Interconnection blocks with minimal dead volumes permitting planar interconnection to thin microfluidic devices

DEFF Research Database (Denmark)

Sabourin, David; Snakenborg, Detlef; Dufva, Martin

2010-01-01

We have previously described 'Interconnection Blocks' which are re-usable, non-integrated PDMS blocks which allowing multiple, aligned and planar microfluidic interconnections. Here, we describe Interconnection Block versions with zero dead volumes that allow fluidic interfacing to flat or thin s...

Analytical solutions for prediction of the ignition time of wood particles based on a time and space integral method

NARCIS (Netherlands)

Haseli, Y.; Oijen, van J.A.; Goey, de L.P.H.

2012-01-01

The main idea of this paper is to establish a simple approach for prediction of the ignition time of a wood particle assuming that the thermo-physical properties remain constant and ignition takes place at a characteristic ignition temperature. Using a time and space integral method, explicit

Optical interconnects

CERN Document Server

Chen, Ray T

2006-01-01

This book describes fully embedded board level optical interconnect in detail including the fabrication of the thin-film VCSEL array, its characterization, thermal management, the fabrication of optical interconnection layer, and the integration of devices on a flexible waveguide film. All the optical components are buried within electrical PCB layers in a fully embedded board level optical interconnect. Therefore, we can save foot prints on the top real estate of the PCB and relieve packaging difficulty reduced by separating fabrication processes. To realize fully embedded board level optical

Electromigration in integrated circuit interconnects studied by X-ray microscopy

Energy Technology Data Exchange (ETDEWEB)

Schneider, G. E-mail: gschnei1@gwdg.de; Denbeaux, G.; Anderson, E.; Bates, W.; Salmassi, F.; Nachimuthu, P.; Pearson, A.; Richardson, D.; Hambach, D.; Hoffmann, N.; Hasse, W.; Hoffmann, K

2003-01-01

To study mass transport phenomena in advanced microelectronic devices with X-rays requires penetration of dielectric and Si layers up to 30 {mu}m thick. X-ray imaging at 1.8 keV photon energy provides a high amplitude contrast between Cu or Al interconnects and dielectric layers and can penetrate through the required thickness. To perform X-ray microscopy at 1.8 keV, a new Ru/Si multilayer was designed for the transmission X-ray microscope XM-1 installed at the Advanced Light Source in Berkeley. The mass flow in a passivated Cu interconnect was studied at current densities up to 10{sup 7} A/cm{sup 2}. In addition, we demonstrated the high material contrast from different elements in integrated circuits with a resolution of about 40 nm.

Electromigration in integrated circuit interconnects studied by X-ray microscopy

CERN Document Server

Schneider, G; Anderson, E; Bates, W; Salmassi, F; Nachimuthu, P; Pearson, A; Richardson, D; Hambach, D; Hoffmann, N; Hasse, W; Hoffmann, K

2003-01-01

To study mass transport phenomena in advanced microelectronic devices with X-rays requires penetration of dielectric and Si layers up to 30 mu m thick. X-ray imaging at 1.8 keV photon energy provides a high amplitude contrast between Cu or Al interconnects and dielectric layers and can penetrate through the required thickness. To perform X-ray microscopy at 1.8 keV, a new Ru/Si multilayer was designed for the transmission X-ray microscope XM-1 installed at the Advanced Light Source in Berkeley. The mass flow in a passivated Cu interconnect was studied at current densities up to 10 sup 7 A/cm sup 2. In addition, we demonstrated the high material contrast from different elements in integrated circuits with a resolution of about 40 nm.

A full-duplex working integrated optoelectronic device for optical interconnect

Science.gov (United States)

Liu, Kai; Fan, Huize; Huang, Yongqing; Duan, Xiaofeng; Wang, Qi; Ren, Xiaomin; Wei, Qi; Cai, Shiwei

2018-05-01

In this paper, a full-duplex working integrated optoelectronic device is proposed. It is constructed by integrating a vertical cavity surface emitting laser (VCSEL) unit above a resonant cavity enhanced photodetector (RCE-PD) unit. Analysis shows that, the VCSEL unit has a threshold current of 1 mA and a slop efficiency of 0.66 W/A at 849.7 nm, the RCE-PD unit obtains its maximal absorption quantum efficiency of 90.24% at 811 nm with a FWHM of 4 nm. Moreover, the two units of the proposed integrated device can work independently from each other. So that the proposed integrated optoelectronic device can work full-duplex. It can be applied for single fiber bidirectional optical interconnects system.

Ignition experiment - alternatives

International Nuclear Information System (INIS)

Knobloch, A.F.

1979-10-01

This report comprises three short papers on cost estimates, integral burn time and alternative versions of Tokamak ignition experiments. These papers were discussed at the ZEPHYR workshop with participants from IPP Garching, MIT Cambridge and PPPL Princeton (Garching July 30 - August 2 1979) (Chapters A, B, C). It is shown, that starting from a practical parameter independent minimum integral burn time of Tokamak ignition experiments (some 10 3 s) by adding a shield for protection of the magnet insulation (permitted neutron dose 10 9 rad) an integral burn time of some 10 4 s can be achieved for only about 30% more outlay. For a substantially longer integral burn time the outlay approaches rather quickly that for a Tokamak reactor. Some examples for alternatives to ZEPHYR are being given, including some with low or no compression. In a further chapter D some early results of evaluating an ignition experiment on the basis of the energy confinement scaling put forward by Coppi and Mazzucato are presented. As opposed to the case of the Alcator scaling used in chapters A through C the minimum integral burn time of Tokamak ignition experiments here depends on the plasma current. Provided neutral injectors up to about 160 keV are available compression boosting is not required with this scaling. The results presented have been obtained neglecting the effects of the toroidal field ripple. (orig.) 891 HT/orig. 892 RKD [de

Optical Characteristics of a Multichannel Hybrid Integrated Light Source for Ultra-High-Bandwidth Optical Interconnections

Directory of Open Access Journals (Sweden)

Takanori Shimizu

2015-11-01

Full Text Available The optical characteristics of a multi-channel hybrid integrated light source were described for an optical interconnection with a bandwidth of over 10 Tbit/s. The power uniformity of the relative intensity of a 1000-channel light source was shown, and the minimum standard deviation s of the optical power of the 200 output ports at each 25-channel laser diode (LD array was estimated to be 0.49 dB. This hybrid integrated light source is expected to be easily adaptable to a photonics-electronics convergence system for ultra-high-bandwidth interchip interconnections.

Three-dimensional crossbar interconnection using planar-integrated free-space optics and digital mirror-device

Science.gov (United States)

Lohmann, U.; Jahns, J.; Limmer, S.; Fey, D.

2011-01-01

We consider the implementation of a dynamic crossbar interconnect using planar-integrated free-space optics (PIFSO) and a digital mirror-device™ (DMD). Because of the 3D nature of free-space optics, this approach is able to solve geometrical problems with crossings of the signal paths that occur in waveguide optical and electrical interconnection, especially for large number of connections. The DMD device allows one to route the signals dynamically. Due to the large number of individual mirror elements in the DMD, different optical path configurations are possible, thus offering the chance for optimizing the network configuration. The optimization is achieved by using an evolutionary algorithm for finding best values for a skewless parallel interconnection. Here, we present results and experimental examples for the use of the PIFSO/DMD-setup.

Carbon nanotubes for interconnects process, design and applications

CERN Document Server

Dijon, Jean; Maffucci, Antonio

2017-01-01

This book provides a single-source reference on the use of carbon nanotubes (CNTs) as interconnect material for horizontal, on-chip and 3D interconnects. The authors demonstrate the uses of bundles of CNTs, as innovative conducting material to fabricate interconnect through-silicon vias (TSVs), in order to improve the performance, reliability and integration of 3D integrated circuits (ICs). This book will be first to provide a coherent overview of exploiting carbon nanotubes for 3D interconnects covering aspects from processing, modeling, simulation, characterization and applications. Coverage also includes a thorough presentation of the application of CNTs as horizontal on-chip interconnects which can potentially revolutionize the nanoelectronics industry. This book is a must-read for anyone interested in the state-of-the-art on exploiting carbon nanotubes for interconnects for both 2D and 3D integrated circuits. Provides a single-source reference on carbon nanotubes for interconnect applications; Includes c...

High Density Interconnect Microstrip Patch Antenna for 5G Base Stations with Integrated Filtering Performance

Directory of Open Access Journals (Sweden)

Marco Salucci

2018-04-01

Full Text Available The elementary radiator of a planar array for next generation millimeter-wave (mm-wave 5G base stations is described. The antenna is designed for high density interconnect (HDI manufacturing for yielding a compact, densely-interconnected, and highly-integrable stacked structure. The layout of the single element is determined by directly optimizing key radiation features of the whole planar arrangement according to specific application-driven requirements. In addition, thanks to the exploitation of a spline-shaped modelling of the radiator, suitable performance in terms of impedance matching, realized gain, half-power beamwidth (HPBW, polarization purity, and inter-element isolation are achieved within the 28-GHz pass-band. Moreover, integrated out-of-band filtering capabilities are obtained in selected and wide non-contiguous stop-bands without additional circuitry.

A one-semester course in modeling of VSLI interconnections

CERN Document Server

Goel, Ashok

2015-01-01

Quantitative understanding of the parasitic capacitances and inductances, and the resultant propagation delays and crosstalk phenomena associated with the metallic interconnections on the very large scale integrated (VLSI) circuits has become extremely important for the optimum design of the state-of-the-art integrated circuits. More than 65 percent of the delays on the integrated circuit chip occur in the interconnections and not in the transistors on the chip. Mathematical techniques to model the parasitic capacitances, inductances, propagation delays, crosstalk noise, and electromigration-induced failure associated with the interconnections in the realistic high-density environment on a chip will be discussed. A One-Semester Course in Modeling of VLSI Interconnections also includes an overview of the future interconnection technologies for the nanotechnology circuits.

Tomography of integrated circuit interconnect with an electromigration void

Energy Technology Data Exchange (ETDEWEB)

Levine, Zachary H. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8410 (United States); Rensselaer Polytechnic Institute, Troy, New York 12180-3590 (United States); Kalukin, Andrew R. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8410 (United States); Kuhn, Markus [Intel Corporation RA1-329, 5200 Northeast Elam Young Parkway, Hillsboro, Oregon 74124 (United States); Frigo, Sean P. [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); McNulty, Ian [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Retsch, Cornelia C. [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Wang, Yuxin [Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Arp, Uwe [National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8410 (United States); Lucatorto, Thomas B. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8410 (United States); Ravel, Bruce D. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8410 (United States)] (and others)

2000-05-01

An integrated circuit interconnect was subject to accelerated-life test conditions to induce an electromigration void. The silicon substrate was removed, leaving only the interconnect test structure encased in silica. We imaged the sample with 1750 eV photons using the 2-ID-B scanning transmission x-ray microscope at the Advanced Photon Source, a third-generation synchrotron facility. Fourteen views through the sample were obtained over a 170 degree sign range of angles (with a 40 degree sign gap) about a single rotation axis. Two sampled regions were selected for three-dimensional reconstruction: one of the ragged end of a wire depleted by the void, the other of the adjacent interlevel connection (or ''via''). We applied two reconstruction techniques: the simultaneous iterative reconstruction technique and a Bayesian reconstruction technique, the generalized Gaussian Markov random field method. The stated uncertainties are total, with one standard deviation, which resolved the sample to 200{+-}70 and 140{+-}30 nm, respectively. The tungsten via is distinguished from the aluminum wire by higher absorption. Within the void, the aluminum is entirely depleted from under the tungsten via. The reconstructed data show the applicability of this technique to three-dimensional imaging of buried defects in submicrometer structures relevant to the microelectronics industry. (c) 2000 American Institute of Physics.

Optimal interconnection and renewable targets for north-west Europe

International Nuclear Information System (INIS)

Lynch, Muireann Á.; Tol, Richard S.J.; O'Malley, Mark J.

2012-01-01

We present a mixed-integer, linear programming model for determining optimal interconnection for a given level of renewable generation using a cost minimisation approach. Optimal interconnection and capacity investment decisions are determined under various targets for renewable penetration. The model is applied to a test system for eight regions in Northern Europe. It is found that considerations on the supply side dominate demand side considerations when determining optimal interconnection investment: interconnection is found to decrease generation capacity investment and total costs only when there is a target for renewable generation. Higher wind integration costs see a concentration of wind in high-wind regions with interconnection to other regions. - Highlights: ► We use mixed-integer linear programming to determine optimal interconnection locations for given renewable targets. ► The model is applied to a test system for eight regions in Northern Europe. ► Interconnection reduces costs only when there is a renewable target. ► Wind integration costs affect the interconnection portfolio.

Analytical solutions for prediction of the ignition time of wood particles based on a time and space integral method

International Nuclear Information System (INIS)

Haseli, Y.; Oijen, J.A. van; Goey, L.P.H. de

2012-01-01

Highlights: ► A simple model for prediction of the ignition time of a wood particle is presented. ► The formulation is given for both thermally thin and thermally thick particles. ► Transition from thermally thin to thick regime occurs at a critical particle size. ► The model is validated against a numerical model and various experimental data. - Abstract: The main idea of this paper is to establish a simple approach for prediction of the ignition time of a wood particle assuming that the thermo-physical properties remain constant and ignition takes place at a characteristic ignition temperature. Using a time and space integral method, explicit relationships are derived for computation of the ignition time of particles of three common shapes (slab, cylinder and sphere), which may be characterized as thermally thin or thermally thick. It is shown through a dimensionless analysis that the dimensionless ignition time can be described as a function of non-dimensional ignition temperature, reactor temperature or external incident heat flux, and parameter K which represents the ratio of conduction heat transfer to the external radiation heat transfer. The numerical results reveal that for the dimensionless ignition temperature between 1.25 and 2.25 and for values of K up to 8000 (corresponding to woody materials), the variation of the ignition time of a thermally thin particle with K and the dimensionless ignition temperature is linear, whereas the dependence of the ignition time of a thermally thick particle on the above two parameters obeys a quadratic function. Furthermore, it is shown that the transition from the regime of thermally thin to the regime of thermally thick occurs at K cr (corresponding to a critical size of particle) which is found to be independent of the particle shape. The model is validated by comparing the predicted and the measured ignition time of several wood particles obtained from different sources. Good agreement is achieved which

Numerical Analysis of the Interaction between Thermo-Fluid Dynamics and Auto-Ignition Reaction in Spark Ignition Engines

Science.gov (United States)

Saijyo, Katsuya; Nishiwaki, Kazuie; Yoshihara, Yoshinobu

The CFD simulations were performed integrating the low-temperature oxidation reaction. Analyses were made with respect to the first auto-ignition location in the case of a premixed-charge compression auto-ignition in a laminar flow field and in the case of the auto-ignition in an end gas during an S. I. Engine combustion process. In the latter simulation, the spatially-filtered transport equations were solved to express fluctuating temperatures in a turbulent flow in consideration of strong non-linearity to temperature in the reaction equations. It is suggested that the first auto-ignition location does not always occur at higher-temperature locations and that the difference in the locations of the first auto-ignition depends on the time period during which the local end gas temperature passes through the region of shorter ignition delay, including the NTC region.

Interconnection network architectures based on integrated orbital angular momentum emitters

Science.gov (United States)

Scaffardi, Mirco; Zhang, Ning; Malik, Muhammad Nouman; Lazzeri, Emma; Klitis, Charalambos; Lavery, Martin; Sorel, Marc; Bogoni, Antonella

2018-02-01

Novel architectures for two-layer interconnection networks based on concentric OAM emitters are presented. A scalability analysis is done in terms of devices characteristics, power budget and optical signal to noise ratio by exploiting experimentally measured parameters. The analysis shows that by exploiting optical amplifications, the proposed interconnection networks can support a number of ports higher than 100. The OAM crosstalk induced-penalty, evaluated through an experimental characterization, do not significantly affect the interconnection network performance.

Distributed Energy Resources Interconnection Systems: Technology Review and Research Needs

Energy Technology Data Exchange (ETDEWEB)

Friedman, N. R.

2002-09-01

Interconnecting distributed energy resources (DER) to the electric utility grid (or Area Electric Power System, Area EPS) involves system engineering, safety, and reliability considerations. This report documents US DOE Distribution and Interconnection R&D (formerly Distributed Power Program) activities, furthering the development and safe and reliable integration of DER interconnected with our nation's electric power systems. The key to that is system integration and technology development of the interconnection devices that perform the functions necessary to maintain the safety, power quality, and reliability of the EPS when DER are connected to it.

Multi-net optimization of VLSI interconnect

CERN Document Server

Moiseev, Konstantin; Wimer, Shmuel

2015-01-01

This book covers layout design and layout migration methodologies for optimizing multi-net wire structures in advanced VLSI interconnects. Scaling-dependent models for interconnect power, interconnect delay and crosstalk noise are covered in depth, and several design optimization problems are addressed, such as minimization of interconnect power under delay constraints, or design for minimal delay in wire bundles within a given routing area. A handy reference or a guide for design methodologies and layout automation techniques, this book provides a foundation for physical design challenges of interconnect in advanced integrated circuits.  • Describes the evolution of interconnect scaling and provides new techniques for layout migration and optimization, focusing on multi-net optimization; • Presents research results that provide a level of design optimization which does not exist in commercially-available design automation software tools; • Includes mathematical properties and conditions for optimal...

Cross-border versus cross-sector interconnectivity in renewable energy systems

International Nuclear Information System (INIS)

Thellufsen, Jakob Zinck; Lund, Henrik

2017-01-01

In the transition to renewable energy systems, fluctuating renewable energy, such as wind and solar power, plays a large and important role. This creates a challenge in terms of meeting demands, as the energy production fluctuates based on weather patterns. To utilise high amounts of fluctuating renewable energy, the energy system has to be more flexible in terms of decoupling demand and production. This paper investigates two potential ways to increase flexibility. The first is the interconnection between energy systems, for instance between two countries, labelled as cross-border interconnection, and the second is cross-sector interconnection, i.e., the integration between different parts of an energy system, for instance heat and electricity. This paper seeks to compare the types of interconnectivity and discuss to which extent they are mutually beneficial. To do this, the study investigates two energy systems that represent Northern and Southern Europe. Both systems go through three developmental steps that increase the cross-sector interconnectivity. At each developmental step an increasing level of transmission capacities is examined to identify the benefits of cross-border interconnectivity. The results show that while both measures increase the system utilisation of renewable energy and the system efficiency, the cross-sector interconnection gives the best system performance. To analyse the possible interaction between cross-sector and cross-border interconnectivity, two main aspects have to be clarified. The first part defines the approach and the second is the construction of the two archetypes. - Highlights: • A method to investigate system integration and system interconnection is suggested. • The implementation is investigated across a Northern and Southern energy system. • The study identifies benefits of system integration and system interconnection. • The performance of the energy system benefits most from system integration.

Effect of flow velocity and temperature on ignition characteristics in laser ignition of natural gas and air mixtures

Science.gov (United States)

Griffiths, J.; Riley, M. J. W.; Borman, A.; Dowding, C.; Kirk, A.; Bickerton, R.

2015-03-01

Laser induced spark ignition offers the potential for greater reliability and consistency in ignition of lean air/fuel mixtures. This increased reliability is essential for the application of gas turbines as primary or secondary reserve energy sources in smart grid systems, enabling the integration of renewable energy sources whose output is prone to fluctuation over time. This work details a study into the effect of flow velocity and temperature on minimum ignition energies in laser-induced spark ignition in an atmospheric combustion test rig, representative of a sub 15 MW industrial gas turbine (Siemens Industrial Turbomachinery Ltd., Lincoln, UK). Determination of minimum ignition energies required for a range of temperatures and flow velocities is essential for establishing an operating window in which laser-induced spark ignition can operate under realistic, engine-like start conditions. Ignition of a natural gas and air mixture at atmospheric pressure was conducted using a laser ignition system utilizing a Q-switched Nd:YAG laser source operating at 532 nm wavelength and 4 ns pulse length. Analysis of the influence of flow velocity and temperature on ignition characteristics is presented in terms of required photon flux density, a useful parameter to consider during the development laser ignition systems.

Robustness studies of ignition targets for the National Ignition Facility in two dimensions

International Nuclear Information System (INIS)

Clark, Daniel S.; Haan, Steven W.; Salmonson, Jay D.

2008-01-01

Inertial confinement fusion capsules are critically dependent on the integrity of their hot spots to ignite. At the time of ignition, only a certain fractional perturbation of the nominally spherical hot spot boundary can be tolerated and the capsule still achieve ignition. The degree to which the expected hot spot perturbation in any given capsule design is less than this maximum tolerable perturbation is a measure of the ignition margin or robustness of that design. Moreover, since there will inevitably be uncertainties in the initial character and implosion dynamics of any given capsule, all of which can contribute to the eventual hot spot perturbation, quantifying the robustness of that capsule against a range of parameter variations is an important consideration in the capsule design. Here, the robustness of the 300 eV indirect drive target design for the National Ignition Facility [Lindl et al., Phys. Plasmas 11, 339 (2004)] is studied in the parameter space of inner ice roughness, implosion velocity, and capsule scale. A suite of 2000 two-dimensional simulations, run with the radiation hydrodynamics code LASNEX, is used as the data base for the study. For each scale, an ignition region in the two remaining variables is identified and the ignition cliff is mapped. In accordance with the theoretical arguments of Levedahl and Lindl [Nucl. Fusion 37, 165 (1997)] and Kishony and Shvarts [Phys. Plasmas 8, 4925 (2001)], the location of this cliff is fitted to a power law of the capsule implosion velocity and scale. It is found that the cliff can be quite well represented in this power law form, and, using this scaling law, an assessment of the overall (one- and two-dimensional) ignition margin of the design can be made. The effect on the ignition margin of an increase or decrease in the density of the target fill gas is also assessed

Electricity and gas interconnections in France. A tool for the construction of an integrated European market

International Nuclear Information System (INIS)

2016-06-01

The French Energy Regulator (CRE) is publishing its report on French electricity and gas interconnections. The report makes two main conclusions: French electricity and natural gas networks are well interconnected with their counterparts in neighbouring countries and the use of interconnections has been significantly improved over the last 10 years. In terms of electricity, France's average export capacity is 13.5 GW, i.e. more than 10% of its production capacity. France is very well integrated in the European gas market and is a transit country to Spain and Italy. It has boosted its interconnection capacity in gas by 40% in 10 years. Interconnections are vital to the internal energy market and help trade between Member States. They enable European consumers to benefit from cost-effective energy by diversifying sources of supply. Since it was created, the CRE has played a leading role in this area, by fostering the development of interconnections at the French borders and by making them more efficiently used. After major efforts, the question of creating new interconnections (which constitute complex and costly projects) is now being raised. In terms of gas, the Midcat Project (a new gas interconnection between France and Spain) provides a good illustration of this question. The project will cost almost 3 billion Euros, two billion of which is being funded by France, and the decision to launch it should not be taken lightly without robust cost-benefit analyses. These studies must, in particular, identify and quantify the benefits for each country concerned as well as for the European Union, and organise the project funding in relation to these benefits. As concerns the interconnection project in the Bay of Biscay between France and Spain, overcoming technical uncertainties is an essential prerequisite before commenting on the opportunities it offers in terms of the costs and benefits that it might generate. In compliance with the law, the CRE acts on behalf of

Magnetically Assisted Fast Ignition

OpenAIRE

Wang, W.-M.; Gibbon, P.; Sheng, Z.-M.; Li, Y.-T.

2015-01-01

Fast ignition (FI) is investigated via integrated particle-in-cell simulation including both generation andtransport of fast electrons, where petawatt ignition lasers of 2 ps and compressed targets of a peak density of300 g cm−3 and areal density of 0.49 g cm−2 at the core are taken. When a 20 MG static magnetic field isimposed across a conventional cone-free target, the energy coupling from the laser to the core is enhancedby sevenfold and reaches 14%. This value even exceeds that obtained u...

Performance evaluation of multi-stratum resources integrated resilience for software defined inter-data center interconnect.

Science.gov (United States)

Yang, Hui; Zhang, Jie; Zhao, Yongli; Ji, Yuefeng; Wu, Jialin; Lin, Yi; Han, Jianrui; Lee, Young

2015-05-18

Inter-data center interconnect with IP over elastic optical network (EON) is a promising scenario to meet the high burstiness and high-bandwidth requirements of data center services. In our previous work, we implemented multi-stratum resources integration among IP networks, optical networks and application stratums resources that allows to accommodate data center services. In view of this, this study extends to consider the service resilience in case of edge optical node failure. We propose a novel multi-stratum resources integrated resilience (MSRIR) architecture for the services in software defined inter-data center interconnect based on IP over EON. A global resources integrated resilience (GRIR) algorithm is introduced based on the proposed architecture. The MSRIR can enable cross stratum optimization and provide resilience using the multiple stratums resources, and enhance the data center service resilience responsiveness to the dynamic end-to-end service demands. The overall feasibility and efficiency of the proposed architecture is experimentally verified on the control plane of our OpenFlow-based enhanced SDN (eSDN) testbed. The performance of GRIR algorithm under heavy traffic load scenario is also quantitatively evaluated based on MSRIR architecture in terms of path blocking probability, resilience latency and resource utilization, compared with other resilience algorithms.

Packaging and interconnection for superconductive circuitry

International Nuclear Information System (INIS)

Anacker, W.

1976-01-01

A three dimensional microelectronic module packaged for reduced signal propagation delay times including a plurality of circuit carrying means, which may comprise unbacked chips, with integrated superconductive circuitry thereon is described. The circuit carrying means are supported on their edges and have contact lands in the vicinity of, or at, the edges to provide for interconnecting circuitry. The circuit carrying means are supported by supporting means which include slots to provide a path for interconnection wiring to contact the lands of the circuit carrying means. Further interconnecting wiring may take the form of integrated circuit wiring on the reverse side of the supporting means. The low heat dissipation of the superconductive circuitry allows the circuit carrying means to be spaced approximately no less than 30 mils apart. The three dimensional arrangement provides lower random propagation delays than would a planar array of circuits

High-density hybrid interconnect methodologies

International Nuclear Information System (INIS)

John, J.; Zimmermann, L.; Moor, P.De; Hoof, C.Van

2003-01-01

Full text: The presentation gives an overview of the state-of-the-art of hybrid integration and in particular the IMEC technological approaches that will be able to address future hybrid detector needs. The dense hybrid flip-chip integration of an array of detectors and its dedicated readout electronics can be achieved with a variety of solderbump techniques such as pure Indium or Indium alloys, Ph-In, Ni/PbSn, but also conducting polymers... Particularly for cooled applications or ultra-high density applications, Indium solderbump technology (electroplated or evaporated) is the method of choice. The state-of-the-art of solderbump technologies that are to a high degree independent of the underlying detector material will be presented and examples of interconnect densities between 5x1E4cm-2 and 1x1E6 cm-2 will be demonstrated. For several classes of detectors, flip-chip integration is not allowed since the detectors have to be illuminated from the top. This applies to image sensors for EUV applications such as GaN/AlGaN based detectors and to MEMS-based sensors. In such cases, the only viable interconnection method has to be through the (thinned) detector wafer followed by a solderbump-based integration. The approaches for dense and ultra-dense through-the-wafer interconnect 'vias' will be presented and wafer thinning approaches will be shown

Evaluation of the Revolver Ignition Design at the National Ignition Facility Using Polar-Direct-Drive Illumination

Science.gov (United States)

McKenty, P. W.; Collins, T. J. B.; Marozas, J. A.; Campbell, E. M.; Molvig, K.; Schmitt, M.

2017-10-01

The direct-drive ignition design Revolver employs a triple-shell target using a beryllium ablator, a copper driver, and an eventual gold pusher. Symmetric numerical calculations indicate that each of the three shells exhibit low convergence ( 3to 5) resulting in a modest gain (G 4) for 1.7 MJ of incident laser energy. Studies are now underway to evaluate the robustness of this design employing polar direct drive (PDD) at the National Ignition Facility. Integral to these calculations is the leveraging of illumination conditioning afforded by research done to demonstrate ignition for a traditional PDD hot-spot target design. Two-dimensional simulation results, employing nonlocal electron-thermal transport and cross-beam energy transport, will be presented that indicate ignition using PDD. A study of the allowed levels of long-wavelength perturbations (target offset and power imbalance) not precluding ignition will also be examined. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Integrated thermodynamic model for ignition target performance

Directory of Open Access Journals (Sweden)

Springer P.T.

2013-11-01

Full Text Available We have derived a 3-dimensional synthetic model for NIF implosion conditions, by predicting and optimizing fits to a broad set of x-ray and nuclear diagnostics obtained on each shot. By matching x-ray images, burn width, neutron time-of-flight ion temperature, yield, and fuel ρr, we obtain nearly unique constraints on conditions in the hotspot and fuel in a model that is entirely consistent with the observables. This model allows us to determine hotspot density, pressure, areal density (ρr, total energy, and other ignition-relevant parameters not available from any single diagnostic. This article describes the model and its application to National Ignition Facility (NIF tritium–hydrogen–deuterium (THD and DT implosion data, and provides an explanation for the large yield and ρr degradation compared to numerical code predictions.

Numerical research of heat and mass transfer during low-temperature ignition of a coal particle

Directory of Open Access Journals (Sweden)

Glushkov Dmitrii O.

2015-01-01

Full Text Available Numerical researches have been carried out to study the influence of air flow temperature and a fossil fuel particle rate on sufficient conditions of ignition in a “coal particle - air” system. Developed mathematical model takes into account interconnected processes of heat transfer in a coal particle and gas area, thermal decomposition of organic material, diffusion and gas-phase oxidation of volatiles, heating of a coke (carbon and its heterogeneous ignition. The effect of low-temperature (about 600 K ignition for a single coal particle is impossible even at variation of its rate (radius from 0.05 mm to 0.5 mm. Nevertheless this process is possible for group of particles (two, three, et al. situated at close-range from each other. The physical aspects of the problem are discussed.

Metal-interconnection-free integration of InGaN/GaN light emitting diodes with AlGaN/GaN high electron mobility transistors

Energy Technology Data Exchange (ETDEWEB)

Liu, Chao; Cai, Yuefei; Liu, Zhaojun; Ma, Jun; Lau, Kei May, E-mail: eekmlau@ust.hk [Photonics Technology Center, Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

2015-05-04

We report a metal-interconnection-free integration scheme for InGaN/GaN light emitting diodes (LEDs) and AlGaN/GaN high electron mobility transistors (HEMTs) by combining selective epi removal (SER) and selective epitaxial growth (SEG) techniques. SER of HEMT epi was carried out first to expose the bottom unintentionally doped GaN buffer and the sidewall GaN channel. A LED structure was regrown in the SER region with the bottom n-type GaN layer (n-electrode of the LED) connected to the HEMTs laterally, enabling monolithic integration of the HEMTs and LEDs (HEMT-LED) without metal-interconnection. In addition to saving substrate real estate, minimal interface resistance between the regrown n-type GaN and the HEMT channel is a significant improvement over metal-interconnection. Furthermore, excellent off-state leakage characteristics of the driving transistor can also be guaranteed in such an integration scheme.

Metal-interconnection-free integration of InGaN/GaN light emitting diodes with AlGaN/GaN high electron mobility transistors

International Nuclear Information System (INIS)

Liu, Chao; Cai, Yuefei; Liu, Zhaojun; Ma, Jun; Lau, Kei May

2015-01-01

We report a metal-interconnection-free integration scheme for InGaN/GaN light emitting diodes (LEDs) and AlGaN/GaN high electron mobility transistors (HEMTs) by combining selective epi removal (SER) and selective epitaxial growth (SEG) techniques. SER of HEMT epi was carried out first to expose the bottom unintentionally doped GaN buffer and the sidewall GaN channel. A LED structure was regrown in the SER region with the bottom n-type GaN layer (n-electrode of the LED) connected to the HEMTs laterally, enabling monolithic integration of the HEMTs and LEDs (HEMT-LED) without metal-interconnection. In addition to saving substrate real estate, minimal interface resistance between the regrown n-type GaN and the HEMT channel is a significant improvement over metal-interconnection. Furthermore, excellent off-state leakage characteristics of the driving transistor can also be guaranteed in such an integration scheme

Interconnecting heterogeneous database management systems

Science.gov (United States)

Gligor, V. D.; Luckenbaugh, G. L.

1984-01-01

It is pointed out that there is still a great need for the development of improved communication between remote, heterogeneous database management systems (DBMS). Problems regarding the effective communication between distributed DBMSs are primarily related to significant differences between local data managers, local data models and representations, and local transaction managers. A system of interconnected DBMSs which exhibit such differences is called a network of distributed, heterogeneous DBMSs. In order to achieve effective interconnection of remote, heterogeneous DBMSs, the users must have uniform, integrated access to the different DBMs. The present investigation is mainly concerned with an analysis of the existing approaches to interconnecting heterogeneous DBMSs, taking into account four experimental DBMS projects.

Progress Toward Ignition on the National Ignition Facility

International Nuclear Information System (INIS)

Kauffman, R.L.

2011-01-01

pulse lengths produce unique plasma conditions for laser-plasma instabilities that could reduce hohlraum coupling efficiency. Initial experiments have demonstrated efficient coupling of laser energy to x-rays. X-ray drive greater than 300 eV has been measured in gas-filled ignition hohlraum and shows the expected scaling with laser energy and hohlraum scale size. Experiments are now optimizing capsule implosions for ignition. Ignition conditions require assembling the fuel with sufficient density and temperature for thermonuclear burn. X-rays ablate the outside of the capsule, accelerating and spherically compressing the capsule for assembling the fuel. The implosion stagnates, heating the central core and producing a hot spot that ignites and burns the surrounding fuel. The four main characteristics of the implosion are shell velocity, central hot spot shape, fuel adiabat, and mix. Experiments studying these four characteristics of implosions are used to optimize the implosion. Integrated experiments using cryogenic fuel layer experiments demonstrate the quality of the implosion as the optimization experiments progress. The final compressed fuel conditions are diagnosed by measuring the x-ray emission from the hot core and the neutrons and charged particles produced in the fusion reactions. Metrics of the quality of the implosion are the neutron yield and the shell areal density, as well as the size and shape of the core. The yield depends on the amount of fuel in the hot core and its temperature and is a gauge of the energy coupling to the fuel. The areal density, the density of the fuel times its thickness, diagnoses the fuel assembly, which is measured using the fraction of neutrons that are down scattered passing through the dense shell. The yield and fraction of down scattered neutrons, or shell rho-r, from the cryogenic layered implosions are shown in Figure 3. The different sets of data represent results after a series of implosion optimization experiments. Both

Simultaneous measurement of ignition energy and current signature for brush discharges

International Nuclear Information System (INIS)

Fast, Lars; Andersson, Birgitta; Smallwood, Jeremy; Holdstock, Paul; Paasi, Jaakko

2011-01-01

Accurate prediction of the probability of ignition arising from charged insulators is a crucial element of risk assessment in process industry. Incendiary brush discharges can occur when a large or grounded conductor approaches a charged insulator in the presence of a flammable atmosphere. This paper describes ignition tests based on an IEC standard method and simultaneously recorded temporal distribution of current released in the discharges, using a discharge probe integrated with the ignition probe. Ignition and non-ignition results are compared with peak discharge current and charge transferred in the discharge. No clear ignition threshold was found for either of these parameters. No major differences were found between igniting and non-igniting waveforms.

Review of the National Ignition Campaign 2009-2012

International Nuclear Information System (INIS)

Lindl, John; Landen, Otto; Edwards, John; Moses, Ed

2014-01-01

The National Ignition Campaign (NIC) was a multi-institution effort established under the National Nuclear Security Administration of DOE in 2005, prior to the completion of the National Ignition Facility (NIF) in 2009. The scope of the NIC was the planning and preparation for and the execution of the first 3 yr of ignition experiments (through the end of September 2012) as well as the development, fielding, qualification, and integration of the wide range of capabilities required for ignition. Besides the operation and optimization of the use of NIF, these capabilities included over 50 optical, x-ray, and nuclear diagnostic systems, target fabrication facilities, experimental platforms, and a wide range of NIF facility infrastructure. The goal of ignition experiments on the NIF is to achieve, for the first time, ignition and thermonuclear burn in the laboratory via inertial confinement fusion and to develop a platform for ignition and high energy density applications on the NIF. The goal of the NIC was to develop and integrate all of the capabilities required for a precision ignition campaign and, if possible, to demonstrate ignition and gain by the end of FY12. The goal of achieving ignition can be divided into three main challenges. The first challenge is defining specifications for the target, laser, and diagnostics with the understanding that not all ignition physics is fully understood and not all material properties are known. The second challenge is designing experiments to systematically remove these uncertainties. The third challenge is translating these experimental results into metrics designed to determine how well the experimental implosions have performed relative to expectations and requirements and to advance those metrics toward the conditions required for ignition. This paper summarizes the approach taken to address these challenges, along with the progress achieved to date and the challenges that remain. At project completion in 2009, NIF lacked

Ignition and fusion burn in fast ignition scheme

International Nuclear Information System (INIS)

Takabe, Hideaki

1998-01-01

The target physics of fast ignition is briefly reviewed by focusing on the ignition and fusion burn in the off-center ignition scheme. By the use of a two dimensional hydrodynamic code with an alpha heating process, the ignition condition is studied. It is shown that the ignition condition of the off-center ignition scheme coincides with that of the the central isochoric model. After the ignition, a nuclear burning wave is seen to burn the cold main fuel with a velocity of 2 - 3 x 10 8 cm/s. The spark energy required for the off-center ignition is 2 - 3 kJ or 10 - 15 kJ for the core density of 400 g/cm 3 or 200 g/cm 3 , respectively. It is demonstrated that a core gain of more than 2,000 is possible for a core energy of 100 kJ with a hot spark energy of 13 kJ. The requirement for the ignition region's heating time is also discussed by modeling a heating source in the 2-D code. (author)

Ignition on the National Ignition Facility: a path towards inertial fusion energy

International Nuclear Information System (INIS)

Moses, Edward I.

2009-01-01

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is nearing completion at Lawrence Livermore National Laboratory (LLNL). NIF, a 192-beam Nd-glass laser facility, will produce 1.8 MJ, 500 TW of light at the third-harmonic, ultraviolet light of 351 nm. The NIF project is scheduled for completion in March 2009. Currently, all 192 beams have been operationally qualified and have produced over 4.0 MJ of light at the fundamental wavelength of 1053 nm, making NIF the world's first megajoule laser. The principal goal of NIF is to achieve ignition of a deuterium-tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy and for broader scientific applications. The plan is to begin 96-beam symmetric indirect-drive ICF experiments early in FY2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). This national effort to achieve fusion ignition is coordinated through a detailed plan that includes the science, technology and equipment such as diagnostics, cryogenic target manipulator and user optics required for ignition experiments. Participants in this effort include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational and integrated into the facility soon after project completion and to conduct a credible ignition campaign in 2010. When the NIF is complete, the long-sought goal of achieving self-sustaining nuclear fusion and energy gain in the laboratory will be much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of inertial fusion energy (IFE) and will likely focus

Ignition on the National Ignition Facility: a path towards inertial fusion energy

Science.gov (United States)

Moses, Edward I.

2009-10-01

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is nearing completion at Lawrence Livermore National Laboratory (LLNL). NIF, a 192-beam Nd-glass laser facility, will produce 1.8 MJ, 500 TW of light at the third-harmonic, ultraviolet light of 351 nm. The NIF project is scheduled for completion in March 2009. Currently, all 192 beams have been operationally qualified and have produced over 4.0 MJ of light at the fundamental wavelength of 1053 nm, making NIF the world's first megajoule laser. The principal goal of NIF is to achieve ignition of a deuterium-tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy and for broader scientific applications. The plan is to begin 96-beam symmetric indirect-drive ICF experiments early in FY2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). This national effort to achieve fusion ignition is coordinated through a detailed plan that includes the science, technology and equipment such as diagnostics, cryogenic target manipulator and user optics required for ignition experiments. Participants in this effort include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory and the University of Rochester Laboratory for Energetics (LLE). The primary goal for NIC is to have all of the equipment operational and integrated into the facility soon after project completion and to conduct a credible ignition campaign in 2010. When the NIF is complete, the long-sought goal of achieving self-sustaining nuclear fusion and energy gain in the laboratory will be much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of inertial fusion energy (IFE) and will likely focus

Optical Interconnects for Future Data Center Networks

CERN Document Server

Bergman, Keren; Tomkos, Ioannis

2013-01-01

Optical Interconnects for Future Data Center Networks covers optical networks and how they can provide high bandwidth, energy efficient interconnects with increased communication bandwidth. This volume, with contributions from leading researchers in the field, presents an integrated view of the expected future requirements of data centers and serves as a reference for some of the most advanced and promising solutions proposed by researchers from leading universities, research labs, and companies. The work also includes several novel architectures, each demonstrating different technologies such as optical circuits, optical switching, MIMO optical OFDM, and others. Additionally, Optical Interconnects for Future Data Center Networks provides invaluable insights into the benefits and advantages of optical interconnects and how they can be a promising alternative for future data center networks.

The national ignition facility: path to ignition in the laboratory

International Nuclear Information System (INIS)

Moses, E.I.; Bonanno, R.E.; Haynam, C.A.; Kauffman, R.L.; MacGowan, B.J.; Patterson Jr, R.W.; Sawicki, R.H.; Van Wonterghem, B.M.

2007-01-01

The National Ignition Facility (NIF) is a 192-beam laser facility presently under construction at Lawrence Livermore National Laboratory. When completed, NIF will be a 1.8-MJ, 500-TW ultraviolet laser system. Its missions are to obtain fusion ignition of deuterium-tritium plasmas in ICF (Inertial Confinement Fusion) targets and to perform high energy density experiments in support of the U.S. nuclear weapons stockpile. The NIF facility will consist of 2 laser bays, 4 capacitor areas, 2 laser switchyards, the target area and the building core. The laser is configured in 4 clusters of 48 beams, 2 in each laser bay. Four of the NIF beams have been already commissioned to demonstrate laser performance and to commission the target area including target and beam alignment and laser timing. During this time, NIF has demonstrated on a single-beam basis that it will meet its performance goals and has demonstrated its precision and flexibility for pulse shaping, pointing, timing and beam conditioning. It also performed 4 important experiments for ICF and High Energy Density Science. Presently, the project is installing production hardware to complete the project in 2009 with the goal to begin ignition experiments in 2010. An integrated plan has been developed including the NIF operations, user equipment such as diagnostics and cryogenic target capability, and experiments and calculations to meet this goal. This talk will provide NIF status, the plan to complete NIF, and the path to ignition. (authors)

Si micro photonics for optical interconnection

International Nuclear Information System (INIS)

Wada, K.; Ahn, D.H.; Lim, D.R.; Michel, J.; Kimerling, L.C.

2006-01-01

This paper reviews current status of silicon microphotonics and the recent prototype of on-chip optical interconnection. Si microphotonics pursues complementary metal oxide semiconductor (CMOS)-compatibility of photonic devices to reduce the materials diversity eventually to integrate on Si chips. Fractal optical H-trees have been implemented on a chip and found to be a technology breakthrough beyond metal interconnection. It has shown that large RC time constants associated with metal can be eliminated at least long distant data communication on a chip, and eventually improve yield and power issues. This has become the world's first electronic and photonic integrated circuits (EPICs) and the possibility of at least 10 GHz clocking for personal computers has been demonstrated

Confinement of ignition and yield on the National Ignition Facility

International Nuclear Information System (INIS)

Tobin, M.; Karpenko, V.; Foley, D.; Anderson, A.; Burnham, A.; Reitz, T.; Latkowski, J.; Bernat, T.

1996-01-01

The National Ignition Facility Target Areas and Experimental Systems has reached mid-Title I design. Performance requirements for the Target Area are reviewed and design changes since the Conceptual Design Report are discussed. Development activities confirm a 5-m radius chamber and the viability of a boron carbide first wall. A scheme for cryogenic target integration with the NIF Target Area is presented

Optical backplane interconnect switch for data processors and computers

Science.gov (United States)

Hendricks, Herbert D.; Benz, Harry F.; Hammer, Jacob M.

1989-01-01

An optoelectronic integrated device design is reported which can be used to implement an all-optical backplane interconnect switch. The switch is sized to accommodate an array of processors and memories suitable for direct replacement into the basic avionic multiprocessor backplane. The optical backplane interconnect switch is also suitable for direct replacement of the PI bus traffic switch and at the same time, suitable for supporting pipelining of the processor and memory. The 32 bidirectional switchable interconnects are configured with broadcast capability for controls, reconfiguration, and messages. The approach described here can handle a serial interconnection of data processors or a line-to-link interconnection of data processors. An optical fiber demonstration of this approach is presented.

Ignition delay time correlation of fuel blends based on Livengood-Wu description

KAUST Repository

Khaled, Fathi

2017-08-17

In this work, a universal methodology for ignition delay time (IDT) correlation of multicomponent fuel mixtures is reported. The method is applicable over wide ranges of temperatures, pressures, and equivalence ratios. n-Heptane, iso-octane, toluene, ethanol and their blends are investigated in this study because of their relevance to gasoline surrogate formulation. The proposed methodology combines benefits from the Livengood-Wu integral, the cool flame characteristics and the Arrhenius behavior of the high-temperature ignition delay time to suggest a simple and comprehensive formulation for correlating the ignition delay times of pure components and blends. The IDTs of fuel blends usually have complex dependences on temperature, pressure, equivalence ratio and composition of the blend. The Livengood-Wu integral is applied here to relate the NTC region and the cool flame phenomenon. The integral is further extended to obtain a relation between the IDTs of fuel blends and pure components. Ignition delay times calculated using the proposed methodology are in excellent agreement with those simulated using a detailed chemical kinetic model for n-heptane, iso-octane, toluene, ethanol and blends of these components. Finally, very good agreement is also observed for combustion phasing in homogeneous charge compression ignition (HCCI) predictions between simulations performed with detailed chemistry and calculations using the developed ignition delay correlation.

Probability of ignition - a better approach than ignition margin

International Nuclear Information System (INIS)

Ho, S.K.; Perkins, L.J.

1989-01-01

The use of a figure of merit - the probability of ignition - is proposed for the characterization of the ignition performance of projected ignition tokamaks. Monte Carlo and analytic models have been developed to compute the uncertainty distribution function for ignition of a given tokamak design, in terms of the uncertainties inherent in the tokamak physics database. A sample analysis with this method indicates that the risks of not achieving ignition may be unacceptably high unless the accepted margins for ignition are increased. (author). Letter-to-the-editor. 12 refs, 2 figs, 2 tabs

Resolving a central ICF issue for ignition: Implosion symmertry

International Nuclear Information System (INIS)

Cray, M.; Delamater, N.D.; Fernandez, J.C.

1994-01-01

The Los Alamos National Laboratory Inertial Confinement Fusion (ICF) Program focuses on resolving key target-physics issues and developing technology needed for the National Ignition Facility (NIF). This work is being performed in collaboration with Lawrence Livermore National Laboratory (LLNL). A major requirement for the indirect-drive NIF ignition target is to achieve the irradiation uniformity on the capsule surface needed for a symmetrical high-convergence implosion. Los Alamos employed an integrated modeling technique using the Lasnex radiation-hydrodynamics code to design two different targets that achieve ignition and moderate gain. Los Alamos is performing experiments on the Nova Laser at LLNL in order to validate our NIF ignition calculations

Coil-On-Plug Ignition for LOX/Methane Liquid Rocket Engines in Thermal Vacuum Environments

Science.gov (United States)

Melcher, John C.; Atwell, Matthew J.; Morehead, Robert L.; Hurlbert, Eric A.; Bugarin, Luz; Chaidez, Mariana

2017-01-01

A coil-on-plug ignition system has been developed and tested for Liquid Oxygen (LOX) / liquid methane rocket engines operating in thermal vacuum conditions. The igniters were developed and tested as part of the Integrated Cryogenic Propulsion Test Article (ICPTA), previously tested as part of the Project Morpheus test vehicle. The ICPTA uses an integrated, pressure-fed, cryogenic LOX/methane propulsion system including a reaction control system (RCS) and a main engine. The ICPTA was tested at NASA Glenn Research Center's Plum Brook Station in the Spacecraft Propulsion Research Facility (B-2) under vacuum and thermal vacuum conditions. In order to successfully demonstrate ignition reliability in the vacuum conditions and eliminate corona discharge issues, a coil-on-plug ignition system has been developed. The ICPTA uses spark-plug ignition for both the main engine igniter and the RCS. The coil-on-plug configuration eliminates the conventional high-voltage spark plug cable by combining the coil and the spark-plug into a single component. Prior to ICPTA testing at Plum Brook, component-level reaction control engine (RCE) and main engine igniter testing was conducted at NASA Johnson Space Center (JSC), which demonstrated successful hot-fire ignition using the coil-on-plug from sea-level ambient conditions down to 10(exp.-2) torr. Integrated vehicle hot-fire testing at JSC demonstrated electrical and command/data system performance. Lastly, Plum Brook testing demonstrated successful ignitions at simulated altitude conditions at 30 torr and cold thermal-vacuum conditions at 6 torr. The test campaign successfully proved that coil-on-plug technology will enable integrated LOX/methane propulsion systems in future spacecraft.

Coil-On-Plug Ignition for Oxygen/Methane Liquid Rocket Engines in Thermal-Vacuum Environments

Science.gov (United States)

Melcher, John C.; Atwell, Matthew J.; Morehead, Robert L.; Hurlbert, Eric A.; Bugarin, Luz; Chaidez, Mariana

2017-01-01

A coil-on-plug ignition system has been developed and tested for Liquid Oxygen (LOX)/liquid methane (LCH4) rocket engines operating in thermal vacuum conditions. The igniters were developed and tested as part of the Integrated Cryogenic Propulsion Test Article (ICPTA), previously tested as part of the Project Morpheus test vehicle. The ICPTA uses an integrated, pressure-fed, cryogenic LOX/LCH4 propulsion system including a reaction control system (RCS) and a main engine. The ICPTA was tested at NASA Glenn Research Center's Plum Brook Station in the Spacecraft Propulsion Research Facility (B-2) under vacuum and thermal vacuum conditions. A coil-on-plug ignition system has been developed to successfully demonstrate ignition reliability at these conditions while preventing corona discharge issues. The ICPTA uses spark plug ignition for both the main engine igniter and the RCS. The coil-on-plug configuration eliminates the conventional high-voltage spark plug cable by combining the coil and the spark plug into a single component. Prior to ICPTA testing at Plum Brook, component-level reaction control engine (RCE) and main engine igniter testing was conducted at NASA Johnson Space Center (JSC), which demonstrated successful hot-fire ignition using the coil-on-plug from sea-level ambient conditions down to 10(exp -2) torr. Integrated vehicle hot-fire testing at JSC demonstrated electrical and command/data system performance. Lastly, hot-fire testing at Plum Brook demonstrated successful ignitions at simulated altitude conditions at 30 torr and cold thermal-vacuum conditions at 6 torr. The test campaign successfully proved that coil-on-plug technology will enable integrated LOX/LCH4 propulsion systems in future spacecraft.

High-Gain Shock Ignition on the National Ignition Facility

Science.gov (United States)

Perkins, L. J.; Lafortune, K.; Bailey, D.; Lambert, M.; MacKinnon, A.; Blackfield, D.; Comley, A.; Schurtz, G.; Ribeyre, X.; Lebel, E.; Casner, A.; Craxton, R. S.; Betti, R.; McKenty, P.; Anderson, K.; Theobald, W.; Schmitt, A.; Atzeni, S.; Schiavi, A.

2010-11-01

Shock ignition offers the possibility for a near-term test of high-gain ICF on the NIF at less than 1MJ drive energy and with day-1 laser hardware. We will summarize the status of target performance simulations, delineate the critical issues and describe the R&D program to be performed in order to test the potential of a shock-ignited target on NIF. In shock ignition, compressed fuel is separately ignited by a late-time laser-driven shock and, because capsule implosion velocities are significantly lower than those required for conventional hotpot ignition, simulations indicate that fusion energy gains of 60 may be achievable at laser energies around 0.5MJ. Like fast ignition, shock ignition offers high gain but requires only a single laser with less demanding timing and focusing requirements. Conventional symmetry and stability constraints apply, thus a key immediate step towards attempting shock ignition on NIF is to demonstrate adequacy of low-mode uniformity and shock symmetry under polar drive

Pulse heating and ignition for off-centre ignited targets

International Nuclear Information System (INIS)

Mahdy, A.I.; Takabe, H.; Mima, K.

1999-01-01

An off-centre ignition model has been used to study the ignition conditions for laser targets related to the fast ignition scheme. A 2-D hydrodynamic code has been used, including alpha particle heating. The main goal of the study is the possibility of obtaining a high gain ICF target with fast ignition. In order to determine the ignition conditions, samples with various compressed core densities having different spark density-radius product (i.e. areal density) values were selected. The study was carried out in the presence of an external heating source, with a constant heating rate. A dependence of the ignition conditions on the heating rate of the external pulse is demonstrated. For a given set of ignition conditions, our simulation showed that an 11 ps pulse with 17 kJ of injected energy into the spark area was required to achieve ignition for a compressed core with a density of 200 g/cm 3 and 0.5 g/cm 2 spark areal density. It is shown that the ignition conditions are highly dependent on the heating rate of the external pulse. (author)

Electrically heated 3D-macro cellular SiC structures for ignition and combustion application

International Nuclear Information System (INIS)

Falgenhauer, Ralf; Rambacher, Patrick; Schlier, Lorenz; Volkert, Jochen; Travitzky, Nahum; Greil, Peter; Weclas, Miroslaw

2017-01-01

Highlights: • 3D-printed macro cellular SiC structure. • Directly integrated electrically heated ignition element used in combustion reactor. • Experimental investigation of the ignition process. - Abstract: The paper describes different aspects of porous combustion reactor operation especially at cold start conditions. Under cold start conditions it is necessary to increase the internal energy of the combustion reactor, to accumulate enough energy inside its solid phase and to reach at least the ignition temperature on the reactors inner surface. The most practicable method to preheat a cold porous reactor is to use its surface as a flame holder and to apply free flame combustion as a heat source for the preheating process. This paper presents a new electrically heated ignition element, which gets integrated in a three dimensional macro-cellular SiSiC reactor structure. For the development of the ignition element it was assumed, that the element is made of the same material as the combustion reactor itself and is fully integrated within the three-dimensional macro-cellular structure of the combustion reactor. Additive manufacturing like three-dimensional (3D) printing permits the production of regular SiSiC structures with constant strut thickness and a defined current flow path. To get a controlled temperature distribution on the ignition element it is necessary to control the current density distribution in the three-dimensional macro-cellular reactor structure. The ignition element used is designed to be an electrical resistance in an electric current system, converting flowing current into heat with the goal to get the highest temperature in the ignition region (glow plug). First experiments show that the ignition element integrated in a combustion reactor exhibits high dynamics and can be heated to the temperatures much above 1000 °C in a very short time (approx. 800 ms) for current of I = 150 A.

Performance evaluation of multi-stratum resources integration based on network function virtualization in software defined elastic data center optical interconnect.

Science.gov (United States)

Yang, Hui; Zhang, Jie; Ji, Yuefeng; Tian, Rui; Han, Jianrui; Lee, Young

2015-11-30

Data center interconnect with elastic optical network is a promising scenario to meet the high burstiness and high-bandwidth requirements of data center services. In our previous work, we implemented multi-stratum resilience between IP and elastic optical networks that allows to accommodate data center services. In view of this, this study extends to consider the resource integration by breaking the limit of network device, which can enhance the resource utilization. We propose a novel multi-stratum resources integration (MSRI) architecture based on network function virtualization in software defined elastic data center optical interconnect. A resource integrated mapping (RIM) scheme for MSRI is introduced in the proposed architecture. The MSRI can accommodate the data center services with resources integration when the single function or resource is relatively scarce to provision the services, and enhance globally integrated optimization of optical network and application resources. The overall feasibility and efficiency of the proposed architecture are experimentally verified on the control plane of OpenFlow-based enhanced software defined networking (eSDN) testbed. The performance of RIM scheme under heavy traffic load scenario is also quantitatively evaluated based on MSRI architecture in terms of path blocking probability, provisioning latency and resource utilization, compared with other provisioning schemes.

Electronic interconnects and devices with topological surface states and methods for fabricating same

Science.gov (United States)

Yazdani, Ali; Ong, N. Phuan; Cava, Robert J.

2016-05-03

An interconnect is disclosed with enhanced immunity of electrical conductivity to defects. The interconnect includes a material with charge carriers having topological surface states. Also disclosed is a method for fabricating such interconnects. Also disclosed is an integrated circuit including such interconnects. Also disclosed is a gated electronic device including a material with charge carriers having topological surface states.

Electronic interconnects and devices with topological surface states and methods for fabricating same

Energy Technology Data Exchange (ETDEWEB)

Yazdani, Ali; Ong, N. Phuan; Cava, Robert J.

2017-04-04

An interconnect is disclosed with enhanced immunity of electrical conductivity to defects. The interconnect includes a material with charge carriers having topological surface states. Also disclosed is a method for fabricating such interconnects. Also disclosed is an integrated circuit including such interconnects. Also disclosed is a gated electronic device including a material with charge carriers having topological surface states.

Ultra-Stretchable Interconnects for High-Density Stretchable Electronics

Directory of Open Access Journals (Sweden)

Salman Shafqat

2017-09-01

Full Text Available The exciting field of stretchable electronics (SE promises numerous novel applications, particularly in-body and medical diagnostics devices. However, future advanced SE miniature devices will require high-density, extremely stretchable interconnects with micron-scale footprints, which calls for proven standardized (complementary metal-oxide semiconductor (CMOS-type process recipes using bulk integrated circuit (IC microfabrication tools and fine-pitch photolithography patterning. Here, we address this combined challenge of microfabrication with extreme stretchability for high-density SE devices by introducing CMOS-enabled, free-standing, miniaturized interconnect structures that fully exploit their 3D kinematic freedom through an interplay of buckling, torsion, and bending to maximize stretchability. Integration with standard CMOS-type batch processing is assured by utilizing the Flex-to-Rigid (F2R post-processing technology to make the back-end-of-line interconnect structures free-standing, thus enabling the routine microfabrication of highly-stretchable interconnects. The performance and reproducibility of these free-standing structures is promising: an elastic stretch beyond 2000% and ultimate (plastic stretch beyond 3000%, with <0.3% resistance change, and >10 million cycles at 1000% stretch with <1% resistance change. This generic technology provides a new route to exciting highly-stretchable miniature devices.

Software quality assurance plan for the National Ignition Facility integrated computer control system

Energy Technology Data Exchange (ETDEWEB)

Woodruff, J.

1996-11-01

Quality achievement is the responsibility of the line organizations of the National Ignition Facility (NIF) Project. This Software Quality Assurance Plan (SQAP) applies to the activities of the Integrated Computer Control System (ICCS) organization and its subcontractors. The Plan describes the activities implemented by the ICCS section to achieve quality in the NIF Project`s controls software and implements the NIF Quality Assurance Program Plan (QAPP, NIF-95-499, L-15958-2) and the Department of Energy`s (DOE`s) Order 5700.6C. This SQAP governs the quality affecting activities associated with developing and deploying all control system software during the life cycle of the NIF Project.

Software quality assurance plan for the National Ignition Facility integrated computer control system

International Nuclear Information System (INIS)

Woodruff, J.

1996-11-01

Quality achievement is the responsibility of the line organizations of the National Ignition Facility (NIF) Project. This Software Quality Assurance Plan (SQAP) applies to the activities of the Integrated Computer Control System (ICCS) organization and its subcontractors. The Plan describes the activities implemented by the ICCS section to achieve quality in the NIF Project's controls software and implements the NIF Quality Assurance Program Plan (QAPP, NIF-95-499, L-15958-2) and the Department of Energy's (DOE's) Order 5700.6C. This SQAP governs the quality affecting activities associated with developing and deploying all control system software during the life cycle of the NIF Project

An interconnecting bus power optimization method combining interconnect wire spacing with wire ordering

International Nuclear Information System (INIS)

Zhu Zhang-Ming; Hao Bao-Tian; En Yun-Fei; Yang Yin-Tang; Li Yue-Jin

2011-01-01

On-chip interconnect buses consume tens of percents of dynamic power in a nanometer scale integrated circuit and they will consume more power with the rapid scaling down of technology size and continuously rising clock frequency, therefore it is meaningful to lower the interconnecting bus power in design. In this paper, a simple yet accurate interconnect parasitic capacitance model is presented first and then, based on this model, a novel interconnecting bus optimization method is proposed. Wire spacing is a process for spacing wires for minimum dynamic power, while wire ordering is a process that searches for wire orders that maximally enhance it. The method, i.e., combining wire spacing with wire ordering, focuses on bus dynamic power optimization with a consideration of bus performance requirements. The optimization method is verified based on various nanometer technology parameters, showing that with 50% slack of routing space, 25.71% and 32.65% of power can be saved on average by the proposed optimization method for a global bus and an intermediate bus, respectively, under a 65-nm technology node, compared with 21.78% and 27.68% of power saved on average by uniform spacing technology. The proposed method is especially suitable for computer-aided design of nanometer scale on-chip buses. (interdisciplinary physics and related areas of science and technology)

A polar-drive shock-ignition design for the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Anderson, K. S.; McKenty, P. W.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Marozas, J. A.; Skupsky, S.; Shvydky, A. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Betti, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Departments of Mechanical Engineering and Physics, University of Rochester, Rochester, New York 14627 (United States); Hohenberger, M.; Theobald, W.; Lafon, M.; Nora, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States)

2013-05-15

Shock ignition [R. Betti et al., Phys. Rev. Lett. 98, 155001 (2007)] is being pursued as a viable option to achieve ignition on the National Ignition Facility (NIF). Shock-ignition target designs use a high-intensity laser spike at the end of a low-adiabat assembly pulse to launch a spherically convergent strong shock to ignite the hot spot of an imploding capsule. A shock-ignition target design for the NIF is presented. One-dimensional simulations indicate an ignition threshold factor of 4.1 with a gain of 58. A polar-drive beam-pointing configuration for shock-ignition experiments on the NIF at 750 kJ is proposed. The capsule design is shown to be robust to the various one- and two-dimensional effects and nonuniformities anticipated on the NIF. The target is predicted to ignite with a gain of 38 when including all anticipated levels of nonuniformity and system uncertainty.

The Ignition Target for the National Ignition Facility

International Nuclear Information System (INIS)

Atherton, L J; Moses, E I; Carlisle, K; Kilkenny, J

2007-01-01

The National Ignition Facility (NIF) is a 192 beam Nd-glass laser facility presently under construction at Lawrence Livermore National Laboratory (LLNL) for performing inertial confinement fusion (ICF) and experiments studying high energy density (HED) science. When completed in 2009, NIF will be able to produce 1.8 MJ, 500 TW of ultraviolet light for target experiments that will create conditions of extreme temperatures (>10 8 K), pressures (10-GBar) and matter densities (> 100 g/cm 3 ). A detailed program called the National Ignition Campaign (NIC) has been developed to enable ignition experiments in 2010, with the goal of producing fusion ignition and burn of a deuterium-tritium (DT) fuel mixture in millimeter-scale target capsules. The first of the target experiments leading up to these ignition shots will begin in 2008. Targets for the National Ignition Campaign are both complex and precise, and are extraordinarily demanding in materials fabrication, machining, assembly, cryogenics and characterization. An overview of the campaign for ignition will be presented, along with technologies for target fabrication, assembly and metrology and advances in growth and x-ray imaging of DT ice layers. The sum of these efforts represents a quantum leap in target precision, characterization, manufacturing rate and flexibility over current state-of-the-art

Processing and Prolonged 500 C Testing of 4H-SiC JFET Integrated Circuits with Two Levels of Metal Interconnect

Science.gov (United States)

Spry, David J.; Neudeck, Philip G.; Chen, Liangyu; Lukco, Dorothy; Chang, Carl W.; Beheim, Glenn M.; Krasowski, Michael J.; Prokop, Norman F.

2015-01-01

Complex integrated circuit (IC) chips rely on more than one level of interconnect metallization for routing of electrical power and signals. This work reports the processing and testing of 4H-SiC junction field effect transistor (JFET) prototype IC's with two levels of metal interconnect capable of prolonged operation at 500 C. Packaged functional circuits including 3- and 11-stage ring oscillators, a 4-bit digital to analog converter, and a 4-bit address decoder and random access memory cell have been demonstrated at 500 C. A 3-stage oscillator functioned for over 3000 hours at 500 C in air ambient. Improved reproducibility remains to be accomplished.

Shock Tube Ignition Delay Data Affected by Localized Ignition Phenomena

KAUST Repository

Javed, Tamour

2016-12-29

Shock tubes have conventionally been used for measuring high-temperature ignition delay times ~ O(1 ms). In the last decade or so, the operating regime of shock tubes has been extended to lower temperatures by accessing longer observation times. Such measurements may potentially be affected by some non-ideal phenomena. The purpose of this work is to measure long ignition delay times for fuels exhibiting negative temperature coefficient (NTC) and to assess the impact of shock tube non-idealities on ignition delay data. Ignition delay times of n-heptane and n-hexane were measured over the temperature range of 650 – 1250 K and pressures near 1.5 atm. Driver gas tailoring and long length of shock tube driver section were utilized to measure ignition delay times as long as 32 ms. Measured ignition delay times agree with chemical kinetic models at high (> 1100 K) and low (< 700 K) temperatures. In the intermediate temperature range (700 – 1100 K), however, significant discrepancies are observed between the measurements and homogeneous ignition delay simulations. It is postulated, based on experimental observations, that localized ignition kernels could affect the ignition delay times at the intermediate temperatures, which lead to compression (and heating) of the bulk gas and result in expediting the overall ignition event. The postulate is validated through simple representative computational fluid dynamic simulations of post-shock gas mixtures which exhibit ignition advancement via a hot spot. The results of the current work show that ignition delay times measured by shock tubes may be affected by non-ideal phenomena for certain conditions of temperature, pressure and fuel reactivity. Care must, therefore, be exercised in using such data for chemical kinetic model development and validation.

Safety Implementation of Hydrogen Igniters and Recombiners for Nuclear Power Plant Severe Accident Management

Institute of Scientific and Technical Information of China (English)

XIAO Jianjun; ZHOU Zhiwei; JING Xingqing

2006-01-01

Hydrogen combustion in a nuclear power plant containment building may threaten the integrity of the containment. Hydrogen recombiners and igniters are two methods to reduce hydrogen levels in containment buildings during severe accidents. The purpose of this paper is to evaluate the safety implementation of hydrogen igniters and recombiners. This paper analyzes the risk of deliberate hydrogen ignition and investigates three mitigation measures using igniters only, hydrogen recombiners only or a combination of recombiners and igniters. The results indicate that steam can effectively control the hydrogen flame acceleration and the deflagration-to-detonation transition.

Electro-optic techniques for VLSI interconnect

Science.gov (United States)

Neff, J. A.

1985-03-01

A major limitation to achieving significant speed increases in very large scale integration (VLSI) lies in the metallic interconnects. They are costly not only from the charge transport standpoint but also from capacitive loading effects. The Defense Advanced Research Projects Agency, in pursuit of the fifth generation supercomputer, is investigating alternatives to the VLSI metallic interconnects, especially the use of optical techniques to transport the information either inter or intrachip. As the on chip performance of VLSI continues to improve via the scale down of the logic elements, the problems associated with transferring data off and onto the chip become more severe. The use of optical carriers to transfer the information within the computer is very appealing from several viewpoints. Besides the potential for gigabit propagation rates, the conversion from electronics to optics conveniently provides a decoupling of the various circuits from one another. Significant gains will also be realized in reducing cross talk between the metallic routings, and the interconnects need no longer be constrained to the plane of a thin film on the VLSI chip. In addition, optics can offer an increased programming flexibility for restructuring the interconnect network.

Report on electricity interconnection management and use. June 2008

International Nuclear Information System (INIS)

2008-06-01

Apart from some concrete advances in interconnection management, the most striking event of 2007 has to be the emergence of a consensus at European level on the general principles of the target mechanisms for interconnection management. Three major projects currently undergoing development by the TSOs and the exchanges - the setting up of a single auction platform for allocating long- and medium-term products and of 'flow-based' market coupling in the Central-West region (Belgium, Luxemburg, the Netherlands, Germany, France), and in the France-UK-Ireland region, the introduction of reciprocal balancing exchanges on the France-England interconnection - should lay the foundations for the future management of congestion on interconnections in Europe. The completion of these projects, planned for the end of 2008 for the single auction platform project in the Central-West region and for mid-2009 for the other two, will be an important turning point in the construction of the European electricity market. This will be one of the successes of the Regional Initiatives process launched by ERGEG just over two years ago. However, this should not hide the fact that the regulators have experienced many difficulties during the regional integration of the markets and that the market operators have the general impression that this process could progress much more quickly. These difficulties and this relative slowness are mainly explained by: - a lack of consensus on the target market design the national markets would gradually tend towards, - a lack of harmonisation of the powers and competencies of the regulators when it comes to cross-border trades, the immediate consequence of which is a lack of incentives for TSOs to accelerate market integration. Several sizeable challenges await all the stakeholders over the coming months and years if market integration is to be a success: - How can the 'third legislative package' give all the necessary competencies

Direct-drive–ignition designs with mid-Z ablators

Energy Technology Data Exchange (ETDEWEB)

Lafon, M.; Betti, R. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Anderson, K. S.; Collins, T. J. B.; Epstein, R.; McKenty, P. W.; Myatt, J. F.; Shvydky, A.; Skupsky, S. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)

2015-03-15

Achieving thermonuclear ignition using direct laser illumination relies on the capability to accelerate spherical shells to high implosion velocities while maintaining shell integrity. Ablator materials of moderate atomic number Z reduce the detrimental effects of laser–plasma instabilities in direct-drive implosions. To validate the physics of moderate-Z ablator materials for ignition target designs on the National Ignition Facility (NIF), hydro-equivalent targets are designed using pure plastic (CH), high-density carbon, and glass (SiO{sub 2}) ablators. The hydrodynamic stability of these targets is investigated through two-dimensional (2D) single-mode and multimode simulations. The overall stability of these targets to laser-imprint perturbations and low-mode asymmetries makes it possible to design high-gain targets. Designs using polar-drive illumination are developed within the NIF laser system specifications. Mid-Z ablator targets are an attractive candidate for direct-drive ignition since they present better overall performance than plastic ablator targets through reduced laser–plasma instabilities and a similar hydrodynamic stability.

Ignition and Inertial Confinement Fusion at The National Ignition Facility

International Nuclear Information System (INIS)

Moses, E.

2009-01-01

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and for studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF is now conducting experiments to commission the laser drive, the hohlraum and the capsule and to develop the infrastructure needed to begin the first ignition experiments in FY 2010. Demonstration of ignition and thermonuclear burn in the laboratory is a major NIF goal. NIF will achieve this by concentrating the energy from the 192 beams into a mm 3 -sized target and igniting a deuterium-tritium mix, liberating more energy than is required to initiate the fusion reaction. NIF's ignition program is a national effort managed via the National Ignition Campaign (NIC). The NIC has two major goals: execution of DT ignition experiments starting in FY2010 with the goal of demonstrating ignition and a reliable, repeatable ignition platform by the conclusion of the NIC at the end of FY2012. The NIC will also develop the infrastructure and the processes required to operate NIF as a national user facility. The achievement of ignition at NIF will demonstrate the scientific feasibility of ICF and focus worldwide attention on laser fusion as a viable energy option. A laser fusion-based energy concept that builds on NIF, known as LIFE (Laser Inertial Fusion Energy), is currently under development. LIFE is inherently safe and can provide a global carbon-free energy generation solution in the 21st century. This paper describes recent progress on NIF, NIC, and the LIFE concept.

Ignition of a combustible half space

Science.gov (United States)

Olmstead, W. E.

1983-01-01

A half space of combustible material is subjected to an arbitrary energy flux at the boundary where convection heat loss is also allowed. An asymptotic analysis of the temperature growth reveals two conditions necessary for ignition to occur. Cases of both large and order unity Lewis number are shown to lead to a nonlinear integral equation governing the thermal runaway. Some global and asymptotic properties of the integral equation are obtained.

Simple and reusable fibre-to-chip interconnect with adjustable coupling eficiency

NARCIS (Netherlands)

Heideman, Rene; Lambeck, Paul; Parriaux, Olivier M.; Kley, Ernst-Bernhard

1997-01-01

A simple, efficient and reusable fiber-to-chip interconnect is presented. The interconnect is based on a V-groove (wet- chemically etched) in silicon, combined with a loose-mode Si3N4-channel waveguide. The loose-mode waveguide is adiabatically tapered to the integrated optical (sensor) circuitry.

Analysis of Hydrogen Control Strategy Using Igniter during Severe Accident

International Nuclear Information System (INIS)

Lee, Sung Bok; Kim, Hyeong Taek; Lee, Keo Hyoung

2008-01-01

The Severe Accident Management Guidelines (SAMGs) for the operating pressurized water reactor (PWR) have been completed within 2006. Among the SAMG strategies, mitigation-07 is the most important strategy for managing a severe accident of a PWR in order to reduce containment hydrogen. The fastest way to reduce the containment hydrogen concentration is to intentionally ignite the hydrogen. For this strategy, igniters exist in Optimized Power Reactor 1000 (OPR 1000) to burn hydrogen for a severe accident. For using the igniters during a severe accident, the adverse effects such as the explosion of the hydrogen mixture should be considered for containment integrity. However, an applicable discrimination method to activate the igniters does not exist, so that the hydrogen control strategy using the igniters cannot be chosen during a severe accident. Thus, this study focused on suggesting an applicable discrimination method to carry out the strategy of using the igniters. In this study, the specific plant used for this analysis is Ulchin Unit 5 and 6, OPR 1000 plant, in Korea

Next generation space interconnect research and development in space communications

Science.gov (United States)

Collier, Charles Patrick

2017-11-01

Interconnect or "bus" is one of the critical technologies in design of spacecraft avionics systems that dictates its architecture and complexity. MIL-STD-1553B has long been used as the avionics backbone technology. As avionics systems become more and more capable and complex, however, limitations of MIL-STD-1553B such as insufficient 1 Mbps bandwidth and separability have forced current avionics architects and designers to use combination of different interconnect technologies in order to meet various requirements: CompactPCI is used for backplane interconnect; LVDS or RS422 is used for low and high-speed direct point-to-point interconnect; and some proprietary interconnect standards are designed for custom interfaces. This results in a very complicated system that consumes significant spacecraft mass and power and requires extensive resources in design, integration and testing of spacecraft systems.

Recent progress in ignition fusion research on the National Ignition Facility

International Nuclear Information System (INIS)

Leeper, Ramon J.

2011-01-01

This paper will review the ignition fusion research program that is currently being carried out on the National Ignition Facility (NIF) located at Lawrence Livermore National Laboratory. This work is being conducted under the auspices of the National Ignition Campaign (NIC) that is a broad collaboration of national laboratories and universities that together have developed a detailed research plan whose goal is ignition in the laboratory. The paper will begin with a description of the NIF facility and associated experimental facilities. The paper will then focus on the ignition target and hohlraum designs that will be tested in the first ignition attempts on NIF. The next topic to be introduced will be a description of the diagnostic suite that has been developed for the initial ignition experiments on NIF. The paper will then describe the experimental results that were obtained in experiments conducted during the fall of 2009 on NIF. Finally, the paper will end with a description of the detailed experimental plans that have been developed for the first ignition campaign that will begin later this year. (author)

New High Voltage Interconnections with Islands in the Mediterranean Sea: Malta and Sicily. Analysis of the Effects on Renewable Energy Sources Integration and Benefits for the Electricity Market

Directory of Open Access Journals (Sweden)

Mariano Giuseppe Ippolito

2018-04-01

Full Text Available The present paper shows the benefits coming from the operation of the recent electrical high voltage (HV interconnections between Sicily, Malta and mainland Italy. These new interconnections allow zonal prices of electricity considerably lower than in the past, ensuring greater flexibility to the system and a better integration of Renewable Energy Sources (RES. After briefly illustrating the two high-voltage electrical systems (Sicily and Malta, and having provided a description of the interconnection cable with Malta and its protection devices, the authors hypothesized two modes of operation (Sicily-Malta system islanded or interconnected to the rest of Europe. For the first case (islanded some simulations are performed through the use of an electric network model realized in the Neplan® environment, and for the second case an analysis of one year real data was made. The results of the simulation, thanks to the use of a power flow tracing method, show that this new interconnection between the two islands (Sicily and Malta allows an important improvement in the integration and dispatching of the power generated by RES of the Sicilian territory, better operation of traditional Sicilian generation units, lower electricity zonal prices and a significant reduction in emissions from obsolete fuel oil thermal units located in Malta.

One-step fabrication of microfluidic chips with in-plane, adhesive-free interconnections

International Nuclear Information System (INIS)

Sabourin, D; Dufva, M; Jensen, T; Kutter, J; Snakenborg, D

2010-01-01

A simple method for creating interconnections to a common microfluidic device material, poly(methyl methacrylate) (PMMA), is presented. A press-fit interconnection is created between oversized, deformable tubing and complementary, undersized semi-circular ports fabricated into PMMA bonding surfaces by direct micromilling. Upon UV-assisted bonding the tubing is trapped in the ports of the PMMA chip and forms an integrated, in-plane and adhesive-free interconnection. The interconnections support the average pressure of 6.1 bar and can be made with small dead volumes. A comparison is made to a similar interconnection approach which uses tubing to act as a gasket between a needle and port on the microfluidic chip. (technical note)

Physical Improvements in Exciter/Igniter Units, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The proposed Phase 2 project consists of the physical integration of our Phase 1 small, compact exciter with a "flight like" igniter or spark plug capable of...

Two-dimensional optoelectronic interconnect-processor and its operational bit error rate

Science.gov (United States)

Liu, J. Jiang; Gollsneider, Brian; Chang, Wayne H.; Carhart, Gary W.; Vorontsov, Mikhail A.; Simonis, George J.; Shoop, Barry L.

2004-10-01

Two-dimensional (2-D) multi-channel 8x8 optical interconnect and processor system were designed and developed using complementary metal-oxide-semiconductor (CMOS) driven 850-nm vertical-cavity surface-emitting laser (VCSEL) arrays and the photodetector (PD) arrays with corresponding wavelengths. We performed operation and bit-error-rate (BER) analysis on this free-space integrated 8x8 VCSEL optical interconnects driven by silicon-on-sapphire (SOS) circuits. Pseudo-random bit stream (PRBS) data sequence was used in operation of the interconnects. Eye diagrams were measured from individual channels and analyzed using a digital oscilloscope at data rates from 155 Mb/s to 1.5 Gb/s. Using a statistical model of Gaussian distribution for the random noise in the transmission, we developed a method to compute the BER instantaneously with the digital eye-diagrams. Direct measurements on this interconnects were also taken on a standard BER tester for verification. We found that the results of two methods were in the same order and within 50% accuracy. The integrated interconnects were investigated in an optoelectronic processing architecture of digital halftoning image processor. Error diffusion networks implemented by the inherently parallel nature of photonics promise to provide high quality digital halftoned images.

Essays on optimal capacity and optimal regulation of interconnection infrastructures

Science.gov (United States)

Boffa, Federico

The integration between geographically differentiated markets or between vertically related industries generate effects on welfare that depend on the structure of the underlying markets. My thesis investigates the impact of geographical interconnection on welfare, and illustrates welfare-enhancing modes of regulation of vertically integrated industries and of geographically integrated markets. The first chapter analyzes the effects of interconnection between two formerly fully-separated markets under the assumptions that producers in the two markets are capacity-constrained, and tacitly collude whenever it is rational for them to do so. I find that there exists a set of assumptions under which interconnection brings about greater collusion, hence it reduces overall welfare. The second chapter analyzes the optimal interconnection capacity allocation mechanism for a benevolent electricity regulator when generation is not competitive. The regulator's intervention should not only ensure that interconnection capacity is efficiently allocated to the most efficient firms, but it should also induce a higher welfare in the upstream generation market. In a two-node setting, with one firm per node, I show that the regulatory intervention becomes more effective as the cost asymmetries between the two firms become more pronounced. The third chapter illustrates a regulation mechanism for vertically related industries. Ownership shares of the upstream industry (that displays economies of scale) are allocated to the downstream (competitive) firms in proportion to their shares in the final goods market. I show that the mechanism combines the benefits of vertical integration with those of vertical separation. The advantages of vertical integration consist in avoiding double marginalization, and in internalizing the reduction in average cost resulting from the upstream increase in output; on the other hand, vertical separation allows to preserve the competitiveness of the downstream

Interconnection Guidelines

Science.gov (United States)

The Interconnection Guidelines provide general guidance on the steps involved with connecting biogas recovery systems to the utility electrical power grid. Interconnection best practices including time and cost estimates are discussed.

Interconnectivity: Benefits and Challenges

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-09-15

Access to affordable and reliable electricity supplies is a basic prerequisite for economic and social development, prosperity, health, education and all other aspects of modern society. Electricity can be generated both near and far from the consumption areas as transmission lines, grid interconnections and distribution systems can transport it to the final consumer. In the vast majority of countries, the electricity sector used to be owned and run by the state. The wave of privatisation and market introduction in a number of countries and regions which started in the late 1980's has in many cases involved unbundling of generation from transmission and distribution (T and D). This has nearly everywhere exposed transmission bottlenecks limiting the development of well-functioning markets. Transmission on average accounts for about 10-15% of total final kWh cost paid by the end-user but it is becoming a key issue for effective operation of liberalised markets and for their further development. An integrated and adequate transmission infrastructure is of utmost importance for ensuring the delivery of the most competitively priced electricity, including externalities, to customers, both near and far from the power generating facilities. In this report, the role of interconnectivity in the development of energy systems is examined with the associated socio-economic, environmental, financial and regulatory aspects that must be taken into account for successful interconnection projects.

Innovative ICF scheme-impact fast ignition

International Nuclear Information System (INIS)

Murakami, M.; Nagatomo, H.; Sakaiya, T.; Karasik, M.; Gardner, J.; Bates, J.

2007-01-01

A totally new ignition scheme for ICF, impact fast ignition (IFI), is proposed [1], in which the compressed DT main fuel is to be ignited by impact collision of another fraction of separately imploded DT fuel, which is accelerated in the hollow conical target. Two-dimensional hydrodynamic simulation results in full geometry are presented, in which some key physical parameters for the impact shell dynamics such as 10 8 cm/s of the implosion velocity, 200- 300 g/cm 3 of the compressed density, and the converted temperature beyond 5 keV are demonstrated. As the first step toward the proof-of-principle of IFI, we have conducted preliminary experiments under the operation of GEKKO XII/HYPER laser system to achieve a hyper-velocity of the order of 108 cm/s. As a result we have observed a highest velocity, 6.5 x 10 7 cm/s, ever achieved. Furthermore, we have also done the first integrated experiments using the target and observed substantial amount of neutron yields. Reference: [1] M. Murakami and Nagatomo, Nucl. Instrum. Meth. Phys. Res. A 544(2005) 67

Bottom-up approach for carbon nanotube interconnects

International Nuclear Information System (INIS)

Li Jun; Ye Qi; Cassell, Alan; Ng, Hou Tee; Stevens, Ramsey; Han Jie; Meyyappan, M.

2003-01-01

We report a bottom-up approach to integrate multiwalled carbon nanotubes (MWNTs) into multilevel interconnects in silicon integrated-circuit manufacturing. MWNTs are grown vertically from patterned catalyst spots using plasma-enhanced chemical vapor deposition. We demonstrate the capability to grow aligned structures ranging from a single tube to forest-like arrays at desired locations. SiO 2 is deposited to encapsulate each nanotube and the substrate, followed by a mechanical polishing process for planarization. MWNTs retain their integrity and demonstrate electrical properties consistent with their original structure

Examination of Critical Length Effect in Copper Interconnects With Oxide and Low-k Dielectrics

International Nuclear Information System (INIS)

Thrasher, Stacye; Gall, Martin; Justison, Patrick; Hernandez, Richard; Kawasaki, Hisao; Capasso, Cristiano; Nguyen, Timothy

2004-01-01

As technology moves toward faster microelectronic devices with smaller feature sizes, copper is replacing aluminum-copper alloy and low-k dielectric is replacing oxide as the materials of choice for advanced interconnect integrations. Copper not only brings to the table the advantage of lower resistivity, but also exhibits better electromigration performance when compared to Al(Cu). Low-k dielectric materials are advantageous because they reduce power consumption and improve signal delay. Due to these advantages, the industry trend is moving towards integrating copper and low-k dielectric for high performance interconnects. The purpose of this study is to evaluate the critical length effect in single-inlaid copper interconnects and determine the critical product (jl)c, for a variety of integrations, examining the effect of ILD (oxide vs. low-k), geometry, and stress temperature

Transurban interconnectivities

DEFF Research Database (Denmark)

Jørgensen, Claus Møller

2012-01-01

This essay discusses the interpretation of the revolutionary situations of 1848 in light of recent debates on interconnectivity in history. The concept of transurban interconnectivities is proposed as the most precise concept to capture the nature of interconnectivity in 1848. It is argued....... It is argued that circulating political communication accounts for similarities with respect to political agenda, organisational form and political repertoire evident in urban settings across Europe. This argument is supported by a series of examples of local organisation and local appropriations of liberalism...

Dual coil ignition system

Energy Technology Data Exchange (ETDEWEB)

Huberts, Garlan J.; Qu, Qiuping; Czekala, Michael Damian

2017-03-28

A dual coil ignition system is provided. The dual coil ignition system includes a first inductive ignition coil including a first primary winding and a first secondary winding, and a second inductive ignition coil including a second primary winding and a second secondary winding, the second secondary winding connected in series to the first secondary winding. The dual coil ignition system further includes a diode network including a first diode and a second diode connected between the first secondary winding and the second secondary winding.

An RLC interconnect analyzable crosstalk model considering self-heating effect

International Nuclear Information System (INIS)

Zhu Zhang-Ming; Liu Shu-Bin

2012-01-01

According to the thermal profile of actual multilevel interconnects, in this paper we propose a temperature distribution model of multilevel interconnects and derive an analytical crosstalk model for the distributed resistance—inductance—capacitance (RLC) interconnect considering effect of thermal profile. According to the 65-nm complementary metal—oxide semiconductor (CMOS) process, we compare the proposed RLC analytical crosstalk model with the Hspice simulation results for different interconnect coupling conditions and the absolute error is within 6.5%. The computed results of the proposed analytical crosstalk model show that RCL crosstalk decreases with the increase of current density and increases with the increase of insulator thickness. This analytical crosstalk model can be applied to the electronic design automation (EDA) and the design optimization for nanometer CMOS integrated circuits. (interdisciplinary physics and related areas of science and technology)

Ignition delay times of Gasoline Distillation Cuts measured with Ignition Quality Tester

KAUST Repository

Naser, Nimal

2017-04-21

Tailoring fuel properties to maximize the efficiency of internal combustion engines is a way towards achieving cleaner combustion systems. In this work, the ignition properties of various gasoline fuel distillation cuts are analyzed to better understand fuel properties of the full boiling range fuel. An advanced distillation column (ADC) provides a more realistic representation of volatility characteristics, which can be modeled using equilibrium thermodynamic methods. The temperature reported is that of the liquid, as opposed to the vapor temperature in conventional ASTM D86 distillation standard. Various FACE (fuels for advanced combustion engines) gasolines were distilled and various cuts were obtained. The separated fractions were then tested in an ignition quality tester (IQT) to see the effect of chemical composition of different fractions on their ignition delay time. Fuels with lower aromatic content showed decreasing ignition delay time with increasing boiling point (i.e., molecular weight). However, fuels with higher aromatic content showed an initial decrease in ignition delay time with increasing boiling point, followed by drastic increase in ignition delay time due to fractions containing aromatics. This study also provides an understanding on contribution of different fractions to the ignition delay time of the fuel, which provides insights into fuel stratification utilized in gasoline compression ignition (GCI) engines to tailor heat release rates.

Dynamic analysis of solid propellant grains subjected to ignition pressurization loading

Science.gov (United States)

Chyuan, Shiang-Woei

2003-11-01

Traditionally, the transient analysis of solid propellant grains subjected to ignition pressurization loading was not considered, and quasi-elastic-static analysis was widely adopted for structural integrity because the analytical task gets simplified. But it does not mean that the dynamic effect is not useful and could be neglected arbitrarily, and this effect usually plays a very important role for some critical design. In order to simulate the dynamic response for solid rocket motor, a transient finite element model, accompanied by concepts of time-temperature shift principle, reduced integration and thermorheologically simple material assumption, was used. For studying the dynamic response, diverse ignition pressurization loading cases were used and investigated in the present paper. Results show that the dynamic effect is important for structural integrity of solid propellant grains under ignition pressurization loading. Comparing the effective stress of transient analysis and of quasi-elastic-static analysis, one can see that there is an obvious difference between them because of the dynamic effect. From the work of quasi-elastic-static and transient analyses, the dynamic analysis highlighted several areas of interest and a more accurate and reasonable result could be obtained for the engineer.

Welfare and competition effects of electricity interconnection between Ireland and Great Britain

International Nuclear Information System (INIS)

Malaguzzi Valeri, Laura

2009-01-01

This study analyzes the effects of additional interconnection on welfare and competition in the Irish electricity market. I simulate the wholesale electricity markets of the island of Ireland and Great Britain for 2005. I find that in order for the two markets to be integrated in 2005, additional interconnection would have to be large. The amount of interconnection decreases for high costs of carbon, since this causes the markets to become more similar. This suggests that in the absence of strategic behavior of firms, most of the gains from trade derive not from differences in size between countries, but from technology differences and are strongly influenced by fuel and carbon costs. Social welfare increases with interconnection, although at a decreasing rate. As the amount of interconnection increases, there are also positive effects on competition in Ireland, the less competitive of the two markets. Finally, it is unlikely that private investors will pay for the optimal amount of interconnection since their returns are significantly smaller than the total social benefit of interconnection. (author)

IC layout adjustment method and tool for improving dielectric reliability at interconnects

Energy Technology Data Exchange (ETDEWEB)

Kahng, Andrew B.; Chan, Tuck Boon

2018-03-20

Method for adjusting a layout used in making an integrated circuit includes one or more interconnects in the layout that are susceptible to dielectric breakdown are selected. One or more selected interconnects are adjusted to increase via to wire spacing with respect to at least one via and one wire of the one or more selected interconnects. Preferably, the selecting analyzes signal patterns of interconnects, and estimates the stress ratio based on state probability of routed signal nets in the layout. An annotated layout is provided that describes distances by which one or more via or wire segment edges are to be shifted. Adjustments can include thinning and shifting of wire segments, and rotation of vias.

Interconnection blocks: a method for providing reusable, rapid, multiple, aligned and planar microfluidic interconnections

International Nuclear Information System (INIS)

Sabourin, D; Snakenborg, D; Dufva, M

2009-01-01

In this paper a method is presented for creating 'interconnection blocks' that are re-usable and provide multiple, aligned and planar microfluidic interconnections. Interconnection blocks made from polydimethylsiloxane allow rapid testing of microfluidic chips and unobstructed microfluidic observation. The interconnection block method is scalable, flexible and supports high interconnection density. The average pressure limit of the interconnection block was near 5.5 bar and all individual results were well above the 2 bar threshold considered applicable to most microfluidic applications

Ignition of hydrocarbon-air supersonic flow by volumetric ionization

Science.gov (United States)

Goldfeld, Marat A.; Pozdnyakov, George A.

2015-11-01

The paper describes the results of the electron-beam initiation of the combustion in the mixtures of hydrogen, natural gas or kerosene vapors with air. Electron beam characteristics were studied in closed volume with immobile gas. The researches included definition of an integrated current of an electronic beam, distribution of a current density and an estimation of average energy of electrons. Possibility of fuel mixtures ignition by means of this approach in the combustor at high velocity at the entrance was demonstrated. Experiments were carried out at Mach numbers of 4 and 5. Process of ignition and combustion under electron beam action was researched. It was revealed that ignition of mixture occurs after completion of electron gun operation. Data obtained have confirmed effectiveness of electron beam application for ignition of hydrogen and natural gas. The numerical simulation of the combustion of mixture in channel was carried out by means of ANSYS CFD 12.0 instrumentation on the basis of Reynolds averaged Navier-Stokes equation using SST/k-ω turbulence model. For combustion modeling, a detailed kinetic scheme with 38 reactions of 8 species was implemented taking into account finite rate chemistry. Computations have shown that the developed model allow to predict ignition of a mixture and flame propagation even at low flow temperatures.

Knock Prediction Using a Simple Model for Ignition Delay

KAUST Repository

Kalghatgi, Gautam

2016-04-05

An earlier paper has shown the ability to predict the phasing of knock onset in a gasoline PFI engine using a simple ignition delay equation for an appropriate surrogate fuel made up of toluene and PRF (TPRF). The applicability of this approach is confirmed in this paper in a different engine using five different fuels of differing RON, sensitivity, and composition - including ethanol blends. An Arrhenius type equation with a pressure correction for ignition delay can be found from interpolation of previously published data for any gasoline if its RON and sensitivity are known. Then, if the pressure and temperature in the unburned gas can be estimated or measured, the Livengood-Wu integral can be estimated as a function of crank angle to predict the occurrence of knock. Experiments in a single cylinder DISI engine over a wide operating range confirm that this simple approach can predict knock very accurately. The data presented should enable engineers to study knock or other auto-ignition phenomena e.g. in premixed compression ignition (PCI) engines without explicit chemical kinetic calculations. © Copyright 2016 SAE International.

The Development of an IMU Integrated Clothes for Postural Monitoring Using Conductive Yarn and Interconnecting Technology.

Science.gov (United States)

Kang, Sung-Won; Choi, Hyeob; Park, Hyung-Il; Choi, Byoung-Gun; Im, Hyobin; Shin, Dongjun; Jung, Young-Giu; Lee, Jun-Young; Park, Hong-Won; Park, Sukyung; Roh, Jung-Sim

2017-11-07

Spinal disease is a common yet important condition that occurs because of inappropriate posture. Prevention could be achieved by continuous posture monitoring, but most measurement systems cannot be used in daily life due to factors such as burdensome wires and large sensing modules. To improve upon these weaknesses, we developed comfortable "smart wear" for posture measurement using conductive yarn for circuit patterning and a flexible printed circuit board (FPCB) for interconnections. The conductive yarn was made by twisting polyester yarn and metal filaments, and the resistance per unit length was about 0.05 Ω/cm. An embroidered circuit was made using the conductive yarn, which showed increased yield strength and uniform electrical resistance per unit length. Circuit networks of sensors and FPCBs for interconnection were integrated into clothes using a computer numerical control (CNC) embroidery process. The system was calibrated and verified by comparing the values measured by the smart wear with those measured by a motion capture camera system. Six subjects performed fixed movements and free computer work, and, with this system, we were able to measure the anterior/posterior direction tilt angle with an error of less than 4°. The smart wear does not have excessive wires, and its structure will be optimized for better posture estimation in a later study.

Stability of Ignition Transients

OpenAIRE

V.E. Zarko

1991-01-01

The problem of ignition stability arises in the case of the action of intense external heat stimuli when, resulting from the cut-off of solid substance heating, momentary ignition is followed by extinction. Physical pattern of solid propellant ignition is considered and ignition criteria available in the literature are discussed. It is shown that the above mentioned problem amounts to transient burning at a given arbitrary temperature distribution in the condensed phase. A brief survey...

Laser-plasma interaction physics for shock ignition

Directory of Open Access Journals (Sweden)

Goyon C.

2013-11-01

Full Text Available In the shock ignition scheme, the ICF target is first compressed with a long (nanosecond pulse before creating a convergent shock with a short (∼100 ps pulse to ignite thermonuclear reactions. This short pulse is typically (∼2.1015–1016 W/cm2 above LPI (Laser Plasma Instabilities thresholds. The plasma is in a regime where the electron temperature is expected to be very high (2–4 keV and the laser coupling to the plasma is not well understood. Emulating LPI in the corona requires large and hot plasmas produced by high-energy lasers. We conducted experiments on the LIL (Ligne d'Integration Laser, 10 kJ at 3ω and the LULI2000 (0.4 kJ at 2ω facilities, to approach these conditions and study absorption and LPI produced by a high intensity beam in preformed plasmas. After introducing the main risks associated with the short pulse propagation, we present the latest experiment we conducted on LPI in relevant conditions for shock ignition.

Ignition probabilities for Compact Ignition Tokamak designs

International Nuclear Information System (INIS)

Stotler, D.P.; Goldston, R.J.

1989-09-01

A global power balance code employing Monte Carlo techniques had been developed to study the ''probability of ignition'' and has been applied to several different configurations of the Compact Ignition Tokamak (CIT). Probability distributions for the critical physics parameters in the code were estimated using existing experimental data. This included a statistical evaluation of the uncertainty in extrapolating the energy confinement time. A substantial probability of ignition is predicted for CIT if peaked density profiles can be achieved or if one of the two higher plasma current configurations is employed. In other cases, values of the energy multiplication factor Q of order 10 are generally obtained. The Ignitor-U and ARIES designs are also examined briefly. Comparisons of our empirically based confinement assumptions with two theory-based transport models yield conflicting results. 41 refs., 11 figs

Antiknock quality and ignition kinetics of 2-phenylethanol, a novel lignocellulosic octane booster

KAUST Repository

Shankar, Vijai

2016-06-28

High-octane quality fuels are important for increasing spark ignition engine efficiency, but their production comes at a substantial economic and environmental cost. The possibility of producing high anti-knock quality gasoline by blending high-octane bio-derived components with low octane naphtha streams is attractive. 2-phenyl ethanol (2-PE), is one such potential candidate that can be derived from lignin, a biomass component made of interconnected aromatic groups. We first ascertained the blending anti-knock quality of 2-PE by studying the effect of spark advancement on knock for various blends 2-PE, toluene, and ethanol with naphtha in a cooperative fuels research engine. The blending octane quality of 2-PE indicated an anti-knock behavior similar or slightly greater than that of toluene, and ethylbenzene, which could be attributed to either chemical kinetics or charge cooling effects. To isolate chemical kinetic effects, a model for 2-PE auto-ignition was developed and validated using ignition delay times measured in a high-pressure shock tube. Simulated ignition delay times of 2-PE were also compared to those of traditional high-octane gasoline blending components to show that the gas phase reactivity of 2-PE is lower than ethanol, and comparable to toluene, and ethylbenzene at RON, and MON relevant conditions. The gas-phase reactivity of 2-PE is largely controlled by its aromatic ring, while the effect of the hydroxyl group is minimal. The higher blending octane quality of 2-PE compared to toluene, and ethylbenzene can be attributed primarily to the effect of the hydroxyl group on increasing heat of vaporization. © 2016 The Combustion Institute.

Interconnection, Integration, and Interactive Impact Analysis of Microgrids and Distribution Systems

Energy Technology Data Exchange (ETDEWEB)

Kang, Ning [Argonne National Lab. (ANL), Argonne, IL (United States); Wang, Jianhui [Argonne National Lab. (ANL), Argonne, IL (United States); Singh, Ravindra [Argonne National Lab. (ANL), Argonne, IL (United States); Lu, Xiaonan [Argonne National Lab. (ANL), Argonne, IL (United States)

2017-01-01

Distribution management systems (DMSs) are increasingly used by distribution system operators (DSOs) to manage the distribution grid and to monitor the status of both power imported from the transmission grid and power generated locally by a distributed energy resource (DER), to ensure that power flows and voltages along the feeders are maintained within designed limits and that appropriate measures are taken to guarantee service continuity and energy security. When microgrids are deployed and interconnected to the distribution grids, they will have an impact on the operation of the distribution grid. The challenge is to design this interconnection in such a way that it enhances the reliability and security of the distribution grid and the loads embedded in the microgrid, while providing economic benefits to all stakeholders, including the microgrid owner and operator and the distribution system operator.

Hot Surface Ignition

OpenAIRE

Tursyn, Yerbatyr; Goyal, Vikrant; Benhidjeb-Carayon, Alicia; Simmons, Richard; Meyer, Scott; Gore, Jay P.

2015-01-01

Undesirable hot surface ignition of flammable liquids is one of the hazards in ground and air transportation vehicles, which primarily occurs in the engine compartment. In order to evaluate the safety and sustainability of candidate replacement fuels with respect to hot surface ignition, a baseline low lead fuel (Avgas 100 LL) and four experimental unleaded aviation fuels recommended for reciprocating aviation engines were considered. In addition, hot surface ignition properties of the gas tu...

Multilevel Dual Damascene copper interconnections

Science.gov (United States)

Lakshminarayanan, S.

Copper has been acknowledged as the interconnect material for future generations of ICs to overcome the bottlenecks on speed and reliability present with the current Al based wiring. A new set of challenges brought to the forefront when copper replaces aluminum, have to be met and resolved to make it a viable option. Unit step processes related to copper technology have been under development for the last few years. In this work, the application of copper as the interconnect material in multilevel structures with SiO2 as the interlevel dielectric has been explored, with emphasis on integration issues and complete process realization. Interconnect definition was achieved by the Dual Damascene approach using chemical mechanical polishing of oxide and copper. The choice of materials used as adhesion promoter/diffusion barrier included Ti, Ta and CVD TiN. Two different polish chemistries (NH4OH or HNO3 based) were used to form the interconnects. The diffusion barrier was removed during polishing (in the case of TiN) or by a post CMP etch (as with Ti or Ta). Copper surface passivation was performed using boron implantation and PECVD nitride encapsulation. The interlevel dielectric way composed of a multilayer stack of PECVD SiO2 and SixNy. A baseline process sequence which ensured the mechanical and thermal compatibility of the different unit steps was first created. A comprehensive test vehicle was designed and test structures were fabricated using the process flow developed. Suitable modifications were subsequently introduced in the sequence as and when processing problems were encountered. Electrical characterization was performed on the fabricated devices, interconnects, contacts and vias. The structures were subjected to thermal stressing to assess their stability and performance. The measurement of interconnect sheet resistances revealed lower copper loss due to dishing on samples polished using HNO3 based slurry. Interconnect resistances remained stable upto 400o

U.S. Laws and Regulations for Renewable Energy Grid Interconnections

Energy Technology Data Exchange (ETDEWEB)

Chernyakhovskiy, Ilya [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States); McLaren, Joyce [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miller, Mackay [National Renewable Energy Lab. (NREL), Golden, CO (United States); Geller, Nina [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-09-01

Rapidly declining costs of wind and solar energy technologies, increasing concerns about the environmental and climate change impacts of fossil fuels, and sustained investment in renewable energy projects all point to a not-so-distant future in which renewable energy plays a pivotal role in the electric power system of the 21st century. In light of public pressures and market factors that hasten the transition towards a low-carbon system, power system planners and regulators are preparing to integrate higher levels of variable renewable generation into the grid. Updating the regulations that govern generator interconnections and operations is crucial to ensure system reliability while creating an enabling environment for renewable energy development. This report presents a chronological review of energy laws and regulations concerning grid interconnection procedures in the United States, highlighting the consequences of policies for renewable energy interconnections. Where appropriate, this report places interconnection policies and their impacts on renewable energy within the broader context of power market reform.

Photovoltaic sub-cell interconnects

Energy Technology Data Exchange (ETDEWEB)

van Hest, Marinus Franciscus Antonius Maria; Swinger Platt, Heather Anne

2017-05-09

Photovoltaic sub-cell interconnect systems and methods are provided. In one embodiment, a photovoltaic device comprises a thin film stack of layers deposited upon a substrate, wherein the thin film stack layers are subdivided into a plurality of sub-cells interconnected in series by a plurality of electrical interconnection structures; and wherein the plurality of electrical interconnection structures each comprise no more than two scribes that penetrate into the thin film stack layers.

Superconducting Multilayer High-Density Flexible Printed Circuit Board for Very High Thermal Resistance Interconnections

Science.gov (United States)

de la Broïse, Xavier; Le Coguie, Alain; Sauvageot, Jean-Luc; Pigot, Claude; Coppolani, Xavier; Moreau, Vincent; d'Hollosy, Samuel; Knarosovski, Timur; Engel, Andreas

2018-05-01

We have successively developed two superconducting flexible PCBs for cryogenic applications. The first one is monolayer, includes 552 tracks (10 µm wide, 20 µm spacing), and receives 24 wire-bonded integrated circuits. The second one is multilayer, with one track layer between two shielding layers interconnected by microvias, includes 37 tracks, and can be interconnected at both ends by wire bonding or by connectors. The first cold measurements have been performed and show good performances. The novelty of these products is, for the first one, the association of superconducting materials with very narrow pitch and bonded integrated circuits and, for the second one, the introduction of a superconducting multilayer structure interconnected by vias which is, to our knowledge, a world-first.

Planning and design of the Gulf States interconnection

International Nuclear Information System (INIS)

Al Alawi, J.; Sud, S.; McGillis, D.

1994-01-01

On May 25, 1981, the six Arab state of Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates (UAE) formally ratified the charter of the organization named Co-operation Council for the Arab States of the Gulf. This has become more popularly known as the Gulf Cooperation Council (GCC). In the mid 1980s, the integration of the electric systems study in the GCC was initiated, and several possible interconnection schemes to provide for reserve sharing and generally more economic and flexible operation of the networks were proposed. The GCC subsequently asked for an update of this study and a recommended interconnection scheme. this update study was completed in 1990, and a definite scheme was proposed, which met with the approval of all GCC members. This presentation describes the proposed interconnection, the studies that led to its selection, and the associated management structure required for its implementation. the population of the GCC states, and their load, generating capacity, and the transmission systems are shown

Progress of impact ignition

International Nuclear Information System (INIS)

Murakami, M.; Nagatomo, H.; Johzaki, T.

2010-11-01

In impact ignition scheme, a portion of the fuel (the impactor) is accelerated to a super-high velocity, compressed by convergence, and collided with a precompressed main fuel. This collision generates shock waves in both the impactor and the main fuel. Since the density of the impactor is generally much lower than that of the main fuel, the pressure balance ensures that the shock-heated temperature of the impactor is significantly higher than that of the main fuel. Hence, the impactor can reach ignition temperature and thus become an igniter. Here we report major new results on recent impact ignition research: (1) A maximum velocity ∼ 1000 km/s has been achieved under the operation of NIKE KrF laser at Naval Research Laboratory (laser wavelength=0.25μm) in the use of a planar target made of plastic and (2) We have performed two-dimensional simulation for burn and ignition to show the feasibility of the impact ignition. (author)

Optics vs copper: from the perspective of "Thunderbolt" interconnect technology

Science.gov (United States)

Cheng, Hengju; Krause, Christine; Ko, Jamyuen; Gao, Miaobin; Liu, Guobin; Wu, Huichin; Qi, Mike; Lam, Chun-Chit

2013-02-01

Interconnect technology has been progressed at a very fast pace for the past decade. The signaling rates have steadily increased from 100:Mb/s to 25Gb/s. In every generation of interconnect technology evolution, optics always seems to take over at first, however, at the end, the cost advantage of copper wins over. Because of this, optical interconnects are limited to longer distance links where the attenuation in copper cable is too large for the integrated circuits to compensate. Optical interconnect has long been viewed as the premier solution in compared with copper interconnect. With the release of Thunderbolt technology, we are entering a new era in consumer electronics that runs at 10Gb/s line rate (20Gb/s throughput per connector interface). Thunderbolt interconnect technology includes both active copper cables and active optical cables as the transmission media which have very different physical characteristics. In order for optics to succeed in consumer electronics, several technology hurdles need to be cleared. For example, the optical cable needs to handle the consumer abuses such as pinch and bend. Also, the optical engine used in the active optical cable needs to be physically very small so that we don't change the looks and feels of the cable/connector. Most importantly, the cost of optics needs to come down significantly to effectively compete with the copper solution. Two interconnect technologies are compared and discussed on the relative cost, power consumption, form factor, density, and future scalability.

8. High power laser and ignition facilities

International Nuclear Information System (INIS)

Bayramian, A.J.; Beach, R.J.; Bibeau, C.

2002-01-01

This document gives a review of the various high power laser projects and ignition facilities in the world: the Mercury laser system and Electra (Usa), the krypton fluoride (KrF) laser and the HALNA (high average power laser for nuclear-fusion application) project (Japan), the Shenguang series, the Xingguang facility and the TIL (technical integration line) facility (China), the Vulcan peta-watt interaction facility (UK), the Megajoule project and its feasibility phase: the LIL (laser integration line) facility (France), the Asterix IV/PALS high power laser facility (Czech Republic), and the Phelix project (Germany). In Japan the 100 TW Petawatt Module Laser, constructed in 1997, is being upgraded to the world biggest peta-watt laser. Experiments have been performed with single-pulse large aperture e-beam-pumped Garpun (Russia) and with high-current-density El-1 KrF laser installation (Russia) to investigate Al-Be foil transmittance and stability to multiple e-beam irradiations. An article is dedicated to a comparison of debris shield impacts for 2 experiments at NIF (national ignition facility). (A.C.)

Ultra-precision fabrication of high density micro-optical backbone interconnections for data center and mobile application

Science.gov (United States)

Lohmann, U.; Jahns, J.; Wagner, T.; Werner, C.

2012-10-01

A microoptical 3D interconnection scheme and fabricated samples of this fiberoptical multi-channel interconnec- tion with an actual capacity of 144 channels were shown. Additionally the aspects of micrometer-fabrication of such microoptical interconnection modules in the view of alignment-tolerances were considered. For the realiza- tion of the interconnection schemes, the approach of planar-integrated free space optics (PIFSO) is used with its well known advantages. This approach offers the potential for complex interconnectivity, and yet compact size.

An Integrated Ignition and Combustion System for Liquid Propellant Micro Propulsion

Science.gov (United States)

2008-06-26

using a microfin electrode array. They demonstrated successful gasification and ignition of the liquid propellant using this concept. The concept has...Transition to Detonation of Stoichiometric Ethylene/Oxygen in Microscale Tubes (with M-H. Wu, M.P. Burke, and S.F. Son) Proceedings of the

Transverse liquid fuel jet breakup, burning, and ignition

Energy Technology Data Exchange (ETDEWEB)

Li, H.

1990-01-01

An analytical/numerical study of the breakup, burning, and ignition of liquid fuels injected transversely into a hot air stream is conducted. The non-reacting liquid jet breakup location is determined by the local sonic point criterion first proposed by Schetz, et al. (1980). Two models, one employing analysis of an elliptical jet cross-section and the other employing a two-dimensional blunt body to represent the transverse jet, have been used for sonic point calculations. An auxiliary criterion based on surface tension stability is used as a separate means of determining the breakup location. For the reacting liquid jet problem, a diffusion flame supported by a one-step chemical reaction within the gaseous boundary layer is solved along the ellipse surface in subsonic crossflow. Typical flame structures and concentration profiles have been calculated for various locations along the jet cross-section as a function of upstream Mach numbers. The integrated reaction rate along the jet cross-section is used to predict ignition position, which is found to be situated near the stagnation point. While a multi-step reaction is needed to represent the ignition process more accurately, the present calculation does yield reasonable predictions concerning ignition along a curved surface.

Management and use of electric interconnections in 2008

International Nuclear Information System (INIS)

2009-07-01

Major progress was made throughout 2008 in border congestion management and market integration. A number of projects were carried out, including the creation of a single auction platform for the Central-West region (CASC-CWE) and the first centre for regional coordination (Coreso SA) to better control real-time flow, thus laying the foundations for future network management on a regional scale. Such progress encourages more improvements still, which should take effect some time in 2009 and should constitute an important stage in creating an integrated European electricity market. The more significant expected advances notably include the implementation of a single, harmonised set of bidding rules covering the entire Central-West region, which would include introducing the principle of automatic resale of capacity (use-it-or-sell-it); the launch of the second phase of the BALIT project for reciprocal adjusting exchanges between France and England; the introduction of a compensation scheme for curtailments of capacity based on the differences in pricing at Power Exchanges over the France-Spain interconnection; and finally the elaboration of the very first regional reports by regulators on the management and use of interconnections. The launch of the market coupling in the Central-West region, planned for March 2010, will unquestionably be a key event in market integration. In addition to substantially improving the use of the region's interconnections, it will offer significant new perspectives in market organisation (such as the future role and status of organised markets as regards day-ahead activity). The work of network operators on the flow-based aspect of the project will also enable improvements in transparency and coordination when calculating interconnection capacities, and could, in the long-run, open debates on changing the market design. However, of the issues raised in CRE's second report on management and use of interconnections, several have

Equilibrium ignition for ICF capsules

International Nuclear Information System (INIS)

Lackner, K.S.; Colgate, S.A.; Johnson, N.L.; Kirkpatrick, R.C.; Menikoff, R.; Petschek, A.G.

1993-01-01

There are two fundamentally different approaches to igniting DT fuel in an ICF capsule which can be described as equilibrium and hot spot ignition. In both cases, a capsule which can be thought of as a pusher containing the DT fuel is imploded until the fuel reaches ignition conditions. In comparing high-gain ICF targets using cryogenic DT for a pusher with equilibrium ignition targets using high-Z pushers which contain the radiation. The authors point to the intrinsic advantages of the latter. Equilibrium or volume ignition sacrifices high gain for lower losses, lower ignition temperature, lower implosion velocity and lower sensitivity of the more robust capsule to small fluctuations and asymmetries in the drive system. The reduction in gain is about a factor of 2.5, which is small enough to make the more robust equilibrium ignition an attractive alternative

32 x 16 CMOS smart pixel array for optical interconnects

Science.gov (United States)

Kim, Jongwoo; Guilfoyle, Peter S.; Stone, Richard V.; Hessenbruch, John M.; Choquette, Kent D.; Kiamilev, Fouad E.

2000-05-01

Free space optical interconnects can increase throughput capacities and eliminate much of the energy consumption required for `all electronic' systems. High speed optical interconnects can be achieved by integrating optoelectronic devices with conventional electronics. Smart pixel arrays have been developed which use optical interconnects. An individual smart pixel cell is composed of a vertical cavity surface emitting laser (VCSEL), a photodetector, an optical receiver, a laser driver, and digital logic circuitry. Oxide-confined VCSELs are being developed to operate at 850 nm with a threshold current of approximately 1 mA. Multiple quantum well photodetectors are being fabricated from AlGaAs for use with the 850 nm VCSELs. The VCSELs and photodetectors are being integrated with complementary metal oxide semiconductor (CMOS) circuitry using flip-chip bonding. CMOS circuitry is being integrated with a 32 X 16 smart pixel array. The 512 smart pixels are serially linked. Thus, an entire data stream may be clocked through the chip and output electrically by the last pixel. Electrical testing is being performed on the CMOS smart pixel array. Using an on-chip pseudo random number generator, a digital data sequence was cycled through the chip verifying operation of the digital circuitry. Although, the prototype chip was fabricated in 1.2 micrometers technology, simulations have demonstrated that the array can operate at 1 Gb/s per pixel using 0.5 micrometers technology.

Progress Towards Ignition on the National Ignition Facility

Science.gov (United States)

Edwards, John

2012-10-01

Since completion of the National Ignition Facility (NIF) construction project in March 2009, a wide variety of diagnostics, facility infrastructure, and experimental platforms have been commissioned in pursuit of generating the conditions necessary to reach thermonuclear ignition in the laboratory via the inertial confinement approach. NIF's capabilities and infrastructure include over 50 X-ray, optical, and nuclear diagnostics systems and the ability to shoot cryogenic DT layered capsules. There are two main approaches to ICF: direct drive in which laser light impinges directly on a capsule containing a solid layer of DT fuel, and indirect drive in which the laser light is first converted to thermal X-rays. To date NIF has been conducting experiments using the indirect drive approach, injecting up to 1.8MJ of ultraviolet light (0.35 micron) into 1 cm scale cylindrical gold or gold-coated uranium, gas-filled hohlraums, to implode 1mm radius plastic capsules containing solid DT fuel layers. In order to achieve ignition conditions the implosion must be precisely controlled. The National Ignition Campaign (NIC), an international effort with the goal of demonstrating thermonuclear burn in the laboratory, is making steady progress toward this. Utilizing precision pulse-shaping experiments in early 2012 the NIC achieve fuel rhoR of approximately 1.2 gm/cm^2 with densities of around 600-800 g/cm^3 along with neutron yields within about a factor of 5 necessary to enter a regime in which alpha particle heating will become important. To achieve these results, experimental platforms were developed to carefully control key attributes of the implosion. This talk will review NIF's capabilities and the progress toward ignition, as well as the physics of ignition targets on NIF and on other facilities. Acknowledgement: this work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Cone-guided fast ignition with no imposed magnetic fields

Directory of Open Access Journals (Sweden)

Strozzi D.

2013-11-01

Full Text Available Simulations are presented of ignition-scale fast ignition targets with the integrated Zuma-Hydra PIC-hydrodynamic capability. We consider a spherical DT fuel assembly with a carbon cone, and an artificially-collimated fast electron source. We study the role of E and B fields and the fast electron energy spectrum. For mono-energetic 1.5 MeV fast electrons, without E and B fields, ignition can be achieved with fast electron energy Efig = 30kJ. This is 3.5× the minimal deposited ignition energy of 8.7 kJ for our fuel density of 450 g/cm3. Including E and B fields with the resistive Ohm's law E = ηJb gives Efig = 20kJ, while using the full Ohm's law gives Efig > 40 kJ. This is due to magnetic self-guiding in the former case, and ∇n ×∇T magnetic fields in the latter. Using a realistic, quasi two-temperature energy spectrum derived from PIC laser-plasma simulations increases Efig to (102, 81, 162 kJ for (no E/B, E = ηJb, full Ohm's law. Such electrons are too energetic to stop in the optimal hot spot depth.

High frequency ignition arrangement

Energy Technology Data Exchange (ETDEWEB)

Canup, R E

1977-03-03

The invention concerns an HF ignition arrangement for combustion engines with a transistor oscillator. As this oscillator requires a current of 10A, with peak currents up to about 50A, it is not sensible to take this current through the remote ignition switch for switching it on and off. According to the invention the HF high voltage transformer of the ignition is provided with a control winding, which only requires a few milliamps DC and which can therefore be switched via the ignition switch. If the ignition switch is in the 'running' position, then a premagnetising DC current flows through the control winding, which suppresses the oscillation of the oscillator which has current flowing through it, until this current is interrupted by the interruptor contacts controlled by the combustion engine, so that the oscillations of the oscillator start immediately; the oscillator only continues to oscillate during the period during which the interruptor contacts controlled by the machine are open and interrupt the premagnetisation current. The control winding is short circuited in the 'off' position of the ignition switch.

Multi-gigabit optical interconnects for next-generation on-board digital equipment

Science.gov (United States)

Venet, Norbert; Favaro, Henri; Sotom, Michel; Maignan, Michel; Berthon, Jacques

2017-11-01

Parallel optical interconnects are experimentally assessed as a technology that may offer the high-throughput data communication capabilities required to the next-generation on-board digital processing units. An optical backplane interconnect was breadboarded, on the basis of a digital transparent processor that provides flexible connectivity and variable bandwidth in telecom missions with multi-beam antenna coverage. The unit selected for the demonstration required that more than tens of Gbit/s be supported by the backplane. The demonstration made use of commercial parallel optical link modules at 850 nm wavelength, with 12 channels running at up to 2.5 Gbit/s. A flexible optical fibre circuit was developed so as to route board-to-board connections. It was plugged to the optical transmitter and receiver modules through 12-fibre MPO connectors. BER below 10-14 and optical link budgets in excess of 12 dB were measured, which would enable to integrate broadcasting. Integration of the optical backplane interconnect was successfully demonstrated by validating the overall digital processor functionality.

The Development of an IMU Integrated Clothes for Postural Monitoring Using Conductive Yarn and Interconnecting Technology

Directory of Open Access Journals (Sweden)

Sung-Won Kang

2017-11-01

Full Text Available Spinal disease is a common yet important condition that occurs because of inappropriate posture. Prevention could be achieved by continuous posture monitoring, but most measurement systems cannot be used in daily life due to factors such as burdensome wires and large sensing modules. To improve upon these weaknesses, we developed comfortable “smart wear” for posture measurement using conductive yarn for circuit patterning and a flexible printed circuit board (FPCB for interconnections. The conductive yarn was made by twisting polyester yarn and metal filaments, and the resistance per unit length was about 0.05 Ω/cm. An embroidered circuit was made using the conductive yarn, which showed increased yield strength and uniform electrical resistance per unit length. Circuit networks of sensors and FPCBs for interconnection were integrated into clothes using a computer numerical control (CNC embroidery process. The system was calibrated and verified by comparing the values measured by the smart wear with those measured by a motion capture camera system. Six subjects performed fixed movements and free computer work, and, with this system, we were able to measure the anterior/posterior direction tilt angle with an error of less than 4°. The smart wear does not have excessive wires, and its structure will be optimized for better posture estimation in a later study.

Reaching ignition in the tokamak

International Nuclear Information System (INIS)

Furth, H.P.

1985-06-01

This review covers the following areas: (1) the physics of burning plasmas, (2) plasma physics requirements for reaching ignition, (3) design studies for ignition devices, and (4) prospects for an ignition project

Technology Development of a Fiber Optic-Coupled Laser Ignition System for Multi-Combustor Rocket Engines

Science.gov (United States)

Trinh, Huu P.; Early, Jim; Osborne, Robin; Thomas, Matthew E.; Bossard, John A.

2002-01-01

This paper addresses the progress of technology development of a laser ignition system at NASA Marshall Space Flight Center (MSFC). The first two years of the project focus on comprehensive assessments and evaluations of a novel dual-pulse laser concept, flight- qualified laser system, and the technology required to integrate the laser ignition system to a rocket chamber. With collaborations of the Department of Energy/Los Alamos National Laboratory (LANL) and CFD Research Corporation (CFDRC), MSFC has conducted 26 hot fire ignition tests with lab-scale laser systems. These tests demonstrate the concept feasibility of dual-pulse laser ignition to initiate gaseous oxygen (GOX)/liquid kerosene (RP-1) combustion in a rocket chamber. Presently, a fiber optic- coupled miniaturized laser ignition prototype is being implemented at the rocket chamber test rig for future testing. Future work is guided by a technology road map that outlines the work required for maturing a laser ignition system. This road map defines activities for the next six years, with the goal of developing a flight-ready laser ignition system.

Application of transient ignition model to multi-canister (MCO) accident analysis

International Nuclear Information System (INIS)

Kummerer, M.

1996-01-01

The potential for ignition of spent nuclear fuel in a Multi-Canister Overpack (MCO) is examined. A transient model is applied to calculate the highest ambient gas temperature outside an MCO wall tube or shipping cask for which a stable temperature condition exists. This integral analysis couples reaction kinetics with a description of the MCO configuration, heat and mass transfer, and fission product phenomena. It thereby allows ignition theory to be applied to various complex scenarios, including MCO water loss accidents and dry MCO air ingression

Interconnection policy: a theoretical survey

Directory of Open Access Journals (Sweden)

César Mattos

2003-01-01

Full Text Available This article surveys the theoretical foundations of interconnection policy. The requirement of an interconnection policy should not be taken for granted in all circumstances, even considering the issue of network externalities. On the other hand, when it is required, an encompassing interconnection policy is usually justified. We provide an overview of the theory on interconnection pricing that results in several different prescriptions depending on which problem the regulator aims to address. We also present a survey on the literature on two-way interconnection.

Ignition tuning for the National Ignition Campaign

Directory of Open Access Journals (Sweden)

Landen O.

2013-11-01

Full Text Available The overall goal of the indirect-drive inertial confinement fusion [1] tuning campaigns [2] is to maximize the probability of ignition by experimentally correcting for likely residual uncertainties in the implosion and hohlraum physics [3] used in our radiation-hydrodynamic computational models, and by checking for and resolving unexpected shot-to-shot variability in performance [4]. This has been started successfully using a variety of surrogate capsules that set key laser, hohlraum and capsule parameters to maximize ignition capsule implosion velocity, while minimizing fuel adiabat, core shape asymmetry and ablator-fuel mix.

Laser ignition - Spark plug development and application in reciprocating engines

Science.gov (United States)

Pavel, Nicolaie; Bärwinkel, Mark; Heinz, Peter; Brüggemann, Dieter; Dearden, Geoff; Croitoru, Gabriela; Grigore, Oana Valeria

2018-03-01

solutions for positioning of the laser spark plug, i.e. placing it apart from or directly on the engine, are introduced. The path taken from the first solution proposed, to build a compact laser suitable for ignition, to the practical realization of a laser spark plug is described. Results obtained by ignition of automobile test engines, with laser devices that resemble classical spark plugs, are specifically discussed. It is emphasized that technological advances have brought this method of laser ignition close to the application and installation in automobiles powered by gasoline engines. Achievements made in the laser ignition of natural gas engines are outlined, as well as the utilization of laser ignition in other applications. Scientific and technical advances have allowed realization of laser devices with multiple (up to four) beam outputs, but many other important aspects (such as integration, thermal endurance or vibration strength) are still to be solved. Recent results of multi-beam ignition of a single-cylinder engine in a test bench set-up are encouraging and have led to increased research interest in this direction. A fundamental understanding of the processes involved in laser ignition is crucial in order to exploit the technology's full potential. Therefore, several measurement techniques, primarily optical types, used to characterize the laser ignition process are reviewed in this work.

Interconnection blocks: a method for providing reusable, rapid, multiple, aligned and planar microfluidic interconnections

DEFF Research Database (Denmark)

Sabourin, David; Snakenborg, Detlef; Dufva, Hans Martin

2009-01-01

In this paper a method is presented for creating 'interconnection blocks' that are re-usable and provide multiple, aligned and planar microfluidic interconnections. Interconnection blocks made from polydimethylsiloxane allow rapid testing of microfluidic chips and unobstructed microfluidic observ...

Maghreb: from the interconnection of power grids to energetic integration. Energy supply in Maghreb

International Nuclear Information System (INIS)

Keramane, Abdelnour

2015-10-01

In a first article, the author first comments the levels of electricity production and consumption in Maghreb, and how this production is distributed among different sources in Algeria, Morocco and Tunisia. He comments how electric power utilities in these countries decided to collaborate to create common bodies and to implement an interconnection between their power grids, but also with Libya and Spain. He outlines that the three countries aim at creating a common Maghreb market of electricity and then at being integrated into the European market. The author then discusses the planned evolution of the energy mix, and more particularly the role different energies (hydrocarbons, coal, nuclear, renewable energies) may have in the future. He finally discusses the challenges and issues associated with a passage from collaboration to integration. In the second article, the author proposes an overview of energy supply in Algeria, Morocco and Tunisia. He comments data related to primary energy consumption, to the prevalence of fossil energies, to the marginal share of renewable energies, to energy efficiency, and to carbon footprint. For some of these issues, data are given for 2000 and 2011, for each country, for the three countries together and for the world. The author comments trends, evolutions and perspectives for the different energy resources: hydrocarbons and renewable sources

Lateral buckling and mechanical stretchability of fractal interconnects partially bonded onto an elastomeric substrate

International Nuclear Information System (INIS)

Fu, Haoran; Xu, Sheng; Rogers, John A.; Xu, Renxiao; Huang, Yonggang; Jiang, Jianqun; Zhang, Yihui

2015-01-01

Fractal-inspired designs for interconnects that join rigid, functional devices can ensure mechanical integrity in stretchable electronic systems under extreme deformations. The bonding configuration of such interconnects with the elastomer substrate is crucial to the resulting deformation modes, and therefore the stretchability of the entire system. In this study, both theoretical and experimental analyses are performed for postbuckling of fractal serpentine interconnects partially bonded to the substrate. The deformation behaviors and the elastic stretchability of such systems are systematically explored, and compared to counterparts that are not bonded at all to the substrate

Reconfigurable optical interconnection network for multimode optical fiber sensor arrays

Science.gov (United States)

Chen, R. T.; Robinson, D.; Lu, H.; Wang, M. R.; Jannson, T.; Baumbick, R.

1992-01-01

A single-source, single-detector architecture has been developed to implement a reconfigurable optical interconnection network multimode optical fiber sensor arrays. The network was realized by integrating LiNbO3 electrooptic (EO) gratings working at the Raman Na regime and a massive fan-out waveguide hologram (WH) working at the Bragg regime onto a multimode glass waveguide. The glass waveguide utilized the whole substrate as a guiding medium. A 1-to-59 massive waveguide fan-out was demonstrated using a WH operating at 514 nm. Measured diffraction efficiency of 59 percent was experimentally confirmed. Reconfigurability of the interconnection was carried out by generating an EO grating through an externally applied electric field. Unlike conventional single-mode integrated optical devices, the guided mode demonstrated has an azimuthal symmetry in mode profile which is the same as that of a fiber mode.

Review: laser ignition for aerospace propulsion

Directory of Open Access Journals (Sweden)

Steven A. O’Briant

2016-03-01

This paper aims to provide the reader an overview of advanced ignition methods, with an emphasis on laser ignition and its applications to aerospace propulsion. A comprehensive review of advanced ignition systems in aerospace applications is performed. This includes studies on gas turbine applications, ramjet and scramjet systems, and space and rocket applications. A brief overview of ignition and laser ignition phenomena is also provided in earlier sections of the report. Throughout the reading, research papers, which were presented at the 2nd Laser Ignition Conference in April 2014, are mentioned to indicate the vast array of projects that are currently being pursued.

Modelling auto ignition of hydrogen in a jet ignition pre-chamber

Energy Technology Data Exchange (ETDEWEB)

Boretti, Alberto A. [School of Science and Engineering, University of Ballarat, PO Box 663, Ballarat, Victoria 3353 (Australia)

2010-04-15

Spark-less jet ignition pre-chambers are enablers of high efficiencies and load control by quantity of fuel injected when coupled with direct injection of main chamber fuel, thus permitting always lean burn bulk stratified combustion. Towards the end of the compression stroke, a small quantity of hydrogen is injected within the pre-chamber, where it mixes with the air entering from the main chamber. Combustion of the air and fuel mixture then starts within the pre-chamber because of the high temperature of the hot glow plug, and then jets of partially combusted hot gases enter the main chamber igniting there in the bulk, over multiple ignition points, lean stratified mixtures of air and fuel. The paper describes the operation of the spark-less jet ignition pre-chamber coupling CFD and CAE engine simulations to allow component selection and engine performance evaluation. (author)

Assessing the prospects for achieving double-shell ignition on the National Ignition Facility using vacuum hohlraums

International Nuclear Information System (INIS)

Amendt, Peter; Cerjan, C.; Hamza, A.; Hinkel, D. E.; Milovich, J. L.; Robey, H. F.

2007-01-01

The goal of demonstrating ignition on the National Ignition Facility [J. D. Lindl et al., Phys. Plasmas 11, 339 (2003)] has motivated a revisit of double-shell (DS) targets as a complementary path to the cryogenic baseline approach. Expected benefits of DS ignition targets include noncryogenic deuterium-tritium (DT) fuel preparation, minimal hohlraum-plasma-mediated laser backscatter, low threshold-ignition temperatures (≅4 keV) for relaxed hohlraum x-ray flux asymmetry tolerances, and minimal (two-) shock timing requirements. On the other hand, DS ignition presents several formidable challenges, encompassing room-temperature containment of high-pressure DT (≅790 atm) in the inner shell, strict concentricity requirements on the two shells ( 2 nanoporous aerogels with suspended Cu particles. A prototype demonstration of an ignition DS is planned for 2008, incorporating the needed novel nanomaterials science developments and the required fabrication tolerances for a realistic ignition attempt after 2010

Area array interconnection handbook

CERN Document Server

Totta, Paul A

2012-01-01

Microelectronic packaging has been recognized as an important "enabler" for the solid­ state revolution in electronics which we have witnessed in the last third of the twentieth century. Packaging has provided the necessary external wiring and interconnection capability for transistors and integrated circuits while they have gone through their own spectacular revolution from discrete device to gigascale integration. At IBM we are proud to have created the initial, simple concept of flip chip with solder bump connections at a time when a better way was needed to boost the reliability and improve the manufacturability of semiconductors. The basic design which was chosen for SLT (Solid Logic Technology) in the 1960s was easily extended to integrated circuits in the '70s and VLSI in the '80s and '90s. Three I/O bumps have grown to 3000 with even more anticipated for the future. The package families have evolved from thick-film (SLT) to thin-film (metallized ceramic) to co-fired multi-layer ceramic. A later famil...

Reversed field pinch ignition requirements

International Nuclear Information System (INIS)

Werley, K.A.

1991-01-01

Plasma models are described and used to calculated numerically the transport confinement (nτ E ) requirements and steady state operation points for both the reversed field pinch (RFP) and the tokamak. The models are used to examine the CIT tokamak ignition conditions and the RFP experimental and ignition conditions. Physics differences between RFPs and tokamaks and their consequences for a D-T ignition machine are discussed. Compared with a tokamak, the ignition RFP has many physics advantages, including Ohmic heating to ignition (no need for auxiliary heating systems), higher beta, lower ignition current, less sensitivity of ignition requirements to impurity effects, no hard disruptions (associated with beta or density limits) and successful operation with high radiation fractions (f RAD ∼ 0.95). These physics advantages, coupled with important engineering advantages associated with lower external magnetic field, larger aspect ratios and smaller plasma cross-sections, translate to significant cost reductions for both ignition and reactor applications. The primary drawback of the RFP is the uncertainty that the present scaling will extrapolate to reactor regimes. Devices that are under construction should go a long way toward resolving this scaling uncertainty. The 4 MA ZTH is expected to extend the nτ E transport scaling data by three orders of magnitude above the results of ZT-40M, and, if the present scaling holds, ZTH is expected to achieve a D-T equivalent scientific energy breakeven, Q = 1. A base case RFP ignition point is identified with a plasma current of 8.1 MA and no auxiliary heating. (author). 19 refs, 11 figs, 3 tabs

Oahu Wind Integration and Transmission Study (OWITS): Hawaiian Islands Transmission Interconnection Project

Energy Technology Data Exchange (ETDEWEB)

Woodford, D.

2011-02-01

This report provides an independent review included an initial evaluation of the technical configuration and capital costs of establishing an undersea cable system and examining impacts to the existing electric transmission systems as a result of interconnecting the islands.

Tokamak and RFP ignition requirements

International Nuclear Information System (INIS)

Werley, K.A.

1991-01-01

A plasma model is applied to calculate numerically transport- confinement (nτ E ) requirements and steady-state operation tokamak. The CIT tokamak and RFP ignition conditions are examined. Physics differences between RFP and tokamaks, and their consequences for a DT ignition machine, are discussed. The ignition RFP, compared to a tokamak, has many physics advantages, including ohmic heating to ignition (no need for auxiliary heating systems), higher beta, low ignition current, less sensitivity of ignition requirements to impurity effects, no hard disruptions (associated with beta or density limits), and successful operation with high radiation fractions (f RAD ∼ 0.95). These physics advantages, coupled with important engineering advantages associated with lower external magnetic fields, larger aspect ratios, and smaller plasma cross sections translate into significant cost reductions for both ignition and power reactor. The primary drawback of the RFP is the uncertainty that the present confinement scaling will extrapolate to reactor regimes. The 4-MA ZTH was expected to extend the nτ E transport scaling data three order of magnitude above ZT-40M results, and if the present scaling held, to achieve a DT-equivalent scientific energy breakeven, Q=1. A basecase RFP ignition point is identified with a plasma current of 8.1 MA and no auxiliary heating. 16 refs., 4 figs., 1 tab

Ignition of Aluminum Particles and Clouds

Energy Technology Data Exchange (ETDEWEB)

Kuhl, A L; Boiko, V M

2010-04-07

Here we review experimental data and models of the ignition of aluminum (Al) particles and clouds in explosion fields. The review considers: (i) ignition temperatures measured for single Al particles in torch experiments; (ii) thermal explosion models of the ignition of single Al particles; and (iii) the unsteady ignition Al particles clouds in reflected shock environments. These are used to develop an empirical ignition model appropriate for numerical simulations of Al particle combustion in shock dispersed fuel explosions.

Ignition parameters and early flame kernel development of laser-ignited combustible gas mixtures

International Nuclear Information System (INIS)

Kopecek, H.; Wintner, E.; Ruedisser, D.; Iskra, K.; Neger, T.

2002-01-01

Full text: Laser induced breakdown of focused pulsed laser radiation, the subsequent plasma formation and thermalization offers a possibility of ignition of combustible gas mixtures free from electrode interferences, an arbitrary choice of the location within the medium and exact timing regardless of the degree of turbulence. The development and the decreasing costs of solid state laser technologies approach the pay-off for the higher complexity of such an ignition system due to several features unique to laser ignition. The feasability of laser ignition was demonstrated in an 1.5 MW(?) natural gas engine, and several investigations were performed to determine optimal ignition energies, focus shapes and laser wavelengths. The early flame kernel development was investigated by time resolved planar laser induced fluorescence of the OH-radical which occurs predominantly in the flame front. The flame front propagation showed typical features like toroidal initial flame development, flame front return and highly increased flame speed along the laser focus axis. (author)

Interconnected networks

CERN Document Server

2016-01-01

This volume provides an introduction to and overview of the emerging field of interconnected networks which include multi layer or multiplex networks, as well as networks of networks. Such networks present structural and dynamical features quite different from those observed in isolated networks. The presence of links between different networks or layers of a network typically alters the way such interconnected networks behave – understanding the role of interconnecting links is therefore a crucial step towards a more accurate description of real-world systems. While examples of such dissimilar properties are becoming more abundant – for example regarding diffusion, robustness and competition – the root of such differences remains to be elucidated. Each chapter in this topical collection is self-contained and can be read on its own, thus making it also suitable as reference for experienced researchers wishing to focus on a particular topic.

Fiber bundle probes for interconnecting miniaturized medical imaging devices

Science.gov (United States)

Zamora, Vanessa; Hofmann, Jens; Marx, Sebastian; Herter, Jonas; Nguyen, Dennis; Arndt-Staufenbiel, Norbert; Schröder, Henning

2017-02-01

Miniaturization of medical imaging devices will significantly improve the workflow of physicians in hospitals. Photonic integrated circuit (PIC) technologies offer a high level of miniaturization. However, they need fiber optic interconnection solutions for their functional integration. As part of European funded project (InSPECT) we investigate fiber bundle probes (FBPs) to be used as multi-mode (MM) to single-mode (SM) interconnections for PIC modules. The FBP consists of a set of four or seven SM fibers hexagonally distributed and assembled into a holder that defines a multicore connection. Such a connection can be used to connect MM fibers, while each SM fiber is attached to the PIC module. The manufacturing of these probes is explored by using well-established fiber fusion, epoxy adhesive, innovative adhesive and polishing techniques in order to achieve reliable, low-cost and reproducible samples. An innovative hydrofluoric acid-free fiber etching technology has been recently investigated. The preliminary results show that the reduction of the fiber diameter shows a linear behavior as a function of etching time. Different etch rate values from 0.55 μm/min to 2.3 μm/min were found. Several FBPs with three different type of fibers have been optically interrogated at wavelengths of 630nm and 1550nm. Optical losses are found of approx. 35dB at 1550nm for FBPs composed by 80μm fibers. Although FBPs present moderate optical losses, they might be integrated using different optical fibers, covering a broad spectral range required for imaging applications. Finally, we show the use of FBPs as promising MM-to-SM interconnects for real-world interfacing to PIC's.

Interconnection of Distributed Energy Resources

Energy Technology Data Exchange (ETDEWEB)

Reiter, Emerson [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-04-19

This is a presentation on interconnection of distributed energy resources, including the relationships between different aspects of interconnection, best practices and lessons learned from different areas of the U.S., and an update on technical advances and standards for interconnection.

A comparative experimental study on engine operating on premixed charge compression ignition and compression ignition mode

Directory of Open Access Journals (Sweden)

Bhiogade Girish E.

2017-01-01

Full Text Available New combustion concepts have been recently developed with the purpose to tackle the problem of high emissions level of traditional direct injection Diesel engines. A good example is the premixed charge compression ignition combustion. A strategy in which early injection is used causing a burning process in which the fuel burns in the premixed condition. In compression ignition engines, soot (particulate matter and NOx emissions are an extremely unsolved issue. Premixed charge compression ignition is one of the most promising solutions that combine the advantages of both spark ignition and compression ignition combustion modes. It gives thermal efficiency close to the compression ignition engines and resolves the associated issues of high NOx and particulate matter, simultaneously. Premixing of air and fuel preparation is the challenging part to achieve premixed charge compression ignition combustion. In the present experimental study a diesel vaporizer is used to achieve premixed charge compression ignition combustion. A vaporized diesel fuel was mixed with the air to form premixed charge and inducted into the cylinder during the intake stroke. Low diesel volatility remains the main obstacle in preparing premixed air-fuel mixture. Exhaust gas re-circulation can be used to control the rate of heat release. The objective of this study is to reduce exhaust emission levels with maintaining thermal efficiency close to compression ignition engine.

Design of ignition targets for the National Ignition Facility

International Nuclear Information System (INIS)

Haan, S.W.; Dittrich, T.R.; Marinak, M.M.; Hinkel, D.E.

1999-01-01

This is a brief update on the work being done to design ignition targets for the National Ignition Facility. Updates are presented on three areas of current activity : improvements in modeling, work on a variety of targets spanning the parameter space of possible ignition targets ; and the setting of specifications for target fabrication and diagnostics. Highlights of recent activity include : a simulation of the Rayleigh-Taylor instability growth on an imploding capsule, done in 3D on a 72degree by 72degree wedge, with enough zones to resolve modes out to 100 ; and designs of targets at 250eV and 350eV, as well as the baseline 300 eV ; and variation of the central DT gas density, which influences both the Rayleigh-Taylor growth and the smoothness of the DT ice layer

Communication Requirements and Interconnect Optimization forHigh-End Scientific Applications

Energy Technology Data Exchange (ETDEWEB)

Kamil, Shoaib; Oliker, Leonid; Pinar, Ali; Shalf, John

2007-11-12

The path towards realizing peta-scale computing isincreasingly dependent on building supercomputers with unprecedentednumbers of processors. To prevent the interconnect from dominating theoverall cost of these ultra-scale systems, there is a critical need forhigh-performance network solutions whose costs scale linearly with systemsize. This work makes several unique contributions towards attaining thatgoal. First, we conduct one of the broadest studies to date of high-endapplication communication requirements, whose computational methodsinclude: finite-difference, lattice-bolzmann, particle in cell, sparselinear algebra, particle mesh ewald, and FFT-based solvers. Toefficiently collect this data, we use the IPM (Integrated PerformanceMonitoring) profiling layer to gather detailed messaging statistics withminimal impact to code performance. Using the derived communicationcharacterizations, we next present fit-trees interconnects, a novelapproach for designing network infrastructure at a fraction of thecomponent cost of traditional fat-tree solutions. Finally, we propose theHybrid Flexibly Assignable Switch Topology (HFAST) infrastructure, whichuses both passive (circuit) and active (packet) commodity switchcomponents to dynamically reconfigure interconnects to suit thetopological requirements of scientific applications. Overall ourexploration leads to a promising directions for practically addressingthe interconnect requirements of future peta-scale systems.

A metallic buried interconnect process for through-wafer interconnection

International Nuclear Information System (INIS)

Ji, Chang-Hyeon; Herrault, Florian; Allen, Mark G

2008-01-01

In this paper, we present the design, fabrication process and experimental results of electroplated metal interconnects buried at the bottom of deep silicon trenches with vertical sidewalls. A manual spray-coating process along with a unique trench-formation process has been developed for the electroplating of a metal interconnection structure at the bottom surface of the deep trenches. The silicon etch process combines the isotropic dry etch process and conventional Bosch process to fabricate a deep trench with angled top-side edges and vertical sidewalls. The resulting trench structure, in contrast to the trenches fabricated by wet anisotropic etching, enables spray-coated photoresist patterning with good sidewall and top-side edge coverage while maintaining the ability to form a high-density array of deep trenches without excessive widening of the trench opening. A photoresist spray-coating process was developed and optimized for the formation of electroplating mold at the bottom of 300 µm deep trenches having vertical sidewalls. A diluted positive tone photoresist with relatively high solid content and multiple coating with baking between coating steps has been experimentally proven to provide high quality sidewall and edge coverage. To validate the buried interconnect approach, a three-dimensional daisy chain structure having a buried interconnect as the bottom connector and traces on the wafer surface as the top conductor has been designed and fabricated

Study of complete interconnect reliability for a GaAs MMIC power amplifier

Science.gov (United States)

Lin, Qian; Wu, Haifeng; Chen, Shan-ji; Jia, Guoqing; Jiang, Wei; Chen, Chao

2018-05-01

By combining the finite element analysis (FEA) and artificial neural network (ANN) technique, the complete prediction of interconnect reliability for a monolithic microwave integrated circuit (MMIC) power amplifier (PA) at the both of direct current (DC) and alternating current (AC) operation conditions is achieved effectively in this article. As a example, a MMIC PA is modelled to study the electromigration failure of interconnect. This is the first time to study the interconnect reliability for an MMIC PA at the conditions of DC and AC operation simultaneously. By training the data from FEA, a high accuracy ANN model for PA reliability is constructed. Then, basing on the reliability database which is obtained from the ANN model, it can give important guidance for improving the reliability design for IC.

Analysis of cyclic variations during mode switching between spark ignition and controlled auto-ignition combustion operations

OpenAIRE

Chen, T; Zhao, H; Xie, H; He, B

2014-01-01

© IMechE 2014. Controlled auto-ignition, also known as homogeneous charge compression ignition, has been the subject of extensive research because of their ability to provide simultaneous reductions in fuel consumption and NOx emissions from a gasoline engine. However, due to its limited operation range, switching between controlled auto-ignition and spark ignition combustion is needed to cover the complete operating range of a gasoline engine for passenger car applications. Previous research...

Benefits of transmission interconnections

International Nuclear Information System (INIS)

Lyons, D.

2006-01-01

The benefits of new power transmission interconnections from Alberta were discussed with reference to the challenges and measures needed to move forward. Alberta's electricity system has had a long period of sustained growth in generation and demand and this trend is expected to continue. However, no new interconnections have been built since 1985 because the transmission network has not expanded in consequence with the growth in demand. As such, Alberta remains weakly interconnected with the rest of the western region. The benefits of stronger transmission interconnections include improved reliability, long-term generation capability, hydrothermal synergies, a more competitive market, system efficiencies and fuel diversity. It was noted that the more difficult challenges are not technical. Rather, the difficult challenges lie in finding an appropriate business model that recognizes different market structures. It was emphasized that additional interconnections are worthwhile and will require significant collaboration among market participants and governments. It was concluded that interties enable resource optimization between systems and their benefits far exceed their costs. tabs., figs

Effects of surface states on device and interconnect isolation in GaAs MESFET and InP MISFET integrated circuits

International Nuclear Information System (INIS)

Hasegawa, H.; Kitagawa, T.; Masuda, H.; Yano, H.; Ohno, H.

1985-01-01

Surface electrical breakdown and side-gating which cause failure of device and interconnect isolation are investigated for GaAs MESFET and InP MISFET integrated circuit structures. Striking differences in behavior are observed between GaAs and InP as regards to the surface conduction, surface breakdown and side-gating. These differences are shown to be related to the surface state properties of the insulator-semiconductor interface. In GaAs, high density of surface states rather than bulk trap states control the surface I-V characteristics and side-gating, causing serious premature avalanche breakdown and triggering side-gating at a low nominal field intensity of 1-3 kV/cm. On the other hand, InP MISFET integrated circuits are virtually free from these premature breakdown and side-gating effect under normal dark operating condition because of very low surface state density

The National Ignition Facility. The path to ignition and inertial fusion energy

International Nuclear Information System (INIS)

Eric Storm

2010-01-01

Complete text of publication follows. The National Ignition Facility (NIF), the world's largest and most energetic laser system built for studying inertial confinement fusion (ICF) and high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). NIF's 192 beams are capable of producing 1.8 MJ and 500 TW of ultraviolet light and are configured to create pressures as high as 100 GB, matter temperatures approaching 10 9 and densities over 1000 g/cm 3 . With these capabis70lities, the NIF will enable exploring scientific problems in strategic defense, basic science and fusion energy. One of the early NIF campaigns is focusing on demonstrating laboratory-scale thermonuclear ignition and burn to produce net fusion energy gains of 10-20 with 1.2 to 1.4 MJ of 0.35 μm light. NIF ignition experiments began late in FY2009 as part of the National Ignition Campaign (NIC). Participants of NIC include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory, and the University of Rochester Laboratory for Energetics (LLE) as well as variety of national and international collaborators. The results from these initial experiments show great promise for the relatively near-term achievement of ignition. Capsule implosion experiments at energies up to 1.2 MJ have demonstrated laser energetics, radiation temperatures, and symmetry control that scale to ignition conditions. Of particular importance is the demonstration of peak hohlraum temperatures near 300 eV with low overall backscatter less than 10%. Cryogenic target capability and additional diagnostics are being installed in preparation for layered target deuterium-tritium implosions to be conducted later in 2010. The goal for NIC is to demonstrate a predictable fusion experimental platform by the end of 2012. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of Inertial Fusion Energy (IFE) and

A Comparative Study of Cycle Variability of Laser Plug Ignition vs Classical Spark Plug Ignition in Combustion Engines

Science.gov (United States)

Done, Bogdan

2017-10-01

Over the past 30 years numerous studies and laboratory experiments have researched the use of laser energy to ignite gas and fuel-air mixtures. The actual implementation of this laser application has still to be fully achieved in a commercial automotive application. Laser Plug Ignition as a replacement for Spark Plug Ignition in the internal combustion engines of automotive vehicles, offers several potential benefits such as extending lean burn capability, reducing the cyclic variability between combustion cycles and decreasing the total amount of ignition costs, and implicitly weight and energy requirements. The paper presents preliminary results of cycle variability study carried on a SI Engine equipped with laser Plug Ignition system. Versus classic ignition system, the use of the laser Plug Ignition system assures the reduction of the combustion process variability, reflected in the lower values of the coefficient of variability evaluated for indicated mean effective pressure, maximum pressure, maximum pressure angle and maximum pressure rise rate. The laser plug ignition system was mounted on an experimental spark ignition engine and tested at the regime of 90% load and 2800 rev/min, at dosage of λ=1.1. Compared to conventional spark plug, laser ignition assures the efficiency at lean dosage.

Reliability analysis of magnetic logic interconnect wire subjected to magnet edge imperfections

Science.gov (United States)

Zhang, Bin; Yang, Xiaokuo; Liu, Jiahao; Li, Weiwei; Xu, Jie

2018-02-01

Nanomagnet logic (NML) devices have been proposed as one of the best candidates for the next generation of integrated circuits thanks to its substantial advantages of nonvolatility, radiation hardening and potentially low power. In this article, errors of nanomagnetic interconnect wire subjected to magnet edge imperfections have been evaluated for the purpose of reliable logic propagation. The missing corner defects of nanomagnet in the wire are modeled with a triangle, and the interconnect fabricated with various magnetic materials is thoroughly investigated by micromagnetic simulations under different corner defect amplitudes and device spacings. The results show that as the defect amplitude increases, the success rate of logic propagation in the interconnect decreases. More results show that from the interconnect wire fabricated with materials, iron demonstrates the best defect tolerance ability among three representative and frequently used NML materials, also logic transmission errors can be mitigated by adjusting spacing between nanomagnets. These findings can provide key technical guides for designing reliable interconnects. Project supported by the National Natural Science Foundation of China (No. 61302022) and the Scientific Research Foundation for Postdoctor of Air Force Engineering University (Nos. 2015BSKYQD03, 2016KYMZ06).

Two-stage Lagrangian modeling of ignition processes in ignition quality tester and constant volume combustion chambers

KAUST Repository

Alfazazi, Adamu

2016-08-10

The ignition characteristics of isooctane and n-heptane in an ignition quality tester (IQT) were simulated using a two-stage Lagrangian (TSL) model, which is a zero-dimensional (0-D) reactor network method. The TSL model was also used to simulate the ignition delay of n-dodecane and n-heptane in a constant volume combustion chamber (CVCC), which is archived in the engine combustion network (ECN) library (http://www.ca.sandia.gov/ecn). A detailed chemical kinetic model for gasoline surrogates from the Lawrence Livermore National Laboratory (LLNL) was utilized for the simulation of n-heptane and isooctane. Additional simulations were performed using an optimized gasoline surrogate mechanism from RWTH Aachen University. Validations of the simulated data were also performed with experimental results from an IQT at KAUST. For simulation of n-dodecane in the CVCC, two n-dodecane kinetic models from the literature were utilized. The primary aim of this study is to test the ability of TSL to replicate ignition timings in the IQT and the CVCC. The agreement between the model and the experiment is acceptable except for isooctane in the IQT and n-heptane and n-dodecane in the CVCC. The ability of the simulations to replicate observable trends in ignition delay times with regard to changes in ambient temperature and pressure allows the model to provide insights into the reactions contributing towards ignition. Thus, the TSL model was further employed to investigate the physical and chemical processes responsible for controlling the overall ignition under various conditions. The effects of exothermicity, ambient pressure, and ambient oxygen concentration on first stage ignition were also studied. Increasing ambient pressure and oxygen concentration was found to shorten the overall ignition delay time, but does not affect the timing of the first stage ignition. Additionally, the temperature at the end of the first stage ignition was found to increase at higher ambient pressure

In-memory interconnect protocol configuration registers

Energy Technology Data Exchange (ETDEWEB)

Cheng, Kevin Y.; Roberts, David A.

2017-09-19

Systems, apparatuses, and methods for moving the interconnect protocol configuration registers into the main memory space of a node. The region of memory used for storing the interconnect protocol configuration registers may also be made cacheable to reduce the latency of accesses to the interconnect protocol configuration registers. Interconnect protocol configuration registers which are used during a startup routine may be prefetched into the host's cache to make the startup routine more efficient. The interconnect protocol configuration registers for various interconnect protocols may include one or more of device capability tables, memory-side statistics (e.g., to support two-level memory data mapping decisions), advanced memory and interconnect features such as repair resources and routing tables, prefetching hints, error correcting code (ECC) bits, lists of device capabilities, set and store base address, capability, device ID, status, configuration, capabilities, and other settings.

In-memory interconnect protocol configuration registers

Science.gov (United States)

Cheng, Kevin Y.; Roberts, David A.

2017-09-19

Systems, apparatuses, and methods for moving the interconnect protocol configuration registers into the main memory space of a node. The region of memory used for storing the interconnect protocol configuration registers may also be made cacheable to reduce the latency of accesses to the interconnect protocol configuration registers. Interconnect protocol configuration registers which are used during a startup routine may be prefetched into the host's cache to make the startup routine more efficient. The interconnect protocol configuration registers for various interconnect protocols may include one or more of device capability tables, memory-side statistics (e.g., to support two-level memory data mapping decisions), advanced memory and interconnect features such as repair resources and routing tables, prefetching hints, error correcting code (ECC) bits, lists of device capabilities, set and store base address, capability, device ID, status, configuration, capabilities, and other settings.

An optimization framework for the integrated planning of generation and transmission expansion in interconnected power systems

International Nuclear Information System (INIS)

Guerra, Omar J.; Tejada, Diego A.; Reklaitis, Gintaras V.

2016-01-01

Highlights: • A novel optimization framework for the design and planning of interconnected power systems is proposed. • The framework integrates generation and transmission capacity expansion planning. • Reserve and emission constraints are included. • Business as usual and CO_2 mitigation policy scenarios are evaluated. • Reconfiguration of existing power generation technologies is the most cost-effective option for CO_2 emissions mitigation. - Abstract: Energy, and particularly electricity, has played and will continue to play a very important role in the development of human society. Electricity, which is the most flexible and manageable energy form, is currently used in a variety of activities and applications. For instance, electricity is used for heating, cooling, lighting, and for operating electronic appliances and electric vehicles. Nowadays, given the rapid development and commercialization of technologies and devices that rely on electricity, electricity demand is increasing faster than overall primary energy supply. Consequently, the design and planning of power systems is becoming a progressively more important issue in order to provide affordable, reliable and sustainable energy in timely fashion, not only in developed countries but particularly in developing economies where electricity demand is increasing even faster. Power systems are networks of electrical devices, such as power plants, transformers, and transmission lines, used to produce, transmit, and supply electricity. The design and planning of such systems require the selection of generation technologies, along with the capacity, location, and timing of generation and transmission capacity expansions to meet electricity demand over a long-term horizon. This manuscript presents a comprehensive optimization framework for the design and planning of interconnected power systems, including the integration of generation and transmission capacity expansion planning. The proposed

Load Frequency Control of AC Microgrid Interconnected Thermal Power System

Science.gov (United States)

Lal, Deepak Kumar; Barisal, Ajit Kumar

2017-08-01

In this paper, a microgrid (MG) power generation system is interconnected with a single area reheat thermal power system for load frequency control study. A new meta-heuristic optimization algorithm i.e. Moth-Flame Optimization (MFO) algorithm is applied to evaluate optimal gains of the fuzzy based proportional, integral and derivative (PID) controllers. The system dynamic performance is studied by comparing the results with MFO optimized classical PI/PID controllers. Also the system performance is investigated with fuzzy PID controller optimized by recently developed grey wolf optimizer (GWO) algorithm, which has proven its superiority over other previously developed algorithm in many interconnected power systems.

Experimental investigations of the minimum ignition energy and the minimum ignition temperature of inert and combustible dust cloud mixtures

Energy Technology Data Exchange (ETDEWEB)

Addai, Emmanuel Kwasi, E-mail: emmanueladdai41@yahoo.com; Gabel, Dieter; Krause, Ulrich

2016-04-15

Highlights: • Ignition sensitivity of a highly flammable dust decreases upon addition of inert dust. • Minimum ignition temperature of a highly flammable dust increases when inert concentration increase. • Minimum ignition energy of a highly flammable dust increases when inert concentration increase. • The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%. - Abstract: The risks associated with dust explosions still exist in industries that either process or handle combustible dust. This explosion risk could be prevented or mitigated by applying the principle of inherent safety (moderation). This is achieved by adding an inert material to a highly combustible material in order to decrease the ignition sensitivity of the combustible dust. The presented paper deals with the experimental investigation of the influence of adding an inert dust on the minimum ignition energy and the minimum ignition temperature of the combustible/inert dust mixtures. The experimental investigation was done in two laboratory scale equipment: the Hartmann apparatus and the Godbert-Greenwald furnace for the minimum ignition energy and the minimum ignition temperature test respectively. This was achieved by mixing various amounts of three inert materials (magnesium oxide, ammonium sulphate and sand) and six combustible dusts (brown coal, lycopodium, toner, niacin, corn starch and high density polyethylene). Generally, increasing the inert materials concentration increases the minimum ignition energy as well as the minimum ignition temperatures until a threshold is reached where no ignition was obtained. The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%.

Experimental investigations of the minimum ignition energy and the minimum ignition temperature of inert and combustible dust cloud mixtures

International Nuclear Information System (INIS)

Addai, Emmanuel Kwasi; Gabel, Dieter; Krause, Ulrich

2016-01-01

Highlights: • Ignition sensitivity of a highly flammable dust decreases upon addition of inert dust. • Minimum ignition temperature of a highly flammable dust increases when inert concentration increase. • Minimum ignition energy of a highly flammable dust increases when inert concentration increase. • The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%. - Abstract: The risks associated with dust explosions still exist in industries that either process or handle combustible dust. This explosion risk could be prevented or mitigated by applying the principle of inherent safety (moderation). This is achieved by adding an inert material to a highly combustible material in order to decrease the ignition sensitivity of the combustible dust. The presented paper deals with the experimental investigation of the influence of adding an inert dust on the minimum ignition energy and the minimum ignition temperature of the combustible/inert dust mixtures. The experimental investigation was done in two laboratory scale equipment: the Hartmann apparatus and the Godbert-Greenwald furnace for the minimum ignition energy and the minimum ignition temperature test respectively. This was achieved by mixing various amounts of three inert materials (magnesium oxide, ammonium sulphate and sand) and six combustible dusts (brown coal, lycopodium, toner, niacin, corn starch and high density polyethylene). Generally, increasing the inert materials concentration increases the minimum ignition energy as well as the minimum ignition temperatures until a threshold is reached where no ignition was obtained. The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%.

Development and testing of hydrogen ignition devices

International Nuclear Information System (INIS)

Renfro, D.; Smith, L.; Thompson, L.; Clever, R.

1982-01-01

Controlled ignition systems for the mitigation of hydrogen produced during degraded core accidents have been installed recently in several light water reactor (LWR) containments. This paper relates the background of the thermal igniter approach and its application to LWR controlled ignition systems. The process used by the Tennessee Valley Authority (TVA) to select a hydrogen mitigation system in general and an igniter type in particular is described. Descriptions of both the Interim Distributed Ignition System and the Permanent Hydrogen Mitigation System installed by TVA are included as examples. Testing of igniter durability at TVA's Singleton Materials Engineering Laboratory and of igniter performance at Atomic Energy of Canada's Whiteshell Nuclear Research Establishment is presented

Investigation and experimental validation of the contribution of optical interconnects in the SYMPHONIE massively parallel computer

International Nuclear Information System (INIS)

Scheer, Patrick

1998-01-01

Progress in microelectronics lead to electronic circuits which are increasingly integrated, with an operating frequency and an inputs/outputs count larger than the ones supported by printed circuit board and back-plane technologies. As a result, distributed systems with several boards cannot fully exploit the performance of integrated circuits. In synchronous parallel computers, the situation is worsen since the overall system performances rely on the efficiency of electrical interconnects between the integrated circuits which include the processing elements (PE). The study of a real parallel computer named SYMPHONIE shows for instance that the system operating frequency is far smaller than the capabilities of the microelectronics technology used for the PE implementation. Optical interconnections may cancel these limitations by providing more efficient connections between the PE. Especially, free-space optical interconnections based on vertical-cavity surface-emitting lasers (VCSEL), micro-lens and PIN photodiodes are compatible with the required features of the PE communications. Zero bias modulation of VCSEL with CMOS-compatible digital signals is studied and experimentally demonstrated. A model of the propagation of truncated gaussian beams through micro-lenses is developed. It is then used to optimise the geometry of the detection areas. A dedicated mechanical system is also proposed and implemented for integrating free-space optical interconnects in a standard electronic environment, representative of the one of parallel computer systems. A specially designed demonstrator provides the experimental validation of the above physical concepts. (author) [fr

Auto-Ignition and Spray Characteristics of n-Heptane and iso-Octane Fuels in Ignition Quality Tester

KAUST Repository

Jaasim, Mohammed

2018-04-04

Numerical simulations were conducted to systematically assess the effects of different spray models on the ignition delay predictions and compared with experimental measurements obtained at the KAUST ignition quality tester (IQT) facility. The influence of physical properties and chemical kinetics over the ignition delay time is also investigated. The IQT experiments provided the pressure traces as the main observables, which are not sufficient to obtain a detailed understanding of physical (breakup, evaporation) and chemical (reactivity) processes associated with auto-ignition. A three-dimensional computational fluid dynamics (CFD) code, CONVERGE™, was used to capture the detailed fluid/spray dynamics and chemical characteristics within the IQT configuration. The Reynolds-averaged Navier-Stokes (RANS) turbulence with multi-zone chemistry sub-models was adopted with a reduced chemical kinetic mechanism for n-heptane and iso-octane. The emphasis was on the assessment of two common spray breakup models, namely the Kelvin-Helmholtz/Rayleigh-Taylor (KH-RT) and linearized instability sheet atomization (LISA) models, in terms of their influence on auto-ignition predictions. Two spray models resulted in different local mixing, and their influence in the prediction of auto-ignition was investigated. The relative importance of physical ignition delay, characterized by spray evaporation and mixing processes, in the overall ignition behavior for the two different fuels were examined. The results provided an improved understanding of the essential contribution of physical and chemical processes that are critical in describing the IQT auto-ignition event at different pressure and temperature conditions, and allowed a systematic way to distinguish between the physical and chemical ignition delay times.

The volume ignition for ICF ignition target

International Nuclear Information System (INIS)

Li, Y. S.; He, X. T.; Yu, M.

1997-01-01

Compared with central model, volume ignition has no hot spot, avoids the mixing at the hot-cold interface, the α-particle escaping, and the high convergence, greatly reduces the sharp demanding for uniformity. In laser indirect driving, from theoretical estimation and computational simulation, we have proved that using a tamper with good heat resistance, the DT fuel can be ignited in LTE at ∼3 KeV and then evolves to the non-LTE ignition at >5 KeV. In this case, 1 MJ radiation energy in the hohlraum could cause near 10 MJ output for a pellet with 0.2 mg DT fuel. We have compared results with and without α-particle transport, it shows that in the condition of ρR>0.5 g/cm 2 of DT fuel, both have the same results. For the system with ρR≅0.5 g/cm 2 we can use α-particle local deposition scheme. The non-uniformly doped tamper with density ρ≅1-5 g/cc can reduce mixing due to the small convergence ratio. The input energy is deposited in DT and tamper during the implosion, we try to reduce the tamper energy by changing the ratio of CH and doped Au and the thickness of the tamper

Ignition inhibitors for cellulosic materials

International Nuclear Information System (INIS)

Alvares, N.J.

1976-01-01

By exposing samples to various irradiance levels from a calibrated thermal radiation source, the ignition responses of blackened alpha-cellulose and cotton cloth with and without fire-retardant additives were compared. Samples treated with retardant compounds which showed the most promise were then isothermally pyrolyzed in air for comparisons between the pyrolysis rates. Alpha-cellulose samples containing a mixture of boric acid, borax, and ammonium di-hydrogen phosphate could not be ignited by irradiances up to 4.0 cal cm -2 s-1 (16.7 W/cm 2 ). At higher irradiances the specimens ignited, but flaming lasted only until the flammable gases were depleted. Cotton cloth containing a polymeric retardant with the designation THPC + MM was found to be ignition-resistant to all irradiances below 7.0 cal cm -2 s -1 (29.3 W/cm 2 ). Comparison of the pyrolysis rates of the retardant-treated alpha-cellulose and the retardant-treated cotton showed that the retardant mechanism is qualitatively the same. Similar ignition-response measurements were also made with specimens exposed to ionizing radiation. It was observed that gamma radiation results in ignition retardance of cellulose, while irradiation by neutrons does not

Target design for shock ignition

International Nuclear Information System (INIS)

Schurtz, G; Ribeyre, X; Lafon, M

2010-01-01

The conventional approach of laser driven inertial fusion involves the implosion of cryogenic shells of deuterium-tritium ice. At sufficiently high implosion velocities, the fuel ignites by itself from a central hot spot. In order to reduce the risks of hydrodynamic instabilities inherent to large implosion velocities, it was proposed to compress the fuel at low velocity, and ignite the compressed fuel by means of a convergent shock wave driven by an intense spike at the end of the laser pulse. This scheme, known as shock ignition, reduces the risks of shell break-up during the acceleration phase, but it may be impeded by a low coupling efficiency of the laser pulse with plasma at high intensities. This work provides a relationship between the implosion velocity and the laser intensity required to ignite the target by a shock. The operating domain of shock ignition at different energies is described.

Understanding price discovery in interconnected markets: Generalized Langevin process approach and simulation

Science.gov (United States)

Schenck, Natalya A.; Horvath, Philip A.; Sinha, Amit K.

2018-02-01

While the literature on price discovery process and information flow between dominant and satellite market is exhaustive, most studies have applied an approach that can be traced back to Hasbrouck (1995) or Gonzalo and Granger (1995). In this paper, however, we propose a Generalized Langevin process with asymmetric double-well potential function, with co-integrated time series and interconnected diffusion processes to model the information flow and price discovery process in two, a dominant and a satellite, interconnected markets. A simulated illustration of the model is also provided.

Indirect-drive noncryogenic double-shell ignition targets for the National Ignition Facility: Design and analysis

International Nuclear Information System (INIS)

Amendt, Peter; Colvin, J.D.; Tipton, R.E.; Hinkel, D.E.; Edwards, M.J.; Landen, O.L.; Ramshaw, J.D.; Suter, L.J.; Varnum, W.S.; Watt, R.G.

2002-01-01

Analysis and design of indirect-drive National Ignition Facility double-shell targets with hohlraum temperatures of 200 eV and 250 eV are presented. The analysis of these targets includes the assessment of two-dimensional radiation asymmetry and nonlinear mix. Two-dimensional integrated hohlraum simulations indicate that the x-ray illumination can be adjusted to provide adequate symmetry control in hohlraums specially designed to have high laser-coupling efficiency [Suter et al., Phys. Plasmas 7, 2092 (2000)]. These simulations also reveal the need to diagnose and control localized 10-15 keV x-ray emission from the high-Z hohlraum wall because of strong absorption by the high-Z inner shell. Preliminary estimates of the degree of laser backscatter from an assortment of laser-plasma interactions suggest comparatively benign hohlraum conditions. The application of a variety of nonlinear mix models and phenomenological tools, including buoyancy-drag models, multimode simulations and fall-line optimization, indicates a possibility of achieving ignition, i.e., fusion yields greater than 1 MJ. Planned experiments on the Omega laser will test current understanding of high-energy radiation flux asymmetry and mix-induced yield degradation in double-shell targets

National Offshore Wind Energy Grid Interconnection Study

Energy Technology Data Exchange (ETDEWEB)

Daniel, John P. [ABB Inc; Liu, Shu [ABB Inc; Ibanez, Eduardo [National Renewable Energy Laboratory; Pennock, Ken [AWS Truepower; Reed, Greg [University of Pittsburgh; Hanes, Spencer [Duke Energy

2014-07-30

The National Offshore Wind Energy Grid Interconnection Study (NOWEGIS) considers the availability and potential impacts of interconnecting large amounts of offshore wind energy into the transmission system of the lower 48 contiguous United States. A total of 54GW of offshore wind was assumed to be the target for the analyses conducted. A variety of issues are considered including: the anticipated staging of offshore wind; the offshore wind resource availability; offshore wind energy power production profiles; offshore wind variability; present and potential technologies for collection and delivery of offshore wind energy to the onshore grid; potential impacts to existing utility systems most likely to receive large amounts of offshore wind; and regulatory influences on offshore wind development. The technologies considered the reliability of various high-voltage ac (HVAC) and high-voltage dc (HVDC) technology options and configurations. The utility system impacts of GW-scale integration of offshore wind are considered from an operational steady-state perspective and from a regional and national production cost perspective.

Heavy ion fusion targets; issues for fast ignition

International Nuclear Information System (INIS)

Bangerter, Roger O.

2014-01-01

During the last 36 years researchers have suggested and evaluated a large number of target designs for heavy ion inertial fusion. The different target designs can be classified according to their mode of ignition, their method of implosion, and their size. Ignition modes include hot-spot ignition and fast ignition. Methods of implosion include direct drive and indirect drive. Historically there has been significant work on indirectly driven targets with hot-spot ignition. Recently there has been increasing interest in directly driven targets with ion driven fast ignition. In principle, fast ignition might lead to improved target performance. On the other hand, fast ignition imposes stringent requirements on accelerators and beam physics. Furthermore, fast ignition magnifies the importance of a number of traditional target physics issues associated with ion beam energy deposition and fuel preheat. This paper will discuss the advantages and disadvantages of the various classes of targets. It will also discuss some issues that must be resolved to assess the feasibility of ion fast ignition

Evidence of Processing Non-Idealities in 4H-SiC Integrated Circuits Fabricated with Two Levels of Metal Interconnect

Science.gov (United States)

Spry, David J.; Neudeck, Philip G.; Liangyu, Chen; Evans, Laura J.; Lukco, Dorothy; Chang, Carl W.; Beheim, Glenn M.

2015-01-01

The fabrication and prolonged 500 C electrical testing of 4H-SiC junction field effect transistor (JFET) integrated circuits (ICs) with two levels of metal interconnect is reported in another submission to this conference proceedings. While some circuits functioned more than 1000 hours at 500 C, the majority of packaged ICs from this wafer electrically failed after less than 200 hours of operation in the same test conditions. This work examines the root physical degradation and failure mechanisms believed responsible for observed large discrepancies in 500 C operating time. Evidence is presented for four distinct issues that significantly impacted 500 C IC operational yield and lifetime for this wafer.

Ignition criterion for heterogeneous energetic materials based on hotspot size-temperature threshold

Science.gov (United States)

Barua, A.; Kim, S.; Horie, Y.; Zhou, M.

2013-02-01

A criterion for the ignition of granular explosives (GXs) and polymer-bonded explosives (PBXs) under shock and non-shock loading is developed. The formulation is based on integration of a quantification of the distributions of the sizes and locations of hotspots in loading events using a cohesive finite element method (CFEM) developed recently and the characterization by Tarver et al. [C. M. Tarver et al., "Critical conditions for impact- and shock-induced hot spots in solid explosives," J. Phys. Chem. 100, 5794-5799 (1996)] of the critical size-temperature threshold of hotspots required for chemical ignition of solid explosives. The criterion, along with the CFEM capability to quantify the thermal-mechanical behavior of GXs and PBXs, allows the critical impact velocity for ignition, time to ignition, and critical input energy at ignition to be determined as functions of material composition, microstructure, and loading conditions. The applicability of the relation between the critical input energy (E) and impact velocity of James [H. R. James, "An extension to the critical energy criterion used to predict shock initiation thresholds," Propellants, Explos., Pyrotech. 21, 8-13 (1996)] for shock loading is examined, leading to a modified interpretation, which is sensitive to microstructure and loading condition. As an application, numerical studies are undertaken to evaluate the ignition threshold of granular high melting point eXplosive, octahydro-1,3,5,7-tetranitro-1,2,3,5-tetrazocine (HMX) and HMX/Estane PBX under loading with impact velocities up to 350 ms-1 and strain rates up to 105 s-1. Results show that, for the GX, the time to criticality (tc) is strongly influenced by initial porosity, but is insensitive to grain size. Analyses also lead to a quantification of the differences between the responses of the GXs and PBXs in terms of critical impact velocity for ignition, time to ignition, and critical input energy at ignition. Since the framework permits

Fundamental Studies of Ignition Process in Large Natural Gas Engines Using Laser Spark Ignition

Energy Technology Data Exchange (ETDEWEB)

Azer Yalin; Bryan Willson

2008-06-30

Past research has shown that laser ignition provides a potential means to reduce emissions and improve engine efficiency of gas-fired engines to meet longer-term DOE ARES (Advanced Reciprocating Engine Systems) targets. Despite the potential advantages of laser ignition, the technology is not seeing practical or commercial use. A major impediment in this regard has been the 'open-path' beam delivery used in much of the past research. This mode of delivery is not considered industrially practical owing to safety factors, as well as susceptibility to vibrations, thermal effects etc. The overall goal of our project has been to develop technologies and approaches for practical laser ignition systems. To this end, we are pursuing fiber optically coupled laser ignition system and multiplexing methods for multiple cylinder engine operation. This report summarizes our progress in this regard. A partial summary of our progress includes: development of a figure of merit to guide fiber selection, identification of hollow-core fibers as a potential means of fiber delivery, demonstration of bench-top sparking through hollow-core fibers, single-cylinder engine operation with fiber delivered laser ignition, demonstration of bench-top multiplexing, dual-cylinder engine operation via multiplexed fiber delivered laser ignition, and sparking with fiber lasers. To the best of our knowledge, each of these accomplishments was a first.

Lubricant induced pre-ignition in an optical spark-ignition engine

OpenAIRE

Dingle, Simon Frederick

2014-01-01

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London This work focuses on the introduction of lubricant into the combustion chamber and the effect that this has on pre-ignition. Apparently for the first time, the work presented provides detailed full-bore optical data for lubricant induced pre-ignition and improves understanding of the super-knock phenomena that affects modern downsized gasoline engines. A new single-cylinder optical r...

Roll and pitch independently tuned interconnected suspension: modelling and dynamic analysis

Science.gov (United States)

Xu, Guangzhong; Zhang, Nong; Roser, Holger M.

2015-12-01

In this paper, a roll and pitch independently tuned hydraulically interconnected passive suspension is presented. Due to decoupling of vibration modes and the improved lateral and longitudinal stability, the stiffness of individual suspension spring can be reduced for improving ride comfort and road grip. A generalised 14 degree-of-freedom nonlinear vehicle model with anti-roll bars is established to investigate the vehicle ride and handling dynamic responses. The nonlinear fluidic model of the hydraulically interconnected suspension is developed and integrated with the full vehicle model to investigate the anti-roll and anti-pitch characteristics. Time domain analysis of the vehicle model with the proposed suspension is conducted under different road excitations and steering/braking manoeuvres. The dynamic responses are compared with conventional suspensions to demonstrate the potential of enhanced ride and handling performance. The results illustrate the model-decoupling property of the hydraulically interconnected system. The anti-roll and anti-pitch performance could be tuned independently by the interconnected systems. With the improved anti-roll and anti-pitch characteristics, the bounce stiffness and ride damping can be optimised for better ride comfort and tyre grip.

Benefit of regional energy balancing service on wind integration in the western interconnection of the United States

Energy Technology Data Exchange (ETDEWEB)

Milligan, Michael; Kirby, Brendan; King, Jack [National Renewable Energy Laboratory, Golden, CO (United States); Beuning, Stephen [Xcel Energy Inc., Minneapolis, MN (United States)

2010-07-01

Interest in various wide-area balancing schemes to help integrate wind have generated significant interest. As we have shown in past work, large balancing areas not only help with wind integration, but can also increase the efficiency of operations in systems without wind. Recent work on the Western Wind and Solar Integration Study (WWSIS) has found that combining balancing over the WestConnect footprint will increase the efficiency of commitment and dispatch at wind penetrations ranging from 10-30% of annual electricity demand, and will be essential for high penetrations and small balancing areas. In addition the northwest Wind Integration Action Plan recommended balancing area cooperation as a method to help integrate the large potential wind development. In this paper we investigate the potential impact of a proposed Energy Imbalance Service on the ability of the non-market portions of Western Electricity Coordinating Councils (WECC) United States footprint to integrate wind energy. We will utilize data adapted from the WWSIS for the Western Interconnection. The analysis uses time-synchronized wind and load data to evaluate the potential for ramp requirement reduction that could be achieved with combined operation. Chronological analysis and ramp duration analysis quantify the benefit in terms of not only the ramp sizes, but the frequency of the potentially avoided ramps that must be managed by the non-wind generation fleet. Multiple approaches that can be used to achieve these benefits are also suggested in the paper. We also suggest other approaches that can help achieve much of the benefit of full consolidation without requiring the physical consolidation of balancing areas. (orig.)

Plasma physics study and laser development for the fast ignition realization experiment (FIREX) project

International Nuclear Information System (INIS)

Azechi, H.; Mima, K.; Fujimoto, Y.

2008-10-01

Since the approval of the first phase of Fast Ignition Realization Experiment (FIREX-I), we have devoted our efforts on designing advanced targets and constructing the world highest-energy Peta Watt laser. The new target design has the following features. The coupling efficiency from the heating laser to the thermal energy of the compressed core plasma can be increased by the two ways:1) Low-Z foam layer on the inner surface of the cone for optimum absorption. 2) Double cone. Electrons generated in the inner surface of the double cone will return by sheathe potential generated between two cones. The implosion performance can be improved by three ways: 3) Low-Z plastic layer on the outer surface of the cone may suppress the expansion of the Au cone that flows into the interior of the compressed core. 4) Br doped plastic ablator may significantly moderate the Rayleigh-Taylor instability, making implosion more stable. 5) Evacuation of the target center to prevent gas jets from destroying the cone tip. For project robustness, we also explore 6) impact ignition scheme that eliminates complexity of laser-plasma interaction while keeping the compactness advantage of fast ignition. The fully integrated fast ignition experiment is scheduled on 2009. If subsequent FIREX-II will start as proposed, the ignition and burn will be demonstrated shortly after the ignition at NIF and LMJ, providing a scientific database of both central and fast ignition. (author)

Studies into laser ignition of confined pyrotechnics

Energy Technology Data Exchange (ETDEWEB)

Ahmad, S.R.; Russell, D.A. [Centre for Applied Laser Spectroscopy, DASSR, Defence Academy, Cranfield University, Shrivenham, Swindon (United Kingdom)

2008-10-15

Ignition tests were carried out on three different pyrotechnics using laser energy from the multimode output from an Ar-Ion laser (av) at 500 nm and a near-IR diode laser pigtailed to a fibre optic cable and operating at 808 nm. The pyrotechnics investigated were: G20 black powder, SR44 and SR371C. The confined ignition tests were conducted in a specially designed ignition chamber. Pyrotechnics were ignited by a free space beam entering the chamber through an industrial sapphire window in the case of the Ar-ion laser. For the NIR diode laser, fibre was ducted through a block into direct contact with the pyrotechnic. The Ar-Ion laser was chosen as this was found to ignite all three pyrotechnics in the unconfined condition. It also allowed for a direct comparison of confined/unconfined results to be made. The threshold laser flux densities to initiate reproducible ignitions at this wavelength were found to be between {proportional_to}12.7 and {proportional_to}0.16 kW cm{sup -2}. Plotted on the ignition maps are the laser flux densities versus the start of ignition times for the three confined pyrotechnics. It was found from these maps that the times for confined ignition were substantially lower than those obtained for unconfined ignition under similar experimental conditions. For the NIR diode laser flux densities varied between {proportional_to}6.8 and {proportional_to}0.2 kW cm{sup -2}. The minimum ignition times for the NIR diode laser for SR371C ({proportional_to}11.2 ms) and G20 ({proportional_to}17.1 ms) were faster than those achieved by the use of the Ar-ion laser. However, the minimum ignition time was shorter ({proportional_to}11.7 ms) with the Ar-ion laser for SR44. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

Relating the octane numbers of fuels to ignition delay times measured in an ignition quality tester (IQT)

KAUST Repository

Naser, Nimal; Yang, Seung Yeon; Kalghatgi, Gautam; Chung, Suk-Ho

2016-01-01

an ignition quality tester. A baseline data of ignition delay times were determined using an ignition quality tester at a charge pressure of 21.3 bar between 770 and 850 K and an equivalence ratio of 0.7 for various primary reference fuels (PRFs, mixtures

Central ignition scenarios for TFTR

International Nuclear Information System (INIS)

Zweben, S.J.; Redi, M.H.; Bateman, G.

1986-03-01

The possibility of obtaining ignition in TFTR by means of very centrally peaked density profiles is examined. It is shown that local central alpha heating can be made to exceed local central energy losses (''central ignition'') under global conditions for which Q greater than or equal to 1. Time dependent 1-D transport simulations show that the normal global ignition requirements are substantially relaxed for plasmas with peaked density profiles. 18 refs., 18 figs

Modelling piloted ignition of wood and plastics

International Nuclear Information System (INIS)

Blijderveen, Maarten van; Bramer, Eddy A.; Brem, Gerrit

2012-01-01

Highlights: ► We model piloted ignition times of wood and plastics. ► The model is applied on a packed bed. ► When the air flow is above a critical level, no ignition can take place. - Abstract: To gain insight in the startup of an incinerator, this article deals with piloted ignition. A newly developed model is described to predict the piloted ignition times of wood, PMMA and PVC. The model is based on the lower flammability limit and the adiabatic flame temperature at this limit. The incoming radiative heat flux, sample thickness and moisture content are some of the used variables. Not only the ignition time can be calculated with the model, but also the mass flux and surface temperature at ignition. The ignition times for softwoods and PMMA are mainly under-predicted. For hardwoods and PVC the predicted ignition times agree well with experimental results. Due to a significant scatter in the experimental data the mass flux and surface temperature calculated with the model are hard to validate. The model is applied on the startup of a municipal waste incineration plant. For this process a maximum allowable primary air flow is derived. When the primary air flow is above this maximum air flow, no ignition can be obtained.

Interconnecting Governments, Businesses and Citizens : A Comparison of Two Digital Infrastructures

NARCIS (Netherlands)

Klievink, A.J.; Zuiderwijk-van Eijk, A.M.G.; Janssen, M.F.W.H.A.

2014-01-01

Public and private organizations in various areas are setting up digital Information Infrastructures (IIs) for interconnecting government, businesses and citizens. IIs can create value by sharing and integrating data of multiple ac-tors. This can be the basis for value added services and especially

Improving student comprehension of the interconnectivity of the hydrologic cycle with a novel 'hydrology toolbox', integrated watershed model, and companion textbook

Science.gov (United States)

Huning, L. S.; Margulis, S. A.

2013-12-01

Concepts in introductory hydrology courses are often taught in the context of process-based modeling that ultimately is integrated into a watershed model. In an effort to reduce the learning curve associated with applying hydrologic concepts to real-world applications, we developed and incorporated a 'hydrology toolbox' that complements a new, companion textbook into introductory undergraduate hydrology courses. The hydrology toolbox contains the basic building blocks (functions coded in MATLAB) for an integrated spatially-distributed watershed model that makes hydrologic topics (e.g. precipitation, snow, radiation, evaporation, unsaturated flow, infiltration, groundwater, and runoff) more user-friendly and accessible for students. The toolbox functions can be used in a modular format so that students can study individual hydrologic processes and become familiar with the hydrology toolbox. This approach allows such courses to emphasize understanding and application of hydrologic concepts rather than computer coding or programming. While topics in introductory hydrology courses are often introduced and taught independently or semi-independently, they are inherently interconnected. These toolbox functions are therefore linked together at the end of the course to reinforce a holistic understanding of how these hydrologic processes are measured, interconnected, and modeled. They are integrated into a spatially-distributed watershed model or numerical laboratory where students can explore a range of topics such as rainfall-runoff modeling, urbanization, deforestation, watershed response to changes in parameters or forcings, etc. Model output can readily be visualized and analyzed by students to understand watershed response in a real river basin or a simple 'toy' basin. These tools complement the textbook, each of which has been well received by students in multiple hydrology courses with various disciplinary backgrounds. The same governing equations that students have

Policy issues in interconnecting networks

Science.gov (United States)

Leiner, Barry M.

1989-01-01

To support the activities of the Federal Research Coordinating Committee (FRICC) in creating an interconnected set of networks to serve the research community, two workshops were held to address the technical support of policy issues that arise when interconnecting such networks. The workshops addressed the required and feasible technologies and architectures that could be used to satisfy the desired policies for interconnection. The results of the workshop are documented.

Report from the Integrated Modeling Panel at the Workshop on the Science of Ignition on NIF

Energy Technology Data Exchange (ETDEWEB)

Marinak, M; Lamb, D

2012-07-03

This section deals with multiphysics radiation hydrodynamics codes used to design and simulate targets in the ignition campaign. These topics encompass all the physical processes they model, and include consideration of any approximations necessary due to finite computer resources. The section focuses on what developments would have the highest impact on reducing uncertainties in modeling most relevant to experimental observations. It considers how the ICF codes should be employed in the ignition campaign. This includes a consideration of how the experiments can be best structured to test the physical models the codes employ.

Experimental investigations of the minimum ignition energy and the minimum ignition temperature of inert and combustible dust cloud mixtures.

Science.gov (United States)

Addai, Emmanuel Kwasi; Gabel, Dieter; Krause, Ulrich

2016-04-15

The risks associated with dust explosions still exist in industries that either process or handle combustible dust. This explosion risk could be prevented or mitigated by applying the principle of inherent safety (moderation). This is achieved by adding an inert material to a highly combustible material in order to decrease the ignition sensitivity of the combustible dust. The presented paper deals with the experimental investigation of the influence of adding an inert dust on the minimum ignition energy and the minimum ignition temperature of the combustible/inert dust mixtures. The experimental investigation was done in two laboratory scale equipment: the Hartmann apparatus and the Godbert-Greenwald furnace for the minimum ignition energy and the minimum ignition temperature test respectively. This was achieved by mixing various amounts of three inert materials (magnesium oxide, ammonium sulphate and sand) and six combustible dusts (brown coal, lycopodium, toner, niacin, corn starch and high density polyethylene). Generally, increasing the inert materials concentration increases the minimum ignition energy as well as the minimum ignition temperatures until a threshold is reached where no ignition was obtained. The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%. Copyright © 2016 Elsevier B.V. All rights reserved.

Ignition of Cellulosic Paper at Low Radiant Fluxes

Science.gov (United States)

White, K. Alan

1996-01-01

The ignition of cellulosic paper by low level thermal radiation is investigated. Past work on radiative ignition of paper is briefly reviewed. No experimental study has been reported for radiative ignition of paper at irradiances below 10 Watts/sq.cm. An experimental study of radiative ignition of paper at these low irradiances is reported. Experimental parameters investigated and discussed include radiant power levels incident on the sample, the method of applying the radiation (focussed vs. diffuse Gaussian source), the presence and relative position of a separate pilot ignition source, and the effects of natural convection (buoyancy) on the ignition process in a normal gravity environment. It is observed that the incident radiative flux (in W/sq.cm) has the greatest influence on ignition time. For a given flux level, a focussed Gaussian source is found to be advantageous to a more diffuse, lower amplitude, thermal source. The precise positioning of a pilot igniter relative to gravity and to the fuel sample affects the ignition process, but the precise effects are not fully understood. Ignition was more readily achieved and sustained with a horizontal fuel sample, indicating the buoyancy plays a role in the ignition process of cellulosic paper. Smoldering combustion of doped paper samples was briefly investigated, and results are discussed.

Shock ignition targets: gain and robustness vs ignition threshold factor

Science.gov (United States)

Atzeni, Stefano; Antonelli, Luca; Schiavi, Angelo; Picone, Silvia; Volponi, Gian Marco; Marocchino, Alberto

2017-10-01

Shock ignition is a laser direct-drive inertial confinement fusion scheme, in which the stages of compression and hot spot formation are partly separated. The hot spot is created at the end of the implosion by a converging shock driven by a final ``spike'' of the laser pulse. Several shock-ignition target concepts have been proposed and relevant gain curves computed (see, e.g.). Here, we consider both pure-DT targets and more facility-relevant targets with plastic ablator. The investigation is conducted with 1D and 2D hydrodynamic simulations. We determine ignition threshold factors ITF's (and their dependence on laser pulse parameters) by means of 1D simulations. 2D simulations indicate that robustness to long-scale perturbations increases with ITF. Gain curves (gain vs laser energy), for different ITF's, are generated using 1D simulations. Work partially supported by Sapienza Project C26A15YTMA, Sapienza 2016 (n. 257584), Eurofusion Project AWP17-ENR-IFE-CEA-01.

14 CFR 33.69 - Ignitions system.

Science.gov (United States)

2010-01-01

... STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.69 Ignitions system. Each..., except that only one igniter is required for fuel burning augmentation systems. [Amdt. 33-6, 39 FR 35466... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ignitions system. 33.69 Section 33.69...

Physical studies of fast ignition in China

International Nuclear Information System (INIS)

He, X T; Cai, Hong-bo; Wu, Si-zhong; Cao, Li-hua; Zhang, Hua; He, Ming-qing; Chen, Mo; Wu, Jun-feng; Zhou, Cang-tao; Zhou, Wei-Min; Shan, Lian-qiang; Wang, Wei-wu; Zhang, Feng; Bi, Bi; Zhao, Zong-qing; Gu, Yu-qiu; Zhang, Bao-han; Wang, Wei; Fang, Zhi-heng; Lei, An-le

2015-01-01

Fast ignition approach to inertial confinement fusion is one of the important goals today, in addition to central hot spot ignition in China. The SG-IIU and PW laser facilities are coupled to investigate the hot spot formation for fast ignition. The SG-III laser facility is almost completed and will be coupled with tens kJ PW lasers for the demonstration of fast ignition. In recent years, for physical studies of fast ignition, we have been focusing on the experimental study of implosion symmetry, M-band radiation preheating and mixing, advanced fast ignition target design, and so on. In addition, the modeling capabilities and code developments enhanced our ability to perform the hydro-simulation of the compression implosion, and the particle-in-cell (PIC) and hybrid-PIC simulation of the generation, transport and deposition of relativistic electron beams. Considerable progress has been achieved in understanding the critical issues of fast ignition. (paper)

HIGH-RESOLUTION SIMULATIONS OF CONVECTION PRECEDING IGNITION IN TYPE Ia SUPERNOVAE USING ADAPTIVE MESH REFINEMENT

International Nuclear Information System (INIS)

Nonaka, A.; Aspden, A. J.; Almgren, A. S.; Bell, J. B.; Zingale, M.; Woosley, S. E.

2012-01-01

We extend our previous three-dimensional, full-star simulations of the final hours of convection preceding ignition in Type Ia supernovae to higher resolution using the adaptive mesh refinement capability of our low Mach number code, MAESTRO. We report the statistics of the ignition of the first flame at an effective 4.34 km resolution and general flow field properties at an effective 2.17 km resolution. We find that off-center ignition is likely, with radius of 50 km most favored and a likely range of 40-75 km. This is consistent with our previous coarser (8.68 km resolution) simulations, implying that we have achieved sufficient resolution in our determination of likely ignition radii. The dynamics of the last few hot spots preceding ignition suggest that a multiple ignition scenario is not likely. With improved resolution, we can more clearly see the general flow pattern in the convective region, characterized by a strong outward plume with a lower speed recirculation. We show that the convective core is turbulent with a Kolmogorov spectrum and has a lower turbulent intensity and larger integral length scale than previously thought (on the order of 16 km s –1 and 200 km, respectively), and we discuss the potential consequences for the first flames.

Hot-wire ignition of AN-based emulsions

Energy Technology Data Exchange (ETDEWEB)

Turcotte, Richard; Goldthorp, Sandra; Badeen, Christopher M. [Canadian Explosives Research Laboratory, Natural Resources Canada, Ottawa, Ontario, K1A 0G1 (Canada); Chan, Sek Kwan [Orica Canada Inc., Brownsburg-Chatham, Quebec (Canada)

2008-12-15

Emulsions based on ammonium nitrate (AN) and water locally ignited by a heat source do not undergo sustained combustion when the pressure is lower than some threshold value usually called the Minimum Burning Pressure (MBP). This concept is now being used by some manufacturers as a basis of safety. However, before a technique to reliably measure MBP values can be designed, one must have a better understanding of the ignition mechanism. Clearly, this is required to avoid under ignitions which could lead to the erroneous interpretation of failures to ignite as failures to propagate. In the present work, facilities to prepare and characterize emulsions were implemented at the Canadian Explosives Research Laboratory. A calibrated hot-wire ignition system operated in a high-pressure vessel was also built. The system was used to study the ignition characteristics of five emulsion formulations as a function of pressure and ignition source current. It was found that these mixtures exhibit complicated pre-ignition stages and that the appearance of endotherms when the pressure is lowered below some threshold value correlates with the MBP. Thermal conductivity measurements using this hot-wire system are also reported. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

18 CFR 292.306 - Interconnection costs.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Interconnection costs... § 292.306 Interconnection costs. (a) Obligation to pay. Each qualifying facility shall be obligated to pay any interconnection costs which the State regulatory authority (with respect to any electric...

Relating the octane numbers of fuels to ignition delay times measured in an ignition quality tester (IQT)

KAUST Repository

Naser, Nimal

2016-09-21

A methodology for estimating the octane index (OI), the research octane number (RON) and the motor octane number (MON) using ignition delay times from a constant volume combustion chamber with liquid fuel injection is proposed by adopting an ignition quality tester. A baseline data of ignition delay times were determined using an ignition quality tester at a charge pressure of 21.3 bar between 770 and 850 K and an equivalence ratio of 0.7 for various primary reference fuels (PRFs, mixtures of isooctane and n-heptane). Our methodology was developed using ignition delay times for toluene reference fuels (mixtures of toluene and n-heptane). A correlation between the OI and the ignition delay time at the initial charge temperature enabled the OI of non-PRFs to be predicted at specified temperatures. The methodology was validated using ignition delay times for toluene primary reference fuels (ternary mixtures of toluene, iso-octane, and n-heptane), fuels for advanced combustion engines (FACE) gasolines, and certification gasolines. Using this methodology, the RON, the MON, and the octane sensitivity were estimated in agreement with values obtained from standard test methods. A correlation between derived cetane number and RON is also provided. (C) 2016 Elsevier Ltd. All rights reserved.

Decentralised output feedback control of Markovian jump interconnected systems with unknown interconnections

Science.gov (United States)

Li, Li-Wei; Yang, Guang-Hong

2017-07-01

The problem of decentralised output feedback control is addressed for Markovian jump interconnected systems with unknown interconnections and general transition rates (TRs) allowed to be unknown or known with uncertainties. A class of decentralised dynamic output feedback controllers are constructed, and a cyclic-small-gain condition is exploited to dispose the unknown interconnections so that the resultant closed-loop system is stochastically stable and satisfies an H∞ performance. With slack matrices to cope with the nonlinearities incurred by unknown and uncertain TRs in control synthesis, a novel controller design condition is developed in linear matrix inequality formalism. Compared with the existing works, the proposed approach leads to less conservatism. Finally, two examples are used to illustrate the effectiveness of the new results.

Desensitizing nano powders to electrostatic discharge ignition

International Nuclear Information System (INIS)

Steelman, Ryan; Daniels, Michael A.

2015-01-01

Electrostatic discharge (ESD) is a main cause for ignition in powder media ranging from grain silos to fireworks. Nanoscale particles are orders of magnitude more ESD ignition sensitive than their micron scale counterparts. This study shows that at least 13 vol. % carbon nanotubes (CNT) added to nano-aluminum and nano-copper oxide particles (nAl + CuO) eliminates ESD ignition sensitivity. The CNT act as a conduit for electric energy and directs electric charge through the powder to desensitize the reactive mixture to ignition. For nanoparticles, the required CNT concentration for desensitizing ESD ignition acts as a diluent to quench energy propagation.

Structure ignition assessment model (SIAM)\\t

Science.gov (United States)

Jack D. Cohen

1995-01-01

Major wildland/urban interface fire losses, principally residences, continue to occur. Although the problem is not new, the specific mechanisms are not well known on how structures ignite in association with wildland fires. In response to the need for a better understanding of wildland/urban interface ignition mechanisms and a method of assessing the ignition risk,...

Ignition circuit for combustion engines

Energy Technology Data Exchange (ETDEWEB)

Becker, H W

1977-05-26

The invention refers to the ignition circuit for combustion engines, which are battery fed. The circuit contains a transistor and an oscillator to produce an output voltage on the secondary winding of an output transformer to supply an ignition current. The plant is controlled by an interrupter. The purpose of the invention is to form such a circuit that improved sparks for ignition are produced, on the one hand, and that on the other hand, the plant can continue to function after loss of the oscillator. The problem is solved by the battery and the secondary winding of the output transformers of the oscillator are connected via a rectifier circuit to produce a resultant total voltage with the ignition coil from the battery voltage and the rectified pulsating oscillator output.

The IGNITE network: a model for genomic medicine implementation and research.

Science.gov (United States)

Weitzel, Kristin Wiisanen; Alexander, Madeline; Bernhardt, Barbara A; Calman, Neil; Carey, David J; Cavallari, Larisa H; Field, Julie R; Hauser, Diane; Junkins, Heather A; Levin, Phillip A; Levy, Kenneth; Madden, Ebony B; Manolio, Teri A; Odgis, Jacqueline; Orlando, Lori A; Pyeritz, Reed; Wu, R Ryanne; Shuldiner, Alan R; Bottinger, Erwin P; Denny, Joshua C; Dexter, Paul R; Flockhart, David A; Horowitz, Carol R; Johnson, Julie A; Kimmel, Stephen E; Levy, Mia A; Pollin, Toni I; Ginsburg, Geoffrey S

2016-01-05

Patients, clinicians, researchers and payers are seeking to understand the value of using genomic information (as reflected by genotyping, sequencing, family history or other data) to inform clinical decision-making. However, challenges exist to widespread clinical implementation of genomic medicine, a prerequisite for developing evidence of its real-world utility. To address these challenges, the National Institutes of Health-funded IGNITE (Implementing GeNomics In pracTicE; www.ignite-genomics.org ) Network, comprised of six projects and a coordinating center, was established in 2013 to support the development, investigation and dissemination of genomic medicine practice models that seamlessly integrate genomic data into the electronic health record and that deploy tools for point of care decision making. IGNITE site projects are aligned in their purpose of testing these models, but individual projects vary in scope and design, including exploring genetic markers for disease risk prediction and prevention, developing tools for using family history data, incorporating pharmacogenomic data into clinical care, refining disease diagnosis using sequence-based mutation discovery, and creating novel educational approaches. This paper describes the IGNITE Network and member projects, including network structure, collaborative initiatives, clinical decision support strategies, methods for return of genomic test results, and educational initiatives for patients and providers. Clinical and outcomes data from individual sites and network-wide projects are anticipated to begin being published over the next few years. The IGNITE Network is an innovative series of projects and pilot demonstrations aiming to enhance translation of validated actionable genomic information into clinical settings and develop and use measures of outcome in response to genome-based clinical interventions using a pragmatic framework to provide early data and proofs of concept on the utility of these

Surface breakdown igniter for mercury arc devices

Science.gov (United States)

Bayless, John R.

1977-01-01

Surface breakdown igniter comprises a semiconductor of medium resistivity which has the arc device cathode as one electrode and has an igniter anode electrode so that when voltage is applied between the electrodes a spark is generated when electrical breakdown occurs over the surface of the semiconductor. The geometry of the igniter anode and cathode electrodes causes the igniter discharge to be forced away from the semiconductor surface.

Strategic Environmental Assessment: a case study of interconnected 500 kV Italy-France

International Nuclear Information System (INIS)

Viola, S.; Ceccariglia, M.; Rivabene, N.; Motawi, A.

2007-01-01

For the new interconnected power transmission line Italy-France is applied the Strategic Environmental Assessment procedure for the purpose of integration planning electric and railway lines of the new base tunnel Lyon Turin Ferroviaire Frejus [it

Design of a deuterium and tritium-ablator shock ignition target for the National Ignition Facility

International Nuclear Information System (INIS)

Terry, Matthew R.; Perkins, L. John; Sepke, Scott M.

2012-01-01

Shock ignition presents a viable path to ignition and high gain on the National Ignition Facility (NIF). In this paper, we describe the development of the 1D design of 0.5 MJ class, all-deuterium and tritium (fuel and ablator) shock ignition target that should be reasonably robust to Rayleigh-Taylor fluid instabilities, mistiming, and hot electron preheat. The target assumes “day one” NIF hardware and produces a yield of 31 MJ with reasonable allowances for laser backscatter, absorption efficiency, and polar drive power variation. The energetics of polar drive laser absorption require a beam configuration with half of the NIF quads dedicated to launching the ignitor shock, while the remaining quads drive the target compression. Hydrodynamic scaling of the target suggests that gains of 75 and yields 70 MJ may be possible.

Physical characteristics of welding arc ignition process

Science.gov (United States)

Shi, Linan; Song, Yonglun; Xiao, Tianjiao; Ran, Guowei

2012-07-01

The existing research of welding arc mainly focuses on the stable combustion state and the research on the mechanism of welding arc ignition process is quite lack. The tungsten inert gas(TIG) touch arc ignition process is observed via a high speed camera and the high time resolution spectral diagnosis system. The changing phenomenon of main ionized element provided the electrons in the arc ignition is found. The metallic element is the main contributor to provide the electrons at the beginning of the discharging, and then the excitated shielding gas element replaces the function of the metallic element. The electron density during the period of the arc ignition is calculated by the Stark-broadened lines of Hα. Through the discussion with the repeatability in relaxation phenomenon, the statistical regularity in the arc ignition process is analyzed. The similar rules as above are observed through the comparison with the laser-assisted arc ignition experiments and the metal inert gas(MIG) arc ignition experiments. This research is helpful to further understanding on the generation mechanism of welding arc ignition and also has a certain academic and practical significance on enriching the welding physical theoretical foundation and improving the precise monitoring on automatic arc welding process.

Understanding Biomass Ignition in Power Plant Mills

DEFF Research Database (Denmark)

Schwarzer, Lars; Jensen, Peter Arendt; Glarborg, Peter

2017-01-01

. This is not very well explained by apply-ing conventional thermal ignition theory. An experimental study at lab scale, using pinewood as an example fuel, was conducted to examine self-heating and self-ignition. Supplemental experiments were performed with bituminous coal. Instead of characterizing ignition......Converting existing coal fired power plants to biomass is a readily implemented strategy to increase the share of renewable energy. However, changing from one fuel to another is not straightforward: Experience shows that wood pellets ignite more readily than coal in power plant mills or storages...... temperature in terms of sample volume, mass-scaling seems more physically correct for the self-ignition of solids. Findings also suggest that the transition between self-heating and self-ignition is controlled both by the availability of reactive material and temperature. Comparison of experiments at 20...

Laser Ignition Microthruster Experiments on KKS-1

Science.gov (United States)

Nakano, Masakatsu; Koizumi, Hiroyuki; Watanabe, Masashi; Arakawa, Yoshihiro

A laser ignition microthruster has been developed for microsatellites. Thruster performances such as impulse and ignition probability were measured, using boron potassium nitrate (B/KNO3) solid propellant ignited by a 1 W CW laser diode. The measured impulses were 60 mNs ± 15 mNs with almost 100 % ignition probability. The effect of the mixture ratios of B/KNO3 on thruster performance was also investigated, and it was shown that mixture ratios between B/KNO3/binder = 28/70/2 and 38/60/2 exhibited both high ignition probability and high impulse. Laser ignition thrusters designed and fabricated based on these data became the first non-conventional microthrusters on the Kouku Kousen Satellite No. 1 (KKS-1) microsatellite that was launched by a H2A rocket as one of six piggyback satellites in January 2009.

Fuel cell system with interconnect

Science.gov (United States)

Goettler, Richard; Liu, Zhien

2017-12-12

The present invention includes a fuel cell system having a plurality of adjacent electrochemical cells formed of an anode layer, a cathode layer spaced apart from the anode layer, and an electrolyte layer disposed between the anode layer and the cathode layer. The fuel cell system also includes at least one interconnect, the interconnect being structured to conduct free electrons between adjacent electrochemical cells. Each interconnect includes a primary conductor embedded within the electrolyte layer and structured to conduct the free electrons.

Development status of the ignition system for Vinci

NARCIS (Netherlands)

Frenken, G.; Vermeulen, E.; Bouquet, F.; Sanders, H.M.

2002-01-01

The development status of ignition system for the new cryogenic upper stage engine Vinci is presented. The concept differs from existing upper stage ignition systems as its functioning is engine independent. The system consists of a spark torch igniter, a highpressure igniter feed system and an

The physics basis for ignition using indirect-drive targets on the National Ignition Facility

International Nuclear Information System (INIS)

Lindl, John D.; Amendt, Peter; Berger, Richard L.; Glendinning, S. Gail; Glenzer, Siegfried H.; Haan, Steven W.; Kauffman, Robert L.; Landen, Otto L.; Suter, Laurence J.

2004-01-01

The 1990 National Academy of Science final report of its review of the Inertial Confinement Fusion Program recommended completion of a series of target physics objectives on the 10-beam Nova laser at the Lawrence Livermore National Laboratory as the highest-priority prerequisite for proceeding with construction of an ignition-scale laser facility, now called the National Ignition Facility (NIF). These objectives were chosen to demonstrate that there was sufficient understanding of the physics of ignition targets that the laser requirements for laboratory ignition could be accurately specified. This research on Nova, as well as additional research on the Omega laser at the University of Rochester, is the subject of this review. The objectives of the U.S. indirect-drive target physics program have been to experimentally demonstrate and predictively model hohlraum characteristics, as well as capsule performance in targets that have been scaled in key physics variables from NIF targets. To address the hohlraum and hydrodynamic constraints on indirect-drive ignition, the target physics program was divided into the Hohlraum and Laser-Plasma Physics (HLP) program and the Hydrodynamically Equivalent Physics (HEP) program. The HLP program addresses laser-plasma coupling, x-ray generation and transport, and the development of energy-efficient hohlraums that provide the appropriate spectral, temporal, and spatial x-ray drive. The HEP experiments address the issues of hydrodynamic instability and mix, as well as the effects of flux asymmetry on capsules that are scaled as closely as possible to ignition capsules (hydrodynamic equivalence). The HEP program also addresses other capsule physics issues associated with ignition, such as energy gain and energy loss to the fuel during implosion in the absence of alpha-particle deposition. The results from the Nova and Omega experiments approach the NIF requirements for most of the important ignition capsule parameters, including

Eddy current measurement of the thickness of top Cu film of the multilayer interconnects in the integrated circuit (IC) manufacturing process

Science.gov (United States)

Qu, Zilian; Meng, Yonggang; Zhao, Qian

2015-03-01

This paper proposes a new eddy current method, named equivalent unit method (EUM), for the thickness measurement of the top copper film of multilayer interconnects in the chemical mechanical polishing (CMP) process, which is an important step in the integrated circuit (IC) manufacturing. The influence of the underneath circuit layers on the eddy current is modeled and treated as an equivalent film thickness. By subtracting this equivalent film component, the accuracy of the thickness measurement of the top copper layer with an eddy current sensor is improved and the absolute error is 3 nm for sampler measurement.

The US ICF Ignition Program and the Inertial Fusion Program

International Nuclear Information System (INIS)

Lindl, J D; Hammel, B A; Logan, B G; Meyerhofer, D D; Payne, S A; Stehian, J D

2003-01-01

There has been rapid progress in inertial fusion in the past few years. This progress spans the construction of ignition facilities, a wide range of target concepts, and the pursuit of integrated programs to develop fusion energy using lasers, ion beams and z-pinches. Two ignition facilities are under construction (NIF in the U.S. and LMJ in France) and both projects are progressing toward an initial experimental capability. The LIL prototype beamline for LMJ and the first 4 beams of NIF will be available for experiments in 2003. The full 192 beam capability of NIF will be available in 2009 and ignition experiments are expected to begin shortly after that time. There is steady progress in the target science and target fabrication in preparation for indirect drive ignition experiments on NIF. Advanced target designs may lead to 5-10 times more yield than initial target designs. There has also been excellent progress on the science of ion beam and z-pinch driven indirect drive targets. Excellent progress on direct-drive targets has been obtained on the Omega laser at the University of Rochester. This includes improved performance of targets with a pulse shape predicted to result in reduced hydrodynamic instability. Rochester has also obtained encouraging results from initial cryogenic implosions. There is widespread interest in the science of fast ignition because of its potential for achieving higher target gain with lower driver energy and relaxed target fabrication requirements. Researchers from Osaka have achieved outstanding implosion and heating results from the Gekko XII Petawatt facility and implosions suitable for fast ignition have been tested on the Omega laser. A broad based program to develop lasers and ions beams for IFE is under way with excellent progress in drivers, chambers, target fabrication and target injection. KrF and Diode Pumped Solid-State lasers (DPSSL) are being developed in conjunction with drywall chambers and direct drive targets

Developing the Physics Basis of Fast Ignition Experiments at Future Large Fusion-class lasers

International Nuclear Information System (INIS)

Mackinnon, A J; Key, M H; Hatchett, S; MacPhee, A G; Foord, M; Tabak, M; Town, R J; Patel, P K

2008-01-01

The Fast Ignition (FI) concept for Inertial Confinement Fusion (ICF) has the potential to provide a significant advance in the technical attractiveness of Inertial Fusion Energy (IFE) reactors. FI differs from conventional 'central hot spot' (CHS) target ignition by using one driver (laser, heavy ion beam or Z-pinch) to create a dense fuel and a separate ultra-short, ultra-intense laser beam to ignite the dense core. FI targets can burn with ∼ 3X lower density fuel than CHS targets, resulting in (all other things being equal) lower required compression energy, relaxed drive symmetry, relaxed target smoothness tolerances, and, importantly, higher gain. The short, intense ignition pulse that drives this process interacts with extremely high energy density plasmas; the physics that controls this interaction is only now becoming accessible in the lab, and is still not well understood. The attraction of obtaining higher gains in smaller facilities has led to a worldwide explosion of effort in the studies of FI. In particular, two new US facilities to be completed in 2009/2010, OMEGA/OMEGA EP and NIF-ARC (as well as others overseas) will include FI investigations as part of their program. These new facilities will be able to approach FI conditions much more closely than heretofore using direct drive (dd) for OMEGA/OMEGA EP and indirect drive (id) for NIF-ARC. This LDRD has provided the physics basis for the development of the detailed design for integrated Fast ignition experiments on these facilities on the 2010/2011 timescale. A strategic initiative LDRD has now been formed to carry out integrated experiments using NIF ARC beams to heat a full scale FI assembled core by the end of 2010

Ion beam heating for fast ignition

International Nuclear Information System (INIS)

Gus'kov, S.Yu.; Limpouch, J.; Klimo, O.

2010-01-01

Complete text of publication follows. The characteristics features of the formation of the spatial distribution of the energy transferred to the plasma from a beam of ions with different initial energies, masses and charges under fast ignition conditions are determined. The motion of the Bragg peak is extended with respect to the spatial distribution of the temperature of the ion-beam-heated medium. The parameters of the ion beams are determined to initiate different regimes of fast ignition of thermonuclear fuel precompressed to a density of 300-500 g/cm 3 - the edge regime, in which the ignition region is formed at the outer boundary of the fuel, and the internal regime, in which the ignition region is formed in central parts of the fuel. The conclusion on the requirements for fast ignition by light and heavy ion beams is presented. It is shown that the edge heating with negative temperature gradient is described by a self-similar solution. Such a temperature distribution is the reason of the fact that the ignited beam energy at the edge heating is larger than the minimal ignition energy by factor 1.65. The temperature Bragg peak may be produced by ion beam heating in the reactor scale targets with pR-parameter larger than 3-4 g/cm 2 . In particular, for central ignition of the targets with pR-parameters in the range of 4-8 g/cm 2 the ion beam energy should be, respectively, from 5 to 7 times larger than the minimal ignition energy. The work by S.Ye. Gus'kov, D.V. Il'in, and V.E. Sherman was supported by the Ministry of Education and Science of the Russian Federation under the program 'Development of the Scientific Potential of High Education for 2009-2010' (project no. 2.1.1/1505) and the Russian Foundation for Basic Research (project no. 08-02-01394 a ). The work by J. Limpouch and O. Klimo was supported by the Czech Ministry of Education (project no. LC528, MSM6840770022).

Renewable Electricity-to-Grid Integration | Energy Systems Integration

Science.gov (United States)

Facility | NREL Renewable Electricity-to-Grid Integration Renewable Electricity-to-Grid Integration NREL works with industry partners to optimize strategies for effectively interconnecting renewable renewable electric grid integration work includes research and development (R&D) on advanced inverters

11.72 sq cm SiC Wafer-scale Interconnected 64 kA PiN Diode

Science.gov (United States)

2012-01-30

drop of 10.3 V. The dissipated energy was 382 J and the calculated action exceeded 1.7 MA2 -s. Preliminary development of high voltage interconnection...scale diode action (surge current integral), a key reliability parameter, exceeded 1.7 MA2 -s. Figure 6: The wafer-scale interconnected diode...scale diode was 382 J and the calculated action exceeded 1.7 MA2 -sec. High voltage operation of PiN diodes, thyristors, and other semiconductor

EXPERIMENTS AND COMPUTATIONAL MODELING OF PULVERIZED-COAL IGNITION; FINAL

International Nuclear Information System (INIS)

Samuel Owusu-Ofori; John C. Chen

1999-01-01

Under typical conditions of pulverized-coal combustion, which is characterized by fine particles heated at very high rates, there is currently a lack of certainty regarding the ignition mechanism of bituminous and lower rank coals as well as the ignition rate of reaction. furthermore, there have been no previous studies aimed at examining these factors under various experimental conditions, such as particle size, oxygen concentration, and heating rate. Finally, there is a need to improve current mathematical models of ignition to realistically and accurately depict the particle-to-particle variations that exist within a coal sample. Such a model is needed to extract useful reaction parameters from ignition studies, and to interpret ignition data in a more meaningful way. The authors propose to examine fundamental aspects of coal ignition through (1) experiments to determine the ignition temperature of various coals by direct measurement, and (2) modeling of the ignition process to derive rate constants and to provide a more insightful interpretation of data from ignition experiments. The authors propose to use a novel laser-based ignition experiment to achieve their first objective. Laser-ignition experiments offer the distinct advantage of easy optical access to the particles because of the absence of a furnace or radiating walls, and thus permit direct observation and particle temperature measurement. The ignition temperature of different coals under various experimental conditions can therefore be easily determined by direct measurement using two-color pyrometry. The ignition rate-constants, when the ignition occurs heterogeneously, and the particle heating rates will both be determined from analyses based on these measurements

Definition of Ignition in Inertial Confinement Fusion

Science.gov (United States)

Christopherson, A. R.; Betti, R.

2017-10-01

Defining ignition in inertial confinement fusion (ICF) is an unresolved problem. In ICF, a distinction must be made between the ignition of the hot spot and the propagation of the burn wave in the surrounding dense fuel. Burn propagation requires that the hot spot is robustly ignited and the dense shell exhibits enough areal density. Since most of the energy gain comes from burning the dense shell, in a scale of increasing yields, hot-spot ignition comes before high gains. Identifying this transition from hot-spot ignition to burn-wave propagation is key to defining ignition in general terms applicable to all fusion approaches that use solid DT fuel. Ad hoc definitions such as gain = 1 or doubling the temperature are not generally valid. In this work, we show that it is possible to identify the onset of ignition through a unique value of the yield amplification defined as the ratio of the fusion yield including alpha-particle deposition to the fusion yield without alphas. Since the yield amplification is a function of the fractional alpha energy fα =EαEα 2Ehs 2Ehs (a measurable quantity), it appears possible not only to define ignition but also to measure the onset of ignition by the experimental inference of the fractional alpha energy and yield amplification. This material is based upon work supported by the Department of Energy Office of Fusion Energy Services under Award Number DE-FC02-04ER54789 and National Nuclear Security Administration under Award Number DE-NA0001944.

Measuring the electrical resistivity and contact resistance of vertical carbon nanotube bundles for application as interconnects

International Nuclear Information System (INIS)

Chiodarelli, Nicolo'; Li, Yunlong; Arstila, Kai; Richard, Olivier; Cott, Daire J; Heyns, Marc; De Gendt, Stefan; Groeseneken, Guido; Vereecken, Philippe M; Masahito, Sugiura; Kashiwagi, Yusaku

2011-01-01

Carbon nanotubes (CNT) are known to be materials with potential for manufacturing sub-20 nm high aspect ratio vertical interconnects in future microchips. In order to be successful with respect to contending against established tungsten or copper based interconnects, though, CNT must fulfil their promise of also providing low electrical resistance in integrated structures using scalable integration processes fully compatible with silicon technology. Hence, carefully engineered growth and integration solutions are required before we can fully exploit their potentialities. This work tackles the problem of optimizing a CNT integration process from the electrical perspective. The technique of measuring the CNT resistance as a function of the CNT length is here extended to CNT integrated in vertical contacts. This allows extracting the linear resistivity and the contact resistance of the CNT, two parameters to our knowledge never reported separately for vertical CNT contacts and which are of utmost importance, as they respectively measure the quality of the CNT and that of their metal contacts. The technique proposed allows electrically distinguishing the impact of each processing step individually on the CNT resistivity and the CNT contact resistance. Hence it constitutes a powerful technique for optimizing the process and developing CNT contacts of superior quality. This can be of relevant technological importance not only for interconnects but also for all those applications that rely on the electrical properties of CNT grown with a catalytic chemical vapor deposition method at low temperature.

Study of ignition in a high compression ratio SI (spark ignition) methanol engine using LES (large eddy simulation) with detailed chemical kinetics

International Nuclear Information System (INIS)

Zhen, Xudong; Wang, Yang

2013-01-01

Methanol has been recently used as an alternative to conventional fuels for internal combustion engines in order to satisfy some environmental and economical concerns. In this paper, the ignition in a high compression ratio SI (spark ignition) methanol engine was studied by using LES (large eddy simulation) with detailed chemical kinetics. A 21-species, 84-reaction methanol mechanism was adopted to simulate the auto-ignition process of the methanol/air mixture. The MIT (minimum ignition temperature) and MIE (minimum ignition energy) are two important properties for designing safety standards and understanding the ignition process of combustible mixtures. The effects of the flame kernel size, flame kernel temperature and equivalence ratio were also examined on MIT, MIE and IDP (ignition delay period). The methanol mechanism was validated by experimental test. The simulated results showed that the flame kernel size, temperature and energy dramatically affected the values of the MIT, MIE and IDP for a methanol/air mixture, the value of the ignition delay period was not only related to the flame kernel energy, but also to the flame kernel temperature. - Highlights: • We used LES (large eddy simulation) coupled with detailed chemical kinetics to simulate methanol ignition. • The flame kernel size and temperature affected the minimum ignition temperature. • The flame kernel temperature and energy affected the ignition delay period. • The equivalence ratio of methanol–air mixture affected the ignition delay period

A sustained-arc ignition system for internal combustion engines

Science.gov (United States)

Birchenough, A. G.

1977-01-01

A sustained-arc ignition system was developed for internal combustion engines. It produces a very-long-duration ignition pulse with an energy in the order of 100 millijoules. The ignition pulse waveform can be controlled to predetermined actual ignition requirements. The design of the sustained-arc ignition system is presented in the report.

Enhancing Ignition Probability and Fusion Yield in NIF Indirect Drive Targets with Applied Magnetic Fields

Science.gov (United States)

Perkins, L. John; Logan, B. Grant; Ho, Darwin; Zimmerman, George; Rhodes, Mark; Blackfield, Donald; Hawkins, Steven

2017-10-01

Imposed magnetic fields of tens of Tesla that increase to greater than 10 kT (100 MGauss) under capsule compression may relax conditions for ignition and propagating burn in indirect-drive ICF targets. This may allow attainment of ignition, or at least significant fusion energy yields, in presently-performing ICF targets on the National Ignition Facility that today are sub-marginal for thermonuclear burn through adverse hydrodynamic conditions at stagnation. Results of detailed 2D radiation-hydrodynamic-burn simulations applied to NIF capsule implosions with low-mode shape perturbations and residual kinetic energy loss indicate that such compressed fields may increase the probability for ignition through range reduction of fusion alpha particles, suppression of electron heat conduction and stabilization of higher-mode RT instabilities. Optimum initial applied fields are around 50 T. Off-line testing has been performed of a hohlraum coil and pulsed power supply that could be integrated on NIF; axial fields of 58T were obtained. Given the full plasma structure at capsule stagnation may be governed by 3-D resistive MHD, the formation of closed magnetic field lines might further augment ignition prospects. Experiments are now required to assess the potential of applied magnetic fields to NIF ICF ignition and burn. Work performed under auspices of U.S. DOE by LLNL under Contract DE-AC52-07NA27344.

Variation Tolerant On-Chip Interconnects

CERN Document Server

Nigussie, Ethiopia Enideg

2012-01-01

This book presents design techniques, analysis and implementation of high performance and power efficient, variation tolerant on-chip interconnects.  Given the design paradigm shift to multi-core, interconnect-centric designs and the increase in sources of variability and their impact in sub-100nm technologies, this book will be an invaluable reference for anyone concerned with the design of next generation, high-performance electronics systems. Provides comprehensive, circuit-level explanation of high-performance, energy-efficient, variation-tolerant on-chip interconnect; Describes design techniques to mitigate problems caused by variation; Includes techniques for design and implementation of self-timed on-chip interconnect, delay variation insensitive communication protocols, high speed signaling techniques and circuits, bit-width independent completion detection and process, voltage and temperature variation tolerance.                          

Universal Interconnection Technology Workshop Proceedings

Energy Technology Data Exchange (ETDEWEB)

Sheaffer, P.; Lemar, P.; Honton, E. J.; Kime, E.; Friedman, N. R.; Kroposki, B.; Galdo, J.

2002-10-01

The Universal Interconnection Technology (UIT) Workshop - sponsored by the U.S. Department of Energy, Distributed Energy and Electric Reliability (DEER) Program, and Distribution and Interconnection R&D - was held July 25-26, 2002, in Chicago, Ill., to: (1) Examine the need for a modular universal interconnection technology; (2) Identify UIT functional and technical requirements; (3) Assess the feasibility of and potential roadblocks to UIT; (4) Create an action plan for UIT development. These proceedings begin with an overview of the workshop. The body of the proceedings provides a series of industry representative-prepared papers on UIT functions and features, present interconnection technology, approaches to modularization and expandability, and technical issues in UIT development as well as detailed summaries of group discussions. Presentations, a list of participants, a copy of the agenda, and contact information are provided in the appendices of this document.

Chemical Kinetics of Hydrocarbon Ignition in Practical Combustion Systems

International Nuclear Information System (INIS)

Westbrook, C.K.

2000-01-01

Chemical kinetic factors of hydrocarbon oxidation are examined in a variety of ignition problems. Ignition is related to the presence of a dominant chain branching reaction mechanism that can drive a chemical system to completion in a very short period of time. Ignition in laboratory environments is studied for problems including shock tubes and rapid compression machines. Modeling of the laboratory systems are used to develop kinetic models that can be used to analyze ignition in practical systems. Two major chain branching regimes are identified, one consisting of high temperature ignition with a chain branching reaction mechanism based on the reaction between atomic hydrogen with molecular oxygen, and the second based on an intermediate temperature thermal decomposition of hydrogen peroxide. Kinetic models are then used to describe ignition in practical combustion environments, including detonations and pulse combustors for high temperature ignition, and engine knock and diesel ignition for intermediate temperature ignition. The final example of ignition in a practical environment is homogeneous charge, compression ignition (HCCI) which is shown to be a problem dominated by the kinetics intermediate temperature hydrocarbon ignition. Model results show why high hydrocarbon and CO emissions are inevitable in HCCI combustion. The conclusion of this study is that the kinetics of hydrocarbon ignition are actually quite simple, since only one or two elementary reactions are dominant. However, there are many combustion factors that can influence these two major reactions, and these are the features that vary from one practical system to another

Ignition and spread of electrical wire fires

OpenAIRE

Huang, Xinyan

2012-01-01

Ignition of electrical wires by external heating is investigated in order to gain a better understanding of the initiation of electrical-wire fires. An ignition-to- spread model is developed to systematically explain ignition and the following transition to spread. The model predicts that for a higher-conductance wire it is more difficult to achieve ignition and the weak flame may extinguish during the transition phase because of a large conductive heat loss along the wire core. Wires with tw...

The US inertial confinement fusion (ICF) ignition programme and the inertial fusion energy (IFE) programme

Science.gov (United States)

Lindl, J. D.; Hammel, B. A.; Logan, B. Grant; Meyerhofer, David D.; Payne, S. A.; Sethian, John D.

2003-12-01

There has been rapid progress in inertial fusion in the past few years. This progress spans the construction of ignition facilities, a wide range of target concepts and the pursuit of integrated programmes to develop fusion energy using lasers, ion beams and z-pinches. Two ignition facilities are under construction, the national ignition facility (NIF) in the United States and the laser megajoule (LMJ) in France, and both projects are progressing towards an initial experimental capability. The laser integration line prototype beamline for LMJ and the first four beams of NIF will be available for experiments in 2003. The full 192 beam capability of NIF will be available in 2009 and ignition experiments are expected to begin shortly after that time. There is steady progress in target science and target fabrication in preparation for indirect-drive ignition experiments on NIF. Advanced target designs may lead to 5 10 times more yield than initial target designs. There has also been excellent progress on the science of ion beam and z-pinch-driven indirect-drive targets. Excellent progress on direct-drive targets has been obtained on the Omega laser at the University of Rochester. This includes improved performance of targets with a pulse shape predicted to result in reduced hydrodynamic instability. Rochester has also obtained encouraging results from initial cryogenic implosions. There is widespread interest in the science of fast ignition because of its potential for achieving higher target gain with lower driver energy and relaxed target fabrication requirements. Researchers from Osaka have achieved outstanding implosion and heating results from the Gekko XII Petawatt facility and implosions suitable for fast ignition have been tested on the Omega laser. A broad-based programme to develop lasers and ion beams for inertial fusion energy (IFE) is under way with excellent progress in drivers, chambers, target fabrication and target injection. KrF and diode pumped solid

The US inertial confinement fusion (ICF) ignition programme and the inertial fusion energy (IFE) programme

International Nuclear Information System (INIS)

Lindl, J D; Hammel, B A; Logan, B Grant; Meyerhofer, David D; Payne, S A; Sethian, John D

2003-01-01

There has been rapid progress in inertial fusion in the past few years. This progress spans the construction of ignition facilities, a wide range of target concepts and the pursuit of integrated programmes to develop fusion energy using lasers, ion beams and z-pinches. Two ignition facilities are under construction, the national ignition facility (NIF) in the United States and the laser megajoule (LMJ) in France, and both projects are progressing towards an initial experimental capability. The laser integration line prototype beamline for LMJ and the first four beams of NIF will be available for experiments in 2003. The full 192 beam capability of NIF will be available in 2009 and ignition experiments are expected to begin shortly after that time. There is steady progress in target science and target fabrication in preparation for indirect-drive ignition experiments on NIF. Advanced target designs may lead to 5-10 times more yield than initial target designs. There has also been excellent progress on the science of ion beam and z-pinch-driven indirect-drive targets. Excellent progress on direct-drive targets has been obtained on the Omega laser at the University of Rochester. This includes improved performance of targets with a pulse shape predicted to result in reduced hydrodynamic instability. Rochester has also obtained encouraging results from initial cryogenic implosions. There is widespread interest in the science of fast ignition because of its potential for achieving higher target gain with lower driver energy and relaxed target fabrication requirements. Researchers from Osaka have achieved outstanding implosion and heating results from the Gekko XII Petawatt facility and implosions suitable for fast ignition have been tested on the Omega laser. A broad-based programme to develop lasers and ion beams for inertial fusion energy (IFE) is under way with excellent progress in drivers, chambers, target fabrication and target injection. KrF and diode pumped solid

Thermo-mechanical properties and integrity of metallic interconnects in microelectronics

Science.gov (United States)

Ege, Efe Sinan

In this dissertation, combined numerical (Finite Element Method) and experimental efforts were undertaken to study thermo-mechanical behavior in microelectronic devices. Interconnects, including chip-level metallization and package-level solder joints, are used to join many of the circuit parts in modern equipment. The dissertation is structured into six independent studies after the introductory chapter. The first two studies focus on thermo-mechanical fatigue of solder joints. Thermo-mechanical fatigue, in the form of damage along a microstructurally coarsened region in tin-lead solder, is analyzed along with the effects of intermetallic morphology. Also, lap-shear testing is modeled to characterize the joint and to investigate the validity of experimental data from different solder and substrate geometries. In the third study, the effects of pre-machined holes on strain localization and overall ductility in bulk eutectic tin-lead alloy is examined. Finite element analyses, taking into account the viscoplastic response, were carried out to provide a mechanistic rationale to corroborate the experimental findings. The fourth study concerns chip-level copper interconnects. Various combinations of oxide and polymer-based low-k dielectric schemes, with and without the thin barrier layers surrounding the Cu line, are considered. Attention is devoted to the thermal stress and strain fields and their dependency on material properties, geometry, and modeling details. This study is followed by a chapter on atomistics of interface-mediated plasticity in thin metallic films. The objective is to gain fundamental insight into the underlying mechanisms affecting the mechanical response of nanoscale thin films. The final study investigates the effect of microstructural heterogeneity on indentation response, for the purpose of raising awareness of the uncertainties involved in applying indentation techniques in probing mechanical properties of miniaturized devices.

Electronic ignition system for internal combustion engines

Energy Technology Data Exchange (ETDEWEB)

Crowder, L W

1980-11-20

Mechanical ignition adjustment devices are sensitive to many effects, for example breakage, faults due to manufacturing tolerances, play in the linkage and the effect of a dirty or corrosive environment. It is therefore the purpose of the invention to provide an electronic ignition system which avoids the disadvantages of a mechanical system. The invention provides adjustment of the ignition point, which gives advance of the ignition timing with increasing speed. An output signal is formed, which supersedes the signal supplied by the electronic control system, so that the ignition is advanced. This also occurs with a larger crankshaft angle before top dead centre of the engine. The electronic control system combines with a source of AC time signals which has a generator as electrical transmitter and a DC battery and ignition coil. The rotor of the electrical generator is driven synchronised with the engine. Structural and functional details of the transistor control circuits are given in 5 patent claims.

Low power interconnect design

CERN Document Server

Saini, Sandeep

2015-01-01

This book provides practical solutions for delay and power reduction for on-chip interconnects and buses.  It provides an in depth description of the problem of signal delay and extra power consumption, possible solutions for delay and glitch removal, while considering the power reduction of the total system.  Coverage focuses on use of the Schmitt Trigger as an alternative approach to buffer insertion for delay and power reduction in VLSI interconnects. In the last section of the book, various bus coding techniques are discussed to minimize delay and power in address and data buses.   ·         Provides practical solutions for delay and power reduction for on-chip interconnects and buses; ·         Focuses on Deep Sub micron technology devices and interconnects; ·         Offers in depth analysis of delay, including details regarding crosstalk and parasitics;  ·         Describes use of the Schmitt Trigger as a versatile alternative approach to buffer insertion for del...

Ignition of mercury-free high intensity discharge lamps

International Nuclear Information System (INIS)

Czichy, M; Mentel, J; Awakowicz, P; Hartmann, T

2008-01-01

To achieve a better understanding of the ignition behaviour of D4 lamps for automotive headlights the ignition of mercury-free metal iodide test lamps characterized by a high xenon pressure, a small electrode distance and small electrode-wall distances is investigated. The ignition of these lamps is dominated by a high voltage requirement. Nevertheless lamps are found that show a surprisingly low ignition voltage. Electrical measurements and simultaneous optical observations of the ultra-fast streamer processes show that the breakdown takes place in two different modes. One of the ignition modes which requires a high ignition voltage is characterized by a breakdown in the volume between the electrode tips. The other mode is characterized by streamer discharges along the wall. In this case the cathode, its base and the wall around is involved in the ignition process and the lamp breaks down at low voltages

Epidemics spreading in interconnected complex networks

International Nuclear Information System (INIS)

Wang, Y.; Xiao, G.

2012-01-01

We study epidemic spreading in two interconnected complex networks. It is found that in our model the epidemic threshold of the interconnected network is always lower than that in any of the two component networks. Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. Theoretical analysis and simulation results show that, generally speaking, the epidemic size is not significantly affected by the inter-network correlation. In interdependent networks which can be viewed as a special case of interconnected networks, however, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant. -- Highlights: ► We study epidemic spreading in two interconnected complex networks. ► The epidemic threshold is lower than that in any of the two networks. And Interconnection correlation has impacts on threshold and average outbreak size. ► Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. ► We demonstrated and proved that Interconnection correlation does not affect epidemic size significantly. ► In interdependent networks, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant.

Epidemics spreading in interconnected complex networks

Energy Technology Data Exchange (ETDEWEB)

Wang, Y. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Institute of High Performance Computing, Agency for Science, Technology and Research (A-STAR), Singapore 138632 (Singapore); Xiao, G., E-mail: egxxiao@ntu.edu.sg [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

2012-09-03

We study epidemic spreading in two interconnected complex networks. It is found that in our model the epidemic threshold of the interconnected network is always lower than that in any of the two component networks. Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. Theoretical analysis and simulation results show that, generally speaking, the epidemic size is not significantly affected by the inter-network correlation. In interdependent networks which can be viewed as a special case of interconnected networks, however, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant. -- Highlights: ► We study epidemic spreading in two interconnected complex networks. ► The epidemic threshold is lower than that in any of the two networks. And Interconnection correlation has impacts on threshold and average outbreak size. ► Detailed theoretical analysis is proposed which allows quick and accurate calculations of epidemic threshold and average outbreak/epidemic size. ► We demonstrated and proved that Interconnection correlation does not affect epidemic size significantly. ► In interdependent networks, impacts of inter-network correlation on the epidemic threshold and outbreak size are more significant.

CWDM for very-short-reach and optical-backplane interconnections

Science.gov (United States)

Laha, Michael J.

2002-06-01

Course Wavelength Division Multiplexing (CWDM) provides access to next generation optical interconnect data rates by utilizing conventional electro-optical components that are widely available in the market today. This is achieved through the use of CWDM multiplexers and demultiplexers that integrate commodity type active components, lasers and photodiodes, into small optical subassemblies. In contrast to dense wavelength division multiplexing (DWDM), in which multiple serial data streams are combined to create aggregate data pipes perhaps 100s of gigabits wide, CWDM uses multiple laser sources contained in one module to create a serial equivalent data stream. For example, four 2.5 Gb/s lasers are multiplexed to create a 10 Gb/s data pipe. The advantages of CWDM over traditional serial optical interconnects include lower module power consumption, smaller packaging, and a superior electrical interface. This discussion will detail the concept of CWDM and design parameters that are considered when productizing a CWDM module into an industry standard optical interconnect. Additionally, a scalable parallel CWDM hybrid architecture will be described that allows the transport of large amounts of data from rack to rack in an economical fashion. This particular solution is targeted at solving optical backplane bottleneck problems predicted for the next generation terabit and petabit routers.

Proton Fast Ignition

International Nuclear Information System (INIS)

Key, M H; Freeman, R R; Hatchett, S P; MacKinnon, A J; Patel, P K; Snavely, R A; Stephens, R B

2006-04-01

Fast ignition (FI) by a laser generated ballistically focused proton beam is a more recently proposed alternative to the original concept of FI by a laser generated beam of relativistic electrons. It has potential advantages in less complex energy transport into dense plasma. Recent successful target heating experiments motivate further investigation of the feasibility of proton fast ignition. The concept, the physics and characteristics of the proton beams, the recent experimental work on focusing of the beams and heating of solid targets and the overall prospects for proton FI are discussed

Use of the target diagnostic control system in the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Shelton, R; Lagin, L; Nelson, J

2011-07-25

The extreme physics of targets shocked by NIF's 192-beam laser are observed by a diverse suite of diagnostics including optical backscatter, time-integrated, time resolved and gated X-ray sensors, laser velocity interferometry, and neutron time of flight. Diagnostics to diagnose fusion ignition implosion and neutron emissions have been developed. A Diagnostic Control System (DCS) for both hardware and software facilitates development and eases integration. Each complex diagnostic typically uses an ensemble of electronic instruments attached to sensors, digitizers, cameras, and other devices. In the DCS architecture each instrument is interfaced to a low-cost Window XP processor and Java application. Instruments are aggregated as needed in the supervisory system to form an integrated diagnostic. The Java framework provides data management, control services and operator GUI generation. During the past several years, over thirty-six diagnostics have been deployed using this architecture in support of the National Ignition Campaign (NIC). The DCS architecture facilitates the expected additions and upgrades to diagnostics as more experiments are performed. This paper presents the DCS architecture, framework and our experiences in using it during the NIC to operate, upgrade and maintain a large set of diagnostic instruments.

Use of the target diagnostic control system in the National Ignition Facility

International Nuclear Information System (INIS)

Shelton, R.; Lagin, L.; Nelson, J.

2011-01-01

The extreme physics of targets shocked by NIF's 192-beam laser are observed by a diverse suite of diagnostics including optical backscatter, time-integrated, time resolved and gated X-ray sensors, laser velocity interferometry, and neutron time of flight. Diagnostics to diagnose fusion ignition implosion and neutron emissions have been developed. A Diagnostic Control System (DCS) for both hardware and software facilitates development and eases integration. Each complex diagnostic typically uses an ensemble of electronic instruments attached to sensors, digitizers, cameras, and other devices. In the DCS architecture each instrument is interfaced to a low-cost Window XP processor and Java application. Instruments are aggregated as needed in the supervisory system to form an integrated diagnostic. The Java framework provides data management, control services and operator GUI generation. During the past several years, over thirty-six diagnostics have been deployed using this architecture in support of the National Ignition Campaign (NIC). The DCS architecture facilitates the expected additions and upgrades to diagnostics as more experiments are performed. This paper presents the DCS architecture, framework and our experiences in using it during the NIC to operate, upgrade and maintain a large set of diagnostic instruments.

Finite-Time Stability of Large-Scale Systems with Interval Time-Varying Delay in Interconnection

Directory of Open Access Journals (Sweden)

T. La-inchua

2017-01-01

Full Text Available We investigate finite-time stability of a class of nonlinear large-scale systems with interval time-varying delays in interconnection. Time-delay functions are continuous but not necessarily differentiable. Based on Lyapunov stability theory and new integral bounding technique, finite-time stability of large-scale systems with interval time-varying delays in interconnection is derived. The finite-time stability criteria are delays-dependent and are given in terms of linear matrix inequalities which can be solved by various available algorithms. Numerical examples are given to illustrate effectiveness of the proposed method.

Comprehensive evaluation of global energy interconnection development index

Science.gov (United States)

Liu, Lin; Zhang, Yi

2018-04-01

Under the background of building global energy interconnection and realizing green and low-carbon development, this article constructed the global energy interconnection development index system which based on the current situation of global energy interconnection development. Through using the entropy method for the weight analysis of global energy interconnection development index, and then using gray correlation method to analyze the selected countries, this article got the global energy interconnection development index ranking and level classification.

Short-wavelength and three-dimensional instability evolution in National Ignition Facility ignition capsule designs

International Nuclear Information System (INIS)

Clark, D. S.; Haan, S. W.; Cook, A. W.; Edwards, M. J.; Hammel, B. A.; Koning, J. M.; Marinak, M. M.

2011-01-01

Ignition capsule designs for the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)] have continued to evolve in light of improved physical data inputs, improving simulation techniques, and, most recently, experimental data from a growing number of NIF sub-ignition experiments. This paper summarizes a number of recent changes to the cryogenic capsule design and some of our latest techniques in simulating its performance. Specifically, recent experimental results indicated harder x-ray drive spectra in NIF hohlraums than were predicted and used in previous capsule optimization studies. To accommodate this harder drive spectrum, a series of high-resolution 2-D simulations, resolving Legendre mode numbers as high as 2000, were run and the germanium dopant concentration and ablator shell thicknesses re-optimized accordingly. Simultaneously, the possibility of cooperative or nonlinear interaction between neighboring ablator surface defects has motivated a series of fully 3-D simulations run with the massively parallel HYDRA code. These last simulations include perturbations seeded on all capsule interfaces and can use actual measured shell surfaces as initial conditions. 3-D simulations resolving Legendre modes up to 200 on large capsule sectors have run through ignition and burn, and higher resolution simulations resolving as high as mode 1200 have been run to benchmark high-resolution 2-D runs. Finally, highly resolved 3-D simulations have also been run of the jet-type perturbation caused by the fill tube fitted to the capsule. These 3-D simulations compare well with the more typical 2-D simulations used in assessing the fill tube's impact on ignition. Coupled with the latest experimental inputs from NIF, our improving simulation capability yields a fuller and more accurate picture of NIF ignition capsule performance.

Electron Shock Ignition of Inertial Fusion Targets

International Nuclear Information System (INIS)

Shang, W. L.; Betti, R.; Hu, S. X.; Woo, K.; Hao, L.

2017-01-01

Here, it is shown that inertial fusion targets designed with low implosion velocities can be shock ignited using laser–plasma interaction generated hot electrons (hot-e) to obtain high-energy gains. These designs are robust to multimode asymmetries and are predicted to ignite even for significantly distorted implosions. Electron shock ignition requires tens of kilojoules of hot-e, which can only be produced on a large laser facility like the National Ignition Facility, with the laser to hot-e conversion efficiency greater than 10% at laser intensities ~10 16 W/cm 2 .

Development of a pre-ignition submodel for hydrogen engines

Energy Technology Data Exchange (ETDEWEB)

Al-Baghdadi, Sadiq [University of Babylon (Iraq). Dept. of Mechanical Engineering

2005-10-15

In hydrogen-fuelled spark ignition engine applications, the onset of pre-ignition remains one of the prime limitations that needs to be addressed to avoid its incidence and achieve superior performance. This paper describes a new pre-ignition submodel for engine modelling codes. The effects of changes in key operating variables, such as compression ratio, spark timing, intake pressure, and temperature on pre-ignition limiting equivalence ratios are established both analytically and experimentally. With the established pre-ignition model, it is possible not only to investigate whether pre-ignition is observed with changing operating and design parameters, but also to evaluate those parameters' effects on the maximum possible pre-ignition intensity. (author)

3rd Conference on Ignition Systems for Gasoline Engines

CERN Document Server

Sens, Marc

2017-01-01

The volume includes selected and reviewed papers from the 3rd Conference on Ignition Systems for Gasoline Engines in Berlin in November 2016. Experts from industry and universities discuss in their papers the challenges to ignition systems in providing reliable, precise ignition in the light of a wide spread in mixture quality, high exhaust gas recirculation rates and high cylinder pressures. Classic spark plug ignition as well as alternative ignition systems are assessed, the ignition system being one of the key technologies to further optimizing the gasoline engine.

Interconnect fatigue design for terrestrial photovoltaic modules

Science.gov (United States)

Mon, G. R.; Moore, D. M.; Ross, R. G., Jr.

1982-03-01

The results of comprehensive investigation of interconnect fatigue that has led to the definition of useful reliability-design and life-prediction algorithms are presented. Experimental data indicate that the classical strain-cycle (fatigue) curve for the interconnect material is a good model of mean interconnect fatigue performance, but it fails to account for the broad statistical scatter, which is critical to reliability prediction. To fill this shortcoming the classical fatigue curve is combined with experimental cumulative interconnect failure rate data to yield statistical fatigue curves (having failure probability as a parameter) which enable (1) the prediction of cumulative interconnect failures during the design life of an array field, and (2) the unambiguous--ie., quantitative--interpretation of data from field-service qualification (accelerated thermal cycling) tests. Optimal interconnect cost-reliability design algorithms are derived based on minimizing the cost of energy over the design life of the array field.

Recent Development of SOFC Metallic Interconnect

Energy Technology Data Exchange (ETDEWEB)

Wu JW, Liu XB

2010-04-01

Interest in solid oxide fuel cells (SOFC) stems from their higher e±ciencies and lower levels of emitted pollu- tants, compared to traditional power production methods. Interconnects are a critical part in SOFC stacks, which connect cells in series electrically, and also separate air or oxygen at the cathode side from fuel at the anode side. Therefore, the requirements of interconnects are the most demanding, i:e:, to maintain high elec- trical conductivity, good stability in both reducing and oxidizing atmospheres, and close coe±cient of thermal expansion (CTE) match and good compatibility with other SOFC ceramic components. The paper reviewed the interconnect materials, and coatings for metallic interconnect materials.

The Advances, Challenges and Future Possibilities of Millimeter-Wave Chip-to-Chip Interconnections for Multi-Chip Systems

Directory of Open Access Journals (Sweden)

Amlan Ganguly

2018-02-01

Full Text Available With aggressive scaling of device geometries, density of manufacturing faults is expected to increase. Therefore, yield of complex Multi-Processor Systems-on-Chips (MP-SoCs will decrease due to higher probability of manufacturing defects especially, in dies with large area. Therefore, disintegration of large SoCs into smaller chips called chiplets will improve yield and cost of complex platform-based systems. This will also provide functional flexibility, modular scalability as well as the capability to integrate heterogeneous architectures and technologies in a single unit. However, with scaling of the number of chiplets in such a system, the shared resources in the system such as the interconnection fabric and memory modules will become performance bottlenecks. Additionally, the integration of heterogeneous chiplets operating at different frequencies and voltages can be challenging. State-of-the-art inter-chip communication requires power-hungry high-speed I/O circuits and data transfer over long wired traces on substrates. This increases energy consumption and latency while decreasing data bandwidth for chip-to-chip communication. In this paper, we explore the advances and the challenges of interconnecting a multi-chip system with millimeter-wave (mm-wave wireless interconnects from a variety of perspectives spanning multiple aspects of the wireless interconnection design. Our discussion on the recent advances include aspects such as interconnection topology, physical layer, Medium Access Control (MAC and routing protocols. We also present some potential paradigm-shifting applications as well as complementary technologies of wireless inter-chip communications.

Low energy routing platforms for optical interconnects using active plasmonics integrated with Silicon Photonics

DEFF Research Database (Denmark)

Vyrsokinos, K.; Papaioannou, S.; Kalavrouziotis, D.

2013-01-01

technologies to cope with the massive amount of data moving across all hierarchical communication levels, namely rack-to-rack, backplane, chip-to-chip and even on-chip interconnections. Plasmonics comes indeed as a disruptive technology that enables seamless interoperability between light beams and electronic...

Theory of hydro-equivalent ignition for inertial fusion and its applications to OMEGA and the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Nora, R.; Betti, R.; Bose, A.; Woo, K. M.; Christopherson, A. R.; Meyerhofer, D. D. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Fusion Science Center, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Physics and/or Mechanical Engineering, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Anderson, K. S.; Shvydky, A.; Marozas, J. A.; Collins, T. J. B.; Radha, P. B.; Hu, S. X.; Epstein, R.; Marshall, F. J.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); McCrory, R. L. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Department of Physics and/or Mechanical Engineering, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)

2014-05-15

The theory of ignition for inertial confinement fusion capsules [R. Betti et al., Phys. Plasmas 17, 058102 (2010)] is used to assess the performance requirements for cryogenic implosion experiments on the Omega Laser Facility. The theory of hydrodynamic similarity is developed in both one and two dimensions and tested using multimode hydrodynamic simulations with the hydrocode DRACO [P. B. Radha et al., Phys. Plasmas 12, 032702 (2005)] of hydro-equivalent implosions (implosions with the same implosion velocity, adiabat, and laser intensity). The theory is used to scale the performance of direct-drive OMEGA implosions to the National Ignition Facility (NIF) energy scales and determine the requirements for demonstrating hydro-equivalent ignition on OMEGA. Hydro-equivalent ignition on OMEGA is represented by a cryogenic implosion that would scale to ignition on the NIF at 1.8 MJ of laser energy symmetrically illuminating the target. It is found that a reasonable combination of neutron yield and areal density for OMEGA hydro-equivalent ignition is 3 to 6 × 10{sup 13} and ∼0.3 g/cm{sup 2}, respectively, depending on the level of laser imprinting. This performance has not yet been achieved on OMEGA.

Theory of hydro-equivalent ignition for inertial fusion and its applications to OMEGA and the National Ignition Facility

International Nuclear Information System (INIS)

Nora, R.; Betti, R.; Bose, A.; Woo, K. M.; Christopherson, A. R.; Meyerhofer, D. D.; Anderson, K. S.; Shvydky, A.; Marozas, J. A.; Collins, T. J. B.; Radha, P. B.; Hu, S. X.; Epstein, R.; Marshall, F. J.; Sangster, T. C.; McCrory, R. L.

2014-01-01

The theory of ignition for inertial confinement fusion capsules [R. Betti et al., Phys. Plasmas 17, 058102 (2010)] is used to assess the performance requirements for cryogenic implosion experiments on the Omega Laser Facility. The theory of hydrodynamic similarity is developed in both one and two dimensions and tested using multimode hydrodynamic simulations with the hydrocode DRACO [P. B. Radha et al., Phys. Plasmas 12, 032702 (2005)] of hydro-equivalent implosions (implosions with the same implosion velocity, adiabat, and laser intensity). The theory is used to scale the performance of direct-drive OMEGA implosions to the National Ignition Facility (NIF) energy scales and determine the requirements for demonstrating hydro-equivalent ignition on OMEGA. Hydro-equivalent ignition on OMEGA is represented by a cryogenic implosion that would scale to ignition on the NIF at 1.8 MJ of laser energy symmetrically illuminating the target. It is found that a reasonable combination of neutron yield and areal density for OMEGA hydro-equivalent ignition is 3 to 6 × 10 13 and ∼0.3 g/cm 2 , respectively, depending on the level of laser imprinting. This performance has not yet been achieved on OMEGA

Low power arcjet thruster pulse ignition

Science.gov (United States)

Sarmiento, Charles J.; Gruber, Robert P.

1987-01-01

An investigation of the pulse ignition characteristics of a 1 kW class arcjet using an inductive energy storage pulse generator with a pulse width modulated power converter identified several thruster and pulse generator parameters that influence breakdown voltage including pulse generator rate of voltage rise. This work was conducted with an arcjet tested on hydrogen-nitrogen gas mixtures to simulate fully decomposed hydrazine. Over all ranges of thruster and pulser parameters investigated, the mean breakdown voltages varied from 1.4 to 2.7 kV. Ignition tests at elevated thruster temperatures under certain conditions revealed occasional breakdowns to thruster voltages higher than the power converter output voltage. These post breakdown discharges sometimes failed to transition to the lower voltage arc discharge mode and the thruster would not ignite. Under the same conditions, a transition to the arc mode would occur for a subsequent pulse and the thruster would ignite. An automated 11 600 cycle starting and transition to steady state test demonstrated ignition on the first pulse and required application of a second pulse only two times to initiate breakdown.

Capsule Performance Optimization in the National Ignition Campaign

Energy Technology Data Exchange (ETDEWEB)

Landen, O L; MacGowan, B J; Haan, S W; Edwards, J

2009-10-13

A capsule performance optimization campaign will be conducted at the National Ignition Facility to substantially increase the probability of ignition. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the Omega facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

Capsule performance optimization in the national ignition campaign

International Nuclear Information System (INIS)

Landen, O L; MacGowan, B J; Haan, S W; Edwards, J

2010-01-01

A capsule performance optimization campaign will be conducted at the National Ignition Facility [1] to substantially increase the probability of ignition. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the Omega facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

Capsule performance optimization in the national ignition campaign

Science.gov (United States)

Landen, O. L.; MacGowan, B. J.; Haan, S. W.; Edwards, J.

2010-08-01

A capsule performance optimization campaign will be conducted at the National Ignition Facility [1] to substantially increase the probability of ignition. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the Omega facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

Influence of several factors on ignition lag in a compression-ignition engine

Science.gov (United States)

Gerrish, Harold C; Voss, Fred

1932-01-01

This investigation was made to determine the influence of fuel quality, injection advance angle, injection valve-opening pressure, inlet-air pressure, compression ratio, and engine speed on the time lag of auto-ignition of a Diesel fuel oil in a single-cylinder compression-ignition engine as obtained from an analysis of indicator diagrams. Three cam-operated fuel-injection pumps, two pumps cams, and an automatic injection valve with two different nozzles were used. Ignition lag was considered to be the interval between the start of injection of the fuel as determined with a Stroborama and the start of effective combustion as determined from the indicator diagram, the latter being the point where 4.0 x 10(exp-6) pound of fuel had been effectively burned. For this particular engine and fuel it was found that: (1) for a constant start and the same rate of fuel injection up the point of cut-off, a variation in fuel quantity from 1.2 x 10(exp-4) to 4.1 x 10(exp-4) pound per cycle has no appreciable effect on the ignition lag; (2) injection advance angle increases or decreases the lag according to whether density, temperature, or turbulence has the controlling influence; (3) increase in valve-opening pressure slightly increases the lag; and (4) increase of inlet-air pressure, compression ratio, and engine speed reduces the lag.

Misalignment corrections in optical interconnects

Science.gov (United States)

Song, Deqiang

Optical interconnects are considered a promising solution for long distance and high bitrate data transmissions, outperforming electrical interconnects in terms of loss and dispersion. Due to the bandwidth and distance advantage of optical interconnects, longer links have been implemented with optics. Recent studies show that optical interconnects have clear advantages even at very short distances---intra system interconnects. The biggest challenge for such optical interconnects is the alignment tolerance. Many free space optical components require very precise assembly and installation, and therefore the overall cost could be increased. This thesis studied the misalignment tolerance and possible alignment correction solutions for optical interconnects at backplane or board level. First the alignment tolerance for free space couplers was simulated and the result indicated the most critical alignments occur between the VCSEL, waveguide and microlens arrays. An in-situ microlens array fabrication method was designed and experimentally demonstrated, with no observable misalignment with the waveguide array. At the receiver side, conical lens arrays were proposed to replace simple microlens arrays for a larger angular alignment tolerance. Multilayer simulation models in CodeV were built to optimized the refractive index and shape profiles of the conical lens arrays. Conical lenses fabricated with micro injection molding machine and fiber etching were characterized. Active component VCSOA was used to correct misalignment in optical connectors between the board and backplane. The alignment correction capability were characterized for both DC and AC (1GHz) optical signal. The speed and bandwidth of the VCSOA was measured and compared with a same structure VCSEL. Based on the optical inverter being studied in our lab, an all-optical flip-flop was demonstrated using a pair of VCSOAs. This memory cell with random access ability can store one bit optical signal with set or

Development and operation of interconnections in a restructuring context

International Nuclear Information System (INIS)

2003-01-01

In many countries the electrical network is not fully interconnected and the best technical solution to achieve interconnection has to be found. At the same time the electricity industry is being restructured and interconnecting independent energy markets presents technical challenges. It is therefore timely to consider interconnection development and operation options: examine the benefits of interconnecting electrical networks and the development strategies, review the interconnection design options and the technologies available, identify the operational issues, the security problems of large interconnected systems, the protection issues, consider the impact of the restructuring of the electrical supply industry, assess the political, environmental and social implications of interconnections. reorganized in slovenia from 5-7 april 2004. (author)

Enhanced Model for Fast Ignition

Energy Technology Data Exchange (ETDEWEB)

Mason, Rodney J. [Research Applications Corporation, Los Alamos, NM (United States)

2010-10-12

Laser Fusion is a prime candidate for alternate energy production, capable of serving a major portion of the nation's energy needs, once fusion fuel can be readily ignited. Fast Ignition may well speed achievement of this goal, by reducing net demands on laser pulse energy and timing precision. However, Fast Ignition has presented a major challenge to modeling. This project has enhanced the computer code ePLAS for the simulation of the many specialized phenomena, which arise with Fast Ignition. The improved code has helped researchers to understand better the consequences of laser absorption, energy transport, and laser target hydrodynamics. ePLAS uses efficient implicit methods to acquire solutions for the electromagnetic fields that govern the accelerations of electrons and ions in targets. In many cases, the code implements fluid modeling for these components. These combined features, "implicitness and fluid modeling," can greatly facilitate calculations, permitting the rapid scoping and evaluation of experiments. ePLAS can be used on PCs, Macs and Linux machines, providing researchers and students with rapid results. This project has improved the treatment of electromagnetics, hydrodynamics, and atomic physics in the code. It has simplified output graphics, and provided new input that avoids the need for source code access by users. The improved code can now aid university, business and national laboratory users in pursuit of an early path to success with Fast Ignition.

Two-stage Lagrangian modeling of ignition processes in ignition quality tester and constant volume combustion chambers

KAUST Repository

Alfazazi, Adamu; Kuti, Olawole Abiola; Naser, Nimal; Chung, Suk-Ho; Sarathy, Mani

2016-01-01

The ignition characteristics of isooctane and n-heptane in an ignition quality tester (IQT) were simulated using a two-stage Lagrangian (TSL) model, which is a zero-dimensional (0-D) reactor network method. The TSL model was also used to simulate

Development of Augmented Spark Impinging Igniter System for Methane Engines

Science.gov (United States)

Marshall, William M.; Osborne, Robin J.; Greene, Sandra E.

2017-01-01

The Lunar Cargo Transportation and Landing by Soft Touchdown (Lunar CATALYST) program is establishing multiple no-funds-exchanged Space Act Agreement (SAA) partnerships with U.S. private sector entities. The purpose of this program is to encourage the development of robotic lunar landers that can be integrated with U.S. commercial launch capabilities to deliver payloads to the lunar surface. NASA can share technology and expertise under the SAA for the benefit of the CATALYST partners. MSFC seeking to vacuum test Augmented Spark Impinging (ASI) igniter with methane and new exciter units to support CATALYST partners and NASA programs. ASI has previously been used/tested successfully at sea-level, with both O2/CH4 and O2/H2 propellants. Conventional ignition exciter systems historically experienced corona discharge issues in vacuum. Often utilized purging or atmospheric sealing on high voltage lead to remedy. Compact systems developed since PCAD could eliminate the high-voltage lead and directly couple the exciter to the spark igniter. MSFC developed Augmented Spark Impinging (ASI) igniter. Successfully used in several sea-level test programs. Plasma-assisted design. Portion of ox flow is used to generate hot plasma. Impinging flows downstream of plasma. Additional fuel flow down torch tube sleeve for cooling near stoichiometric torch flame. Testing done at NASA GRC Altitude Combustion Stand (ACS) facility 2000-lbf class facility with altitude simulation up to around 100,000 ft. (0.2 psia [10 Torr]) via nitrogen driven ejectors. Propellant conditioning systems can provide temperature control of LOX/CH4 up to test article.

Reconfigurable Optical Interconnections Via Dynamic Computer-Generated Holograms

Science.gov (United States)

Liu, Hua-Kuang (Inventor); Zhou, Shao-Min (Inventor)

1996-01-01

A system is presented for optically providing one-to-many irregular interconnections, and strength-adjustable many-to-many irregular interconnections which may be provided with strengths (weights) w(sub ij) using multiple laser beams which address multiple holograms and means for combining the beams modified by the holograms to form multiple interconnections, such as a cross-bar switching network. The optical means for interconnection is based on entering a series of complex computer-generated holograms on an electrically addressed spatial light modulator for real-time reconfigurations, thus providing flexibility for interconnection networks for large-scale practical use. By employing multiple sources and holograms, the number of interconnection patterns achieved is increased greatly.

An assessment of two off-shore igniter concepts

International Nuclear Information System (INIS)

Guenette, C. C.

1997-01-01

On June 12, 1996, two controlled in-situ oil spill burns (ISB), using a response-prepared ISB system, were conducted in the North Sea, 40 miles off the U. K. coast. The first burn involved fresh crude oil and was ignited with a hand-held igniter using a standard gelled fuel mixture. In the second burn an emulsified crude was used, ignited with a prototype emulsion breaking igniter (EBI) deployed using the Helitorch. The objective was to determine operational practicalities under realistic conditions when responding to a weathered oil situation in an offshore location. This paper is devoted to an assessment of the two igniter systems used during the trials. Results showed that oil aged by 12 hours with a 25 per cent water content burned down to a three-to-four per cent residue. The fire burn survived the two burns intact. The hand-held ignition system worked with fresh oil and the Helitorch lit emulsified oil using EBI. These trials were the first time that the EBI was deployed from a Helitorch slung beneath a helicopter. It was concluded that (1) the simplicity of the logistics required for the hand-held igniter would favour its use over the Helitorch method for fresh or lightly weathered oil, (2) more heavily weathered oils would require the use of an emulsion-breaking type igniter, and (3) aerial deployment of igniters offer the advantage of allowing more accurate positioning. 10 refs.,5 tabs., 3 figs

Gain curves and hydrodynamic modeling for shock ignition

International Nuclear Information System (INIS)

Lafon, M.; Ribeyre, X.; Schurtz, G.

2010-01-01

Ignition of a precompressed thermonuclear fuel by means of a converging shock is now considered as a credible scheme to obtain high gains for inertial fusion energy. This work aims at modeling the successive stages of the fuel time history, from compression to final thermonuclear combustion, in order to provide the gain curves of shock ignition (SI). The leading physical mechanism at work in SI is pressure amplification, at first by spherical convergence, and by collision with the shock reflected at center during the stagnation process. These two effects are analyzed, and ignition conditions are provided as functions of the shock pressure and implosion velocity. Ignition conditions are obtained from a non-isobaric fuel assembly, for which we present a gain model. The corresponding gain curves exhibit a significantly lower ignition threshold and higher target gains than conventional central ignition.

Progress in the indirect-drive National Ignition Campaign

International Nuclear Information System (INIS)

Landen, O L; Benedetti, R; Bleuel, D; Bradley, D K; Caggiano, J A; Callahan, D A; Celliers, P M; Cerjan, C J; Clark, D; Collins, G W; Dewald, E L; Dixit, S N; Doeppner, T; Eggert, J; Farley, D; Glenn, S M; Boehly, T R; Edgell, D; Glebov, V; Frenje, J A

2012-01-01

We have carried out precision optimization of inertial confinement fusion ignition scale implosions. We have achieved hohlraum temperatures in excess of the 300 eV ignition goal with hot-spot symmetry and shock timing near ignition specs. Using slower rise pulses to peak power and extended pulses resulted in lower hot-spot adiabat and higher main fuel areal density at about 80% of the ignition goal. Yields are within a factor of 5–6 of that required to initiate alpha dominated burn. It is likely we will require thicker shells (+15–20%) to reach ignition velocity without mixing of ablator material into the hot spot. (paper)

Seismic qualification of multiple interconnected safety-related cabinets in a high seismic zone

International Nuclear Information System (INIS)

Khan, M.R.; Chen, W.H.W.; Wang, T.Y.

1993-01-01

Certain safety-related multiple, interconnected electrical cabinets and the devices contained therein are required to perform their intended safety functions during and after a design basis seismic event. In general, seismic testing is performed to ensure the structural integrity of the cabinets and the functionality of their associated devices. Constrained by the shake table capacity, seismic testing is usually performed only for a limited number of interconnected cabinets. Also, original shake table tests performed usually did not provide detailed response information at various locations inside the cabinets. For operational and maintenance purposes, doors and panels of some cabinets may need to be opened while the adjacent cabinets are required to remain functional. In addition, in-cabinet response spectra need to be generated for the seismic qualification of new devices and the replacement parts. Consequently, seismic analysis of safety-related multiple, interconnected cabinets is frequently required for configurations which are different from the original tested conditions. This paper presents results of seismic tests of three interconnected safety-related cabinets and finite element analyses performed to compare the analytical results with those obtained from the cabinet seismic tests. Parametric analyses are performed to determine how many panels and doors can be opened while the adjacent cabinets still remain functional. The study indicates that for cabinets located in a high seismic zone, the critical damping of the cabinet is significantly higher than 5% to 7% typically used in qualifying electrical equipment. For devices mounted on the cabinet doors to performed their intended safety function, it requires stiffening of doors and that these doors be properly bolted to the cabinet frame. It also shows that even though doors and panels bolted to the cabinet frame are the primary seismic resistant element of the cabinet, opening of a limited number of them

Laser imprint and implications for direct drive ignition with the National Ignition Facility

International Nuclear Information System (INIS)

Weber, S.V.; Glendinning, S.G.; Kalantar, D.H.; Remington, B.A.; Rothenberg, J.E.

1996-01-01

For direct drive ICF, nonuniformities in laser illumination can seed ripples at the ablation front in a process called imprint. Such nonuniformities will grow during the capsule implosion and can penetrate the capsule shell impede ignition, or degrade burn. We have simulated imprint for a number of experiments on tile Nova laser. Results are in generally good agreement with experimental data. We leave also simulated imprint upon National Ignition Facility (NIF) direct drive ignition capsules. Imprint modulation amplitude comparable to the intrinsic surface finish of ∼40 nm is predicted for a laser bandwidth of 0.5 THz. Ablation front modulations experience growth factors up to several thousand, carrying modulation well into the nonlinear regime. Saturation modeling predicts that the shell should remain intact at the time of peak velocity, but penetration at earlier times appears more marginal

In-vessel remote maintenance of the Compact Ignition Tokamak

International Nuclear Information System (INIS)

Tabor, M.A.; Hager, E.R.; Creedon, R.L.; Fisher, M.V.; Atkin, S.D.

1987-01-01

The Compact Ignition Tokamak (CIT) is the first deuterium-tritium (D-T) fusion device that will study the physics of an ignited plasma. The ability of the tokamak vacuum vessel to be maintained remotely while under vacuum has not been fully demonstrated on previous machines, and this ability will be critical to the efficient and safe operation of ignition devices. Although manned entry into the CIT vacuum vessel will be possible during the nonactivated stages of operation, remotely automated equipment will be used to assist in initial assembly of the vessel as well as to maintain all in-vessel components once the D-T burn is achieved. Remote maintenance and operation will be routinely required for replacement of thermal protection tiles, inspection of components, leak detection, and repair welding activities. Conceptual design to support these remote maintenance activities has been integrated with the conceptual design of the in-vessel components to provide a complete and practical remote maintenance system for CIT. The primary remote assembly and maintenance operations on CIT will be accomplished through two dedicated 37- x 100-cm ports on the main toroidal vessel. Each port contains a single articulated boom manipulator (ABM), which is capable of accessing half of the torus. The proposed ABM consists of a movable carriage assembly, telescoping two-part mast, and articulated link sections. 1 ref

Options for an ignited tokamak

International Nuclear Information System (INIS)

Sheffield, J.

1984-02-01

It is expected that the next phase of the fusion program will involve a tokamak with the goals of providing an ignited plasma for pulses of hundreds of seconds. A simple model is described in this memorandum which establishes the physics conditions for such a self-sustaining plasma, for given ion and electron thermal diffusivities, in terms of R/a, b/a, I, B/q, epsilon β/sub p/, anti T/sub i/, and anti T/sub e//anti T/sub i/. The model is used to produce plots showing the wide range of tokamaks that may ignite or have a given ignition margin. The constraints that limit this range are discussed

Development of a simulation model for compression ignition engine running with ignition improved blend

Directory of Open Access Journals (Sweden)

Sudeshkumar Ponnusamy Moranahalli

2011-01-01

Full Text Available Department of Automobile Engineering, Anna University, Chennai, India. The present work describes the thermodynamic and heat transfer models used in a computer program which simulates the diesel fuel and ignition improver blend to predict the combustion and emission characteristics of a direct injection compression ignition engine fuelled with ignition improver blend using classical two zone approach. One zone consists of pure air called non burning zone and other zone consist of fuel and combustion products called burning zone. First law of thermodynamics and state equations are applied in each of the two zones to yield cylinder temperatures and cylinder pressure histories. Using the two zone combustion model the combustion parameters and the chemical equilibrium composition were determined. To validate the model an experimental investigation has been conducted on a single cylinder direct injection diesel engine fuelled with 12% by volume of 2- ethoxy ethanol blend with diesel fuel. Addition of ignition improver blend to diesel fuel decreases the exhaust smoke and increases the thermal efficiency for the power outputs. It was observed that there is a good agreement between simulated and experimental results and the proposed model requires low computational time for a complete run.

Plasma transport in a compact ignition tokamak

International Nuclear Information System (INIS)

Singer, C.E.; Ku, L.P; Bateman, G.

1987-02-01

Nominal predicted plasma conditions in a compact ignition tokamak are illustrated by transport simulations using experimentally calibrated plasma transport models. The range of uncertainty in these predictions is explored by using various models which have given almost equally good fits to experimental data. Using a transport model which best fits the data, thermonuclear ignition occurs in a Compact Ignition Tokamak design with major radius 1.32 m, plasma half-width 0.43 m, elongation 2.0, and toroidal field and plasma current ramped in six seconds from 1.7 to 10.4 T and 0.7 to 10 MA, respectively. Ignition is facilitated by 20 MW of heating deposited off the magnetic axis near the 3 He minority cyclotron resonance layer. Under these conditions, sawtooth oscillations are small and have little impact on ignition. Tritium inventory is minimized by preconditioning most discharges with deuterium. Tritium is injected, in large frozen pellets, only after minority resonance preheating. Variations of the transport model, impurity influx, heating profile, and pellet ablation rates, have a large effect on ignition and on the maximum beta that can be achieved

Ignition modes of nanosecond discharge with bubbles in distilled water

International Nuclear Information System (INIS)

Hamdan, Ahmad; Cha, Min Suk

2015-01-01

Here, we present the microscopic physical characteristics of nanosecond discharges with an array of bubbles in distilled water. In particular, applying a single high-voltage pulse, four delayed intensified charge-coupled device cameras successfully visualized four successive images during a single discharge event. We identified three distinctive modes of ignition inside a bubble, depending on the relative location of the bubble with respect to pin-to-hollow needle electrodes when a single bubble was located in an inter-electrode gap of 1 mm: anode-driven ignition, cathode-driven ignition, and co-ignition near both electrodes. Anode- and cathode-driven ignitions evolved into either a complete propagation of the streamer or an incomplete propagation, which were limited in location by proximity to an ignition location, while co-ignitions consistently showed complete propagation. When we increased the gap to 2 mm to accommodate multiple bubbles in the gap, an ignited bubble near the cathode was able to cause the ignition of an upper adjacent bubble. Bubble–bubble interface zones can also be spots of ignition, such that we observed simultaneous co-ignitions in the zones of bubble–bubble interfaces and near electrodes with triple bubbles. We compared the experimental results of discharge propagation with different ignition modes between Ar, He, and N 2 bubbles. In addition, numerical simulations for static electric fields reasonably supported observed ignition behavior such that field intensity was locally enhanced. (paper)

Ballistic One-Dimensional InAs Nanowire Cross-Junction Interconnects.

Science.gov (United States)

Gooth, Johannes; Borg, Mattias; Schmid, Heinz; Schaller, Vanessa; Wirths, Stephan; Moselund, Kirsten; Luisier, Mathieu; Karg, Siegfried; Riel, Heike

2017-04-12

Coherent interconnection of quantum bits remains an ongoing challenge in quantum information technology. Envisioned hardware to achieve this goal is based on semiconductor nanowire (NW) circuits, comprising individual NW devices that are linked through ballistic interconnects. However, maintaining the sensitive ballistic conduction and confinement conditions across NW intersections is a nontrivial problem. Here, we go beyond the characterization of a single NW device and demonstrate ballistic one-dimensional (1D) quantum transport in InAs NW cross-junctions, monolithically integrated on Si. Characteristic 1D conductance plateaus are resolved in field-effect measurements across up to four NW-junctions in series. The 1D ballistic transport and sub-band splitting is preserved for both crossing-directions. We show that the 1D modes of a single injection terminal can be distributed into multiple NW branches. We believe that NW cross-junctions are well-suited as cross-directional communication links for the reliable transfer of quantum information as required for quantum computational systems.

47 CFR 90.477 - Interconnected systems.

Science.gov (United States)

2010-10-01

... part and medical emergency systems in the 450-470 MHz band, interconnection will be permitted only... operating on frequencies in the bands below 800 MHz are not subject to the interconnection provisions of...

Kinetic mechanism of plasma-assisted ignition of hydrocarbons

International Nuclear Information System (INIS)

Kosarev, I N; Aleksandrov, N L; Kindysheva, S V; Starikovskaia, S M; Starikovskii, A Yu

2008-01-01

Ignition of hydrocarbon-containing gaseous mixtures has been studied experimentally and numerically under the action of a high-voltage nanosecond discharge at elevated temperatures. Ignition delay times were measured behind a reflected shock wave in stoichiometric C n H 2n+2 : O 2 mixtures (10%) diluted with Ar (90%) for n = 1-5. It was shown that the application of the gas discharge leads to more than an order of magnitude decrease in ignition delay time for all hydrocarbons under consideration. The measured values of ignition delay time agree well with the results of a numerical simulation of the ignition based on the calculation of atom and radical production during the discharge and in its afterglow. The analysis of simulation results showed that a non-equilibrium plasma favours the ignition mainly due to O atoms produced in the active phase of the discharge. (fast track communication)

Preparing for polar-drive ignition on the National Ignition Facility

Directory of Open Access Journals (Sweden)

McKenty P.W.

2013-11-01

Full Text Available The implementation of polar drive (PD at the National Ignition Facility (NIF will enable the execution of direct-drive implosions while the facility is configured for x-ray drive. The Laboratory for Laser Energetics (LLE, in collaboration with LLNL, LANL and GA, is implementing PD on the NIF. LLE has designed and participates in the use of PD implosions for diagnostic commissioning on the NIF. LLE has an active experimental campaign to develop PD in both warm and cryogenic target experiments on OMEGA. LLE and its partners are developing a Polar Drive Project Execution Plan, which will provide a detailed outline of the requirements, resources, and timetable leading to PD-ignition experiments on the NIF.

The National Ignition Facility and the Promise of Inertial Fusion Energy

International Nuclear Information System (INIS)

Moses, E.I.

2010-01-01

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational. The NIF is the world's most energetic laser system capable of producing 1.8 MJ and 500 TW of ultraviolet light. By concentrating the energy from its 192 extremely energetic laser beams into a mm 3 -sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm 3 , and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in planetary interiors and stellar environments. On September 29, 2010, the first integrated ignition experiment was conducted, demonstrating the successful coordination of the laser, cryogenic target system, array of diagnostics and infrastructure required for ignition demonstration. In light of this strong progress, the U.S. and international communities are examining the implication of NIF ignition for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10-20 Hz and a laser with 10% electrical-optical efficiency, as well as further development and advances in large-scale target fabrication, target injection, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in the 10- to 15-year time frame. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Engine (LIFE) concept and examining in detail various technology choices, as well as the advantages of both pure fusion and fusion-fission schemes. This paper will describe the unprecedented experimental capabilities of the NIF and the results achieved so far on the path toward ignition. The paper will conclude with a discussion about the need to build on the progress on NIF to develop an implementable and effective plan to achieve the promise of LIFE as a source of carbon-free energy.

The National Ignition Facility and the Promise of Inertial Fusion Energy

Energy Technology Data Exchange (ETDEWEB)

Moses, E I

2010-12-13

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational. The NIF is the world's most energetic laser system capable of producing 1.8 MJ and 500 TW of ultraviolet light. By concentrating the energy from its 192 extremely energetic laser beams into a mm{sup 3}-sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm{sup 3}, and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in planetary interiors and stellar environments. On September 29, 2010, the first integrated ignition experiment was conducted, demonstrating the successful coordination of the laser, cryogenic target system, array of diagnostics and infrastructure required for ignition demonstration. In light of this strong progress, the U.S. and international communities are examining the implication of NIF ignition for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10-20 Hz and a laser with 10% electrical-optical efficiency, as well as further development and advances in large-scale target fabrication, target injection, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in the 10- to 15-year time frame. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Engine (LIFE) concept and examining in detail various technology choices, as well as the advantages of both pure fusion and fusion-fission schemes. This paper will describe the unprecedented experimental capabilities of the NIF and the results achieved so far on the path toward ignition. The paper will conclude with a discussion about the need to build on the progress on NIF to develop an implementable and effective plan to achieve the promise of LIFE as a source of carbon-free energy.

Fast-shock ignition: a new approach to inertial confinement fusion

Directory of Open Access Journals (Sweden)

AH Farahbod

2013-03-01

Full Text Available  A new concept for inertial confinement fusion called fast-shock ignition (FSI is introduced as a credible scheme in order to obtain high target gain. In the proposed model, the separation of fuel ignition into two successive steps, under the suitable conditions, reduces required ignitor energy for the fuel ignition. The main procedure in FSI concept is compressing the fuel up to stagnation. Then, two high intensity short pulse laser spikes with energy and power lower than those required for shock ignition (SI and fast ignition (FI with a proper delay time are launched at the fuel which increases the central hot-spot temperature and completes the ignition of the precompressed fuel. The introduced semi-analytical model indicates that with fast-shock ignition, the total required energy for compressing and igniting the fuel can be slightly reduced in comparison to pure shock ignition. Furthermore, for fuel mass greater than , the target energy gain increases up to 15 percent and the contribution of fast ignitor under the proper conditions could be decreased about 20 percent compared with pure fast ignition. The FSI scheme is beneficial from technological considerations for the construction of short pulse high power laser drivers. The general advantages of fast-shock ignition over pure shock ignition in terms of figure of merit can be more than 1.3.

Investigating antennas as ignition aid for automotive HID lamps

International Nuclear Information System (INIS)

Bergner, A; Engelhardt, M; Bienholz, S; Ruhrmann, C; Hoebing, T; Groeger, S; Mentel, J; Awakowicz, P

2015-01-01

This paper considers the ignition of mercury-free high-intensity discharge (HID) lamps for car headlights. Due to safety reasons, these lamps need to have a fast run-up phase which is ensured, amongst other things, by a high Xe pressure of roughly 15 bar (cold) in the discharge vessel. The high Xe pressure causes an increased ignition voltage compared with former mercury-containing automotive HID lamps or low-pressure lamps used for general-lighting applications. The increase in ignition voltage can be limited if the electric field in front of the electrodes is raised by an uplifting of the electrical conductivity along the outer wall of the inner bulb either by a conductive layer on its surface or by a dielectric barrier discharge (DBD) within the outer bulb. This paper considers on the one hand conventional antennas deposited by physical vapour deposition (PVD) and on the other hand a combination of these antennas with a DBD within the outer-bulb operated in 100 mbar Ar as ignition aids. In both cases the antenna potential and antenna width are varied. Additionally, the effects of antenna thickness and antenna material are investigated. The ignition voltage, ignition current and light emission during ignition are measured on a nanosecond timescale. Furthermore, for the very first time, the ignition process is recorded in four consecutive intensified charge-coupled device images using a high-speed camera system with a time resolution in the range of nanoseconds. It was found that antennas strongly reduce the ignition voltage of automotive HID lamps. Active antennas reduce the ignition voltage significantly more than passive antennas, proportional to the conductance of the antenna. Combining conventional antennas with an outer-bulb discharge reduces the ignition voltage from 19 kV without any ignition aid to the intrinsic ignition voltage of the lamp below 10 kV, in the best case. (paper)

Ignition experiment in a single-turn-coil tokamak

International Nuclear Information System (INIS)

Carrera, R.; Driga, M.; Gully, J.H.

1989-01-01

A novel concept for a fusion ignition experiment, IGNITEX proposed along the lines of previous ideas for a compact thermonuclear device is analyzed. A single-turn-coil tokamak is analyzed. A single-turn-coil tokamak supplied by homopolar generators can ohmically heat a DT plasma to ignition conditions and maintain a thermally stable ignited phase for about ten energy confinement times. The IGNITEX experiment can provide a simple and relatively inexpensive way to produce and control ignited plasmas for scientific study

Ignition et oxydation des particules de combustible solide pulvérisé Ignition and Oxidation of Pulverized Solid Fuel

Directory of Open Access Journals (Sweden)

De Soete G. G.

2006-11-01

Full Text Available On présente dans cet article, en utilisant la méthode du ruban chauffé, une étude de la compétition entre (1 la dévolatilisation et l'oxydation consécutive des produits de pyrolyse et (2 l'ignition de la matrice solide et sa combustion rapide. La comparaison entre le moment de l'ignition et le début de la pyrolyse permet de déterminer en fonction de la température, de la taille des particules et de la concentration en oxygène, le domaine dans lequel l'ignition d'un combustible solide pyrolysable est du type whole coal ignition (c'est-à-dire lorsque l'ignition intervient avant que la pyrolyse devienne mesurable. Les résultats suggèrent que ce type d'ignition doit s'effectuer en règle générale dans les conditions de mise en oeuvre des combustibles solides pulvérisés dans les flammes industrielles. Dans le cas de l'ignition whole coal , la vitesse de combustion de la matrice solide est inhibée dans la période qui suit l'ignition. Cette inhibition est due d'une part à la difficulté pour l'oxygène de diffuser dans les pores pendant la sortie des produits de pyrolyse, et d'autre part à la consommation préférentielle de l'oxygène dans l'oxydation des produits de pyrolyse, principalement dans le cas où cette oxydation se développe sous forme de flamme. Ce n'est que lorsque la pyrolyse s'achève que la vitesse de combustion hétérogène peut atteindre sa valeur stationnaire normale, qui est alors pratiquement identique à celle du coke. Aux températures situées entre la température d'ignition du combustible solide et la température d'extinction du coke résiduel, la combustion est incomplète, une extinction intervenant à un degré de dévolatilisation d'autant plus grande que la température est élevée. Ce phénomène s'explique qualitativement par la théorie classique d'ignition thermique lorsqu'on l'applique au cas particulier des combustibles solides pyrolysables. Les températures d'ignition ainsi que les d

Target designs for energetics experiments on the National Ignition Facility

International Nuclear Information System (INIS)

Meezan, N B; Glenzer, S H; Suter, L J

2008-01-01

The goal of the first hohlraum energetics experiments on the National Ignition Facility (NIF) [G. H. Miller et al, Optical Eng. 43, 2841 (2004)] is to select the hohlraum design for the first ignition experiments. Sub-scale hohlraums heated by 96 of the 192 laser beams on the NIF are used to emulate the laser-plasma interaction behavior of ignition hohlraums. These 'plasma emulator' targets are 70% scale versions of the 1.05 MJ, 300 eV ignition hohlraum and have the same energy-density as the full-scale ignition designs. Radiation-hydrodynamics simulations show that the sub-scale target is a good emulator of plasma conditions inside the ignition hohlraum, reproducing density n e within 10% and temperature T e within 15% along a laser beam path. Linear backscatter gain analysis shows the backscatter risk to be comparable to that of the ignition target. A successful energetics campaign will allow the National Ignition Campaign to focus its efforts on optimizing ignition hohlraums with efficient laser coupling

On the assessment of performance and emissions characteristics of a SI engine provided with a laser ignition system

Science.gov (United States)

Birtas, A.; Boicea, N.; Draghici, F.; Chiriac, R.; Croitoru, G.; Dinca, M.; Dascalu, T.; Pavel, N.

2017-10-01

Performance and exhaust emissions of spark ignition engines are strongly dependent on the development of the combustion process. Controlling this process in order to improve the performance and to reduce emissions by ensuring rapid and robust combustion depends on how ignition stage is achieved. An ignition system that seems to be able for providing such an enhanced combustion process is that based on plasma generation using a Q-switched solid state laser that delivers pulses with high peak power (of MW-order level). The laser-spark devices used in the present investigations were realized using compact diffusion-bonded Nd:YAG/Cr4+:YAG ceramic media. The laser igniter was designed, integrated and built to resemble a classical spark plug and therefore it could be mounted directly on the cylinder head of a passenger car engine. In this study are reported the results obtained using such ignition system provided for a K7M 710 engine currently produced by Renault-Dacia, where the standard calibrations were changed towards the lean mixtures combustion zone. Results regarding the performance, the exhaust emissions and the combustion characteristics in optimized spark timing conditions, which demonstrate the potential of such an innovative ignition system, are presented.

Capsule performance optimization in the National Ignition Campaigna)

Science.gov (United States)

Landen, O. L.; Boehly, T. R.; Bradley, D. K.; Braun, D. G.; Callahan, D. A.; Celliers, P. M.; Collins, G. W.; Dewald, E. L.; Divol, L.; Glenzer, S. H.; Hamza, A.; Hicks, D. G.; Hoffman, N.; Izumi, N.; Jones, O. S.; Kirkwood, R. K.; Kyrala, G. A.; Michel, P.; Milovich, J.; Munro, D. H.; Nikroo, A.; Olson, R. E.; Robey, H. F.; Spears, B. K.; Thomas, C. A.; Weber, S. V.; Wilson, D. C.; Marinak, M. M.; Suter, L. J.; Hammel, B. A.; Meyerhofer, D. D.; Atherton, J.; Edwards, J.; Haan, S. W.; Lindl, J. D.; MacGowan, B. J.; Moses, E. I.

2010-05-01

A capsule performance optimization campaign will be conducted at the National Ignition Facility [G. H. Miller et al., Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition by laser-driven hohlraums [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)]. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the OMEGA facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

Capsule performance optimization in the National Ignition Campaign

International Nuclear Information System (INIS)

Landen, O. L.; Bradley, D. K.; Braun, D. G.; Callahan, D. A.; Celliers, P. M.; Collins, G. W.; Dewald, E. L.; Divol, L.; Glenzer, S. H.; Hamza, A.; Hicks, D. G.; Izumi, N.; Jones, O. S.; Kirkwood, R. K.; Michel, P.; Milovich, J.; Munro, D. H.; Robey, H. F.; Spears, B. K.; Thomas, C. A.

2010-01-01

A capsule performance optimization campaign will be conducted at the National Ignition Facility [G. H. Miller et al., Nucl. Fusion 44, 228 (2004)] to substantially increase the probability of ignition by laser-driven hohlraums [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)]. The campaign will experimentally correct for residual uncertainties in the implosion and hohlraum physics used in our radiation-hydrodynamic computational models before proceeding to cryogenic-layered implosions and ignition attempts. The required tuning techniques using a variety of ignition capsule surrogates have been demonstrated at the OMEGA facility under scaled hohlraum and capsule conditions relevant to the ignition design and shown to meet the required sensitivity and accuracy. In addition, a roll-up of all expected random and systematic uncertainties in setting the key ignition laser and target parameters due to residual measurement, calibration, cross-coupling, surrogacy, and scale-up errors has been derived that meets the required budget.

Chip-package nano-structured copper and nickel interconnections with metallic and polymeric bonding interfaces

Science.gov (United States)

Aggarwal, Ankur

With the semiconductor industry racing toward a historic transition, nano chips with less than 45 nm features demand I/Os in excess of 20,000 that support computing speed in terabits per second, with multi-core processors aggregately providing highest bandwidth at lowest power. On the other hand, emerging mixed signal systems are driving the need for 3D packaging with embedded active components and ultra-short interconnections. Decreasing I/O pitch together with low cost, high electrical performance and high reliability are the key technological challenges identified by the 2005 International Technology Roadmap for Semiconductors (ITRS). Being able to provide several fold increase in the chip-to-package vertical interconnect density is essential for garnering the true benefits of nanotechnology that will utilize nano-scale devices. Electrical interconnections are multi-functional materials that must also be able to withstand complex, sustained and cyclic thermo-mechanical loads. In addition, the materials must be environmentally-friendly, corrosion resistant, thermally stable over a long time, and resistant to electro-migration. A major challenge is also to develop economic processes that can be integrated into back end of the wafer foundry, i.e. with wafer level packaging. Device-to-system board interconnections are typically accomplished today with either wire bonding or solders. Both of these are incremental and run into either electrical or mechanical barriers as they are extended to higher density of interconnections. Downscaling traditional solder bump interconnect will not satisfy the thermo-mechanical reliability requirements at very fine pitches of the order of 30 microns and less. Alternate interconnection approaches such as compliant interconnects typically require lengthy connections and are therefore limited in terms of electrical properties, although expected to meet the mechanical requirements. A novel chip-package interconnection technology is

Effects of electrode geometry on transient plasma induced ignition

International Nuclear Information System (INIS)

Shukla, B; Gururajan, V; Eisazadeh-Far, K; Windom, B; Egolfopoulos, F N; Singleton, D; Gundersen, M A

2013-01-01

Achieving effective ignition of reacting mixtures using nanosecond pulsed discharge non-equilibrium transient plasma (TP), requires that the effects of several experimental parameters be quantified and understood. Among them are the electrode geometry, the discharge location especially in non-premixed systems, and the relative ignition performance by spark and TP under the same experimental conditions. In the present investigation, such issues were addressed experimentally using a cylindrical constant volume combustion chamber and a counterflow flame configuration coupled with optical shadowgraph that enables observation of how and where the ignition process starts. Results were obtained under atmospheric pressure and showed that the electrode geometry has a notable influence on ignition, with the needle-to-semicircle exhibiting the best ignition performance. Furthermore, it was determined that under non-premixed conditions discharging TP in the reactants mixing layer was most effective in achieving ignition. It was also determined that in the cases considered, the TP induced ignition initiates from the needle head where the electric field and electron densities are the highest. In the case of a spark, however, ignition was found to initiate always from the hot region between the two electrodes. Comparison of spark and TP discharges in only air (i.e. without fuel) and ignition phenomena induced by them also suggest that in the case of TP ignition is at least partly non-thermal and instead driven by the production of active species. Finally, it was determined that single pulsed TP discharges are sufficient to ignite both premixed and non-premixed flames of a variety of fuels ranging from hydrogen to heavy fuels including F-76 diesel and IFO380 bunker fuel even at room temperature. (paper)

Production and characterization of SLID interconnected n-in-p pixel modules with 75 micron thin silicon sensors

CERN Document Server

Andricek, L; Macchiolo, A; Moser, H.G; Nisius, R; Richter, R.H; Terzo, S; Weigell, P

2014-01-01

The performance of pixel modules built from 75 micrometer thin silicon sensors and ATLAS read-out chips employing the Solid Liquid InterDiffusion (SLID) interconnection technology is presented. This technology, developed by the Fraunhofer EMFT, is a possible alternative to the standard bump-bonding. It allows for stacking of different interconnected chip and sensor layers without destroying the already formed bonds. In combination with Inter-Chip-Vias (ICVs) this paves the way for vertical integration. Both technologies are combined in a pixel module concept which is the basis for the modules discussed in this paper. Mechanical and electrical parameters of pixel modules employing both SLID interconnections and sensors of 75 micrometer thickness are covered. The mechanical features discussed include the interconnection efficiency, alignment precision and mechanical strength. The electrical properties comprise the leakage currents, tuning characteristics, charge collection, cluster sizes and hit efficiencies. T...

Production and Characterisation of SLID Interconnected n-in-p Pixel Modules with 75 Micrometer Thin Silicon Sensors

CERN Document Server

Andricek, L; Macchiolo, A.; Moser, H.-G.; Nisius, R.; Richter, R.H.; Terzo, S.; Weigell, P.

2014-01-01

The performance of pixel modules built from 75 micrometer thin silicon sensors and ATLAS read-out chips employing the Solid Liquid InterDiffusion (SLID) interconnection technology is presented. This technology, developed by the Fraunhofer EMFT, is a possible alternative to the standard bump-bonding. It allows for stacking of different interconnected chip and sensor layers without destroying the already formed bonds. In combination with Inter-Chip-Vias (ICVs) this paves the way for vertical integration. Both technologies are combined in a pixel module concept which is the basis for the modules discussed in this paper. Mechanical and electrical parameters of pixel modules employing both SLID interconnections and sensors of 75 micrometer thickness are covered. The mechanical features discussed include the interconnection efficiency, alignment precision and mechanical strength. The electrical properties comprise the leakage currents, tunability, charge collection, cluster sizes and hit efficiencies. Targeting at ...

Electron transport and shock ignition

Energy Technology Data Exchange (ETDEWEB)

Bell, A R; Tzoufras, M, E-mail: t.bell1@physics.ox.ac.uk [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom)

2011-04-15

Inertial fusion energy (IFE) offers one possible route to commercial energy generation. In the proposed 'shock ignition' route to fusion, the target is compressed at a relatively low temperature and then ignited using high intensity laser irradiation which drives a strong converging shock into the centre of the fuel. With a series of idealized calculations we analyse the electron transport of energy into the target, which produces the pressure responsible for driving the shock. We show that transport in shock ignition lies near the boundary between ablative and heat front regimes. Moreover, simulations indicate that non-local effects are significant in the heat front regime and might lead to increased efficiency by driving the shock more effectively and reducing heat losses to the plasma corona.

2D and 3D interconnect fabrication by picosecond Laser Induced Forward Transfer

NARCIS (Netherlands)

Oosterhuis, G.; Huis in 't veld, A.J.; Chall, P.

2011-01-01

Interconnects are an important cost driver in advanced 3D chip packaging. This holds for Through Silicon Vias (TSV) for chip stacking, but also for other integrated Si-technology. Especially in applications with a low number (<100 mm-2) of relatively large (10-2- um diameter), high aspect ratio

A mechanistic approach to safe igniter implementation for hydrogen mitigation

International Nuclear Information System (INIS)

Breitung, W.; Dorofeev, S.B.; Travis, J.R.

1997-01-01

A new methodology for safe igniter implementation in a full-scale 3-d containment is described. The method consists of the following steps: determination of bounding H 2 /steam sources; high-resolution analysis of the 3-d transport and mixing processes; evaluation of the detonation potential at the time of ignition; optimization of the igniter system such that only early ignition and nonenergetic combustion occurs; and modelling of the continuous deflagration processes during H 2 -release. The method was implemented into the GASFLOW code. The principle and the feasibility is demonstrated for a single room geometry. A full-scale 3-d reactor case is analyzed without and with deliberate ignition, assuming a severe dry H 2 release sequence (1200 kg). In the unmitigated case significant DDT potential in the whole containment develops, including the possibility of global detonations. The analysis with igniters in different positions predicted deflagration or detonation in the break compartment, depending on the igniter location. Igniter positions were found which lead to early ignition, effective H 2 -removal, and negligible pressure loads. The approach can be used to determine number, position and frequency of a safe igniter system for a given large dry containment. (author)

Electrical tomography using atomic force microscopy and its application towards carbon nanotube-based interconnects

International Nuclear Information System (INIS)

Schulze, A; Hantschel, T; Dathe, A; Eyben, P; Vandervorst, W; Ke, X

2012-01-01

The fabrication and integration of low-resistance carbon nanotubes (CNTs) for interconnects in future integrated circuits requires characterization techniques providing structural and electrical information at the nanometer scale. In this paper we present a slice-and-view approach based on electrical atomic force microscopy. Material removal achieved by successive scanning using doped ultra-sharp full-diamond probes, manufactured in-house, enables us to acquire two-dimensional (2D) resistance maps originating from different depths (equivalently different CNT lengths) on CNT-based interconnects. Stacking and interpolating these 2D resistance maps results in a three-dimensional (3D) representation (tomogram). This allows insight from a structural (e.g. size, density, distribution, straightness) and electrical point of view simultaneously. By extracting the resistance evolution over the length of an individual CNT we derive quantitative information about the resistivity and the contact resistance between the CNT and bottom electrode. (paper)

Advances for laser ignition of internal combustion and rocket engines

International Nuclear Information System (INIS)

Schwarz, E.

2011-01-01

The scope of the PhD thesis presented here is the investigation of theoretical and practical aspects of laser-induced spark ignition and laser thermal ignition. Laser ignition systems are currently undergoing a rapidly development with growing intensity involving more and more research groups who mainly concentrate on the field of car and large combustion engines. This research is primarily driven by the engagement to meet the increasingly strict emission limits and by the intention to use the limited energy reserves more efficiently. For internal combustion engines, laser plasma-induced ignition will allow to combine the goals for legally required reductions of pollutant emissions and higher engine efficiencies. Also for rocket engines laser ignition turns out to be very attractive. A highly reliable ignition system like laser ignition would represent an option for introducing non-toxic propellants in order to replace highly toxic and carcinogenic hydrazine-based propellants commonly used in launch vehicle upper stages and satellites. The most important results on laser ignition and laser plasma generation, accomplished by the author and, in some respects, enriched by cooperation with colleagues are presented in the following. The emphasis of this thesis is placed on the following issues: - Two-color effects on laser plasma generation - Theoretical considerations about the focal volume concerning plasma generation - Plasma transmission experiments - Ignition experiments on laser-induced ignition - Ignition experiments on thermally-induced ignition - Feasibility study on laser ignition of rocket engines The purpose of the two-color laser plasma experiments is to investigate possible constructive interference effects of driving fields that are not monochromatic, but contain (second) harmonic radiation with respect to the goal of lowering the plasma generation threshold. Such effects have been found in a number of related processes, such as laser ablation or high

Evaluation of the ignition behaviour of coals and blends

Energy Technology Data Exchange (ETDEWEB)

J. Faundez; F. Rubiera; X. Garcia; A. Arenillas; A.L. Gordon; J.J. Pis [CSIC, Instituto Nacional del Carbon, Oviedo (Spain). Department of Energy and Environment

2003-07-01

An experimental study about ignition of coals and blends was carried out by using an entrained flow reactor (EFR) with continuous feed. Seven coals of varying rank, from subbituminous to semianthracite, were tested and evolving gases (O{sub 2}, CO, CO{sub 2}, NO) were measured. The ignition temperature was evaluated from the evolution profiles of these gases, and correlated inversely to the reactivity of coals, as reflected by increasing values of ignition temperatures in the sequence subbituminous, high volatile bituminous, low volatile bituminous and semianthracite coals. Mechanism of ignition varied from an heterogeneous mechanism (for subbituminous, low volatile bituminous and semianthracite coals) to an homogeneous mechanism (for high volatile bituminous coal). Experiments with coal blends showed that if a low volatile bituminous coal is blended with a high volatile bituminous coal, the latter determines the value of the ignition temperature and ignition mechanism of the blend, when its percentage in the blend is 50% or higher. For blends of subbituminous and high volatile bituminous coals, the ignition mechanism of the blend is determined by the ignition mechanism of the coal with a higher content in the blend. 12 refs., 9 figs., 1 tab.

Manufacturing of planar ceramic interconnects

Energy Technology Data Exchange (ETDEWEB)

Armstrong, B.L.; Coffey, G.W.; Meinhardt, K.D.; Armstrong, T.R. [Pacific Northwest National Lab., Richland, WA (United States)

1996-12-31

The fabrication of ceramic interconnects for solid oxide fuel cells (SOFC) and separator plates for electrochemical separation devices has been a perennial challenge facing developers. Electrochemical vapor deposition (EVD), plasma spraying, pressing, tape casting and tape calendering are processes that are typically utilized to fabricate separator plates or interconnects for the various SOFC designs and electrochemical separation devices. For sake of brevity and the selection of a planar fuel cell or gas separation device design, pressing will be the only fabrication technique discussed here. This paper reports on the effect of the characteristics of two doped lanthanum manganite powders used in the initial studies as a planar porous separator for a fuel cell cathode and as a dense interconnect for an oxygen generator.

Approach to ignition of tokamak reactors

International Nuclear Information System (INIS)

Sigmar, D.J.

1981-02-01

Recent transport modeling results for JET, INTOR, and ETF are reviewed and analyzed with respect to existing uncertainties in the underlying physics, the self-consistency of the very large numerical codes, and the margin for ignition. The codes show ignition to occur in ETF/INTOR-sized machines if empirical scaling can be extrapolated to ion temperatures (and beta values) much higher than those presently achieved, if there is no significant impurity accumulation over the first 7 s, and if the known ideal and resistive MHD instabilities remain controllable for the evolving plasma profiles during ignition startup

Overview of the Compact Ignition Tokamak

International Nuclear Information System (INIS)

Flanagan, C.A.

1986-01-01

The mission of CIT is to realize, study, and optimize fully ignited plasma discharges. The physics requirements have been established to provide reasonable assurance that the mission will be achieved: (1) plasma confinement guidelines consider all present scaling laws; ohmic, auxiliary heated L-mode, auxiliary heated H-mode, (2) figure-of-merit established: X = aB/q; this is proportional to ignition margin; X must be >25, (3) burn pulse duration set at ten times tau-E; an additional two times tau-E specified to heat to ignition, and (4) capability to operate both in limiter and divertor mode

Hydrodynamic modeling and simulations of shock ignition thresholds

Directory of Open Access Journals (Sweden)

Lafon M.

2013-11-01

Full Text Available The Shock Ignition (SI scheme [1] offers to reduce the laser requirements by relaxing the implosion phase to sub-ignition velocities and later adding an intense laser spike. Depending on laser energy, target characteristics and implosion velocity, high gains are expected [2,3]. Relevant intensities for scaled targets imploded in the velocity range from 150 to 400 km/s are defined at ignition thresholds. A range of moderate implosion velocities is specified to match safe implosions. These conditions for target design are then inferred for relevant NIF and LMJ shock-ignited targets.

A Survey of Studies on Ignition and Burn of Inertially Confined Fuels

Science.gov (United States)

Atzeni, Stefano

2016-10-01

A survey of studies on ignition and burn of inertial fusion fuels is presented. Potentials and issues of different approaches to ignition (central ignition, fast ignition, volume ignition) are addressed by means of simple models and numerical simulations. Both equimolar DT and T-lean mixtures are considered. Crucial issues concerning hot spot formation (implosion symmetry for central ignition; igniting pulse parameters for fast ignition) are briefly discussed. Recent results concerning the scaling of the ignition energy with the implosion velocity and constrained gain curves are also summarized.

Analytical model for fast-shock ignition

International Nuclear Information System (INIS)

Ghasemi, S. A.; Farahbod, A. H.; Sobhanian, S.

2014-01-01

A model and its improvements are introduced for a recently proposed approach to inertial confinement fusion, called fast-shock ignition (FSI). The analysis is based upon the gain models of fast ignition, shock ignition and considerations for the fast electrons penetration into the pre-compressed fuel to examine the formation of an effective central hot spot. Calculations of fast electrons penetration into the dense fuel show that if the initial electron kinetic energy is of the order ∼4.5 MeV, the electrons effectively reach the central part of the fuel. To evaluate more realistically the performance of FSI approach, we have used a quasi-two temperature electron energy distribution function of Strozzi (2012) and fast ignitor energy formula of Bellei (2013) that are consistent with 3D PIC simulations for different values of fast ignitor laser wavelength and coupling efficiency. The general advantages of fast-shock ignition in comparison with the shock ignition can be estimated to be better than 1.3 and it is seen that the best results can be obtained for the fuel mass around 1.5 mg, fast ignitor laser wavelength ∼0.3  micron and the shock ignitor energy weight factor about 0.25

A low-cost, manufacturable method for fabricating capillary and optical fiber interconnects for microfluidic devices.

Science.gov (United States)

Hartmann, Daniel M; Nevill, J Tanner; Pettigrew, Kenneth I; Votaw, Gregory; Kung, Pang-Jen; Crenshaw, Hugh C

2008-04-01

Microfluidic chips require connections to larger macroscopic components, such as light sources, light detectors, and reagent reservoirs. In this article, we present novel methods for integrating capillaries, optical fibers, and wires with the channels of microfluidic chips. The method consists of forming planar interconnect channels in microfluidic chips and inserting capillaries, optical fibers, or wires into these channels. UV light is manually directed onto the ends of the interconnects using a microscope. UV-curable glue is then allowed to wick to the end of the capillaries, fibers, or wires, where it is cured to form rigid, liquid-tight connections. In a variant of this technique, used with light-guiding capillaries and optical fibers, the UV light is directed into the capillaries or fibers, and the UV-glue is cured by the cone of light emerging from the end of each capillary or fiber. This technique is fully self-aligned, greatly improves both the quality and the manufacturability of the interconnects, and has the potential to enable the fabrication of interconnects in a fully automated fashion. Using these methods, including a semi-automated implementation of the second technique, over 10,000 interconnects have been formed in almost 2000 microfluidic chips made of a variety of rigid materials. The resulting interconnects withstand pressures up to at least 800psi, have unswept volumes estimated to be less than 10 femtoliters, and have dead volumes defined only by the length of the capillary.

Laser ignition of a multi-injector LOX/methane combustor

Science.gov (United States)

Börner, Michael; Manfletti, Chiara; Hardi, Justin; Suslov, Dmitry; Kroupa, Gerhard; Oschwald, Michael

2018-06-01

This paper reports the results of a test campaign of a laser-ignited combustion chamber with 15 shear coaxial injectors for the propellant combination LOX/methane. 259 ignition tests were performed for sea-level conditions. The igniter based on a monolithic ceramic laser system was directly attached to the combustion chamber and delivered 20 pulses with individual pulse energies of {33.2 ± 0.8 mJ } at 1064 nm wavelength and 2.3 ns FWHM pulse length. The applicability, reliability, and reusability of this ignition technology are demonstrated and the associated challenges during the start-up process induced by the oxygen two-phase flow are formulated. The ignition quality and pressure dynamics are evaluated using 14 dynamic pressure sensors distributed both azimuthally and axially along the combustion chamber wall. The influence of test sequencing on the ignition process is briefly discussed and the relevance of the injection timing of the propellants for the ignition process is described. The flame anchoring and stabilization process, as monitored using an optical probe system close to the injector faceplate connected to photomultiplier elements, is presented. For some of the ignition tests, non-uniform anchoring was detected with no influence onto the anchoring at steady-state conditions. The non-uniform anchoring can be explained by the inhomogeneous, transient injection of the two-phase flow of oxygen across the faceplate. This characteristic is verified by liquid nitrogen cold flow tests that were recorded by high-speed imaging. We conclude that by adapting the ignition sequence, laser ignition by optical breakdown of the propellants within the shear layer of a coaxial shear injector is a reliable ignition technology for LOX/methane combustors without significant over-pressure levels.

Laser ignition of a multi-injector LOX/methane combustor

Science.gov (United States)

Börner, Michael; Manfletti, Chiara; Hardi, Justin; Suslov, Dmitry; Kroupa, Gerhard; Oschwald, Michael

2018-02-01

This paper reports the results of a test campaign of a laser-ignited combustion chamber with 15 shear coaxial injectors for the propellant combination LOX/methane. 259 ignition tests were performed for sea-level conditions. The igniter based on a monolithic ceramic laser system was directly attached to the combustion chamber and delivered 20 pulses with individual pulse energies of {33.2 ± 0.8 mJ } at 1064 nm wavelength and 2.3 ns FWHM pulse length. The applicability, reliability, and reusability of this ignition technology are demonstrated and the associated challenges during the start-up process induced by the oxygen two-phase flow are formulated. The ignition quality and pressure dynamics are evaluated using 14 dynamic pressure sensors distributed both azimuthally and axially along the combustion chamber wall. The influence of test sequencing on the ignition process is briefly discussed and the relevance of the injection timing of the propellants for the ignition process is described. The flame anchoring and stabilization process, as monitored using an optical probe system close to the injector faceplate connected to photomultiplier elements, is presented. For some of the ignition tests, non-uniform anchoring was detected with no influence onto the anchoring at steady-state conditions. The non-uniform anchoring can be explained by the inhomogeneous, transient injection of the two-phase flow of oxygen across the faceplate. This characteristic is verified by liquid nitrogen cold flow tests that were recorded by high-speed imaging. We conclude that by adapting the ignition sequence, laser ignition by optical breakdown of the propellants within the shear layer of a coaxial shear injector is a reliable ignition technology for LOX/methane combustors without significant over-pressure levels.

100 GHz Externally Modulated Laser for Optical Interconnects Applications

DEFF Research Database (Denmark)

Ozolins, Oskars; Pang, Xiaodan; Iglesias Olmedo, Miguel

2017-01-01

We report on a 116 Gb/s on-off keying (OOK), four pulse amplitude modulation (PAM) and 105-Gb/s 8-PAM optical transmitter using an InP-based integrated and packaged externally modulated laser for high-speed optical interconnects with up to 30 dB static extinction ratio and over 100-GHz 3-d......B bandwidth with 2 dB ripple. In addition, we study the tradeoff between power penalty and equalizer length to foresee transmission distances with standard single mode fiber....

Experimental and Numerical Study of Jet Controlled Compression Ignition on Combustion Phasing Control in Diesel Premixed Compression Ignition Systems

Directory of Open Access Journals (Sweden)

Qiang Zhang

2014-07-01

Full Text Available In order to directly control the premixed combustion phasing, a Jet Controlled Compression Ignition (JCCI for diesel premixed compression ignition systems is investigated. Experiments were conducted on a single cylinder natural aspirated diesel engine without EGR at 3000 rpm. Numerical models were validated by load sweep experiments at fixed spark timing. Detailed combustion characteristics were analyzed based on the BMEP of 2.18 bar. The simulation results showed that the high temperature jets of reacting active radical species issued from the ignition chamber played an important role on the onset of combustion in the JCCI system. The combustion of diesel pre-mixtures was initiated rapidly by the combustion products issued from the ignition chamber. Moreover, the flame propagation was not obvious, similar to that in Pre-mixed Charge Compression Ignition (PCCI. Consequently, spark timing sweep experiments were conducted. The results showed a good linear relationship between spark timing in the ignition chamber and CA10 and CA50, which indicated the ability for direct combustion phasing control in diesel PCCI. The NOx and soot emissions gradually changed with the decrease of spark advance angle. The maximum reduction of NOx and soot were both over 90%, and HC and CO emissions were increased.

Experimental results pertaining to the performance of thermal igniters

International Nuclear Information System (INIS)

Carmel, M.K.

1989-10-01

This report summarizes the results of various experimental programs regarding the performance of thermal igniters for the deliberate ignition of hydrogen in light water reactors. Experiments involving both premixed combustion and combustion with continuous hydrogen injection are reviewed. Combustion characteristics examined include flammability limits of hydrogen:air and hydrogen:air:steam mixtures, combustion pressure rises, combustion completeness, flame speeds, and heat transfer aspects. Comparisons of igniter type and igniter reliability under simulated reactor accident conditions are included. The results of the research programs provide a broad data base covering nearly all aspects of hydrogen combustion related to the performance of deliberate ignition systems

DNS Study of the Ignition of n-Heptane Fuel Spray under HCCI Conditions

Science.gov (United States)

Wang, Yunliang; Rutland, Christopher J.

2004-11-01

Direct numerical simulations are carried out to investigate the mixing and auto-ignition processes of n-heptane fuel spray in a turbulent field using a skeletal chemistry mechanism with 44 species and 112 reactions. For the solution of the carrier gas fluid, we use the Eulerian method, while for the fuel spray, the Lagrangian method is used. We use an eighth-order finite difference scheme to calculate spacial derivatives and a fourth-order Runge-Kutta scheme for the time integration. The initial gas temperature is 926 K and the initial gas pressure is 30 atmospheres. The initial global equivalence ratio based on the fuel concentration is around 0.4. The initial droplet diameter is 60 macrons and the droplet temperature is 300 K. Evolutions of averaged temperature, species mass fraction, heat release and reaction rate are presented. Contours of temperature and species mass fractions are presented. The objective is to understand the mechanism of ignition under Homogeneous Charged Compression Ignition (HCCI) conditions, aiming at providing some useful information of HCCI combustion, which is one of the critical issues to be resolved.

The National Ignition Facility Project

International Nuclear Information System (INIS)

Paisner, J.A.; Campbell, E.M.; Hogan, W.J.

1994-01-01

The mission of the National Ignition Facility is to achieve ignition and gain in ICF targets in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effect testing, and for civilian applications such as fusion energy development and fundamental studies of matter at high temperatures and densities. This paper reviews the design, schedule and costs associated with the construction project

EUROPEAN ENERGY INTERCONNECTION EFFECTS ON THE ROMANIAN ECONOMY

Directory of Open Access Journals (Sweden)

Ionescu Mihaela

2014-07-01

Full Text Available In this paper the author wants to exemplify the extent to which economic growth in Romania is influenced by the current power system infrastructure investments in Europe. Electricity transmission infrastructure in Romania is at a turning point. The high level of security of supply, delivery efficiency in a competitive internal market are dependent on significant investment, both within the country and across borders. Since the economic crisis makes investment financing is increasingly difficult, it is necessary that they be targeted as well. The European Union has initiated the “Connecting Europe” through which investments are allocated to European energy network interconnection of energy. The action plan for this strategy will put a greater emphasis on investments that require hundreds of billions of euro in new technologies, infrastructure, improve energy intensity, low carbon energy technologies. Romania's energy challenge will depend on the new interconnection modern and smart, both within the country and other European countries, energy saving practices and technologies. This challenge is particularly important as Romania has recovered severe gaps in the level of economic performance compared to developed countries. Such investment will have a significant impact on transmission costs, especially electricity, while network tariffs will rise slightly. Some costs will be higher due to support programs in renewable energy nationwide.Measures are more economically sustainable to maintain or even reinforce the electricity market, which system can be flexible in order to address any issues of adequacy. These measures include investments in border infrastructure (the higher the network, so it is easier to evenly distribute energy from renewable sources, to measure demand response and energy storage solutions.An integrated European infrastructure will ensure economic growth in countries interconnected and thus Romania. Huge energy potential of

Preparing tomorrow's network today: RTE at the crossroads of the European electricity system. Cross-border electricity interconnections Key issues and figures - 2014 Edition

International Nuclear Information System (INIS)

2014-10-01

The interconnected electricity transmission network is a key element for ensuring security of supply, the creation of a single market and the integration of renewable energies. RTE and its European partners provide strengthened coordination by the use of interconnections to ensure solidarity between European countries. Interconnections also allow an electricity supplier to sell its energy to a customer located in another country in Europe. They contribute on a European scale to optimising the use of production means and in particular the integration of variable renewable energies. RTE, within the EnTSo-E (European Network of Transmission System Operators for Electricity), contributes to the publication of a common vision of the future of networks by 2030. The needs for new interconnection capacity are identified in the ten-year European network development plan (TYnDP) on the basis of a cost-benefit analysis. France is interconnected to all its neighbours via many cross-border links. However interconnection capacity with the various countries and its use differ widely. The usage profile of the interconnections is specific to each border and varies according to: - the characteristics of the production mix of each country, and in particular the level of production of renewable energies. - the level of consumption, which depends on the season, the type of day (working or non-working) the time of day, etc. - import and export capacity, which may be different depending on the internal constraints of the networks of each country

A trial of ignition innovation of gasoline engine by nanosecond pulsed low temperature plasma ignition

International Nuclear Information System (INIS)

Shiraishi, Taisuke; Urushihara, Tomonori; Gundersen, Martin

2009-01-01

Application of nanosecond pulsed low temperature plasma as an ignition technique for automotive gasoline engines, which require a discharge under conditions of high back pressure, has been studied experimentally using a single-cylinder engine. The nanosecond pulsed plasma refers to the transient (non-equilibrated) phase of a plasma before the formation of an arc discharge; it was obtained by applying a high voltage with a nanosecond pulse (FWHM of approximately 80 or 25 ns) between coaxial cylindrical electrodes. It was confirmed that nanosecond pulsed plasma can form a volumetric multi-channel streamer discharge at an energy consumption of 60 mJ cycle -1 under a high back pressure of 1400 kPa. It was found that the initial combustion period was shortened compared with the conventional spark ignition. The initial flame visualization suggested that the nanosecond pulsed plasma ignition results in the formation of a spatially dispersed initial flame kernel at a position of high electric field strength around the central electrode. It was observed that the electric field strength in the air gap between the coaxial cylindrical electrodes was increased further by applying a shorter pulse. It was also clarified that the shorter pulse improved ignitability even further.

A trial of ignition innovation of gasoline engine by nanosecond pulsed low temperature plasma ignition

Science.gov (United States)

Shiraishi, Taisuke; Urushihara, Tomonori; Gundersen, Martin

2009-07-01

Application of nanosecond pulsed low temperature plasma as an ignition technique for automotive gasoline engines, which require a discharge under conditions of high back pressure, has been studied experimentally using a single-cylinder engine. The nanosecond pulsed plasma refers to the transient (non-equilibrated) phase of a plasma before the formation of an arc discharge; it was obtained by applying a high voltage with a nanosecond pulse (FWHM of approximately 80 or 25 ns) between coaxial cylindrical electrodes. It was confirmed that nanosecond pulsed plasma can form a volumetric multi-channel streamer discharge at an energy consumption of 60 mJ cycle-1 under a high back pressure of 1400 kPa. It was found that the initial combustion period was shortened compared with the conventional spark ignition. The initial flame visualization suggested that the nanosecond pulsed plasma ignition results in the formation of a spatially dispersed initial flame kernel at a position of high electric field strength around the central electrode. It was observed that the electric field strength in the air gap between the coaxial cylindrical electrodes was increased further by applying a shorter pulse. It was also clarified that the shorter pulse improved ignitability even further.

Direct electrical arc ignition of hybrid rocket motors

Science.gov (United States)

Judson, Michael I., Jr.

Hybrid rockets motors provide distinct safety advantages when compared to traditional liquid or solid propellant systems, due to the inherent stability and relative inertness of the propellants prior to established combustion. As a result of this inherent propellant stability, hybrid motors have historically proven difficult to ignite. State of the art hybrid igniter designs continue to require solid or liquid reactants distinct from the main propellants. These ignition methods however, reintroduce to the hybrid propulsion system the safety and complexity disadvantages associated with traditional liquid or solid propellants. The results of this study demonstrate the feasibility of a novel direct electrostatic arc ignition method for hybrid motors. A series of small prototype stand-alone thrusters demonstrating this technology were successfully designed and tested using Acrylonitrile Butadiene Styrene (ABS) plastic and Gaseous Oxygen (GOX) as propellants. Measurements of input voltage and current demonstrated that arc-ignition will occur using as little as 10 watts peak power and less than 5 joules total energy. The motor developed for the stand-alone small thruster was adapted as a gas generator to ignite a medium-scale hybrid rocket motor using nitrous oxide /and HTPB as propellants. Multiple consecutive ignitions were performed. A large data set as well as a collection of development `lessons learned' were compiled to guide future development and research. Since the completion of this original groundwork research, the concept has been developed into a reliable, operational igniter system for a 75mm hybrid motor using both gaseous oxygen and liquid nitrous oxide as oxidizers. A development map of the direct spark ignition concept is presented showing the flow of key lessons learned between this original work and later follow on development.

Büroo Ignite = Ignite office / Priit Põldme, Reet Sepp

Index Scriptorium Estoniae

Põldme, Priit, 1971-

2013-01-01

Büroo Ignite (Tatari 25, Tallinn) sisekujundusest. Sisearhitektid Priit Põldme ja Reet Sepp (SAB Joonprojekt). Arhitektid Heiki Taras ja Ahti Luhaäär (Arhitektibüroo Pilter ja Taras). Sisearhitekti ja ESLi aastapreemiate žürii esimehe Kaido Kivi arvamus

High-resolution 3D simulations of NIF ignition targets performed on Sequoia with HYDRA

Science.gov (United States)

Marinak, M. M.; Clark, D. S.; Jones, O. S.; Kerbel, G. D.; Sepke, S.; Patel, M. V.; Koning, J. M.; Schroeder, C. R.

2015-11-01

Developments in the multiphysics ICF code HYDRA enable it to perform large-scale simulations on the Sequoia machine at LLNL. With an aggregate computing power of 20 Petaflops, Sequoia offers an unprecedented capability to resolve the physical processes in NIF ignition targets for a more complete, consistent treatment of the sources of asymmetry. We describe modifications to HYDRA that enable it to scale to over one million processes on Sequoia. These include new options for replicating parts of the mesh over a subset of the processes, to avoid strong scaling limits. We consider results from a 3D full ignition capsule-only simulation performed using over one billion zones run on 262,000 processors which resolves surface perturbations through modes l = 200. We also report progress towards a high-resolution 3D integrated hohlraum simulation performed using 262,000 processors which resolves surface perturbations on the ignition capsule through modes l = 70. These aim for the most complete calculations yet of the interactions and overall impact of the various sources of asymmetry for NIF ignition targets. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

The Interconnections of the LHC Cryomagnets

CERN Document Server

Jacquemod, A; Skoczen, Blazej; Tock, J P

2001-01-01

The main components of the LHC, the next world-class facility in high-energy physics, are the twin-aperture high-field superconducting cryomagnets to be installed in the existing 26.7-km long tunnel. After installation and alignment, the cryomagnets have to be interconnected. The interconnections must ensure the continuity of several functions: vacuum enclosures, beam pipe image currents (RF contacts), cryogenic circuits, electrical power supply, and thermal insulation. In the machine, about 1700 interconnections between cryomagnets are necessary. The interconnections constitute a unique system that is nearly entirely assembled in the tunnel. For each of them, various operations must be done: TIG welding of cryogenic channels (~ 50 000 welds), induction soldering of main superconducting cables (~ 10 000 joints), ultrasonic welding of auxiliary superconducting cables (~ 20 000 welds), mechanical assembly of various elements, and installation of the multi-layer insulation (~ 200 000 m2). Defective junctions cou...

Epidemics in interconnected small-world networks.

Science.gov (United States)

Liu, Meng; Li, Daqing; Qin, Pengju; Liu, Chaoran; Wang, Huijuan; Wang, Feilong

2015-01-01

Networks can be used to describe the interconnections among individuals, which play an important role in the spread of disease. Although the small-world effect has been found to have a significant impact on epidemics in single networks, the small-world effect on epidemics in interconnected networks has rarely been considered. Here, we study the susceptible-infected-susceptible (SIS) model of epidemic spreading in a system comprising two interconnected small-world networks. We find that the epidemic threshold in such networks decreases when the rewiring probability of the component small-world networks increases. When the infection rate is low, the rewiring probability affects the global steady-state infection density, whereas when the infection rate is high, the infection density is insensitive to the rewiring probability. Moreover, epidemics in interconnected small-world networks are found to spread at different velocities that depend on the rewiring probability.

Epidemics in interconnected small-world networks.

Directory of Open Access Journals (Sweden)

Meng Liu

Full Text Available Networks can be used to describe the interconnections among individuals, which play an important role in the spread of disease. Although the small-world effect has been found to have a significant impact on epidemics in single networks, the small-world effect on epidemics in interconnected networks has rarely been considered. Here, we study the susceptible-infected-susceptible (SIS model of epidemic spreading in a system comprising two interconnected small-world networks. We find that the epidemic threshold in such networks decreases when the rewiring probability of the component small-world networks increases. When the infection rate is low, the rewiring probability affects the global steady-state infection density, whereas when the infection rate is high, the infection density is insensitive to the rewiring probability. Moreover, epidemics in interconnected small-world networks are found to spread at different velocities that depend on the rewiring probability.

A Study on Fire Ignition Frequency of UCN 3 during Shutdown

International Nuclear Information System (INIS)

Kim, Kilyoo; Kang, DaeIl; Jang, Seung-Cheol

2014-01-01

A fire ignition frequency of UCN 3 during shutdown, i.e., during POS 3, 4, 5, 6 was calculated by using the new fire PSA method suggested in NUREG/CR-7114. As the fire ignition frequency during full power is calculated by the fixed ignition source and the transient ignition source, the one during shutdown is also calculated by the fixed and the transient ignition source. Since the fixed ignition source was already verified through the walkdown although the walkdown is for the fixed ignition source during full power, additional walkdown for the one during shutdown is not necessary. In the paper, how the fire ignition frequency of UCN 3 during shutdown was calculated is described. A fire ignition frequency of UCN 3 during shutdown, i.e., during POS 3, 4, 5, 6 was calculated by using the new fire PSA method suggested in NUREG/CR-7114. We make the transient ignition fire frequency of each BIN vary according to the daily work order of each POS

Solar-cell interconnect design for terrestrial photovoltaic modules

Science.gov (United States)

Mon, G. R.; Moore, D. M.; Ross, R. G., Jr.

1984-01-01

Useful solar cell interconnect reliability design and life prediction algorithms are presented, together with experimental data indicating that the classical strain cycle (fatigue) curve for the interconnect material does not account for the statistical scatter that is required in reliability predictions. This shortcoming is presently addressed by fitting a functional form to experimental cumulative interconnect failure rate data, which thereby yields statistical fatigue curves enabling not only the prediction of cumulative interconnect failures during the design life of an array field, but also the quantitative interpretation of data from accelerated thermal cycling tests. Optimal interconnect cost reliability design algorithms are also derived which may allow the minimization of energy cost over the design life of the array field.

Assessing the prospects for achieving double-shell ignition on the National Ignition Facility using vacuum hohlraums

Science.gov (United States)

Amendt, Peter

2006-10-01

The goal of demonstrating ignition on the National Ignition Facility (NIF) has motivated a revisit of double-shell (DS) [1] targets as a complementary path to the baseline cryogenic single-shell approach [2]. Benefits of DS targets include room-temperature deuterium-tritium (DT) fuel preparation, minimal hohlraum-plasma-mediated laser backscatter, low threshold-ignition temperatures (4 keV) for relaxed hohlraum x-ray flux asymmetry tolerances [3], and loose shock timing requirements. On the other hand, DS ignition presents several challenges, including room-temperature containment of high-pressure DT (790 atm) in the inner shell; strict concentricity requirements on the two shells; development of nanoporous, low-density, metallic foams for structural support of the inner shell and hydrodynamic instability mitigation; and effective control of perturbation growth on the high-Atwood number interface between the DT fuel and the high-Z inner shell. Recent progress in DS ignition target designs using vacuum hohlraums is described, offering the potential for low levels of laser backscatter from stimulated Raman and Brillouin processes. In addition, vacuum hohlraums have the operational advantages of room temperature fielding and fabrication simplicity, as well as benefiting from extensive benchmarking on the Nova and Omega laser facilities. As an alternative to standard cylindrical hohlraums, a rugby-shaped geometry is also introduced that may provide energetics and symmetry tuning benefits for more robust DS designs with yields exceeding 10 MJ for 2 MJ of 3w laser energy. The recent progress in hohlraum designs and required advanced materials development are scheduled to culminate in a prototype demonstration of a NIF-scale ignition-ready DS in 2007. [1] P. Amendt et al., PoP 9, 2221 (2002). [2] J.D. Lindl et al., PoP 11, 339 (2004). [3] M.N. Chizhkov et al., Laser Part. Beams 23, 261 (2005). In collaboration with C. Cerjan, A. Hamza, J. Milovich and H. Robey.

Self-Rerouting and Curative Interconnect Technology (SERCUIT)

Science.gov (United States)

2017-12-01

SPECIAL REPORT RDMR-CS-17-01 SELF-REROUTING AND CURATIVE INTERCONNECT TECHNOLOGY (SERCUIT) Shiv Joshi Concepts to Systems, Inc...Final 4. TITLE AND SUBTITLE Self-Rerouting and Curative Interconnect Technology (SERCUIT) 5. FUNDING NUMBERS 6. AUTHOR(S) Shiv Joshi...concepts2systems.com (p) 434-207-5189 x (f) Click to view full size Title Contract Number SELF-REROUTING AND CURATIVE INTERCONNECT TECHNOLOGY (SERCUIT) W911W6-17-C-0029

Network interconnections: an architectural reference model

NARCIS (Netherlands)

Butscher, B.; Lenzini, L.; Morling, R.; Vissers, C.A.; Popescu-Zeletin, R.; van Sinderen, Marten J.; Heger, D.; Krueger, G.; Spaniol, O.; Zorn, W.

1985-01-01

One of the major problems in understanding the different approaches in interconnecting networks of different technologies is the lack of reference to a general model. The paper develops the rationales for a reference model of network interconnection and focuses on the architectural implications for

A proposed holistic approach to on-chip, off-chip, test, and package interconnections

Science.gov (United States)

Bartelink, Dirk J.

1998-11-01

The term interconnection has traditionally implied a `robust' connection from a transistor or a group of transistors in an IC to the outside world, usually a PC board. Optimum system utilization is done from outside the IC. As an alternative, this paper addresses `unimpeded' transistor-to-transistor interconnection aimed at reaching the high circuit densities and computational capabilities of neighboring IC's. In this view, interconnections are not made to some human-centric place outside the IC world requiring robustness—except for system input and output connections. This unimpeded interconnect style is currently available only through intra-chip signal traces in `system-on-a-chip' implementations, as exemplified by embedded DRAMs. Because the traditional off-chip penalty in performance and wiring density is so large, a merging of complex process technologies is the only option today. It is suggested that, for system integration to move forward, the traditional robustness requirement inherited from conventional packaging interconnect and IC manufacturing test must be discarded. Traditional system assembly from vendor parts requires robustness under shipping, inspection and assembly. The trend toward systems on a chip signifies willingness by semiconductor companies to design and fabricate whole systems in house, so that `in-house' chip-to-chip assembly is not beyond reach. In this scenario, bare chips never leave the controlled environment of the IC fabricator while the two major contributors to off-chip signal penalty, ESD protection and the need to source a 50-ohm test head, are avoided. With in-house assembly, ESD protection can be eliminated with the precautions already familiar in plasma etching. Test interconnection impacts the fundamentals of IC manufacturing, particularly with clock speeds approaching 1GHz, and cannot be an afterthought. It should be an integral part of the chip-to-chip interconnection bandwidth optimization, because—as we must

TOPICAL REVIEW: Plasma assisted ignition and combustion

Science.gov (United States)

Starikovskaia, S. M.

2006-08-01

In recent decades particular interest in applications of nonequilibrium plasma for the problems of plasma-assisted ignition and plasma-assisted combustion has been observed. A great amount of experimental data has been accumulated during this period which provided the grounds for using low temperature plasma of nonequilibrium gas discharges for a number of applications at conditions of high speed flows and also at conditions similar to automotive engines. The paper is aimed at reviewing the data obtained and discusses their treatment. Basic possibilities of low temperature plasma to ignite gas mixtures are evaluated and historical references highlighting pioneering works in the area are presented. The first part of the review discusses plasmas applied to plasma-assisted ignition and combustion. The paper pays special attention to experimental and theoretical analysis of some plasma parameters, such as reduced electric field, electron density and energy branching for different gas discharges. Streamers, pulsed nanosecond discharges, dielectric barrier discharges, radio frequency discharges and atmospheric pressure glow discharges are considered. The second part depicts applications of discharges to reduce the ignition delay time of combustible mixtures, to ignite transonic and supersonic flows, to intensify ignition and to sustain combustion of lean mixtures. The results obtained by different authors are cited, and ways of numerical modelling are discussed. Finally, the paper draws some conclusions on the main achievements and prospects of future investigations in the field.

Ignition of an organic water-coal fuel droplet floating in a heated-air flow

Science.gov (United States)

Valiullin, T. R.; Strizhak, P. A.; Shevyrev, S. A.; Bogomolov, A. R.

2017-01-01

Ignition of an organic water-coal fuel (CWSP) droplet floating in a heated-air flow has been studied experimentally. Rank B2 brown-coal particles with a size of 100 μm, used crankcase Total oil, water, and a plasticizer were used as the main CWSP components. A dedicated quartz-glass chamber has been designed with inlet and outlet elements made as truncated cones connected via a cylindrical ring. The cones were used to shape an oxidizer flow with a temperature of 500-830 K and a flow velocity of 0.5-5.0 m/s. A technique that uses a coordinate-positioning gear, a nichrome thread, and a cutter element has been developed for discharging CWSP droplets into the working zone of the chamber. Droplets with an initial size of 0.4 to 2.0 mm were used. Conditions have been determined for a droplet to float in the oxidizer flow long enough for the sustainable droplet burning to be initiated. Typical stages and integral ignition characteristics have been established. The integral parameters (ignition-delay times) of the examined processes have been compared to the results of experiments with CWSP droplets suspended on the junction of a quick-response thermocouple. It has been shown that floating fuel droplets ignite much quicker than the ones that sit still on the thermocouple due to rotation of an CWSP droplet in the oxidizer flow, more uniform heating of the droplet, and lack of heat drainage towards the droplet center. High-speed video recording of the peculiarities of floatation of a burning fuel droplet makes it possible to complement the existing models of water-coal fuel burning. The results can be used for a more substantiated modeling of furnace CWSP burning with the ANSYS, Fluent, and Sigma-Flow software packages.

Advanced ignition for automotive engines

OpenAIRE

Pineda, Daniel Ivan

2017-01-01

Spark plugs have been igniting combustible mixtures like those found in automotive engines for over a century, and the principles of the associated ignition techniques using thermal plasma (inductive or capacitive sparks) have remained relatively unchanged during that time. However, internal combustion engines are increasingly operating with boosted intake pressures (i.e. turbo- or super-charged) in order to maintain power output while simultaneously reducing engine size and weight, and they ...

The National Ignition Facility Project

International Nuclear Information System (INIS)

Paisner, J.A.; Campbell, E.M.; Hogan, W.J.

1994-01-01

The mission of the National Ignition Facility is to achieve ignition and gain in inertial confinement fusion targets in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effects testing, and for civilian applications such as fusion energy development and fundamental studies of matter at high temperatures and densities. This paper reviews the design, schedule, and costs associated with the construction project

Fast ignition: Physics progress in the US fusion energy program and prospects for achieving ignition

International Nuclear Information System (INIS)

Key, M.; Andersen, C.; Cowan, T.

2003-01-01

Fast ignition (FI) has significant potential advantages for inertial fusion energy and it is therefore being studied as an exploratory concept in the US fusion energy program. FI is based on short pulse isochoric heating of pre-compressed DT by intense beams of laser accelerated MeV electrons or protons. Recent experimental progress in the study of these two heating processes is discussed. The goal is to benchmark new models in order to predict accurately the requirements for full-scale fast ignition. An overview is presented of the design and experimental testing of a cone target implosion concept for fast ignition. Future prospects and conceptual designs for larger scale FI experiments using planned high energy petawatt upgrades of major lasers in the US are outlined. A long-term road map for FI is defined. (author)

Ignition studies of two low-octane gasolines

KAUST Repository

Javed, Tamour

2017-07-24

Low-octane gasolines (RON ∼ 50–70 range) are prospective fuels for gasoline compression ignition (GCI) internal combustion engines. GCI technology utilizing low-octane fuels has the potential to significantly improve well-to-wheel efficiency and reduce the transportation sector\\'s environmental footprint by offsetting diesel fuel usage in compression ignition engines. In this study, ignition delay times of two low-octane FACE (Fuels for Advanced Combustion Engines) gasolines, FACE I and FACE J, were measured in a shock tube and a rapid compression machine over a broad range of engine-relevant conditions (650–1200 K, 20 and 40 bar and ϕ = 0.5 and 1). The two gasolines are of similar octane ratings with anti-knock index, AKI = (RON + MON)/2, of ∼ 70 and sensitivity, S = RON–MON, of ∼ 3. However, the molecular compositions of the two gasolines are notably different. Experimental ignition delay time results showed that the two gasolines exhibited similar reactivity over a wide range of test conditions. Furthermore, ignition delay times of a primary reference fuel (PRF) surrogate (n-heptane/iso-octane blend), having the same AKI as the FACE gasolines, captured the ignition behavior of these gasolines with some minor discrepancies at low temperatures (T < 700 K). Multi-component surrogates, formulated by matching the octane ratings and compositions of the two gasolines, emulated the autoignition behavior of gasolines from high to low temperatures. Homogeneous charge compression ignition (HCCI) engine simulations were used to show that the PRF and multi-component surrogates exhibited similar combustion phasing over a wide range of engine operating conditions.

Nano/CMOS architectures using a field-programmable nanowire interconnect

International Nuclear Information System (INIS)

Snider, Gregory S; Williams, R Stanley

2007-01-01

A field-programmable nanowire interconnect (FPNI) enables a family of hybrid nano/CMOS circuit architectures that generalizes the CMOL (CMOS/molecular hybrid) approach proposed by Strukov and Likharev, allowing for simpler fabrication, more conservative process parameters, and greater flexibility in the choice of nanoscale devices. The FPNI improves on a field-programmable gate array (FPGA) architecture by lifting the configuration bit and associated components out of the semiconductor plane and replacing them in the interconnect with nonvolatile switches, which decreases both the area and power consumption of the circuit. This is an example of a more comprehensive strategy for improving the efficiency of existing semiconductor technology: placing a level of intelligence and configurability in the interconnect can have a profound effect on integrated circuit performance, and can be used to significantly extend Moore's law without having to shrink the transistors. Compilation of standard benchmark circuits onto FPNI chip models shows reduced area (8 x to 25 x), reduced power, slightly lower clock speeds, and high defect tolerance-an FPNI chip with 20% defective junctions and 20% broken nanowires has an effective yield of 75% with no significant slowdown along the critical path, compared to a defect-free chip. Simulations show that the density and power improvements continue as both CMOS and nano fabrication parameters scale down, although the maximum clock rate decreases due to the high resistance of very small (<10 nm) metallic nanowires

Epidemics in interconnected small-world networks

NARCIS (Netherlands)

Liu, M.; Li, D.; Qin, P.; Liu, C.; Wang, H.; Wang, F.

2015-01-01

Networks can be used to describe the interconnections among individuals, which play an important role in the spread of disease. Although the small-world effect has been found to have a significant impact on epidemics in single networks, the small-world effect on epidemics in interconnected networks

Surface ignition behaviors of methane–air mixture in a gas oven burner

International Nuclear Information System (INIS)

Ryu, Jungwan; Kwon, Jongseo; Kim, Ryanggyun; Kim, Minseong; Kim, Youngsoo; Jeon, Chunghwan; Song, Juhun

2014-01-01

In a gas oven burner, commonly used as a residential appliance, a surface igniter is a critical component for creating a pilot flame near the surface that can propagate safely back to the nozzle of the burner. The igniter should meet critical operating requirements: a lower surface temperature needed to ignite a methane–air mixture and a stable/safe ignition sustained. Otherwise, such failure would result in an instantaneous peak in carbon monoxide emission and a safety hazard inside a closed oven. Several theoretical correlations have been used to predict ignition temperature as well as the critical ignition/extinction limit for a stagnation flow ignition. However, there have only been a few studies on ignition modes or relevant stability analysis, and therefore a more detailed examination of the transient ignition process is required. In this study, a high-speed flame visualization technique with temperature measurement was employed to reveal a surface ignition phenomenon and subsequent flame propagation of a cold combustible methane–air mixture in a gas oven burner. The operating parameters were the temperature–time history of the igniter surface, mixture velocity, and the distance of the igniter from the nozzle. The surface ignition temperatures were analyzed for such parameters under a safe ignition mode, while several abnormal modes leading to ignition failure were also recognized. - Highlights: •We revealed a surface ignition behavior of combustible mixture in gas oven burner. •We employed a flame visualization technique with temperature measurement. •We evaluated effects of parameters such as lifetime, mixture velocity and igniter distance. •We recognized several abnormal modes leading to ignition failure

Radiative Ignition of fine-ammonium perchlorate composite propellants

Energy Technology Data Exchange (ETDEWEB)

Cain, Jeremy; Brewster, M. Quinn [Department of Mechanical Science and Industrial Engineering, University of Illinois, Urbana, IL 61801 (United States)

2006-08-15

Radiative ignition of quasi-homogeneous mixtures of ammonium perchlorate (AP) and hydroxyterminated polybutadiene (HTPB) binder has been investigated experimentally. Solid propellants consisting of fine AP (2 {mu}m) and HTPB binder ({proportional_to}76/24% by mass) were ignited by CO{sub 2} laser radiation. The lower boundary of a go/no-go ignition map (minimum ignition time vs. heat flux) was obtained. Opacity was varied by adding carbon black up to 1% by mass. Ignition times ranged from 0.78 s to 0.076 s for incident fluxes ranging from 60 W/cm{sup 2} to 400 W/cm{sup 2}. It was found that AP and HTPB are sufficiently strongly absorbing of 10.6 {mu}m CO{sub 2} laser radiation (absorption coefficient {approx}250 cm{sup -1}) so that the addition of carbon black in amounts typical of catalysts or opacitymodifying agents (up to 1%) would have only a small influence on radiative ignition times at 10.6 {mu}m. A simple theoretical analysis indicated that the ignition time-flux data are consistent with in-depth absorption effects. Furthermore, this analysis showed that the assumption of surface absorption is not appropriate, even for this relatively opaque system. For broadband visible/near-infrared radiation, such as from burning metal/oxide particle systems, the effects of in-depth absorption would probably be even stronger. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

76 FR 39870 - PJM Interconnection, LLC; PJM Power Providers Group v. PJM Interconnection, LLC; Notice of Date...

Science.gov (United States)

2011-07-07

.... EL11-20-001] PJM Interconnection, LLC; PJM Power Providers Group v. PJM Interconnection, LLC; Notice of... Sell Offers for Planned Generation Capacity Resources submitted into PJM's Reliability Pricing Model... presents an opportunity to exercise buyer market power; (2) whether the Fixed Resource Requirement (FRR...

Ignition characteristics of coal blends in an entrained flow furnace

Energy Technology Data Exchange (ETDEWEB)

J. Faundez; B. Arias; F. Rubiera; A. Arenillas; X. Garcia; A.L. Gordon; J.J. Pis [Universidad de Concepcion, Concepcion (Chile)

2007-09-15

Ignition tests were carried out on blends of three coals of different rank - subbituminous, high volatile and low volatile bituminous - in two entrained flow reactors. The ignition temperatures were determined from the gas evolution profiles (CO, CO{sub 2}, NO, O{sub 2}), while the mechanism of ignition was elucidated from these profiles and corroborated by high-speed video recording. Under the experimental conditions of high carbon loading, clear interactive effects were observed for all the blends. Ignition of the lower rank coals (subbituminous, high volatile bituminous) enhanced the ignition of the higher rank coal (low volatile bituminous) in the blends. The ignition temperatures of the blends of the low rank coals (subbituminous-high volatile bituminous) were additive. However, for the rest of the blends the ignition temperatures were always closer to the lower rank coal in the blend. 21 refs., 8 figs.

Comprehensive study of ignition and combustion of single wooden particles

DEFF Research Database (Denmark)

Momenikouchaksaraei, Maryam; Yin, Chungen; Kær, Søren Knudsen

2013-01-01

How quickly large biomass particles can ignite and burn out when transported into a pulverized-fuel (pf) furnace and suddenly exposed to a hot gas flow containing oxygen is very important in biomass co-firing design and optimization. In this paper, the ignition and burnout of the largest possible...... for all the test conditions. As the particle is further heated up and the volume-weighted average temperature reaches the onset of rapid decomposition of hemicellulose and cellulose, a secondary homogeneous ignition occurs. The model-predicted ignition delays and burnout times show a good agreement...... with the experimental results. Homogeneous ignition delays are found to scale with specific surface areas while heterogeneous ignition delays show less dependency on the areas. The ignition and burnout are also affected by the process conditions, in which the oxygen concentration is found to have a more pronounced...

Electromigration of intergranular voids in metal films for microelectronic interconnects

CERN Document Server

Averbuch, A; Ravve, I

2003-01-01

Voids and cracks often occur in the interconnect lines of microelectronic devices. They increase the resistance of the circuits and may even lead to a fatal failure. Voids may occur inside a single grain, but often they appear on the boundary between two grains. In this work, we model and analyze numerically the migration and evolution of an intergranular void subjected to surface diffusion forces and external voltage applied to the interconnect. The grain-void interface is considered one-dimensional, and the physical formulation of the electromigration and diffusion model results in two coupled fourth-order one-dimensional time-dependent PDEs. The boundary conditions are specified at the triple points, which are common to both neighboring grains and the void. The solution of these equations uses a finite difference scheme in space and a Runge-Kutta integration scheme in time, and is also coupled to the solution of a static Laplace equation describing the voltage distribution throughout the grain. Since the v...

Results on 3D interconnection from AIDA WP3

Energy Technology Data Exchange (ETDEWEB)

Moser, Hans-Günther, E-mail: hgm@hll.mpg.de

2016-09-21

From 2010 to 2014 the EU funded AIDA project established in one of its work packages (WP3) a network of groups working collaboratively on advanced 3D integration of electronic circuits and semiconductor sensors for applications in particle physics. The main motivation came from the severe requirements on pixel detectors for tracking and vertexing at future Particle Physics experiments at LHC, super-B factories and linear colliders. To go beyond the state-of-the-art, the main issues were studying low mass, high bandwidth applications, with radiation hardness capabilities, with low power consumption, offering complex functionality, with small pixel size and without dead regions. The interfaces and interconnects of sensors to electronic readout integrated circuits are a key challenge for new detector applications.

Whist code calculations of ignition margin in an ignition tokamak

International Nuclear Information System (INIS)

Sheffield, J.

1985-01-01

A simple global model was developed to determine the ignition margin of tokamaks including electron and ion conduction losses. A comparison of this model with results from a 1 1/2 dimensional Whist code is made

The impact of increased interconnection on electricity systems with large penetrations of wind generation. A case study of Ireland and Great Britain

International Nuclear Information System (INIS)

Denny, E.; Tuohy, A.; Keane, A.; Flynn, D.; O'Malley, M.; Meibom, P.; Mullane, A.

2010-01-01

Increased interconnection has been highlighted as potentially facilitating the integration of wind generation in power systems by increasing the flexibility to balance the variable wind output. This paper utilizes a stochastic unit commitment model to simulate the impacts of increased interconnection for the island of Ireland with large penetrations of wind generation. The results suggest that increased interconnection should reduce average prices in Ireland, and the variability of those prices. The simulations also suggest that while increased interconnection may reduce carbon dioxide emissions in Ireland, Great Britain would experience an increase in emissions, resulting in total emissions remaining almost unchanged. The studies suggest that increased interconnection would not reduce excess wind generation. This is because under unit commitment techniques which incorporate wind power forecasts in the scheduling decisions, wind curtailment is minimal even with low levels of interconnection. As would be expected an increase in interconnection should improve system adequacy considerably with a significant reduction in the number of hours when the load and reserve constraints are not met. (author)

Ignition Delay of Combustible Materials in Normoxic Equivalent Environments

Science.gov (United States)

McAllister, Sara; Fernandez-Pello, Carlos; Ruff, Gary; Urban, David

2009-01-01

Material flammability is an important factor in determining the pressure and composition (fraction of oxygen and nitrogen) of the atmosphere in the habitable volume of exploration vehicles and habitats. The method chosen in this work to quantify the flammability of a material is by its ease of ignition. The ignition delay time was defined as the time it takes a combustible material to ignite after it has been exposed to an external heat flux. Previous work in the Forced Ignition and Spread Test (FIST) apparatus has shown that the ignition delay in the currently proposed space exploration atmosphere (approximately 58.6 kPa and32% oxygen concentration) is reduced by 27% compared to the standard atmosphere used in the Space Shuttle and Space Station. In order to determine whether there is a safer environment in terms of material flammability, a series of piloted ignition delay tests using polymethylmethacrylate (PMMA) was conducted in the FIST apparatus to extend the work over a range of possible exploration atmospheres. The exploration atmospheres considered were the normoxic equivalents, i.e. reduced pressure conditions with a constant partial pressure of oxygen. The ignition delay time was seen to decrease as the pressure was reduced along the normoxic curve. The minimum ignition delay observed in the normoxic equivalent environments was nearly 30% lower than in standard atmospheric conditions. The ignition delay in the proposed exploration atmosphere is only slightly larger than this minimum. Interms of material flammability, normoxic environments with a higher pressure relative to the proposed pressure would be desired.

Laser Ignition Technology for Bi-Propellant Rocket Engine Applications

Science.gov (United States)

Thomas, Matthew E.; Bossard, John A.; Early, Jim; Trinh, Huu; Dennis, Jay; Turner, James (Technical Monitor)

2001-01-01

The fiber optically coupled laser ignition approach summarized is under consideration for use in igniting bi-propellant rocket thrust chambers. This laser ignition approach is based on a novel dual pulse format capable of effectively increasing laser generated plasma life times up to 1000 % over conventional laser ignition methods. In the dual-pulse format tinder consideration here an initial laser pulse is used to generate a small plasma kernel. A second laser pulse that effectively irradiates the plasma kernel follows this pulse. Energy transfer into the kernel is much more efficient because of its absorption characteristics thereby allowing the kernel to develop into a much more effective ignition source for subsequent combustion processes. In this research effort both single and dual-pulse formats were evaluated in a small testbed rocket thrust chamber. The rocket chamber was designed to evaluate several bipropellant combinations. Optical access to the chamber was provided through small sapphire windows. Test results from gaseous oxygen (GOx) and RP-1 propellants are presented here. Several variables were evaluated during the test program, including spark location, pulse timing, and relative pulse energy. These variables were evaluated in an effort to identify the conditions in which laser ignition of bi-propellants is feasible. Preliminary results and analysis indicate that this laser ignition approach may provide superior ignition performance relative to squib and torch igniters, while simultaneously eliminating some of the logistical issues associated with these systems. Further research focused on enhancing the system robustness, multiplexing, and window durability/cleaning and fiber optic enhancements is in progress.

Effect of Temperature, Pressure and Equivalence Ratio on Ignition Delay in Ignition Quality Tester (IQT): Diesel,n-Heptane, andiso-Octane Fuels under Low Temperature Conditions

KAUST Repository

Yang, Seung Yeon

2015-11-02

Effects of temperature, pressure and global equivalence ratio on total ignition delay time in a constant volume spray combustion chamber were investigated for diesel fuel along with the primary reference fuels (PRFs) of n-heptane and iso-octane in relatively low temperature conditions to simulate unsteady spray ignition behavior. A KAUST Research ignition quality tester (KR-IQT) was utilized, which has a feature of varying temperature, pressure and equivalence ratio using a variable displacement fuel pump. A gradient method was adopted in determining the start of ignition in order to compensate pressure increase induced by low temperature heat release. Comparison of this method with other existing methods was discussed. Ignition delay times were measured at various equivalence ratios (0.5-1.7) with the temperatures of initial charge air in the range from 698 to 860 K and the pressures in the range of 1.5 to 2.1 MPa, pertinent to low temperature combustion (LTC) conditions. An attempt to scale the effect of pressure on total ignition delay was undertaken and the equivalence ratio exponent and activation energy in the Arrhenius expression of total ignition delay were determined. Ignition delay results indicated that there were strong correlations of pressure, temperature, and equivalence ratio under most conditions studied except at relatively low pressures. Diesel (DCN 52.5) and n-heptane (DCN 54) fuels exhibited reasonably similar ignition delay characteristics, while iso-octane showed a distinct behavior under low temperature regime having a two-stage ignition, which substantiate the adoption of the gradient method in determining ignition delay.

Crosstalk in modern on-chip interconnects a FDTD approach

CERN Document Server

Kaushik, B K; Patnaik, Amalendu

2016-01-01

The book provides accurate FDTD models for on-chip interconnects, covering most recent advancements in materials and design. Furthermore, depending on the geometry and physical configurations, different electrical equivalent models for CNT and GNR based interconnects are presented. Based on the electrical equivalent models the performance comparison among the Cu, CNT and GNR-based interconnects are also discussed in the book. The proposed models are validated with the HSPICE simulations. The book introduces the current research scenario in the modeling of on-chip interconnects. It presents the structure, properties, and characteristics of graphene based on-chip interconnects and the FDTD modeling of Cu based on-chip interconnects. The model considers the non-linear effects of CMOS driver as well as the transmission line effects of interconnect line that includes coupling capacitance and mutual inductance effects. In a more realistic manner, the proposed model includes the effect of width-dependent MFP of the ...

Ignition and burn propagation with suprathermal electron auxiliary heating

International Nuclear Information System (INIS)

Han Shensheng; Wu Yanqing

2000-01-01

The rapid development in ultrahigh-intensity lasers has allowed the exploration of applying an auxiliary heating technique in inertial confinement fusion (ICF) research. It is hoped that, compared with the 'standard fast ignition' scheme, raising the temperature of a hot-spot over the ignition threshold based on the shock-heated temperature will greatly reduce the required output energy of an ignition ultrahigh-intensity pulse. One of the key issues in ICF auxiliary heating is: how can we transport the exogenous energy efficiently into the hot-spot of compressed DT fuel? A scheme is proposed with three phases. First, a partial-spherical-shell capsule, such as double-conical target, is imploded as in the conventional approach to inertial fusion to assemble a high-density fuel configuration with a hot-spot of temperature lower than the ignition threshold. Second, a hole is bored through the shell outside the hot-spot by suprathermal electron explosion boring. Finally, the fuel is ignited by suprathermal electrons produced in the high-intensity ignition laser-plasma interactions. Calculations with a simple hybrid model show that the new scheme can possibly lead to ignition and burn propagation with a total drive energy of a few tens of kilojoules and an output energy as low as hundreds of joules for a single ignition ultrahigh-intensity pulse. (author)

Ignition of an overheated, underdense, fusioning tokamak plasma

International Nuclear Information System (INIS)

Singer, C.E.; Jassby, D.L.; Hovey, J.

1979-08-01

Methods of igniting an overheated but underdense D-T plasma core with a cold plasma blanket are investigated using a simple two-zone model with a variety of transport scaling laws, and also using a one-dimensional transport code. The power consumption of neutral-beam injectors required to produce ignition can be reduced significantly if the underdense core plasma is heated to temperatures much higher than the final equilibrium ignition values, followed by fueling from a cold plasma blanket. It is also found that the allowed impurity concentration in the initial hot core can be greater than normally permitted for ignition provided that the blanket is free from impurities

Linear induction accelerator requirements for ion fast ignition

International Nuclear Information System (INIS)

Logan, G.

1998-01-01

Fast ignition (fast heating of DT cores afief compression) reduces driver energy (by 10 X or more) by reducing the implosion velocity and energy for a given fuel compression ratio. For any type of driver that can deliver the ignition energy fast enough, fast ignition increases the target gain compared to targets using fast implosions for central ignition, as long as the energy to heat the core after compression is comparable to or less than the slow compression energy, and as long as the coupling efficiency of the fast ignitor beam to heat the core is comparable to the overall efficiency of compressing the core (in terms of beam energy-to-DT-efficiency). Ion driven fast ignition, compared to laser-driven fast ignition, has the advantage of direct (dE/dx) deposition of beam energy to the DT, eliminating inefficiencies for conversion into hot electrons, and direct ion heating also has a more favorable deposition profile with the Bragg-peak near the end of an ion range chosen to be deep inside a compressed DT core. While Petawatt laser experiments at LLNL have demonstrated adequate light-to-hot-electron conversion efficiency, it is not yet known if light and hot electrons can channel deeply enough to heat a small portion of a IOOOxLD compressed DT core to ignition. On the other hand, lasers with chirped-pulse amplification giving thousand-fold pulse compressions have been demonstrated to produce the short pulses, small focal spots and Petawatt peak powers approaching those required for fast ignition, whereas ion accelerators that can produce sufficient beam quality for similar compression ratios and focal spot sizes of ion bunches have not yet been demonstrated, where an imposed coherent velocity tilt plays the analogous role for beam compression as does frequency chirp with lasers. Accordingly, it is the driver technology, not the target coupling physics, that poses the main challenge to ion-driven fast ignition. As the mainline HIF program is concentrating on

Reactive power interconnection requirements for PV and wind plants : recommendations to NERC.

Energy Technology Data Exchange (ETDEWEB)

McDowell, Jason (General Electric, Schenectady, NY); Walling, Reigh (General Electric, Schenectady, NY); Peter, William (SunPower, Richmond, CA); Von Engeln, Edi (NV Energy, Reno, NV); Seymour, Eric (AEI, Fort Collins, CO); Nelson, Robert (Siemens Wind Turbines, Orlando, FL); Casey, Leo (Satcon, Boston, MA); Ellis, Abraham; Barker, Chris. (SunPower, Richmond, CA)

2012-02-01

Voltage on the North American bulk system is normally regulated by synchronous generators, which typically are provided with voltage schedules by transmission system operators. In the past, variable generation plants were considered very small relative to conventional generating units, and were characteristically either induction generator (wind) or line-commutated inverters (photovoltaic) that have no inherent voltage regulation capability. However, the growing level of penetration of non-traditional renewable generation - especially wind and solar - has led to the need for renewable generation to contribute more significantly to power system voltage control and reactive power capacity. Modern wind-turbine generators, and increasingly PV inverters as well, have considerable dynamic reactive power capability, which can be further enhanced with other reactive support equipment at the plant level to meet interconnection requirements. This report contains a set of recommendations to the North-America Electricity Reliability Corporation (NERC) as part of Task 1-3 (interconnection requirements) of the Integration of Variable Generation Task Force (IVGTF) work plan. The report discusses reactive capability of different generator technologies, reviews existing reactive power standards, and provides specific recommendations to improve existing interconnection standards.

Temperature analysis of laser ignited metalized material using spectroscopic technique

Science.gov (United States)

Bassi, Ishaan; Sharma, Pallavi; Daipuriya, Ritu; Singh, Manpreet

2018-05-01

The temperature measurement of the laser ignited aluminized Nano energetic mixture using spectroscopy has a great scope in in analysing the material characteristic and combustion analysis. The spectroscopic analysis helps to do in depth study of combustion of materials which is difficult to do using standard pyrometric methods. Laser ignition was used because it consumes less energy as compared to electric ignition but ignited material dissipate the same energy as dissipated by electric ignition and also with the same impact. Here, the presented research is primarily focused on the temperature analysis of energetic material which comprises of explosive material mixed with nano-material and is ignited with the help of laser. Spectroscopy technique is used here to estimate the temperature during the ignition process. The Nano energetic mixture used in the research does not comprise of any material that is sensitive to high impact.

Plasma position control in a tokamak reactor around ignition

International Nuclear Information System (INIS)

Carretta, U.; Minardi, E.; Bacelli, N.

1986-01-01

Plasma position control in a tokamak reactor in the phase approaching ignition is closely related to burn control. If ignited burn corresponds to a thermally unstable situation the plasma becomes sensitive to the thermal instability already in the phase when ignition is approached so that the trajectory in the position-pressure (R,p) space becomes effectively unpredictable. For example, schemes involving closed cycles around ignition can be unstable in the heating-cooling phases, and the deviations may be cumulative in time. Reliable plasma control in pressure-position (p, R) space is achieved by beforehand constraining the p, R trajectory rigidly with suitable feedback vertical field stabilization, which is to be established already below ignition. A scheme in which ignition is approached in a stable and automatic way by feedback stabilization on the vertical field is proposed and studied in detail. The values of the gain coefficient ensuring stabilization and the associated p and R excursions are discussed both analytically, with a 0-D approximation including non-linear effects, and numerically with a 1-D code in cylindrical geometry. Profile effects increase the excursions, in particular above ignition. (author)

Review of Interconnection Practices and Costs in the Western States

Energy Technology Data Exchange (ETDEWEB)

Bird, Lori A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Flores-Espino, Francisco [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Volpi, Christina M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ardani, Kristen B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Manning, David [Western Interstate Energy Board (WIEB); McAllister, Richard [Western Interstate Energy Board (WIEB)

2018-04-27

The objective of this report is to evaluate the nature of barriers to interconnecting distributed PV, assess costs of interconnection, and compare interconnection practices across various states in the Western Interconnection. The report addresses practices for interconnecting both residential and commercial-scale PV systems to the distribution system. This study is part of a larger, joint project between the Western Interstate Energy Board (WIEB) and the National Renewable Energy Laboratory (NREL), funded by the U.S. Department of Energy, to examine barriers to distributed PV in the 11 states wholly within the Western Interconnection.

Architecture-Level Exploration of Alternative Interconnection Schemes Targeting 3D FPGAs: A Software-Supported Methodology

Directory of Open Access Journals (Sweden)

Kostas Siozios

2008-01-01

Full Text Available In current reconfigurable architectures, the interconnection structures increasingly contribute more to the delay and power consumption. The demand for increased clock frequencies and logic density (smaller area footprint makes the problem even more important. Three-dimensional (3D architectures are able to alleviate this problem by accommodating a number of functional layers, each of which might be fabricated in different technology. However, the benefits of such integration technology have not been sufficiently explored yet. In this paper, we propose a software-supported methodology for exploring and evaluating alternative interconnection schemes for 3D FPGAs. In order to support the proposed methodology, three new CAD tools were developed (part of the 3D MEANDER Design Framework. During our exploration, we study the impact of vertical interconnection between functional layers in a number of design parameters. More specifically, the average gains in operation frequency, power consumption, and wirelength are 35%, 32%, and 13%, respectively, compared to existing 2D FPGAs with identical logic resources. Also, we achieve higher utilization ratio for the vertical interconnections compared to existing approaches by 8% for designing 3D FPGAs, leading to cheaper and more reliable devices.

Antiproton fast ignition for inertial confinement fusion

International Nuclear Information System (INIS)

Perkins, L.J.

1999-01-01

With 180 MJ/microg, antiprotons offer the highest stored energy per unit mass of any known entity. The use of antiprotons to promote fast ignition in an inertial confinement fusion (ICF) capsule and produce high target gains with only modest compression of the main fuel is investigated. Unlike standard fast ignition where the ignition energy is supplied by energetic, short pulse laser, the energy here is supplied through the ionization energy deposited when antiprotons annihilate at the center of a compressed fuel capsule. This can be considered in-situ fast ignition as it obviates the need for the external injection of the ignition energy. In the first of two candidate schemes, the antiproton package is delivered by a low-energy ion beam. In the second, autocatalytic scheme, the antiprotons are preemplaced at the center of the capsule prior to compression. In both schemes, the author estimates that ∼10 12 antiprotons are required to initiate fast ignition in a typical ICF capsule and show that incorporation of a thin, heavy metal shell is desirable to enhance energy deposition within the ignitor zone. In addition to eliminating the need for a second, energetic fast laser and vulnerable final optics, this scheme would achieve central ignition without reliance on laser channeling through halo plasma or Hohlraum debris. However, in addition to the practical difficulties of storage and manipulation of antiprotons at low energy, the other large uncertainty for the practicality of such a speculative scheme is the ultimate efficiency of antiproton production in an external, optimized facility. Estimates suggest that the electrical wall plug energy per pulse required for the separate production of the antiprotons is of the same order as that required for the conventional slow compression driver

Diagnosing ignition with DT reaction history

International Nuclear Information System (INIS)

Wilson, D. C.; Bradley, P. A.; Herrmann, H. W.; Cerjan, C. J.; Salmonson, J. D.; Spears, B. K.; Hatchet, S. P. II; Glebov, V. Yu.

2008-01-01

A full range DT reaction history of an ignition capsule, from 10 9 to 10 20 neutrons/ns, offers the opportunity to diagnose fuel conditions hundreds of picoseconds before and during burn. The burn history begins with a sharp rise when the first shock reaches the center of the capsule. The level of this jump reflects the combined shock strength and the adiabat of DT fuel. Changes to the four laser pulses driving the capsule implosion which are large enough to degrade the yield make measurable changes to the reaction history. Low mode asymmetries grow during convergence but change the reaction history during the final ∼100 ps. High mode asymmetry or turbulence mixing affects only the reaction history within ∼50 ps of peak burn rate. A capsule with a tritium fuel layer containing a small amount of deuterium (∼1%) creates a reaction history similar to the ignition capsule, but without the final ignition burn. A combination of gas Cerenkov detectors and the neutron temporal diagnostic could be capable of diagnosing the full history of ignition and tritium rich capsules.

Does charge transfer correlate with ignition probability?

International Nuclear Information System (INIS)

Holdstock, Paul

2008-01-01

Flammable or explosive atmospheres exist in many industrial environments. The risk of ignition caused by electrostatic discharges is very real and there has been extensive study of the incendiary nature of sparks and brush discharges. It is clear that in order to ignite a gas, an amount of energy needs to be delivered to a certain volume of gas within a comparatively short time. It is difficult to measure the energy released in an electrostatic discharge directly, but it is possible to approximate the energy in a spark generated from a well defined electrical circuit. The spark energy required to ignite a gas, vapour or dust cloud can be determined by passing such sparks through them. There is a relationship between energy and charge in a capacitive circuit and so it is possible to predict whether or not a spark discharge will cause an ignition by measuring the charge transferred in the spark. Brush discharges are in many ways less well defined than sparks. Nevertheless, some work has been done that has established a relationship between charge transferred in brush discharges and the probability of igniting a flammable atmosphere. The question posed by this paper concerns whether such a relationship holds true in all circumstances and if there is a universal correlation between charge transfer and ignition probability. Data is presented on discharges from textile materials that go some way to answering this question.

Dark Matter Ignition of Type Ia Supernovae.

Science.gov (United States)

Bramante, Joseph

2015-10-02

Recent studies of low redshift type Ia supernovae (SN Ia) indicate that half explode from less than Chandrasekhar mass white dwarfs, implying ignition must proceed from something besides the canonical criticality of Chandrasekhar mass SN Ia progenitors. We show that 1-100 PeV mass asymmetric dark matter, with imminently detectable nucleon scattering interactions, can accumulate to the point of self-gravitation in a white dwarf and collapse, shedding gravitational potential energy by scattering off nuclei, thereby heating the white dwarf and igniting the flame front that precedes SN Ia. We combine data on SN Ia masses with data on the ages of SN Ia-adjacent stars. This combination reveals a 2.8σ inverse correlation between SN Ia masses and ignition ages, which could result from increased capture of dark matter in 1.4 vs 1.1 solar mass white dwarfs. Future studies of SN Ia in galactic centers will provide additional tests of dark-matter-induced type Ia ignition. Remarkably, both bosonic and fermionic SN Ia-igniting dark matter also resolve the missing pulsar problem by forming black holes in ≳10  Myr old pulsars at the center of the Milky Way.

Physics aspects of the Compact Ignition Tokamak

International Nuclear Information System (INIS)

Post, D.; Bateman, G.; Houlberg, W.

1986-11-01

The Compact Ignition Tokamak (CIT) is a proposed modest-size ignition experiment designed to study the physics of alpha-particle heating. The basic concept is to achieve ignition in a modest-size minimum cost experiment by using a high plasma density to achieve the condition of ntau/sub E/ ∼ 2 x 10 20 sec m -3 required for ignition. The high density requires a high toroidal field (10 T). The high toroidal field allows a large plasma current (10 MA) which improves the energy confinement, and provides a high level of ohmic heating. The present CIT design also has a gigh degree of elongation (k ∼ 1.8) to aid in producing the large plasma current. A double null poloidal divertor and a pellet injector are part of the design to provide impurity and particle control, improve the confinement, and provide flexibility for impurity and particle control, improve the confinement, and provide flexibility for improving the plasma profiles. Since auxiliary heating is expected to be necessary to achieve ignition, 10 to 20 MW of Ion Cyclotron Radio Frequency (ICRF) is to be provided

The National Ignition Facility and Industry

Science.gov (United States)

Harri, J. G.; Paisner, J. A.; Lowdermilk, W. H.; Boyes, J. D.; Kumpan, S. A.; Sorem, M. S.

1994-09-01

The mission of the National Ignition Facility is to achieve ignition and gain in inertial confinement fusion targets in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effects testing, and for civilian applications such as fusion energy development and fundamental studies of matter at high temperatures and densities. The National Ignition Facility construction project will require the best of our construction industries and its success will depend on the best products offered by hundreds of the nation's high technology companies. Three-fourths of the construction costs will be invested in industry. This article reviews the design, cost and schedule, and required industrial involvement associated with the construction project.

The National Ignition Facility and industry

International Nuclear Information System (INIS)

Harri, J.G.; Lowdermilk, W.H.; Paisner, J.A.; Boyes, J.D.; Kumpan, S.A.; Sorem, M.S.

1994-01-01

The mission of the National Ignition Facility is to achieve ignition and gain in inertial confinement fusion targets in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effects testing, and for civilian applications such as fusion energy development and fundamental studies of matter at high temperatures and densities. The National Ignition Facility construction project will require the best of national construction industries and its success will depend on the best products offered by hundreds of the nation's high technology companies. Three-fourths of the construction costs will be invested in industry. This article reviews the design, cost and schedule, and required industrial involvement associated with the construction project

Ignition in the next step tokamak

International Nuclear Information System (INIS)

Johner, J.

1990-07-01

A 1/2-D model for thermal equilibrium of a thermonuclear plasma with transport described by an empirical global energy confinement time is described. Ignition in NET and ITER is studied for a number of energy confinement time scaling expressions. Ignited operation of these machines at the design value of the neutron wall load is shown to satisfy both beta and density constraints. The value of the confinement time enhancement factor required for such operation is found to be lower for the more recently proposed scaling expressions than it is for the oldest ones. With such new scalings, ignition could be obtained in H-mode in NET and ITER even with relatively flat density profiles

Tritium and ignition target management at the National Ignition Facility.

Science.gov (United States)

Draggoo, Vaughn

2013-06-01

Isotopic mixtures of hydrogen constitute the basic fuel for fusion targets of the National Ignition Facility (NIF). A typical NIF fusion target shot requires approximately 0.5 mmoles of hydrogen gas and as much as 750 GBq (20 Ci) of 3H. Isotopic mix ratios are specified according to the experimental shot/test plan and the associated test objectives. The hydrogen isotopic concentrations, absolute amounts, gas purity, configuration of the target, and the physical configuration of the NIF facility are all parameters and conditions that must be managed to ensure the quality and safety of operations. An essential and key step in the preparation of an ignition target is the formation of a ~60 μm thick hydrogen "ice" layer on the inner surface of the target capsule. The Cryogenic Target Positioning System (Cryo-Tarpos) provides gas handling, cyro-cooling, x-ray imaging systems, and related instrumentation to control the volumes and temperatures of the multiphase (solid, liquid, and gas) hydrogen as the gas is condensed to liquid, admitted to the capsule, and frozen as a single spherical crystal of hydrogen in the capsule. The hydrogen fuel gas is prepared in discrete 1.7 cc aliquots in the LLNL Tritium Facility for each ignition shot. Post-shot hydrogen gas is recovered in the NIF Tritium Processing System (TPS). Gas handling systems, instrumentation and analytic equipment, material accounting information systems, and the shot planning systems must work together to ensure that operational and safety requirements are met.

Development formulation of crafts weaving batik ikat East Java: Strategic block and interconnection

Directory of Open Access Journals (Sweden)

Didiek Tranggono

2015-08-01

Full Text Available Batik tenun ikat has been the traditional legacy in some areas of East Java. This research is based on the findings and analysis on batik tenun ikat in Kediri and Lamongan. The data were collected from observation, in depth-interview, and printed documentations. The SWOT analysis showed that batik tenun ikat in Kediri and Lamongan got the position number two (2. Thus, the priority strategies are 1 extending partnership, 2 diversification of products and 3 e-marketing and integrated one-web destination. In applying those strategies the need of implementation of strategic block and interconnection is inevitable. Strategic blocs and interconnection would deeply increased the connectivity among the actors and hence between the economic elements.

Performance metrics for Inertial Confinement Fusion implosions: aspects of the technical framework for measuring progress in the National Ignition Campaign

International Nuclear Information System (INIS)

Spears, B.K.; Glenzer, S.; Edwards, M.J.; Brandon, S.; Clark, D.; Town, R.; Cerjan, C.; Dylla-Spears, R.; Mapoles, E.; Munro, D.; Salmonson, J.; Sepke, S.; Weber, S.; Hatchett, S.; Haan, S.; Springer, P.; Moses, E.; Mapoles, E.; Munro, D.; Salmonson, J.; Sepke, S.

2011-01-01

The National Ignition Campaign (NIC) uses non-igniting 'THD' capsules to study and optimize the hydrodynamic assembly of the fuel without burn. These capsules are designed to simultaneously reduce DT neutron yield and to maintain hydrodynamic similarity with the DT ignition capsule. We will discuss nominal THD performance and the associated experimental observables. We will show the results of large ensembles of numerical simulations of THD and DT implosions and their simulated diagnostic outputs. These simulations cover a broad range of both nominal and off nominal implosions. We will focus on the development of an experimental implosion performance metric called the experimental ignition threshold factor (ITFX). We will discuss the relationship between ITFX and other integrated performance metrics, including the ignition threshold factor (ITF), the generalized Lawson criterion (GLC), and the hot spot pressure (HSP). We will then consider the experimental results of the recent NIC THD campaign. We will show that we can observe the key quantities for producing a measured ITFX and for inferring the other performance metrics. We will discuss trends in the experimental data, improvement in ITFX, and briefly the upcoming tuning campaign aimed at taking the next steps in performance improvement on the path to ignition on NIF.

Performance metrics for Inertial Confinement Fusion implosions: aspects of the technical framework for measuring progress in the National Ignition Campaign

Energy Technology Data Exchange (ETDEWEB)

Spears, B K; Glenzer, S; Edwards, M J; Brandon, S; Clark, D; Town, R; Cerjan, C; Dylla-Spears, R; Mapoles, E; Munro, D; Salmonson, J; Sepke, S; Weber, S; Hatchett, S; Haan, S; Springer, P; Moses, E; Mapoles, E; Munro, D; Salmonson, J; Sepke, S

2011-12-16

The National Ignition Campaign (NIC) uses non-igniting 'THD' capsules to study and optimize the hydrodynamic assembly of the fuel without burn. These capsules are designed to simultaneously reduce DT neutron yield and to maintain hydrodynamic similarity with the DT ignition capsule. We will discuss nominal THD performance and the associated experimental observables. We will show the results of large ensembles of numerical simulations of THD and DT implosions and their simulated diagnostic outputs. These simulations cover a broad range of both nominal and off nominal implosions. We will focus on the development of an experimental implosion performance metric called the experimental ignition threshold factor (ITFX). We will discuss the relationship between ITFX and other integrated performance metrics, including the ignition threshold factor (ITF), the generalized Lawson criterion (GLC), and the hot spot pressure (HSP). We will then consider the experimental results of the recent NIC THD campaign. We will show that we can observe the key quantities for producing a measured ITFX and for inferring the other performance metrics. We will discuss trends in the experimental data, improvement in ITFX, and briefly the upcoming tuning campaign aimed at taking the next steps in performance improvement on the path to ignition on NIF.

Influence of interface conditions on laser diode ignition of pyrotechnic mixtures: application to the design of an ignition device

Energy Technology Data Exchange (ETDEWEB)

Opdebeck, Frederic; Gillard, Philippe [Laboratoire Energetique Explosions et Structures de l' Universite d' Orleans, 63 boulevard de Lattre de Tassigny, 18020 cedex, Bourges (France); Radenac, D' Erwann [Laboratoire de combustion et de detonique, ENSMA, BP 109, 86960 cedex, Futuroscope (France)

2003-01-01

This paper treats of numerical modelling which simulates the laser ignition of pyrotechnic mixtures. The computation zone is divided into two fields. The first is used to take account of the heat loss with the outside. It can represent an optical fibre or a sapphire protective porthole. The second field represents the reactive tablet which absorbs the laser diode's beam. A specific feature of the model is that it incorporates a thermal contact resistance R{sub c} between the two computation fields. Through knowledge of the thermal, optical and kinetic properties, this code makes it possible to compute the ignition conditions. The latter are defined by the energy E{sub 50} and the time t{sub i} of ignition of any pyrotechnic mixture and for various ignition systems.This work was validated in the case of an ignition system consisting of a laser diode with an optical lens re-focussing system. The reactive tablet contains 62% by mass of iron and 38% by mass of KClO{sub 4}. Its porosity is 25.8%. After an evaluation of the laser's coefficient of absorption, the variations of the ignition parameters E{sub 50} and t{sub i} are studied as a function of the thermal contact resistance R{sub c}. Temperature profiles are obtained as a function of time and for various values of the thermal contact resistance R{sub c}. More fundamental observations are made concerning the position of the hot spot corresponding to priming. From this study, which concerns the heat exchange between the two media, several practical conclusions are given concerning the design of an ignition device. By evaluation of the thermal contact resistance R{sub c}, comparison with test results becomes possible and the results of the computations are in reasonable agreement with the test measurements. (authors)

Systems Integration Fact Sheet

Energy Technology Data Exchange (ETDEWEB)

None

2016-06-01

This fact sheet is an overview of the Systems Integration subprogram at the U.S. Department of Energy SunShot Initiative. The Systems Integration subprogram enables the widespread deployment of safe, reliable, and cost-effective solar energy technologies by addressing the associated technical and non-technical challenges. These include timely and cost-effective interconnection procedures, optimal system planning, accurate prediction of solar resources, monitoring and control of solar power, maintaining grid reliability and stability, and many more. To address the challenges associated with interconnecting and integrating hundreds of gigawatts of solar power onto the electricity grid, the Systems Integration program funds research, development, and demonstration projects in four broad, interrelated focus areas: grid performance and reliability, dispatchability, power electronics, and communications.

Elements of a method to scale ignition reactor Tokamak

International Nuclear Information System (INIS)

Cotsaftis, M.

1984-08-01

Due to unavoidable uncertainties from present scaling laws when projected to thermonuclear regime, a method is proposed to minimize these uncertainties in order to figure out the main parameters of ignited tokamak. The method mainly consists in searching, if any, a domain in adapted parameters space which allows Ignition, but is the least sensitive to possible change in scaling laws. In other words, Ignition domain is researched which is the intersection of all possible Ignition domains corresponding to all possible scaling laws produced by all possible transports

Shock Tube Ignition Delay Data Affected by Localized Ignition Phenomena

KAUST Repository

Javed, Tamour; Badra, J.; Jaasim, Mohammed; Es-sebbar, Et-touhami; Labastida, M.F.; Chung, Suk-Ho; Im, Hong G.; Farooq, Aamir

2016-01-01

Shock tubes have conventionally been used for measuring high-temperature ignition delay times ~ O(1 ms). In the last decade or so, the operating regime of shock tubes has been extended to lower temperatures by accessing longer observation times

Self-organized ignition of a tokamak plasma

International Nuclear Information System (INIS)

Schoepf, K.

2007-01-01

The continuous progress in the attainment of plasma parameters required for establishing nuclear fusion in magnetically confined plasmas as well as the prospect of feasible steady-state operation has instigated the interest in the physics of burning plasmas [1]. Aside from the required plasma current drive, fusion energy production with tokamaks demands particular attention to confinement and fuelling regimes in order to maintain the plasma density n and temperature T at favourable values matching with specific requirements such as the triple product nτ E T, where τ E represents the plasma energy confinement time. The identification of state and parameter space regions capable of ignited fusion plasma operation is evidently crucial if significant energy gains are to be realized over longer periods. Examining the time-evolving state of tokamak fusion plasma in a parameter space spanned by the densities of plasma constituents and their temperatures has led to the formation of an ignition criterion [2] fundamentally different from the commonly used static patterns. The incorporation of non-stationary particle and energy balances into the analysis here, the application of a 'soft' Troyon beta limit [3], the consideration of actual fusion power deposition [4,5] and its effect of reducing τ E are seen to significantly influence the fusion burn dynamics and to shape the ignition conditions. The presented investigation refers to a somewhat upgraded (to achieve ignition) ITER-like tokamak plasma and uses volume averages of locally varying quantities and processes. The resulting ignition criterion accounts for the dynamic evolution of a reacting plasma controlled by heating and fuel feeding. Interestingly, also self-organized ignition can be observed: a fusion plasma possessing a density and temperature above a distinct separatrix in the considered parameter phase space is seen to evolve - without external heating and hence practically by itself - towards an ignited

Ignition analysis for burn control and diagnostic developments in ITER

International Nuclear Information System (INIS)

Mitarai, O.; Muraoka, K.

1997-01-01

The temporal evolutions of the operating point during the ignition access and ignited operation phases are analysed on the basis of zero dimensional (0-D) equations in order to clarify the requirements for safe control of ignited operation and for the development of diagnostic systems in ITER. A stable and safe method of reaching the ignited operating point is identified as the 'higher temperature access' method, being compatible with the H mode power threshold constraints. It is found that the ignition boundary can be experimentally determined by a 'thermonuclear oscillation' of the operating point without knowing the power balance equation. On the other hand, the ignition boundary determined by the power balance equation has a larger error bar depending on the accuracy of the diagnostic system. The plasma waveform response to sudden changes in the various plasma parameters during ignited operation is also calculated, and fusion power regulation is demonstrated by feedback control of the fuelling and auxiliary heating power. (author)

High-speed VCSEL-based optical interconnects

Science.gov (United States)

Ishak, Waguih S.

2001-11-01

Vertical Cavity Surface Emitting Lasers (VCSEL) have made significant inroads into commercial realization especially in the area of data communications. Single VCSEL devices are key components in Gb Ethernet Transceivers. A multi-element VCSEL array is the key enabling technology for high-speed multi Gb/s parallel optical interconnect modules. In 1996, several companies introduced a new generation of fiber optic products based VCSEL technology such as multimode fiber transceivers for the ANSI Fiber Channel and Gigabit Ethernet IEEE 802.3 standards. VCSELs offer unique advantages over its edge-emitting counterparts in several areas. These include low-cost (LED-like) manufacturability, low current operation and array integrability. As data rates continue to increase, VCSELs offer the advantage of being able to provide the highest modulation bandwidth per milliamp of modulation current. Currently, most of the VCSEL-based products use short (780 - 980 nm) wavelength lasers. However, significant research efforts are taking place at universities and industrial research labs around the world to develop reliable, manufacturable and high-power long (1300 - 1550 nm) wavelength VCSELs. These lasers will allow longer (several km) transmission distances and will help alleviate some of the eye-safety issues. Perhaps, the most important advantage of VCSELs is the ability to form two-dimensional arrays much easier than in the case of edge-emitting lasers. These arrays (single and two-dimensional) will allow a whole new family of applications, specifically in very high-speed computer and switch interconnects.

Optical interconnects based on VCSELs and low-loss silicon photonics

Science.gov (United States)

Aalto, Timo; Harjanne, Mikko; Karppinen, Mikko; Cherchi, Matteo; Sitomaniemi, Aila; Ollila, Jyrki; Malacarne, Antonio; Neumeyr, Christian

2018-02-01

Silicon photonics with micron-scale Si waveguides offers most of the benefits of submicron SOI technology while avoiding most of its limitations. In particular, thick silicon-on-insulator (SOI) waveguides offer 0.1 dB/cm propagation loss, polarization independency, broadband single-mode (SM) operation from 1.2 to >4 µm wavelength and ability to transmit high optical powers (>1 W). Here we describe the feasibility of Thick-SOI technology for advanced optical interconnects. With 12 μm SOI waveguides we demonstrate efficient coupling between standard single-mode fibers, vertical-cavity surface-emitting lasers (VCSELs) and photodetectors (PDs), as well as wavelength multiplexing in small footprint. Discrete VCSELs and PDs already support 28 Gb/s on-off keying (OOK), which shows a path towards 50-100 Gb/s bandwidth per wavelength by using more advanced modulation formats like PAM4. Directly modulated VCSELs enable very power-efficient optical interconnects for up to 40 km distance. Furthermore, with 3 μm SOI waveguides we demonstrate extremely dense and low-loss integration of numerous optical functions, such as multiplexers, filters, switches and delay lines. Also polarization independent and athermal operation is demonstrated. The latter is achieved by using short polymer waveguides to compensate for the thermo-optic effect in silicon. New concepts for isolator integration and polarization rotation are also explained.

Shock ignition of thermonuclear fuel: principles and modelling

International Nuclear Information System (INIS)

Atzeni, S.; Ribeyre, X.; Schurtz, G.; Schmitt, A.J.; Canaud, B.; Betti, R.; Perkins, L.J.

2014-01-01

Shock ignition is an approach to direct-drive inertial confinement fusion (ICF) in which the stages of compression and hot spot formation are partly separated. The fuel is first imploded at a lower velocity than in conventional ICF. Close to stagnation, an intense laser spike drives a strong converging shock, which contributes to hot spot formation. Shock ignition shows potentials for high gain at laser energies below 1 MJ, and could be tested on the National Ignition Facility or Laser MegaJoule. Shock ignition principles and modelling are reviewed in this paper. Target designs and computer-generated gain curves are presented and discussed. Limitations of present studies and research needs are outlined. (special topic)

Identifying influential spreaders in interconnected networks

International Nuclear Information System (INIS)

Zhao, Dawei; Li, Lixiang; Huo, Yujia; Yang, Yixian; Li, Shudong

2014-01-01

Identifying the most influential spreaders in spreading dynamics is of the utmost importance for various purposes for understanding or controlling these processes. The existing relevant works are limited to a single network. Most real networks are actually not isolated, but typically coupled and affected by others. The properties of epidemic spreading have recently been found to have some significant differences in interconnected networks from those in a single network. In this paper, we focus on identifying the influential spreaders in interconnected networks. We find that the well-known k-shell index loses effectiveness; some insignificant spreaders in a single network become the influential spreaders in the whole interconnected networks while some influential spreaders become no longer important. The simulation results show that the spreading capabilities of the nodes not only depend on their influence for the network topology, but also are dramatically influenced by the spreading rate. Based on this perception, a novel index is proposed for measuring the influential spreaders in interconnected networks. We then support the efficiency of this index with numerical simulations. (paper)

In memory of Alois Apfelbeck: An Interconnection between Cayley-Eisenstein-Pólya and Landau Probability Distributions

Directory of Open Access Journals (Sweden)

Vladimír Vojta

2013-01-01

Full Text Available The interconnection between the Cayley-Eisenstein-Pólya distribution and the Landau distribution is studied, and possibly new transform pairs for the Laplace and Mellin transform and integral expressions for the Lambert W function have been found.

Study of the shock ignition scheme in inertial confinement fusion

International Nuclear Information System (INIS)

Lafon, M.

2011-01-01

The Shock Ignition (SI) scheme is an alternative to classical ignition schemes in Inertial Confinement Fusion. Its singularity relies on the relaxation of constraints during the compression phase and fulfilment of ignition conditions by launching a short and intense laser pulse (∼500 ps, ∼300 TW) on the pre-assembled fuel at the end of the implosion.In this thesis, it has been established that the SI process leads to a non-isobaric fuel configuration at the ignition time thus modifying the ignition criteria of Deuterium-Tritium (DT) against the conventional schemes. A gain model has been developed and gain curves have been inferred and numerically validated. This hydrodynamical modeling has demonstrated that the SI process allows higher gain and lower ignition energy threshold than conventional ignition due to the high hot spot pressure at ignition time resulting from the ignitor shock propagation.The radiative hydrodynamic CHIC code developed at the CELIA laboratory has been used to determine parametric dependences describing the optimal conditions for target design leading to ignition. These numerical studies have enlightened the potential of SI with regards to saving up laser energy, obtain high gains but also to safety margins and ignition robustness.Finally, the results of the first SI experiments performed in spherical geometry on the OMEGA laser facility (NY, USA) are presented. An interpretation of the experimental data is proposed from mono and bidimensional hydrodynamic simulations. Then, different trails are explored to account for the differences observed between experimental and numerical data and alternative solutions to improve performances are suggested. (author) [fr

The National Ignition Facility

International Nuclear Information System (INIS)

Hogan, W.J.; Moses, E.; Warner, B.; Sorem, M.; Soures, J.M.

2001-01-01

The National Ignition Facility (NIF) is the largest construction project ever undertaken at Lawrence Livermore National Laboratory (LLNL). NIF consists of 192 forty-centimeter-square laser beams and a 10-m-diameter target chamber. NIF is being designed and built by an LLNL-led team from Los Alamos National Laboratory, Sandia National Laboratories, the University of Rochester, and LLNL. Physical construction began in 1997. The Laser and Target Area Building and the Optics Assembly Building were the first major construction activities, and despite several unforeseen obstacles, the buildings are now 92% complete and have been done on time and within cost. Prototype component development and testing has proceeded in parallel. Optics vendors have installed full-scale production lines and have done prototype production runs. The assembly and integration of the beampath infrastructure has been reconsidered and a new approach has been developed. This paper will discuss the status of the NIF project and the plans for completion. (author)

Regulatory Issues Surrounding Merchant Interconnection

International Nuclear Information System (INIS)

Kuijlaars, Kees-Jan; Zwart, Gijsbert

2003-11-01

We discussed various issues concerning the regulatory perspective on private investment in interconnectors. One might claim that leaving investment in transmission infrastructure to competing market parties is more efficient than relying on regulated investment only (especially in the case of long (DC) lines connecting previously unconnected parts of the grids, so that externalities from e.g. loop flows do not play a significant role). We considered that some aspects of interconnection might reduce these market benefits. In particular, the large fixed costs of interconnection construction may lead to significant under investment (due to both first mover monopoly power and the fact that part of generation cost efficiencies realised by interconnection are not captured by the investor itself, and remain external to the investment decision). Second, merchant ownership restricts future opportunities for adaptation of regulation, as would be required e.g. for introduction of potentially more sophisticated methods of congestion management or market splitting. Some of the disadvantages of merchant investment may be mitigated however by a suitable regulatory framework, and we discussed some views in this direction. The issues we discussed are not intended to give a complete framework, and detailed regulation will certainly involve many more specific requirements. Areas we did not touch upon include e.g. the treatment of deep connection costs, rules for operation and maintenance of the line, and impact on availability of capacity on other interconnections

Regulatory Issues Surrounding Merchant Interconnection

Energy Technology Data Exchange (ETDEWEB)

Kuijlaars, Kees-Jan; Zwart, Gijsbert [Office for Energy Regulation (DTe), The Hague (Netherlands)

2003-11-01

We discussed various issues concerning the regulatory perspective on private investment in interconnectors. One might claim that leaving investment in transmission infrastructure to competing market parties is more efficient than relying on regulated investment only (especially in the case of long (DC) lines connecting previously unconnected parts of the grids, so that externalities from e.g. loop flows do not play a significant role). We considered that some aspects of interconnection might reduce these market benefits. In particular, the large fixed costs of interconnection construction may lead to significant under investment (due to both first mover monopoly power and the fact that part of generation cost efficiencies realised by interconnection are not captured by the investor itself, and remain external to the investment decision). Second, merchant ownership restricts future opportunities for adaptation of regulation, as would be required e.g. for introduction of potentially more sophisticated methods of congestion management or market splitting. Some of the disadvantages of merchant investment may be mitigated however by a suitable regulatory framework, and we discussed some views in this direction. The issues we discussed are not intended to give a complete framework, and detailed regulation will certainly involve many more specific requirements. Areas we did not touch upon include e.g. the treatment of deep connection costs, rules for operation and maintenance of the line, and impact on availability of capacity on other interconnections.

Transport simulations of ohmic ignition experiment: IGNITEX

International Nuclear Information System (INIS)

Uckan, N.A.; Howe, H.C.

1987-01-01

The IGNITEX device, proposed by Rosenbluth et al., is a compact, super-high-field, high-current, copper-coil tokamak envisioned to reach ignition with ohmic (OH) heating alone. Several simulations of IGNITEX were made with a 0-D global model and with the 1-D PROCTR transport code. It is shown that OH ignition is a sensitive function of the assumptions about density profile, wall reflectivity of synchrotron radiation, impurity radiation, plasma edge conditions, and additional anomalous losses. In IGNITEX, OH ignition is accessible with nearly all scalings based on favorable OH confinement (such as neo-Alcator). Also, OH ignition appears to be accessible for most (not all) L-mode scalings (such as Kaye-Goldston), provided that the density profile is not too broad (parabolic or more peaked profiles are needed), Z/sub eff/ is not too large (≤2), and anomalous radiation and alpha losses and/or other enhanced transport losses (/eta//sub i/ modes, edge convective energy losses, etc.) are not present. In IGNITEX, because the figure-of-merit parameters (aB 0 2 /q* /approximately/ IB 0 , etc.) are large, ignition can be accessed (either with OH heating alone or with the aid of a small amount of auxiliary power) at relatively low beta, far from stability limits. Once the plasma is ignited, thermal runaway is prevented naturally by a combination of increased synchrotron radiation, burnout of the fuel in the plasma core and replacement by thermal alphas, and the reduction in the thermal plasma confinement assumed in L-mode-like scalings. 12 refs., 5 figs., 1 tab

Transport simulations of ohmic ignition experiment: IGNITEX

International Nuclear Information System (INIS)

Uckan, N.A.; Howe, H.C.

1987-12-01

The IGNITEX device, proposed by Rosenbluth et al., is a compact, super-high-field, high-current, copper-coil tokamak envisioned to reach ignition with ohmic (OH) heating alone. Several simulations of IGNITEX were made with a 0-D global model and with the 1-D PROCTR transport code. It is shown that OH ignition is a sensitive function of the assumptions about density profile, wall reflectivity of synchrotron radiation, impurity radiation, plasma edge conditions, and additional anomalous losses. In IGNITEX, OH ignition is accessible with nearly all scalings based on favorable OH confinement (such as neo-Alcator). Also, OH ignition appears to be accessible for most (not all) L-mode scalings (such as Kaye-Goldston), provided that the density profile is not too broad (parabolic or more peaked profiles are needed), Z/sub eff/ is not too large, and anomalous radiation and alpha losses and/or other enhanced transport losses (eta/sub i/ modes, edge convective energy losses, etc.) are not present. In IGNITEX, because the figure-of-merit parameters are large, ignition can be accessed (either with OH heating alone or with the aid of a small amount of auxiliary power) at relatively low beta, far from stability limits. Once the plasma is ignited, thermal runaway is prevented naturally by a combination of increased synchrotron radiation, burnout of the fuel in the plasma core and replacement by thermal alphas, and the reduction in the thermal plasma confinement assumed in L-mode-like scalings. 12 refs., 5 figs., 1 tab

Present status of Fast Ignition Realization EXperiment (FIREX) and inertial fusion energy development

International Nuclear Information System (INIS)

Azechi, H.; Fujimoto, Y.; Fujioka, S.

2012-11-01

Controlled thermonuclear ignition and subsequent burn will be demonstrated in a couple of years on the central ignition scheme. Fast ignition has the high potential to ignite a fuel using only about one tenth of laser energy necessary to the central ignition. This compactness may largely accelerate inertial fusion energy development. One of the most advanced fast ignition programs is the Fast Ignition Realization Experiment (FIREX). The goal of its first phase is to demonstrate ignition temperature of 5 keV, followed by the second phase to demonstrate ignition-and-burn. The second series experiment of FIREX-I from late 2010 to early 2011 has demonstrated a high (≈20%) coupling efficiency from laser to thermal energy of the compressed core, suggesting that one can achieve the ignition temperature at the laser energy below 10 kJ. Given the demonstrations of the ignition temperature at FIREX-I and the ignition-and-burn at the National Ignition Facility, the inertial fusion research would then shift from the plasma physics era to power generation era. (author)

Shock ignition of high gain inertial fusion capsules

International Nuclear Information System (INIS)

Schurtz, G.; Ribeyre, X.; Lebel, E.; Casner, A.

2010-01-01

Complete text of publication follows. Inertial Confinement Fusion relies on the compression of small amounts of an equimolar mix of Deuterium and Tritium (DT) up to volumic masses of several hundreds of g/cm 3 . Such high densities are obtained by means of the implosion of a spherical shell made of cryogenic DT fuel. In the conventional scheme a hot spot is formed in the central part of the pellet at the end of the implosion. If the pressure of this hot spot is large enough (several hundreds of Gbars), thermonuclear heating occurs with a characteristic time shorter than the hydrodynamic confinement time and the target self ignites. Since the central hot spot pressure results from the conversion of the shell kinetic energy into thermal energy, the threshold for the ignition of a given mass of DT is a direct function of the implosion velocity. Typical implosion velocities for central self ignition are of the order of 400 km/s. Such high velocities imply both a strong acceleration of the shell and the use of large aspect ration shells in order to optimize the hydrodynamic efficiency of the implosion, at least in direct drive. These two features strongly enhance the risk of shell beak up at time of acceleration under the Rayleigh-Taylor instability. Furthermore the formation of the hot spot may itself the unstable, this reducing its effective mass. High compression may be achieved at much lower velocities, thus reducing the energy budget and enhancing the implosion safety, but the corresponding fuel assembly requires an additional heating in order to reach ignition. This heating may be obtained from a 70-100 kJ laser pulse, delivered in 10-15 ps (Fast Ignition). An alternative idea is to boost up the central pressure of a target imploded at a sub-ignition velocity by means of a convergent strong shock launched at the end of the compression phase. This Shock Ignition (SI) concept has been suggested in 1983 by Scherbakov et al. More recently, R. Betti et al. developed

Ignition in net for different energy confinement time scalings

International Nuclear Information System (INIS)

Johner, J.; Prevot, F.

1988-06-01

A zero-dimensional profile dependent model is used to assess the feasibility of ignition in the extended version of NET. Five recent scalings for the energy confinement time (Goldston, Kaye All, Kaye Big, Shimomura-Odajima, Rebut-Lallia) are compared in the frame of two different scenarii, i.e., H-mode with a flat density profile or L-mode with a peaked density profile. For the flat density H-mode case, ignition is accessible with none of the scalings except Rebut-Lallia's. For the peaked density L-mode case, ignition is accessible with none of the scalings except Rebut-Lallia's. For the two Kaye's scalings, ignition is forbidden in H-mode even with the peaked density profile. For the Rebut-Lallia scaling, ignition is allowed in L-mode even with the flat density profile

Free-Space Optical Interconnect Employing VCSEL Diodes

Science.gov (United States)

Simons, Rainee N.; Savich, Gregory R.; Torres, Heidi

2009-01-01

Sensor signal processing is widely used on aircraft and spacecraft. The scheme employs multiple input/output nodes for data acquisition and CPU (central processing unit) nodes for data processing. To connect 110 nodes and CPU nodes, scalable interconnections such as backplanes are desired because the number of nodes depends on requirements of each mission. An optical backplane consisting of vertical-cavity surface-emitting lasers (VCSELs), VCSEL drivers, photodetectors, and transimpedance amplifiers is the preferred approach since it can handle several hundred megabits per second data throughput.The next generation of satellite-borne systems will require transceivers and processors that can handle several Gb/s of data. Optical interconnects have been praised for both their speed and functionality with hopes that light can relieve the electrical bottleneck predicted for the near future. Optoelectronic interconnects provide a factor of ten improvement over electrical interconnects.

Brookhaven segment interconnect

International Nuclear Information System (INIS)

Morse, W.M.; Benenson, G.; Leipuner, L.B.

1983-01-01

We have performed a high energy physics experiment using a multisegment Brookhaven FASTBUS system. The system was composed of three crate segments and two cable segments. We discuss the segment interconnect module which permits communication between the various segments

An Additively Manufactured Torch Igniter for Liquid Propellants

Data.gov (United States)

National Aeronautics and Space Administration — Consistent and reliable rocket engine ignition has yet to be proven through an additively manufactured torch igniter for liquid propellants. The coupling of additive...

National Ignition Facility (NIF) Control Network Design and Analysis

International Nuclear Information System (INIS)

Bryant, R M; Carey, R W; Claybourn, R V; Pavel, G; Schaefer, W J

2001-01-01

The control network for the National Ignition Facility (NIF) is designed to meet the needs for common object request broker architecture (CORBA) inter-process communication, multicast video transport, device triggering, and general TCP/IP communication within the NIF facility. The network will interconnect approximately 650 systems, including the embedded controllers, front-end processors (FEPs), supervisory systems, and centralized servers involved in operation of the NIF. All systems are networked with Ethernet to serve the majority of communication needs, and asynchronous transfer mode (ATM) is used to transport multicast video and synchronization triggers. CORBA software infra-structure provides location-independent communication services over TCP/IP between the application processes in the 15 supervisory and 300 FEP systems. Video images sampled from 500 video cameras at a 10-Hz frame rate will be multicast using direct ATM Application Programming Interface (API) communication from video FEPs to any selected operator console. The Ethernet and ATM control networks are used to broadcast two types of device triggers for last-second functions in a large number of FEPs, thus eliminating the need for a separate infrastructure for these functions. Analysis, design, modeling, and testing of the NIF network has been performed to provide confidence that the network design will meet NIF control requirements

Ignited tokamak devices with ohmic-heating dominated startup

International Nuclear Information System (INIS)

Cohn, D.R.; Bromberg, L.; Jassby, D.L.

1986-01-01

Startup of tokamaks such that the auxiliary heating power is significantly less than the ohmic heating power at all times during heating to ignition can be referred to as ''Ohmic-heating dominated startup.'' Operation in this mode could increase the certainty of heating to ignition since energy confinement during startup may be described by present scaling laws for ohmic heating. It could also reduce substantially the auxiliary heating power (the required power may be quite large for auxiliary-heating dominated startup). These advantages might be realized without the potentially demanding requirements for pure ohmic heating to ignition. In this paper the authors discuss the requirements for ohmic-heating dominated startup and present illustrative design parameters for compact experiment ignition devices that use high performance copper magnets

Signal Integrity Analysis of High-Speed Interconnects

CERN Document Server

Oltean Karlsson, A

2007-01-01

LHC detectors and future experiments will produce very large amount of data that will be transferred at multi-Gigabit speeds. At such data rates, signal-integrity effects become important and traditional rules of thumb are no longer enough for the design and layout of the traces. Simulations for signal-integrity effects at board level provide a way to study and validate several scenarios before arriving at a set of optimized design rules prior to building the actual printed circuit board (PCB). This article describes some of the available tools at CERN. Two case studies will be used to highlight the capabilities of these programs.

Contactless Electric Igniter for Vehicle to Lower Exhaust Emission and Fuel Consumption

Directory of Open Access Journals (Sweden)

Chih-Lung Shen

2014-01-01

Full Text Available An electric igniter for engine/hybrid vehicles is presented. The igniter comprises a flyback converter, a voltage-stacked capacitor, a PIC-based controller, a differential voltage detector, and an ignition coil, of which structure is non-contact type. Since the electric igniter adopts a capacitor to accumulate energy for engine ignition instead of traditional contacttype approach, it enhances the igniting performance of a spark plug effectively. As a result, combustion efficiency is promoted, fuel consumption is saved, and exhaust emission is reduced. The igniter not only is good for fuel efficiency but also can reduce HC and CO emission significantly, which therefore is an environmentally friendly product. The control core of the igniter is implemented on a single chip, which lowers discrete component count, reduces system volume, and increases reliability. In addition, the ignition timing can be programmed so that a timing regulator can be removed from the proposed system, simplifying its structure. To verify the feasibility and functionality of the igniter, key waveforms are measured and real-car experiments are performed as well.

Ignition tuning for the National Ignition Campaign

OpenAIRE

Landen O.; Edwards J.; Haan S.W.; Lindl J.D.; Boehly T.R.; Bradley D.K.; Callahan D.A.; Celliers P.M.; Dewald E.L.; Dixit S.; Doeppner T.; Eggert J.; Farley D.; Frenje J.A.; Glenn S.

2013-01-01

The overall goal of the indirect-drive inertial confinement fusion [1] tuning campaigns [2] is to maximize the probability of ignition by experimentally correcting for likely residual uncertainties in the implosion and hohlraum physics [3] used in our radiation-hydrodynamic computational models, and by checking for and resolving unexpected shot-to-shot variability in performance [4]. This has been started successfully using a variety of surrogate capsules that set key laser, hohlraum and caps...

Towards a modeling synthesis of two or three-dimensional circuits through substrate coupling and interconnections

CERN Document Server

Gontrand, Christian

2014-01-01

The number of transistors in integrated circuits doubles every two years, as stipulated by Moore's law, and this has been the driving force for the huge development of the microelectronics industry in the past 50 years - currently advanced to the nanometric scale.This e-book is dedicated to electronic noises and parasites, accounting for issues involving substrate coupling and interconnections, in the perspective of the 3D integration: a second track for enhancing integration, also compatible with Moore's law. This reference explains the modeling of 3D circuits without delving into the latest

Ignition properties of nuclear grade activated carbons

International Nuclear Information System (INIS)

Freeman, W.P.; Hunt, J.R.; Kovach, J.L.

1983-01-01

The ignition property of new activated carbons used in air cleaning systems of nuclear facilities has been evaluated in the past, however very little information has been generated on the behavior of aged, weathered carbons which have been exposed to normal nuclear facility environment. Additionally the standard procedure for evaluation of ignition temperature of carbon is performed under very different conditions than those used in the design of nuclear air cleaning systems. Data were generated evaluating the ageing of activated carbons and comparing their CH 3 131 I removal histories to their ignition temperatures. A series of tests were performed on samples from one nuclear power reactor versus use time, a second series evaluated samples from several plants showing the variability of atmospheric effects. The ignition temperatures were evaluated simulating the conditions existing in nuclear air cleaning systems, such as velocity, bed depth, etc., to eliminate potential confusion resulting from artifically set current standard conditions

Physics evaluation of compact tokamak ignition experiments

International Nuclear Information System (INIS)

Uckan, N.A.; Houlberg, W.A.; Sheffield, J.

1985-01-01

At present, several approaches for compact, high-field tokamak ignition experiments are being considered. A comprehensive method for analyzing the potential physics operating regimes and plasma performance characteristics of such ignition experiments with O-D (analytic) and 1-1/2-D (WHIST) transport models is presented. The results from both calculations are in agreement and show that there are regimes in parameter space in which a class of small (R/sub o/ approx. 1-2 m), high-field (B/sub o/ approx. 8-13 T) tokamaks with aB/sub o/ 2 /q/sub */ approx. 25 +- 5 and kappa = b/a approx. 1.6-2.0 appears ignitable for a reasonable range of transport assumptions. Considering both the density and beta limits, an evaluation of the performance is presented for various forms of chi/sub e/ and chi/sub i/, including degradation at high power and sawtooth activity. The prospects of ohmic ignition are also examined. 16 refs., 13 figs

76 FR 45248 - PJM Interconnection, L.L.C., PJM Power Providers Group v. PJM Interconnection, L.L.C...

Science.gov (United States)

2011-07-28

...-002; Docket No. EL11-20-001] PJM Interconnection, L.L.C., PJM Power Providers Group v. PJM Interconnection, L.L.C.; Supplemental Notice of Staff Technical Conference On June 13, 2011, the Commission issued... Resources Services, Inc., Maryland Public Service Commission, Monitoring Analytics, L.L.C., National Rural...

Confinement scaling and ignition in tokamaks

International Nuclear Information System (INIS)

Perkins, F.W.; Sun, Y.C.

1985-10-01

A drift wave turbulence model is used to compute the scaling and magnitude of central electron temperature and confinement time of tokamak plasmas. The results are in accord with experiment. Application to ignition experiments shows that high density (1 to 2) . 10 15 cm -3 , high field, B/sub T/ > 10 T, but low temperature T approx. 6 keV constitute the optimum path to ignition

Fast ignition: Dependence of the ignition energy on source and target parameters for particle-in-cell-modelled energy and angular distributions of the fast electrons

Energy Technology Data Exchange (ETDEWEB)

Bellei, C.; Divol, L.; Kemp, A. J.; Key, M. H.; Larson, D. J.; Strozzi, D. J.; Marinak, M. M.; Tabak, M.; Patel, P. K. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)

2013-05-15

The energy and angular distributions of the fast electrons predicted by particle-in-cell (PIC) simulations differ from those historically assumed in ignition designs of the fast ignition scheme. Using a particular 3D PIC calculation, we show how the ignition energy varies as a function of source-fuel distance, source size, and density of the pre-compressed fuel. The large divergence of the electron beam implies that the ignition energy scales with density more weakly than the ρ{sup −2} scaling for an idealized beam [S. Atzeni, Phys. Plasmas 6, 3316 (1999)], for any realistic source that is at some distance from the dense deuterium-tritium fuel. Due to the strong dependence of ignition energy with source-fuel distance, the use of magnetic or electric fields seems essential for the purpose of decreasing the ignition energy.

SSC [Superconducting Super Collider] magnet mechanical interconnections

International Nuclear Information System (INIS)

Bossert, R.C.; Niemann, R.C.; Carson, J.A.; Ramstein, W.L.; Reynolds, M.P.; Engler, N.H.

1989-03-01

Installation of superconducting accelerator dipole and quadrupole magnets and spool pieces in the SSC tunnel requires the interconnection of the cryostats. The connections are both of an electrical and mechanical nature. The details of the mechanical connections are presented. The connections include piping, thermal shields and insulation. There are seven piping systems to be connected. These systems must carry cryogenic fluids at various pressures or maintain vacuum and must be consistently leak tight. The interconnection region must be able to expand and contract as magnets change in length while cooling and warming. The heat leak characteristics of the interconnection region must be comparable to that of the body of the magnet. Rapid assembly and disassembly is required. The magnet cryostat development program is discussed. Results of quality control testing are reported. Results of making full scale interconnections under magnet test situations are reviewed. 11 figs., 4 tabs

Progress on LMJ targets for ignition

International Nuclear Information System (INIS)

Cherfils-Clerouin, C; Boniface, C; Bonnefille, M; Fremerye, P; Galmiche, D; Gauthier, P; Giorla, J; Lambert, F; Laffite, S; Liberatore, S; Loiseau, P; Malinie, G; Masse, L; Masson-Laborde, P E; Monteil, M C; Poggi, F; Seytor, P; Wagon, F; Willien, J L

2010-01-01

Targets designed to produce ignition on the Laser MegaJoule are presented. The LMJ experimental plans include the attempt of ignition and burn of an ICF capsule with 160 laser beams, delivering up to 1.4MJ and 380TW. New targets needing reduced laser energy with only a small decrease in robustness have then been designed for this purpose. Working specifically on the coupling efficiency parameter, i.e. the ratio of the energy absorbed by the capsule to the laser energy, has led to the design of a rugby-shaped cocktail hohlraum. 1D and 2D robustness evaluations of these different targets shed light on critical points for ignition, that can be traded off by tightening some specifications or by preliminary experimental and numerical tuning experiments.

Progress on LMJ targets for ignition

Energy Technology Data Exchange (ETDEWEB)

Cherfils-Clerouin, C; Boniface, C; Bonnefille, M; Fremerye, P; Galmiche, D; Gauthier, P; Giorla, J; Lambert, F; Laffite, S; Liberatore, S; Loiseau, P; Malinie, G; Masse, L; Masson-Laborde, P E; Monteil, M C; Poggi, F; Seytor, P; Wagon, F; Willien, J L, E-mail: catherine.cherfils@cea.f [CEA, DAM, DIF, F-91297 Arpajon (France)

2010-08-01

Targets designed to produce ignition on the Laser MegaJoule are presented. The LMJ experimental plans include the attempt of ignition and burn of an ICF capsule with 160 laser beams, delivering up to 1.4MJ and 380TW. New targets needing reduced laser energy with only a small decrease in robustness have then been designed for this purpose. Working specifically on the coupling efficiency parameter, i.e. the ratio of the energy absorbed by the capsule to the laser energy, has led to the design of a rugby-shaped cocktail hohlraum. 1D and 2D robustness evaluations of these different targets shed light on critical points for ignition, that can be traded off by tightening some specifications or by preliminary experimental and numerical tuning experiments.

Fusion-bonded fluidic interconnects

International Nuclear Information System (INIS)

Fazal, I; Elwenspoek, M C

2008-01-01

A new approach to realize fluidic interconnects based on the fusion bonding of glass tubes with silicon is presented. Fusion bond strength analyses have been carried out. Experiments with plain silicon wafers and coated with silicon oxide and silicon nitride are performed. The obtained results are discussed in terms of the homogeneity and strength of fusion bond. High pressure testing shows that the bond strength is large enough for most applications of fluidic interconnects. The bond strength for 525 µm thick silicon, with glass tubes having an outer diameter of 6 mm and with a wall thickness of 2 mm, is more than 60 bars after annealing at a temperature of 800 °C

Ignition delays, heats of combustion, and reaction rates of aluminum alkyl derivatives used as ignition and combustion enhancers for supersonic combustion

Science.gov (United States)

Ryan, Thomas W., III; Schwab, S. T.; Harlowe, W. W.

1992-01-01

The subject of this paper is the design of supersonic combustors which will be required in order to achieve the needed reaction rates in a reasonable sized combustor. A fuel additive approach, which is the focus of this research, is the use of pyrophorics to shorten the ignition delay time and to increase the energy density of the fuel. Pyrophoric organometallic compounds may also provide an ignition source and flame stabilization mechanism within the combustor, thus permitting use of hydrocarbon fuels in supersonic combustion systems. Triethylaluminum (TEA) and trimethylaluminum (TMA) were suggested for this application due to their high energy density and reactivity. The objective here is to provide comparative data for the ignition quality, the energy content, and the reaction rates of several different adducts of both TEA and TMA. The results of the experiments indicate the aluminum alkyls and their more stable derivatives reduce the ignition delay and total reaction time to JP-10 jet fuel. Furthermore, the temperature dependence of ignition delay and total reaction time of the blends of the adducts are significantly lower than in neat JP-10.

Chemical kinetic insights into the ignition dynamics of n-hexane

KAUST Repository

Tingas, Alexandros

2017-10-13

Normal alkanes constitute a significant fraction of transportation fuels, and are the primary drivers of ignition processes in gasoline and diesel fuels. Low temperature ignition of n-alkanes is driven by a complex sequence of oxidation reactions, for which detailed mechanisms are still being developed. The current study explores the dynamics of low-temperature ignition of n-hexane/air mixtures, and identifies chemical pathways that characterize the combustion process. Two chemical kinetic mechanisms were selected as a comparative study in order to better understand the role of specific reaction sequences in ignition dynamics: one mechanism including a new third sequential O2 addition reaction pathways (recently proposed by Wang et al. 2017), while the other without (Zhang et al. 2015). The analysis is conducted by applying tools generated from the computational singular perturbation (CSP) approach to two distinct ignition phenomena: constant volume and compression ignition. In both cases, the role of the third sequential O2 addition reactions proves to be significant, although it is found to be much more pronounced in the constant volume cases compared to the HCCI. In particular, in the constant volume ignition case, reactions present in the third sequential O2 addition reaction pathways (e.g., KDHP  →  products + OH) contribute significantly to the explosivity of the mixture; when accounted for along with reactions P(OOH)2 + O2  →  OOP(OOH)2 and OOP(OOH)2  →  KDHP + OH, they decrease ignition delay time of the mixture by up to 40%. Under HCCI conditions, in the first-stage ignition, the third-O2 addition reactions contribute to the process, although their role decays with time and becomes negligible at the end of the first stage. The second ignition stage is dominated almost exclusively by hydrogen-related chemistry.

Colligation, Or the Logical Inference of Interconnection

DEFF Research Database (Denmark)

Falster, Peter

1998-01-01

laws or assumptions. Yet interconnection as an abstract concept seems to be without scientific underpinning in pure logic. Adopting a historical viewpoint, our aim is to show that the reasoning of interconnection may be identified with a neglected kind of logical inference, called "colligation...

Colligation or, The Logical Inference of Interconnection

DEFF Research Database (Denmark)

Franksen, Ole Immanuel; Falster, Peter

2000-01-01

laws or assumptions. Yet interconnection as an abstract concept seems to be without scientific underpinning in oure logic. Adopting a historical viewpoint, our aim is to show that the reasoning of interconnection may be identified with a neglected kind of logical inference, called "colligation...

Structured approaches to large-scale systems: Variational integrators for interconnected Lagrange-Dirac systems and structured model reduction on Lie groups

Science.gov (United States)

Parks, Helen Frances

This dissertation presents two projects related to the structured integration of large-scale mechanical systems. Structured integration uses the considerable differential geometric structure inherent in mechanical motion to inform the design of numerical integration schemes. This process improves the qualitative properties of simulations and becomes especially valuable as a measure of accuracy over long time simulations in which traditional Gronwall accuracy estimates lose their meaning. Often, structured integration schemes replicate continuous symmetries and their associated conservation laws at the discrete level. Such is the case for variational integrators, which discretely replicate the process of deriving equations of motion from variational principles. This results in the conservation of momenta associated to symmetries in the discrete system and conservation of a symplectic form when applicable. In the case of Lagrange-Dirac systems, variational integrators preserve a discrete analogue of the Dirac structure preserved in the continuous flow. In the first project of this thesis, we extend Dirac variational integrators to accommodate interconnected systems. We hope this work will find use in the fields of control, where a controlled system can be thought of as a "plant" system joined to its controller, and in the approach of very large systems, where modular modeling may prove easier than monolithically modeling the entire system. The second project of the thesis considers a different approach to large systems. Given a detailed model of the full system, can we reduce it to a more computationally efficient model without losing essential geometric structures in the system? Asked without the reference to structure, this is the essential question of the field of model reduction. The answer there has been a resounding yes, with Principal Orthogonal Decomposition (POD) with snapshots rising as one of the most successful methods. Our project builds on previous work

Barriers and drivers of new interconnections between EU and non-EU electricity systems. Economic and regulatory aspects

International Nuclear Information System (INIS)

Van Werven, M.J.N.; Van Oostvoorn, F.

2006-05-01

interconnectors, market structure, and security of supply measures. In conclusion, interconnection with neighbouring regions can definitively offer several advantages and benefits on a European (region) level, but they should be well compared with the integral costs and barriers that arise with it

Time-dependent simulations of a Compact Ignition Tokamak

International Nuclear Information System (INIS)

Stotler, D.P.; Bateman, G.

1988-05-01

Detailed simulations of the Compact Ignition Tokamak are carried out using a 1-1/2-D transport code. The calculations include time-varying densities, fields, and plasma shape. It is shown that ignition can be achieved in this device if somewhat better than L-mode energy confinement time scaling is possible. We also conclude that the performance of such a compact, short-pulse device can depend greatly on how the plasma is evolved to its flat-top parameters. Furthermore, in cases such as the ones discussed here, where there is not a great deal of ignition margin and the electron density is held constant, ignition ends if the helium ash is not removed. In general, control of the deuterium--tritium density is equivalent to burn control. 48 refs., 15 figs

Progress towards ignition on the National Ignition Facility

Energy Technology Data Exchange (ETDEWEB)

Edwards, M. J.; Patel, P. K.; Lindl, J. D.; Atherton, L. J.; Glenzer, S. H.; Haan, S. W.; Landen, O. L.; Moses, E. I.; Springer, P. T.; Benedetti, R.; Bernstein, L.; Bleuel, D. L.; Bradley, D. K.; Caggiano, J. A.; Callahan, D. A.; Celliers, P. M.; Cerjan, C. J.; Clark, D. S.; Collins, G. W.; Dewald, E. L. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States); and others

2013-07-15

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory includes a precision laser system now capable of delivering 1.8 MJ at 500 TW of 0.35-μm light to a target. NIF has been operational since March 2009. A variety of experiments have been completed in support of NIF's mission areas: national security, fundamental science, and inertial fusion energy. NIF capabilities and infrastructure are in place to support its missions with nearly 60 X-ray, optical, and nuclear diagnostic systems. A primary goal of the National Ignition Campaign (NIC) on the NIF was to implode a low-Z capsule filled with ∼0.2 mg of deuterium-tritium (DT) fuel via laser indirect-drive inertial confinement fusion and demonstrate fusion ignition and propagating thermonuclear burn with a net energy gain of ∼5–10 (fusion yield/input laser energy). This requires assembling the DT fuel into a dense shell of ∼1000 g/cm{sup 3} with an areal density (ρR) of ∼1.5 g/cm{sup 2}, surrounding a lower density hot spot with a temperature of ∼10 keV and a ρR ∼0.3 g/cm{sup 2}, or approximately an α-particle range. Achieving these conditions demand precise control of laser and target parameters to allow a low adiabat, high convergence implosion with low ablator fuel mix. We have demonstrated implosion and compressed fuel conditions at ∼80–90% for most point design values independently, but not at the same time. The nuclear yield is a factor of ∼3–10× below the simulated values and a similar factor below the alpha dominated regime. This paper will discuss the experimental trends, the possible causes of the degraded performance (the off-set from the simulations), and the plan to understand and resolve the underlying physics issues.

Modelling piloted ignition of wood and plastics

NARCIS (Netherlands)

Blijderveen, M.; Bramer, Eduard A.; Brem, Gerrit

2012-01-01

To gain insight in the startup of an incinerator, this article deals with piloted ignition. A newly developed model is described to predict the piloted ignition times of wood, PMMA and PVC. The model is based on the lower flammability limit and the adiabatic flame temperature at this limit. The

Dynamic ignition regime of condensed system by radiate heat flux

International Nuclear Information System (INIS)

Arkhipov, V A; Zolotorev, N N; Korotkikh, A G; Kuznetsov, V T

2017-01-01

The main ignition characteristics of high-energy materials are the ignition time and critical heat flux allowing evaluation of the critical conditions for ignition, fire and explosive safety for the test solid propellants. The ignition process is typically studied in stationary conditions of heat input at constant temperature of the heating surface, environment or the radiate heat flux on the sample surface. In real conditions, ignition is usually effected at variable time-dependent values of the heat flux. In this case, the heated layer is formed on the sample surface in dynamic conditions and significantly depends on the heat flux change, i.e. increasing or decreasing falling heat flux in the reaction period of the propellant sample. This paper presents a method for measuring the ignition characteristics of a high-energy material sample in initiation of the dynamic radiant heat flux, which includes the measurement of the ignition time when exposed to a sample time varying radiant heat flux given intensity. In case of pyroxyline containing 1 wt. % of soot, it is shown that the ignition times are reduced by 20–50 % depending on the initial value of the radiant flux density in initiation by increasing or decreasing radiant heat flux compared with the stationary conditions of heat supply in the same ambient conditions. (paper)

Demonstration of Efficient Core Heating of Magnetized Fast Ignition in FIREX project

Science.gov (United States)

Johzaki, Tomoyuki

2017-10-01

Extensive theoretical and experimental research in the FIREX ``I project over the past decade revealed that the large angular divergence of the laser generated electron beam is one of the most critical problems inhibiting efficient core heating in electron-driven fast ignition. To solve this problem, beam guiding using externally applied kilo-tesla class magnetic field was proposed, and its feasibility has recently been numerically demonstrated. In 2016, integrated experiments at ILE Osaka University demonstrated core heating efficiencies reaching > 5 % and heated core temperatures of 1.7 keV. In these experiments, a kilo-tesla class magnetic field was applied to a cone-attached Cu(II) oleate spherical solid target by using a laser-driven capacitor-coil. The target was then imploded by G-XII laser and heated by the PW-class LFEX laser. The heating efficiency was evaluated by measuring the number of Cu-K- α photons emitted. The heated core temperature was estimated by the X-ray intensity ratio of Cu Li-like and He-like emission lines. To understand the detailed dynamics of the core heating process, we carried out integrated simulations using the FI3 code system. Effects of magnetic fields on the implosion and electron beam transport, detailed core heating dynamics, and the resultant heating efficiency and core temperature will be presented. I will also discuss the prospect for an ignition-scale design of magnetized fast ignition using a solid ball target. This work is partially supported by JSPA KAKENHI Grant Number JP16H02245, JP26400532, JP15K21767, JP26400532, JP16K05638 and is performed with the support and the auspices of the NIFS Collaboration Research program (NIFS12KUGK057, NIFS15KUGK087).

Simple and accurate model for voltage-dependent resistance of metallic carbon nanotube interconnects: An ab initio study

International Nuclear Information System (INIS)

Yamacli, Serhan; Avci, Mutlu

2009-01-01

In this work, development of a voltage dependent resistance model for metallic carbon nanotubes is aimed. Firstly, the resistance of metallic carbon nanotube interconnects are obtained from ab initio simulations and then the voltage dependence of the resistance is modeled through regression. Self-consistent non-equilibrium Green's function formalism combined with density functional theory is used for calculating the voltage dependent resistance of metallic carbon nanotubes. It is shown that voltage dependent resistances of carbon nanotubes can be accurately modeled as a polynomial function which enables rapid integration of carbon nanotube interconnect models into electronic design automation tools.

Adapting Memory Hierarchies for Emerging Datacenter Interconnects

Institute of Scientific and Technical Information of China (English)

江涛; 董建波; 侯锐; 柴琳; 张立新; 孙凝晖; 田斌

2015-01-01

Efficient resource utilization requires that emerging datacenter interconnects support both high performance communication and efficient remote resource sharing. These goals require that the network be more tightly coupled with the CPU chips. Designing a new interconnection technology thus requires considering not only the interconnection itself, but also the design of the processors that will rely on it. In this paper, we study memory hierarchy implications for the design of high-speed datacenter interconnects—particularly as they affect remote memory access—and we use PCIe as the vehicle for our investigations. To that end, we build three complementary platforms: a PCIe-interconnected prototype server with which we measure and analyze current bottlenecks; a software simulator that lets us model microarchitectural and cache hierarchy changes;and an FPGA prototype system with a streamlined switchless customized protocol Thunder with which we study hardware optimizations outside the processor. We highlight several architectural modifications to better support remote memory access and communication, and quantify their impact and limitations.

Evaporation and Ignition Characteristics of Water Emulsified Diesel under Conventional and Low Temperature Combustion Conditions

Directory of Open Access Journals (Sweden)

Zhaowen Wang

2017-07-01

Full Text Available The combination of emulsified diesel and low temperature combustion (LTC technology has great potential in reducing engine emissions. A visualization study on the spray and combustion characteristics of water emulsified diesel was conducted experimentally in a constant volume chamber under conventional and LTC conditions. The effects of ambient temperature on the evaporation, ignition and combustion characteristics of water emulsified diesel were studied under cold, evaporating and combustion conditions. Experimental results showed that the ambient temperature had little effect on the spray structures, in terms of the liquid core length, the spray shape and the spray area. However, higher ambient temperature slightly reduced the Sauter Mean Diameter (SMD of the spray droplets. The auto-ignition delay time increased significantly with the decrease of the ambient temperature. The ignition process always occurred at the entrainment region near the front periphery of the liquid core. This entrainment region was evolved from the early injected fuel droplets which were heated and mixed by the continuous entrainment until the local temperature and equivalence ratio reached the ignition condition. The maximum value of integrated natural flame luminosity (INFL reduced by 60% when the ambient temperature dropped from 1000 to 800 K, indicating a significant decrease of the soot emissions could be achieved by LTC combustion mode than the conventional diesel engines.

Effect of laser induced plasma ignition timing and location on Diesel spray combustion

International Nuclear Information System (INIS)

Pastor, José V.; García-Oliver, José M.; García, Antonio; Pinotti, Mattia

2017-01-01

Highlights: • Laser plasma ignition is applied to a direct injection Diesel spray, compared with auto-ignition. • Critical local fuel/air ratio for LIP provoked ignition is obtained. • The LIP system is able to stabilize Diesel combustion compared to auto-ignition cases. • Varying LIP position along spray axis directly affects Ignition-delay. • Premixed combustion is reduced both by varying position and delay of the LIP ignition system. - Abstract: An experimental study about the influence of the local conditions at the ignition location on combustion development of a direct injection spray is carried out in an optical engine. A laser induced plasma ignition system has been used to force the spray ignition, allowing comparison of combustion’s evolution and stability with the case of conventional autoignition on the Diesel fuel in terms of ignition delay, rate of heat release, spray penetration and soot location evolution. The local equivalence ratio variation along the spray axis during the injection process was determined with a 1D spray model, previously calibrated and validated. Upper equivalence ratios limits for the ignition event of a direct injected Diesel spray, both in terms of ignition success possibilities and stability of the phenomena, could been determined thanks to application of the laser plasma ignition system. In all laser plasma induced ignition cases, heat release was found to be higher than for the autoignition reference cases, and it was found to be linked to a decrease of ignition delay, with the premixed peak in the rate of heat release curve progressively disappearing as the ignition delay time gets shorter. Ignition delay has been analyzed as a function of the laser position, too. It was found that ignition delay increases for plasma positions closer to the nozzle, indicating that the amount of energy introduced by the laser induced plasma is not the only parameter affecting combustion initiation, but local equivalence ratio

Role of W and Mn for reliable 1X nanometer-node ultra-large-scale integration Cu interconnects proved by atom probe tomography

Energy Technology Data Exchange (ETDEWEB)

Shima, K.; Shimizu, H.; Momose, T.; Shimogaki, Y. [Department of Materials Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Tu, Y. [The Oarai Center, Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai 200241 (China); Takamizawa, H.; Shimizu, Y.; Inoue, K.; Nagai, Y. [The Oarai Center, Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan)

2014-09-29

We used atom probe tomography (APT) to study the use of a Cu(Mn) as a seed layer of Cu, and a Co(W) single-layer as reliable Cu diffusion barriers for future interconnects in ultra-large-scale integration. The use of Co(W) layer enhances adhesion of Cu to prevent electromigration and stress-induced voiding failures. The use of Cu(Mn) as seed layer may enhance the diffusion barrier performance of Co(W) by stuffing the Cu diffusion pass with Mn. APT was used to visualize the distribution of W and Mn in three dimensions with sub-nanometer resolution. W was found to segregate at the grain boundaries of Co, which prevents diffusion of Cu via the grain boundaries. Mn was found to diffuse from the Cu(Mn) layer to Co(W) layer and selectively segregate at the Co(W) grain boundaries with W, reinforcing the barrier properties of Co(W) layer. Hence, a Co(W) barrier coupled with a Cu(Mn) seed layer can form a sufficient diffusion barrier with film that is less than 2.0-nm-thick. The diffusion barrier behavior was preserved following a 1-h annealing at 400 °C. The underlayer of the Cu interconnects requires a large adhesion strength with the Cu, as well as low electrical resistivity. The use of Co(W) has previously been shown to satisfy these requirements, and addition of Mn is not expected to deteriorate these properties.

National Ignition Facility project acquisition plan revision 1

International Nuclear Information System (INIS)

Clobes, A.R.

1996-01-01

The purpose of this National Ignition Facility Acquisition Plan is to describe the overall procurement strategy planned for the National Ignition Facility M Project. It was prepared for the NIP Prood Office by the NIF Procurement Manager

Approaches to Improve Mixing in Compression Ignition Engines

Energy Technology Data Exchange (ETDEWEB)

Boot, M.D.

2010-04-20

. Therefore, computational fluid dynamics (CFD) calculations of the injection process are performed to confirm whether or not liquid fuel impingement on the combustion chamber walls is indeed reduced as a result of the aforementioned UHC reduction strategies. Combined model and experimental results indicate that, for most strategies, the measured hydrocarbon emissions and predicted spray impingement are well correlated for a conventional DI injector nozzle, supporting the earlier assumption that wall-wetting is responsible for high hydrocarbon emissions in the investigated early injection timing approach. Lastly, in the third approach, a new injector nozzle design is proposed to improve the mixing process; again with the aim of soot abatement. In conventional nozzles, fuel is injected through 5-10 holes with nominal diameters of 100-200 micrometer. From both literature and in-house experiments it is known that mixing can be improved by reducing the nozzle diameter. Unfortunately, in order to preserve the overall flow rate, the number of required holes quadratically increases with a reduction in hole diameter. Alternatively, it is proposed to not drill the holes, but to use a porous medium instead. The utilized medium is a sintered metal permeated by an interconnected network of (continuous) pores with nominal diameters of 10 micrometer. This material is machined into a nozzle like shape and subjected to atmospheric injection tests as well as to experiments in the Eindhoven High Pressure Cell. Macroscopic experimental data (e.g. shorter ignition delay, larger spray volume) suggests that mixing is indeed improved. However, more research is required, preferably in a(n) (optical) engine, to investigate the impact on (soot) emissions and overall engine performance. In addition, the issues of durability and fouling still have to be addressed.

Intermediate species measurement during iso-butanol auto-ignition

KAUST Repository

Ji, Weiqi

2015-10-01

© 2015 The Combustion Institute.Published by Elsevier Inc. All rights reserved. This work presents the time histories of intermediate species during the auto-ignition of iso-butanol at high pressure and intermediate temperature conditions obtained using a rapid compression machine and recently developed fast sampling system. Iso-butanol ignition delays were acquired for iso-butanol/O2 mixture with an inert/O2 ratio of 7.26, equivalence ratio of 0.4, in the temperature range of 840-950 K and at pressure of 25 bar. Fast sampling and gas chromatography were used to acquire and quantify the intermediate species during the ignition delay of the same mixture at P = 25.3 bar and T = 905 K. The ignition delay times and quantitative measurements of the mole fraction time histories of methane, ethene, propene, iso-butene, iso-butyraldehyde, iso-butanol, and carbon monoxide were compared with predictions from the detailed mechanisms developed by Sarathy et al., Merchant et al., and Cai et al. It is shown that while the Sarathy mechanism well predicts the overall ignition delay time, it overpredicts ethene by a factor of 6-10, underpredicts iso-butene by a factor of 2, and overpredicts iso-butyraldehyde by a factor of 2. Reaction path and sensitivity analyses were carried out to identify the reactions responsible for the observed inadequacy. The rates of iso-butanol hydrogen atom abstraction by OH radical and the beta-scission reactions of hydroxybutyl radicals were updated based on recently published quantum calculation results. Significant improvements were achieved in predicting ignition delay at high pressures (25 and 30 bar) and the species concentrations of ethene and iso-butene. However, the updated mechanism still overpredicts iso-butyraldehyde concentrations. Also, the updated mechanism degrades the prediction in ignition delay at lower pressure (15 bar) compared to the original mechanism developed by Sarathy et al.

Intermediate species measurement during iso-butanol auto-ignition

KAUST Repository

Ji, Weiqi; Zhang, Peng; He, Tanjin; Wang, Zhi; Tao, Ling; He, Xin; Law, Chung K.

2015-01-01

© 2015 The Combustion Institute.Published by Elsevier Inc. All rights reserved. This work presents the time histories of intermediate species during the auto-ignition of iso-butanol at high pressure and intermediate temperature conditions obtained using a rapid compression machine and recently developed fast sampling system. Iso-butanol ignition delays were acquired for iso-butanol/O2 mixture with an inert/O2 ratio of 7.26, equivalence ratio of 0.4, in the temperature range of 840-950 K and at pressure of 25 bar. Fast sampling and gas chromatography were used to acquire and quantify the intermediate species during the ignition delay of the same mixture at P = 25.3 bar and T = 905 K. The ignition delay times and quantitative measurements of the mole fraction time histories of methane, ethene, propene, iso-butene, iso-butyraldehyde, iso-butanol, and carbon monoxide were compared with predictions from the detailed mechanisms developed by Sarathy et al., Merchant et al., and Cai et al. It is shown that while the Sarathy mechanism well predicts the overall ignition delay time, it overpredicts ethene by a factor of 6-10, underpredicts iso-butene by a factor of 2, and overpredicts iso-butyraldehyde by a factor of 2. Reaction path and sensitivity analyses were carried out to identify the reactions responsible for the observed inadequacy. The rates of iso-butanol hydrogen atom abstraction by OH radical and the beta-scission reactions of hydroxybutyl radicals were updated based on recently published quantum calculation results. Significant improvements were achieved in predicting ignition delay at high pressures (25 and 30 bar) and the species concentrations of ethene and iso-butene. However, the updated mechanism still overpredicts iso-butyraldehyde concentrations. Also, the updated mechanism degrades the prediction in ignition delay at lower pressure (15 bar) compared to the original mechanism developed by Sarathy et al.

Two-Dimensional Simulations of Electron Shock Ignition at the Megajoule Scale

Science.gov (United States)

Shang, W.; Betti, R.

2016-10-01

Shock ignition uses a late strong shock to ignite the hot spot of an inertial confinement fusion capsule. In the standard shock-ignition scheme, an ignitor shock is launched by the ablation pressure from a spike in laser intensity. Recent experiments on OMEGA have shown that focused beams with intensity up to 6 ×1015 W /cm2 can produce copious amounts of hot electrons. The hot electrons are produced by laser-plasma instabilities (LPI's) and can carry up to 15 % of the instantaneous laser power. Megajoule-scale targets will likely produce even more hot electrons because of the large plasma scale length. We show that it is possible to design ignition targets with low implosion velocities that can be shock ignited using LPI-generated hot electrons to obtain high energy gains. These designs are robust to low-mode asymmetries and they ignite even for highly distorted implosions. Electron shock ignition requires tens of kilojoules of hot electrons, which can only be produced on a large laser facility like the National Ignition Facility. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Ignition condition and gain prediction for perturbed inertial confinement fusion targets

International Nuclear Information System (INIS)

Kishony, Roy; Shvarts, Dov

2001-01-01

The effect of perturbations on hot spot ignition is studied using full two-dimensional (2D) numerical simulations of the National Ignition Facility [J. D. Lindl, Phys. Plasmas 2, 3933 (1995)] direct drive Laboratory for Laser Energetics target design and newly derived 2D self-similar solutions for a perturbed burn wave propagation. It is shown that the required implosion velocity needed for ignition increases with the perturbation mode number and final amplitude, reaching an asymptotic value for high enough perturbation mode numbers, when the entire mixing zone no longer contributes to the ignition of the hot spot. Using the new self-similar solutions, ignition conditions for various perturbation mode numbers and amplitudes are obtained. These ignition conditions, which correspond to areal densities higher than needed for ignition in the symmetric case, are translated to a required increase in the implosion velocity needed for ignition, using the 1D Levendahl-Lindl scaling, in good agreement with the full 2D numerical simulation results. Finally, using the above results, a model for predicting the gain of a perturbed targets as a function of the perturbation spectra (single-mode and multi-mode) is presented, in good agreement with full numerical simulations

Laser printing of 3D metallic interconnects

Science.gov (United States)

Beniam, Iyoel; Mathews, Scott A.; Charipar, Nicholas A.; Auyeung, Raymond C. Y.; Piqué, Alberto

2016-04-01

The use of laser-induced forward transfer (LIFT) techniques for the printing of functional materials has been demonstrated for numerous applications. The printing gives rise to patterns, which can be used to fabricate planar interconnects. More recently, various groups have demonstrated electrical interconnects from laser-printed 3D structures. The laser printing of these interconnects takes place through aggregation of voxels of either molten metal or of pastes containing dispersed metallic particles. However, the generated 3D structures do not posses the same metallic conductivity as a bulk metal interconnect of the same cross-section and length as those formed by wire bonding or tab welding. An alternative is to laser transfer entire 3D structures using a technique known as lase-and-place. Lase-and-place is a LIFT process whereby whole components and parts can be transferred from a donor substrate onto a desired location with one single laser pulse. This paper will describe the use of LIFT to laser print freestanding, solid metal foils or beams precisely over the contact pads of discrete devices to interconnect them into fully functional circuits. Furthermore, this paper will also show how the same laser can be used to bend or fold the bulk metal foils prior to transfer, thus forming compliant 3D structures able to provide strain relief for the circuits under flexing or during motion from thermal mismatch. These interconnect "ridges" can span wide gaps (on the order of a millimeter) and accommodate height differences of tens of microns between adjacent devices. Examples of these laser printed 3D metallic bridges and their role in the development of next generation electronics by additive manufacturing will be presented.

High temperature corrosion of metallic interconnects in solid oxide fuel cells

International Nuclear Information System (INIS)

Bastidas, D. M.

2006-01-01

Research and development has made it possible to use metallic interconnects in solid oxide fuel cells (SOFC) instead of ceramic materials. The use of metallic interconnects was formerly hindered by the high operating temperature, which made the interconnect degrade too much and too fast to be an efficient alternative. When the operating temperature was lowered, the use of metallic interconnects proved to be favourable since they are easier and cheaper to produce than ceramic interconnects. However, metallic interconnects continue to be degraded despite the lowered temperature, and their corrosion products contribute to electrical degradation in the fuel cell. coatings of nickel, chromium, aluminium, zinc, manganese, yttrium or lanthanum between the interconnect and the electrodes reduce this degradation during operation. (Author) 66 refs

Numerical simulation of direct-drive ICF ignition in spherical geometry

International Nuclear Information System (INIS)

Yu Xiaojin

2006-01-01

The basic condition required for achieving central ignition is producing a hot spot with 10 keV temperature and 0.3 g/cm 2 surface density. Growth of hydrodynamic instability during deceleration phase will destroy the symmetric-drive, reduce the volume of central hot spot and make a harmful effect on ignition. Based on the LARED-S code, considering the thermonuclear reaction and α-particle heating, a numerical study of direct-drive ICF in spherical geometry is made. One-dimensional results agree well with the NIF ignition target designs, and show that the α-particle heating plays an important role in marginal ignition. Two-dimensional results show that the growth of hydrodynamic instability during deceleration phase makes a harmful effect on ignition. (authors)

Production and characterisation of SLID interconnected n-in-p pixel modules with 75 μm thin silicon sensors

Energy Technology Data Exchange (ETDEWEB)

Andricek, L. [Halbleiterlabor der Max-Planck-Gesellschaft, Otto Hahn Ring 6, D-81739 München (Germany); Beimforde, M.; Macchiolo, A.; Moser, H.-G. [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 München (Germany); Nisius, R., E-mail: Richard.Nisius@mpp.mpg.de [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 München (Germany); Richter, R.H. [Halbleiterlabor der Max-Planck-Gesellschaft, Otto Hahn Ring 6, D-81739 München (Germany); Terzo, S.; Weigell, P. [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), Föhringer Ring 6, D-80805 München (Germany)

2014-09-11

The performance of pixel modules built from 75 μm thin silicon sensors and ATLAS read-out chips employing the Solid Liquid InterDiffusion (SLID) interconnection technology is presented. This technology, developed by the Fraunhofer EMFT, is a possible alternative to the standard bump-bonding. It allows for stacking of different interconnected chip and sensor layers without destroying the already formed bonds. In combination with Inter-Chip-Vias (ICVs) this paves the way for vertical integration. Both technologies are combined in a pixel module concept which is the basis for the modules discussed in this paper. Mechanical and electrical parameters of pixel modules employing both SLID interconnections and sensors of 75 μm thickness are covered. The mechanical features discussed include the interconnection efficiency, alignment precision and mechanical strength. The electrical properties comprise the leakage currents, tuning characteristics, charge collection, cluster sizes and hit efficiencies. Targeting at a usage at the high luminosity upgrade of the LHC accelerator called HL-LHC, the results were obtained before and after irradiation up to fluences of 10{sup 16}n{sub eq}/cm{sup 2}.

Physics-based modeling of live wildland fuel ignition experiments in the Forced Ignition and Flame Spread Test apparatus

Science.gov (United States)