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Manufacturing monitoring and mock-ups validation of the WEST divertor structure and coils

FUSION engineering AND design 2015年 98-99卷 1474-1478页

作者： Doceul, Louis Bucalossi, Jerome Decool, Patrick Dougnac, Hubert Ferlay, Fabien Gargiulo, Laurent Keller, Delphine Larroque, Sebastien Lipa, Manfred Martino, Patrick Pilia, Arnaud Poli, Serge Portafaix, Christophe Saille, Alain Salami, Michael Samaille, Frank Soler, Bernard Thouvenin, Didier verger, Jean-Marc voyard, Olivier Zago, Bertrand CEA IRFM F-13108 St Paul Les Durance France ITER Org F-13115 St Paul Les Durance France AVANTIS Engn Grp F-46100 Zi De Laiguille Figeac France CNIM F-83500 Zi De Bregaillon La Seyne Sur Me France

In order to fully validate "ITER-like" actively water cooled tungsten plasma facing units, the implementation of an axisymmetric divertor structure in the Tokamak Tore-Supra has been studied. With this major upgrade, the so-called WEST (Tungsten Environment in Steady state Tokamak), Tore-Supra will be able to address the issues of long plasma discharges using a tungsten divertor based on monoblock targets. The divertor structure and coils assembly are made up of two stainless steel casings containing a copper winding pack cooled by a pressurized hot water circuit (up to 180 degrees C, 4 MPa) in which a total divertor current of up to 16 x 13 kA is circulating in steady state. The conductor is electrically insulated and wedged inside the casing in order to be mechanically protected. The divertor which is designed to perform steady state plasma operation (up to 1000 s), must sustain harsh environmental conditions in terms of ultra light vacuum conditions, electromagnetical loads and electrical insulation (5 kv ground voltage) under high temperature (180 degrees C). Therefore, a feasibility study of such a complex structure has been performed. It implied activities on a scale one dummy coil, such as installation, assembly issues and representative tests (electric, thermal and hydraulic). The manufacturing of the divertor structure, which is a large assembly of 4-m diameter representing a total weight of around 20 tonnes, started in the second half of 2013 and is expected to be delivered by the end of 2014. The paper will illustrate the technical developments and tests performed during 2013 and beginning of 2014 in order to fully validate the design concept before the industrial phase. The manufacturing methods proposed by the contractor in order to fulfil the technical requirements will be also addressed. (C) 2015 Elsevier B.v. All rights reserved.

关键词： Tore-Supra Divertor engineering Coil WEST

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The Efficiency of Uv LEDs Based on GaN/AlGaN Heterostructures

The Efficiency of UV LEDs Based on GaN/AlGaN Heterostructure...

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IEEE North West Russia Section Young Researchers in Electrical and Electronic engineering Conference (2015 ElConRusNW)

作者： Eyseenkov, A. S. Tarasov, S. A. Lamkin, I. A. Solomonov, A. v. Kurin, S. Yu. St Petersburg Electrotech Univ LETI St Petersburg Russia Nitride Crystals Ltd St Petersburg 194156 Russia

ISBN: (纸本)9781479973064

The Uv LED heterostructures have been obtained by HvPE approach and investigated by XRD, AFM and PL methods. The experiment shows that the peak wavelength of Uv LEDs is in the range of 360-365 nm with FWHM of 10-13 nm. At operating current of 20 mA the active region temperature Tj is 43 degrees C, the output optical power and efficiency - 1.14 mW and 1.46 %, respectively. It is presented a model based on corpuscular Monte Carlo method in order to calculate the light extraction index. The simulation results allow us to propose the ways to increase the efficiency of Uv LEDs by 3-4 times: surface interfaces texturing, optimization of the design of heterostructures, and the use of lenses.

关键词： Uv LEDs efficiency Monte-Carlo method

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developments in Strategic Materials and Computational design v 1

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丛书名： Ceramic engineering and Science Proceedings

2015年

作者： Kriven Waltraud M. Zhu Dongming Moon Kyoung Il Hwang Taejin Wang Jingyang Lewinsohn Charles A. Zhou Yanchun Gyekenyesi Andrew L. Halbig Michael

ISBN: (数字)9781119040316

ISBN: (纸本)9781119040286

This issue contains 31 papers from The American Ceramic Society’s 38th International Conference on Advanced Ceramics and Composites, held in Daytona Beach, Florida, January 26-31, 2014. This issue includes papers presented in the following Symposia and Focused Sessions: Symposium 2 – Advanced Ceramic Coatings for Structural, Environmental, and Functional Applications; Symposium 10 – virtual Materials (Computational) design and Ceramic Genome; Symposium 11 – Advanced Materials and Innovative Processing Ideas for the Industrial Root Technology; Symposium 12 – Materials for Extreme Environments: Ultrahigh Temperature Ceramics and Nanolaminated Ternary Carbides and Nitrides; Focused Session 1 - Geopolymers and Chemically Bonded Ceramics; Focused Session 2 – Advanced Ceramic Materials and Processing for Photonics and Energy; Focused Session 3 – Rare Earth Oxides for Energy, optical and Biomedical Applications, Focused Session 4 – Ion-Transport Membranes; 3rd Global Pacific Rim engineering Ceramics Summit; and the 3rd Annual Global Young Investigator Forum

关键词： nabh ceramics schomborg introduction composites geopolymers ix geopolymer lars situ carbothermal reduction kiesel powder carbonnano nitridation bagci cengieffect kriven ratio solutions geomaterial

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Impact of photon recycling and luminescence coupling in III-v photovoltaic devices 4

Impact of photon recycling and luminescence coupling in III-...

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Physics, Simulation, and Photonic engineering of Photovoltaic Devices Iv

作者： Walker, A.W. Höhn, O. Micha, D.N. Wagner, L. Helmers, H. Bett, A.W. Dimroth, F. Fraunhofer Institute for Solar Energy Systems ISE Heidenhofstraße 2 Freiburg79110 Germany

ISBN: (纸本)9781628414486

Single junction photovoltaic devices composed of direct bandgap III-v semiconductors such as GaAs can exploit the effects of photon recycling to achieve record-high open circuit voltages. Modeling such devices yields insight into the design and material criteria required to achieve high efficiencies. For a GaAs cell to reach 28 % efficiency without a substrate, the Shockley-Read-Hall (SRH) lifetimes of the electrons and holes must be longer than 3 μs and 100 ns respectively in a 2 μm thin active region coupled to a very high reflective (>99%) rear-side mirror. The model is generalized to account for luminescence coupling in tandem devices, which yields direct insight into the top cell's non-radiative lifetimes. A heavily current mismatched GaAs/GaAs tandem device is simulated and measured experimentally as a function of concentration between 3 and 100 suns. The luminescence coupling increases from 14 % to 33 % experimentally, whereas the model requires an increasing SRH lifetime for both electrons and holes to explain these experimental results. However, intermediate absorbing GaAs layers between the two sub-cells may also increasingly contribute to the luminescence coupling as a function of concentration. © 2015 SPIE.

关键词： Luminescence

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Direct band gap In_xGa_1-xAs/Ge type II strained quantum wells for short-wave infrared p-i-n photodetector

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optical MATERIALS 2015年 46卷 472-480页

作者： Harbi, N. Sfina, N. Jbeli, A. Lazzari, J-L Said, M. Fac Sci Monastir Dept Phys LMCN Monastir 5019 Tunisia Aix Marseille Univ UMR CNRS 7325 Ctr Interdisciplinaire Nanosci Marseille CINaM F-13288 Marseille 9 France King Khalid Univ Fac Sci & Art Mahail Assir Saudi Arabia Majmaah Univ Coll Sci & Humanities Ghat Ghat 11914 Saudi Arabia

We theoretically investigate GaAs/Ge/InGaAs as a quantum wells for the design of short-wave infrared p-i-n photodetectors in which the quantum well Ge/InGaAs is the active region. At room temperature, strained Ge/InxGa1-xAs becomes a direct band gap when In composition x is lower than 2.5% and 5% respectively. We have calculated the electronic band parameiers for the heterointerface Ge/InxGa1-xAs. Then, a type-II strain GaAs/Ge/In0.35Ga0.65As/GaAs quantum wells heterostructure optimized in terms of compositions and thicknesses is studied by solving Schrodinger equation as well as the absorption coefficient (>1.5 x 10(4) cm(-1)). These computations have been used for the study of p-i-n infrared photodetectors operating at room temperature in the range 13-1.55 mu m. The electron transport in the GaAs/Ge/In0.35Ga0.65As/GaAs multi-quantum wells-based p-i-n structure was analyzed and numerically simulated taking into account tunneling process and thermally activated transfer through the barriers mainly. The temperature dependence of dark current mechanisms and zero-bias resistance area product (R(0)A) have been analyzed. Extracted from current-voltage characteristics, R(0)A products above 3.6.10(6) Omega cm(2) at 77 K were calculated, and the quantitative analysis of the J-v curves showed that the dark current density of Ge/In0.35Ga0.65As photodetector is dominated by generation-recombination processes. The suitability of the modeled photodetector is approved by its feasibility of achieving good device performance near room temperature operating at 1.55 mu m. Quantum efficiency of similar to 90% and responsivity similar to 0.6 A/W, have been achieved. (C) 2015 Elsevier B.v. All rights reserved.

关键词： Band engineering Absorption Strained Ge/InxGa1-xAs Infrared photodetector Dark current

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应用二维轴对称场有限元法的电站型MOA电位分布计算及均压设计

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电瓷避雷器 2016年第2期 155-161页

作者：陈忠黄贵均广东水利电力职业技术学院电力工程系

由于电站型氧化锌避雷器的上端电阻片承受电压过高,并随着避雷器安装高度减小而更为严重,导致上端电阻片电压承担率过大而易造成整台避雷器的损坏,因此计算并优化避雷器的电位分布具有重要的工程意义。本文将电站型,氧化锌避雷器的电位... 详细信息

由于电站型氧化锌避雷器的上端电阻片承受电压过高,并随着避雷器安装高度减小而更为严重,导致上端电阻片电压承担率过大而易造成整台避雷器的损坏,因此计算并优化避雷器的电位分布具有重要的工程意义。本文将电站型,氧化锌避雷器的电位计算问题等效为分层均匀媒质的多介质闭域静电场问题,采用轴对称处理方法,建立二维轴对称场有限元模型,计算具有开域边界的电站型氧化锌避雷器的电位分布。以220 k v电站型,氧化锌避雷器为例,研究了底座高度、均压环位置等因素对整组电阻片电位分布的影响,并采用光纤电流法对均压后的避雷器电位分布进行实验测量。得出:底座高度超过2 m时,其对电压承担率几乎没有影响;优化高压端均压环的直径及套入深度可使避雷器的整体电位分布达到最优,得到较为合理的避雷器均压设计方案。

关键词：氧化锌避雷器有限元法二维轴对称封闭域光纤电流法电位分布均压设计

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design and Implementation of a High-Performance Readout Circuit for Uncooled Infrared Detector

Design and Implementation of a High-Performance Readout Circ...

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Annual Conference of the Chinese-Society-for-optical-engineering on Applied Optics and Photonics, China (AOPC)

作者： Yuan, Honghui Chen, Shijun Zhai, Houming Chen, Yongping Chinese Acad Sci Shanghai Inst Tech Phys Key Lab Infrared Imaging Mat & Detectors Shanghai 200083 Peoples R China

ISBN: (纸本)9781628418996

At present, most uncooled infrared detectors circuits consist of the corresponding blind pixel detector, which increases the complexity of uncooled infrared detector, and the performance of the readout circuits is not ideal in practical applications. In order to achieve high performance of the readout circuit for uncooled infrared detectors, a kind of readout circuit based on current mirror has been designed in this paper. The readout circuit is composed of current mirror input part, capacitor feedback transimpedance amplifier (CTIA) and correlated double sampling (CDS) output circuit. Transconductance amplifier CTIA with capacitance negative feedback is used in the circuit and it consists of three integral capacitors, thus the circuit can realize different magnifications. The CDS N SF (source follow) and P SF are adopted as the circuit's output, the output swing can easily be greater than 2v. In average, the CDS N SF and P SF's power consumption is very low. So the total power consumption of 160 line circuit is about 100 mW. The non-uniformity of circuit has been obviously improved by reasonable parameter settings. In the test, the non-uniformity of the readout circuit has reached 1%. The other test results of total power consumption and the output amplitude also agree with simulation results. When the readout circuit and uncooled infrared detector are connected, the infrared signal can be well read out. the device has good noise characteristics and the NETD(noise equivalent temperature difference) is near 80mK. When the integration time is 20 mu s, the whole device's response is about 15mv/K.

关键词： High-performance current mirror Uncooled IR detector CMOS readout circuit

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A new design of filter system in streak camera

A new design of filter system in streak camera

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Annual Conference of the Chinese-Society-for-optical-engineering on Applied Optics and Photonics, China (AOPC)

作者： Zhou, Pengyu Bai, Yonglin Chinese Acad Sci Xian Inst Opt & Precis Mech Xian Peoples R China Univ Chinese Acad Sci Beijing Peoples R China

ISBN: (纸本)9781628419023

In order to reduce the frequency of researchers routing in and out of the testing site and ensure the fluency of the testing we design a new filter system applied to the streak cameras. This system promotes streak cameras' abilities on spatial discrimination and time resolution. This paper focuses on the instruction of the piezoelectric motor's principle based on field-effect tubes. Filter wheel is driven by piezoelectric motor. It can effectively avoid the influences of high field produced by streak tube. Finally we achieve auto regulation at different gears and promote the efficiency of operations and guarantee the safety of researchers. CD4046 introduces the driven clock of this system and we use an inverter to get two synchronous inverted signals. These signals are amplified by field-effect tubes to more than 300v. The amplified ones are integrated at the output terminals to generate sinusoidal signal. The test shows that in this filter system piezoelectric motor operates at its resonance frequency under a control signal of 62.5 KHz. Its working current is 1.9A and driving power is almost 10W. By adjusting the gears, the filter wheel costs less than 2 seconds to calibrate. We accomplish the test in respected results.

关键词： Streak Camera no magnetic motor automatic filter

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Ultimate modulation bandwidth of 850 nm oxide-confined vertical-cavity surface-emitting lasers 2

Ultimate modulation bandwidth of 850 nm oxide-confined verti...

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2nd International School and Conference Saint-Petersburg OPEN on Optoelectronics, Photonics, engineering and Nanostructures (SPbOPEN2015)

作者： Bobrov, M. A. Blokhin, S. A. Maleev, N. A. Kuzmenkov, A. G. Blokhin, A. A. Zadiranov, Yu M. Troshkov, S. I. Ledentsov, N. N. Ustinov, v. M. Ioffe Inst St Petersburg 194021 Russia Peter Great St Petersburg Polytech Univ St Petersburg 195251 Russia VI Syst GmbH D-10623 Berlin Germany

Complex influence of photon lifetime (controlled by the mirror loss) and aperture size on the performance of 850 nm InGaAlAs oxide-confined vertical-cavity surface-emitting lasers (vCSELs) with fully doped AlGaAs-based distributed Bragg reflectors (DBR) was investigated. We find a tradeoff between photon lifetime and gain nonlinearity for maximizing the optical bandwidth, leading to the optimum aperture size close to 4-6 mu m. In spite of the reduced photon lifetime (from 4 ps to 1 ps), the excess damping caused by the current-induced self-heating limits the ultimate modulation bandwidth for the given vCSELs design at 2425 GHz. Further improvement in high frequency characteristics can be facilitated by decrease of the heat generation and improvement of the heat removal from the active region as well as by proper engineering of the scattering loss at the oxide aperture while keeping the low capacitance optimizing design of the oxide aperture.

关键词： Surface emitting lasers

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Novel waveguide reactor design for enhancing algal biofilm growth

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ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS 2015年 12卷 529-538页

作者： Genin, Scott N. Aitchison, J. Stewart Allen, D. Grant Univ Toronto Dept Chem Engn & Appl Chem 200 Coll St Toronto ON M5S 3E5 Canada Univ Toronto Edward S Rogers Sr Dept Elect & Comp Engn Toronto ON M5S 3G4 Canada

Algal film photobioreactors have the potential to reduce dewatering costs and have a comparable productivity to raceway ponds. current designs have focused on maximizing productivity and nutrient removal through material selection and design. However, fewer studies have focused on analyzing the effects of illumination and carbon dioxide (CO2) concentration on algal film growth. The transport of light in suspended photobioreactors is considered a serious problem due to cell shading, light scattering and non-uniform optical absorption. To enhance light delivery to algal biofilms, five different waveguide designs were developed Light emitting waveguides are capable of distributing a bright light source over a larger surface area. The light emission from these waveguide designs was characterized and the algal biofilm growth on waveguides was characterized in a parallel plate airlift reactor (17 L). The light intensity and CO2 concentration were varied in a 32 factorial design experiment to determine if there were any interaction effects. Light emission from the waveguides could be altered by changing the tapper angle or by notching the surfaces. Algal film growth kinetics on the waveguides were overall non-linear, but had linear regions of growth. The waveguides achieved an algal biofilm surface area productivity of 2.8 g/m(2) day and an aerial productivity of 33.6 g/m(2) day. Algal film productivity displayed saturation kinetics with respect to light intensity and CO2 concentration, but the interaction effect of light and CO2 on productivity is likely non-linear. Algal film biomass per photon consumed decreased with increasing light intensity when the reactor was not CO2 limited. The results indicate the potential for algal biofilms to be grown on light emitting waveguides which opens up the opportunity to explore new algal film photobioreactor configurations. (C) 2015 Elsevier B.v. All rights reserved.

关键词： Algae biofilm Algae production Light waveguide Photobioreactor

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