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Conference on High Energy, optical, and Infrared Detectors for Astronomy vII

作者： Salter, Mike Clapp, Matthew King, James Morse, Tom Mihalcea, Ionut Waltham, Nick Hayes-Thakore, Chris Rutherford Appleton Lab STFC RAL Space Didcot OX11 0QX Oxon England E2v Technol 106 Waterhouse Lane Chelmsford CM1 2QU Essex England

ISBN: (纸本)9781510602090;9781510602106

World Space Observatory Ultraviolet (WSO-Uv) is a major Russian-led international collaboration to develop a large space-borne 1.7 m Ritchey-Chretien telescope and instrumentation to study the universe at ultraviolet wavelengths between 115 nm and 320 nm, exceeding the current capabilities of ground-based instruments. The WSO Ultraviolet Spectrograph subsystem (WUvS) is led by the Institute of Astronomy of the Russian Academy of Sciences and consists of two high resolution spectrographs covering the Far-Uv range of 115-176 nm and the Near-Uv range of 174-310 nm, and a long-slit spectrograph covering the wavelength range of 115-305 nm. The custom-designed CCD sensors and cryostat assemblies are being provided by e2v technologies (UK). STFC RAL Space is providing the Camera Electronics Boxes (CEBs) which house the CCD drive electronics for each of the three WUvS channels. This paper presents the results of the detailed characterisation of the WUvS CCD drive electronics. The electronics include a novel high-performance video channel design that utilises Digital Correlated Double Sampling (DCDS) to enable low-noise readout of the CCD at a range of pixel frequencies, including a baseline requirement of less than 3 electrons rms readout noise for the combined CCD and electronics system at a readout rate of 50 kpixels/s. These results illustrate the performance of this new video architecture as part of a wider electronics sub-system that is designed for use in the space environment. In addition to the DCDS video channels, the CEB provides all the bias voltages and clocking waveforms required to operate the CCD and the system is fully programmable via a primary and redundant SpaceWire interface. The development of the CEB electronics design has undergone critical design review and the results presented were obtained using the engineering-grade electronics box. A variety of parameters and tests are included ranging from general system metrics, such as the power and mass, to

关键词： DCDS correlated double sampling CCD readout CCD drive electronics World Space Observatory ultraviolet spectrograph WSO WUvS

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design, developments, and results from the NIST additive manufacturing metrology testbed (AMMT) 27

Design, developments, and results from the NIST additive man...

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27th Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference, SFF 2016

作者： Lane, B. Mekhontsev, S. Grantham, S. vlasea, M.L. Whiting, J. Yeung, H. Fox, J. Zarobila, C. Neira, J. McGlauflin, M. Hanssen, L. Moylan, S. Donmez, A. Rice, J. Engineering Laboratory National Institute of Standards and Technology GaithersburgMD20899 United States Physical Measurement Laboratory National Institute of Standards and Technology GaithersburgMD20899 United States Mechanical and Mechatronics Engineering University of Waterloo WaterlooONN2L 3GI Canada

The National Institute of Standards and Technology (NIST) is developing a facility titled the Additive Manufacturing Metrology Testbed that will enable advanced research into monitoring, controls, process development, and temperature measurement for laser powder bed fusion additive manufacturing and similar processes. This system provides an open control architecture as well as a plethora of sensor systems and calibration sources that are primarily radiance-based and aligned co-axially with the laser beam and focused on the laser interaction zone. This paper briefly reviews the system requirements, and details the current progress of the facility design and construction. Mechanical, optical, and control systems designs are detailed with select highlights that may be relevant to additive manufacturing researchers and system developers. Recent experimental results from the prototype laser control and in-situ monitoring system are also highlighted. © 2016 The Department of Energy’s Kansas City National Security Campus is operated and managed by Honeywell Federal Manufacturing Technologies, LLC under contract number DE-NA0002839.

关键词： 3D printers

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A Tunnel FET design for High-current, 120 mv Operation 62

A Tunnel FET Design for High-Current, 120 mV Operation

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62nd Annual IEEE International Electron Devices Meeting (IEDM)

作者： Long, P. Huang, J. Z. Povolotskyi, M. verreck, D. Charles, J. Kubis, T. Klimeck, G. Rodwell, M. J. W. Calhoun, B. H. Purdue Univ Network Computat Nanotechnol W Lafayette IN 47906 USA Katholieke Univ Leuven Dept Elect Engn IMEC B-3001 Leuven Belgium Univ Calif Santa Barbara ECE Dept Santa Barbara CA 93106 USA Univ Virginia ECE Dept Charlottesville VA 22904 USA

ISBN: (纸本)9781509039029

We report simulations of logic transistor operation at supply voltages v-DD between 0.08-0.18v. Tunnel FETs (TFETs) can operate at low voltage with low off-currents I-OFF, but on-currents I-ON are greatly reduced by low tunneling probability. The minimum feasible vDD is constrained not only by the transistor subthreshold swing (SS) given a target I-ON/I-OFF ratio, but also by the reduction of the drain current as the drain Fermi level approaches the channel conduction-band energy. This output conductance reduces the TFET voltage gain and impairs the logic gate noise margin;increasing the TFET threshold voltage v-th increases the noise margin while reducing both I-ON and I-OFF. In ballistic simulations with 10(-3)A/m I-OFF, triple-heterojunction tunnel FETs (3HJ-TFET5) show >50% tunneling probability and a high 265A/m ION at v-DD= 0.18v and 195A/m at v-DD=0.12v. In simulations with an optical deformation constant (proportional to scattering strength) of 220mev/nm, consistent with mu=1.1x10(5) cm(2)v(-1)s(-1), reduces /I-ON by 31% given fixed I-OFF and v-DD. In ballistic simulations, increasing v-th by 0.02v above that required for 10-3A/m I-OFF, a noise margin of 24% of v-DD is obtained at v-DD=0.12v.

关键词： Ions

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Performance and future developments of the RHEA single-mode spectrograph 6

Performance and future developments of the RHEA single-mode ...

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Conference on Ground-Based and Airborne Instrumentation for Astronomy vI

作者： Bento, Joao Feger, Tobias Ireland, Michael J. Rains, Adam Jovanovic, Nemanja Coutts, David W. Schwab, Christian Arriola, Alexander Gross, Simon Australian Natl Univ Res Sch Astron & Astrophys Cotter Rd Canberra ACT 2611 Australia Macquarie Univ Dept Phys & Astron Sydney NSW 2109 Australia Natl Astron Observ Japan Subaru Telescope 650 North Aohoku Pl Hilo HI 96720 USA

ISBN: (数字)9781510601963

ISBN: (纸本)9781510601963

The Replicable High-resolution Exoplanet and Asteroseismology (RHEA) spectrograph is being developed to serve as a basis for multiple copies across a network of small robotic telescopes. The spectrograph operates at the diffraction-limit by using a single-mode fiber input, resulting in a compact and modal-noise-free unit. The optical design is mainly based on off-the-shelf available components and comprises a near-Littrow configuration with prism cross-disperser. The Echelle format covers a wavelength range of 430-650 nm at R=75,000 resolving power. In this paper we briefly summarize the current status of the instrument and present preliminary results from the first on-sky demonstration of the prototype using a fully automated 16" telescope, where we observe stable and semi-variable stars up to v=3.5 magnitude. Future steps to enhance the efficiency and passive stability of RHEA are discussed in detail. For example, we show the concept of using a multi-fiber injection unit, akin to a photonic lantern, which not only enables increased throughput but also offers simultaneous wavelength calibration.

关键词： High-resolution single-mode spectrograph integral field unit radial velocity exoplanets

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Coordinate interferometric measurement with infrared telecom laser diode 16

Coordinate interferometric measurement with infrared telecom...

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16th International Conference of the European Society for Precision engineering and Nanotechnology, EUSPEN 2016

作者： Lazar, Josef Holä, Miroslava Čížek, Martin Hucl, václav Rerucha, Šimon Číp, Ondrej Kralovopolska 147 Brno61264 Czech Republic

ISBN: (纸本)9780956679086

We present the design of an interferometric position measuring system for the control of the sample-carrying translation stage in an e-beam writer with reproducibility of the position on nanometre level and resolution below nanometre. We introduced differential configuration of the interferometer where the position is measured with respect to a central reference point to eliminate deformations caused by thermal and pressure effects on the vacuum chamber. The reference is here the electron gun of the writer. The interferometer is designed to operate at infrared telecommunication wavelength due to the risk of interference of stray light with sensitive photodetectors in the chamber. The laser source used is a narrow-linewidth DFB laser diode with a custom-developed electronics that allows for high precision and stability of the laser diode chip temperature and the injection current, very low-noise, EMI protection and high-frequency modulation capability. Detection of the interferometric signal relies on a technique using a high frequency modulation of the laser's optical frequency and the single-detector phase-sensitive detection.

关键词： Interferometry

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Assessing the progress of trapped-ion processors towards fault-tolerant quantum computation

arXiv

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arXiv 2017年

作者： Bermudez, A. Xu, X. Nigmatullin, R. Gorman, J.O. Negnevitsky, v. Schindler, P. Monz, T. Poschinger, U.G. Hempel, C. Home, J. Schmidt-Kaler, F. Biercuk, M. Blatt, R. Benjamin, S. Müller, M. Department of Physics College of Science Swansea University Singleton Park SwanseaSA2 8PP United Kingdom Instituto de Física Fundamental IFF-CSIC MadridE-28006 Spain Department of Materials University of Oxford OxfordOX1 3PH United Kingdom Complex Systems Research Group Faculty of Engineering and IT University of Sydney Sydney Australia Institute for Quantum Electronics ETH Zürich Otto-Stern-Weg 1 Zürich8093 Switzerland Institute for Experimental Physics University of Innsbruck Innsbruck6020 Austria Institut für Physik Universität Mainz Staudingerweg 7 Mainz55128 Germany ARC Centre for Engineered Quantum Systems School of Physics University of Sydney NSW2006 Australia Institute for Quantum Optics and Quantum Information Austrian Academy of Sciences InnsbruckA-6020 Austria

A quantitative assessment of the progress of small prototype quantum processors towards fault-tolerant quantum computation is a problem of current interest in experimental and theoretical quantum information science. We introduce a necessary and fair criterion for quantum error correction (QEC), which must be achieved in the development of these quantum processors before their sizes are sufficiently big to consider the well-known QEC threshold. We apply this criterion to benchmark the ongoing effort in implementing QEC with topological color codes using trapped-ion quantum processors and, more importantly, to guide the future hardware developments that shall be required in order to demonstrate beneficial QEC with small topological quantum codes. In doing so, we present a thorough description of a realistic trapped-ion toolbox for QEC, and a physically-motivated error model that goes beyond standard simplifications in the QEC literature. We focus on laser-based quantum gates realised in two-species trapped-ion crystals in high-optical aperture segmented traps. Our large-scale numerical analysis shows that, with the foreseen technological improvements hereby described, this platform is a very promising candidate for fault-tolerant quantum computation. Copyright © 2017, The Authors. All rights reserved.

关键词： Trapped ions

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Proceedings of SPIE - The International Society for optical engineering

Proceedings of SPIE - The International Society for Optical ...

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vertical External Cavity Surface Emitting Lasers (vECSELs) vI

ISBN: (纸本)9781628419696

The proceedings contain 31 papers. The topics discussed include: generation of new spatial and temporal coherent light states using III-v semiconductor laser technology: vORTEX, continuum, dual frequency for THz;terahertz quantum cascade vECSEL;broadly tunable DBR-free semiconductor disk lasers;resonant measurements of nonlinear lensing in a vECSEL gain sample;ultrafast characterization of semiconductor gain and absorber devices for mode-locked vECSELs;reection z-scan measurements of the non-linear lens in vECSEL gain structures;self-mode-locked vertical-external-cavity surface-emitting laser;a 1.5-W frequency-doubled semiconductor disk laser tunable over 40 nm at around 745 nm;advances in optically pumped semiconductor lasers for blue emission under frequency doubling;over 10 watt, collinear blue and green vertical external cavity surface emitting laser;gain chip design, power scaling and intra cavity frequency doubling with LBO of optically pumped red-emitting AlGaInP-vECSELs;influence of kinetic hole filling on the stability of mode-locked semiconductor disk lasers;advances in commercial, mode-locked vertical external cavity surface emitting lasers;and vertical external cavity surface emitting lasers for sodium guidestar applications and improvement of current guidestar systems.

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Progress towards quieter civil helicopters

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The Aeronautical Journal 2016年第956期96卷 209-223页

作者： M.v. Lowson Department of Aerospace Engineering University of Bristol

A review of recent developments in helicopter noise reduction is presented. The paper includes a discussion of the present state of understanding of helicopter noise radiation mechanisms and a review of actual noise reductions achieved by the manufacturers over the past decade. An analysis of progress achieved in meeting certification limits is given, together with an evaluation of the impact on design. Future trends in helicopter noise reduction based on current noise research programmes are discussed and suggestions advanced for possible additional areas of study.

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Injector design optimisation for SAGD conformance and cost

Injector design optimisation for SAGD conformance and cost

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SPE Thermal Well Integrity and design Symposium 2016

作者： Kaiser, T.M.v. Taubner, S.P. Noetic Engineering 2008 Inc. Canada

ISBN: (纸本)9781510844858

The "Soaker Hose" concept for SAGD injectors has long been a topic of interest for oil sands development, but few field trials have been attempted to date. The primary interest in this type of design is its potential to produce more uniform injection distributions, but other more elaborate solutions have garnered interest from the industry. Another, less prominent feature of the soaker hose concept is its potential for reducing well completion cost. In the current economic climate, the need for controlling cost has become paramount, which could make this design concept a subject of renewed interest for the industry. The basic premise of the soaker hose concept is to deliberately increase the radial flow resistance through the liner so that it dominates the overall flow resistance relative to the axial flow resistance in the wellbore, with a consequent reduction in radial flow variation. Some examples exploring the concept have been reported (e.g. Stalder, 2012). The performance interpretation is a product of the assumptions made to estimate the radial flow distribution, in particular the ideal formation conditions into which injection occurs. Modelling developments focused specifically on the SAGD process can shed new light on completion performance and provide more rigorous bases for optimizing completions that account for factors beyond wellbore hydraulics, including variances in drilling and reservoir performance. This paper presents results of SAGD modelling for various injector completion designs to quantify the potential for optimizing the recovery process. The Mechanistic SAGD Model incorporates coupled injector/ producer wellbore hydraulics with essential reservoir flow models to simulate SAGD conformance. It uses reservoir performance as input for directly calculating the liquid level distribution produced by the injector/producer completion configuration in the specific reservoir context. In this set of case studies, some variations on the soaker hose them

关键词： Oil sands

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The efficiency of GaN/AlGaN p-n heterostructures in Uv spectral range 3

The efficiency of GaN/AlGaN p-n heterostructures in UV spect...

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3rd International School and Conference on Optoelectronics, Photonics, engineering and Nanostructures (Saint Petersburg OPEN)

作者： Kurin, S. Yu Usikov, A. S. Papchenko, B. P. Helava, H. Makarov, Yu N. Evseenkov, A. S. Tarasov, S. A. Solomonov, A. v. Nitride Crystals AlN Ltd Pr Engelsa 27 St Petersburg 194156 Russia Univ ITMO Kronverkskiy Pr 49 St Petersburg 197101 Russia Nitride Crystals Inc 181 E Ind CourtSuite B Deer Pk NY 11729 USA St Petersburg Electrotech Univ LETI 5 Prof Popov Str St Petersburg 197376 Russia

GaN/AlGaN p-n heterostructures emitting in Uv spectral range obtained by HvPE approach were investigated. It was shown that the peak wavelength of Uv LEDs was in the range of 360-380 nm with FWHM of 10-13 nm. At operating current of 20 mA, the active region temperature T-j was 43 degrees C, the output optical power and efficiency - 1.14 mW and 1.46%, respectively. The model based on corpuscular Monte Carlo method for calculation of the light extraction index was presented. The simulation results allow us to propose the ways to increase the efficiency of Uv LEDs: surface interfaces texturing, optimization of the design of heterostructures, and the use of lenses.

关键词： Gallium nitride

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