar cells seemed very attractive due to several reasons. These include lightweight, flexible shape, ultra-fast optoelectronic response time (this also makes organic PV materials attractive for developing ultra-fast photo detectors), tunability of energy band-gaps via molecular design, versatile materials synthesis and device fabrication schemes, and much lower cost on large-scale industrial production. It has been predicted that nano-phase separated block copolymer systems containing electron rich donor blocks and electron deficient acceptor blocks will facilitate the charge separation and migration due to improved electronic ultrastructure and morphology in comparison to current polymer composite photovoltaic system. This presentation will describe our recent progress in the design, synthesis and characterization of a novel donor-bridge-acceptor block copolymer system for potential high-efficient organic optoelectronic applications. Specifically, the donor block contains an electron donating alkyloxy derivatized polyphenylenevinylene, the acceptor block contains an electron withdrawing alkyl-sulfone derivatized polyphenylenevinylene, and the bridge block contains an electronically neutral non-conjugated aliphatic hydrocarbon chain. The key synthetic strategy includes the synthesis of each individual block first, then couple the blocks together. While the donor block stabilizes the holes, the acceptor block stabilizes the electrons. The bridge block is designed to hinder

  14. The Development of SiC MOSFET-based Switching Power Amplifiers for Fusion Science

    NASA Astrophysics Data System (ADS)

    Prager, James; Ziemba, Timothy; Miller, Kenneth; Picard, Julian

    2015-11-01

    Eagle Harbor Technologies (EHT), Inc. is developing a switching power amplifier (SPA) based on silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET). SiC MOSFETs offer many advantages over IGBTs including lower drive energy requirements, lower conduction and switching losses, and higher switching frequency capabilities. When comparing SiC and traditional silicon-based MOSFETs, SiC MOSFETs provide higher current carrying capability allowing for smaller package weights and sizes and lower operating temperature. EHT has conducted single device testing that directly compares the capabilities of SiC MOSFETs and IGBTs to demonstrate the utility of SiC MOSFETs for fusion science applications. These devices have been built into a SPA that can drive resistive loads and resonant tank loads at 800 V, 4.25 kA at pulse repetition frequencies up to 1 MHz. During the Phase II program, EHT will finalize the design of the SPA. In Year 2, EHT will replace the SPAs used in the HIT-SI lab at the University of Washington to allow for operation over 100 kHz. SPA prototype results will be presented. This work is supported under DOE Grant # DE-SC0011907.

  15. Physics Basis for the Advanced Tokamak Fusion Power Plant ARIES-AT

    SciTech Connect

    S.C. Jardin; C.E. Kessel; T.K. Mau; R.L. Miller; F. Najmabadi; V.S. Chan; M.S. Chu; R. LaHaye; L.L. Lao; T.W. Petrie; P. Politzer; H.E. St. John; P. Snyder; G.M. Staebler; A.D. Turnbull; W.P. West

    2003-10-07

    The advanced tokamak is considered as the basis for a fusion power plant. The ARIES-AT design has an aspect ratio of A always equal to R/a = 4.0, an elongation and triangularity of kappa = 2.20, delta = 0.90 (evaluated at the separatrix surface), a toroidal beta of beta = 9.1% (normalized to the vacuum toroidal field at the plasma center), which corresponds to a normalized beta of bN * 100 x b/(I(sub)P(MA)/a(m)B(T)) = 5.4. These beta values are chosen to be 10% below the ideal-MHD stability limit. The bootstrap-current fraction is fBS * I(sub)BS/I(sub)P = 0.91. This leads to a design with total plasma current I(sub)P = 12.8 MA, and toroidal field of 11.1 T (at the coil edge) and 5.8 T (at the plasma center). The major and minor radii are 5.2 and 1.3 m, respectively. The effects of H-mode edge gradients and the stability of this configuration to non-ideal modes is analyzed. The current-drive system consists of ICRF/FW for on-axis current drive and a lower-hybrid system for off-axis. Tran sport projections are presented using the drift-wave based GLF23 model. The approach to power and particle exhaust using both plasma core and scrape-off-layer radiation is presented.

  16. A High-Efficiency Superhydrophobic Plasma Separator

    PubMed Central

    Liu, Changchun; Liao, Shih-Chuan; Song, Jinzhao; Mauk, Michael G.; Li, Xuanwen; Wu, Gaoxiang; Ge, Dengteng; Greenberg, Robert M.; Yang, Shu; Bau, Haim H.

    2016-01-01

    To meet stringent limit-of-detection specifications for low abundance target molecules, a relatively large volume of plasma is needed for many blood-based clinical diagnostics. Conventional centrifugation methods for plasma separation are not suitable for on-site testing or bedside diagnostics. Here, we report a simple, yet high-efficiency, clamshell-style, superhydrophobic plasma separator that is capable of separating a relatively large volume of plasma from several hundred microliters of whole blood (finger-prick blood volume). The plasma separator consists of a superhydrophobic top cover with a separation membrane and a superhydrophobic bottom substrate. Unlike previously reported membrane-based plasma separators, the separation membrane in our device is positioned at the top of the sandwiched whole blood film to increase the membrane separation capacity and plasma yield. In addition, the device’s superhydrophobic characteristics (i) facilitates the formation of well-defined, contracted, thin blood film with a high contact angle; (ii) minimizes biomolecular adhesion to surfaces; (iii) increases blood clotting time; and (iv) reduces blood cell hemolysis. The device demonstrated a “blood in-plasma out” capability, consistently extracting 65±21.5 μL of plasma from 200 μL of whole blood in less than 10 min without electrical power. The device was used to separate plasma from Schistosoma mansoni genomic DNA-spiked whole blood with a recovery efficiency of > 84.5 ± 25.8 %. The S. mansoni genomic DNA in the separated plasma was successfully tested on our custom-made microfluidic chip by using loop mediated isothermal amplification (LAMP) method. PMID:26732765

  17. A high-efficiency superhydrophobic plasma separator.

    PubMed

    Liu, Changchun; Liao, Shih-Chuan; Song, Jinzhao; Mauk, Michael G; Li, Xuanwen; Wu, Gaoxiang; Ge, Dengteng; Greenberg, Robert M; Yang, Shu; Bau, Haim H

    2016-02-07

    To meet stringent limit-of-detection specifications for low abundance target molecules, a relatively large volume of plasma is needed for many blood-based clinical diagnostics. Conventional centrifugation methods for plasma separation are not suitable for on-site testing or bedside diagnostics. Here, we report a simple, yet high-efficiency, clamshell-style, superhydrophobic plasma separator that is capable of separating a relatively large volume of plasma from several hundred microliters of whole blood (finger-prick blood volume). The plasma separator consists of a superhydrophobic top cover with a separation membrane and a superhydrophobic bottom substrate. Unlike previously reported membrane-based plasma separators, the separation membrane in our device is positioned at the top of the sandwiched whole blood film to increase the membrane separation capacity and plasma yield. In addition, the device's superhydrophobic characteristics (i) facilitates the formation of well-defined, contracted, thin blood film with a high contact angle; (ii) minimizes biomolecular adhesion to surfaces; (iii) increases blood clotting time; and (iv) reduces blood cell hemolysis. The device demonstrated a "blood in-plasma out" capability, consistently extracting 65 ± 21.5 μL of plasma from 200 μL of whole blood in less than 10 min without electrical power. The device was used to separate plasma from Schistosoma mansoni genomic DNA-spiked whole blood with a recovery efficiency of >84.5 ± 25.8%. The S. mansoni genomic DNA in the separated plasma was successfully tested on our custom-made microfluidic chip by using loop mediated isothermal amplification (LAMP) method.

  18. Important loss mechanisms in high-efficiency solar cells

    NASA Technical Reports Server (NTRS)

    Sah, C. T.

    1984-01-01

    A study was conducted to identify loss mechanisms in high efficiency silicon solar cells. The following were considered: (1) recombination loss mechanisms; (2) high efficiency cells; (3) very high efficiency cells; and (4) ultra high efficiency cells.

  19. The Fusion Energy Option

    NASA Astrophysics Data System (ADS)

    Dean, Stephen O.

    2004-06-01

    Presentations from a Fusion Power Associates symposium, The Fusion Energy Option, are summarized. The topics include perspectives on fossil fuel reserves, fusion as a source for hydrogen production, status and plans for the development of inertial fusion, planning for the construction of the International Thermonuclear Experimental Reactor, status and promise of alternate approaches to fusion and the need for R&D now on fusion technologies.

  20. Fusion materials: Technical evaluation of the technology of vandium alloys for use as blanket structural materials in fusion power systems

    SciTech Connect

    Not Available

    1993-08-04

    The Committee`s evaluation of vanadium alloys as a structural material for fusion reactors was constrained by limited data and time. The design of the International Thermonuclear Experimental Reactor is still in the concept stage, so meaningful design requirements were not available. The data on the effect of environment and irradiation on vanadium alloys were sparse, and interpolation of these data were made to select the V-5Cr-5Ti alloy. With an aggressive, fully funded program it is possible to qualify a vanadium alloy as the principal structural material for the ITER blanket in the available 5 to 8-year window. However, the data base for V-5Cr-5Ti is United and will require an extensive development and test program. Because of the chemical reactivity of vanadium the alloy will be less tolerant of system failures, accidents, and off-normal events than most other candidate blanket structural materials and will require more careful handling during fabrication of hardware. Because of the cost of the material more stringent requirements on processes, and minimal historical worlding experience, it will cost an order of magnitude to qualify a vanadium alloy for ITER blanket structures than other candidate materials. The use of vanadium is difficult and uncertain; therefore, other options should be explored more thoroughly before a final selection of vanadium is confirmed. The Committee views the risk as being too high to rely solely on vanadium alloys. In viewing the state and nature of the design of the ITER blanket as presented to the Committee, h is obvious that there is a need to move toward integrating fabrication, welding, and materials engineers into the ITER design team. If the vanadium allay option is to be pursued, a large program needs to be started immediately. The commitment of funding and other resources needs to be firm and consistent with a realistic program plan.

  1. High Power LaB6 Plasma Source Performance for the Lockheed Martin Compact Fusion Reactor Experiment

    NASA Astrophysics Data System (ADS)

    Heinrich, Jonathon

    2016-10-01

    Lockheed Martin's Compact Fusion Reactor (CFR) concept is a linear encapsulated ring cusp. Due to the complex field geometry, plasma injection into the device requires careful consideration. A high power thermionic plasma source (>0.25MW; >10A/cm2) has been developed with consideration to phase space for optimal coupling. We present the performance of the plasma source, comparison with alternative plasma sources, and plasma coupling with the CFR field configuration. ©2016 Lockheed Martin Corporation. All Rights Reserved.

  2. High efficiency cw laser-pumped tunable alexandrite laser

    SciTech Connect

    Lai, S.T.; Shand, M.L.

    1983-10-01

    High efficiency cw alexandrite laser operation has been achieved. With longitudinal pumping by a krypton laser in a nearly concentric cavity, a 51% output power slope efficiency has been measured. Including the transmission at the input coupler mirror, a quantum yield of 85% has been attained above threshold. Tunability from 726 to 802 nm has also been demonstrated. The low loss and good thermal properties make alexandrite ideal for cw laser operation.

  3. A high efficiency 3 kW switchmode battery charger

    NASA Technical Reports Server (NTRS)

    Latos, T. S.; Bosack, D. J.

    1982-01-01

    This paper discusses the design approach and status of a high-efficiency switchmode battery charger designed to charge a 108 V battery from the 115 Vac line. The charger contains a transformer isolated boost chopper operating at 20 kHz. The boost inductor current is programmed to follow the ac line voltage such that high power factor operation and low line distortion are obtained.

  4. Enhanced ceria solid electrolyte fuel cell development. Reduction of electronic conductivity permits use of a solid ceria electrolyte in high efficiency high power density fuel cells at temperatures compatible with metallic cell hardware

    NASA Astrophysics Data System (ADS)

    Maricle, D. L.

    1990-01-01

    The high operating temperature of zirconia based solid oxide fuel cells has been shown in many studies to have advantages for both space and terrestrial applications. The high heat rejection temperature minimizes radiator size and weight for high atmospheric and space applications. Mobile and stationary terrestrial applications take advantage of a cell temperature high enough to directly reform hydro-carbon fuels, achieving high efficiency and energy density. Government funded solid oxide fuel cell (SOFC) efforts are concentrated on the monolithic and tubular cell designs employing zirconia as the oxide ion conduction membrane. Zirconia requires an operating temperature of 1000 C to achieve adequate electrolyte conductivity. All-ceramic cell structures are used in both cases, leading to fragile, failure prone cells, and manufacturing steps which are difficult to scale up and costly. IFC's molten carbonate fuel cell development demonstrates the reliability of ductile sheet metal parts used for gas flow fields, separator plates, and frames in the 650 C temperature range. Ceria doped with gadolinium has ionic conductivity at 700 C comparable to zirconia at 1000 C. At 700 C a variety of stainless steels offer acceptable strength and oxidation resistance for use as cell hardware.

  5. High Efficient Universal Buck Boost Solar Array Regulator SAR Module

    NASA Astrophysics Data System (ADS)

    Kimmelmann, Stefan; Knorr, Wolfgang

    2014-08-01

    The high efficient universal Buck Boost Solar Array Regulator (SAR) module concept is applicable for a wide range of input and output voltages. The single point failure tolerant SAR module contains 3 power converters for the transfer of the SAR power to the battery dominated power bus. The converters are operating parallel in a 2 out of 3 redundancy and are driven by two different controllers. The output power of one module can be adjusted up to 1KW depending on the requirements. The maximum power point tracker (MPPT) is placed on a separate small printed circuit board and can be used if no external tracker signal is delivered. Depending on the mode and load conditions an efficiency of more than 97% is achievable. The stable control performance is achieved by implementing the magnetic current sense detection. The sensed power coil current is used in Buck and Boost control mode.

  6. The Status of Research Regarding Magnetic Mirrors as a Fusion Neutron Source or Power Plant

    SciTech Connect

    Simonen, T

    2008-12-23

    experiments have confirmed the physics of effluent plasma stabilization predicted by theory. The plasma had a mean ion energy of 10 keV and a density of 5e19m-3. If successful, the axisymmetric tandem mirror extension of the GDT idea could lead to a Q {approx} 10 power plant of modest size and would yield important applications at lower Q. In addition to the GDT method, there are four other ways to augment stability that have been demonstrated; including: plasma rotation (MCX), diverter coils (Tara), pondermotive (Phaedrus & Tara), and end wall funnel shape (Nizhni Novgorod). There are also 5 stabilization techniques predicted, but not yet demonstrated: expander kinetic pressure (KSTM-Post), Pulsed ECH Dynamic Stabilization (Post), wall stabilization (Berk), non-paraxial end mirrors (Ryutov), and cusp ends (Kesner). While these options should be examined further together with conceptual engineering designs. Physics issues that need further analysis include: electron confinement, MHD and trapped particle modes, analysis of micro stability, radial transport, evaluation and optimization of Q, and the plasma density needed to bridge to the expansion-region. While promising all should be examined through increased theory effort, university-scale experiments, and through increased international collaboration with the substantial facilities in Russia and Japan The conventional wisdom of magnetic mirrors was that they would never work as a fusion concept for a number of reasons. This conventional wisdom is most probably all wrong or not applicable, especially for applications such as low Q (DT Neutron Source) aimed at materials testing or for a Q {approx} 3-5 fusion neutron source applied to destroying actinides in fission waste and breeding of fissile fuel.

  7. Modelling and simulation of new generation powerful gyrotrons for the fusion research

    NASA Astrophysics Data System (ADS)

    Sabchevski, S.; Zhelyazkov, I.

    2007-04-01

    One of the important issues related with the cyclotron resonance heating (CRH) and current drive of fusion plasmas in thermonuclear reactors (tokamaks and stellarators) is the development of multi-megawatt class gyrotrons. There are generally three stages of the implementation of that task, notably (i) elaborating a novel generation of software tools for the physical modelling and simulation of such kind of gyrotrons, (ii) their computer aided design (CAD) and construction on the basis of the simulation's results, and finally, (iii) gyrotrons' testing in real experimental conditions. This tutorial paper concerns the first item-the development of software tools. In co-operation with the Institute for Pulsed Power and Microwave Technology at the Forschungszentrum Karlsruhe, Germany, and Centre de Recherches en Physique des Plasmas at École Polytechnique Fédérale de Lausanne, Switzerland, we work on the conceptual design of the software tools under development. The basic conclusions are that the numerical codes for gyrotrons' modelling should possess the following essential characteristics: (a) portability, (b) extensibility, (c) to be oriented toward the solution of practical problems (i.e., elaborating of computer programs that can be used in the design process), (d) to be based on self-consistent 3D physical models, which take into account the departure from axial symmetry, and (e) ability to simulate time dependent processes (electrostatic PIC simulation) alongside with a trajectory analysis (ray tracing simulation). Here, we discuss how various existing numerical codes have to be improved and implemented via the advanced programming technologies for state-of-the-art computer systems including clusters, grid, parallel platforms, and supercomputers.

  8. Lightweight High Efficiency Electric Motors for Space Applications

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.; Tyler, Tony R.; Piper, P. J.

    2011-01-01

    Lightweight high efficiency electric motors are needed across a wide range of space applications from - thrust vector actuator control for launch and flight applications to - general vehicle, base camp habitat and experiment control for various mechanisms to - robotics for various stationary and mobile space exploration missions. QM Power?s Parallel Path Magnetic Technology Motors have slowly proven themselves to be a leading motor technology in this area; winning a NASA Phase II for "Lightweight High Efficiency Electric Motors and Actuators for Low Temperature Mobility and Robotics Applications" a US Army Phase II SBIR for "Improved Robot Actuator Motors for Medical Applications", an NSF Phase II SBIR for "Novel Low-Cost Electric Motors for Variable Speed Applications" and a DOE SBIR Phase I for "High Efficiency Commercial Refrigeration Motors" Parallel Path Magnetic Technology obtains the benefits of using permanent magnets while minimizing the historical trade-offs/limitations found in conventional permanent magnet designs. The resulting devices are smaller, lower weight, lower cost and have higher efficiency than competitive permanent magnet and non-permanent magnet designs. QM Power?s motors have been extensively tested and successfully validated by multiple commercial and aerospace customers and partners as Boeing Research and Technology. Prototypes have been made between 0.1 and 10 HP. They are also in the process of scaling motors to over 100kW with their development partners. In this paper, Parallel Path Magnetic Technology Motors will be discussed; specifically addressing their higher efficiency, higher power density, lighter weight, smaller physical size, higher low end torque, wider power zone, cooler temperatures, and greater reliability with lower cost and significant environment benefit for the same peak output power compared to typically motors. A further discussion on the inherent redundancy of these motors for space applications will be provided.

  9. Advanced high efficiency wraparound contact solar cell

    NASA Technical Reports Server (NTRS)

    Scott-Monck, J. A.; Uno, F. M.; Thornhill, J. W.

    1977-01-01

    A significant advancement in the development of thin high efficiency wraparound contact silicon solar cells has been made by coupling space and terrestrial processing procedures. Although this new method for fabricating cells has not been completely reduced to practice, some of the initial cells have delivered over 20 mW/sq cm when tested at 25 C under AMO intensity. This approach not only yields high efficiency devices, but shows promise of allowing complete freedom of choice in both the location and size of the wraparound contact pad area

  10. Advanced high efficiency wraparound contact solar cell

    NASA Technical Reports Server (NTRS)

    Scott-Monck, J. A.; Uno, F. M.; Thornhill, J. W.

    1977-01-01

    A significant advancement in the development of thin high efficiency wraparound contact silicon solar cells has been made by coupling space and terrestrial processing procedures. Although this new method for fabricating cells has not been completely reduced to practice, some of the initial cells have delivered over 20 mW/sq cm when tested at 25 C under AMO intensity. This approach not only yields high efficiency devices, but shows promise of allowing complete freedom of choice in both the location and size of the wraparound contact pad area.

  11. Measure Guideline. High Efficiency Natural Gas Furnaces

    SciTech Connect

    Brand, L.; Rose, W.

    2012-10-01

    This measure guideline covers installation of high-efficiency gas furnaces, including: when to install a high-efficiency gas furnace as a retrofit measure; how to identify and address risks; and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

  12. Measure Guideline: High Efficiency Natural Gas Furnaces

    SciTech Connect

    Brand, L.; Rose, W.

    2012-10-01

    This Measure Guideline covers installation of high-efficiency gas furnaces. Topics covered include when to install a high-efficiency gas furnace as a retrofit measure, how to identify and address risks, and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

  13. Block Ignition Inertial Confinement Fusion (ICF) with Condensed Matter Cluster Type Targets for p-B11 Powered Space Propulsion

    SciTech Connect

    Miley, George H.; Hora, H.; Badziak, J.; Wolowski, J.; Sheng Zhengming; Zhang Jie; Osman, F.; Zhang Weiyan; Tuhe Xia

    2009-03-16

    The use of laser-driven Inertial Confinement Fusion (ICF) for space propulsion has been the subject of several earlier conceptual design studies, (see: Orth, 1998; and other references therein). However, these studies were based on older ICF technology using either 'direct' or 'in-direct x-ray driven' type target irradiation. Important new directions have opened for laser ICF in recent years following the development of 'chirped' lasers capable of ultra short pulses with powers of TW up to few PW which leads to the concept of 'fast ignition (FI)' to achieve higher energy gains from target implosions. In a recent publication the authors showed that use of a modified type of FI, termed 'block ignition' (Miley et al., 2008), could meet many of the requirements anticipated (but not then available) by the designs of the Vehicle for Interplanetary Space Transport Applications (VISTA) ICF fusion propulsion ship (Orth, 2008) for deep space missions. Subsequently the first author devised and presented concepts for imbedding high density condensed matter 'clusters' of deuterium into the target to obtain ultra high local fusion reaction rates (Miley, 2008). Such rates are possible due to the high density of the clusters (over an order of magnitude above cryogenic deuterium). Once compressed by the implosion, the yet higher density gives an ultra high reaction rate over the cluster volume since the fusion rate is proportional to the square of the fuel density. Most recently, a new discovery discussed here indicates that the target matrix could be composed of B{sup 11} with proton clusters imbedded. This then makes p-B{sup 11} fusion practical, assuming all of the physics issues such as stability of the clusters during compression are resolved. Indeed, p-B{sup 11} power is ideal for fusion propulsion since it has a minimum of unwanted side products while giving most of the reaction energy to energetic alpha particles which can be directed into an exhaust (propulsion) nozzle

  14. Osiris and SOMBRERO inertial confinement fusion power plant designs. Volume 2, Designs, assessments, and comparisons, Final report

    SciTech Connect

    Meier, W.R.; Bieri, R.L.; Monsler, M.J.

    1992-03-01

    The primary objective of the of the IFE Reactor Design Studies was to provide the Office of Fusion Energy with an evaluation of the potential of inertial fusion for electric power production. The term reactor studies is somewhat of a misnomer since these studies included the conceptual design and analysis of all aspects of the IFE power plants: the chambers, heat transport and power conversion systems, other balance of plant facilities, target systems (including the target production, injection, and tracking systems), and the two drivers. The scope of the IFE Reactor Design Studies was quite ambitious. The majority of our effort was spent on the conceptual design of two IFE electric power plants, one using an induction linac heavy ion beam (HIB) driver and the other using a Krypton Fluoride (KrF) laser driver. After the two point designs were developed, they were assessed in terms of their (1) environmental and safety aspects; (2) reliability, availability, and maintainability; (3) technical issues and technology development requirements; and (4) economics. Finally, we compared the design features and the results of the assessments for the two designs.

  15. High Efficient Synthesis of Iron-based Superconductors

    NASA Astrophysics Data System (ADS)

    Fang, Ai-Hua; Huang, Fu-Qiang; Xie, Xiao-Ming; Jiang, Mian-Heng

    We have performed systematic investigations aimed at high efficient synthesis of the 1111 family iron-based superconductors. By using meta-stable reactive starting materials of LnAs and FeO, assisted by mechanical alloying and fast heating, high purity samples with Tconset greater than 50K can be made with sintering temperatures between 1433K-1073K, and sintering time from 20 min to 40 h. High purity phase with sintering temperature as low as 973K was demonstrated successfully although Tconset fall below 50K and weak grain boundary suppressed greatly the zero resistance temperature. Ultra fast microwave sintering brings the sintering time further down to 5 min. Samples prepared by the above high efficient methods typically posses submicron grain and very high upper critical field, indicating very high pinning power. Besides offering cost advantages, the developed methods may play important roles in the exploit of novel superconductors.

  16. High efficiency novel window air conditioner

    SciTech Connect

    Bansal, Pradeep

    2015-01-01

    This paper presents the technical development of a high efficiency window air conditioner. In order to achieve higher energy efficiency ratio (EER), the original capacity of the R410A unit was downgraded by replacing the original compressor with a lower capacity but higher EER compressor, while all heat exchangers and the chassis from the original unit were retained. The other subsequent major modifications included – the AC fan motor being replaced with a brushless high efficiency electronically commuted motor (ECM) motor, the capillary tube being replaced with a needle valve to better control the refrigerant flow and refrigerant set points, and R410A being replaced with drop-in environmentally friendly binary mixture of R32 (85% molar concentration)/R125 (15% molar concentration). All these modifications resulted in significant EER enhancement of the modified unit.

  17. High efficiency novel window air conditioner

    DOE PAGES

    Bansal, Pradeep

    2015-01-01

    This paper presents the technical development of a high efficiency window air conditioner. In order to achieve higher energy efficiency ratio (EER), the original capacity of the R410A unit was downgraded by replacing the original compressor with a lower capacity but higher EER compressor, while all heat exchangers and the chassis from the original unit were retained. The other subsequent major modifications included – the AC fan motor being replaced with a brushless high efficiency electronically commuted motor (ECM) motor, the capillary tube being replaced with a needle valve to better control the refrigerant flow and refrigerant set points, andmore » R410A being replaced with drop-in environmentally friendly binary mixture of R32 (85% molar concentration)/R125 (15% molar concentration). All these modifications resulted in significant EER enhancement of the modified unit.« less

  18. Creation of High Efficient Firefly Luciferase

    NASA Astrophysics Data System (ADS)

    Nakatsu, Toru

    Firefly emits visible yellow-green light. The bioluminescence reaction is carried out by the enzyme luciferase. The bioluminescence of luciferase is widely used as an excellent tool for monitoring gene expression, the measurement of the amount of ATP and in vivo imaging. Recently a study of the cancer metastasis is carried out by in vivo luminescence imaging system, because luminescence imaging is less toxic and more useful for long-term assay than fluorescence imaging by GFP. However the luminescence is much dimmer than fluorescence. Then bioluminescence imaging in living organisms demands the high efficient luciferase which emits near infrared lights or enhances the emission intensity. Here I introduce an idea for creating the high efficient luciferase based on the crystal structure.

  19. High efficiency wraparound contact solar cells /HEWACS/

    NASA Technical Reports Server (NTRS)

    Gillanders, M.; Opjorden, R.

    1980-01-01

    A cell technology, producing high efficiency wrap-around contact solar cells (HEWACS), with both electrical contacts on the back and AMO conversion efficiencies of almost 15%, is presented. A flow chart indicating the baseline process sequence along with the process changes is given. Tests checking for coating delamination and contact integrity, those measuring contact strength, and thermal cycle tests, successfully demonstrated that this cell technology is ready to be moved to the pilot production stage.

  20. High-efficiency silicon solar cells

    NASA Technical Reports Server (NTRS)

    Olsen, L. C.

    1985-01-01

    Fabrication and characterization of high-efficiency metal insulator, n-p (MINP) cells is described. Particular attention was paid to development of measurement methods for surface recombination and density of surface states. A modified Rosier test structure was used successfully for density of surface states. Silicon oxide and silicon nitride passivants were studied. Heat treatment after plasma enhanced chemical vapor deposition (CVD) of silicon nitride was shown to be beneficial. A more optimum emitter concentration profile was modeled.

  1. High efficiency, long-life photocathodes

    NASA Astrophysics Data System (ADS)

    Ives, Lawrence; Montgomery, Eric; Jensen, Kevin; Collins, George; Marsden, David; Karimov, Rasul; Falce, Lou

    2017-03-01

    Research and development on high efficiency, robust, long-life photocathodes is in progress for accelerator, light source, and other commercial applications. The research is investigating detailed physics of photoemission and developing a computational capability to predict performance. Reservoir technology will significantly increase lifetime and allow recovery from many poisoning events. Better understanding of the physics will impact fabrication techniques to optimize performance. A production facility is under construction to provide improved photocathodes to users.

  2. Physics of laser fusion. Volume IV. The future development of high-power solid-state laser systems

    SciTech Connect

    Emmett, J.L.; Krupke, W.F.; Trenholme, J.B.

    1982-11-01

    Solid state lasers, particularly neodymium glass systems, have undergone intensive development during the last decade. In this paper, we review solid state laser technology in the context of high-peak-power systems for inertial confinement fusion. Specifically addressed are five major factors: efficiency, wavelength flexibility, average power, system complexity, and cost; these factors today limit broader application of the technology. We conclude that each of these factors can be greatly improved within current fundamental physical limits. We further conclude that the systematic development of new solid state laser madia, both vitreous and crystalline, should ultimately permit the development of wavelength-flexible, very high average power systems with overall efficiencies in the range of 10 to 20%.

  3. Inertial confinement fusion with direct electric generation by magnetic flux comparession

    SciTech Connect

    Lasche, G.P.

    1983-01-01

    A high-power-density laser-fusion-reactor concept in investigated in which directed kinetic enery imparted to a large mass of liquid lithium--in which the fusion target is centrally located--is maximized. In turn, this kinetic energy is converted directly to electricity with, potentially, very high efficiency by work done against a pulsed magnetic field applied exterior to the lithium. Because the concept maximizes the blanket thickness per unit volume of lithium, neutron-induced radioactivities in the reaction chamber wall can be many orders of magnitude less than is typical of D-T fusion reactor concepts.

  4. Use of Clearance Indexes to Assess Waste Disposal Issues for the HYLIFE-II Inertial Fusion Energy Power Plant Design

    SciTech Connect

    Reyes, S; Latkowski, J F; Sanz, J

    2002-01-17

    Traditionally, waste management studies for fusion energy have used the Waste Disposal Rating (WDR) to evaluate if radioactive material from irradiated structures could qualify for shallow land burial. However, given the space limitations and the negative public perception of large volumes of waste, there is a growing international motivation to develop a fusion waste management system that maximizes the amount of material that can be cleared or recycled. In this work, we present an updated assessment of the waste management options for the HYLIFE-II inertial fusion energy (IFE) power plant, using the concept of Clearance Index (CI) for radioactive waste disposal. With that purpose, we have performed a detailed neutronics analysis of the HYLIFE-II design, using the TART and ACAB computer codes for neutron transport and activation, respectively. Whereas the traditional version of ACAB only provided the user with the WDR as an index for waste considerations, here we have modified the code to calculate Clearance Indexes using the current International Atomic Energy Agency (IAEA) clearance limits for radiological waste disposal. The results from the analysis are used to perform an assessment of the waste management options for the HYLIFE-II IFE design.

  5. Method and system to directly produce electrical power within the lithium blanket region of a magnetically confined, deuterium-tritium (DT) fueled, thermonuclear fusion reactor

    DOEpatents

    Woolley, Robert D.

    1999-01-01

    A method for integrating liquid metal magnetohydrodynamic power generation with fusion blanket technology to produce electrical power from a thermonuclear fusion reactor located within a confining magnetic field and within a toroidal structure. A hot liquid metal flows from a liquid metal blanket region into a pump duct of an electromagnetic pump which moves the liquid metal to a mixer where a gas of predetermined pressure is mixed with the pressurized liquid metal to form a Froth mixture. Electrical power is generated by flowing the Froth mixture between electrodes in a generator duct. When the Froth mixture exits the generator the gas is separated from the liquid metal and both are recycled.

  6. Method and System to Directly Produce Electrical Power within the Lithium Blanket Region of a Magnetically Confined, Deuterium-Tritium (DT) Fueled, Thermonuclear Fusion Reactor

    SciTech Connect

    Woolley, Robert D.

    1998-09-22

    A method for integrating liquid metal magnetohydrodynamic power generation with fusion blanket technology to produce electrical power from a thermonuclear fusion reactor located within a confining magnetic field and within a toroidal structure. A hot liquid metal flows from a liquid metal blanket region into a pump duct of an electromagnetic pump which moves the liquid metal to a mixer where a gas of predetermined pressure is mixed with the pressurized liquid metal to form a Froth mixture. Electrical power is generated by flowing the Froth mixture between electrodes in a generator duct. When the Froth mixture exits the generator the gas is separated from the liquid metal and both are recycled.

  7. High Efficiency Solar Integrated Roof Membrane Product

    SciTech Connect

    Partyka, Eric; Shenoy, Anil

    2013-05-15

    This project was designed to address the Solar Energy Technology Program objective, to develop new methods to integrate photovoltaic (PV) cells or modules within a building-integrated photovoltaic (BIPV) application that will result in lower installed cost as well as higher efficiencies of the encapsulated/embedded PV module. The technology assessment and development focused on the evaluation and identification of manufacturing technologies and equipment capable of producing such low-cost, high-efficiency, flexible BIPV solar cells on single-ply roofing membranes.

  8. Very High Efficiency Solar Cell Modules

    SciTech Connect

    Barnett, A.; Kirkpatrick, D.; Honsberg, C.; Moore, D.; Wanlass, M.; Emery, K.; Schwartz, R.; Carlson, D.; Bowden, S.; Aiken, D.; Gray, A.; Kurtz, S.; Kazmerski, L., et al

    2009-01-01

    The Very High Efficiency Solar Cell (VHESC) program is developing integrated optical system - PV modules for portable applications that operate at greater than 50% efficiency. We are integrating the optical design with the solar cell design, and have entered previously unoccupied design space. Our approach is driven by proven quantitative models for the solar cell design, the optical design, and the integration of these designs. Optical systems efficiency with an optical efficiency of 93% and solar cell device results under ideal dichroic splitting optics summing to 42.7 {+-} 2.5% are described.

  9. Proposal for superstructure based high efficiency photovoltaics

    NASA Technical Reports Server (NTRS)

    Wagner, M.; Leburton, J. P.

    1986-01-01

    A novel class of cascade structures is proposed which features multijunction upper subcells, referred to as superstructure high-efficiency photovoltaics (SHEPs). The additional junctions enhance spectral response and improve radiation tolerance by reducing bulk recombination losses. This is important because ternary III-V alloys, which tend to have short minority-carrier diffusion lengths, are the only viable materials for the high-bandgap upper subcells required for cascade solar cells. Realistic simulations of AlGaAs SHEPs show that one-sun AM0 efficiencies in excess of 26 percent are possible.

  10. High-Efficiency Absorber for Damping the Transverse Wake Fields

    SciTech Connect

    Novokhatski, A.; Seeman, J.; Weathersby, S.; /SLAC

    2007-02-28

    Transverse wake fields generated by intense beams may propagate long distances in the vacuum chamber and dissipate power in different shielded elements such as bellows, vacuum valves or vacuum pumps. Induced heating in these elements may be high enough to deteriorate vacuum conditions. We have developed a broadband water-cooled bellows-absorber to capture and damp these harmful transverse fields without impacting the longitudinal beam impedance. Experimental results at the PEP-II SLAC B-factory demonstrate high efficiency of this device. This absorber may be useful in other machines like synchrotron light sources or International Linear Collider.

  11. High efficiency low cost monolithic module for SARSAT distress beacons

    NASA Technical Reports Server (NTRS)

    Petersen, Wendell C.; Siu, Daniel P.

    1992-01-01

    The program objectives were to develop a highly efficient, low cost RF module for SARSAT beacons; achieve significantly lower battery current drain, amount of heat generated, and size of battery required; utilize MMIC technology to improve efficiency, reliability, packaging, and cost; and provide a technology database for GaAs based UHF RF circuit architectures. Presented in viewgraph form are functional block diagrams of the SARSAT distress beacon and beacon RF module as well as performance goals, schematic diagrams, predicted performances, and measured performances for the phase modulator and power amplifier.

  12. High-efficiency, 200 watt, 12-gigahertz traveling wave tube

    NASA Technical Reports Server (NTRS)

    Kosmahl, H. G.; Mcnary, B. D.; Sauseng, O.

    1974-01-01

    Design and performance of a highly efficient experimental 200-watt traveling wave tube for space communications are described. The tube uses a coupled cavity slow wave structure with periodic permanent magnet focusing. A two-step velocity taper is incorporated in the slow wave structure for velocity resynchronization with the modulated beam. The spent beam is reconditioned in a refocusing section before it is collected in a novel multistage depressed collector. The collector is radiation cooled and heat insulated from the tube body. At saturation the tube provides peak output power of 240 watts with a 35-db gain and an overall maximum efficiency of 56 percent.

  13. Resonantly pumped high efficiency Ho:YAG laser.

    PubMed

    Shen, Ying-Jie; Yao, Bao-Quan; Duan, Xiao-Ming; Dai, Tong-Yu; Ju, You-Lun; Wang, Yue-Zhu

    2012-11-20

    High-efficient CW and Q-switched Ho:YAG lasers resonantly dual-end-pumped by two diode-pumped Tm:YLF lasers at 1908 nm were investigated. A maximum slope efficiency of 74.8% in CW operation as well as a maximum output power of 58.7 W at 83.2 W incident pump power was achieved, which corresponded to an optical-to-optical conversion efficiency of 70.6%. The maximum pulse energy of 2.94 mJ was achieved, with a 31 ns FWHM pulse width and a peak power of approximately 94.7 kW.

  14. Highly efficient one-dimensional ZnO nanowire-based dye-sensitized solar cell using a metal-free, D-π-A-type, carbazole derivative with more than 5% power conversion.

    PubMed

    Barpuzary, Dipankar; Patra, Anindya S; Vaghasiya, Jayraj V; Solanki, Bharat G; Soni, Saurabh S; Qureshi, Mohammad

    2014-08-13

    Hydrothermally grown one-dimensional ZnO nanowire (1D ZnO NW) and a newly synthesized metal-free, D-π-A type, carbazole dye (SK1) sensitizer-based photovoltaic device with a power conversion efficiency (PCE) of more than 5% have been demonstrated by employing the cobalt tris(2,2'-bipyridyl) redox shuttle. A short-circuit current density (Jsc) of ∼12.0 mA/cm(2), an open-circuit voltage (Voc) of ∼719 mV, and a fill factor (FF) of ∼65% have been afforded by the 1D ZnO NW-based dye-sensitized solar cell (DSSC) incorporating [Co(bpy)3](3+/2+) complex as the one-electron redox mediator. In contrast, the identical DSSC with traditional I3(-)/I(-) electrolyte has shown a Jsc ≈ 12.2 mA/cm(2), a Voc ≈ 629 mV, and a FF ≈ 62%, yielding a PCE of ∼4.7%. The persuasive role of the inherent superior electron transport property of 1D ZnO NWs in enhancing the device efficiency is evidenced from the impoverished performance of the DSSCs with photoanodes fabricated using ZnO nanoparticles (NPs). The DSSCs having ZnO NP-based photoanodes have achieved the PCEs of ∼3.6% and ∼3.2% using cobalt- and iodine-based redox electrolytes, respectively. The electronic interactions between the SK1 sensitizer and ZnO (NWs and NPs) to induce the photogenerated charge transfer from SK1 to the conduction band (CB) of ZnO are evidenced from the significant quenching of photoluminescence and exciton lifetime decay of SK1, when it is anchored onto the ZnO architectures. The energetics of the SK1 dye molecule are estimated by combining the spectroscopic and electrochemical techniques. The electronic distributions of SK1 dye molecule in its HOMO and LUMO energy levels are interpreted using density functional theory (DFT)-based calculations. The electron donor-π linker-acceptor (D-π-A) configuration of SK1 dye provides an intramolecular charge transfer within the molecule, prompting the electron migration from the carbazole donor to cyanoacrylic acceptor moiety via the oligo

  15. High Efficiency, Illumination Quality OLEDs for Lighting

    SciTech Connect

    Joseph Shiang; James Cella; Kelly Chichak; Anil Duggal; Kevin Janora; Chris Heller; Gautam Parthasarathy; Jeffery Youmans; Joseph Shiang

    2008-03-31

    2003, a large area, OLED based illumination source was demonstrated that could provide light with a quality, quantity, and efficiency on par with what can be achieved with traditional light sources. The demonstration source was made by tiling together 16 separate 6-inch x 6-inch blue-emitting OLEDs. The efficiency, total lumen output, and lifetime of the OLED based illumination source were the same as what would be achieved with an 80 watt incandescent bulb. The devices had an average efficacy of 15 LPW and used solution-processed OLEDs. The individual 6-inch x 6-inch devices incorporated three technology strategies developed specifically for OLED lighting -- downconversion for white light generation, scattering for outcoupling efficiency enhancement, and a scalable monolithic series architecture to enable large area devices. The downconversion approach consists of optically coupling a blue-emitting OLED to a set of luminescent layers. The layers are chosen to absorb the blue OLED emission and then luminescence with high efficiency at longer wavelengths. The composition and number of layers are chosen so that the unabsorbed blue emission and the longer wavelength re-emission combine to make white light. A downconversion approach has the advantage of allowing a wide variety of colors to be made from a limited set of blue emitters. In addition, one does not have to carefully tune the emission wavelength of the individual electro-luminescent species within the OLED device in order to achieve white light. The downconversion architecture used to develop the 15LPW large area light source consisted of a polymer-based blue-emitting OLED and three downconversion layers. Two of the layers utilized perylene based dyes from BASF AG of Germany with high quantum efficiency (>98%) and one of the layers consisted of inorganic phosphor particles (Y(Gd)AG:Ce) with a quantum efficiency of {approx}85%. By independently varying the optical density of the downconversion layers, the overall

  16. CRISPRscan: designing highly efficient sgRNAs for CRISPR/Cas9 targeting in vivo

    PubMed Central

    Moreno-Mateos, Miguel A.; Vejnar, Charles E.; Beaudoin, Jean-Denis; Fernandez, Juan P.; Mis, Emily K.; Khokha, Mustafa K.; Giraldez, Antonio J.

    2015-01-01

    CRISPR/Cas9 technology provides a powerful system for genome engineering. However, variable activity across different single guide RNAs (sgRNAs) remains a significant limitation. We have analyzed the molecular features that influence sgRNA stability, activity and loading into Cas9 in vivo. We observe that guanine enrichment and adenine depletion increase sgRNA stability and activity, while loading, nucleosome positioning and Cas9 off-target binding are not major determinants. We additionally identified truncated and 5′ mismatch-containing sgRNAs as efficient alternatives to canonical sgRNAs. Based on these results, we created a predictive sgRNA-scoring algorithm (CRISPRscan.org) that effectively captures the sequence features affecting Cas9/sgRNA activity in vivo. Finally, we show that targeting Cas9 to the germ line using a Cas9-nanos-3′-UTR fusion can generate maternal-zygotic mutants, increase viability and reduce somatic mutations. Together, these results provide novel insights into the determinants that influence Cas9 activity and a framework to identify highly efficient sgRNAs for genome targeting in vivo. PMID:26322839

  17. High efficiency electrotransformation of Lactobacillus casei.

    PubMed

    Welker, Dennis L; Hughes, Joanne E; Steele, James L; Broadbent, Jeff R

    2015-01-01

    We investigated whether protocols allowing high efficiency electrotransformation of other lactic acid bacteria were applicable to five strains of Lactobacillus casei (12A, 32G, A2-362, ATCC 334 and BL23). Addition of 1% glycine or 0.9 M NaCl during cell growth, limitation of the growth of the cell cultures to OD600 0.6-0.8, pre-electroporation treatment of cells with water or with a lithium acetate (100 mM)/dithiothreitol (10 mM) solution and optimization of electroporation conditions all improved transformation efficiencies. However, the five strains varied in their responses to these treatments. Transformation efficiencies of 10(6) colony forming units μg(-1) pTRKH2 DNA and higher were obtained with three strains which is sufficient for construction of chromosomal gene knock-outs and gene replacements.

  18. A simple, high efficiency, high resolution spectropolarimeter

    NASA Astrophysics Data System (ADS)

    Barden, Samuel C.

    2012-09-01

    A simple concept is described that uses volume phase holographic gratings as polarizing dispersers for a high efficiency, high resolution spectropolarimeter. Although the idea has previously been mentioned in the literature as possible, such a concept has not been explored in detail. Performance analysis is presented for a VPHG spectropolarimeter concept that could be utilized for both solar and night-time astronomy. Instrumental peak efficiency can approach 100% with spectral dispersions permitting R~200,000 spectral resolution with diffraction limited telescopes. The instrument has 3-channels: two dispersed image planes with orthogonal polarization and an undispersed image plane. The concept has a range of versatility where it could be configured (with appropriate half-wave plates) for slit-fed spectroscopy or without slits for snapshot/hyperspectral/tomographic spectroscopic imaging. Multiplex gratings could also be used for the simultaneous recording of two separate spectral bands or multiple instruments could be daisy chained with beam splitters for further spectral coverage.

  19. High-efficiency silicon solar cells

    NASA Technical Reports Server (NTRS)

    Green, M. A.; Blakers, A. W.; Shi, J.; Keller, E. M.; Wenham, S. R.

    1984-01-01

    Silicon solar cells are described which operate at energy conversion efficiencies independently measured at 18.7 percent under standard terrestrial test conditions (AM1.5, 100 mW/sq cm, 28 C). These are apparently the most efficient silicon cells fabricated to date. The high-efficiency results from a combination of high open-circuit voltage due to the careful attention paid to the passivation of the top surface of the cell, high fill factor due to the high open-circuit voltage and low parasitic resistance losses, and high short-circuit current density due to the use of shallow diffusions, a low grid coverage, and an optimized double layer antireflection coating.

  20. High Efficiency, Low Emission Refrigeration System

    SciTech Connect

    Fricke, Brian A.; Sharma, Vishaldeep

    2016-08-01

    Supermarket refrigeration systems account for approximately 50% of supermarket energy use, placing this class of equipment among the highest energy consumers in the commercial building domain. In addition, the commonly used refrigeration system in supermarket applications is the multiplex direct expansion (DX) system, which is prone to refrigerant leaks due to its long lengths of refrigerant piping. This leakage reduces the efficiency of the system and increases the impact of the system on the environment. The high Global Warming Potential (GWP) of the hydrofluorocarbon (HFC) refrigerants commonly used in these systems, coupled with the large refrigerant charge and the high refrigerant leakage rates leads to significant direct emissions of greenhouse gases into the atmosphere. Methods for reducing refrigerant leakage and energy consumption are available, but underutilized. Further work needs to be done to reduce costs of advanced system designs to improve market utilization. In addition, refrigeration system retrofits that result in reduced energy consumption are needed since the majority of applications address retrofits rather than new stores. The retrofit market is also of most concern since it involves large-volume refrigerant systems with high leak rates. Finally, alternative refrigerants for new and retrofit applications are needed to reduce emissions and reduce the impact on the environment. The objective of this Collaborative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory and Hill Phoenix is to develop a supermarket refrigeration system that reduces greenhouse gas emissions and has 25 to 30 percent lower energy consumption than existing systems. The outcomes of this project will include the design of a low emission, high efficiency commercial refrigeration system suitable for use in current U.S. supermarkets. In addition, a prototype low emission, high efficiency supermarket refrigeration system will be produced for

  1. High efficiency, multiterawatt x-ray free electron lasers

    NASA Astrophysics Data System (ADS)

    Emma, C.; Fang, K.; Wu, J.; Pellegrini, C.

    2016-02-01

    In this paper we present undulator magnet tapering methods for obtaining high efficiency and multiterawatt peak powers in x-ray free electron lasers (XFELs), a key requirement for enabling 3D atomic resolution single molecule imaging and nonlinear x-ray science. The peak power and efficiency of tapered XFELs is sensitive to time dependent effects, like synchrotron sideband growth. To analyze this dependence in detail we perform a comparative numerical optimization for the undulator magnetic field tapering profile including and intentionally disabling these effects. We show that the solution for the magnetic field taper profile obtained from time independent optimization does not yield the highest extraction efficiency when time dependent effects are included. Our comparative optimization is performed for a novel undulator designed specifically to obtain TW power x-ray pulses in the shortest distance: superconducting, helical, with short period and built-in strong focusing. This design reduces the length of the breaks between modules, decreasing diffraction effects, and allows using a stronger transverse electron focusing. Both effects reduce the gain length and the overall undulator length. We determine that after a fully time dependent optimization of a 100 m long Linac coherent light source-like XFEL we can obtain a maximum efficiency of 7%, corresponding to 3.7 TW peak radiation power. Possible methods to suppress the synchrotron sidebands, and further enhance the FEL peak power, up to about 6 TW by increasing the seed power and reducing the electron beam energy spread, are also discussed.

  2. Materials recycle and waste management in fusion power reactors. Progress report for 1982

    SciTech Connect

    Vogler, S.; Jung, J.; Steindler, M.J.; Maya, I.; Levine, H.E.; Peterman, D.D.; Strausburg, S.; Schultz, K.R.

    1983-01-01

    Several components of a STARFIRE fusion reactor have been studied. The breeding ratios were calculated as a function of lithium enrichment and neutron multiplier for systems containing either Li/sub 2/O or LiAlO/sub 2/. The lithium requirements for a fusion economy were also estimated for those cases and the current US resources were found to be adequate. However, competition with other lithium demands in the future emphasizes the need for recovering and reusing lithium. The radioactivities induced in the breeder and the impurities responsible for their formation were determined. The residual radioactivities of several low-activation structural materials were compared with the radioactivity from the prime candidate alloy (PCA) a titanium modified Type 316 stainless steel used in STARFIRE. The impurities responsible for the radioactivity levels were identified. From these radioactive impurity levels it was determined that V15Cr5Ti could meet the requirements for shallow land burial as specified by the Nuclear Regulatory Commission (10CFR61), whereas PCA would require a more restrictive disposal mode, i.e. in a geologic medium. The costs for each of these disposal modes were then estimated.

  3. A high-efficiency heat-pump fan

    NASA Astrophysics Data System (ADS)

    Wright, T.; Lackey, R. S.; Veyo, S. E.

    1983-06-01

    Efforts toward development of a high-efficiency outdoor air mover for an advanced electric heat pump are documented. The design goal was to halve the outdoor air-moving electrical power. The prototype air mover at 850 rpm delivers 3070 scfm through the prototype outdoor unit with a pressure drop through the coil of 0.09 inches of water and consumes 150 watts of electrical power. The overall air-moving efficiency is estimated at about 35 percent compared with 19 percent for the conventionally-applied heat pump fan. Although this air mover will cost twice as much as the conventional heat pump air mover, this premium cost should be recoverable in less than four years through energy savings. The sound rating (SFN) for this air mover is less than 20. Means for improving fan efficiency by 5 percentage points, motor efficiency by 2.5 points, and to further quiet the fan were identified.

  4. Current Trends of Blanket Research and Deveopment in Japan 2.Roles and Requirements of the Blanket System of Fusion Power Reactors

    NASA Astrophysics Data System (ADS)

    Asaoka, Yoshiyuki; Mohri, Kensuke; Hashizume, Hidetoshi; Tanaka, Satoru; Ueda, Yoshio

    Roles and requirements of the blanket system of the fusion power reactors are discussed from viewpoints of economics, fuel supply, generation system, maintenance, radioactive waste, and interaction with the plasma core. As the blanket system influences the cost of the fusion energy, the blanket system must be designed to minimize the fusion energy cost. Tritium breeding performance of the blanket is indispensable role to show the advantage of fusion energy on energy security. Material development for high temperature use under high neutron flux is one of the key issues of the generation system because the thermal efficiency depends on the coolant temperature of the blanket. Innovative maintenance technologies such as dividable superconducting coil system are very effective to make the fusion power reactor attractive. From viewpoints of natural resources and waste management, materials used in the fusion reactors should be recycled. Material selection is also of a large importance on the cost of radioactive waste disposal. Finally, it must be paid a careful attention that the design of the blanket system is inseparable from the achievement of a high performance plasma core.

  5. Energy payback and CO{sub 2} gas emissions from fusion and solar photovoltaic electric power plants. Final report to Department of Energy, Office of Fusion Energy Sciences

    SciTech Connect

    Kulcinski, G.L.

    2002-12-01

    A cradle-to-grave net energy and greenhouse gas emissions analysis of a modern photovoltaic facility that produces electricity has been performed and compared to a similar analysis on fusion. A summary of the work has been included in a Ph.D. thesis titled ''Life-cycle assessment of electricity generation systems and applications for climate change policy analysis'' by Paul J. Meier, and a synopsis of the work was presented at the 15th Topical meeting on Fusion Energy held in Washington, DC in November 2002. In addition, a technical note on the effect of the introduction of fusion energy on the greenhouse gas emissions in the United States was submitted to the Office of Fusion Energy Sciences (OFES).

  6. High Efficiency Octave Bandwidth Millimeter Wave Power Amplifier

    DTIC Science & Technology

    1989-08-01

    OECLASSIFICATIONI DOWNGRADING SCHEDULE No Restrictions 4. PERFORMING ORGANIZATION REPORT NUMBER(S) 5. MONITORING ORGANIZATION REPORT NUMBER(S) 6a. NAME OF...PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION (If applicable) oneywell Systems and Research Ŗ I Center _Office of-Naval...55420 Arlington, VA 22217-5000 8a. NAME OF FUNDING/SPONSORING 8b. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION (If

  7. High efficiency thermoelectric power generation using Zintl-type materials

    NASA Technical Reports Server (NTRS)

    Snyder, G. Jeffrey (Inventor); Gascoin, Franck (Inventor); Brown, Shawna (Inventor); Kauzlarich, Susan (Inventor)

    2010-01-01

    The invention disclosed herein relates to thermoelectrically-active p-type Zintl phase materials as well as devices utilizing such compounds. Such thermoelectric materials and devices may be used to convert thermal energy into electrical energy, or use electrical energy to produce heat or refrigeration. Embodiments of the invention relate to p-type thermoelectric materials related to the compound Yb.sub.14MnSb.sub.11.

  8. Metal-Semiconductor Nanocomposites for High Efficiency Thermoelectric Power Generation

    DTIC Science & Technology

    2013-12-07

    the modified phonon and alloy scattering parameters in the modeling to explain the thermoelectric properties of this material. For example, we...near future. 2. Cross-plane thermoelectric properties of perovskite oxide metal/semiconductor superlattices ( Purdue /UCSC) The cross-plane...It therefore became critical that Purdue optimize this characterization technique to extract material properties which show the potential of metal

  9. Fusion energy for space: Feasibility demonstration. A proposal to NASA

    SciTech Connect

    Schulze, N.R.

    1992-10-01

    This proposed program is to initiate a space flight research and development program to develop fusion energy for the space applications of direct space propulsion and direct space power, that is, a Space Fusion Energy (SFE) program. 'Direct propulsion' refers to the use of plasma energy directly for thrust without requiring other energy conversion systems. Further, to provide space missions with large electrical power, 'direct space power' is proposed whereby the direct conversion of charged particles into electricity is used, thereby avoiding thermal conversion system losses. The energy release from nuclear fusion reactions makes these highly efficient, high power space systems possible. The program as presented conducts in an orderly, hierarchical manner the necessary planning, analyses, and testing to demonstrate the practical use of fusion energy for space. There is nothing discussed that is known to be theoretically impossible. Validation of the engineering principles is sought in this program which uses a cost-benefit approach. Upon successful program completion, space will become more accessible and space missions more safely conducted. The country will have taken a giant step toward the commercialization of space. The mission enabling capability provided by fusion energy is well beyond mission planners' current dreams.

  10. Fusion energy for space: Feasibility demonstration. A proposal to NASA

    NASA Technical Reports Server (NTRS)

    Schulze, Norman R.

    1992-01-01

    This proposed program is to initiate a space flight research and development program to develop fusion energy for the space applications of direct space propulsion and direct space power, that is, a Space Fusion Energy (SFE) program. 'Direct propulsion' refers to the use of plasma energy directly for thrust without requiring other energy conversion systems. Further, to provide space missions with large electrical power, 'direct space power' is proposed whereby the direct conversion of charged particles into electricity is used, thereby avoiding thermal conversion system losses. The energy release from nuclear fusion reactions makes these highly efficient, high power space systems possible. The program as presented conducts in an orderly, hierarchical manner the necessary planning, analyses, and testing to demonstrate the practical use of fusion energy for space. There is nothing discussed that is known to be theoretically impossible. Validation of the engineering principles is sought in this program which uses a cost-benefit approach. Upon successful program completion, space will become more accessible and space missions more safely conducted. The country will have taken a giant step toward the commercialization of space. The mission enabling capability provided by fusion energy is well beyond mission planners' current dreams.

  11. Bioblendstocks that Enable High Efficiency Engine Designs

    SciTech Connect

    McCormick, Robert L.; Fioroni, Gina M.; Ratcliff, Matthew A.; Zigler, Bradley T.; Farrell, John

    2016-11-03

    The past decade has seen a high level of innovation in production of biofuels from sugar, lipid, and lignocellulose feedstocks. As discussed in several talks at this workshop, ethanol blends in the E25 to E50 range could enable more highly efficient spark-ignited (SI) engines. This is because of their knock resistance properties that include not only high research octane number (RON), but also charge cooling from high heat of vaporization, and high flame speed. Emerging alcohol fuels such as isobutanol or mixed alcohols have desirable properties such as reduced gasoline blend vapor pressure, but also have lower RON than ethanol. These fuels may be able to achieve the same knock resistance benefits, but likely will require higher blend levels or higher RON hydrocarbon blendstocks. A group of very high RON (>150) oxygenates such as dimethyl furan, methyl anisole, and related compounds are also produced from biomass. While providing no increase in charge cooling, their very high octane numbers may provide adequate knock resistance for future highly efficient SI engines. Given this range of options for highly knock resistant fuels there appears to be a critical need for a fuel knock resistance metric that includes effects of octane number, heat of vaporization, and potentially flame speed. Emerging diesel fuels include highly branched long-chain alkanes from hydroprocessing of fats and oils, as well as sugar-derived terpenoids. These have relatively high cetane number (CN), which may have some benefits in designing more efficient CI engines. Fast pyrolysis of biomass can produce diesel boiling range streams that are high in aromatic, oxygen and acid contents. Hydroprocessing can be applied to remove oxygen and consequently reduce acidity, however there are strong economic incentives to leave up to 2 wt% oxygen in the product. This oxygen will primarily be present as low CN alkyl phenols and aryl ethers. While these have high heating value, their presence in diesel fuel

  12. Phenomena and Performance of High-Efficiency Split Spectrum Photovoltaics

    NASA Astrophysics Data System (ADS)

    Downs, Chandler

    High-efficiency photovoltaics are one of the most promising technologies for supplying sustainable energy in the near future. These technologies allow for high energy conversion efficiencies and long system lifetimes, which is becoming an increasingly profitable power generation option. One high-efficiency photovoltaic technology gaining increasing attention recent years is that of split-spectrum photovoltaics. This technology divides the incident solar spectrum on the basis of wavelength, directing each portion of the spectrum to a different cell where the light can be utilized most efficiently. In this dissertation, a number of aspects of high-efficiency photovoltaics, most notably split-spectrum photovoltaics, are examined. First, the ideal bandgap placements of the subcells of a split-spectrum photovoltaic system are calculated, specifically determined with an eye towards practical fabrication of the cells. Two viable designs are determined which improve theoretical absolute conversion efficiency by 4-5%. Next, those systems are simulated using the TCAD Sentaurus software package to project conversion efficiencies and determine additional device specifications (doping levels, layer thicknesses, etc.). These cells show comparable conversion efficiencies to high performing, full-spectrum multijunction photovoltaics in fabrication today. In the last section, a theoretical examination of semiconductor performance under high optical concentration is performed, including the prediction and characterization of various phenomena in those devices. This work aims to improve the understanding of the performance of high concentration photovoltaics, most notably split-spectrum photovoltaics. This understanding will aid in the advancement of this technology as a widespread, sustainable energy source for use worldwide, reducing greenhouse emissions and providing cheap, clean energy.

  13. High-efficiency generation in a short random fiber laser

    NASA Astrophysics Data System (ADS)

    Vatnik, I. D.; Churkin, D. V.; Podivilov, E. V.; Babin, S. A.

    2014-07-01

    We demonstrate a high-efficiency random lasing in a 850 m span of a phosphosilicate fiber. Random distributed feedback owing to the Rayleigh backscattering in the fiber enables narrowband generation with output power of up to 7.3 W at the Stokes wavelength λS = 1308 nm from 11 W of the pump power at λP = 1115 nm. The laser demonstrates unique generation efficiency. Near the generation threshold, more than 2 W of output power is generated from only 0.5 W of pump power excess over the generation threshold. At high pump power, the quantum conversion efficiency defined as a ratio of generated and pump photons at the laser output exceeds 100%. It is explained by the fact that every pump photon is converted into the Stokes photon far from the output fiber end, while the Stokes photons have lower attenuation than the pump photons.

  14. Neutronic design studies of a conceptual DCLL fusion reactor for a DEMO and a commercial power plant

    NASA Astrophysics Data System (ADS)

    Palermo, I.; Veredas, G.; Gómez-Ros, J. M.; Sanz, J.; Ibarra, A.

    2016-01-01

    Neutronic analyses or, more widely, nuclear analyses have been performed for the development of a dual-coolant He/LiPb (DCLL) conceptual design reactor. A detailed three-dimensional (3D) model has been examined and optimized. The design is based on the plasma parameters and functional materials of the power plant conceptual studies (PPCS) model C. The initial radial-build for the detailed model has been determined according to the dimensions established in a previous work on an equivalent simplified homogenized reactor model. For optimization purposes, the initial specifications established over the simplified model have been refined on the detailed 3D design, modifying material and dimension of breeding blanket, shield and vacuum vessel in order to fulfil the priority requirements of a fusion reactor in terms of the fundamental neutronic responses. Tritium breeding ratio, energy multiplication factor, radiation limits in the TF coils, helium production and displacements per atom (dpa) have been calculated in order to demonstrate the functionality and viability of the reactor design in guaranteeing tritium self-sufficiency, power efficiency, plasma confinement, and re-weldability and structural integrity of the components. The paper describes the neutronic design improvements of the DCLL reactor, obtaining results for both DEMO and power plant operational scenarios.

  15. Experimental results of a sheet-beam, high power, FEL amplifier with application to magnetic fusion research

    SciTech Connect

    Cheng, S.; Destler, W.W.; Granatstein, V.L.

    1995-12-31

    The experimental study of sheet-beam FELs as candidate millimeter-wave sources for heating magnetic fusion plasmas has achieved a major milestone. In a proof-of-principle, pulsed experiment, saturated FEL amplifier operation was achieved with 250 kW of output power at 86 GHz. Input microwave power was 1 kW, beam voltage was 450 kV and beam current was 17 A. The planar wiggler had a peak value of 3.8 kG, a period of 0.96 cm and was 71 cm long. The linear gain of 30 dB, saturated gain of 24 dB and saturated efficiency of 3% all are in good agreement with theoretical prediction. Follow-on work would include development of a thermionic sheet-beam electron-gun compatible with CW FEL operation, adding a section of tapered wiggler to increase the output power to levels in excess of 1 megawatt, and increasing the FEL frequency.

  16. A high-efficiency aerothermoelastic analysis method

    NASA Astrophysics Data System (ADS)

    Wan, ZhiQiang; Wang, YaoKun; Liu, YunZhen; Yang, Chao

    2014-06-01

    In this paper, a high-efficiency aerothermoelastic analysis method based on unified hypersonic lifting surface theory is established. The method adopts a two-way coupling form that couples the structure, aerodynamic force, and aerodynamic thermo and heat conduction. The aerodynamic force is first calculated based on unified hypersonic lifting surface theory, and then the Eckert reference temperature method is used to solve the temperature field, where the transient heat conduction is solved using Fourier's law, and the modal method is used for the aeroelastic correction. Finally, flutter is analyzed based on the p-k method. The aerothermoelastic behavior of a typical hypersonic low-aspect ratio wing is then analyzed, and the results indicate the following: (1) the combined effects of the aerodynamic load and thermal load both deform the wing, which would increase if the flexibility, size, and flight time of the hypersonic aircraft increase; (2) the effect of heat accumulation should be noted, and therefore, the trajectory parameters should be considered in the design of hypersonic flight vehicles to avoid hazardous conditions, such as flutter.

  17. High efficiency diffusion molecular retention tumor targeting.

    PubMed

    Guo, Yanyan; Yuan, Hushan; Cho, Hoonsung; Kuruppu, Darshini; Jokivarsi, Kimmo; Agarwal, Aayush; Shah, Khalid; Josephson, Lee

    2013-01-01

    Here we introduce diffusion molecular retention (DMR) tumor targeting, a technique that employs PEG-fluorochrome shielded probes that, after a peritumoral (PT) injection, undergo slow vascular uptake and extensive interstitial diffusion, with tumor retention only through integrin molecular recognition. To demonstrate DMR, RGD (integrin binding) and RAD (control) probes were synthesized bearing DOTA (for (111) In(3+)), a NIR fluorochrome, and 5 kDa PEG that endows probes with a protein-like volume of 25 kDa and decreases non-specific interactions. With a GFP-BT-20 breast carcinoma model, tumor targeting by the DMR or i.v. methods was assessed by surface fluorescence, biodistribution of [(111)In] RGD and [(111)In] RAD probes, and whole animal SPECT. After a PT injection, both probes rapidly diffused through the normal and tumor interstitium, with retention of the RGD probe due to integrin interactions. With PT injection and the [(111)In] RGD probe, SPECT indicated a highly tumor specific uptake at 24 h post injection, with 352%ID/g tumor obtained by DMR (vs 4.14%ID/g by i.v.). The high efficiency molecular targeting of DMR employed low probe doses (e.g. 25 ng as RGD peptide), which minimizes toxicity risks and facilitates clinical translation. DMR applications include the delivery of fluorochromes for intraoperative tumor margin delineation, the delivery of radioisotopes (e.g. toxic, short range alpha emitters) for radiotherapy, or the delivery of photosensitizers to tumors accessible to light.

  18. High efficiency, variable geometry, centrifugal cryogenic pump

    SciTech Connect

    Forsha, M.D.; Nichols, K.E.; Beale, C.A.

    1994-12-31

    A centrifugal cryogenic pump has been developed which has a basic design that is rugged and reliable with variable speed and variable geometry features that achieve high pump efficiency over a wide range of head-flow conditions. The pump uses a sealless design and rolling element bearings to achieve high reliability and the ruggedness to withstand liquid-vapor slugging. The pump can meet a wide range of variable head, off-design flow requirements and maintain design point efficiency by adjusting the pump speed. The pump also has features that allow the impeller and diffuser blade heights to be adjusted. The adjustable height blades were intended to enhance the pump efficiency when it is operating at constant head, off-design flow rates. For small pumps, the adjustable height blades are not recommended. For larger pumps, they could provide off-design efficiency improvements. This pump was developed for supercritical helium service, but the design is well suited to any cryogenic application where high efficiency is required over a wide range of head-flow conditions.

  19. Progress toward steady-state, high-efficiency vircators

    SciTech Connect

    Poulsen, P.; Pincosy, P.A.; Morrison, J.J.

    1990-12-05

    The resonance at which high-efficiency operation of virtual cathode oscillators is obtained occurs when the beam frequency equals the reflex frequency to within 2%. This tolerance limit in the frequency ratio implies that cathode closure in the anode-cathode gap is not acceptable. We have developed and tested a 6-cm{sup 2} cathode that will operate longer than 1 {mu}s at 300 A/cm{sup 2} without significant closure. As yet, the full-scale (>80-cm{sup 2}) cathode has not worked quite as well. In many tests, the cathode will operate in the emission-limited temperature/field (T/F) mode for approximately 300 ns, and then transition into explosive emission with a relatively slow ({approximately}0.5 cm/{mu}s) closure rate. The current density was 45 to 90 A/cm{sup 2}. We have not run high-power rf-emission tests under conditions where the diode stays open and in resonance for the duration of the rf pulse at a current density of 250 A/cm{sup 2}, which is required for 3-GHz operation; that test remains the focus of our continuing research. We have obtained long (600-ns) duration rf pulses at low power. We have also extended the data base on microwave generation at lower power and have shown that high-efficiency resonances will occur when a multiple of the reflex frequency equals the beam frequency. This allows greater flexibility in the design and scaling of the microwave device. 6 refs., 14 figs.

  20. Highly Efficient Thermoresponsive Nanocomposite for Controlled Release Applications

    NASA Astrophysics Data System (ADS)

    Yassine, Omar; Zaher, Amir; Li, Er Qiang; Alfadhel, Ahmed; Perez, Jose E.; Kavaldzhiev, Mincho; Contreras, Maria F.; Thoroddsen, Sigurdur T.; Khashab, Niveen M.; Kosel, Jurgen

    2016-06-01

    Highly efficient magnetic release from nanocomposite microparticles is shown, which are made of Poly (N-isopropylacrylamide) hydrogel with embedded iron nanowires. A simple microfluidic technique was adopted to fabricate the microparticles with a high control of the nanowire concentration and in a relatively short time compared to chemical synthesis methods. The thermoresponsive microparticles were used for the remotely triggered release of Rhodamine (B). With a magnetic field of only 1 mT and 20 kHz a drug release of 6.5% and 70% was achieved in the continuous and pulsatile modes, respectively. Those release values are similar to the ones commonly obtained using superparamagnetic beads but accomplished with a magnetic field of five orders of magnitude lower power. The high efficiency is a result of the high remanent magnetization of the nanowires, which produce a large torque when exposed to a magnetic field. This causes the nanowires to vibrate, resulting in friction losses and heating. For comparison, microparticles with superparamagnetic beads were also fabricated and tested; while those worked at 73 mT and 600 kHz, no release was observed at the low field conditions. Cytotoxicity assays showed similar and high cell viability for microparticles with nanowires and beads.

  1. Highly efficient baculovirus-mediated multigene delivery in primary cells

    PubMed Central

    Mansouri, Maysam; Bellon-Echeverria, Itxaso; Rizk, Aurélien; Ehsaei, Zahra; Cianciolo Cosentino, Chiara; Silva, Catarina S.; Xie, Ye; Boyce, Frederick M.; Davis, M. Wayne; Neuhauss, Stephan C. F.; Taylor, Verdon; Ballmer-Hofer, Kurt; Berger, Imre; Berger, Philipp

    2016-01-01

    Multigene delivery and subsequent cellular expression is emerging as a key technology required in diverse research fields including, synthetic and structural biology, cellular reprogramming and functional pharmaceutical screening. Current viral delivery systems such as retro- and adenoviruses suffer from limited DNA cargo capacity, thus impeding unrestricted multigene expression. We developed MultiPrime, a modular, non-cytotoxic, non-integrating, baculovirus-based vector system expediting highly efficient transient multigene expression from a variety of promoters. MultiPrime viruses efficiently transduce a wide range of cell types, including non-dividing primary neurons and induced-pluripotent stem cells (iPS). We show that MultiPrime can be used for reprogramming, and for genome editing and engineering by CRISPR/Cas9. Moreover, we implemented dual-host-specific cassettes enabling multiprotein expression in insect and mammalian cells using a single reagent. Our experiments establish MultiPrime as a powerful and highly efficient tool, to deliver multiple genes for a wide range of applications in primary and established mammalian cells. PMID:27143231

  2. Highly Efficient Thermoresponsive Nanocomposite for Controlled Release Applications

    PubMed Central

    Yassine, Omar; Zaher, Amir; Li, Er Qiang; Alfadhel, Ahmed; Perez, Jose E.; Kavaldzhiev, Mincho; Contreras, Maria F.; Thoroddsen, Sigurdur T.; Khashab, Niveen M.; Kosel, Jurgen

    2016-01-01

    Highly efficient magnetic release from nanocomposite microparticles is shown, which are made of Poly (N-isopropylacrylamide) hydrogel with embedded iron nanowires. A simple microfluidic technique was adopted to fabricate the microparticles with a high control of the nanowire concentration and in a relatively short time compared to chemical synthesis methods. The thermoresponsive microparticles were used for the remotely triggered release of Rhodamine (B). With a magnetic field of only 1 mT and 20 kHz a drug release of 6.5% and 70% was achieved in the continuous and pulsatile modes, respectively. Those release values are similar to the ones commonly obtained using superparamagnetic beads but accomplished with a magnetic field of five orders of magnitude lower power. The high efficiency is a result of the high remanent magnetization of the nanowires, which produce a large torque when exposed to a magnetic field. This causes the nanowires to vibrate, resulting in friction losses and heating. For comparison, microparticles with superparamagnetic beads were also fabricated and tested; while those worked at 73 mT and 600 kHz, no release was observed at the low field conditions. Cytotoxicity assays showed similar and high cell viability for microparticles with nanowires and beads. PMID:27335342

  3. Laser fusion

    SciTech Connect

    Smit, W.A.; Boskma, P.

    1980-12-01

    Unrestricted laser fusion offers nations an opportunity to circumvent arms control agreements and develop thermonuclear weapons. Early laser weapons research sought a clean radiation-free bomb to replace the fission bomb, but this was deceptive because a fission bomb was needed to trigger the fusion reaction and additional radioactivity was induced by generating fast neutrons. As laser-implosion experiments focused on weapons physics, simulating weapons effects, and applications for new weapons, the military interest shifted from developing a laser-ignited hydrogen bomb to more sophisticated weapons and civilian applications for power generation. Civilian and military research now overlap, making it possible for several countries to continue weapons activities and permitting proliferation of nuclear weapons. These countries are reluctant to include inertial confinement fusion research in the Non-Proliferation Treaty. 16 references. (DCK)

  4. Highly Efficient Prion Transmission by Blood Transfusion

    PubMed Central

    Andréoletti, Olivier; Litaise, Claire; Simmons, Hugh; Corbière, Fabien; Lugan, Séverine; Costes, Pierrette; Schelcher, François; Vilette, Didier; Grassi, Jacques; Lacroux, Caroline

    2012-01-01

    It is now clearly established that the transfusion of blood from variant CJD (v-CJD) infected individuals can transmit the disease. Since the number of asymptomatic infected donors remains unresolved, inter-individual v-CJD transmission through blood and blood derived products is a major public health concern. Current risk assessments for transmission of v-CJD by blood and blood derived products by transfusion rely on infectious titers measured in rodent models of Transmissible Spongiform Encephalopathies (TSE) using intra-cerebral (IC) inoculation of blood components. To address the biological relevance of this approach, we compared the efficiency of TSE transmission by blood and blood components when administrated either through transfusion in sheep or by intra-cerebral inoculation (IC) in transgenic mice (tg338) over-expressing ovine PrP. Transfusion of 200 µL of blood from asymptomatic infected donor sheep transmitted prion disease with 100% efficiency thereby displaying greater virulence than the transfusion of 200 mL of normal blood spiked with brain homogenate material containing 103ID50 as measured by intracerebral inoculation of tg338 mice (ID50 IC in tg338). This was consistent with a whole blood titer greater than 103.6 ID50 IC in tg338 per mL. However, when the same blood samples were assayed by IC inoculation into tg338 the infectious titers were less than 32 ID per mL. Whereas the transfusion of crude plasma to sheep transmitted the disease with limited efficacy, White Blood Cells (WBC) displayed a similar ability to whole blood to infect recipients. Strikingly, fixation of WBC with paraformaldehyde did not affect the infectivity titer as measured in tg338 but dramatically impaired disease transmission by transfusion in sheep. These results demonstrate that TSE transmission by blood transfusion can be highly efficient and that this efficiency is more dependent on the viability of transfused cells than the level of infectivity measured by IC

  5. High-Efficiency Harmonically Terminated Diode and Transistor Rectifiers

    SciTech Connect

    Roberg, M; Reveyrand, T; Ramos, I; Falkenstein, EA; Popovic, Z

    2012-12-01

    This paper presents a theoretical analysis of harmonically terminated high-efficiency power rectifiers and experimental validation on a class-C single Schottky-diode rectifier and a class-F-1 GaN transistor rectifier. The theory is based on a Fourier analysis of current and voltage waveforms, which arise across the rectifying element when different harmonic terminations are presented at its terminals. An analogy to harmonically terminated power amplifier (PA) theory is discussed. From the analysis, one can obtain an optimal value for the dc load given the RF circuit design. An upper limit on rectifier efficiency is derived for each case as a function of the device on-resistance. Measured results from fundamental frequency source-pull measurement of a Schottky diode rectifier with short-circuit terminations at the second and third harmonics are presented. A maximal device rectification efficiency of 72.8% at 2.45 GHz matches the theoretical prediction. A 2.14-GHz GaN HEMT rectifier is designed based on a class-F-1 PA. The gate of the transistor is terminated in an optimal impedance for self-synchronous rectification. Measurements of conversion efficiency and output dc voltage for varying gate RF impedance, dc load, and gate bias are shown with varying input RF power at the drain. The rectifier demonstrates an efficiency of 85% for a 10-W input RF power at the transistor drain with a dc voltage of 30 V across a 98-Omega resistor.

  6. High Efficiency Centrifugal Compressor for Rotorcraft Applications

    NASA Technical Reports Server (NTRS)

    Medic, Gorazd; Sharma, Om P.; Jongwook, Joo; Hardin, Larry W.; McCormick, Duane C.; Cousins, William T.; Lurie, Elizabeth A.; Shabbir, Aamir; Holley, Brian M.; Van Slooten, Paul R.

    2014-01-01

    The report "High Efficiency Centrifugal Compressor for Rotorcraft Applications" documents the work conducted at UTRC under the NRA Contract NNC08CB03C, with cost share 2/3 NASA, and 1/3 UTRC, that has been extended to 4.5 years. The purpose of this effort was to identify key technical barriers to advancing the state-of-the-art of small centrifugal compressor stages; to delineate the measurements required to provide insight into the flow physics of the technical barriers; to design, fabricate, install, and test a state-of-the-art research compressor that is representative of the rear stage of an axial-centrifugal aero-engine; and to acquire detailed aerodynamic performance and research quality data to clarify flow physics and to establish detailed data sets for future application. The design activity centered on meeting the goal set outlined in the NASA solicitation-the design target was to increase efficiency at higher work factor, while also reducing the maximum diameter of the stage. To fit within the existing Small Engine Components Test Facility at NASA Glenn Research Center (GRC) and to facilitate component re-use, certain key design parameters were fixed by UTRC, including impeller tip diameter, impeller rotational speed, and impeller inlet hub and shroud radii. This report describes the design effort of the High Efficiency Centrifugal Compressor stage (HECC) and delineation of measurements, fabrication of the compressor, and the initial tests that were performed. A new High-Efficiency Centrifugal Compressor stage with a very challenging reduction in radius ratio was successfully designed, fabricated and installed at GRC. The testing was successful, with no mechanical problems and the running clearances were achieved without impeller rubs. Overall, measured pressure ratio of 4.68, work factor of 0.81, and at design exit corrected flow rate of 3 lbm/s met the target requirements. Polytropic efficiency of 85.5 percent and stall margin of 7.5 percent were

  7. Multiple beam induction accelerators for heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Seidl, Peter A.; Barnard, John J.; Faltens, Andris; Friedman, Alex; Waldron, William L.

    2014-01-01

    Induction accelerators are appealing for heavy-ion driven inertial fusion energy (HIF) because of their high efficiency and their demonstrated capability to accelerate high beam current (≥10 kA in some applications). For the HIF application, accomplishments and challenges are summarized. HIF research and development has demonstrated the production of single ion beams with the required emittance, current, and energy suitable for injection into an induction linear accelerator. Driver scale beams have been transported in quadrupole channels of the order of 10% of the number of quadrupoles of a driver. We review the design and operation of induction accelerators and the relevant aspects of their use as drivers for HIF. We describe intermediate research steps that would provide the basis for a heavy-ion research facility capable of heating matter to fusion relevant temperatures and densities, and also to test and demonstrate an accelerator architecture that scales well to a fusion power plant.

  8. High efficiency beam splitting for H/sup -/ accelerators

    SciTech Connect

    Kramer, S.L.; Stipp, V.; Krieger, C.; Madsen, J.

    1985-01-01

    Beam splitting for high energy accelerators has typically involved a significant loss of beam and radiation. This paper reports on a new method of splitting beams for H/sup -/ accelerators. This technique uses a high intensity flash of light to strip a fraction of the H/sup -/ beam to H/sup 0/ which are then easily separated by a small bending magnet. A system using a 900-watt (average electrical power) flashlamp and a highly efficient collector will provide 10/sup -3/ to 10/sup -2/ splitting of a 50 MeV H/sup -/ beam. Results on the operation and comparisons with stripping cross sections are presented. Also discussed is the possibility for developing this system to yield a higher stripping fraction.

  9. High Efficiency InP Solar Cells Through Nanostructuring

    NASA Astrophysics Data System (ADS)

    Goldman, Daniel; Murray, Joseph; Munday, Jeremy

    We describe high efficiency InP solar cells which utilize a periodic array of optically designed TiO2 nanocylinders. Optical and electronic simulations were performed to determine the spectrally resolved reflectivity and I-V characteristics of potential devices under AM1.5G illumination. The reflectivity of InP solar cells with these nanocylinders is found to have an average value of 2% over the visible and near-IR spectral range, which outperforms traditional antireflection coatings. Coupling between Mie scattering resonances and thin film interference effects is found to accurately describe the optical enhancement provided by the nanocylinders. These nanostructured solar cells have power conversion efficiencies greater than 23%, which is comparable to the highest quoted efficiencies for InP solar cells.

  10. Highly Efficient Perovskite Solar Cells with Tunable Structural Color

    PubMed Central

    2015-01-01

    The performance of perovskite solar cells has been progressing over the past few years and efficiency is likely to continue to increase. However, a negative aspect for the integration of perovskite solar cells in the built environment is that the color gamut available in these materials is very limited and does not cover the green-to-blue region of the visible spectrum, which has been a big selling point for organic photovoltaics. Here, we integrate a porous photonic crystal (PC) scaffold within the photoactive layer of an opaque perovskite solar cell following a bottom-up approach employing inexpensive and scalable liquid processing techniques. The photovoltaic devices presented herein show high efficiency with tunable color across the visible spectrum. This now imbues the perovskite solar cells with highly desirable properties for cladding in the built environment and encourages design of sustainable colorful buildings and iridescent electric vehicles as future power generation sources. PMID:25650872

  11. Highly efficient solar cells based on poly(3-butylthiophene) nanowires.

    PubMed

    Xin, Hao; Kim, Felix Sunjoo; Jenekhe, Samson A

    2008-04-23

    Poly(3-butylthiophene) (P3BT) nanowires, prepared by solution-phase self-assembly, have been used to construct highly efficient P3BT/fullerene nanocomposite solar cells. The fullerene/P3BT nanocomposite films showed an electrically bicontinuous nanoscale morphology with average field-effect hole mobilities as high as 8.0 x 10(-3) cm2/Vs due to the interconnected P3BT nanowire network revealed by TEM and AFM imaging. The power conversion efficiency of fullerene/P3BT nanowire devices was 3.0% (at 100 mW/cm2, AM1.5) in air and found to be identical with our similarly tested fullerene/poly(3-hexylthiophene) photovoltaic cells. This discovery expands the scope of promising materials and architectures for efficient bulk heterojunction solar cells.

  12. High efficiency silicon nanohole/organic heterojunction hybrid solar cell

    NASA Astrophysics Data System (ADS)

    Hong, Lei; Wang, Xincai; Zheng, Hongyu; He, Lining; Wang, Hao; Yu, Hongyu; Rusli

    2014-02-01

    High efficiency hybrid solar cells are fabricated based on silicon with a nanohole (SiNH) structure and poly (3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). The SiNH structure is fabricated using electroless chemical etching with silver catalyst, and the heterojunction is formed by spin coating of PEDOT on the SiNH. The hybrid cells are optimized by varying the hole depth, and a maximum power conversion efficiency of 8.3% is achieved with a hole depth of 1 μm. The SiNH hybrid solar cell exhibits a strong antireflection and light trapping property attributed to the sub-wavelength dimension of the SiNH structure.

  13. High efficiency >26 W diode end-pumped Alexandrite laser.

    PubMed

    Teppitaksak, Achaya; Minassian, Ara; Thomas, Gabrielle M; Damzen, Michael J

    2014-06-30

    We show for the first time that multi-ten Watt operation of an Alexandrite laser can be achieved with direct red diode-pumping and with high efficiency. An investigation of diode end-pumped Alexandrite rod lasers demonstrates continuous-wave output power in excess of 26W, more than an order of magnitude higher than previous diode end-pumping systems, and slope efficiency 49%, the highest reported for a diode-pumped Alexandrite laser. Wavelength tuning from 730 to 792nm is demonstrated using self-seeding feedback from an external grating. Q-switched laser operation based on polarization-switching to a lower gain axis of Alexandrite has produced ~mJ-pulse energy at 1kHz pulse rate in fundamental TEM(00) mode.

  14. Highly efficient perovskite solar cells with tunable structural color.

    PubMed

    Zhang, Wei; Anaya, Miguel; Lozano, Gabriel; Calvo, Mauricio E; Johnston, Michael B; Míguez, Hernán; Snaith, Henry J

    2015-03-11

    The performance of perovskite solar cells has been progressing over the past few years and efficiency is likely to continue to increase. However, a negative aspect for the integration of perovskite solar cells in the built environment is that the color gamut available in these materials is very limited and does not cover the green-to-blue region of the visible spectrum, which has been a big selling point for organic photovoltaics. Here, we integrate a porous photonic crystal (PC) scaffold within the photoactive layer of an opaque perovskite solar cell following a bottom-up approach employing inexpensive and scalable liquid processing techniques. The photovoltaic devices presented herein show high efficiency with tunable color across the visible spectrum. This now imbues the perovskite solar cells with highly desirable properties for cladding in the built environment and encourages design of sustainable colorful buildings and iridescent electric vehicles as future power generation sources.

  15. High efficiency silicon nanohole/organic heterojunction hybrid solar cell

    SciTech Connect

    Hong, Lei; Wang, Xincai; Zheng, Hongyu; He, Lining; Wang, Hao; Rusli E-mail: erusli@ntu.edu.sg; Yu, Hongyu E-mail: erusli@ntu.edu.sg

    2014-02-03

    High efficiency hybrid solar cells are fabricated based on silicon with a nanohole (SiNH) structure and poly (3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). The SiNH structure is fabricated using electroless chemical etching with silver catalyst, and the heterojunction is formed by spin coating of PEDOT on the SiNH. The hybrid cells are optimized by varying the hole depth, and a maximum power conversion efficiency of 8.3% is achieved with a hole depth of 1 μm. The SiNH hybrid solar cell exhibits a strong antireflection and light trapping property attributed to the sub-wavelength dimension of the SiNH structure.

  16. High efficiency thin-film GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Zwerdling, S.; Wang, K. L.; Yeh, Y. C. M.

    1981-01-01

    The paper demonstrates the feasibility of producing high-efficiency GaAs solar cells with high power-to-weight ratios by organic metallic chemical vapor deposition (OM-CVD) growth of thin epi-layers on suitable substrates. An AM1 conversion efficiency of 18% (14% AM0), or 17% (13% AM0) with a 5% grid coverage is achieved for a single-crystal GaAs n(+)/p cell grown by OM-CVD on a Ge wafer. Thin GaAs epi-layers OM-CVD grown can be fabricated with good crystallographic quality using a Si-substrate on which a thin Ge epi-interlayer is first deposited by CVD from GeH4 and processed for improved surface morphology

  17. Laser absorption, power transfer, and radiation symmetry during the first shock of inertial confinement fusion gas-filled hohlraum experiments

    NASA Astrophysics Data System (ADS)

    Pak, A.; Dewald, E. L.; Landen, O. L.; Milovich, J.; Strozzi, D. J.; Berzak Hopkins, L. F.; Bradley, D. K.; Divol, L.; Ho, D. D.; MacKinnon, A. J.; Meezan, N. B.; Michel, P.; Moody, J. D.; Moore, A. S.; Schneider, M. B.; Town, R. P. J.; Hsing, W. W.; Edwards, M. J.

    2015-12-01

    Temporally resolved measurements of the hohlraum radiation flux asymmetry incident onto a bismuth coated surrogate capsule have been made over the first two nanoseconds of ignition relevant laser pulses. Specifically, we study the P2 asymmetry of the incoming flux as a function of cone fraction, defined as the inner-to-total laser beam power ratio, for a variety of hohlraums with different scales and gas fills. This work was performed to understand the relevance of recent experiments, conducted in new reduced-scale neopentane gas filled hohlraums, to full scale helium filled ignition targets. Experimental measurements, matched by 3D view factor calculations, are used to infer differences in symmetry, relative beam absorption, and cross beam energy transfer (CBET), employing an analytic model. Despite differences in hohlraum dimensions and gas fill, as well as in laser beam pointing and power, we find that laser absorption, CBET, and the cone fraction, at which a symmetric flux is achieved, are similar to within 25% between experiments conducted in the reduced and full scale hohlraums. This work demonstrates a close surrogacy in the dynamics during the first shock between reduced-scale and full scale implosion experiments and is an important step in enabling the increased rate of study for physics associated with inertial confinement fusion.

  18. Development of negative ion extractor in the high-power and long-pulse negative ion source for fusion application

    SciTech Connect

    Kashiwagi, M. Umeda, N.; Tobari, H.; Kojima, A.; Yoshida, M.; Taniguchi, M.; Dairaku, M.; Maejima, T.; Yamanaka, H.; Watanabe, K.; Inoue, T.; Hanada, M.

    2014-02-15

    High power and long-pulse negative ion extractor, which is composed of the plasma grid (PG) and the extraction grid (EXG), is newly developed toward the neutral beam injector for heating and current drive of future fusion machines such as ITER, JT-60 Super Advanced and DEMO reactor. The PG is designed to enhance surface production of negative ions efficiently by applying the chamfered aperture. The efficiency of the negative ion production for the discharge power increased by a factor of 1.3 against that of the conventional PG. The EXG is also designed with the thermal analysis to upgrade the cooling capability for the long pulse operation of >1000 s required in ITER. Though the magnetic field for electron suppression is reduced to 0.75 of that in the conventional EXG due to this upgrade, it was experimentally confirmed that the extracted electron current can be suppressed to the allowable level for the long pulse operation. These results show that newly developed extractor has the high potential for the long pulse extraction of the negative ions.

  19. Laser absorption, power transfer, and radiation symmetry during the first shock of inertial confinement fusion gas-filled hohlraum experiments

    SciTech Connect

    Pak, A.; Dewald, E. L.; Landen, O. L.; Milovich, J.; Strozzi, D. J.; Berzak Hopkins, L. F.; Bradley, D. K.; Divol, L.; Ho, D. D.; MacKinnon, A. J.; Meezan, N. B.; Michel, P.; Moody, J. D.; Moore, A. S.; Schneider, M. B.; Town, R. P. J.; Hsing, W. W.; Edwards, M. J.

    2015-12-15

    Temporally resolved measurements of the hohlraum radiation flux asymmetry incident onto a bismuth coated surrogate capsule have been made over the first two nanoseconds of ignition relevant laser pulses. Specifically, we study the P2 asymmetry of the incoming flux as a function of cone fraction, defined as the inner-to-total laser beam power ratio, for a variety of hohlraums with different scales and gas fills. This work was performed to understand the relevance of recent experiments, conducted in new reduced-scale neopentane gas filled hohlraums, to full scale helium filled ignition targets. Experimental measurements, matched by 3D view factor calculations, are used to infer differences in symmetry, relative beam absorption, and cross beam energy transfer (CBET), employing an analytic model. Despite differences in hohlraum dimensions and gas fill, as well as in laser beam pointing and power, we find that laser absorption, CBET, and the cone fraction, at which a symmetric flux is achieved, are similar to within 25% between experiments conducted in the reduced and full scale hohlraums. This work demonstrates a close surrogacy in the dynamics during the first shock between reduced-scale and full scale implosion experiments and is an important step in enabling the increased rate of study for physics associated with inertial confinement fusion.

  20. Evaluating performance of high efficiency mist eliminators

    SciTech Connect

    Waggoner, Charles A.; Parsons, Michael S.; Giffin, Paxton K.

    2013-07-01

    Processing liquid wastes frequently generates off gas streams with high humidity and liquid aerosols. Droplet laden air streams can be produced from tank mixing or sparging and processes such as reforming or evaporative volume reduction. Unfortunately these wet air streams represent a genuine threat to HEPA filters. High efficiency mist eliminators (HEME) are one option for removal of liquid aerosols with high dissolved or suspended solids content. HEMEs have been used extensively in industrial applications, however they have not seen widespread use in the nuclear industry. Filtering efficiency data along with loading curves are not readily available for these units and data that exist are not easily translated to operational parameters in liquid waste treatment plants. A specialized test stand has been developed to evaluate the performance of HEME elements under use conditions of a US DOE facility. HEME elements were tested at three volumetric flow rates using aerosols produced from an iron-rich waste surrogate. The challenge aerosol included submicron particles produced from Laskin nozzles and super micron particles produced from a hollow cone spray nozzle. Test conditions included ambient temperature and relative humidities greater than 95%. Data collected during testing HEME elements from three different manufacturers included volumetric flow rate, differential temperature across the filter housing, downstream relative humidity, and differential pressure (dP) across the filter element. Filter challenge was discontinued at three intermediate dPs and the filter to allow determining filter efficiency using dioctyl phthalate and then with dry surrogate aerosols. Filtering efficiencies of the clean HEME, the clean HEME loaded with water, and the HEME at maximum dP were also collected using the two test aerosols. Results of the testing included differential pressure vs. time loading curves for the nine elements tested along with the mass of moisture and solid

  1. Novel Nanophosphors for High Efficiency Fluorescent Lamps

    SciTech Connect

    Alok Srivatava

    2007-03-31

    This is the Final Report of the Novel Nanophosphors for High Efficiency Fluorescent Lamps, Department of Energy (DOE). The overall goal of this three-year program is to develop novel hybrid phosphors by coating commercially available lamp phosphors with highly stable wide band-gap nanocrystalline phosphors (NCP). The prime technical approach is the development of NCP quantum-splitting phosphor (QSP) and ultra-violet (UV) emitting phosphors with quantum efficiencies exceeding that of the conventional phosphors at 185 nm. The novel hybrid phosphors will increase the efficiency of the fluorescent lamps by up to 32%, enabling total energy savings of 0.26 quads, the reduction in the U.S. energy bill by $6.5 billion and the reduction of the annual carbon emission by 4.1 billion kilogram. Our work started by investigating through modeling calculations the requirement for the particle size of the NCP. Our work to develop suitable nanocrystalline phosphors started with the known oxide quantum splitting and UV emitting phosphors. We demonstrated several synthesis techniques for the production of high quality nanocrystalline materials that crystallizes in the desired phase and with the desired particle size. In collaboration with our subcontractor we demonstrated the feasibility for the manufacture of NC phosphors. We also demonstrated novel techniques of coating the NCP on the surface of micron sized phosphors. Our chief achievement pertains to the successful testing of the coated hybrid phosphor systems in linear fluorescent lamps. In linear fluorescent lamp tests, we have demonstrated up to 7% increase in the efficacy of hybrid phosphors over the conventional (uncoated) phosphors. We have also demonstrated the improvement in the lumen maintenance of the coated phosphors. A hybrid phosphor system based on the commercial red emitting phosphor, Y{sub 2}O{sub 3}:Eu{sup 3+} did not show the anticipated improvement in lamp efficacy. We explored the reasons for this observation

  2. Tailored Materials for High Efficiency CIDI Engines

    SciTech Connect

    Grant, G.J.; Jana, S.

    2012-03-30

    The overall goal of the project, Tailored Materials for High Efficiency Compression Ignition Direct Injection (CIDI) Engines, is to enable the implementation of new combustion strategies, such as homogeneous charge compression ignition (HCCI), that have the potential to significantly increase the energy efficiency of current diesel engines and decrease fuel consumption and environmental emissions. These strategies, however, are increasing the demands on conventional engine materials, either from increases in peak cylinder pressure (PCP) or from increases in the temperature of operation. The specific objective of this project is to investigate the application of a new material processing technology, friction stir processing (FSP), to improve the thermal and mechanical properties of engine components. The concept is to modify the surfaces of conventional, low-cost engine materials. The project focused primarily on FSP in aluminum materials that are compositional analogs to the typical piston and head alloys seen in small- to mid-sized CIDI engines. Investigations have been primarily of two types over the duration of this project: (1) FSP of a cast hypoeutectic Al-Si-Mg (A356/357) alloy with no introduction of any new components, and (2) FSP of Al-Cu-Ni alloys (Alloy 339) by physically stirring-in various quantities of carbon nanotubes/nanofibers or carbon fibers. Experimental work to date on aluminum systems has shown significant increases in fatigue lifetime and stress-level performance in aluminum-silicon alloys using friction processing alone, but work to demonstrate the addition of carbon nanotubes and fibers into aluminum substrates has shown mixed results due primarily to the difficulty in achieving porosity-free, homogeneous distributions of the particulate. A limited effort to understand the effects of FSP on steel materials was also undertaken during the course of this project. Processed regions were created in high-strength, low-alloyed steels up to 0.5 in

  3. Flexible, highly efficient all-polymer solar cells.

    PubMed

    Kim, Taesu; Kim, Jae-Han; Kang, Tae Eui; Lee, Changyeon; Kang, Hyunbum; Shin, Minkwan; Wang, Cheng; Ma, Biwu; Jeong, Unyong; Kim, Taek-Soo; Kim, Bumjoon J

    2015-10-09

    All-polymer solar cells have shown great potential as flexible and portable power generators. These devices should offer good mechanical endurance with high power-conversion efficiency for viability in commercial applications. In this work, we develop highly efficient and mechanically robust all-polymer solar cells that are based on the PBDTTTPD polymer donor and the P(NDI2HD-T) polymer acceptor. These systems exhibit high power-conversion efficiency of 6.64%. Also, the proposed all-polymer solar cells have even better performance than the control polymer-fullerene devices with phenyl-C61-butyric acid methyl ester (PCBM) as the electron acceptor (6.12%). More importantly, our all-polymer solar cells exhibit dramatically enhanced strength and flexibility compared with polymer/PCBM devices, with 60- and 470-fold improvements in elongation at break and toughness, respectively. The superior mechanical properties of all-polymer solar cells afford greater tolerance to severe deformations than conventional polymer-fullerene solar cells, making them much better candidates for applications in flexible and portable devices.

  4. Highly Efficient Small Form Factor LED Retrofit Lamp

    SciTech Connect

    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.

  5. Flexible, highly efficient all-polymer solar cells

    PubMed Central

    Kim, Taesu; Kim, Jae-Han; Kang, Tae Eui; Lee, Changyeon; Kang, Hyunbum; Shin, Minkwan; Wang, Cheng; Ma, Biwu; Jeong, Unyong; Kim, Taek-Soo; Kim, Bumjoon J.

    2015-01-01

    All-polymer solar cells have shown great potential as flexible and portable power generators. These devices should offer good mechanical endurance with high power-conversion efficiency for viability in commercial applications. In this work, we develop highly efficient and mechanically robust all-polymer solar cells that are based on the PBDTTTPD polymer donor and the P(NDI2HD-T) polymer acceptor. These systems exhibit high power-conversion efficiency of 6.64%. Also, the proposed all-polymer solar cells have even better performance than the control polymer-fullerene devices with phenyl-C61-butyric acid methyl ester (PCBM) as the electron acceptor (6.12%). More importantly, our all-polymer solar cells exhibit dramatically enhanced strength and flexibility compared with polymer/PCBM devices, with 60- and 470-fold improvements in elongation at break and toughness, respectively. The superior mechanical properties of all-polymer solar cells afford greater tolerance to severe deformations than conventional polymer-fullerene solar cells, making them much better candidates for applications in flexible and portable devices. PMID:26449658

  6. High efficiency stoichiometric internal combustion engine system

    DOEpatents

    Winsor, Richard Edward; Chase, Scott Allen

    2009-06-02

    A power system including a stoichiometric compression ignition engine in which a roots blower is positioned in the air intake for the engine to control air flow. Air flow is decreased during part power conditions to maintain the air-fuel ratio in the combustion chamber of the engine at stoichiometric, thus enabling the use of inexpensive three-way catalyst to reduce oxides of nitrogen. The roots blower is connected to a motor generator so that when air flow is reduced, electrical energy is stored which is made available either to the roots blower to temporarily increase air flow or to the system electrical load and thus recapture energy that would otherwise be lost in reducing air flow.

  7. High efficiency Brayton cycles using LNG

    DOEpatents

    Morrow, Charles W.

    2006-04-18

    A modified, closed-loop Brayton cycle power conversion system that uses liquefied natural gas as the cold heat sink media. When combined with a helium gas cooled nuclear reactor, achievable efficiency can approach 68 76% (as compared to 35% for conventional steam cycle power cooled by air or water). A superheater heat exchanger can be used to exchange heat from a side-stream of hot helium gas split-off from the primary helium coolant loop to post-heat vaporized natural gas exiting from low and high-pressure coolers. The superheater raises the exit temperature of the natural gas to close to room temperature, which makes the gas more attractive to sell on the open market. An additional benefit is significantly reduced costs of a LNG revaporization plant, since the nuclear reactor provides the heat for vaporization instead of burning a portion of the LNG to provide the heat.

  8. High Efficiency Thermoelectric Materials and Devices

    NASA Technical Reports Server (NTRS)

    Kochergin, Vladimir (Inventor)

    2013-01-01

    Growth of thermoelectric materials in the form of quantum well super-lattices on three-dimensionally structured substrates provide the means to achieve high conversion efficiency of the thermoelectric module combined with inexpensiveness of fabrication and compatibility with large scale production. Thermoelectric devices utilizing thermoelectric materials in the form of quantum well semiconductor super-lattices grown on three-dimensionally structured substrates provide improved thermoelectric characteristics that can be used for power generation, cooling and other applications..

  9. Highly Efficient Contactless Electrical Energy Transmission System

    NASA Astrophysics Data System (ADS)

    Ayano, Hideki; Nagase, Hiroshi; Inaba, Hiromi

    This paper proposes a new concept for a contactless electrical energy transmission system for an elevator and an automated guided vehicle. The system has rechargeable batteries on the car and electrical energy is supplied at a specific place. When electric power is supplied to the car, it runs automatically and approaches the battery charger. Therefore, a comparatively large gap is needed between the primary transformer at the battery charger and the secondary transformer on the car in order to prevent damage which would be caused by a collision. In this case, a drop of the transformer coupling rate due to the large gap must be prevented. In conventional contactless electrical energy transmission technology, since electric power is received by a pick-up coil from a power line, a large-sized transformer is required. And when the distance over which the car runs is long, the copper loss of the line also increases. The developed system adopts a high frequency inverter using a soft switching method to miniaturize the transformer. The system has a coupling rate of 0.88 for a transformer gap length of 10mm and can operate at 91% efficiency.

  10. A High Efficiency DC-DC Converter Topology Suitable for Distributed Large Commercial and Utility Scale PV Systems

    SciTech Connect

    Agamy, Mohammed S; Harfman-Todorovic, Maja; Elasser, Ahmed; Steigerwald, Robert L; Sabate, Juan A; Chi, Song; McCann, Adam J; Zhang, Li; Mueller, Frank

    2012-09-01

    In this paper a DC-DC power converter for distributed photovoltaic plant architectures is presented. The proposed converter has the advantages of simplicity, high efficiency, and low cost. High efficiency is achieved by having a portion of the input PV power directly fed forward to the output without being processed by the converter. The operation of this converter also allows for a simplified maximum power point tracker design using fewer measurements

  11. Development of high power CW 3.7 GHz klystrons for fusion experiments on Tore Supra

    SciTech Connect

    Magne, R.; Armitano, A.; Berger-By, G.; Bouquey, F.; Corbel, E.; Delpech, L.; Mollard, P.; Prou, M.; Samaille, F.; Volpe, D.; Beunas, A.; Kazarian, F.

    2011-07-01

    In the frame of the CIMES project, a collaborative effort between Association Euratom-CEA and Thales Electron Devices (TED) has led to the development of a high power CW klystron TH 2103 C, working at 3.7 GHz, for plasma heating and current drive for the Tokamak Tore Supra. A prototype has been manufactured and thoroughly tested on water load in December 2007 to verify that all the parameters met the specifications. The paper will present in detail the process and results of the test of the klystrons.

  12. Magnetic fusion reactor economics

    SciTech Connect

    Krakowski, R.A.

    1995-12-01

    An almost primordial trend in the conversion and use of energy is an increased complexity and cost of conversion systems designed to utilize cheaper and more-abundant fuels; this trend is exemplified by the progression fossil fission {yields} fusion. The present projections of the latter indicate that capital costs of the fusion ``burner`` far exceed any commensurate savings associated with the cheapest and most-abundant of fuels. These projections suggest competitive fusion power only if internal costs associate with the use of fossil or fission fuels emerge to make them either uneconomic, unacceptable, or both with respect to expensive fusion systems. This ``implementation-by-default`` plan for fusion is re-examined by identifying in general terms fusion power-plant embodiments that might compete favorably under conditions where internal costs (both economic and environmental) of fossil and/or fission are not as great as is needed to justify the contemporary vision for fusion power. Competitive fusion power in this context will require a significant broadening of an overly focused program to explore the physics and simbiotic technologies leading to more compact, simplified, and efficient plasma-confinement configurations that reside at the heart of an attractive fusion power plant.

  13. Magnetic-confinement fusion

    NASA Astrophysics Data System (ADS)

    Ongena, J.; Koch, R.; Wolf, R.; Zohm, H.

    2016-05-01

    Our modern society requires environmentally friendly solutions for energy production. Energy can be released not only from the fission of heavy nuclei but also from the fusion of light nuclei. Nuclear fusion is an important option for a clean and safe solution for our long-term energy needs. The extremely high temperatures required for the fusion reaction are routinely realized in several magnetic-fusion machines. Since the early 1990s, up to 16 MW of fusion power has been released in pulses of a few seconds, corresponding to a power multiplication close to break-even. Our understanding of the very complex behaviour of a magnetized plasma at temperatures between 150 and 200 million °C surrounded by cold walls has also advanced substantially. This steady progress has resulted in the construction of ITER, a fusion device with a planned fusion power output of 500 MW in pulses of 400 s. ITER should provide answers to remaining important questions on the integration of physics and technology, through a full-size demonstration of a tenfold power multiplication, and on nuclear safety aspects. Here we review the basic physics underlying magnetic fusion: past achievements, present efforts and the prospects for future production of electrical energy. We also discuss questions related to the safety, waste management and decommissioning of a future fusion power plant.

  14. High efficiency coaxial klystron-like relativistic backward wave oscillator with a premodulation cavity

    SciTech Connect

    Xiao Renzhen; Teng Yan; Chen Changhua; Sun Jun

    2011-11-15

    The klystron-like relativistic backward wave oscillator (RBWO) combines the transition radiation with Cerenkov radiation and has demonstrated microwave output of high power and high efficiency. The coaxial slow wave structure device can produce microwave with a lower frequency in a smaller cross section. For the purpose of high efficiency, low frequency, and miniaturization, a coaxial klystron-like RBWO with a premodulation cavity is presented. Particle-in-cell simulations show that a microwave with power of 1.15 GW and frequency of 2.1 GHz is generated with conversion efficiency of 48%, whereas for the device with a reflector, the efficiency is 38%.

  15. A ``Stepladder'' Approach to a Steady State Tokamak Fusion Power Plant

    NASA Astrophysics Data System (ADS)

    Zohm, Hartmut; Bock, Alexander; Fable, Emiliano; Stober, Joerg; Traeuble, Frederik

    2016-10-01

    In the EU strategy to an FPP, DEMO is the single step between ITER and an FPP. It is not obvious how to arrive at a DEMO design point in this strategy. We propose to avoid large scenario development steps in an ITER-DEMO-FPP step-ladder, since no other machines can qualify the scenarios. Thus, DEMO becomes a technology demonstrator, not a plasma physics experiment. We characterize the plasma scenario in terms of the quantities βN, q, H and fGW. To ensure adequate divertor performance, constant ne is chosen. Different from previous approaches, ρ* and ν* will vary throughout the stepladder based on physics arguments that below minimum values, their variation is no longer important. This leaves open the choice of machine parameters A, R and B. Fixing A to the ITER value, constant fGW and absolute ne lead to B/R = const. At constant q, βN and A, B and R increase proportional to Pfus1 / 7 in the stepladder. The power needed to drive the current in steady state varies similarly, so from DEMO to an FPP a significant decrease in recirculating power fraction occurs. A viable divertor solution and access to H-mode are considered explicitly. An example for such a stepladder is discussed, based on recent ASDEX Upgrade results in steady state. Also at Faculty of Physics, Ludwig-Maximilians-Universität, D-80799 München, Germany.

  16. High efficiency quasi-monochromatic infrared emitter

    NASA Astrophysics Data System (ADS)

    Brucoli, Giovanni; Bouchon, Patrick; Haïdar, Riad; Besbes, Mondher; Benisty, Henri; Greffet, Jean-Jacques

    2014-02-01

    Incandescent radiation sources are widely used as mid-infrared emitters owing to the lack of alternative for compact and low cost sources. A drawback of miniature hot systems such as membranes is their low efficiency, e.g., for battery powered systems. For targeted narrow-band applications such as gas spectroscopy, the efficiency is even lower. In this paper, we introduce design rules valid for very generic membranes demonstrating that their energy efficiency for use as incandescent infrared sources can be increased by two orders of magnitude.

  17. High efficiency quasi-monochromatic infrared emitter

    SciTech Connect

    Brucoli, Giovanni; Besbes, Mondher; Benisty, Henri Greffet, Jean-Jacques; Bouchon, Patrick; Haïdar, Riad

    2014-02-24

    Incandescent radiation sources are widely used as mid-infrared emitters owing to the lack of alternative for compact and low cost sources. A drawback of miniature hot systems such as membranes is their low efficiency, e.g., for battery powered systems. For targeted narrow-band applications such as gas spectroscopy, the efficiency is even lower. In this paper, we introduce design rules valid for very generic membranes demonstrating that their energy efficiency for use as incandescent infrared sources can be increased by two orders of magnitude.

  18. High efficiency quantum cascade laser frequency comb

    PubMed Central

    Lu, Quanyong; Wu, Donghai; Slivken, Steven; Razeghi, Manijeh

    2017-01-01

    An efficient mid-infrared frequency comb source is of great interest to high speed, high resolution spectroscopy and metrology. Here we demonstrate a mid-IR quantum cascade laser frequency comb with a high power output and narrow beatnote linewidth at room temperature. The active region was designed with a strong-coupling between the injector and the upper lasing level for high internal quantum efficiency and a broadband gain. The group velocity dispersion was engineered for efficient, broadband mode-locking via four wave mixing. The comb device exhibits a narrow intermode beatnote linewidth of 50.5 Hz and a maximum wall-plug efficiency of 6.5% covering a spectral coverage of 110 cm−1 at λ ~ 8 μm. The efficiency is improved by a factor of 6 compared with previous demonstrations. The high power efficiency and narrow beatnote linewidth will greatly expand the applications of quantum cascade laser frequency combs including high-precision remote sensing and spectroscopy. PMID:28262834

  19. High efficiency quantum cascade laser frequency comb.

    PubMed

    Lu, Quanyong; Wu, Donghai; Slivken, Steven; Razeghi, Manijeh

    2017-03-06

    An efficient mid-infrared frequency comb source is of great interest to high speed, high resolution spectroscopy and metrology. Here we demonstrate a mid-IR quantum cascade laser frequency comb with a high power output and narrow beatnote linewidth at room temperature. The active region was designed with a strong-coupling between the injector and the upper lasing level for high internal quantum efficiency and a broadband gain. The group velocity dispersion was engineered for efficient, broadband mode-locking via four wave mixing. The comb device exhibits a narrow intermode beatnote linewidth of 50.5 Hz and a maximum wall-plug efficiency of 6.5% covering a spectral coverage of 110 cm(-1) at λ ~ 8 μm. The efficiency is improved by a factor of 6 compared with previous demonstrations. The high power efficiency and narrow beatnote linewidth will greatly expand the applications of quantum cascade laser frequency combs including high-precision remote sensing and spectroscopy.

  20. High efficiency quantum cascade laser frequency comb

    NASA Astrophysics Data System (ADS)

    Lu, Quanyong; Wu, Donghai; Slivken, Steven; Razeghi, Manijeh

    2017-03-01

    An efficient mid-infrared frequency comb source is of great interest to high speed, high resolution spectroscopy and metrology. Here we demonstrate a mid-IR quantum cascade laser frequency comb with a high power output and narrow beatnote linewidth at room temperature. The active region was designed with a strong-coupling between the injector and the upper lasing level for high internal quantum efficiency and a broadband gain. The group velocity dispersion was engineered for efficient, broadband mode-locking via four wave mixing. The comb device exhibits a narrow intermode beatnote linewidth of 50.5 Hz and a maximum wall-plug efficiency of 6.5% covering a spectral coverage of 110 cm‑1 at λ ~ 8 μm. The efficiency is improved by a factor of 6 compared with previous demonstrations. The high power efficiency and narrow beatnote linewidth will greatly expand the applications of quantum cascade laser frequency combs including high-precision remote sensing and spectroscopy.

  1. Microstructural Evolution and Creep-Rupture Behavior of Fusion Welds Involving Alloys for Advanced Ultrasupercritical Power Generation

    NASA Astrophysics Data System (ADS)

    Bechetti, Daniel H., Jr.

    Projections for large increases in the global demand for electric power produced by the burning of fossil fuels, in combination with growing environmental concerns surrounding these fuel sources, have sparked initiatives in the United States, Europe, and Asia aimed at developing a new generation of coal fired power plant, termed Advanced Ultrasupercritical (A-USC). These plants are slated to operate at higher steam temperatures and pressures than current generation plants, and in so doing will offer increased process cycle efficiency and reduced greenhouse gas emissions. Several gamma' precipitation strengthened Ni-based superalloys have been identified as candidates for the hottest sections of these plants, but the microstructural instability and poor creep behavior (compared to wrought products) of fusion welds involving these alloys present significant hurdles to their implementation and a gap in knowledge that must be addressed. In this work, creep testing and in-depth microstructural characterization have been used to provide insight into the long-term performance of these alloys. First, an investigation of the weld metal microstructural evolution as it relates to creep strength reductions in A-USC alloys INCONELRTM 740, NIMONICRTM 263 (INCONEL and NIMONIC are registered trademarks of Special Metals Corporation), and HaynesRTM 282RTM (Haynes and 282 are registered trademarks of Haynes International) was performed. gamma'-precipitate free zones were identified in two of these three alloys, and their development was linked to the evolution of phases that precipitate at the expense of gamma'. Alloy 282 was shown to avoid precipitate free zone formation because the precipitates that form during long term aging in this alloy are poor in the gamma'-forming elements. Next, the microstructural evolution of INCONELRTM 740H (a compositional variant of alloy 740) during creep was investigated. Gleeble-based interrupted creep and creep-rupture testing was used to

  2. Safety training and safe operating procedures written for PBFA (Particle Beam Fusion Accelerator) II and applicable to other pulsed power facilities

    SciTech Connect

    Donovan, G.L.; Goldstein, S.A.

    1986-12-01

    To ensure that work in advancing pulsed power technology is performed with an acceptably low risk, pulsed power research facilities at Sandia National Laboratories must satisfy general safety guidelines established by the Department of Energy, policies and formats of the Environment, Safety, and Health (ES and H) Department, and detailed procedures formulated by the Pulsed Power Sciences Directorate. The approach to safety training and to writing safe operating procedures, and the procedures presented here are specific to the Particle Beam Fusion Accelerator II (PBFA II) Facility but are applicable as guidelines to other research and development facilities which have similar hazards.

  3. High-efficiency isolated SEPIC converter with reduced conduction losses for LED displays

    NASA Astrophysics Data System (ADS)

    Choi, Woo-Young; Yang, Min-Kwon

    2014-11-01

    This paper proposes a high-efficiency isolated bridgeless single-ended primary inductor converter (SEPIC) for light-emitting-diode (LED) displays. The proposed isolated SEPIC converter can supply LED back-light power with reduced conduction losses. Switching power losses as well as conduction losses are reduced. The proposed converter is theoretically analysed. Experimental results based on a 28 V, 300 W back-light power are discussed to verify the performance of the proposed converter.

  4. Advanced latent heat of fusion thermal energy storage for solar power systems

    NASA Technical Reports Server (NTRS)

    Phillips, W. M.; Stearns, J. W.

    1985-01-01

    The use of solar thermal power systems coupled with thermal energy storage (TES) is being studied for both terrestrial and space applications. In the case of terrestrial applications, it was found that one or two hours of TES could shift the insolation peak (solar noon) to coincide with user peak loads. The use of a phase change material (PCM) is attractive because of the higher energy storage density which can be achieved. However, the use of PCM has also certain disadvantages which must be addressed. Proof of concept testing was undertaken to evaluate corrosive effects and thermal ratcheting effects in a slurry system. It is concluded that the considered alkali metal/alkali salt slurry approach to TES appears to be very viable, taking into account an elimination of thermal ratcheting in storage systems and the reduction of corrosive effects. The approach appears to be useful for an employment involving temperatures applicable to Brayton or Stirling cycles.

  5. In-Plant Testing of High-Efficiency Hydraulic Separators

    SciTech Connect

    G. H. Luttrell; R. Q. Honaker; R. C. Bratton; T. C. Westerfield; J. N. Kohmuench

    2004-07-20

    The mineral processing industry has commonly utilized hydraulic separators throughout history for classification and gravity concentration of various minerals. More commonly referred to as hindered-bed or fluidized-bed separators, these units make use of differential particle settling rates to segregate particles according to shape, size, and/or density. As with any equipment, there are inefficiencies associated with its operation, which prompted an industry driven research program to further evaluate two novel high-efficiency hindered bed separators. These units, which are commercially called the CrossFlow separator and HydroFloat separator, have the potential to improve performance (separation efficiency and throughput) and reduce operating costs (power consumption, water and reagent usage). This report describes the results of Phase I activities (laboratory and pilot-scale tests) conducted with the CrossFlow and HydroFloat separators at several locations in the minerals and coal industries. Details of the testing programs (equipment setup, shakedown testing and detailed testing) associated with four coal plants and two phosphate plants are summarized in this work. In most of these applications, the high-efficiency units proved to provide a higher quality product at reduced costs when compared against the performance of conventional separators. Based on promising results obtained from Phase I, full-scale prototypes will be purchased by several mining companies for use in Phase II of this project. Two of the prototype units, which will be constructed by Eriez Manufacturing, are expected to be installed by a major U.S. phosphate producer and a large eastern U.S. coal company. Negotiations are also underway to purchase and install additional prototype units by a mineral sands producer and a second phosphate producer. The data obtained from the full-scale evaluations will be used to further promote commercialization and industrial applications of these innovative

  6. Methodologies for high efficiency perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Park, Nam-Gyu

    2016-06-01

    Since the report on long-term durable solid-state perovskite solar cell in 2012, perovskite solar cells based on lead halide perovskites having organic cations such as methylammonium CH3NH3PbI3 or formamidinium HC(NH2)2PbI3 have received great attention because of superb photovoltaic performance with power conversion efficiency exceeding 22 %. In this review, emergence of perovskite solar cell is briefly introduced. Since understanding fundamentals of light absorbers is directly related to their photovoltaic performance, opto-electronic properties of organo lead halide perovskites are investigated in order to provide insight into design of higher efficiency perovskite solar cells. Since the conversion efficiency of perovskite solar cell is found to depend significantly on perovskite film quality, methodologies for fabricating high quality perovskite films are particularly emphasized, including various solution-processes and vacuum deposition method.

  7. Methodologies for high efficiency perovskite solar cells.

    PubMed

    Park, Nam-Gyu

    2016-01-01

    Since the report on long-term durable solid-state perovskite solar cell in 2012, perovskite solar cells based on lead halide perovskites having organic cations such as methylammonium CH3NH3PbI3 or formamidinium HC(NH2)2PbI3 have received great attention because of superb photovoltaic performance with power conversion efficiency exceeding 22 %. In this review, emergence of perovskite solar cell is briefly introduced. Since understanding fundamentals of light absorbers is directly related to their photovoltaic performance, opto-electronic properties of organo lead halide perovskites are investigated in order to provide insight into design of higher efficiency perovskite solar cells. Since the conversion efficiency of perovskite solar cell is found to depend significantly on perovskite film quality, methodologies for fabricating high quality perovskite films are particularly emphasized, including various solution-processes and vacuum deposition method.

  8. New type of transformerless high efficiency inverter

    NASA Astrophysics Data System (ADS)

    Naaijer, G. J.

    Inverter architectures are presented which allow economical ac/dc switching for solar cell array and battery power use in domestic and industrial applications. The efficiencies of currently available inverters are examined and compared with a new 2.2 kW transformerless stepped wave inverter. The inverter has low no-load losses, amounting to 200 Wh/24 hr, and features voltage steps occurring 15-30 times/sine wave period. An example is provided for an array/battery/inverter assembly with the inverter control electronics activating or disconnecting the battery subassemblies based on the total number of activated subassemblies in relation to a reference sinewave, and the need to average the battery subassembly discharge rates. A total harmonic distortion of 6 percent was observed, and the system is noted to be usable as a battery charger.

  9. High efficiency porphyrin sensitized mesoscopic solar cells

    NASA Astrophysics Data System (ADS)

    Giordano, Fabrizio; Yi, Chenyi; Teuscher, Joël.; Zakeeruddin, Shaik M.; Grätzel, Michael

    2014-10-01

    Dye-Sensitized Solar Cells (DSSC) represents a reliable technology, ready for the market and able to compete with silicon solar cells for specific fields of application. Porphyrin dyes allow reaching high power conversion efficiency in conjunction with cobalt redox electrolytes due to larger open circuit potentials. The bigger size of the cobalt complexes compared to standard iodide/triiodide redox couple hampers its percolation through the meso-porous TiO2 network, thus impairing the regeneration process. In case of porphyrin dyes mass transport problems in the electrolyte need to be carefully handled, due to the large size of the sensitizing molecule and the bulky cobalt complexes. Herein we report the study of structural variations on porphyrin sensitizers and their influence on the DSSC performance with cobalt based redox electrolyte.

  10. High-efficiency thermoelectrics with functionalized graphene.

    PubMed

    Kim, Jeong Yun; Grossman, Jeffrey C

    2015-05-13

    Graphene superlattices made with chemical functionalization offer the possibility of tuning both the thermal and electronic properties via nanopatterning of the graphene surface. Using classical and quantum mechanical calculations, we predict that suitable chemical functionalization of graphene can introduce peaks in the density of states at the band edge that result in a large enhancement in the Seebeck coefficient, leading to an increase in the room-temperature power factor of a factor of 2 compared to pristine graphene, despite the degraded electrical conductivity. Furthermore, the presence of patterns on graphene reduces the thermal conductivity, which when taken together leads to an increase in the figure of merit for functionalized graphene by up to 2 orders of magnitude over that of pristine graphene, reaching its maximum ZT ∼ 3 at room temperature according to our calculations. These results suggest that appropriate chemical functionalization could lead to efficient graphene-based thermoelectric materials.

  11. Highly efficient fully transparent inverted OLEDs

    NASA Astrophysics Data System (ADS)

    Meyer, J.; Winkler, T.; Hamwi, S.; Schmale, S.; Kröger, M.; Görrn, P.; Johannes, H.-H.; Riedl, T.; Lang, E.; Becker, D.; Dobbertin, T.; Kowalsky, W.

    2007-09-01

    One of the unique selling propositions of OLEDs is their potential to realize highly transparent devices over the visible spectrum. This is because organic semiconductors provide a large Stokes-Shift and low intrinsic absorption losses. Hence, new areas of applications for displays and ambient lighting become accessible, for instance, the integration of OLEDs into the windshield or the ceiling of automobiles. The main challenge in the realization of fully transparent devices is the deposition of the top electrode. ITO is commonly used as transparent bottom anode in a conventional OLED. To obtain uniform light emission over the entire viewing angle and a low series resistance, a TCO such as ITO is desirable as top contact as well. However, sputter deposition of ITO on top of organic layers causes damage induced by high energetic particles and UV radiation. We have found an efficient process to protect the organic layers against the ITO rf magnetron deposition process of ITO for an inverted OLED (IOLED). The inverted structure allows the integration of OLEDs in more powerful n-channel transistors used in active matrix backplanes. Employing the green electrophosphorescent material Ir(ppy) 3 lead to IOLED with a current efficiency of 50 cd/A and power efficiency of 24 lm/W at 100 cd/m2. The average transmittance exceeds 80 % in the visible region. The on-set voltage for light emission is lower than 3 V. In addition, by vertical stacking we achieved a very high current efficiency of more than 70 cd/A for transparent IOLED.

  12. A High Efficiency Grazing Incidence Pumped X-ray Laser

    SciTech Connect

    Dunn, J; Keenan, R; Price, D F; Patel, P K; Smith, R F; Shlyaptsev, V N

    2006-08-31

    The main objective of the project is to demonstrate a proof-of-principle, new type of high efficiency, short wavelength x-ray laser source that will operate at unprecedented high repetition rates (10Hz) that could be scaled to 1kHz or higher. The development of a high average power, tabletop x-ray laser would serve to complement the wavelength range of 3rd and future 4th generation light sources, e.g. the LCLS, being developed by DOE-Basic Energy Sciences. The latter are large, expensive, central, synchrotron-based facilities while the tabletop x-ray laser is compact, high-power laser-driven, and relatively inexpensive. The demonstration of such a unique, ultra-fast source would allow us to attract funding from DOE-BES, NSF and other agencies to pursue probing of diverse materials undergoing ultrafast changes. Secondly, this capability would have a profound impact on the semiconductor industry since a coherent x-ray laser source would be ideal for ''at wavelength'' {approx}13 nm metrology and microscopy of optics and masks used in EUV lithography. The project has major technical challenges. We will perform grazing-incidence pumped laser-plasma experiments in flat or groove targets which are required to improve the pumping efficiency by ten times. Plasma density characterization using our existing unique picosecond x-ray laser interferometry of laser-irradiated targets is necessary. Simulations of optical laser propagation as well as x-ray laser production and propagation through freely expanding and confined plasma geometries are essential. The research would be conducted using the Physics Directorate Callisto and COMET high power lasers. At the end of the project, we expect to have a high-efficiency x-ray laser scheme operating below 20 nm at 10Hz with a pulse duration of {approx}2 ps. This will represent the state-of-the-art in x-ray lasers and would be a major step forward from our present picosecond laser-driven x-ray lasers. There is an added bonus of creating

  13. PowerPlex® Fusion 6C System: evaluation study for analysis of casework and database samples

    PubMed Central

    Cisana, Selena; Cerri, Nicoletta; Bosetti, Alessandro; Verzeletti, Andrea; Cortellini, Venusia

    2017-01-01

    Aim To report on the successful analysis of amplicons obtained with PowerPlex® Fusion 6C System, a highly robust 27-plex genotyping kit developed for human identification laboratories, on the Applied Biosystems® 3500 Genetic Analyzer. Method We performed characterization and evaluation studies following the Scientific Working Group on DNA Analysis Methods (SWGDAM) validation guidelines, examining several critical areas of kit performance. We report the results of sensitivity, robustness, heterozygous peak height ratio, precision, concordance, caseworks, and mixture interpretations. We tested sensitivity, using serial dilutions of control DNA. Results The minimum amount of input DNA resulting in a full profile was 125 pg. Inhibition, inducted by urea, showed a progressively fragmentation of DNA and a full profile was obtained until 1M of inhibitor factor. To test the profile quality, casework samples were extracted with different extraction methods: Chelex®100, QIAmp DNA Micro Kit and Phenol-Chloroform extraction. The results demonstrated that extraction chemistries do not have affect on amplification performance. Concordance check was performed by typing some casework samples and comparing the typing results with those obtained with other available kits. Thus, concordance was expected and supported by the data. Conclusion Reliable DNA typing results can be obtained using this new kit, demonstrating its effectiveness and utility in forensic analysis. PMID:28252872

  14. Population data of 23 STR loci (PowerPlex® Fusion System) in Mexican Mestizos from the West Region.

    PubMed

    Aguilar-Velázquez, J A; Martínez-Cortés, G; Inclán-Sánchez, A; Romero-Rentería, O; Díaz-Navarro, X X; Rangel-Villalobos, H

    2016-11-01

    We analyzed 238 unrelated Mestizo (admixed) individuals from the West region of Mexico with the PowerPlex® Fusion System (Promega Corp.). Allele frequencies and forensic parameters were estimated for the 23 STRs included in this kit. Hardy-Weinberg equilibrium by locus and non-association between pair of loci were demonstrated by exact tests in this population. The combined PE and PD offered by this HID kit were ≥0.9999999986, representing a substantial improvement with respect to those previously offered by 15 STR systems. Interpopulation comparison by AMOVA tests demonstrated low but significant differences among Mexican Mestizos from West, Center, and Northeast regions (Fst = 0.01558; p = 0.0000), similar to the observed among three main ethnic groups from USA (Fst = 0.02048; p = 0.0000). This finding is consistent with the contrary clines of European and Amerindian ancestries described throughout the Mexican territory for Mestizos, the largest population (~90 %) in this country.

  15. The design of a multimegawatt heat pipe radiator for an inertial fusion rocket powered manned Mars mission

    NASA Technical Reports Server (NTRS)

    Murray, K. A.

    1988-01-01

    A system of heat pipe radiators has been designed to provide waste heat rejection for an inertial fusion powered spacecraft capable of manned missions to other planets. The radiators are arrays of unfinned, arterial heat pipes operating at 1500 and 900 K. Liquid metal coolant carries up to 8000 MW of waste heat through feed pipes from on-board components (laser drivers and coil shield). The radiators do not rely on armor for protection from micrometeoroid penetration. An armored radiator design for this application with a 99 percent survivability would have a specific mass of 0.06 to 0.11 kg/kW at 1500 K. Instead, a segmentation of heat pipes is used, and bumpers are utilized to protect the feed pipes. This design reduces the specific mass to 0.015 to 0.04 kg/kW for the coil shield radiator (1500 K) and 0.06 to 0.12 kg/kW for the laser driver radiator (900 K).

  16. Laser or charged-particle-beam fusion reactor with direct electric generation by magnetic flux compression

    DOEpatents

    Lasche, George P.

    1988-01-01

    A high-power-density laser or charged-particle-beam fusion reactor system maximizes the directed kinetic energy imparted to a large mass of liquid lithium by a centrally located fusion target. A fusion target is embedded in a large mass of lithium, of sufficient radius to act as a tritium breeding blanket, and provided with ports for the access of beam energy to implode the target. The directed kinetic energy is converted directly to electricity with high efficiency by work done against a pulsed magnetic field applied exterior to the lithium. Because the system maximizes the blanket thickness per unit volume of lithium, neutron-induced radioactivities in the reaction chamber wall are several orders of magnitude less than is typical of other fusion reactor systems.

  17. Laser or charged-particle-beam fusion reactor with direct electric generation by magnetic flux compression

    DOEpatents

    Lasche, G.P.

    1987-02-20

    A high-power-density-laser or charged-particle-beam fusion reactor system maximizes the directed kinetic energy imparted to a large mass of liquid lithium by a centrally located fusion target. A fusion target is embedded in a large mass of lithium, of sufficient radius to act as a tritium breeding blanket, and provided with ports for the access of beam energy to implode the target. The directed kinetic energy is converted directly to electricity with high efficiency by work done against a pulsed magnetic field applied exterior to the lithium. Because the system maximizes the blanket thickness per unit volume of lithium, neutron-induced radioactivities in the reaction chamber wall are several orders of magnitude less than is typical of other fusion reactor systems. 25 figs.

  18. The science program of the TCV tokamak: exploring fusion reactor and power plant concepts

    NASA Astrophysics Data System (ADS)

    Coda, S.; TCV Team

    2015-10-01

    TCV is acquiring a new 1 MW neutral beam and 2 MW additional third-harmonic electron cyclotron resonance heating (ECRH) to expand its operational range. Its existing shaping and ECRH launching versatility was amply exploited in an eclectic 2013 campaign. A new sub-ms real-time equilibrium reconstruction code was used in ECRH control of NTMs and in a prototype shape controller. The detection of visible light from the plasma boundary was also successfully used in a position-control algorithm. A new bang-bang controller improved stability against vertical displacements. The RAPTOR real-time transport simulator was employed to control the current density profile using electron cyclotron current drive. Shot-by-shot internal inductance optimization was demonstrated by iterative learning control of the current reference trace. Systematic studies of suprathermal electrons and ions in the presence of ECRH were performed. The L-H threshold power was measured to be ˜50-75% higher in both H and He than D, to increase with the length of the outer separatrix, and to be independent of the current ramp rate. Core turbulence was found to decrease from positive to negative edge triangularity deep into the core. The geodesic acoustic mode was studied with multiple diagnostics, and its axisymmetry was confirmed by a full toroidal mapping of its magnetic component. A new theory predicting a toroidal rotation component at the plasma edge, driven by inhomogeneous transport and geodesic curvature, was tested successfully. A new high-confinement mode (IN-mode) was found with an edge barrier in density but not in temperature. The edge gradients were found to govern the scaling of confinement with current, power, density and triangularity. The dynamical interplay of confinement and magnetohydrodynamic modes leading to the density limit in TCV was documented. The heat flux profile decay lengths and heat load profile on the wall were documented in limited plasmas. In the snowflake (SF

  19. Multi-wavelength high efficiency laser system for lidar applications

    NASA Astrophysics Data System (ADS)

    Willis, Christina C. C.; Culpepper, Charles; Burnham, Ralph

    2015-09-01

    Motivated by the growing need for more efficient, high output power laser transmitters, we demonstrate a multi-wavelength laser system for lidar-based applications. The demonstration is performed in two stages, proving energy scaling and nonlinear conversion independently for later combination. Energy scaling is demonstrated using a 1064 nm MOPA system which employs two novel ceramic Nd:YAG slab amplifiers, the structure of which is designed to improve the amplifier's thermal performance and energy extraction via three progressive doping stages. This structure improved the extraction efficiency by 19% over previous single-stage dopant designs. A maximum energy of 34 mJ was produced at 500 Hz with a 10.8 ns pulse duration. High efficiency non-linear conversion from 1064 nm to 452 nm is demonstrated using a KTP ring OPO with a BBO intra-cavity doubler pumped with 50 Hz, 16 ns 1064 nm pulses. The OPO generates 1571 nm signal which is frequency doubled to 756 nm by the BBO. Output 786 nm pulses are mixed with the 1064 nm pump pulses to generate 452 nm. A conversion efficiency of 17.1% was achieved, generating 3 mJ of 452 nm pulses of 7.8 ns duration. Pump power was limited by intra-cavity damage thresholds, and in future experiments we anticipate >20% conversion efficiency.

  20. High efficient solar tracker based on a simple shutter structure

    NASA Astrophysics Data System (ADS)

    Chen, Jin-Jia; Liu, Te-Shu; Huang, Kuang-Lung; Lin, Po-Chih

    2013-09-01

    In many photovoltaic (PV) or sunlight-illumination systems, solar trackers are always essential to obtain high energy/flux concentration efficiency, and that would lead to increase cost and extra power consumption due to the complex structure and heavy weight of the trackers. To decrease the cost while without sacrificing efficiency, a Fresnellens concentrator incorporated with a simple and cheap shutter, which consists of high reflective mirrors instead of conventional trackers, is proposed in this paper to provide solar tracking during the daytime. Thus, the time-variant and slant-incident sunlight rays can be redirected to vertically incident upon the surface of the Fresnel lens by appropriately arranging mirrors and swinging them to the proper slant angles with respect to the orientation of sunlight. The computer simulation results show that power concentration efficiency over 90%, as compared with the efficiency of directly normal incident sunlight, can be achieved with the mirror reflectance of 0.97 and for any solar incident angle within +/-75 degrees to the normal of the Fresnel lens. To verify the feasibility and performance of the concentrator with the proposed shutter, a sunlight illumination system based on this novel structure is demonstrated. Both computer simulation and practical measurement results for the prototype of the sunlight illumination system are also given to compare with. The results prove the simple and high efficient shutter applicable to general PV or sunlight-illumination systems for solar tracking.

  1. The design of space optical communications terminal with high efficient

    NASA Astrophysics Data System (ADS)

    Deng, Xiaoguo; Li, Gang; Jiang, Bo; Yang, Xiaoxu; Yan, Peipei

    2015-02-01

    In order to improve high-speed laser space optical communications terminal receive energy and emission energy, meet the demand of mini-type and light-type for space-based bear platform, based on multiple-reflect coaxial optical receiving antenna structure, while considering the installation difficulty, a high-efficient optical system had been designed, which aperture is off-axial, both signal-receiving sub-optical system and emission sub-optical system share a same primary optical path. By the separating light lens behind the primary optical path, the received light with little energy will be filtered and shaped and then transmitted to each detector, at the same time, by the coupling element, the high-power laser will be coupling into optical antenna, and then emitted to outside. Applied the power-detected optical system evaluate principle, the optimized off-axial optical system's efficiency had been compared with the coaxial optical system. While, analyzed the Gauss beam energy distribution by numerical theory, discussed that whether off-axis optical system can be an emission terminal, verify the feasibility of the theory of the design of the system.

  2. A high efficiency hybrid stirling-pulse tube cryocooler

    NASA Astrophysics Data System (ADS)

    Wang, Xiaotao; Zhang, Yibing; Li, Haibing; Dai, Wei; Chen, Shuai; Lei, Gang; Luo, Ercang

    2015-03-01

    This article presented a hybrid cryocooler which combines the room temperature displacers and the pulse tube in one system. Compared with a traditional pulse tube cryocooler, the system uses the rod-less ambient displacer to recover the expansion work from the pulse tube cold end to improve the efficiency while still keeps the advantage of the pulse tube cryocooler with no moving parts at the cold region. In the meantime, dual-opposed configurations for both the compression pistons and displacers reduce the cooler vibration to a very low level. In the experiments, a lowest no-load temperature of 38.5 K has been obtained and the cooling power at 80K was 26.4 W with an input electric power of 290 W. This leads to an efficiency of 24.2% of Carnot, marginally higher than that of an ordinary pulse tube cryocooler. The hybrid configuration herein provides a very competitive option when a high efficiency, high-reliability and robust cryocooler is desired.

  3. High efficiency pulse tube cryocoolers for aerospace applications

    NASA Astrophysics Data System (ADS)

    Dang, Haizheng

    2014-01-01

    This paper reviews the recent advances in Stirling-type pulse tube cryocoolers for aerospace applications in the author's group. Due to the special environment featuring the limited power supply and adverse rejection condition, high cooler efficiencies are emphasized and thus the approaches to realize them are stressed. The cold fingers involve three geometries, and designs and optimizations on key dimensional parameters of coaxial and in-line ones for given compressors are discussed and compared. The high performance moving-coil linear compressors are studied, and the optimizations on linear motor and flexure springs are briefly reviewed as examples of studies on the key compressor technologies. The mature single-stage coolers cover 25-200 K with the capacities varying from milliwatt levels to over 30 W, and the high efficiencies at typical temperatures such as 40 K, 60 K, 80 K and 95 K are presented. The two-stage arrangement is becoming another trend to achieve cooling below 25 K and also to simultaneously provide cooling powers at both stages. Some typical development programs are introduced and a brief overview of the data package is updated.

  4. Highly Efficient Thermostable DSM Cellulases: Why & How?

    SciTech Connect

    Kumar, Manoj

    2011-04-26

    These are the slides from this presentation. Lignocellulosic biomass is the most abundant, least expensive renewable natural biological resource for the production of biobased products and bioenergy is important for the sustainable development of human civilization in 21st century. For making the fermentable sugars from lignocellulosic biomass, a reduction in cellulase production cost, an improvement in cellulase performance, and an increase in sugar yields are all vital to reduce the processing costs of biorefineries. Improvements in specific cellulase activities for non-complexed cellulase mixtures can be implemented through cellulase engineering based on rational design or directed evolution for each cellulase component enzyme, as well as on the reconstitution of cellulase components. In this paper, we will provide DSM's efforts in cellulase research and developments and focus on limitations. Cellulase improvement strategies based on directed evolution using screening on relevant substrates, screening for higher thermal tolerance based on activity screening approaches such as continuous culture using insoluble cellulosic substrates as a powerful selection tool for enriching beneficial cellulase mutants from the large library. We will illustrate why and how thermostable cellulases are vital for economic delivery of bioproducts from cellulosic biomass using biochemical conversion approach.

  5. Vacuum MOCVD fabrication of high efficience cells

    NASA Technical Reports Server (NTRS)

    Partain, L. D.; Fraas, L. M.; Mcleod, P. S.; Cape, J. A.

    1985-01-01

    Vacuum metal-organic-chemical-vapor-deposition (MOCVD) is a new fabrication process with improved safety and easier scalability due to its metal rather than glass construction and its uniform multiport gas injection system. It uses source materials more efficiently than other methods because the vacuum molecular flow conditions allow the high sticking coefficient reactants to reach the substrates as undeflected molecular beams and the hot chamber walls cause the low sticking coefficient reactants to bounce off the walls and interact with the substrates many times. This high source utilization reduces the materials costs power device and substantially decreases the amounts of toxic materials that must be handled as process effluents. The molecular beams allow precise growth control. With improved source purifications, vacuum MOCVD has provided p GaAs layers with 10-micron minority carrier diffusion lengths and GaAs and GaAsSb solar cells with 20% AMO efficiencies at 59X and 99X sunlight concentration ratios. Mechanical stacking has been identified as the quickest, most direct and logical path to stacked multiple-junction solar cells that perform better than the best single-junction devices. The mechanical stack is configured for immediate use in solar arrays and allows interconnections that improve the system end-of-life performance in space.

  6. Biologically inspired highly efficient buoyancy engine

    NASA Astrophysics Data System (ADS)

    Akle, Barbar; Habchi, Wassim; Abdelnour, Rita; Blottman, John, III; Leo, Donald

    2012-04-01

    Undersea distributed networked sensor systems require a miniaturization of platforms and a means of both spatial and temporal persistence. One aspect of this system is the necessity to modulate sensor depth for optimal positioning and station-keeping. Current approaches involve pneumatic bladders or electrolysis; both require mechanical subsystems and consume significant power. These are not suitable for the miniaturization of sensor platforms. Presented in this study is a novel biologically inspired method that relies on ionic motion and osmotic pressures to displace a volume of water from the ocean into and out of the proposed buoyancy engine. At a constant device volume, the displaced water will alter buoyancy leading to either sinking or floating. The engine is composed of an enclosure sided on the ocean's end by a Nafion ionomer and by a flexible membrane separating the water from a gas enclosure. Two electrodes are placed one inside the enclosure and the other attached to the engine on the outside. The semi-permeable membrane Nafion allows water motion in and out of the enclosure while blocking anions from being transferred. The two electrodes generate local concentration changes of ions upon the application of an electrical field; these changes lead to osmotic pressures and hence the transfer of water through the semi-permeable membrane. Some aquatic organisms such as pelagic crustacean perform this buoyancy control using an exchange of ions through their tissue to modulate its density relative to the ambient sea water. In this paper, the authors provide an experimental proof of concept of this buoyancy engine. The efficiency of changing the engine's buoyancy is calculated and optimized as a function of electrode surface area. For example electrodes made of a 3mm diameter Ag/AgCl proved to transfer approximately 4mm3 of water consuming 4 Joules of electrical energy. The speed of displacement is optimized as a function of the surface area of the Nafion

  7. High efficiency radioisotope thermophotovoltaic prototype generator

    NASA Technical Reports Server (NTRS)

    Avery, James E.; Samaras, John E.; Fraas, Lewis M.; Ewell, Richard

    1995-01-01

    A radioisotope thermophotovoltaic generator space power system (RTPV) is lightweight, low-cost alternative to the present radioisotope thermoelectric generator system (RTG). The fabrication of such an RTPV generator has recently become feasible as the result of the invention of the GaSb infrared sensitive photovoltaic cell. Herein, we present the results of a parametric study of emitters and optical filters in conjuction with existing data on gallium antimonide cells. We compare a polished tungsten emitter with an Erbia selective emitter for use in combination with a simple dielectric filter and a gallium antimonide cell array. We find that the polished tungsten emitter is by itself a very selective emitter with low emissivity beyond 4 microns. Given a gallium antimonide cell and a tungsten emitter, a simple dielectric filter can be designed to transmit radiant energy below 1.7 microns and to reflect radiant energy between 1.7 and 4 microns back to the emitter. Because of the low long wavelength emissivity associated with the polished tungsten emitter, this simple dielectric filter then yields very respectable system performance. Also as a result of the longer wavelength fall-off in the tungsten emissivity curve, the radiation energy peak for a polished tungsten emitter operating at 1300 K shifts to shorter wavelengths relative to the blackbody spectrum so that the radiated energy peak falls right at the gallium antimonide cell bandedge. The result is that the response of the gallium antimonide cell is well matched to a polished tungsten emitter. We propose, therefore, to fabricate an operating prototype of a near term radioisotope thermophotovoltaic generator design consisting of a polished tungsten emitter, standard gallium antimonide cells, and a near-term dielectric filter. The Jet Propulsion Laboratory will design and build the thermal cavity, and JX Crystals will fabricate the gallium antimonide cells, dielectric filters, and resultant receiver panels. With

  8. A framework for predicting the yield stress, Charpy toughness and one hundred-year activation level for irradiated fusion power plant alloys

    NASA Astrophysics Data System (ADS)

    Windsor, Colin; Cottrell, Geoff; Kemp, Richard

    2011-04-01

    Recent papers have demonstrated that the yield stress and the Charpy ductile to brittle transition temperature shift at the high irradiation levels of a fusion power plant may be predicted from measurements at lower irradiation levels using neural networks. It was demonstrated that the extrapolation inherent in such predictions could be validated provided that network complexity was appropriately low. Simultaneous predictions of these metallurgical properties at the 100 dpa irradiation level and 400 °C irradiation temperature of a possible fusion power plant have been made for a series of ferritic/martensitic steels, albeit based on mainly fission data. Together with the readily available one hundred-year activation level, benefit functions are defined which can be used to predict the most suitable alloys for a fusion power plant from within existing databases. Our model is sufficiently flexible to allow a variety of possible benefit functions to be defined. The F82H, Eurofer and LA12 alloy series all receive a favourable rating, although all results presented here must be tempered with caution until more data at relevant irradiation levels and with relevant energy spectra become available.

  9. Developmental validation of the PowerPlex(®) Fusion System for analysis of casework and reference samples: A 24-locus multiplex for new database standards.

    PubMed

    Oostdik, Kathryn; Lenz, Kristy; Nye, Jeffrey; Schelling, Kristin; Yet, Donald; Bruski, Scott; Strong, Joshua; Buchanan, Clint; Sutton, Joel; Linner, Jessica; Frazier, Nicole; Young, Hays; Matthies, Learden; Sage, Amber; Hahn, Jeff; Wells, Regina; Williams, Natasha; Price, Monica; Koehler, Jody; Staples, Melisa; Swango, Katie L; Hill, Carolyn; Oyerly, Karen; Duke, Wendy; Katzilierakis, Lesley; Ensenberger, Martin G; Bourdeau, Jeanne M; Sprecher, Cynthia J; Krenke, Benjamin; Storts, Douglas R

    2014-09-01

    The original CODIS database based on 13 core STR loci has been overwhelmingly successful for matching suspects with evidence. Yet there remain situations that argue for inclusion of more loci and increased discrimination. The PowerPlex(®) Fusion System allows simultaneous amplification of the following loci: Amelogenin, D3S1358, D1S1656, D2S441, D10S1248, D13S317, Penta E, D16S539, D18S51, D2S1338, CSF1PO, Penta D, TH01, vWA, D21S11, D7S820, D5S818, TPOX, DYS391, D8S1179, D12S391, D19S433, FGA, and D22S1045. The comprehensive list of loci amplified by the system generates a profile compatible with databases based on either the expanded CODIS or European Standard Set (ESS) requirements. Developmental validation testing followed SWGDAM guidelines and demonstrated the quality and robustness of the PowerPlex(®) Fusion System across a number of variables. Consistent and high-quality results were compiled using data from 12 separate forensic and research laboratories. The results verify that the PowerPlex(®) Fusion System is a robust and reliable STR-typing multiplex suitable for human identification.

  10. The mechanism of burn-in loss in a high efficiency polymer solar cell.

    PubMed

    Peters, Craig H; Sachs-Quintana, I T; Mateker, William R; Heumueller, Thomas; Rivnay, Jonathan; Noriega, Rodigo; Beiley, Zach M; Hoke, Eric T; Salleo, Alberto; McGehee, Michael D

    2012-02-02

    Degradation in a high efficiency polymer solar cell is caused by the formation of states in the bandgap. These states increase the energetic disorder in the system. The power conversion efficiency loss does not occur when current is run through the device in the dark but occurs when the active layer is photo-excited.

  11. 40 CFR 761.71 - High efficiency boilers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false High efficiency boilers. 761.71... PROHIBITIONS Storage and Disposal § 761.71 High efficiency boilers. (a) To burn mineral oil dielectric fluid containing a PCB concentration of ≥50 ppm, but boiler shall comply with the...

  12. 40 CFR 761.71 - High efficiency boilers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false High efficiency boilers. 761.71... PROHIBITIONS Storage and Disposal § 761.71 High efficiency boilers. (a) To burn mineral oil dielectric fluid containing a PCB concentration of ≥50 ppm, but boiler shall comply with the...

  13. 40 CFR 761.71 - High efficiency boilers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false High efficiency boilers. 761.71... PROHIBITIONS Storage and Disposal § 761.71 High efficiency boilers. (a) To burn mineral oil dielectric fluid containing a PCB concentration of ≥50 ppm, but boiler shall comply with the...

  14. 40 CFR 761.71 - High efficiency boilers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false High efficiency boilers. 761.71... PROHIBITIONS Storage and Disposal § 761.71 High efficiency boilers. (a) To burn mineral oil dielectric fluid containing a PCB concentration of ≥50 ppm, but boiler shall comply with the...

  15. High efficiency low cost GaAs/Ge cell technology

    NASA Technical Reports Server (NTRS)

    Ho, Frank

    1990-01-01

    Viewgraphs on high efficiency low cost GaAs/Ge cell technology are presented. Topics covered include: high efficiency, low cost GaAs/Ge solar cells; advantages of Ge; comparison of typical production cells for space applications; panel level comparisons; and solar cell technology trends.

  16. HIGH EFFICIENCY DESULFURIZATION OF SYNTHESIS GAS

    SciTech Connect

    Kwang-Bok Yi; Anirban Mukherjee; Elizabeth J. Podlaha; Douglas P. Harrison

    2004-03-01

    reducing gases for extended time periods. H{sub 2}S concentrations were reduced to levels approaching the minimum detectable limit of the PFPD detector, approximately 100 ppbv for time periods corresponding to as much as 60% sorbent sulfidation. The critical test of the sorbents was their performance when the reducing power of the feed gas was decreased by the addition of CO{sub 2} as an oxidant. While sub-ppmv levels of H{sub 2}S were still achieved using both CeO{sub 2} and CeO{sub 2}-ZrO{sub 2} sorbents when the feed gas contained as much as 1% CO{sub 2}, the duration of the prebreakthrough time decreased as the CO{sub 2} concentration increased.

  17. Particle beam fusion

    SciTech Connect

    1980-12-31

    Today, in keeping with Sandia Laboratories` designation by the Department of Energy as the lead laboratory for the pulsed power approach to fusion, its efforts include major research activities and the construction of new facilities at its Albuquerque site. Additionally, in its capacity as lead laboratory, Sandia coordinates DOE-supported pulsed power fusion work at other government operated laboratories, with industrial contractors, and universities. The beginning of Sandia`s involvement in developing fusion power was an outgrowth of its contributions to the nation`s nuclear weapon program. The Laboratories` work in the early 1960`s emphasized the use of pulsed radiation environments to test the resistance of US nuclear weapons to enemy nuclear bursts. A careful study of options for fusion power indicated that Sandia`s expertise in the pulsed power field could provide a powerful match to ignite fusion fuel. Although creating test environments is an achieved goal of Sandia`s overall program, this work and other military tasks protected by appropriate security regulations will continue, making full use of the same pulsed power technology and accelerators as the fusion-for-energy program. Major goals of Sandia`s fusion program including the following: (1) complete a particle accelerator to deliver sufficient beam energy for igniting fusion targets; (2) obtain net energy gain, this goal would provide fusion energy output in excess of energy stored in the accelerator; (3) develop a technology base for the repetitive ignition of pellets in a power reactor. After accomplishing these goals, the technology will be introduced to the nation`s commercial sector.

  18. IN-PLANT TESTING OF HIGH-EFFICIENCY HYDRAULIC SEPARATORS

    SciTech Connect

    G.H. Luttrell; R.Q. Honaker; R.C. Bratton; T.C. Westerfield; J.N. Kohmuench

    2006-05-22

    Hydraulic separators are commonly used for particle size classification and gravity concentration of minerals and coal. Unfortunately, the efficiency of these processes can be quite low due to poor equipment design and variations in feed consistency. To help alleviate these problems, an industry-driven R&D program has been undertaken to develop a new generation of hydraulic separators that are more efficient and less costly to operate and maintain. These units, which are commercially called the CrossFlow separator and HydroFloat separator, have the potential to improve performance (separation efficiency and throughput) and reduce operating costs (power consumption, water and reagent usage). In Phase I of this project, laboratory and pilot-scale test units were evaluated at various industrial sites in both the coal and mineral industries. Based on promising results obtained from Phase I, full-scale prototypes were purchased and installed by a major U.S. phosphate producer and a large eastern U.S. coal company. The test data obtained from these sites demonstrate that significant performance improvements can be realized through the application of these high-efficiency separators.

  19. In-Plant Testing of High-Efficiency Hydraulic Separators

    SciTech Connect

    G. H. Luttrell; R. Q. Honaker; R. C. Bratton; T. C. Westerfield; J. N. Kohmuench

    2006-06-30

    Hydraulic separators are commonly used for particle size classification and gravity concentration of minerals and coal. Unfortunately, the efficiency of these processes can be quite low due to poor equipment design and variations in feed consistency. To help alleviate these problems, an industry-driven R&D program has been undertaken to develop a new generation of hydraulic separators that are more efficient and less costly to operate and maintain. These units, which are commercially called the CrossFlow separator and HydroFloat separator, have the potential to improve performance (separation efficiency and throughput) and reduce operating costs (power consumption, water and reagent usage). In Phase I of this project, laboratory and pilot-scale test units were evaluated at various industrial sites in both the coal and mineral industries. Based on promising results obtained from Phase I, full-scale prototypes were purchased and installed by a major U.S. phosphate producer and a large eastern U.S. coal company. The test data obtained from these sites demonstrate that significant performance improvements can be realized through the application of these high-efficiency separators.

  20. Nonstoichiometric Adduct Approach for High-Efficiency Perovskite Solar Cells.

    PubMed

    Park, Nam-Gyu

    2017-01-03

    Since the groundbreaking report on a solid-state perovskite solar cell employing a methylammonium lead iodide-sensitized mesoporous TiO2 film and an organic hole conducting layer in 2012 by our group, the swift surge of perovskite photovoltaics opens a new paradigm in solar-cell research. As a result, ca. 1300 peer-reviewed research articles were published in 2015. In this Inorganic Chemistry Forum on Halide Perovskite, the researches with highlights of work on perovskite solar cells in my laboratory are reviewed. We have developed a size-controllable two-step spin-coating method and found that minimal nonradiative recombination in perovskite crystals could lead to high photovoltaic performance. A Lewis acid based adduct method and self-formed grain boundary process were developed for high-efficiency devices with reproducibility. A power conversion efficiency of 20.4% was achieved via grain boundary engineering based on a nonstoichiometric adduct approach. The incorporation of cesium in a formamidinium lead iodide perovskite was found to show better photostability and moisture-stability. A reduction in the dimensionality from a three-dimensitonal nanocrystal to a one-dimensional nanowire led to a hypsochromic shift of absorption and fluorescence. To enhance the charge-carrier transport and light-harvesting efficiency, a nanoarchitecture of oxide layers was proposed.

  1. A high efficiency LED driver based on optical feedback

    NASA Astrophysics Data System (ADS)

    Marti-Arbona, Edgar; Copani, Tino; Bakkaloglu, Bertan; Kiaei, Sayfe

    2014-09-01

    Light emitting diodes (LEDs) offer durability, long life, and high efficiency that make them an excellent alternative for illumination applications. The efficiency of conventional drivers suffers from losses due to the current sensing method that they employ. In this paper, the LED array itself is used as an optical sensor by periodically measuring neighboring cells' light intensity, instead of employing the commonly used series current-sense resistor. The results of this approach show that it provides accurate compensation of the LED characteristics, with less than one lumen variation in illumination, stability in color (color shift over time as low as ΔE = 0.76), and efficiency of up to 98.66%. The proposed sensor compensates for actual optical performance of the LED array and reduces aging effects compared to the approaches based in current measurement and control. The optical current-sensing method is a closed-loop feedback alternative, which improves the power efficiency of the LED driver by 3%. It maintains constant output illumination of the LED over time, and it utilizes a reduced number of components, thus extending the effective lifetime of LED-based devices.

  2. HIGH-EFFICIENCY NITRIDE-BASED SOLID-STATE LIGHTING

    SciTech Connect

    Dr. Paul T. Fini; Prof. Shuji Nakamura

    2002-09-01

    In this annual report we summarize the progress obtained in the first year with the support of DoE contract No.DE-FC26-01NT41203, entitled ''High-Efficiency Nitride-Based Solid-State Lighting''. The two teams, from the University of California at Santa Barbara (Principle Investigator: Dr. Shuji Nakamura) and Rensselaer Polytechnic Institute (led by Dr. N. Narendran), are pursuing the goals of this contract from thin film growth, characterization, and packaging standpoints. The UCSB team has made significant progress in the development of GaN vertical cavity surface-emitting lasers (VCSELs) as well as light-emitting diodes (LEDs) with AlGaN active regions emitting in the ultraviolet (UV). The Rensselaer team has developed target specifications for some of the key parameters for the proposed solid-state lighting system, including a luminous flux requirement matrix for various lighting applications, optimal spectral power distributions, and the performance characteristics of currently available commercial LEDs for eventual comparisons to the devices developed in the scope of this project.

  3. Multiple Exciton Generation for Highly Efficient Solar Cells

    NASA Astrophysics Data System (ADS)

    Nozik, Arthur

    2007-03-01

    In order to utilize solar power for the production of electricity and fuel on a massive scale, it will be necessary to develop solar photon conversion systems that have an appropriate combination of high efficiency and low capital cost (/m^2). One new potential approach to high solar cell efficiency is to utilize the unique properties of semiconductor quantum dot nanostructures to control the relaxation dynamics of photogenerated carriers to produce either enhanced photocurrent through efficient multiple exciton generation (MEG) or enhanced photopotential through hot electron transport and transfer processes. To achieve these desirable effects it is necessary to understand and control the dynamics of electron relaxation, cooling, multiple exciton generation , transport, and interfacial electron transfer of the photogenerated carriers with fs to ns time resolution. We have been studying these fundamental dynamics in bulk and nanoscale semiconductors (quantum dots, quantum wires, and quantum wells) using femtosecond transient absorption, photoluminescence, and THz spectroscopy. This work will be summarized and recent advances in creating multiple excitons from a single photon will be discussed, including a unique model to explain efficient MEG based on the coherent superposition of multiple excitonic states. Various possible configurations for quantum dot solar cells that could produce ultra-high conversion efficiencies for the production of electricity, as well as for producing solar fuels (for example, hydrogen from water splitting), will be discussed, along with associated thermodynamic calculations that show the increase in the maximum theoretical gain in solar photon conversion efficiency for both electricity and fuel production.

  4. Recent progress of Spectrolab high-efficiency space solar cells

    NASA Astrophysics Data System (ADS)

    Law, Daniel C.; Boisvert, J. C.; Rehder, E. M.; Chiu, P. T.; Mesropian, S.; Woo, R. L.; Liu, X. Q.; Hong, W. D.; Fetzer, C. M.; Singer, S. B.; Bhusari, D. M.; Edmondson, K. M.; Zakaria, A.; Jun, B.; Krut, D. D.; King, R. R.; Sharma, S. K.; Karam, N. H.

    2013-09-01

    Recent progress in III-V multijunction space solar cell has led to Spectrolab's GaInP/GaAs/Ge triple-junction, XTJ, cells with average 1-sun efficiency of 29% (AM0, 28°C) for cell size ranging from 59 to 72-cm2. High-efficiency inverted metamorphic (IMM) multijunction cells are developed as the next space solar cell architecture. Spectrolab's large-area IMM3J and IMM4J cells have achieved 33% and 34% 1-sun, AM0 efficiencies, respectively. The IMM3J and the IMM4J cells have both demonstrated normalized power retention of 0.86 at 5x1014 e-/cm2 fluence and 0.83 and 0.82 at 1x1015 e-/cm2 fluence post 1-MeV electron radiation, respectively. The IMM cells were further assembled into coverglass-interconnect-cell (CIC) strings and affixed to typical rigid aluminum honeycomb panels for thermal cycling characterization. Preliminary temperature cycling data of two coupons populated with IMM cell strings showed no performance degradation. Spectrolab has also developed semiconductor bonded technology (SBT) where highperformance component subcells were grown on GaAs and InP substrates separately then bonded directly to form the final multijunction cells. Large-area SBT 5-junction cells have achieved a 35.1% efficiency under 1-sun, AM0 condition.

  5. Tunable high-efficient pulsed NH3 terahertz lasers

    NASA Astrophysics Data System (ADS)

    Jiu, Zhi-Xian; Li, Qiang; Zuo, Du-Luo; Miao, Liang; Cheng, Zu-Hai

    2012-03-01

    Experimental studies on a tunable efficient high-efficient pulsed NH3 terahertz (THz) lasers pumped by TEA CO2 lasers are presented. When NH3 is pumped by the different lines with the CO2 lasers, the generation of different terahertz radiations is discussed. The lines of the CO2 lasers are 9R(08), 9P(20), 10R(14), 10R(08), and 10R(06). To improve THz laser energy and photon conversion efficiency, different higher power of the CO2 laser can effectively improve THz laser energy and photon conversion efficiency. When the 9P(20) CO2 lasers with 9.68 J and 4.12 J pump NH3, the corresponding energy conversion efficiencies are 0.28% and 0.19%, increasing by a factor of about 1.5. The generation of terahertz radiations with energy as high as 27.29 mJ and 7.73 mJ are obtained, respectively, increasing by a factor of about 3.5. Meanwhile, for 10R(14) line, the energy conversion efficiencies increase to 8.5 times and the energy of THz lasers increase to 32 times.

  6. Tunable high-efficient pulsed NH3 terahertz lasers

    NASA Astrophysics Data System (ADS)

    Jiu, Zhi-Xian; Li, Qiang; Zuo, Du-Luo; Miao, Liang; Cheng, Zu-Hai

    2011-11-01

    Experimental studies on a tunable efficient high-efficient pulsed NH3 terahertz (THz) lasers pumped by TEA CO2 lasers are presented. When NH3 is pumped by the different lines with the CO2 lasers, the generation of different terahertz radiations is discussed. The lines of the CO2 lasers are 9R(08), 9P(20), 10R(14), 10R(08), and 10R(06). To improve THz laser energy and photon conversion efficiency, different higher power of the CO2 laser can effectively improve THz laser energy and photon conversion efficiency. When the 9P(20) CO2 lasers with 9.68 J and 4.12 J pump NH3, the corresponding energy conversion efficiencies are 0.28% and 0.19%, increasing by a factor of about 1.5. The generation of terahertz radiations with energy as high as 27.29 mJ and 7.73 mJ are obtained, respectively, increasing by a factor of about 3.5. Meanwhile, for 10R(14) line, the energy conversion efficiencies increase to 8.5 times and the energy of THz lasers increase to 32 times.

  7. Beneficial Role of Reduced Graphene Oxide for Electron Extraction in Highly Efficient Perovskite Solar Cells.

    PubMed

    Cho, Kyung Taek; Grancini, Giulia; Lee, Yonghui; Konios, Dimitrios; Paek, Sanghyun; Kymakis, Emmanuel; Nazeeruddin, Mohammad Khaja

    2016-11-09

    In this work we systematically investigated the role of reduced graphene oxide (rGO) in hybrid perovskite solar cells (PSCs). By mixing rGO within the mesoporous TiO2 (m-TiO2 ) matrix, highly efficient solar cells with power conversion efficiency values up to 19.54 % were realized. In addition, the boosted beneficial role of rGO with and without Li-treated m-TiO2 is highlighted, improving transport and injection of photoexcited electrons. This combined system may pave the way for further development and optimization of electron transport and collection in high efficiency PSCs.

  8. High-Efficiency Flexible Solar Cells Based on Organometal Halide Perovskites.

    PubMed

    Wang, Yuming; Bai, Sai; Cheng, Lu; Wang, Nana; Wang, Jianpu; Gao, Feng; Huang, Wei

    2016-06-01

    Flexible and light-weight solar cells are important because they not only supply power to wearable and portable devices, but also reduce the transportation and installation cost of solar panels. High-efficiency organometal halide perovskite solar cells can be fabricated by a low-temperature solution process, and hence are promising for flexible-solar-cell applications. Here, the development of perovskite solar cells is briefly discussed, followed by the merits of organometal halide perovskites as promising candidates as high-efficiency, flexible, and light-weight photovoltaic materials. Afterward, recent developments of flexible solar cells based on perovskites are reviewed.

  9. Grazing incidence liquid metal mirrors (GILMM) as the final optics for laser inertial fusion energy power plants

    SciTech Connect

    Moir, R W

    1999-06-25

    A thin film of liquid metal serves as a grazing incident liquid metal mirror (GILMM) for robust final optics of an inertial fusion energy (IFE) power plant. The amount of laser light the mirror can withstand, called the damage limit, of a sodium film 85{degree} from normal arbitrarily set by surface temperature rise of 200 C to limit liquid ablation is 57 J/cm{sup 2} normal to the beam for a 20 ns pulse and 1.3 J/cm{sup 2} for a 10 ps pulse of 0.35 pm light. Liquid aluminum can handle 106 J/cm{sup 2}. The damage limit actually should be set by avoiding liquid ablation due to the rapid surface heating which is expected to result in even higher temperatures rises than 200 C and even higher power densities. The liquid surface is kept flat to the required accuracy by a combination of polished substrate, adaptive optics, surface tension and low Reynolds number, laminar flow in the film. The film's substrate must be polished to {+-}0.015 m. Then surface tension keeps the surface smooth over short distances (<10 mm) and low Reynolds number laminar flow keeps the surface smooth by keeping the film thickness constant to less than {+-} 0.01 pm over long distance >10 mm. Adaptive (deformable) optics techniques keep the substrate flat to within {+-}0.06 {micro}m over 100 mm distance and {+-}0.6 {micro}m over 1,000 mm distances. The mirror can withstand the x-ray pulse when located 30 m away from the microexplosions of nominal yield of 400 MJ (50 MJ x rays) when Li is used but for higher atomic number liquids like Na and Al there may be too high a temperature rise forcing use of other x-ray attenuation methods such as xenon gas, which may be needed for first wall protecting anyway. The cumulative damage from neutrons causing warpage of the liquid film's substrate can be compensated by adaptive optics techniques giving the mirrors long life, perhaps 30 years. The GILMM should be applicable to both direct and indirect drive and pulse lengths appropriate to slow compression

  10. Fusion for Space Propulsion

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Schafer, Charles (Technical Monitor)

    2001-01-01

    There is little doubt that humans will attempt to explore and develop the solar system in this century. A large amount of energy will be required for accomplishing this. The need for fusion propulsion is discussed. For a propulsion system, there are three important thermodynamical attributes: (1) The absolute amount of energy available, (2) the propellant exhaust velocity, and (3) the jet power per unit mass of the propulsion system (specific power). For human exploration and development of the solar system, propellant exhaust velocity in excess of 100 km/s and specific power in excess of 10 kW/kg are required. Chemical combustion can produce exhaust velocity up to about 5 km/s. Nuclear fission processes typically result in producing energy in the form of heat that needs to be manipulated at temperatures limited by materials to about 2,800 K. Using the energy to heat a hydrogen propellant increases the exhaust velocity by only a factor of about two. Alternatively the energy can be converted into electricity which is then used to accelerate particles to high exhaust velocity. The necessary power conversion and conditioning equipment, however, increases the mass of the propulsion system for the same jet power by more than two orders of magnitude over chemical system, thus greatly limits the thrust-to-weight ratio attainable. The principal advantage of the fission process is that its development is relatively mature and is available right now. If fusion can be developed, fusion appears to have the best of all worlds in terms of propulsion - it can provide the absolute amount, the propellant exhaust velocity, and the high specific jet power. An intermediate step towards pure fusion propulsion is a bimodal system in which a fission reactor is used to provide some of the energy to drive a fusion propulsion unit. The technical issues related to fusion for space propulsion are discussed. The technical priorities for developing and applying fusion for propulsion are

  11. Materials research for fusion

    NASA Astrophysics Data System (ADS)

    Knaster, J.; Moeslang, A.; Muroga, T.

    2016-05-01

    Fusion materials research started in the early 1970s following the observation of the degradation of irradiated materials used in the first commercial fission reactors. The technological challenges of fusion energy are intimately linked with the availability of suitable materials capable of reliably withstanding the extremely severe operational conditions of fusion reactors. Although fission and fusion materials exhibit common features, fusion materials research is broader. The harder mono-energetic spectrum associated with the deuterium-tritium fusion neutrons (14.1 MeV compared to <2 MeV on average for fission neutrons) releases significant amounts of hydrogen and helium as transmutation products that might lead to a (at present undetermined) degradation of structural materials after a few years of operation. Overcoming the historical lack of a fusion-relevant neutron source for materials testing is an essential pending step in fusion roadmaps. Structural materials development, together with research on functional materials capable of sustaining unprecedented power densities during plasma operation in a fusion reactor, have been the subject of decades of worldwide research efforts underpinning the present maturity of the fusion materials research programme.

  12. Evaluation of genetic parameters of 22 autosomal STR loci (PowerPlex® Fusion System) in a population sample from Northern Italy.

    PubMed

    Turrina, Stefania; Ferrian, Melissa; Caratti, Stefano; De Leo, Domenico

    2014-03-01

    The PowerPlex® Fusion System (Promega, Madison, WI) is a short tandem repeat (STR) multiplex that allows co-amplification of 22 autosomal STRs, including the CODIS core and the European Standard Set loci, plus amelogenin for gender determination and DYS391 male specific marker included in order to avoid errors in gender assignment when null Y-alleles or deletions of the Y-chromosome short arm involve the amelogenin locus. Allele frequencies and forensic efficiency parameters were estimated in a population sample of 303 unrelated healthy individuals living in Northern Italy. No significant deviations from Hardy-Weinberg expectations were observed after applying Bonferroni's correction for multiple testing. The combined power of discrimination was 0.999999999999 and the combined power of exclusion was 0.9999956. A rare 28 allele at locus D12S391 was observed, while one tri-allelic pattern at Penta E locus was detected. Population differentiation test revealed significant genetic diversity between our population sample and other European populations considered. The results showed that the PowerPlex® Fusion System is one of the most informative kit available in forensic genetics and may prove useful in both human identification and kinship analysis.

  13. High efficiency solar cell research for space applications

    NASA Technical Reports Server (NTRS)

    Flood, D. J.

    1985-01-01

    A review is given of NASA photovoltaic research with emphasis on the activities of the Lewis Research Center. High efficiency solar cell research is discussed, as well as solar arrays, multi-junction cell bandgaps, and plasmon coupling.

  14. III-V High-Efficiency Multijunction Photovoltaics (Fact Sheet)

    SciTech Connect

    Not Available

    2011-06-01

    Capabilities fact sheet that includes scope, core competencies and capabilities, and contact/web information for III-V High-Efficiency Multijunction Photovoltaics at the National Center for Photovoltaics.

  15. Development of high-efficiency solar cells on silicon web

    NASA Technical Reports Server (NTRS)

    Rohatgi, A.; Meier, D. L.; Campbell, R. B.; Seidensticker, R. G.; Rai-Choudhury, P.

    1984-01-01

    The development of high efficiency solar cells on a silicon web is discussed. Heat treatment effects on web quality; the influence of twin plane lamellae, trace impurities and stress on minority carrier lifetime; and the fabrication of cells are discussed.

  16. Grazing incidence liquid metal mirrors (GILMM) for radiation hardened final optics for laser inertial fusion energy power plants

    SciTech Connect

    Moir, R W

    1999-06-30

    A thin film of liquid metal is suggested as a grazing incident liquid metal mirror (GILMM) for robust final optics of a laser inertial fusion energy (IFE) power plant. The amount of laser light the mirror can withstand, called the damage limit, of a sodium film 85{sup o} from normal is calculated to be 57 J/cm{sup 2} normal to the beam for a 20 ns pulse and 1.3 J/cm{sup 2} for a 10 ps pulse of 0.35 {micro}m light (2 m{sup 2} and 90 m{sup 2} of mirror area per 100 kJ of laser energy at 20 ns and 10 ps, respectively). Feasibility relies on keep the liquid surface flat to the required accuracy by a combination of polished substrate, adaptive (deformable) optics, surface tension and low Reynolds number, laminar flow in the film. The film's substrate must be polished to {+-} 0.015 pm. Then surface tension keeps the surface smooth over short distances (<10 mm) and low Reynolds number laminar flow keeps the surface smooth by keeping the film thickness constant to less than + 0.01 w over long distance >10 mm. Adaptive optics techniques keep. the substrate flat to within {+-} 0.06 pm over 100 mm distance and {+-}0.6 {micro}m over 1000 mm distances. The mirror can stand the x-ray pulse when located 30 m away from the microexplosions of nominal yield of 400 MJ (50 MJ of X rays) when Li is used but for higher atomic number liquids like Na there may be too high a temperature rise forcing use of other x-ray attenuation methods such as attenuation by xenon gas. The cumulative damage from neutrons causing warpage of the liquid film's substrate can be compensated by adaptive optics techniques giving the mirrors long life, perhaps 30 years. The GILMM should be applicable to both direct and indirect drive and pulse lengths appropriate to slow compression ({approx}20 ns) or fast ignition ({approx}10 ps). For direct drive laser beams near the poles (70{sup o}, where 90{sup o} is vertical), stable thin films become more challenging. Proof of concept experiments are needed to verify the

  17. Fusion energy for space missions in the 21st Century

    NASA Technical Reports Server (NTRS)

    Schulze, Norman R.

    1991-01-01

    Future space missions were hypothesized and analyzed and the energy source for their accomplishment investigated. The mission included manned Mars, scientific outposts to and robotic sample return missions from the outer planets and asteroids, as well as fly-by and rendezvous mission with the Oort Cloud and the nearest star, Alpha Centauri. Space system parametric requirements and operational features were established. The energy means for accomplishing the High Energy Space Mission were investigated. Potential energy options which could provide the propulsion and electric power system and operational requirements were reviewed and evaluated. Fusion energy was considered to be the preferred option and was analyzed in depth. Candidate fusion fuels were evaluated based upon the energy output and neutron flux. Reactors exhibiting a highly efficient use of magnetic fields for space use while at the same time offering efficient coupling to an exhaust propellant or to a direct energy convertor for efficient electrical production were examined. Near term approaches were identified.

  18. Fusion energy for space missions in the 21st Century

    SciTech Connect

    Schulze, N.R.

    1991-08-01

    Future space missions were hypothesized and analyzed and the energy source for their accomplishment investigated. The mission included manned Mars, scientific outposts to and robotic sample return missions from the outer planets and asteroids, as well as fly-by and rendezvous mission with the Oort Cloud and the nearest star, Alpha Centauri. Space system parametric requirements and operational features were established. The energy means for accomplishing the High Energy Space Mission were investigated. Potential energy options which could provide the propulsion and electric power system and operational requirements were reviewed and evaluated. Fusion energy was considered to be the preferred option and was analyzed in depth. Candidate fusion fuels were evaluated based upon the energy output and neutron flux. Reactors exhibiting a highly efficient use of magnetic fields for space use while at the same time offering efficient coupling to an exhaust propellant or to a direct energy convertor for efficient electrical production were examined. Near term approaches were identified.

  19. High efficiency hybrid silicon nanopillar-polymer solar cells.

    PubMed

    Pudasaini, Pushpa Raj; Ruiz-Zepeda, Francisco; Sharma, Manisha; Elam, David; Ponce, Arturo; Ayon, Arturo A

    2013-10-09

    Recently, inorganic/organic hybrid solar cells have been considered as a viable alternative for low-cost photovoltaic devices because the Schottky junction between inorganic and organic materials can be formed employing low temperature processing methods. We present an efficient hybrid solar cell based on highly ordered silicon nanopillars (SiNPs) and poly(3,4-ethylene-dioxythiophene):polystyrenesulfonate (PEDOT:PSS). The proposed device is formed by spin coating the organic polymer PEDOT:PSS on a SiNP array fabricated using metal assisted electroless chemical etching process. The characteristics of the hybrid solar cells are investigated as a function of SiNP height. A maximum power conversion efficiency (PCE) of 9.65% has been achieved for an optimized SiNP array hybrid solar cell with nanopillar height of 400 nm, despite the absence of a back surface field enhancement. The effect of an ultrathin atomic layer deposition (ALD), grown aluminum oxide (Al2O3), as a passivation layer (recombination barrier) has also been studied for the enhanced electrical performance of the device. With the inclusion of the ultrathin ALD deposited Al2O3 between the SiNP array textured surface and the PEDOT:PSS layer, the PCE of the fabricated device was observed to increase to 10.56%, which is ∼10% greater than the corresponding device without the Al2O3 layer. The device described herein is considered to be promising toward the realization of a low-cost, high-efficiency inorganic/organic hybrid solar cell.

  20. High-efficiency multilayer-dielectric diffraction gratings

    SciTech Connect

    Perry, M.D.; Boyd, R.D.; Britten, J.A.

    1996-06-01

    The ability to produce short laser pulses of extremely high power and high irradiance, as is needed for fast ignitor research in inertial confinement fusion, places increasing demands on optical components such as amplifiers, lenses, and mirrors that must remain undamaged by the radiation. The higher refractive index in the center of an intense laser beam acts as a focusing lens. The resulting wavefront distortion, left uncorrected, eventually leads to catastrophic filamentation. Major advances in energy extraction and resulting increases in focused irradiance have been made possible by the use of chirped-pulse amplification (CPA), long used in radar applications and newly applied to optical frequencies. Optical-frequency CPA systems begin with a mode-locked oscillator that produces low-energy seed pulses with durations of ten to a few hundred femtoseconds. As a result of the classical uncertainty relation between time and frequency, these short pulses have a very broad frequency distribution. A pair of diffraction gratings (or other dispersive elements) lengthens the laser pulse and induces a time-varying frequency (or chirp). Following amplification, diffraction gratings compress the pulse back to nearly the original duration. Typically a nanojoule, femtosecond pulse is stretched by a factor of several thousand and is amplified by as much as 12 orders of magnitude before recompression. By producing the short pulse only after amplification, this technique makes possible efficient extraction of energy from a variety of broadband solid state materials. Achieving high focused irradiance from a pulse ultimately requires both high peak power and excellent beam quality. There is therefore a demand for diffraction gratings that produce a high-quality diffracted wavefront, have high diffraction efficiency, and exhibit a high threshold for laser damage.

  1. Antiproton catalyzed fusion

    SciTech Connect

    Morgan, D.L. Jr.; Perkins, L.J.; Haney, S.W.

    1995-05-15

    Because of the potential application to power production, it is important to investigate a wide range of possible means to achieve nuclear fusion, even those that may appear initially to be infeasible. In antiproton catalyzed fusion, the negative antiproton shields the repulsion between the positively charged nuclei of hydrogen isotopes, thus allowing a much higher level of penetration through the repulsive Coulomb barrier, and thereby greatly enhancing the fusion cross section. Because of their more compact wave function, the more massive antiprotons offer considerably more shielding than do negative muons. The effects of the shielding on fusion cross sections are most predominate, at low energies. If the antiproton could exist in the ground state with a nucleus for a sufficient time without annihilating, the fusion cross sections are so enhanced that at room temperature energies, values up to about 1,000 barns (that for d+t) would be possible. Unfortunately, the cross section for antiproton annihilation with the incoming nucleus is even higher. A model that provides an upper bound for the fusion to annihilation cross section for all relevant energies indicates that each antiproton will catalyze no more than about one fusion. Because the energy required to make one antiproton greatly exceeds the fusion energy that is released, this level of catalysis is far from adequate for power production.

  2. Charge Transfer and Triplet States in High Efficiency OPV Materials and Devices

    NASA Astrophysics Data System (ADS)

    Dyakonov, Vladimir

    2013-03-01

    The advantage of using polymers and molecules in electronic devices, such as light-emitting diodes (LED), field-effect transistors (FET) and, more recently, solar cells (SC) is justified by the unique combination of high device performance and processing of the semiconductors used. Power conversion efficiency of nanostructured polymer SC is in the range of 10% on lab scale, making them ready for up-scaling. Efficient charge carrier generation and recombination in SC are strongly related to dissociation of the primary singlet excitons. The dissociation (or charge transfer) process should be very efficient in photovoltaics. The mechanisms governing charge carrier generation, recombination and transport in SC based on the so-called bulk-heterojunctions, i.e. blends of two or more semiconductors with different electron affinities, appear to be very complex, as they imply the presence of the intermediate excited states, neutral and charged ones. Charge transfer states, or polaron pairs, are the intermediate states between free electrons/holes and strongly bound excitons. Interestingly, the mostly efficient OLEDs to date are based on the so-called triplet emitters, which utilize the triplet-triplet annihilation process. In SC, recent investigations indicated that on illumination of the device active layer, not only mobile charges but also triplet states were formed. With respect to triplets, it is unclear how these excited states are generated, via inter-system crossing or via back transfer of the electron from acceptor to donor. Triplet formation may be considered as charge carrier loss channel; however, the fusion of two triplets may lead to a formation of singlet excitons instead. In such case, a generation of charges by utilizing of the so far unused photons will be possible. The fundamental understanding of the processes involving the charge transfer and triplet states and their relation to nanoscale morphology and/or energetics of blends is essential for the

  3. High-efficiency, low-temperature cesium diodes with lanthanum-hexaboride electrodes

    NASA Technical Reports Server (NTRS)

    Morris, J. F.

    1974-01-01

    Lanthanum hexaboride electrodes in 1700 K cesium diodes may triple power outputs compared with those demonstrated for nuclear thermionic space applications. Still greater relative gains seem possible for emitters below 1700 K. Further improvements in cesium diode performance should result from the lower collector temperatures allowed for earth and low power space duties. Decreased temperatures will lessen thermal transport losses that attend thermionic conversion mechanisms. Such advantages will add to those from collector Carnot and electrode effects. If plasma ignition difficulties impede diode temperature reductions, recycling small fractions of the output power could provide ionization. So high efficiency, low temperature cesium diodes with lanthanum hexaboride electrodes appear feasible.

  4. 100 kW CW highly-efficient multi-beam klystron for a future electron-ion collider

    NASA Astrophysics Data System (ADS)

    Teryaev, Vladimir E.; Shchelkunov, Sergey V.; Jiang, Yong; Hirshfield, Jay L.

    2017-03-01

    Initial results are presented for the development of a CW highly-efficient RF source needed for operation of a future electron-ion collider. The design of this compact multi-beam klystron yields high efficiency (above 70%) for the power output of 125 kW at 952.6 MHz. The klystron is to work for the RF systems for ion acceleration in the polarized Medium-energy Electron Ion Collider as being developed at Thomas Jefferson National Accelerator Facility.

  5. Magnetized target fusion and fusion propulsion

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, Ronald C.

    2002-01-01

    Magnetized target fusion (MTF) is a thermonuclear fusion concept that is intermediate between the two mainline approaches, magnetic confinement and inertial confinement fusion (MCF and ICF). MTF incorporates some aspects of each and offers advantages over each of the mainline approaches. First, it provides a means of reducing the driver power requirements, thereby admitting a wider range of drivers than ICF. Second, the magnetic field is only used for insulation, not confinement, and the plasma is wall confined, so that plasma instabilities are traded in for hydrodynamic instabilities. However, the degree of compression required to reach fusion condition is lower than for ICF, so that hydrodynamic instabilities are much less threatening. The standoff driver innovation proposes to dynamically form the target plasma and a gaseous shell that compresses and confines the target plasma. Therefore, fusion target fabrication is traded in for a multiplicity of plasma guns, which must work in synchrony. The standoff driver embodiment of MTF leads to a fusion propulsion system concept that is potentially compact and lightweight. We will discuss the underlying physics of MTF and some of the details of the fusion propulsion concept using the standoff driver approach. We discuss here the optimization of an MTF target design for space propulsion. .

  6. Revitalizing Fusion via Fission Fusion

    NASA Astrophysics Data System (ADS)

    Manheimer, Wallace

    2001-10-01

    Existing tokamaks could generate significant nuclear fuel. TFTR, operating steady state with DT might generate enough fuel for a 300 MW nuclear reactor. The immediate goals of the magnetic fusion program would necessarily shift from a study of advanced plasma regimes in larger sized devices, to mostly known plasmas regimes, but at steady state or high duty cycle operation in DT plasmas. The science and engineering of breeding blankets would be equally important. Follow on projects could possibly produce nuclear fuel in large quantity at low price. Although today there is strong opposition to nuclear power in the United States, in a 21st century world of 10 billion people, all of whom will demand a middle class life style, nuclear energy will be important. Concern over greenhouse gases will also drive the world toward nuclear power. There are studies indicating that the world will need 10 TW of carbon free energy by 2050. It is difficult to see how this can be achieved without the breeding of nuclear fuel. By using the thorium cycle, proliferation risks are minimized. [1], [2]. 1 W. Manheimer, Fusion Technology, 36, 1, 1999, 2.W. Manheimer, Physics and Society, v 29, #3, p5, July, 2000

  7. Optimal design study of high efficiency indium phosphide space solar cells

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Flood, Dennis J.

    1990-01-01

    Recently indium phosphide solar cells have achieved beginning of life AMO efficiencies in excess of 19 pct. at 25 C. The high efficiency prospects along with superb radiation tolerance make indium phosphide a leading material for space power requirements. To achieve cost effectiveness, practical cell efficiencies have to be raised to near theoretical limits and thin film indium phosphide cells need to be developed. The optimal design study is described of high efficiency indium phosphide solar cells for space power applications using the PC-1D computer program. It is shown that cells with efficiencies over 22 pct. AMO at 25 C could be fabricated by achieving proper material and process parameters. It is observed that further improvements in cell material and process parameters could lead to experimental cell efficiencies near theoretical limits. The effect of various emitter and base parameters on cell performance was studied.

  8. Note: High-efficiency broadband acoustic energy harvesting using Helmholtz resonator and dual piezoelectric cantilever beams

    SciTech Connect

    Yang, Aichao; Li, Ping Wen, Yumei; Lu, Caijiang; Peng, Xiao; He, Wei; Zhang, Jitao; Wang, Decai; Yang, Feng

    2014-06-15

    A high-efficiency broadband acoustic energy harvester consisting of a compliant-top-plate Helmholtz resonator (HR) and dual piezoelectric cantilever beams is proposed. Due to the high mechanical quality factor of beams and the strong multimode coupling of HR cavity, top plate and beams, the high efficiency in a broad bandwidth is obtained. Experiment exhibits that the proposed harvester at 170–206 Hz has 28–188 times higher efficiency than the conventional harvester using a HR with a piezoelectric composite diaphragm. For input acoustic pressure of 2.0 Pa, the proposed harvester exhibits 0.137–1.43 mW output power corresponding to 0.035–0.36 μW cm{sup −3} volume power density at 170–206 Hz.

  9. Note: High-efficiency broadband acoustic energy harvesting using Helmholtz resonator and dual piezoelectric cantilever beams.

    PubMed

    Yang, Aichao; Li, Ping; Wen, Yumei; Lu, Caijiang; Peng, Xiao; He, Wei; Zhang, Jitao; Wang, Decai; Yang, Feng

    2014-06-01

    A high-efficiency broadband acoustic energy harvester consisting of a compliant-top-plate Helmholtz resonator (HR) and dual piezoelectric cantilever beams is proposed. Due to the high mechanical quality factor of beams and the strong multimode coupling of HR cavity, top plate and beams, the high efficiency in a broad bandwidth is obtained. Experiment exhibits that the proposed harvester at 170-206 Hz has 28-188 times higher efficiency than the conventional harvester using a HR with a piezoelectric composite diaphragm. For input acoustic pressure of 2.0 Pa, the proposed harvester exhibits 0.137-1.43 mW output power corresponding to 0.035-0.36 μW cm(-3) volume power density at 170-206 Hz.

  10. High Efficiency Adsorption Chillers: High Efficiency Adsorption Cooling Using Metal Organic Heat Carriers

    SciTech Connect

    2010-10-01

    BEETIT Project: PNNL is incorporating significant improvements in materials that adsorb liquids or gases to design more efficient adsorption chillers. An adsorption chiller is a type of air conditioner that is powered by heat, solar or waste heat, or combustion of natural gas. Unlike typical chillers, this type has few moving parts and uses almost no electricity to operate. PNNL is designing adsorbent materials at the molecular level with at least 3 times higher refrigerant capacity and up to 20 times faster kinetics than adsorbents used in current chillers. By using the new adsorbent, PNNL is able to create a chiller that is significantly smaller, has twice the energy efficiency, and lower costs for materials and assembly time compared to conventional adsorption chillers.

  11. The Path to Magnetic Fusion Energy

    SciTech Connect

    Prager, Stewart

    2011-05-04

    When the possibility of fusion as an energy source for electricity generation was realized in the 1950s, understanding of the plasma state was primitive. The fusion goal has been paced by, and has stimulated, the development of plasma physics. Our understanding of complex, nonlinear processes in plasmas is now mature. We can routinely produce and manipulate 100 million degree plasmas with remarkable finesse, and we can identify a path to commercial fusion power. The international experiment, ITER, will create a burning (self-sustained) plasma and produce 500 MW of thermal fusion power. This talk will summarize the progress in fusion research to date, and the remaining steps to fusion power.

  12. A strategy to design highly efficient porphyrin sensitizers for dye-sensitized solar cells.

    PubMed

    Chang, Yu-Cheng; Wang, Chin-Li; Pan, Tsung-Yu; Hong, Shang-Hao; Lan, Chi-Ming; Kuo, Hshin-Hui; Lo, Chen-Fu; Hsu, Hung-Yu; Lin, Ching-Yao; Diau, Eric Wei-Guang

    2011-08-21

    We designed highly efficient porphyrin sensitizers with two phenyl groups at meso-positions of the macrocycle bearing two ortho-substituted long alkoxyl chains for dye-sensitized solar cells; the ortho-substituted devices exhibit significantly enhanced photovoltaic performances with the best porphyrin, LD14, showing J(SC) = 19.167 mA cm(-2), V(OC) = 0.736 V, FF = 0.711, and overall power conversion efficiency η = 10.17%.

  13. High-efficiency backlight module with two guiding modes.

    PubMed

    Li, Chang-Yi; Pan, Jui-Wen

    2014-03-10

    We propose a design for a high-efficiency backlight module that does not require a brightness enhancement film (BEF). With the high-efficiency backlight module it is possible to achieve almost the same half-luminance angle as a conventional edge-lit backlight module can achieve. The backlight system is comprised of a crisscross light guide plate (LGP) and one diffuser sheet. The crisscross LGP is composed of a LGP and optically patterned film (OPF). The backlight module allows light to be extracted through the direct guiding mode and top guiding mode, respectively. We controlled arrangement of the microstructures to increase the optical efficiency and the uniformity by two modes. Compared to the conventional edge-lit backlight module, there is a two-fold improvement in both the total optical efficiency and on-axis luminance with the high-efficiency backlight module.

  14. ITER Fusion Energy

    ScienceCinema

    Dr. Norbert Holtkamp

    2016-07-12

    ITER (in Latin “the way”) is designed to demonstrate the scientific and technological feasibility of fusion energy. Fusion is the process by which two light atomic nuclei combine to form a heavier over one and thus release energy. In the fusion process two isotopes of hydrogen – deuterium and tritium – fuse together to form a helium atom and a neutron. Thus fusion could provide large scale energy production without greenhouse effects; essentially limitless fuel would be available all over the world. The principal goals of ITER are to generate 500 megawatts of fusion power for periods of 300 to 500 seconds with a fusion power multiplication factor, Q, of at least 10. Q ? 10 (input power 50 MW / output power 500 MW). The ITER Organization was officially established in Cadarache, France, on 24 October 2007. The seven members engaged in the project – China, the European Union, India, Japan, Korea, Russia and the United States – represent more than half the world’s population. The costs for ITER are shared by the seven members. The cost for the construction will be approximately 5.5 billion Euros, a similar amount is foreseen for the twenty-year phase of operation and the subsequent decommissioning.

  15. Present status of liquid metal research for a fusion reactor

    NASA Astrophysics Data System (ADS)

    Tabarés, Francisco L.

    2016-01-01

    Although the use of solid materials as targets of divertor plasmas in magnetic fusion research is accepted as the standard solution for the very challenging issue of power and particle handling in a fusion reactor, a generalized feeling that the present options chosen for ITER will not represent the best choice for a reactor is growing up. The problems found for tungsten, the present selection for the divertor target of ITER, in laboratory tests and in hot plasma fusion devices suggest so. Even in the absence of the strong neutron irradiation expected in a reactor, issues like surface melting, droplet ejection, surface cracking, dust generation, etc., call for alternative solutions in a long pulse, high efficient fusion energy-producing continuous machine. Fortunately enough, decades of research on plasma facing materials based on liquid metals (LMs) have produced a wealth of appealing ideas that could find practical application in the route to the realization of a commercial fusion power plant. The options presently available, although in a different degree of maturity, range from full coverage of the inner wall of the device with liquid metals, so that power and particle exhaust together with neutron shielding could be provided, to more conservative combinations of liquid metal films and conventional solid targets basically representing a sort of high performance, evaporative coating for the alleviation of the surface degradation issues found so far. In this work, an updated review of worldwide activities on LM research is presented, together with some open issues still remaining and some proposals based on simple physical considerations leading to the optimization of the most conservative alternatives.

  16. A Plan for the Development of Fusion Energy. Final Report to Fusion Energy Sciences Advisory Committee, Fusion Development Path Panel

    SciTech Connect

    None, None

    2003-03-05

    This report presents a plan for the deployment of a fusion demonstration power plant within 35 years, leading to commercial application of fusion energy by mid-century. The plan is derived from the necessary features of a demonstration fusion power plant and from the time scale defined by President Bush. It identifies critical milestones, key decision points, needed major facilities and required budgets.

  17. Accelerators for heavy ion fusion

    SciTech Connect

    Bangerter, R.O.

    1985-10-01

    Large fusion devices will almost certainly produce net energy. However, a successful commercial fusion energy system must also satisfy important engineering and economic constraints. Inertial confinement fusion power plants driven by multi-stage, heavy-ion accelerators appear capable of meeting these constraints. The reasons behind this promising outlook for heavy-ion fusion are given in this report. This report is based on the transcript of a talk presented at the Symposium on Lasers and Particle Beams for Fusion and Strategic Defense at the University of Rochester on April 17-19, 1985.

  18. A review of high-efficiency silicon solar cells

    NASA Technical Reports Server (NTRS)

    Rohatgi, A.

    1986-01-01

    Various parameters that affect solar cell efficiency were discussed. It is not understood why solar cells produced from less expensive Czochralski (Cz) silicon are less efficient than cells fabricated from more expensive float-zone (Fz) silicon. Performance characteristics were presented for recently produced, high-efficient solar cells fabricated by Westinghouse Electric Corp., Spire Corp., University of New South Wales, and Stanford University.

  19. Development of an Improved High Efficiency Thin Solar Cell

    NASA Technical Reports Server (NTRS)

    Lindmayer, J.; Wrigley, C.; Storti, G.

    1979-01-01

    High efficiency cells (up to 14 AMO at 25 C)were fabricated from 10 - 15 ohm-cm silicon by using screen printed aluminum paste as the alloy source for the production of back surface fields. Thick consistency pastes that have been cured prior to a short heat treatment at 850 C were most effective in achieving these efficiency levels.

  20. Development of High Efficiency (14%) Solar Cell Array Module

    NASA Technical Reports Server (NTRS)

    Iles, P. A.; Khemthong, S.; Olah, S.; Sampson, W. J.; Ling, K. S.

    1979-01-01

    High efficiency solar cells required for the low cost modules was developed. The production tooling for the manufacture of the cells and modules was designed. The tooling consisted of: (1) back contact soldering machine; (2) vacuum pickup; (3) antireflective coating tooling; and (4) test fixture.