WorldWideScience

Sample records for photon processes opportunities

  1. High-flux solar photon processes: Opportunities for applications

    Energy Technology Data Exchange (ETDEWEB)

    Steinfeld, J.I.; Coy, S.L.; Herzog, H.; Shorter, J.A.; Schlamp, M.; Tester, J.W.; Peters, W.A. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

    1992-06-01

    The overall goal of this study was to identify new high-flux solar photon (HFSP) processes that show promise of being feasible and in the national interest. Electric power generation and hazardous waste destruction were excluded from this study at sponsor request. Our overall conclusion is that there is promise for new applications of concentrated solar photons, especially in certain aspects of materials processing and premium materials synthesis. Evaluation of the full potential of these and other possible applications, including opportunities for commercialization, requires further research and testing. 100 refs.

  2. Inverse photon-photon processes

    International Nuclear Information System (INIS)

    Carimalo, C.; Crozon, M.; Kesler, P.; Parisi, J.

    1981-12-01

    We here consider inverse photon-photon processes, i.e. AB → γγX (where A, B are hadrons, in particular protons or antiprotons), at high energies. As regards the production of a γγ continuum, we show that, under specific conditions the study of such processes might provide some information on the subprocess gg γγ, involving a quark box. It is also suggested to use those processes in order to systematically look for heavy C = + structures (quarkonium states, gluonia, etc.) showing up in the γγ channel. Inverse photon-photon processes might thus become a new and fertile area of investigation in high-energy physics, provided the difficult problem of discriminating between direct photons and indirect ones can be handled in a satisfactory way

  3. Photonic Quantum Information Processing

    International Nuclear Information System (INIS)

    Walther, P.

    2012-01-01

    The advantage of the photon's mobility makes optical quantum system ideally suited for delegated quantum computation. I will present results for the realization for a measurement-based quantum network in a client-server environment, where quantum information is securely communicated and computed. Related to measurement-based quantum computing I will discuss a recent experiment showing that quantum discord can be used as resource for the remote state preparation, which might shine new light on the requirements for quantum-enhanced information processing. Finally, I will briefly review recent photonic quantum simulation experiments of four frustrated Heisenberg-interactions spins and present an outlook of feasible simulation experiments with more complex interactions or random walk structures. As outlook I will discuss the current status of new quantum technology for improving the scalability of photonic quantum systems by using superconducting single-photon detectors and tailored light-matter interactions. (author)

  4. Hard processes in photon-photon interactions

    International Nuclear Information System (INIS)

    Duchovni, E.

    1985-03-01

    In this thesis, the existence of hard component in two-photon collisions is investigated. Due to the relative simplicity of the photon, such processes can be exactly calculated in QCD. Untagged (low Q 2 ) two-photon events are used. This leads to relatively high statistics, but to severe background problem due mainly to e + e - annihilation. The background contamination is reduced to a tolerable level using a special set of cuts. Moreover, the remaining contamination is shown to be calculable with a small systematic error. A large number of events of the hard ''γγ'' type is found. An attempt to explain these events using the simplest QCD diagram (the Born term) is done. This process is found to be capable of explaining only a 1/4 of the data. Other options like the constituent intercharge model, integer charged quarks, and higher order diagrams are therefore also discussed. The large cross-section for the production of ρ 0 ρ 0 pairs in ''γγ'' collisions has not been understood yet. Inorder to look at closely related processes, a search for φρ 0 and φφ was initiated. The cross-section for θπ + π - was found to be sizeable. Only upper limits for the production of φρ 0 and φφ are obtained

  5. Photon technology. Laser process technology; Photon technology. Laser process gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    For developing laser process technology by interaction between substance and photon, the present state, system, R and D issues and proposal of such technology were summarized. Development of the photon technology aims at the modification of bonding conditions of substances by quantum energy of photon, and the new process technology for generating ultra- high temperature and pressure fields by concentrating photon on a minute region. Photon technology contributes to not only the conventional mechanical and thermal forming and removal machining but also function added machining (photon machining) in quantum level and new machining technology ranging from macro- to micro-machining, creating a new industrial field. This technology extends various fields from the basis of physics and chemistry to new bonding technology. Development of a compact high-quality high-power high-efficiency photon source, and advanced photon transmission technology are necessary. The basic explication of an unsolved physicochemical phenomenon related to photon and substance, and development of related application technologies are essential. 328 refs., 147 figs., 13 tabs.

  6. Photon technology. Laser processing technology; Photon technology. Laser process gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Survey has been conducted to develop laser processing technology utilizing the interaction between substance and photon. This is a part of the leading research on photon technology development. The photon technology development is aimed at novel technology development highly utilizing the quantum nature of photons. In the field of laser processing, high quality photons are used as tools, special functions of atoms and molecules will be discovered, and processing for functional fabrication (photon machining) will be established. A role of laser processing in industries has become significant, which is currently spreading not only into cutting and welding of materials and scalpels but also into such a special field as ultrafine processing of materials. The spreading is sometimes obstructed due to the difficulty of procurement of suitable machines and materials, and the increase of cost. The purpose of this study is to develop the optimal laser technology, to elucidate the interaction between substance and photon, and to develop the laser system and the transmission and regulation systems which realize the optimal conditions. 387 refs., 115 figs., 25 tabs.

  7. Inclusive hard processes in photon-photon and photon-proton interactions

    OpenAIRE

    Glasman, Claudia

    1999-01-01

    Measurements of jet, prompt photon, high-pT hadron and heavy quark production in photon-induced processes provide tests of QCD and are sensitive to the photon parton densities. A review of the latest experimental results in photon-photon and photon-proton interactions is presented. Next-to-leading-order QCD calculations for these measurements are discussed.

  8. Supercritical fluids processing: emerging opportunities

    International Nuclear Information System (INIS)

    Kovaly, K.A.

    1985-01-01

    This publication on the emerging opportunities of supercritical fluids processing reveals the latest research findings and development trends in this field. These findings and development trends are highlighted, and the results of applications of technology to the business of supercritical fluids are reported. Applications of supercritical fluids to chemical intermediates, environmental applications, chemical reactions, food and biochemistry processing, and fuels processing are discussed in some detail

  9. Progress and Opportunities in Soft Photonics and Biologically Inspired Optics.

    Science.gov (United States)

    Kolle, Mathias; Lee, Seungwoo

    2018-01-01

    Optical components made fully or partially from reconfigurable, stimuli-responsive, soft solids or fluids-collectively referred to as soft photonics-are poised to form the platform for tunable optical devices with unprecedented functionality and performance characteristics. Currently, however, soft solid and fluid material systems still represent an underutilized class of materials in the optical engineers' toolbox. This is in part due to challenges in fabrication, integration, and structural control on the nano- and microscale associated with the application of soft components in optics. These challenges might be addressed with the help of a resourceful ally: nature. Organisms from many different phyla have evolved an impressive arsenal of light manipulation strategies that rely on the ability to generate and dynamically reconfigure hierarchically structured, complex optical material designs, often involving soft or fluid components. A comprehensive understanding of design concepts, structure formation principles, material integration, and control mechanisms employed in biological photonic systems will allow this study to challenge current paradigms in optical technology. This review provides an overview of recent developments in the fields of soft photonics and biologically inspired optics, emphasizes the ties between the two fields, and outlines future opportunities that result from advancements in soft and bioinspired photonics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Modification of equivalent photon approximation (EPA) for resolved photon processes

    International Nuclear Information System (INIS)

    Drees, M.; Godbole, R.M.

    1995-05-01

    The authors propose a modification of the equivalent photon approximation (EPA) for processes which involve the parton content of the photon, to take into account the suppression of the photonic parton fluxes due to the virtuality of the photon. They present simple, physically motivated ansaetze to model this suppression and show that even though the parton content of the electron no longer factorizes into an electron flux function and photon structure function, it is still possible to express it as a single integral. They also show that for the TRISTAN (transposable ring intersecting storage accelerators in Nippon) experiments its effects can be numerically of the same size as that of the NLO corrections. Further, it is discussed a possible measurements at HERA (hadron electron ring an large), which can be provide an experimental handle on the effect the authors model through their ansaetze

  11. Multiple photon infrared processes in polyatomic molecules

    International Nuclear Information System (INIS)

    Harrison, R.G.; Butcher, S.R.

    1980-01-01

    This paper reviews current understanding of the process of multiple photon excitation and dissociation of polyatomic molecules, whereby in the presence of an intense infrared laser field a molecule may absorb upwards of 30 photons. The application of this process to new photochemistry and in particular laser isotope separation is also discussed. (author)

  12. Photons emission processes in electron scattering

    International Nuclear Information System (INIS)

    Soto Vargas, C.W.

    1996-01-01

    The investigations involving the scattering sections arising in virtual an real photon emission processes of electron and positron scattering by an atomic nucleus, have the need for thorough and complete calculations of the virtual photon spectrum and then introduce the distorted wave formulation, which is mathematically involved an numerically elaborated, but accessible to its use in experimental electron scattering facilities. (author) [es

  13. Photon-photon and photon-hadron processes in relativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Baron, N.C.

    1993-11-01

    Photon-photon and photon-hadron interactions in relativistic heavy ion collisions are studied in the framework of the impact parameter dependent equivalent photon approximation. Improvements of this method, like formfactor inclusion and geometrical modifications are developed. In disruptive relativistic heavy ion collisions where the heavy ions overlapp during the collision, electromagnetic processes are an important background to other mechanisms. In peripheral (non-disruptive) relativistic heavy ion collisions where the ions pass each other without strong interactions, the electromagnetic processes can be studied in their pure form. The lepton pair production is an important diagnostic tool in relativistic heavy ion collisions. The coherent γγ lepton pair production is therefore extensively studied in disruptive but also in non-disruptive collisions. The effects of strong interactions on the coherent γγ lepton pair production in disruptive collisions are discussed in terms of a simple stopping model. Coherent γγ dielectron production contributes to the dilepton production in high energy hadron-hadron collisions. As an example, the coherent dielectron production in π - p collisions is studied in terms of the equivalent photon approximation. Peripheral ultrarelativistic heavy ion collisions open up new possibilities for γγ physics. Taking into account γA background reactions, typical γγ processes in the relevant invariant mass ranges are discussed. The extreme high energy part of the equivalent photon spectrum leads to hard photon-parton reactions. As a potential tool to investigate the gluon distribution function of nucleons, thee q anti q production via the γg fusion in ultrarelativistic heavy ion collisions is studied. It is the purpose of this work to investigate how photon-photon and photon-hadron reactions in relativistic heavy ion collisions may contribute to the understanding of QCD and the standard model. (orig.) [de

  14. Process mining : overview and opportunities

    NARCIS (Netherlands)

    Aalst, van der W.M.P.

    2012-01-01

    Over the last decade, process mining emerged as a new research ¿eld that focuses on the analysis of processes using event data. Classical data mining techniques such as classi¿cation, clustering, regression, association rule learning, and sequence/episode mining do not focus on business process

  15. Quantum information processing with atoms and photons

    International Nuclear Information System (INIS)

    Monroe, C.

    2003-01-01

    Quantum information processors exploit the quantum features of superposition and entanglement for applications not possible in classical devices, offering the potential for significant improvements in the communication and processing of information. Experimental realization of large-scale quantum information processors remains a long term vision, as the required nearly pure quantum behaviour is observed only in exotic hardware such as individual laser-cooled atoms and isolated photons. But recent theoretical and experimental advances suggest that cold atoms and individual photons may lead the way towards bigger and better quantum information processors, effectively building mesoscopic versions of Schroedinger's cat' from the bottom up. (author)

  16. Opportunities and challenges for photonics in the automotive

    Science.gov (United States)

    Mounier, Eric; Eloy, Jean-Christophe; Jourdan, David

    2005-02-01

    In the future, photonics will enable the marketing of new functions in cars to make them more secure, more fuel-efficient with improved design. Today, there are already photonics devices used in cars such as HB LEDs for brake or interior lights, and optical rain sensors for automatic wipers. Moreover, optical multiplexing for multimedia applications and head-up displays are now starting to be implemented in high-end cars and some more complex devices are already at the prototyping level. This is the case for example for driver information flat panel displays or optical sensors for occupant sensing. This paper gives an overview of the current and future optical applications in cars. So far, applications of displays, lighting, security and datacom are driving the market for photonics in cars. Moreover, car design is also one of the most important market drivers in automobile. Then, photonics could also become a strategic imperative for a company in the design of new cars that will emphasize differentiation from existing competitors. Lighting could then become a signature of the car manufacturer thanks to photonics technology.

  17. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying Biomedical Photonics, spectroscopy and microscopy This volume discusses biomedical photonics, spectroscopy and microscopy, the basic physical principles underlying the technology and its applications. The topics discussed in this volume are: Biophotonics; Fluorescence and Phosphorescence; Medical Photonics; Microscopy; Nonlinear Optics; Ophthalmic Technology; Optical Tomography; Optofluidics; Photodynamic Therapy; Image Processing; Imaging Systems; Sensors; Single Molecule Detection; Futurology in Photonics. Comprehensive and accessible cov

  18. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    This book covers modern photonics accessibly and discusses the basic physical principles underlying all the applications and technology of photonicsThis volume covers the basic physical principles underlying the technology and all applications of photonics from statistical optics to quantum optics. The topics discussed in this volume are: Photons in perspective; Coherence and Statistical Optics; Complex Light and Singular Optics; Electrodynamics of Dielectric Media; Fast and slow Light; Holography; Multiphoton Processes; Optical Angular Momentum; Optical Forces, Trapping and Manipulation; Pol

  19. Squeezing, photon bunching, photon antibunching and nonclassical photon statistics in degenerate hyper Raman processes

    International Nuclear Information System (INIS)

    Sen, Biswajit; Mandal, Swapan

    2007-01-01

    An initially prepared coherent state coupled to a second-order nonlinear medium is responsible for stimulated and spontaneous hyper Raman processes. By using an intuitive approach based on perturbation theory, the Hamiltonian corresponding to the hyper Raman processes is analytically solved to obtain the temporal development of the field operators. It is true that these analytical solutions are valid for small coupling constants. However, the interesting part is that these solutions are valid for reasonably large time. Hence, the present analytical solutions are quite general and are fresh compared to those solutions under short-time approximations. By exploiting the analytical solutions of field operators for various modes, we investigate the squeezing, photon antibunching and nonclassical photon statistics for pure modes of the input coherent light responsible for hyper Raman processes. At least in one instance (stimulated hyper Raman processes for vibration phonon mode), we report the simultaneous appearance of classical (photon bunching) and nonclassical (squeezing) effects of the radiation field responsible for hyper Raman processes

  20. Recursive relations for processes with n photons of noncommutative QED

    International Nuclear Information System (INIS)

    Jafari, Abolfazl

    2007-01-01

    Recursion relations are derived in the sense of Berends-Giele for the multi-photon processes of noncommutative QED. The relations concern purely photonic processes as well as the processes with two fermions involved, both for arbitrary number of photons at tree level. It is shown that despite of the dependence of noncommutative vertices on momentum, in contrast to momentum-independent color factors of QCD, the recursion relation method can be employed for multi-photon processes of noncommutative QED

  1. Hadron production in photon-photon processes at the ILC

    Energy Technology Data Exchange (ETDEWEB)

    Sasikumar, Kollassery Swathi [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany); Universitaet Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); Berggren, Carl Mikael; List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany)

    2016-07-01

    The International linear Collider (ILC) is a proposed e{sup +}e{sup -} collider, designed to operate at energies from 91 GeV upto about 500 GeV (with the possibility to upgrade to 1 TeV). The highly clean conditions provided by the ILC enables us to make high precision measurements e.g. of the Higgs boson and to search for new particles. In addition to the desired e{sup +}e{sup -} collisions, parasitic collisions of real and virtual photons radiated off the e{sup ±} beams occur at rates of a few γγ collisions per bunch crossing. The γγ centre of mass energies reach from few 100 MeV up to the full e{sup +}e{sup -} centre of mass energy. For all these energies, in particular the production of hadrons,needs to be modelled correctly in order to estimate the impact of these backgrounds which pile-up on each e{sup +}e{sup -} event. This contribution discusses the current simulations of γγ → hadron processes, evaluates their impact on the detector and introduces new methods to remove them from the interesting physics events.

  2. Excitonic and photonic processes in materials

    CERN Document Server

    Williams, Richard

    2015-01-01

    This book is expected to present state-of-the-art understanding of a selection of excitonic and photonic processes in useful materials from semiconductors to insulators to metal/insulator nanocomposites, both inorganic and organic.  Among the featured applications are components of solar cells, detectors, light-emitting devices, scintillators, and materials with novel optical properties.  Excitonic properties are particularly important in organic photovoltaics and light emitting devices, as also in questions of the ultimate resolution and efficiency of new-generation scintillators for medical diagnostics,  border security, and nuclear nonproliferation.  Novel photonic and optoelectronic applications benefit from new material combinations and structures to be discussed.

  3. Self-collimation in photonic crystals. Applications and opportunities

    International Nuclear Information System (INIS)

    Noori, Mina; Soroosh, Mohammad; Baghban, Hamed

    2018-01-01

    A comprehensive review considering recent advances in self-collimation and its applications in optical integration is covered in the current article. Self-collimation is compared to the conventional technique of photonic bandgap engineering to control the light propagation in photonic crystal-based structures. It is fully discussed how the self-collimation phenomenon can be tailored to be independent of the incident angle and polarization. This adds substantial flexibility to the structure to overcome light coupling challenges and simultaneously aids in the omission of bulk and challenging elements, including polarizers and lenses from optical integrated circuits. Additionally, designed structures have the potential to be rescaled to operate in any desired frequency range thanks to the scalability rule in the field of electromagnetics. Moreover, it is shown that one can boost the coupling efficiency by applying an anti-reflection property to the structure, which provides not only efficient index matching but also the matching between external waves with uniform amplitude and Bloch waves with periodic amplitude. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Two photon processes in surface photovoltage spectroscopy

    International Nuclear Information System (INIS)

    Craig, R.P.; Thurgate, S.M.

    1996-01-01

    Full text: A significant mid-gap effect has been found in Surface Photovoltage Spectroscopy measurements of cleaved GaAs, InP and Si wafer which is normally interpreted as arising from transitions between surface states and band edges. This large mid-gap effect common to various materials is puzzling as such a high proportion of mid-gap states seems unlikely. Most theories of surface states predict states that tail from the band edges into the gap or states that have a well defined energy in the gap. None propose a large state exactly at E G /2. We recently investigated the variation in SPS spectra with flux density. We find a non-linear correlation in the magnitude of Band-Bending arising from mid-gap and band-gap photon energies. We suggest that the mid-gap feature is due to a two photon absorption process leading to carrier pair generation mediated by mid-gap states in the continuum of band-gap surface states

  5. Challenges and opportunities for the next generation of photon regeneration experiments

    International Nuclear Information System (INIS)

    Ringwald, Andreas

    2010-03-01

    Photon regeneration experiments searching for signatures of oscillations of photons into hypothetical very weakly interacting ultra-light particles, such as axions, axion-like and hiddensector particles, have improved their sensitivity considerably in recent years. Important progress in laser and detector technology as well as recycling of available magnets from accelerators may allow a big further step in sensitivity such that, for the first time, laser light shining through a wall experiments will explore territory in parameter space that has not been excluded yet by astrophysics and cosmology.We review these challenges and opportunities for the next generation experiments. (orig.)

  6. Color management: printing processes - opportunities and limitations

    Science.gov (United States)

    Ingram, Samuel T.

    2002-06-01

    Digital tools have impacted traditional methods employed to reproduce color images during the past decade. The shift from a purely photomechanical process in color reproduction to colorimetric reproduction offers tremendous opportunity in the graphic arts industry. But good things do not necessarily come to all in the same package. Printing processes possess different reproduction attributes: tone reproduction, gray balance and color correction requirements are as different as the ingredient sets selected for color reproduction. This paper will provide insight toward understanding advantages and limitations offered by the new digital technologies in printing, publishing and packaging. For the past five years the Clemson University Graphic Communications Department has conducted numerous color projects using the new digital colorimetric tools during the previous decade. Several approaches have been used including experimental research and typical production workflows. The use of colorimetric data in color reproduction has given an opportunity to realize real gains in color use, predictability and consistency. Meeting an image's separation and reproduction requirements for a specified printing process can involve disruption of the anticipated workflow. Understanding the printing process requirements and the fit within the specifications of a colorimetric workflow are critical to the successful adoption of a color managed workflow. The paper will also provide an insight into the issues and challenges experienced with a color managed workflow. The printing processes used include offset litho, narrow and wide-web flexography (paper, liner board, corrugated and film), screen printing (paper board and polycarbonates), and digital imaging with toner, ink and inkjet systems. A proposal for technology integration will be the focus of the presentation drawn from documented experiences in over 300 applications of color management tools. Discussion will include the structure of

  7. Photon imaging using post-processed CMOS chips

    NARCIS (Netherlands)

    Melai, J.

    2010-01-01

    This thesis presents our work on an integrated photon detector made by post-processing of CMOS sensor arrays. The aim of the post-processing is to combine all elements of the detector into a single monolithic device. These elements include a photocathode to convert photon radiation into electronic

  8. Signal processing: opportunities for superconductive circuits

    International Nuclear Information System (INIS)

    Ralston, R.W.

    1985-01-01

    Prime motivators in the evolution of increasingly sophisticated communication and detection systems are the needs for handling ever wider signal bandwidths and higher data processing speeds. These same needs drive the development of electronic device technology. Until recently the superconductive community has been tightly focused on digital devices for high speed computers. The purpose of this paper is to describe opportunities and challenges which exist for both analog and digital devices in a less familiar area, that of wideband signal processing. The function and purpose of analog signal-processing components, including matched filters, correlators and Fourier transformers, will be described and examples of superconductive implementations given. A canonic signal-processing system is then configured using these components in combination with analog/digital converters and digital output circuits to highlight the important issues of dynamic range, accuracy and equivalent computation rate. Superconductive circuits hold promise for processing signals of 10-GHz bandwidth. Signal processing systems, however, can be properly designed and implemented only through a synergistic combination of the talents of device physicists, circuit designers, algorithm architects and system engineers. An immediate challenge to the applied superconductivity community is to begin sharing ideas with these other researchers

  9. SIGNAL PROCESSING UTILIZING RADIO FREQUENCY PHOTONICS

    Science.gov (United States)

    2017-09-07

    has many advantages over these electronic counterparts. The ability to cover larger bandwidths, immunity to electromagnetic interference, low weight...is unlimited. 4.1 RF Photonics Sampling with Electronic ADCs Figure 7 shows a photonic sampling scheme. The amplitude of the pulses from a laser are...modified by the RF signal to be sampled. The pulses are time demultiplexed and passed to multiple ADCs. The hybrid configuration combines parallel

  10. Two-photon processes in highly charged ions

    International Nuclear Information System (INIS)

    Jahrsetz, Thorsten

    2015-01-01

    Two-photon processes are atomic processes in which an atom interacts simultaneously with two photons. Such processes describe a wide range of phenomena, such as two-photon decay and elastic or inelastic scattering of photons. In recent years two-photon processes involving highly charged heavy ions have become an active area of research. Such studies do not only consider the total transition or scattering rates but also their angular and polarization dependence. To support such examinations in this thesis I present a theoretical framework to describe these properties in all two-photon processes with bound initial and final states and involving heavy H-like or He-like ions. I demonstrate how this framework can be used in some detailed studies of different two-photon processes. Specifically a detailed analysis of two-photon decay of H-like and He-like ions in strong external electromagnetic fields shows the importance of considering the effect of such fields for the physics of such systems. Furthermore I studied the elastic Rayleigh as well as inelastic Raman scattering by heavy H-like ions. I found a number of previously unobserved phenomena in the angular and polarization dependence of the scattering cross-sections that do not only allow to study interesting details of the electronic structure of the ion but might also be useful for the measurement of weak physical effects in such systems.

  11. Two-photon processes in highly charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Jahrsetz, Thorsten

    2015-03-05

    Two-photon processes are atomic processes in which an atom interacts simultaneously with two photons. Such processes describe a wide range of phenomena, such as two-photon decay and elastic or inelastic scattering of photons. In recent years two-photon processes involving highly charged heavy ions have become an active area of research. Such studies do not only consider the total transition or scattering rates but also their angular and polarization dependence. To support such examinations in this thesis I present a theoretical framework to describe these properties in all two-photon processes with bound initial and final states and involving heavy H-like or He-like ions. I demonstrate how this framework can be used in some detailed studies of different two-photon processes. Specifically a detailed analysis of two-photon decay of H-like and He-like ions in strong external electromagnetic fields shows the importance of considering the effect of such fields for the physics of such systems. Furthermore I studied the elastic Rayleigh as well as inelastic Raman scattering by heavy H-like ions. I found a number of previously unobserved phenomena in the angular and polarization dependence of the scattering cross-sections that do not only allow to study interesting details of the electronic structure of the ion but might also be useful for the measurement of weak physical effects in such systems.

  12. Modular manufacturing processes : Status, challenges, and opportunities

    NARCIS (Netherlands)

    Baldea, Michael; Edgar, Thomas F.; Stanley, Bill L.; Kiss, Anton A.

    2017-01-01

    Chemical companies are constantly seeking new, high-margin growth opportunities, the majority of which lie in high-grade, specialty chemicals, rather than in the bulk sector. To realize these opportunities, manufacturers are increasingly considering decentralized, flexible production facilities:

  13. Azimuthal asymmetry in processes of nonlinear QED for linearly polarized photon

    International Nuclear Information System (INIS)

    Bajer, V.N.; Mil'shtejn, A.I.

    1994-01-01

    Cross sections of nonlinear QED processes (photon-photon scattering, photon splitting in a Coulomb field, and Delbrueck scattering) are considered for linearly polarized initial photon. The cross sections have sizeable azimuthal asymmetry. 15 refs.; 3 figs

  14. Quantum information processing with mesoscopic photonic states

    DEFF Research Database (Denmark)

    Madsen, Lars Skovgaard

    2012-01-01

    photon numbers and the states where one of Stokes parameters is highly excited. To describe the polarization of these state we introduce several new polarization measures which take into account the covariance of the polarization and resolve the polarization manifolds. We experimentally demonstrate...

  15. Inverse opal photonic crystal of chalcogenide glass by solution processing.

    Science.gov (United States)

    Kohoutek, Tomas; Orava, Jiri; Sawada, Tsutomu; Fudouzi, Hiroshi

    2011-01-15

    Chalcogenide opal and inverse opal photonic crystals were successfully fabricated by low-cost and low-temperature solution-based process, which is well developed in polymer films processing. Highly ordered silica colloidal crystal films were successfully infilled with nano-colloidal solution of the high refractive index As(30)S(70) chalcogenide glass by using spin-coating method. The silica/As-S opal film was etched in HF acid to dissolve the silica opal template and fabricate the inverse opal As-S photonic crystal. Both, the infilled silica/As-S opal film (Δn ~ 0.84 near λ=770 nm) and the inverse opal As-S photonic structure (Δn ~ 1.26 near λ=660 nm) had significantly enhanced reflectivity values and wider photonic bandgaps in comparison with the silica opal film template (Δn ~ 0.434 near λ=600 nm). The key aspects of opal film preparation by spin-coating of nano-colloidal chalcogenide glass solution are discussed. The solution fabricated "inorganic polymer" opal and the inverse opal structures exceed photonic properties of silica or any organic polymer opal film. The fabricated photonic structures are proposed for designing novel flexible colloidal crystal laser devices, photonic waveguides and chemical sensors. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. Opportunities of Bamboo for Industrial Processes

    NARCIS (Netherlands)

    Janssen, J.J.A.; Erkelens, P.A.; Jonge, S. de; Vliet, A.A.M. van

    2000-01-01

    Bamboo as resource for industrial raw material has many opportunities: It contains a 40 percent cellulose, with a fibre length of 3 to 4 mm, more than wood. This can be used as pulp in the paper industry or as cellulose. The fibres also can be used for fibreboard or for furniture parts. Bamboo

  17. Verification of photon-production processing techniques

    International Nuclear Information System (INIS)

    Barrett, R.J.; Ford, W.E. III; Gohar, Y.; Bohn, T.S.; MacFarlane, R.E.; Boicourt, R.M.

    1979-01-01

    Several laboratories have independently developed computer codes which use evaluated data from the ENDF/B file to produce group-averaged cross sections and transfer matrices for neutron-induced photon production. There have been several instances in which these codes have produced discrepant data sets, and thereby cast doubt on the validity of all the codes. For a series of specified test cases, the results from three of these codes (NJOY, LAPHNGAS, and MACK-IV) were systematically compared with each other and with hand calculations. Several shortcomings in the codes were discovered and repaired. One major difference of philosophy was resolved. Consequently, the codes have arrived at substantial agreement on all of the nearly 1200 nonzero group constants calculated in the study. 4 figures, 1 table

  18. Ultra-high-speed Optical Signal Processing using Silicon Photonics

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Ji, Hua; Jensen, Asger Sellerup

    with a photonic layer on top to interconnect them. For such systems, silicon is an attractive candidate enabling both electronic and photonic control. For some network scenarios, it may be beneficial to use optical on-chip packet switching, and for high data-density environments one may take advantage...... of the ultra-fast nonlinear response of silicon photonic waveguides. These chips offer ultra-broadband wavelength operation, ultra-high timing resolution and ultra-fast response, and when used appropriately offer energy-efficient switching. In this presentation we review some all-optical functionalities based...... on silicon photonics. In particular we use nano-engineered silicon waveguides (nanowires) [1] enabling efficient phasematched four-wave mixing (FWM), cross-phase modulation (XPM) or self-phase modulation (SPM) for ultra-high-speed optical signal processing of ultra-high bit rate serial data signals. We show...

  19. Photonic Interrogation and Control of Nano Processes

    Science.gov (United States)

    Jassemnejad, Baha

    2003-01-01

    able to generate laser tweezers modes of different orbital angular momentum using a spatial light modulator incorporated into a laser tweezers system. The motivation for investigating these types of modes stems from being able to spin particles at high speeds and also to orient two particles in separate traps and then join them together. Also, there has been recent intense interest on fundamental physics research on orbital angular momentum of light. The fact that circularly polarized light may have associated with it angular momentum that relates to the spin of individual photons (spin 0 for the plane polarized light, spin +1 for the right-circularly polarized light and spin -1 for the left-circularly polarized light) was first demonstrated by Beth in 1936. Orbital angular momentum is, however, distinct from spin in that the spin angular momentum of light is intrinsically linked to the behavior of the electric field in the light whereas orbital angular momentum is a consequence of inclined wavefronts. In 1992 L. Allen, et al showed that the Laguerre-Gaussian (LG) modes could possess well-defined orbital angular momentum that can exceed 1 planck's constant, i.e. l plancks constant per photon, where l is the azimuthal index of the mode.

  20. On-chip, photon-number-resolving, telecommunication-band detectors for scalable photonic information processing

    Energy Technology Data Exchange (ETDEWEB)

    Gerrits, Thomas; Lita, Adriana E.; Calkins, Brice; Tomlin, Nathan A.; Fox, Anna E.; Linares, Antia Lamas; Mirin, Richard P.; Nam, Sae Woo [National Institute of Standards and Technology, Boulder, Colorado, 80305 (United States); Thomas-Peter, Nicholas; Metcalf, Benjamin J.; Spring, Justin B.; Langford, Nathan K.; Walmsley, Ian A. [Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Gates, James C.; Smith, Peter G. R. [Optoelectronics Research Centre, University of Southampton, Highfield SO17 1BJ (United Kingdom)

    2011-12-15

    Integration is currently the only feasible route toward scalable photonic quantum processing devices that are sufficiently complex to be genuinely useful in computing, metrology, and simulation. Embedded on-chip detection will be critical to such devices. We demonstrate an integrated photon-number-resolving detector, operating in the telecom band at 1550 nm, employing an evanescently coupled design that allows it to be placed at arbitrary locations within a planar circuit. Up to five photons are resolved in the guided optical mode via absorption from the evanescent field into a tungsten transition-edge sensor. The detection efficiency is 7.2{+-}0.5 %. The polarization sensitivity of the detector is also demonstrated. Detailed modeling of device designs shows a clear and feasible route to reaching high detection efficiencies.

  1. Food processing with electrically generated photon irradiation

    International Nuclear Information System (INIS)

    Matthews, S.M.

    1983-01-01

    A conceptual design for a portable electric food irradiation processing machine is presented and analyzed for cost assuming the required accelerators are available for $1.5 million each. It is shown that food can be processed to 1 kGy for a price of $5.98/ton

  2. Photonic Crystal Nanocavity Devices for Nonlinear Signal Processing

    DEFF Research Database (Denmark)

    Yu, Yi

    , membranization of InP/InGaAs structure and wet etching. Experimental investigation of the switching dynamics of InP photonic crystal nanocavity structures are carried out using short-pulse homodyne pump-probe techniques, both in the linear and nonlinear region where the cavity is perturbed by a relatively small......This thesis deals with the investigation of InP material based photonic crystal cavity membrane structures, both experimentally and theoretically. The work emphasizes on the understanding of the physics underlying the structures’ nonlinear properties and their applications for all-optical signal...... processing. Based on the previous fabrication recipe developed in our III-V platform, several processing techniques are developed and optimized for the fabrication of InP photonic crystal membrane structures. Several key issues are identified to ensure a good device quality such as air hole size control...

  3. Food processing with electrically generated photon irradiation

    International Nuclear Information System (INIS)

    Matthews, S.M.

    1985-01-01

    Economic constraints require that a food irradiation processing facility have a throughput of approximately 1 MGy ton/day (0.91 MGy m.t./day) requiring 3 MegaCuries (MCi) of cobalt-60 at each site. This requirement means that the total world amount of cobalt-60 would have to be increased by about 60 percent just to handle the California almond and raisin crop during peak season. It is doubtful that public opinion would allow the increased distribution of radioactive isotopes, with the resultant burden upon the transportation networks, as a price to be paid to eat irradiated food. Electric sources have characteristics that allow the production of more penetrating, uniform, and efficient radiation that is available from nuclear isotopes. The heart of the electric radiation source is the electron accelerator. At present, there are no accelerators commercially available that can meet the requirements for food irradiation processing. However, the U.S. Department of Defense-funded beam weapons programs have provided a very promising accelerator technology at the Lawrence Livermore National Laboratory. If this technology were to be commercialized, it appears that the required accelerators would be available for US$1.5 million apiece, and quite possibly for less than this amount. A conceptual design for a portable electric food irradiation processing machine is presented and analyzed for cost, assuming the required accelerators are available for $1.5 million each. It is shown that food can be processed for 1 kGy for a price of $5.98/ton ($6.59/m.t.)

  4. Time evolution of absorption process in nonlinear metallic photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahi R.; Hatef, Ali [Department of Physics and Astronomy, University of Western Ontario, London (Canada)

    2009-05-15

    The time evolution of the absorption coefficient in metallic photonic crystals has been studied numerically. These crystals are made from metallic spheres which are arranged periodically in air. The refractive index of the metallic spheres depends on the plasma frequency. Probe and pump fields are applied to monitor the absorption process. Ensembles of three-level particles are embedded in the crystal. Nanoparticles are interacting with the metallic crystals via the electron-photon interaction. It is found that when the resonance states lie away from the band edges system goes to transparent state. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Two-photon exclusive processes in quantum chromodynamics

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1986-07-01

    QCD predictions for γγ annihilation into single mesons, meson pairs, and baryon pairs are reviewed. Two-photon exclusive processes provide the most sensitive and practical measure of the distribution amplitudes, and thus a critical confrontation between QCD and experiment. Both the angular distribution and virtual photon mass dependence of these amplitudes are sensitive to the shapes of the phi (chi, Q). Novel effects involving the production of qq anti q anti q states at threshold are also discussed, and a new method is presented for systematically incorporating higher-order QCD corrections in γγ reactions

  6. Two-photon exclusive processes in quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1986-07-01

    QCD predictions for ..gamma gamma.. annihilation into single mesons, meson pairs, and baryon pairs are reviewed. Two-photon exclusive processes provide the most sensitive and practical measure of the distribution amplitudes, and thus a critical confrontation between QCD and experiment. Both the angular distribution and virtual photon mass dependence of these amplitudes are sensitive to the shapes of the phi (chi, Q). Novel effects involving the production of qq anti q anti q states at threshold are also discussed, and a new method is presented for systematically incorporating higher-order QCD corrections in ..gamma gamma.. reactions.

  7. Relativistic Photon Induced Processes of Composite Particles

    International Nuclear Information System (INIS)

    Ribeiro-Silva, C.I; Curado, E. M. F.; Rego-Monteiro, M. A.

    2007-01-01

    We consider a complex quantum field theory based on a generalized Heisenberg[1] algebra, which describes at the space-time a spin less composite particle. We compute the perturbative series and the cross section of the scattering process 2 γ→φ - , φ + up to second order in the coupling constant and we find a further contribution due to the structure of the composite pion which is described here phenomenologically by the generalized algebra. We compare the results of this study with available experimental data. (Author)

  8. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying the technology instrumentation of photonics This volume discusses photonics technology and instrumentation. The topics discussed in this volume are: Communication Networks; Data Buffers; Defense and Security Applications; Detectors; Fiber Optics and Amplifiers; Green Photonics; Instrumentation and Metrology; Interferometers; Light-Harvesting Materials; Logic Devices; Optical Communications; Remote Sensing; Solar Energy; Solid-State Lighting; Wavelength Conversion Comprehensive and accessible coverage of the whole of modern photonics Emphas

  9. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying thescience and technology of nanophotonics, its materials andstructures This volume presents nanophotonic structures and Materials.Nanophotonics is photonic science and technology that utilizeslight/matter interactions on the nanoscale where researchers arediscovering new phenomena and developing techniques that go wellbeyond what is possible with conventional photonics andelectronics.The topics discussed in this volume are: CavityPhotonics; Cold Atoms and Bose-Einstein Condensates; Displays;E-paper; Graphene; Integrated Photonics; Liquid Cry

  10. Monte Carlo simulation of two-photon processes

    International Nuclear Information System (INIS)

    Daverveldt, P.H.W.M.

    1985-01-01

    During the last two decades e + e - collider experiments provided physicists with a wealth of important discoveries concerning elementary particle physics. This thesis explains in detail how the Monte Carlo approach can be applied to establish the comparison between two-photon experiments and theory. The author describes the main motives for and objectives of two-photon research. He defines the kinematics and pays attention to some special kinematical regions. Also a popular approximation for the exact differential cross section is reviewed. Next he discusses the calculation of the complete lowest order cross section for processes with four leptons in the final state and for reactions such as e + e - →e + e - qanti q, e + e - →μ + μ - qanti q. Radiative corrections to the multiperipheral diagrams are considered. The author explains in detail the distinction between soft and hard photon corrections which turns out to be somewhat more tricky than in the case of radiative corrections to one-photon processes. Finally, he presents some results which were obtained by using the event generators. (Auth.)

  11. Single photon laser altimeter simulator and statistical signal processing

    Science.gov (United States)

    Vacek, Michael; Prochazka, Ivan

    2013-05-01

    Spaceborne altimeters are common instruments onboard the deep space rendezvous spacecrafts. They provide range and topographic measurements critical in spacecraft navigation. Simultaneously, the receiver part may be utilized for Earth-to-satellite link, one way time transfer, and precise optical radiometry. The main advantage of single photon counting approach is the ability of processing signals with very low signal-to-noise ratio eliminating the need of large telescopes and high power laser source. Extremely small, rugged and compact microchip lasers can be employed. The major limiting factor, on the other hand, is the acquisition time needed to gather sufficient volume of data in repetitive measurements in order to process and evaluate the data appropriately. Statistical signal processing is adopted to detect signals with average strength much lower than one photon per measurement. A comprehensive simulator design and range signal processing algorithm are presented to identify a mission specific altimeter configuration. Typical mission scenarios (celestial body surface landing and topographical mapping) are simulated and evaluated. The high interest and promising single photon altimeter applications are low-orbit (˜10 km) and low-radial velocity (several m/s) topographical mapping (asteroids, Phobos and Deimos) and landing altimetry (˜10 km) where range evaluation repetition rates of ˜100 Hz and 0.1 m precision may be achieved. Moon landing and asteroid Itokawa topographical mapping scenario simulations are discussed in more detail.

  12. Induction linear accelerators for commercial photon irradiation processing

    International Nuclear Information System (INIS)

    Matthews, S.M.

    1989-01-01

    A number of proposed irradiation processes requires bulk rather than surface exposure with intense applications of ionizing radiation. Typical examples are irradiation of food packaged into pallet size containers, processing of sewer sludge for recycling as landfill and fertilizer, sterilization of prepackaged medical disposals, treatment of municipal water supplies for pathogen reduction, etc. Volumetric processing of dense, bulky products with ionizing radiation requires high energy photon sources because electrons are not penetrating enough to provide uniform bulk dose deposition in thick, dense samples. Induction Linear Accelerator (ILA) technology developed at the Lawrence Livermore National Laboratory promises to play a key role in providing solutions to this problem. This is discussed in this paper

  13. Simulation of neutron transport process, photons and charged particles within the Monte Carlo method

    International Nuclear Information System (INIS)

    Androsenko, A.A.; Androsenko, P.A.; Artamonov, S.N.; Bolonkina, G.V.; Lomtev, V.L.; Pupko, S.V.

    1991-01-01

    Description is given to the program system BRAND designed for the accurate solution of non-stationary transport equation of neutrons, photons and charged particles in the conditions of real three-dimensional geometry. An extensive set of local and non-local estimates provides an opportunity of calculating a great set of linear functionals normally being of interest in the calculation of reactors, radiation protection and experiment simulation. The process of particle interaction with substance is simulated on the basis of individual non-group data on each isotope of the composition. 24 refs

  14. Photonic Architecture for Scalable Quantum Information Processing in Diamond

    Directory of Open Access Journals (Sweden)

    Kae Nemoto

    2014-08-01

    Full Text Available Physics and information are intimately connected, and the ultimate information processing devices will be those that harness the principles of quantum mechanics. Many physical systems have been identified as candidates for quantum information processing, but none of them are immune from errors. The challenge remains to find a path from the experiments of today to a reliable and scalable quantum computer. Here, we develop an architecture based on a simple module comprising an optical cavity containing a single negatively charged nitrogen vacancy center in diamond. Modules are connected by photons propagating in a fiber-optical network and collectively used to generate a topological cluster state, a robust substrate for quantum information processing. In principle, all processes in the architecture can be deterministic, but current limitations lead to processes that are probabilistic but heralded. We find that the architecture enables large-scale quantum information processing with existing technology.

  15. Determining the quark charges by one and two photon processes

    International Nuclear Information System (INIS)

    Janah, A.

    1982-01-01

    Testable predictions are presented, which may be used to decide between the gauge theories of integer and fractionally charged quarks (icq and fcq). Two distinctive features of icq are exploited, namely (a) presence of color non-singlet components in weak and electromagnetic currents and (b) possible liberation of color non-singlet states above a threshold energy. Consequences are sought in lepton-hadron interaction processes, taking into account the known color-suppression effect. Single photon/weak-boson processes such as nuN → nuX distinguish between icq and fcq only above color-threshold. Experimental consequences of color-liberation in the above process are obtained. It is found that the gluon-parton contribution survives color-suppression to produce a significant rise in the structure functions when color-threshold is exceeded. Two-photon processes such as e + e - → e + e - + 2 jets distinguish between the two theories even below color threshold. To obtain the icq predictions for this process, one must take into account (a) the (momentum-dependent) color suppression and (b) the added contribution from pair production of charged gluons

  16. Opportunities and challenges for process control in process intensification

    NARCIS (Netherlands)

    Nikacevic, N.M.; Huesman, A.E.M.; Hof, Van den P.M.J.; Stankiewicz, A.

    2012-01-01

    This is a review and position article discussing the role and prospective for process control in process intensification. Firstly, the article outlines the classical role of control in process systems, presenting an overview of control systems’ development, from basic PID control to the advanced

  17. Food Processing and Marketing: New Directions...New Opportunities.

    Science.gov (United States)

    Welch, Mary A., Ed.

    1995-01-01

    This issue uses tomato processing to illustrate the new directions and opportunities available in the food market. Comparative advantage and economies of scale are discussed in relation to markets. Forecasting success in the market is attributed to studying consumer consumption trends by type and monitoring standards of living in 32 newly…

  18. Direct and indirect two-photon processes in semiconductors

    International Nuclear Information System (INIS)

    Hassan, A.R.

    1986-07-01

    The expressions describing direct and indirect two-photon absorption in crystals are given. They are valid both near and far from the energy gap. A perturbative approach through two different band models is adopted. The effects of the non-parabolicity and the degeneracy of the energy bands are considered. The numerical results are compared with the other theories and with a recent experimental data in Zn and AgCl. It is shown that the dominant transition mechanisms are of the allowed-allowed type near and far from the gap for both direct and indirect processes. (author)

  19. Development of a multitechnology FPGA: a reconfigurable architecture for photonic information processing

    Science.gov (United States)

    Mal, Prosenjit; Toshniwal, Kavita; Hawk, Chris; Bhadri, Prashant R.; Beyette, Fred R., Jr.

    2004-06-01

    Over the years, Field Programmable Gate Arrays (FPGAs) have made a profound impact on the electronics industry with rapidly improving semiconductor-manufacturing technology ranging from sub-micron to deep sub-micron processes and equally innovative CAD tools. Though FPGA has revolutionized programmable/reconfigurable digital logic technology, one limitation of current FPGA"s is that the user is limited to strictly electronic designs. Thus, they are not suitable for applications that are not purely electronic, such as optical communications, photonic information processing systems and other multi-technology applications (ex. analog devices, MEMS devices and microwave components). Over recent years, the growing trend has been towards the incorporation of non-traditional device technologies into traditional CMOS VLSI systems. The integration of these technologies requires a new kind of FPGA that can merge conventional FPGA technology with photonic and other multi-technology devices. The proposed new class of field programmable device will extend the flexibility, rapid prototyping and reusability benefits associated with conventional electronic into photonic and multi-technology domain and give rise to the development of a wider class of programmable and embedded integrated systems. This new technology will create a tremendous opportunity for applying the conventional programmable/reconfigurable hardware concepts in other disciplines like photonic information processing. To substantiate this novel architectural concept, we have fabricated proof-of-the-concept CMOS VLSI Multi-technology FPGA (MT-FPGA) chips that include both digital field programmable logic blocks and threshold programmable photoreceivers which are suitable for sensing optical signals. Results from these chips strongly support the feasibility of this new optoelectronic device concept.

  20. Processing Challenges and Opportunities of Camel Dairy Products

    DEFF Research Database (Denmark)

    Berhe, Tesfemariam; Seifu, Eyassu; Ipsen, Richard

    2017-01-01

    A review on the challenges and opportunities of processing camel milk into dairy products is provided with an objective of exploring the challenges of processing and assessing the opportunities for developing functional products from camel milk. The gross composition of camel milk is similar...... to bovine milk. Nonetheless, the relative composition, distribution, and the molecular structure of the milk components are reported to be different. Consequently, manufacturing of camel dairy products such as cheese, yoghurt, or butter using the same technology as for dairy products from bovine milk can...... result in processing difficulties and products of inferior quality. However, scientific evidence points to the possibility of transforming camel milk into products by optimization of the processing parameters. Additionally, camel milk has traditionally been used for its medicinal values and recent...

  1. Blockchains for Business Process Management - Challenges and Opportunities

    OpenAIRE

    Mendling, Jan; Weber, Ingo; van der Aalst, Wil; Brocke, Jan vom; Cabanillas, Cristina; Daniel, Florian; Debois, Soren; Di Ciccio, Claudio; Dumas, Marlon; Dustdar, Schahram; Gal, Avigdor; Garcia-Banuelos, Luciano; Governatori, Guido; Hull, Richard; La Rosa, Marcello

    2017-01-01

    Blockchain technology offers a sizable promise to rethink the way inter-organizational business processes are managed because of its potential to realize execution without a central party serving as a single point of trust (and failure). To stimulate research on this promise and the limits thereof, in this paper we outline the challenges and opportunities of blockchain for Business Process Management (BPM). We first reflect how blockchains could be used in the context of the established BPM l...

  2. Consistency check of photon beam physical data after recommissioning process

    International Nuclear Information System (INIS)

    Kadman, B; Chawapun, N; Ua-apisitwong, S; Asakit, T; Chumpu, N; Rueansri, J

    2016-01-01

    In radiotherapy, medical linear accelerator (Linac) is the key system used for radiation treatments delivery. Although, recommissioning was recommended after major modification of the machine by AAPM TG53, but it might not be practical in radiotherapy center with heavy workloads. The main purpose of this study was to compare photon beam physical data between initial commissioning and recommissioning of 6 MV Elekta Precise linac. The parameters for comparing were the percentage depth dose (PDD) and beam profiles. The clinical commissioning test cases followed IAEA-TECDOC-1583 were planned on REF 91230 IMRT Dose Verification Phantom by Philips’ Pinnacle treatment planning system. The Delta 4PT was used for dose distribution verification with 90% passing criteria of the gamma index (3%/3mm). Our results revealed that the PDDs and beam profiles agreed within a tolerance limit recommended by TRS430. Most of the point doses and dose distribution verification passed the acceptance criteria. This study showed the consistency of photon beam physical data after recommissioning process. There was a good agreement between initial commissioning and recommissioning within a tolerance limit, demonstrated that the full recommissioning process might not be required. However, in the complex treatment planning geometry, the initial data should be applied with great caution. (paper)

  3. Optics and photonics education centers of excellence: an opportunity for international collaboration

    Science.gov (United States)

    Hull, Daniel M.

    2015-10-01

    The increased demand for highly educated and trained workers in optics and photonics is evident in many countries. Colleges and universities that provide this education can benefit greatly from support by non-profit National Education Centers of Excellence that conduct research in workforce needs, design curricula, develop industry-validated teaching materials, train new faculty and establish models for laser/optics laboratories. In 2006, the National Science Foundation (NSF) established OP-TEC, the National Center for Optics and Photonics Education, which encourages and supports U.S. colleges to educate and train an adequate supply of high quality technicians to meet the workforce demand by companies, institutions and government agencies. In 2013 and 2014 NSF awarded grants to establish regional photonics centers in the southeast U.S. (LASER-TEC) and the Midwest (MPEC). These Centers work cooperatively with OP-TEC, sharing resources, teaching materials and best practices for colleges with photonics technician education programs. This successful "center organization plan" that has evolved could be adopted in other countries, and international cooperation could be established between similar Centers of Education in Photonics education.

  4. Scalable quantum information processing with photons and atoms

    Science.gov (United States)

    Pan, Jian-Wei

    Over the past three decades, the promises of super-fast quantum computing and secure quantum cryptography have spurred a world-wide interest in quantum information, generating fascinating quantum technologies for coherent manipulation of individual quantum systems. However, the distance of fiber-based quantum communications is limited due to intrinsic fiber loss and decreasing of entanglement quality. Moreover, probabilistic single-photon source and entanglement source demand exponentially increased overheads for scalable quantum information processing. To overcome these problems, we are taking two paths in parallel: quantum repeaters and through satellite. We used the decoy-state QKD protocol to close the loophole of imperfect photon source, and used the measurement-device-independent QKD protocol to close the loophole of imperfect photon detectors--two main loopholes in quantum cryptograph. Based on these techniques, we are now building world's biggest quantum secure communication backbone, from Beijing to Shanghai, with a distance exceeding 2000 km. Meanwhile, we are developing practically useful quantum repeaters that combine entanglement swapping, entanglement purification, and quantum memory for the ultra-long distance quantum communication. The second line is satellite-based global quantum communication, taking advantage of the negligible photon loss and decoherence in the atmosphere. We realized teleportation and entanglement distribution over 100 km, and later on a rapidly moving platform. We are also making efforts toward the generation of multiphoton entanglement and its use in teleportation of multiple properties of a single quantum particle, topological error correction, quantum algorithms for solving systems of linear equations and machine learning. Finally, I will talk about our recent experiments on quantum simulations on ultracold atoms. On the one hand, by applying an optical Raman lattice technique, we realized a two-dimensional spin-obit (SO

  5. DNA-templated photonic arrays and assemblies: design principles and future opportunities.

    Science.gov (United States)

    Su, Wu; Bonnard, Vanessa; Burley, Glenn A

    2011-07-11

    Molecular photonics is a rapidly developing and multi-disciplinary field of research involving the construction of molecular assemblies comprising photoactive building blocks that are responsive to a light stimulus. A salient challenge in this field is the controlled assembly of these building blocks with nanoscale precision. DNA exhibits considerable promise as an architecture for the templated assembly of photoactive materials. In this Concept Article we describe the progress that has been made in the area of DNA photonics, in which DNA acts as a platform for the construction of optoelectronic assemblies, thin films and devices. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Scalable quantum information processing with atomic ensembles and flying photons

    International Nuclear Information System (INIS)

    Mei Feng; Yu Yafei; Feng Mang; Zhang Zhiming

    2009-01-01

    We present a scheme for scalable quantum information processing with atomic ensembles and flying photons. Using the Rydberg blockade, we encode the qubits in the collective atomic states, which could be manipulated fast and easily due to the enhanced interaction in comparison to the single-atom case. We demonstrate that our proposed gating could be applied to generation of two-dimensional cluster states for measurement-based quantum computation. Moreover, the atomic ensembles also function as quantum repeaters useful for long-distance quantum state transfer. We show the possibility of our scheme to work in bad cavity or in weak coupling regime, which could much relax the experimental requirement. The efficient coherent operations on the ensemble qubits enable our scheme to be switchable between quantum computation and quantum communication using atomic ensembles.

  7. Two-photon resonant, stimulated processes in krypton and xenon

    International Nuclear Information System (INIS)

    Miller, J.C.

    1988-11-01

    Both on-axis and conical emissions have been observed following two-photon pumping of the 5p states of krypton and the 6p', 7p, 8p, and 4f states of xenon. In the former case, coherent emissions from the 5p states to the 5s are observed, and in the latter case, many p→s, d→p, and f→d cascade emissions are observed. By analogy to the well-studied alkali and alkaline earth examples, the emissions are discussed in terms of amplified spontaneous emission (ASE), stimulated hyper-Raman scattering, and parametric four-wave mixing. The physical processes responsible for the conical emission and for intensity anomalies in the xenon p→s emissions are not understood at present. Interference effects due to coherent cancellation between competing excitation pathways may be occurring. 4 refs., 3 figs

  8. Blockchains for Business Process Management - Challenges and Opportunities

    DEFF Research Database (Denmark)

    Mendling, Jan; Weber, Ingo; Van Der Aalst, Wil

    2018-01-01

    Blockchain technology offers a sizable promise to rethink the way inter-organizational business processes are managed because of its potential to realize execution without a central party serving as a single point of trust (and failure). To stimulate research on this promise and the limits thereof......, in this paper we outline the challenges and opportunities of blockchain for Business Process Management (BPM). We first reflect how blockchains could be used in the context of the established BPM lifecycle and second how they might become relevant beyond. We conclude our discourse with a summary of seven...... research directions for investigating the application of blockchain technology in the context of BPM...

  9. Microgravity Processing and Photonic Applications of Organic and Polymeric Materials

    Science.gov (United States)

    Frazier, Donald 0; Penn, Benjamin G.; Smith, David; Witherow, William K.; Paley, M. S.; Abdeldayem, Hossin A.

    1998-01-01

    In recent years, a great deal of interest has been directed toward the use of organic materials in the development of high-efficiency optoelectronic and photonic devices. There is a myriad of possibilities among organic which allow flexibility in the design of unique structures with a variety of functional groups. The use of nonlinear optical (NLO) organic materials such as thin-film waveguides allows full exploitation of their desirable qualities by permitting long interaction lengths and large susceptibilities allowing modest power input. There are several methods in use to prepare thin films, such as Langmuir-Blodgett (LB) and self-assembly techniques, vapor deposition, growth from sheared solution or melt, and melt growth between glass plates. Organics have many features that make Abstract: them desirable for use in optical devices such as high second- and third-order nonlinearities, flexibility of molecular design, and damage resistance to optical radiation. However, their use in devices has been hindered by processing difficulties for crystals and thin films. In this chapter, we discuss photonic and optoelectronic applications of a few organic materials and the potential role of microgravity on processing these materials. It is of interest to note how materials with second- and third-order nonlinear optical behavior may be improved in a diffusion-limited environment and ways in which convection may be detrimental to these materials. We focus our discussion on third-order materials for all-optical switching, and second-order materials for all-optical switching, and second-order materials for frequency conversion and electrooptics.

  10. Advanced Photonic Processes for Photovoltaic and Energy Storage Systems.

    Science.gov (United States)

    Sygletou, Maria; Petridis, Constantinos; Kymakis, Emmanuel; Stratakis, Emmanuel

    2017-10-01

    Solar-energy harvesting through photovoltaic (PV) conversion is the most promising technology for long-term renewable energy production. At the same time, significant progress has been made in the development of energy-storage (ES) systems, which are essential components within the cycle of energy generation, transmission, and usage. Toward commercial applications, the enhancement of the performance and competitiveness of PV and ES systems requires the adoption of precise, but simple and low-cost manufacturing solutions, compatible with large-scale and high-throughput production lines. Photonic processes enable cost-efficient, noncontact, highly precise, and selective engineering of materials via photothermal, photochemical, or photophysical routes. Laser-based processes, in particular, provide access to a plethora of processing parameters that can be tuned with a remarkably high degree of precision to enable innovative processing routes that cannot be attained by conventional approaches. The focus here is on the application of advanced light-driven approaches for the fabrication, as well as the synthesis, of materials and components relevant to PV and ES systems. Besides presenting recent advances on recent achievements, the existing limitations are outlined and future possibilities and emerging prospects discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Processing Challenges and Opportunities of Camel Dairy Products

    Directory of Open Access Journals (Sweden)

    Tesfemariam Berhe

    2017-01-01

    Full Text Available A review on the challenges and opportunities of processing camel milk into dairy products is provided with an objective of exploring the challenges of processing and assessing the opportunities for developing functional products from camel milk. The gross composition of camel milk is similar to bovine milk. Nonetheless, the relative composition, distribution, and the molecular structure of the milk components are reported to be different. Consequently, manufacturing of camel dairy products such as cheese, yoghurt, or butter using the same technology as for dairy products from bovine milk can result in processing difficulties and products of inferior quality. However, scientific evidence points to the possibility of transforming camel milk into products by optimization of the processing parameters. Additionally, camel milk has traditionally been used for its medicinal values and recent scientific studies confirm that it is a rich source of bioactive, antimicrobial, and antioxidant substances. The current literature concerning product design and functional potential of camel milk is fragmented in terms of time, place, and depth of the research. Therefore, it is essential to understand the fundamental features of camel milk and initiate detailed multidisciplinary research to fully explore and utilize its functional and technological properties.

  12. Exotic Optical Fibers and Glasses: Innovative Material Processing Opportunities in Earth's Orbit.

    Science.gov (United States)

    Cozmuta, Ioana; Rasky, Daniel J

    2017-09-01

    Exotic optical fibers and glasses are the platform material for photonics applications, primarily due to their superior signal transmission (speed, low attenuation), with extending bandwidth deep into the infrared, exceeding that of silica fibers. Gravitational effects (convection sedimentation) have a direct impact on the phase diagram of these materials and influence melting properties, crystallization temperatures, and viscosity of the elemental mix during the manufacturing process. Such factors constitute limits to the yield, transmission quality, and strength and value of these fibers; they also constrain the range of applications. Manufacturing in a gravity-free environment such as the Earth's Orbit also helps with other aspects of the fabrication process (i.e., improved form factor of the manufacturing unit, sustainability). In this article, revolutionary developments in the field of photonics over the past decade merge with the paradigm shift in the privatization of government-owned capabilities supporting a more diverse infrastructure (parabolic, suborbital, orbital), reduced price, and increased frequency to access space and the microgravity environment. With the increased dependence on data (demand, bandwidth, efficiency), space and the microgravity environment provide opportunities for optimized performance of these exotic optical fibers and glasses underlying the development of enabling technologies to meet future data demand. Existing terrestrial markets (Internet, telecommunications, market transactions) and emerging space markets (on-orbit satellite servicing, space manufacturing, space resources, space communications, etc.) seem to converge, and this innovative material processing opportunity of exotic optical fibers and glasses might just be that "killer app": technologically competitive, economically viable, and with the ability to close the business case.

  13. Experimental review of exclusive processes in two photon reactions

    International Nuclear Information System (INIS)

    Ronan, M.T.

    1986-07-01

    Recent experimental results on exclusive final stated produced in photon-photon interactions are reviewed. Comparisons between experiments and with perturbative QCD calculations are made for meson and baryon pair production. New results on vector meson pair (rho 0 rho 0 ,rho 0 omega,rho 0 phi,...) production and production of multiparticle (KKππ,K*Kπ,...) final states are summarized. 34 refs

  14. Microscale technology and biocatalytic processes: opportunities and challenges for synthesis.

    Science.gov (United States)

    Wohlgemuth, Roland; Plazl, Igor; Žnidaršič-Plazl, Polona; Gernaey, Krist V; Woodley, John M

    2015-05-01

    Despite the expanding presence of microscale technology in chemical synthesis and energy production as well as in biomedical devices and analytical and diagnostic tools, its potential in biocatalytic processes for pharmaceutical and fine chemicals, as well as related industries, has not yet been fully exploited. The aim of this review is to shed light on the strategic advantages of this promising technology for the development and realization of biocatalytic processes and subsequent product recovery steps, demonstrated with examples from the literature. Constraints, opportunities, and the future outlook for the implementation of these key green engineering methods and the role of supporting tools such as mathematical models to establish sustainable production processes are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Microscopic theory of cavity-enhanced single-photon emission from optical two-photon Raman processes

    Science.gov (United States)

    Breddermann, Dominik; Praschan, Tom; Heinze, Dirk; Binder, Rolf; Schumacher, Stefan

    2018-03-01

    We consider cavity-enhanced single-photon generation from stimulated two-photon Raman processes in three-level systems. We compare four fundamental system configurations, one Λ -, one V-, and two ladder (Ξ -) configurations. These can be realized as subsystems of a single quantum dot or of quantum-dot molecules. For a new microscopic understanding of the Raman process, we analyze the Heisenberg equation of motion applying the cluster-expansion scheme. Within this formalism an exact and rigorous definition of a cavity-enhanced Raman photon via its corresponding Raman correlation is possible. This definition for example enables us to systematically investigate the on-demand potential of Raman-transition-based single-photon sources. The four system arrangements can be divided into two subclasses, Λ -type and V-type, which exhibit strongly different Raman-emission characteristics and Raman-emission probabilities. Moreover, our approach reveals whether the Raman path generates a single photon or just induces destructive quantum interference with other excitation paths. Based on our findings and as a first application, we gain a more detailed understanding of experimental data from the literature. Our analysis and results are also transferable to the case of atomic three-level-resonator systems and can be extended to more complicated multilevel schemes.

  16. Photonic sensor opportunities for distributed and wireless systems in security applications

    Science.gov (United States)

    Krohn, David

    2006-10-01

    There are broad ranges of homeland security sensing applications that can be facilitated by distributed fiber optic sensors and photonics integrated wireless systems. These applications include [1]: Pipeline, (Monitoring, Security); Smart structures (Bridges, Tunnels, Dams, Public spaces); Power lines (Monitoring, Security); Transportation security; Chemical/biological detection; Wide area surveillance - perimeter; and Port Security (Underwater surveillance, Cargo container). Many vital assets which cover wide areas, such as pipeline and borders, are under constant threat of being attacked or breached. There is a rapidly emerging need to be able to provide identification of intrusion threats to such vital assets. Similar problems exit for monitoring the basic infrastructure such as water supply, power utilities, communications systems as well as transportation. There is a need to develop a coordinated and integrated solution for the detection of threats. From a sensor standpoint, consideration must not be limited to detection, but how does detection lead to intervention and deterrence. Fiber optic sensor technology must be compatible with other surveillance technologies such as wireless mote technology to facilitate integration. In addition, the multi-functionality of fiber optic sensors must be expanded to include bio-chemical detection. There have been a number of barriers for the acceptance and broad use of smart fiber optic sensors. Compared to telecommunications, the volume is low. This fact coupled with proprietary and custom specifications has kept the price of fiber optic sensors high. There is a general lack of a manufacturing infrastructure and lack of standards for packaging and reliability. Also, there are several competing technologies; some photonic based and other approaches based on conventional non-photonic technologies.

  17. The MARS Photon Processing Cameras for Spectral CT

    CERN Document Server

    Doesburg, Robert Michael Nicholas; Butler, APH; Renaud, PF

    This thesis is about the development of the MARS camera: a stan- dalone portable digital x-ray camera with spectral sensitivity. It is built for use in the MARS Spectral system from the Medipix2 and Medipix3 imaging chips. Photon counting detectors and Spectral CT are introduced, and Medipix is identified as a powerful new imaging device. The goals and strategy for the MARS camera are discussed. The Medipix chip physical, electronic and functional aspects, and ex- perience gained, are described. The camera hardware, firmware and supporting PC software are presented. Reports of experimental work on the process of equalisation from noise, and of tests of charge sum- ming mode, conclude the main body of the thesis. The camera has been actively used since late 2009 in pre-clinical re- search. A list of publications that derive from the use of the camera and the MARS Spectral scanner demonstrates the practical benefits already obtained from this work. Two of the publications are first- author, eight are co-authore...

  18. Agreements process: problems and opportunities for the states

    International Nuclear Information System (INIS)

    Hunter, T.

    1985-01-01

    The Nuclear Waste Policy Act of 1982 (the Act) directs the Secretary of the US Department of Energy (US DOE) to consult and cooperate with the Governor and legislature of each state within which a candidate site for a nuclear waste repository may exist. The Act further directs USDOE to begin negotiations and to seek to enter into a binding written agreement to address specific concerns of any candidate state which requests such an agreement or within which a site has been approved for site characterization. The written agreements are to address at least the eleven topic areas specified in the Act and are to be completed within six months if possible. The author has been a negotiator for the State of Washington in the repository siting agreements process over the past year. The experience of the author has shown that the agreements process as contemplated by the Act bears little resemblance to the institutional interaction process of the state and federal government on matters relating to consideration of the state for a nuclear waste repository. This paper seeks to analyze the agreements process as it has developed in one state, and identify the problems and opportunities in that process so that other states and USDOE may learn from that experience

  19. Photon Production through Multi-step Processes Important in Nuclear Fluorescence Experiments

    International Nuclear Information System (INIS)

    Hagmann, C; Pruet, J

    2006-01-01

    The authors present calculations describing the production of photons through multi-step processes occurring when a beam of gamma rays interacts with a macroscopic material. These processes involve the creation of energetic electrons through Compton scattering, photo-absorption and pair production, the subsequent scattering of these electrons, and the creation of energetic photons occurring as these electrons are slowed through Bremsstrahlung emission. Unlike single Compton collisions, during which an energetic photon that is scattered through a large angle loses most of its energy, these multi-step processes result in a sizable flux of energetic photons traveling at large angles relative to an incident photon beam. These multi-step processes are also a key background in experiments that measure nuclear resonance fluorescence by shining photons on a thin foil and observing the spectrum of back-scattered photons. Effective cross sections describing the production of backscattered photons are presented in a tabular form that allows simple estimates of backgrounds expected in a variety of experiments. Incident photons with energies between 0.5 MeV and 8 MeV are considered. These calculations of effective cross sections may be useful for those designing NRF experiments or systems that detect specific isotopes in well-shielded environments through observation of resonance fluorescence

  20. Vector meson dominance and pointlike coupling of the photon in soft and hard processes

    International Nuclear Information System (INIS)

    Paul, E.

    1990-05-01

    Recent experimental results on photoproduction of hadrons probe the nature of the interacting photon over a wide kinematical range from soft to hard processes. Single inclusive spectra and energy flows of the final state charged particles are well described by assuming that photon production data are built up by an incoherent superposition of a soft Vector-Meson-Dominance component and a hard pointlike photon component. (orig.)

  1. Patient level costing in Ireland: process, challenges and opportunities.

    Science.gov (United States)

    Murphy, A; McElroy, B

    2015-03-01

    In 2013, the Department of Health released their policy paper on hospital financing entitled Money Follows the Patient. A fundamental building block for the proposed financing model is patient level costing. This paper outlines the patient level costing process, identifies the opportunities and considers the challenges associated with the process in the Irish hospital setting. Methods involved a review of the existing literature which was complemented with an interview with health service staff. There are considerable challenges associated with implementing patient level costing including deficits in information and communication technologies and financial expertise as well as timeliness of coding. In addition, greater clinical input into the costing process is needed compared to traditional costing processes. However, there are long-term benefits associated with patient level costing; these include empowerment of clinical staff, improved transparency and price setting and greater fairness, especially in the treatment of outliers. These can help to achieve the Government's Health Strategy. The benefits of patient level costing need to be promoted and a commitment to investment in overcoming the challenges is required.

  2. The process of developing audiovisual patient information: challenges and opportunities.

    Science.gov (United States)

    Hutchison, Catherine; McCreaddie, May

    2007-11-01

    The aim of this project was to produce audiovisual patient information, which was user friendly and fit for purpose. The purpose of the audiovisual patient information is to inform patients about randomized controlled trials, as a supplement to their trial-specific written information sheet. Audiovisual patient information is known to be an effective way of informing patients about treatment. User involvement is also recognized as being important in the development of service provision. The aim of this paper is (i) to describe and discuss the process of developing the audiovisual patient information and (ii) to highlight the challenges and opportunities, thereby identifying implications for practice. A future study will test the effectiveness of the audiovisual patient information in the cancer clinical trial setting. An advisory group was set up to oversee the project and provide guidance in relation to information content, level and delivery. An expert panel of two patients provided additional guidance and a dedicated operational team dealt with the logistics of the project including: ethics; finance; scriptwriting; filming; editing and intellectual property rights. Challenges included the limitations of filming in a busy clinical environment, restricted technical and financial resources, ethical needs and issues around copyright. There were, however, substantial opportunities that included utilizing creative skills, meaningfully involving patients, teamworking and mutual appreciation of clinical, multidisciplinary and technical expertise. Developing audiovisual patient information is an important area for nurses to be involved with. However, this must be performed within the context of the multiprofessional team. Teamworking, including patient involvement, is crucial as a wide variety of expertise is required. Many aspects of the process are transferable and will provide information and guidance for nurses, regardless of specialty, considering developing this

  3. Challenges and opportunities for plasma processing of materials

    International Nuclear Information System (INIS)

    McKenzie, D.R.

    1999-01-01

    Full text: Plasma processing of materials is in many ways at a turning point in its development. On the one hand, there are new opportunities arising from the environmental concerns associated with conventional materials processing methods such as electroplating. On the other hand, there are challenges associated with the large capital cost of plant and the demonstration that the new techniques can deliver the quality and quantity required in the market place. An example of such a challenge is file replacement of electroplated chromium by sputtered alternatives in the solar absorber coatings industry. Cathodic arc based processes also offer opportunities for advanced materials processing to displace electroplating. The use of cathodic arcs to coat gold look-alike finishes for architectural applications is well advanced. The challenges for other coatings are essentially dependent on the quality of the adhesion. The combination of the cathodic arc with Plasma Immersion Ion implantation (PI 3 ) technology gives significant improvements in film adhesion. The energy of the incident ions from the cathodic arc may be readily increased to 20 KeV or so without serious difficulties. We have been carrying out trials of a PI 3 type power supply developed by ANSTO, coupled to a continuous type cathodic arc fitted with a magnetic sector filter. The power supply provides short pulses with an adjustable repetition rate and duty cycle. The pulses provide bursts of energetic ions which can be used for assisting the deposition of coatings or for implantation without coating, depending on the location and orientation of the substrate. The results for film adhesion are promising on a number of substrates. The adhesion of metal films on polyimide substrates for example is definitely improved. The modification of polymers to improve their scratch resistance is becoming an important opportunity for plasma processing. Polymers have some valuable properties such as strength to weight ratio

  4. Scientific Opportunities to Reduce Risk in Nuclear Process Science

    International Nuclear Information System (INIS)

    Bredt, Paul R.; Felmy, Andrew R.; Gauglitz, Phillip A.; Hobbs, David T.; Krahn, Steve; Machara, N.; Mcilwain, Michael; Moyer, Bruce A.; Poloski, Adam P.; Subramanian, K.; Vienna, John D.; Wilmarth, B.

    2008-01-01

    Cleaning up the nation's nuclear weapons complex remains as one of the most technologically challenging and financially costly problems facing the U.S. Department of Energy (DOE). Safety, cost, and technological challenges have often delayed progress in retrieval, processing, and final disposition of high-level waste, spent nuclear fuel, and challenging materials. Some of the issues result from the difficulty and complexity of the technological issues; others have programmatic bases, such as contracting strategies that may provide undue focus on near-term, specific clean-up goals or difficulty in developing and maintaining stakeholder confidence in the proposed solutions. We propose that independent basic fundamental science research focused on the full cleanup life-cycle offers an opportunity to help address these challenges by providing (1) scientific insight into the fundamental mechanisms involved in currently selected processing and disposal options, (2) a rational path to the development of alternative technologies should the primary options fail, (3) confidence that models that predict long-term performance of different disposal options are based upon the best available science, (4) fundamental science discovery that enables transformational solutions to revolutionize the current baseline processes.

  5. Scientific Opportunities to Reduce Risk in Nuclear Process Science

    International Nuclear Information System (INIS)

    Bredt, Paul R.; Felmy, Andrew R.; Gauglitz, Phillip A.; Poloski, Adam P.; Vienna, John D.; Moyer, Bruce A.; Hobbs, David; Wilmarth, B.; Mcilwain, Michael; Subramanian, K.; Krahn, Steve; Machara, N.

    2009-01-01

    Cleaning up the nation's nuclear weapons complex remains as one of the most technologically challenging and financially costly problems facing the U.S. Department of Energy (DOE). Safety, cost, and technological challenges have often delayed progress in retrieval, processing, and final disposition of high-level waste, spent nuclear fuel, and challenging materials. Some of the issues result from the difficulty and complexity of the technological issues; others have programmatic bases, such as strategies that may provide undue focus on near-term goals or difficulty in developing and maintaining stakeholder confidence in the proposed solutions. We propose that independent basic fundamental science research, addressing the full cleanup life-cycle, offers an opportunity to help address these challenges by providing (1) scientific insight into the fundamental mechanisms involved in currently selected processing and disposal options, (2) a rational path to the development of alternative technologies should the primary options fail, (3) confidence that models that predict long-term performance of different disposal options are based upon the best available science, and (4) fundamental science discovery that enables transformational solutions to revolutionize the current baseline processes. Over the last 3 years, DOE's Office of Environmental Management (EM) has experienced a fundamental shift in philosophy. The mission focus of driving to closure has been replaced by one of enabling the long-term needs of DOE and the nation. Resolving new challenges, such as the disposition of DOE spent nuclear fuel, have been added to EM's responsibilities. In addition, the schedules for addressing several elements of the cleanup mission have been extended. As a result, EM's mission is no longer focused only on driving the current baselines to closure. Meeting the mission will require fundamental advances over at least a 30-year window if not longer as new challenges are added. The

  6. Photonic jet μ-etching: from static to dynamic process

    Science.gov (United States)

    Abdurrochman, A.; Lecler, S.; Zelgowski, J.; Mermet, F.; Fontaine, J.; Tumbelaka, B. Y.

    2017-05-01

    Photonic jet etching is a direct-laser etching method applying photonic jet phenomenon to concentrate the laser beam onto the proceeded material. We call photonic jet the phenomenon of the localized sub-wavelength propagative beam generated at the shadow-side surfaces of micro-scale dielectric cylinders or spheres, when they are illuminated by an electromagnetic plane-wave or laser beam. This concentration has made possible the laser to yield sub-μ etching marks, despite the laser was a near-infrared with nano-second pulses sources. We will present these achievements from the beginning when some spherical glasses were used for static etching to dynamic etching using an optical fiber with a semi-elliptical tip.

  7. Deterministic multimode photonic device for quantum-information processing

    DEFF Research Database (Denmark)

    Nielsen, Anne E. B.; Mølmer, Klaus

    2010-01-01

    We propose the implementation of a light source that can deterministically generate a rich variety of multimode quantum states. The desired states are encoded in the collective population of different ground hyperfine states of an atomic ensemble and converted to multimode photonic states by exci...

  8. On chip frequency discriminator for microwave photonics signal processing

    NARCIS (Netherlands)

    Marpaung, D.A.I.; Roeloffzen, C.G.H.

    2012-01-01

    Microwave photonics (MWP) techniques for the generation, distribution and pro- cessing of radio frequency (RF) signals have enjoyed a surge of interest in the last few years. The workhorse behind these MWP functionalities is a high performance MWP link. Such a link needs to fulfill several criteria

  9. Photonics

    Science.gov (United States)

    1991-01-01

    Optoelectronic materials and devices are examined. Optoelectronic devices, which generate, detect, modulate, or switch electromagnetic radiation are being developed for a variety of space applications. The program includes spatial light modulators, solid state lasers, optoelectronic integrated circuits, nonlinear optical materials and devices, fiber optics, and optical networking photovoltaic technology and optical processing.

  10. Polarization control of intermediate state absorption in resonance-mediated multi-photon absorption process

    International Nuclear Information System (INIS)

    Xu, Shuwu; Yao, Yunhua; Jia, Tianqing; Ding, Jingxin; Zhang, Shian; Sun, Zhenrong; Huang, Yunxia

    2015-01-01

    We theoretically and experimentally demonstrate the control of the intermediate state absorption in an (n + m) resonance-mediated multi-photon absorption process by the polarization-modulated femtosecond laser pulse. An analytical solution of the intermediate state absorption in a resonance-mediated multi-photon absorption process is obtained based on the time-dependent perturbation theory. Our theoretical results show that the control efficiency of the intermediate state absorption by the polarization modulation is independent of the laser intensity when the transition from the intermediate state to the final state is coupled by the single-photon absorption, but will be affected by the laser intensity when this transition is coupled by the non-resonant multi-photon absorption. These theoretical results are experimentally confirmed via a two-photon fluorescence control in (2 + 1) resonance-mediated three-photon absorption of Coumarin 480 dye and a single-photon fluorescence control in (1 + 2) resonance-mediated three-photon absorption of IR 125 dye. (paper)

  11. Scientific Opportunities to Reduce Risk in Nuclear Process Science

    International Nuclear Information System (INIS)

    Bredt, P.R.; Felmy, A.R.; Gauglitz, P.A.; Poloski, A.P.; Vienna, J.D.; Moyer, B.A.; Hobbs, D.; Wilmarth, B.; McIlwain, M.; Subramanian, K.; Krahn, S.; Machara, N.

    2009-01-01

    Cleaning up the nation's nuclear weapons complex remains as one of the most technologically challenging and financially costly problems facing the U.S. Department of Energy (DOE). Safety, cost, and technological challenges have often delayed progress in retrieval, processing, and final disposition of high-level waste, spent nuclear fuel, and challenging materials. Some of the issues result from the difficulty and complexity of the technological issues; others have programmatic bases, such as strategies that may provide undue focus on near-term goals or difficulty in developing and maintaining stakeholder confidence in the proposed solutions. We propose that independent basic fundamental science research addressing the full cleanup life-cycle offers an opportunity to help address these challenges by providing 1) scientific insight into the fundamental mechanisms involved in currently selected processing and disposal options, 2) a rational path to the development of alternative technologies should the primary options fail, 3) confidence that models that predict long-term performance of different disposal options are based upon the best available science, and 4) fundamental science discovery that enables transformational solutions to revolutionize the current baseline processes. Over the last 3 years, DoE's Office of Environmental Management (EM) has experienced a fundamental shift in philosophy. The mission focus of driving to closure has been replaced by one of enabling the long-term needs of DOE and the nation. Resolving new challenges, such as the disposition of DOE spent nuclear fuel, have been added to EM's responsibilities. In addition, the schedules for addressing several elements of the cleanup mission have been extended. As a result, EM's mission is no longer focused only on driving the current baselines to closure. Meeting the mission will require fundamental advances over at least a 30-year window if not longer as new challenges are added. The overall

  12. Embedded RF Photonic Crystals as Routing and Processing Devices in Naval Aperstructures

    National Research Council Canada - National Science Library

    Prather, Dennis W

    2008-01-01

    .... To address these issues, we utilize advanced artificial materials - photonic crystals (PhCs) and meta-material - to construct a sensing head with minaturized antennas as RF receivers and embedded signal channelization for pre-processing...

  13. Processing of transmission data from an uncollimated single photon source

    International Nuclear Information System (INIS)

    Dikaios, N.; Dinelle, K.; Spinks, T.; Nikita, K.; Thielemans, K.

    2006-01-01

    The EXACT 3D PET scanner uses a Cs-137 single photon rotating point source for the transmission scan. As the source is un-collimated, the transmission data are contaminated by scatter. It has been suggested that segmentation of the reconstructed image can restore the quantitative information in the image. We study here if the results can be further improved by the application of a scale factor for every transaxial plane

  14. Suppression of two-photon resonantly enhanced nonlinear processes in extended media

    International Nuclear Information System (INIS)

    Garrett, W.R.; Moore, M.A.; Payne, M.G.; Wunderlich, R.K.

    1988-11-01

    On the basis of combined experimental and theoretical studies of nonlinear processes associated with two-photon excitations near 3d and 4d states in Na, we show how resonantly enhanced stimulated hyper-Raman emission, parametric four-wave mixing processes and total resonant two-photon absorption can become severely suppressed through the actions of internally generated fields on the total atomic response in extended media. 7 refs., 3 figs

  15. Processing multiphoton states through operation on a single photon: Methods and applications

    International Nuclear Information System (INIS)

    Lin Qing; He Bing; Bergou, Janos A.; Ren, Yuhang

    2009-01-01

    Multiphoton states are widely applied in quantum information technology. By the methods presented in this paper, the structure of a multiphoton state in the form of multiple single-photon qubit products can be mapped to a single-photon qudit, which could also be in a separable product with other photons. This makes possible the manipulation of such multiphoton states by processing single-photon states. The optical realization of unknown qubit discrimination [B. He, J. A. Bergou, and Y.-H. Ren, Phys. Rev. A 76, 032301 (2007)] is simplified with the transformation methods. Another application is the construction of quantum logic gates, where the inverse transformations back to the input state spaces are also necessary. We especially show that the modified setups to implement the transformations can realize the deterministic multicontrol gates (including Toffoli gate) operating directly on the products of single-photon qubits.

  16. Graviton production by two photon and electron-photon processes in Kaluza-Klein theories with large extra dimensions

    International Nuclear Information System (INIS)

    Atwood, David; Bar-Shalom, Shaouly; Soni, Amarjit

    2000-01-01

    We consider the production of gravitons via two photon and electron-photon fusion in Kaluza-Klein theories which allow TeV scale gravitational interactions. We show that at electron-positron colliders, the processes l + l - →l + l - +graviton, with l=e, μ, can lead to a new signal of low energy gravity of the form l + l - →l + l - +missing energy which is well above the standard model background. For example, with two extra dimensions, at the Next Linear Collider with a center of mass energy of 500 or 1000 GeV, hundreds to thousands such l + l - +graviton events may be produced if the scale of the gravitational interactions, M D , is around a few TeV. At a gamma-electron collider, more stringent bounds may be placed on M D via the related reaction e - γ→e - G. For instance, if a 1 TeV e + e - collider is converted to an electron-photon collider, a bound of ∼10(14) TeV may be placed on the scale M D if the number of extra dimensions δ=2, while a bound of ∼4(5) TeV may be placed if δ=4, with unpolarized (right polarized) electron beams. (c) 2000 The American Physical Society

  17. On-chip photonic microsystem for optical signal processing based on silicon and silicon nitride platforms

    Science.gov (United States)

    Li, Yu; Li, Jiachen; Yu, Hongchen; Yu, Hai; Chen, Hongwei; Yang, Sigang; Chen, Minghua

    2018-04-01

    The explosive growth of data centers, cloud computing and various smart devices is limited by the current state of microelectronics, both in terms of speed and heat generation. Benefiting from the large bandwidth, promising low power consumption and passive calculation capability, experts believe that the integrated photonics-based signal processing and transmission technologies can break the bottleneck of microelectronics technology. In recent years, integrated photonics has become increasingly reliable and access to the advanced fabrication process has been offered by various foundries. In this paper, we review our recent works on the integrated optical signal processing system. We study three different kinds of on-chip signal processors and use these devices to build microsystems for the fields of microwave photonics, optical communications and spectrum sensing. The microwave photonics front receiver was demonstrated with a signal processing range of a full-band (L-band to W-band). A fully integrated microwave photonics transceiver without the on-chip laser was realized on silicon photonics covering the signal frequency of up 10 GHz. An all-optical orthogonal frequency division multiplexing (OFDM) de-multiplier was also demonstrated and used for an OFDM communication system with the rate of 64 Gbps. Finally, we show our work on the monolithic integrated spectrometer with a high resolution of about 20 pm at the central wavelength of 1550 nm. These proposed on-chip signal processing systems potential applications in the fields of radar, 5G wireless communication, wearable devices and optical access networks.

  18. Opportunity recognition: delineating the process and motivators for serial entrepreneurs

    Directory of Open Access Journals (Sweden)

    Boris Urban

    2011-04-01

    Full Text Available Opportunity recognition is a fundamental research issue in entrepreneurship which this paper empirically investigates for serial entrepreneurs. Initially key definitions and boundary conditions of opportunity recognition are explored to elucidate the relevant motivators driving serial entrepreneurs. After operationalising the various concepts, data is collected by surveying serial entrepreneurs (n= 77 based on pre-determined selection criteria. Since the study’s objective is to build solid theory on these new phenomena, descriptive analysis on the empirical results is provided. To test the hypotheses inferential statistics employing parametric and non-parametric tests are used. The findings reveal that the opportunity recognition behaviours are manifest among serial entrepreneurs, with few significant differences on how many new, major businesses have been pursued, or whether they can be said to be successes.

  19. Uranium mining, processing and nuclear energy - opportunities for Australia?

    International Nuclear Information System (INIS)

    2006-12-01

    electricity production and reduction in volatility arising from input fossil fuel costs; and reduction in greenhouse gas emissions and subsequent effects on global climate. The world's first civilian nuclear reactor commenced operation in 1955. According to the International Energy Agency (IEA), today there are 443 nuclear reactors operating in 31 countries, producing 15 per cent of the world's electricity. As a substantial holder of recoverable reserves (38 per cent of known low cost global reserves) and producer of uranium (23 per cent of global production), Australia is well positioned to increase production and export of uranium oxide to meet market demand. There is an opportunity for Australia to be a participant in the wider nuclear fuel cycle given international confidence in the quality of our production processes, our sophisticated technology community (although no longer with a significant presence in the nuclear fuel cycle) and the strength of our commitment to nuclear non-proliferation. Nuclear power has a much lower greenhouse signature than Australia's current major energy sources for electricity; namely brown and black coal, and gas. Although the priority for Australia will continue to be to reduce carbon dioxide emissions from coal and gas, the Review sees nuclear power as a practical option for part of Australia's electricity production

  20. Parallel processing of dose calculation for external photon beam therapy

    International Nuclear Information System (INIS)

    Kunieda, Etsuo; Ando, Yutaka; Tsukamoto, Nobuhiro; Ito, Hisao; Kubo, Atsushi

    1994-01-01

    We implemented external photon beam dose calculation programs into a parallel processor system consisting of Transputers, 32-bit processors especially suitable for multi-processor configuration. Two network conformations, binary-tree and pipeline, were evaluated for rectangular and irregular field dose calculation algorithms. Although computation speed increased in proportion to the number of CPU, substantial overhead caused by inter-processor communication occurred when a smaller computation load was delivered to each processor. On the other hand, for irregular field calculation, which requires more computation capability for each calculation point, the communication overhead was still less even when more than 50 processors were involved. Real-time responses could be expected for more complex algorithms by increasing the number of processors. (author)

  1. Photon-photon collisions

    International Nuclear Information System (INIS)

    Haissinski, J.

    1986-06-01

    The discussions presented in this paper deal with the following points: distinctive features of gamma-gamma collisions; related processes; photon-photon elastic scattering in the continuum and γγ →gg; total cross section; γγ → V 1 V 2 (V=vector meson); radiative width measurements and light meson spectroscopy; exclusive channels at large /t/; jets and inclusive particle distribution in γγ collisions; and, the photon structure function F γ 2

  2. Analysis of angular momentum properties of photons emitted in fundamental atomic processes

    Science.gov (United States)

    Zaytsev, V. A.; Surzhykov, A. S.; Shabaev, V. M.; Stöhlker, Th.

    2018-04-01

    Many atomic processes result in the emission of photons. Analysis of the properties of emitted photons, such as energy and angular distribution as well as polarization, is regarded as a powerful tool for gaining more insight into the physics of corresponding processes. Another characteristic of light is the projection of its angular momentum upon propagation direction. This property has attracted a special attention over the past decades due to studies of twisted (or vortex) light beams. Measurements being sensitive to this projection may provide valuable information about the role of angular momentum in the fundamental atomic processes. Here we describe a simple theoretical method for determination of the angular momentum properties of the photons emitted in various atomic processes. This method is based on the evaluation of expectation value of the total angular momentum projection operator. To illustrate the method, we apply it to the textbook examples of plane-wave, spherical-wave, and Bessel light. Moreover, we investigate the projection of angular momentum for the photons emitted in the process of the radiative recombination with ionic targets. It is found that the recombination photons do carry a nonzero projection of the orbital angular momentum.

  3. Measurement of the linear polarization of the photons in the elementary processes of bremsstrahlung production

    International Nuclear Information System (INIS)

    Bleier, W.

    1983-01-01

    The polarization of the photons in the elementary processes of the electron-nucleus and electron-electron bremsstrahlung was measured. Electrons with an energy of 300 keV were scattered by copper, gold and carbon target. The polarization in the different processes was measured by using different coincidence methods. (BEF)

  4. Two-photon processes of π0, η, η', ηc and ηb

    International Nuclear Information System (INIS)

    Klabucar, D.

    1997-01-01

    Two-photon processes of π 0 , η, η', η c and η b are studied in the consistently coupled Schwinger-Dyson (SD) and Bethe-Salpeter (BS) approach, where dynamical chiral symmetry breaking (DχSB) is obtained through the SD equation for the quark propagator which is then used in the BS equation. It is shown that the coupled SD-BS approach is similarly successful in the description of two-photon processes of pseudoscalar mesons over a wide range of masses. (K.A.)

  5. Refractories for Industrial Processing. Opportunities for Improved Energy Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Hemrick, James G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hayden, H. Wayne [Metals Manufacture Process and Controls Technology, Inc., Oak Ridge, TN (United States); Angelini, Peter [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Moore, Robert E. [R.E. Moore Associates, Maricopa, AZ (United States); Headrick, William L. [R.E. Moore Associates, Maricopa, AZ (United States)

    2005-01-01

    Refractories are a class of materials of critical importance to manufacturing industries with high-temperature unit processes. This study describes industrial refractory applications and identifies refractory performance barriers to energy efficiency for processing. The report provides recommendations for R&D pathways leading to improved refractories for energy-efficient manufacturing and processing.

  6. Hadronic cross-sections in two photon processes at a future linear collider

    International Nuclear Information System (INIS)

    Godbole, Rohini M.; Roeck, Albert de; Grau, Agnes; Pancheri, Giulia

    2003-01-01

    In this note we address the issue of measurability of the hadronic cross-sections at a future photon collider as well as for the two-photon processes at a future high energy linear e + e - collider. We extend, to higher energy, our previous estimates of the accuracy with which the γ γ cross-section needs to be measured, in order to distinguish between different theoretical models of energy dependence of the total cross-sections. We show that the necessary precision to discriminate among these models is indeed possible at future linear colliders in the Photon Collider option. Further we note that even in the e + e - option a measurement of the hadron production cross-section via γ γ processes, with an accuracy necessary to allow discrimination between different theoretical models, should be possible. We also comment briefly on the implications of these predictions for hadronic backgrounds at the future TeV energy e + e - collider CLIC. (author)

  7. PREFACE: I International Scientific School Methods of Digital Image Processing in Optics and Photonics

    Science.gov (United States)

    Gurov, I. P.; Kozlov, S. A.

    2014-09-01

    The first international scientific school "Methods of Digital Image Processing in Optics and Photonics" was held with a view to develop cooperation between world-class experts, young scientists, students and post-graduate students, and to exchange information on the current status and directions of research in the field of digital image processing in optics and photonics. The International Scientific School was managed by: Saint Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO University) - Saint Petersburg (Russia) Chernyshevsky Saratov State University - Saratov (Russia) National research nuclear University "MEPHI" (NRNU MEPhI) - Moscow (Russia) The school was held with the participation of the local chapters of Optical Society of America (OSA), the Society of Photo-Optical Instrumentation Engineers (SPIE) and IEEE Photonics Society. Further details, including topics, committees and conference photos are available in the PDF

  8. Study of two photon production process in proton-proton collisions at 216 MeV

    International Nuclear Information System (INIS)

    Khrykin, A.S.

    2002-01-01

    The energy spectrum for high energy γ-rays (Eγ ≥ 10 MeV) from the process pp → γγX emitted at 90 deg. in the laboratory frame has been measured at 216 MeV. The resulting photon energy spectrum extracted from γ - γ coincidence events consists of a narrow peak (5.3σ) at a photon energy of about 24 MeV and a relatively broad peak (3.5σ) in the energy range of (50 - 70) MeV. This behavior of the photon energy spectrum is interpreted as a signature of the exotic dibaryon resonance d 1 * with a mass of about 1956 MeV which is assumed to be formed in the radiative process pp → γd 1 * followed by its electromagnetic decay via the d 1 * → ppγ mode. The experimental spectrum is compared with those obtained by means of Monte Carlo simulations

  9. Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Research results of hard photon technology have been summarized as a part of novel technology development highly utilizing the quantum nature of photon. Hard photon technology refers to photon beam technologies which use photon in the 0.1 to 200 nm wavelength region. Hard photon has not been used in industry due to the lack of suitable photon sources and optical devices. However, hard photon in this wavelength region is expected to bring about innovations in such areas as ultrafine processing and material synthesis due to its atom selective reaction, inner shell excitation reaction, and spatially high resolution. Then, technological themes and possibility have been surveyed. Although there are principle proposes and their verification of individual technologies for the technologies of hard photon generation, regulation and utilization, they are still far from the practical applications. For the photon source technology, the laser diode pumped driver laser technology, laser plasma photon source technology, synchrotron radiation photon source technology, and vacuum ultraviolet photon source technology are presented. For the optical device technology, the multi-layer film technology for beam mirrors and the non-spherical lens processing technology are introduced. Also are described the reduction lithography technology, hard photon excitation process, and methods of analysis and measurement. 430 refs., 165 figs., 23 tabs.

  10. Redo log process mining in real life : data challenges & opportunities

    NARCIS (Netherlands)

    González López de Murillas, E.; Hoogendoorn, G.E.; Reijers, H.A.; Teniente, E.; Weidlich, M.

    2018-01-01

    Data extraction and preparation are the most time-consuming phases of any process mining project. Due to the variability on the sources of event data, it remains a highly manual process in most of the cases. Moreover, it is very difficult to obtain reliable event data in enterprise systems that are

  11. Automated Student Aid Processing: The Challenge and Opportunity.

    Science.gov (United States)

    St. John, Edward P.

    1985-01-01

    To utilize automated technology for student aid processing, it is necessary to work with multi-institutional offices (student aid, admissions, registration, and business) and to develop automated interfaces with external processing systems at state and federal agencies and perhaps at need-analysis organizations and lenders. (MLW)

  12. New opportunities for biocatalysis: making pharmaceutical processes greener

    DEFF Research Database (Denmark)

    Woodley, John

    2008-01-01

    The pharmaceutical industry requires synthetic routes to be environmentally compatible as well as to fulfill the demands of process economics and product specification and to continually reduce development times. Biocatalysis has the potential to deliver 'greener' chemical syntheses, and in this ......The pharmaceutical industry requires synthetic routes to be environmentally compatible as well as to fulfill the demands of process economics and product specification and to continually reduce development times. Biocatalysis has the potential to deliver 'greener' chemical syntheses...... of biocatalysis for making pharmaceutical processes greener....

  13. Exploring control parameters of two photon processes in solutions

    Indian Academy of Sciences (India)

    Here, we present the effect of several control parameters on the TPA process that are independent of .... as the typical selection rules and pathways of mole- cular transitions for ..... Inset in the graph shows the 780 beam spec- tra at two ...

  14. Microgravity Processing and Photonic Applications of Organic and Polymeric Materials

    Science.gov (United States)

    Frazier, Donald O.; Paley, Mark S.; Penn, Benjamin G.; Abdeldayem, Hossin A.; Smith, David D.; Witherow, William K.

    1997-01-01

    Some of the primary purposes of this work are to study important technologies, particularly involving thin films, relevant to organic and polymeric materials for improving applicability to optical circuitry and devices and to assess the contribution of convection on film quality in unit and microgravity environments. Among the most important materials processing techniques of interest in this work are solution-based and by physical vapor transport, both having proven gravitational and acceleration dependence. In particular, PolyDiAcetylenes (PDA's) and PhthaloCyanines (Pc's) are excellent NonLinear Optical (NLO) materials with the promise of significantly improved NLO properties through order and film quality enhancements possible through microgravity processing. Our approach is to focus research on integrated optical circuits and optoelectronic devices relevant to solution-based and vapor processes of interest in the Space Sciences Laboratory at the Marshall Space Flight Center (MSFC). Modification of organic materials is an important aspect of achieving more highly ordered structures in conjunction with microgravity processing. Parallel activities include characterization of materials for particular NLO properties and determination of appropriation device designs consistent with selected applications. One result of this work is the determination, theoretically, that buoyancy-driven convection occurs at low pressures in an ideal gas in a thermalgradient from source to sink. Subsequent experiment supports the theory. We have also determined theoretically that buoyancy-driven convection occurs during photodeposition of PDA, an MSFC-patented process for fabricating complex circuits, which is also supported by experiment. Finally, the discovery of intrinsic optical bistability in metal-free Pc films enables the possibility of the development of logic gate technology on the basis of these materials.

  15. Opportunities and challenges for photon diagnostics at the soft X-ray FEL FLASH in simultaneous operation mode (Conference Presentation)

    Science.gov (United States)

    Kuhlmann, Marion; Treusch, Rolf; Plönjes-Palm, Elke; Faatz, Bart; Tiedtke, Kai; Braune, Markus; Keitel, Barbara

    2017-06-01

    FLASH operates two distinguished undulator sections driven by one linear accelerator. In the 11th year of user operation the grown demands for detailed photon beam performances are doubled approached. The more complex machine settings and setup times require a more and more efficient determination of its characteristics concerning electron- and photon-beams. The photon diagnostics systems, e.g. gas monitor detection, photon-ion spectroscopy, or diffractive tools, not only have to deal on a regular basis with fundamental wavelengths between 4nm and 90nm, also they have to be reliable from 1µJ up to 1mJ of average single pulse energy. For the success of the experiments the error bars of many diagnostics measurements need to be pushed into their current limits and developments to go further are always issued. Especial, the pulse duration in conjunction with the spectral width has been accessed in the last year. Direct approaches of fundamental wavelengths below the Nitrogene K-edge and higher harmonics in and below the water window were achieved. While in principal distinguished to each other, the photon diagnostics tools of FLASH1 and FLASH2 add-up to a more complete understanding of the other. Together they allow for a better perspective towards further developments and a more suitable use of beam times. The intermingled knowledge of electron- and photon-beams is essential for an FEL particular in simultaneous operation mode. Examples out of regular user operation and distinguished FEL-studies are given to illustrate the current state of the photon diagnostics at FLASH.

  16. Using GREENSCOPE for Sustainable Process Design: An Educational Opportunity

    Science.gov (United States)

    Increasing sustainability can be approached through the education of those who design, construct, and operate facilities. As chemical engineers learn elements of process systems engineering, they can be introduced to sustainability concepts. The EPA’s GREENSCOPE methodology and...

  17. Electron Beam Processing of Polymers: Facts and Opportunities

    International Nuclear Information System (INIS)

    Gielenz, G.

    2006-01-01

    Electron Beam (EB) processing of polymers is a well established and mature technology in a multitude of industrial polymer applications for more than 40 years. Constant research effort in combination with emerging tailored EB process technologies, have led to numerous new (niche) applications and products within the past decade. Nonetheless, and despite the fact, that nowadays a large variety of EB and related process equipment is readily available for use by the respective industries, EB processing of polymers still takes up only a small niche in comparison to the overall polymer business. In this lecture the author attempts to present a short overview on the current industrial established and emerging radiation processing applications and the related EB equipment suppliers. Then some selected plastics business facts and figures with a forecast of the global plastics consumption situation up to 2010 will be shown. As a conclusion from these facts, some comments will be deduced, regarding the future potential, attractiveness and economical relevance of irradiation processing technologies in present day competitive global markets

  18. Design and demonstration of a multitechnology FPGA for photonic information processing

    Science.gov (United States)

    Mal, Prosenjit; Hawk, Chris; Toshniwal, Kavita; Beyette, Fred R., Jr.

    2003-11-01

    We present here a novel architecture for a multi-technology field programmabler gate array (MT-FPGA). Implemented with a conventional CMOS VLSI technology the architecture is suitable for prototyping photonic information processing systems. We report here that this new FPGA architecture will enable the design of reconfigurable systems that incorporate technologies outside the traditional electronic domain.

  19. Low-energy photon-neutrino inelastic processes beyond the Standard Model

    CERN Document Server

    Abada, A.; Pittau, R.

    1999-01-01

    We investigate in this work the leading contributions of the MSSM with R-parity violation and of Left-Right models to the low-energy five-leg photon-neutrino processes. We discuss the results and compare them to the Standard Model ones.

  20. Nonlinear Silicon Photonic Signal Processing Devices for Future Optical Networks

    Directory of Open Access Journals (Sweden)

    Cosimo Lacava

    2017-01-01

    Full Text Available In this paper, we present a review on silicon-based nonlinear devices for all optical nonlinear processing of complex telecommunication signals. We discuss some recent developments achieved by our research group, through extensive collaborations with academic partners across Europe, on optical signal processing using silicon-germanium and amorphous silicon based waveguides as well as novel materials such as silicon rich silicon nitride and tantalum pentoxide. We review the performance of four wave mixing wavelength conversion applied on complex signals such as Differential Phase Shift Keying (DPSK, Quadrature Phase Shift Keying (QPSK, 16-Quadrature Amplitude Modulation (QAM and 64-QAM that dramatically enhance the telecom signal spectral efficiency, paving the way to next generation terabit all-optical networks.

  1. Manipulation of multi-photon-entanglement. Applications in quantum information processing

    International Nuclear Information System (INIS)

    Goebel, Alexander Matthias

    2008-01-01

    Over the last twenty years the field of quantum information processing (QIP) has attracted the attention of many scientists, due to the promise of impressive improvements in the areas of computational speed, communication security and the ability to simulate nature on the micro scale. This thesis describes an experimental work on the physics of multi-photon entanglement and its application in the field of QIP. We have thoroughly developed the necessary techniques to generate multipartite entanglement between up to six photons. By exploiting the developed six-photon interferometer, in this thesis we report for the first time the experimental quantum teleportation of a two-qubit composite system, the realization of multi-stage entanglement swapping, the implementation of a teleportation-based controlled-NOT gate for fault-tolerant quantum computation, the first generation of entanglement in sixpartite photonic graph states and the realization of 'one-way' quantum computation with two-photon four-qubit cluster states. The methods developed in these experiments are of great significance both for exploring the field of QIP and for future experiments on the fundamental tests of quantum mechanics. (orig.)

  2. Manipulation of multi-photon-entanglement. Applications in quantum information processing

    Energy Technology Data Exchange (ETDEWEB)

    Goebel, Alexander Matthias

    2008-07-16

    Over the last twenty years the field of quantum information processing (QIP) has attracted the attention of many scientists, due to the promise of impressive improvements in the areas of computational speed, communication security and the ability to simulate nature on the micro scale. This thesis describes an experimental work on the physics of multi-photon entanglement and its application in the field of QIP. We have thoroughly developed the necessary techniques to generate multipartite entanglement between up to six photons. By exploiting the developed six-photon interferometer, in this thesis we report for the first time the experimental quantum teleportation of a two-qubit composite system, the realization of multi-stage entanglement swapping, the implementation of a teleportation-based controlled-NOT gate for fault-tolerant quantum computation, the first generation of entanglement in sixpartite photonic graph states and the realization of 'one-way' quantum computation with two-photon four-qubit cluster states. The methods developed in these experiments are of great significance both for exploring the field of QIP and for future experiments on the fundamental tests of quantum mechanics. (orig.)

  3. Stereolithographic processing of ceramics: Photon diffusion in colloidal dispersion

    Science.gov (United States)

    Garg, Rajeev

    The technique of ceramic stereolithography (CSL) has been developed for fabricating near net shape ceramic objects. In stereolithography, the three-dimensional computer design file of the object is sliced into thin layers. Each layer is physically fabricated by photocuring the surface of a liquid photo-polymerizable resin bath by raster scanning an ultra-violet laser across the surface of the resin. In CSL, the liquid resin is a high concentration colloidal dispersion in a solution of ultraviolet curable polymers. The ceramic green body fabricated by ceramic stereolithography technique is subjected to the post processing steps of drying, binder burnout and sintering to form a dense ceramic object. An aqueous alumina dispersion in photocuring polymers with particle volume fraction greater than 0.5 was formulated for CSL process. Low molecular weight solution polymers were found to be best suited for formulating ceramic resins due to their inherently low viscosity and favorable interactions with the ceramic dispersant. A hydroxyapatite ceramic resin was also developed for the use in the CSL technique. A model is developed to describe the photocuring process in concentrated ceramic dispersion. The curing profile in ceramic dispersion is governed by multiple scattering from the ceramic particles and absorption by the photocuring polymers. Diffusion theory of light transport is used to model the multiple scattering and absorption phenomena. It is found that diffusive transport adequately describes the phenomena of laser pulse propagation in highly concentrated colloidal dispersions. A model was developed to describe the absorption in highly concentrated ceramic dispersion. Various complex-shaped monolithic alumina and hydroxyapatite objects were fabricated by CSL and shown to possess uniform microstructure. The mechanical properties and sintering behavior of the parts fabricated by CSL are shown to be comparable to those fabricated by other ceramic processing technique

  4. Opportunities in the United States' gas processing industry

    International Nuclear Information System (INIS)

    Meyer, H.S.; Leppin, D.

    1997-01-01

    To keep up with the increasing amount of natural gas that will be required by the market and with the decreasing quality of the gas at the well-head, the gas processing industry must look to new technologies to stay competitive. The Gas Research Institute (GR); is managing a research, development, design and deployment program that is projected to save the industry US dollar 230 million/year in operating and capital costs from gas processing related activities in NGL extraction and recovery, dehydration, acid gas removal/sulfur recovery, and nitrogen rejection. Three technologies are addressed here. Multivariable Control (MVC) technology for predictive process control and optimization is installed or in design at fourteen facilities treating a combined total of over 30x10 9 normal cubic meter per year (BN m 3 /y) [1.1x10 12 standard cubic feet per year (Tcf/y)]. Simple pay backs are typically under 6 months. A new acid gas removal process based on n-formyl morpholine (NFM) is being field tested that offers 40-50% savings in operating costs and 15-30% savings in capital costs relative to a commercially available physical solvent. The GRI-MemCalc TM Computer Program for Membrane Separations and the GRI-Scavenger CalcBase TM Computer Program for Scavenging Technologies are screening tools that engineers can use to determine the best practice for treating their gas. (au) 19 refs

  5. Blockchains for business process management - Challenges and opportunities

    NARCIS (Netherlands)

    Mendling, Jan; Weber, Ingo; Van Der Aalst, Wil; Brocke, Jan Vom; Cabanillas, Cristina; Daniel, Florian; Debois, Søren; Di Ciccio, Claudio; Dumas, Marlon; Dustdar, Schahram; Gal, Avigdor; García-Bañuelos, Luciano; Governatori, Guido; Hull, Richard; La Rosa, Marcello; Leopold, Henrik; Leymann, Frank; Recker, Jan; Reichert, Manfred; Reijers, Hajo A.; Rinderlema, Stefanie; Solti, Andreas; Rosemann, Michael; Schulte, Stefan; Singh, Munindar P.; Slaats, Tijs; Staples, Mark; Weber, Barbara; Weidlich, Matthias; Weske, Mathias; Xu, Xiwei; Zhu, Liming

    Blockchain technology ofers a sizable promise to rethink the way interorganizational business processes are managed because of its potential to realize execution without a central party serving as a single point of trust (and failure). To stimulate research on this promise and the limits thereof, in

  6. Blockchains for business process management - Challenges and opportunities

    NARCIS (Netherlands)

    Mendling, J.; Weber, I.; van der Aalst, W.M.P.; vom Brocke, J.; Cabanillas, C.; Daniel, F.; Debois, S.; Di Ciccio, C.; Dumas, M.; Dustdar, S.; Gal, A.; García-Bañuelos, L.; Governatori, G.; Hull, R.; La Rosa, Marcello; Leopold, Henrik; Leymann, Frank; Recker, Jan; Reichert, Manfred; Reijers, H.A.; Rinderlema, Stefanie; Solti, Andreas; Rosemann, Michael; Schulte, Stefan; Singh, Munindar P.; Slaats, T.; Staples, Mark; Weber, Barbara; Weidlich, Matthias; Weske, Mathias; Xu, Xiwei; Zhu, Liming

    2018-01-01

    Blockchain technology ofers a sizable promise to rethink the way interorganizational business processes are managed because of its potential to realize execution without a central party serving as a single point of trust (and failure). To stimulate research on this promise and the limits thereof, in

  7. Statistical Process Control. Impact and Opportunities for Ohio.

    Science.gov (United States)

    Brown, Harold H.

    The first purpose of this study is to help the reader become aware of the evolution of Statistical Process Control (SPC) as it is being implemented and used in industry today. This is approached through the presentation of a brief historical account of SPC, from its inception through the technological miracle that has occurred in Japan. The…

  8. Microscale technology and biocatalytic processes: Opportunities and challenges for synthesis

    DEFF Research Database (Denmark)

    Wohlgemuth, Roland; Plazl, Igor; Žnidaršič-Plazl, Polona

    2015-01-01

    Despite the expanding presence of microscale technology in chemical synthesis and energy production as well as in biomedical devices and analytical and diagnostic tools, its potential in biocatalytic processes for pharmaceutical and fine chemicals, as well as related industries, has not yet been...

  9. Strong-field QED processes in short laser pulses. One- and two-photon Compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Seipt, Daniel

    2012-12-20

    The purpose of this thesis is to advance the understanding of strong-field QED processes in short laser pulses. The processes of non-linear one-photon and two-photon Compton scattering are studied, that is the scattering of photons in the interaction of relativistic electrons with ultra-short high-intensity laser pulses. These investigations are done in view of the present and next generation of ultra-high intensity optical lasers which are supposed to achieve unprecedented intensities of the order of 10{sup 24} W/cm{sup 2} and beyond, with pulse lengths in the order of some femtoseconds. The ultra-high laser intensity requires a non-perturbative description of the interaction of charged particles with the laser field to allow for multi-photon interactions, which is beyond the usual perturbative expansion of QED organized in powers of the fine structure constant. This is achieved in strong-field QED by employing the Furry picture and non-perturbative solutions of the Dirac equation in the presence of a background laser field as initial and final state wave functions, as well as the laser dressed Dirac-Volkov propagator. The primary objective is a realistic description of scattering processes with regard to the finite laser pulse duration beyond the common approximation of infinite plane waves, which is made necessary by the ultra-short pulse length of modern high-intensity lasers. Non-linear finite size effects are identified, which are a result of the interplay between the ultra-high intensity and the ultra-short pulse length. In particular, the frequency spectra and azimuthal photon emission spectra are studied emphasizing the differences between pulsed and infinite laser fields. The proper description of the finite temporal duration of the laser pulse leads to a regularization of unphysical infinities (due to the infinite plane-wave description) of the laser-dressed Dirac-Volkov propagator and in the second-order strong-field process of two-photon Compton

  10. New design for photonic temporal integration with combined high processing speed and long operation time window.

    Science.gov (United States)

    Asghari, Mohammad H; Park, Yongwoo; Azaña, José

    2011-01-17

    We propose and experimentally prove a novel design for implementing photonic temporal integrators simultaneously offering a high processing bandwidth and a long operation time window, namely a large time-bandwidth product. The proposed scheme is based on concatenating in series a time-limited ultrafast photonic temporal integrator, e.g. implemented using a fiber Bragg grating (FBG), with a discrete-time (bandwidth limited) optical integrator, e.g. implemented using an optical resonant cavity. This design combines the advantages of these two previously demonstrated photonic integrator solutions, providing a processing speed as high as that of the time-limited ultrafast integrator and an operation time window fixed by the discrete-time integrator. Proof-of-concept experiments are reported using a uniform fiber Bragg grating (as the original time-limited integrator) connected in series with a bulk-optics coherent interferometers' system (as a passive 4-points discrete-time photonic temporal integrator). Using this setup, we demonstrate accurate temporal integration of complex-field optical signals with time-features as fast as ~6 ps, only limited by the processing bandwidth of the FBG integrator, over time durations as long as ~200 ps, which represents a 4-fold improvement over the operation time window (~50 ps) of the original FBG integrator.

  11. Photonic single nonlinear-delay dynamical node for information processing

    Science.gov (United States)

    Ortín, Silvia; San-Martín, Daniel; Pesquera, Luis; Gutiérrez, José Manuel

    2012-06-01

    An electro-optical system with a delay loop based on semiconductor lasers is investigated for information processing by performing numerical simulations. This system can replace a complex network of many nonlinear elements for the implementation of Reservoir Computing. We show that a single nonlinear-delay dynamical system has the basic properties to perform as reservoir: short-term memory and separation property. The computing performance of this system is evaluated for two prediction tasks: Lorenz chaotic time series and nonlinear auto-regressive moving average (NARMA) model. We sweep the parameters of the system to find the best performance. The results achieved for the Lorenz and the NARMA-10 tasks are comparable to those obtained by other machine learning methods.

  12. Photon-photon collisions, and other processes without annihilation, in e{sup -} e{sup ±} storage rings; Collisions photon-photon, et autres processus sans annihilation dans les anneaux de stockage e{sup -} e{sup ±}

    Energy Technology Data Exchange (ETDEWEB)

    Parisi, Joseph Robert

    1974-02-19

    Chapter 1: The author here presents the historical development of the idea of photon-photon collisions in electron-positron (or electron-electron) storage rings. He shows in particular the considerations which guided the work of the College de France group since this work was started in 1969. A brief review is given of the various developments of the field in the last four years. The fundamental problem of the 'tagging' of the outgoing electrons is mentioned. Chapter 2: We study the conditions which allow the rejection of the background provided by the 'heavy photon Bremsstrahlung' diagram of the same order in Q E D as the photon-photon collision diagram. We show that this background is totally negligible in the case of 'double tagging' (both electrons detected near 0 deg.). In the case of 'single tagging' (one electron detected at large angle and the other one near 0 deg.), it appears that the background can become dangerous already at moderately large values of θ when resonant enhancements (ρ, φ, ρ''') are present. Also in the case of 'no tagging' or 'tagging through absence' (i. e. checking, in e{sup +} e{sup -} collisions, that the electrons are not scattered at large angle), it is essentially near the resonant enhancements that the background becomes about as large or larger than the γγ collision term. Various means of reducing it or eliminating it even in those cases are discussed. Chapter 3: We here consider some general features of photon-photon collision processes, in the case of double tagging; dependence on θ{sub max} (maximal tagging angle of both electrons); dependence on the beam energy; angular distributions of the particles A{sup ±} produced. We then introduce realistic experimental conditions, in particular two cutoff parameters: a minimal emission angle ψ{sub min} for the particles produced, and a minimal relative energy loss χ{sub min} for the outgoing electrons. The effect of these parameters on the invariant mass spectrum of the pair

  13. Radiation processing of food and agricultural commodities: opportunities and challenges

    International Nuclear Information System (INIS)

    Sharma, Arun

    2009-01-01

    Assuring adequate food security to citizens of the country requires deployment of strategies for augmenting agricultural production while eliminating post-harvest losses. Appropriate post-harvest processing, handling, storage and distribution practices are as important as the efforts to increase productivity for sustained food security, food safety and international trade in agricultural commodities. Nuclear energy can play a significant role both in the improvement of crop productivity, as well as, in the preservation and hygienization of agricultural produce

  14. Extra-terrestrial construction processes - Advancements, opportunities and challenges

    Science.gov (United States)

    Lim, Sungwoo; Prabhu, Vibha Levin; Anand, Mahesh; Taylor, Lawrence A.

    2017-10-01

    Government space agencies, including NASA and ESA, are conducting preliminary studies on building alternative space-habitat systems for deep-space exploration. Such studies include development of advanced technologies for planetary surface exploration, including an in-depth understanding of the use of local resources. Currently, NASA plans to land humans on Mars in the 2030s. Similarly, other space agencies from Europe (ESA), Canada (CSA), Russia (Roscosmos), India (ISRO), Japan (JAXA) and China (CNSA) have already initiated or announced their plans for launching a series of lunar missions over the next decade, ranging from orbiters, landers and rovers for extended stays on the lunar surface. As the Space Odyssey is one of humanity's oldest dreams, there has been a series of research works for establishing temporary or permanent settlement on other planetary bodies, including the Moon and Mars. This paper reviews current projects developing extra-terrestrial construction, broadly categorised as: (i) ISRU-based construction materials; (ii) fabrication methods; and (iii) construction processes. It also discusses four categories of challenges to developing an appropriate construction process: (i) lunar simulants; (ii) material fabrication and curing; (iii) microwave-sintering based fabrication; and (iv) fully autonomous and scaled-up construction processes.

  15. The Role of External Knowledge Sources and Organizational Design in the Process of Opportunity Exploitation

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Lyngsie, Jacob; A. Zahra, Shaker

    involving 536 Danish firms shows that the use of external knowledge sources is positively associated with opportunity exploitation, but the strength of this association is significantly influenced by organizational designs that enable the firm to access external knowledge during the process of exploiting......Research highlights the role of external knowledge sources in the recognition of strategic opportunities, but is less forthcoming with respect to the role of such sources during the process of exploiting or realizing opportunities. We build on the knowledge-based view to propose that realizing...... opportunities often involves significant interactions with external knowledge sources. Organizational design can facilitate a firm’s interactions with these sources, while achieving coordination among organizational members engaged in opportunity exploitation. Our analysis of a double-respondent survey...

  16. The Role of External Knowledge Sources and Organizational Design in the Process of Opportunity Exploitation

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Lyngsie, Jacob; Zahra, Shaker A.

    2013-01-01

    involving 536 Danish firms shows that the use of external knowledge sources is positively associated with opportunity exploitation, but the strength of this association is significantly influenced by organizational designs that enable the firm to access external knowledge during the process of exploiting......Research highlights the role of external knowledge sources in the recognition of strategic opportunities but is less forthcoming with respect to the role of such sources during the process of exploiting or realizing opportunities. We build on the knowledge-based view to propose that realizing...... opportunities often involves significant interactions with external knowledge sources. Organizational design can facilitate a firm's interactions with these sources, while achieving coordination among organizational members engaged in opportunity exploitation. Our analysis of a double-respondent survey...

  17. Polychromatic photons

    DEFF Research Database (Denmark)

    Keller, Ole

    2002-01-01

    train quantum electrodynamics. A brief description of particle (photon) position operators is given, and it is shown that photons usually are only algebraically confined in an emission process. Finally, it is demonstrated that the profile of the birth domain of a radio-frequency photon emitted...

  18. Guide to resource conservation and cost savings opportunities in the dairy processing sector

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This guide identifies and promotes opportunities for conserving energy and water, as well as reducing waste, in the dairy processing sector. The guide begins with an introduction and a profile of Ontario`s dairy processing sector, outlining the context for resource conservation and cost savings opportunities. It then outlines the rationale and the generic processes selected for careful examination of resource conservation and cost savings opportunities. Subsequent chapters describe the energy, water, and material resources commonly used in relation to the generic processes; the air, water, and solid waste residuals commonly derived from those processes; and new technologies with potential application in dairy processing. The generic processes covered in the guide are for fluid milk, cheese, ice cream and frozen products, cultured products such as yogurt, butter, and dried or evaporated products. The report ends with additional useful information for dairy processors.

  19. Mobility as Progressivity: Ranking Income Processes According to Equality of Opportunity

    OpenAIRE

    Roland Benabou; Efe A. Ok

    2001-01-01

    Interest in economic mobility stems largely from its perceived role as an equalizer of opportunities, though not necessarily of outcomes. In this paper we show that this view leads very naturally to a methodology for the measurement of social mobility which has strong parallels with the theory of progressive taxation. We characterize opportunity--equalizing mobility processes, and provide simple criteria to determine when one process is more equalizing than another. We then explain how this m...

  20. Poisson pre-processing of nonstationary photonic signals: Signals with equality between mean and variance.

    Science.gov (United States)

    Poplová, Michaela; Sovka, Pavel; Cifra, Michal

    2017-01-01

    Photonic signals are broadly exploited in communication and sensing and they typically exhibit Poisson-like statistics. In a common scenario where the intensity of the photonic signals is low and one needs to remove a nonstationary trend of the signals for any further analysis, one faces an obstacle: due to the dependence between the mean and variance typical for a Poisson-like process, information about the trend remains in the variance even after the trend has been subtracted, possibly yielding artifactual results in further analyses. Commonly available detrending or normalizing methods cannot cope with this issue. To alleviate this issue we developed a suitable pre-processing method for the signals that originate from a Poisson-like process. In this paper, a Poisson pre-processing method for nonstationary time series with Poisson distribution is developed and tested on computer-generated model data and experimental data of chemiluminescence from human neutrophils and mung seeds. The presented method transforms a nonstationary Poisson signal into a stationary signal with a Poisson distribution while preserving the type of photocount distribution and phase-space structure of the signal. The importance of the suggested pre-processing method is shown in Fano factor and Hurst exponent analysis of both computer-generated model signals and experimental photonic signals. It is demonstrated that our pre-processing method is superior to standard detrending-based methods whenever further signal analysis is sensitive to variance of the signal.

  1. Opportunities for Process Monitoring Techniques at Delayed Access Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, Michael M.; Gitau, Ernest TN; Johnson, Shirley J.; Schanfein, Mark; Toomey, Christopher

    2013-09-20

    Except for specific cases where the International Atomic Energy Agency (IAEA) maintains a continuous presence at a facility (such as the Japanese Rokkasho Reprocessing Plant), there is always a period of time or delay between the moment a State is notified or aware of an upcoming inspection, and the time the inspector actually enters the material balance area or facility. Termed by the authors as “delayed access,” this period of time between inspection notice and inspector entrance to a facility poses a concern. Delayed access also has the potential to reduce the effectiveness of measures applied as part of the Safeguards Approach for a facility (such as short-notice inspections). This report investigates the feasibility of using process monitoring to address safeguards challenges posed by delayed access at a subset of facility types.

  2. Development of a Monte Carlo software to photon transportation in voxel structures using graphic processing units

    International Nuclear Information System (INIS)

    Bellezzo, Murillo

    2014-01-01

    As the most accurate method to estimate absorbed dose in radiotherapy, Monte Carlo Method (MCM) has been widely used in radiotherapy treatment planning. Nevertheless, its efficiency can be improved for clinical routine applications. In this thesis, the CUBMC code is presented, a GPU-based MC photon transport algorithm for dose calculation under the Compute Unified Device Architecture (CUDA) platform. The simulation of physical events is based on the algorithm used in PENELOPE, and the cross section table used is the one generated by the MATERIAL routine, also present in PENELOPE code. Photons are transported in voxel-based geometries with different compositions. There are two distinct approaches used for transport simulation. The rst of them forces the photon to stop at every voxel frontier, the second one is the Woodcock method, where the photon ignores the existence of borders and travels in homogeneous fictitious media. The CUBMC code aims to be an alternative of Monte Carlo simulator code that, by using the capability of parallel processing of graphics processing units (GPU), provide high performance simulations in low cost compact machines, and thus can be applied in clinical cases and incorporated in treatment planning systems for radiotherapy. (author)

  3. Parallel photonic information processing at gigabyte per second data rates using transient states

    Science.gov (United States)

    Brunner, Daniel; Soriano, Miguel C.; Mirasso, Claudio R.; Fischer, Ingo

    2013-01-01

    The increasing demands on information processing require novel computational concepts and true parallelism. Nevertheless, hardware realizations of unconventional computing approaches never exceeded a marginal existence. While the application of optics in super-computing receives reawakened interest, new concepts, partly neuro-inspired, are being considered and developed. Here we experimentally demonstrate the potential of a simple photonic architecture to process information at unprecedented data rates, implementing a learning-based approach. A semiconductor laser subject to delayed self-feedback and optical data injection is employed to solve computationally hard tasks. We demonstrate simultaneous spoken digit and speaker recognition and chaotic time-series prediction at data rates beyond 1Gbyte/s. We identify all digits with very low classification errors and perform chaotic time-series prediction with 10% error. Our approach bridges the areas of photonic information processing, cognitive and information science.

  4. Restricted conformal invariance in QCD and its predictive power for virtual two-photon processes

    CERN Document Server

    Müller, D

    1998-01-01

    The conformal algebra provides powerful constraints, which guarantee that renormalized conformally covariant operators exist in the hypothetical conformal limit of the theory, where the $\\beta$-function vanishes. Thus, in this limit also the conformally covariant operator product expansion on the light cone holds true. This operator product expansion has predictive power for two-photon processes in the generalized Bjorken region. Only the Wilson coefficients and the anomalous dimensions that are known from deep inelastic scattering are required for the prediction of all other two-photon processes in terms of the process-dependent off-diagonal expectation values of conformal operators. It is checked that the next-to-leading order calculations for the flavour non-singlet meson transition form factors are consistent with the corrections to the corresponding Wilson coefficients in deep inelasitic scattering.

  5. High performance printed oxide field-effect transistors processed using photonic curing

    Science.gov (United States)

    Garlapati, Suresh Kumar; Cadilha Marques, Gabriel; Gebauer, Julia Susanne; Dehm, Simone; Bruns, Michael; Winterer, Markus; Baradaran Tahoori, Mehdi; Aghassi-Hagmann, Jasmin; Hahn, Horst; Dasgupta, Subho

    2018-06-01

    Oxide semiconductors are highly promising candidates for the most awaited, next-generation electronics, namely, printed electronics. As a fabrication route for the solution-processed/printed oxide semiconductors, photonic curing is becoming increasingly popular, as compared to the conventional thermal curing method; the former offers numerous advantages over the latter, such as low process temperatures and short exposure time and thereby, high throughput compatibility. Here, using dissimilar photonic curing concepts (UV–visible light and UV-laser), we demonstrate facile fabrication of high performance In2O3 field-effect transistors (FETs). Beside the processing related issues (temperature, time etc.), the other known limitation of oxide electronics is the lack of high performance p-type semiconductors, which can be bypassed using unipolar logics from high mobility n-type semiconductors alone. Interestingly, here we have found that our chosen distinct photonic curing methods can offer a large variation in threshold voltage, when they are fabricated from the same precursor ink. Consequently, both depletion and enhancement-mode devices have been achieved which can be used as the pull-up and pull-down transistors in unipolar inverters. The present device fabrication recipe demonstrates fast processing of low operation voltage, high performance FETs with large threshold voltage tunability.

  6. EQUAL EMPLOYMENT OPPORTUNITIES IN THE RECRUITMENT AND SELECTION PROCESS OF HUMAN RESOURCES

    Directory of Open Access Journals (Sweden)

    Aleksandra Stoilkovska

    2015-12-01

    Full Text Available The aim of this article is to examine the problem of the concept of equal employment opportunities in the HR recruitment and selection process. Due to the fact that in these processes, both the HR managers and the applicants are involved, this research is conducted separately among them. Thus, it will be determined if both sides share the same opinion with respect to the existence of this concept in the mentioned processes. Providing equal employment opportunities is crucial for any company and represents a key for selecting the real employees. Therefore, the research includes the existence of prejudices in the recruitment and selection process such as discrimination based on national and social origin, gender and sexual orientation, age, political affiliation etc. As an essential part of this concept, the legislation in the Republic of Macedonia and its impact in the process of generating equal opportunities will be considered.

  7. Spin coating and plasma process for 2.5D integrated photonics on multilayer polymers

    International Nuclear Information System (INIS)

    Zebda, A.; Camberlein, L.; Beche, B.; Gaviot, E.; Beche, E.; Duval, D.; Zyss, J.; Jezequel, G.; Solal, F.; Godet, C.

    2008-01-01

    Polymer spin coating, surface plasma treatment and selective UV-lithography processes have been developed to realize 2.5D photonic micro-resonators, made of disk- or ring-shaped upper rib waveguides, using common polymers such as SU8 (biphenol A ether glycidyl), PS233 (polymeric silane) and SOG (siloxane Spin on Glass). Both oxygen and argon plasma treatments, applied to PS233 and SOG before spin-coating the SU8, improve substantially the grip of multilayer devices (SU8 / PS233 or SU8 / SOG). Surface energy components derived from contact angle measurements have been used to optimize the processing conditions. In such integrated photonic devices, the both single-electromagnetic-modes called transverse electric (TE 00 ) and transverse magnetic (TM 00 ) have been excited in a SU8 micro-disk, with a single mode propagation strongly localized near the edge of the disk (i.e. the so called whispering gallery modes)

  8. One photon exchange processes and the calibration of polarization of high energy protons

    International Nuclear Information System (INIS)

    Margolis, B.; Thomas, G.H.

    1978-01-01

    Polarization phenomena in small momentum transfer high energy one-photon exchange processes in the reaction p + A → X + A where A is a complex nucleus and X is anything are examined. It is shown that these polarizations can be related directly to photoproduction polarization effects in the reaction γ + p → X at low energies. Explicit formulae are written for polarization effects in the case where X → π 0 + p

  9. Photonic Ultra-Wideband 781.25-Mb/s Signal Generation and Transmission Incorporating Digital Signal Processing Detection

    DEFF Research Database (Denmark)

    Gibbon, Timothy Braidwood; Yu, Xianbin; Tafur Monroy, Idelfonso

    2009-01-01

    The generation of photonic ultra-wideband (UWB) impulse signals using an uncooled distributed-feedback laser is proposed. For the first time, we experimentally demonstrate bit-for-bit digital signal processing (DSP) bit-error-rate measurements for transmission of a 781.25-Mb/s photonic UWB signal...

  10. Study the multi-photon absorption process in two types of molecules

    International Nuclear Information System (INIS)

    Al-azawi, H.R.

    1986-01-01

    The aim of the present work was to study the multi-photon absorption process in two types of molecules; spherical top such as SF 6 molecules and assymetric top such as CHOOH and C 2 H 4 molecules. This work also aimed to study the effect of buffer gas pressure (Ar), which is transparent to the infrared (IR) laser on the multiphoton absorption of both types of molecules. A pulsed (TEA) CO 2 laser was used as a source which generates multi-lines in the IR-region of the spectrum and an optoacoustic detector was used to detect the energy absorbed by the molecules. In this study, the relaxation process was found to be faster in the heavy molecules than that in the light ones. A limit in the Ar pressure was observed. Below this limit, the gas acted as an active buffer gas and above it, the multi-photon absorption process was quenched. This work also aimed to study the multi-photon absorption spectrum for the CHOOH molecules in the range (1067-1090 cm -1 ). This spectrum was found to be consistent with the linear absorption spectrum obtained for the same range. The density of the vibrational states as a function of the vibrational energy was studied for the molecules SF 6 , CHOOH and C 2 H 4 . The results were used to interpret (i) the difference in the energy absorbed by difference molecules at the same energy density and (ii) the non-linearity in the multi-photon absorption for CHOOH molecules. 1 tab.; 40 figs.; 70 refs

  11. FY 2000 report on the results of the research and development project for the photon-aided instrumentation and processing technologies. R and D of the photon-aided instrumentation and processing technologies; 2000 nendo photon keisoku kako gijutsu seika hokokusho. Photon keisoku kako gijutsu no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Described herein are the FY 2000 results of development of the photon-aided instrumentation and processing technologies. The technological and R and D trends of the photon-aided instrumentation and processing technologies are surveyed, in order to clarify the directions of their impacts and ripple effects on creation of new industries and development of the existing industries. The survey committee is organized, for exchanging opinions and information, and collection of information. For the trends of the photon-aided processing technologies, information on the elementary and peripheral technologies is collected by literature survey and academic meetings for processing, applied instrumentation and analysis, and photon generation/controlling, to grasp, analyze and study the latest trends. For the photon-utilizing technologies, information is collected viewed from their application to wide industrial areas, e.g., medical, diagnostic, communication/transmission, multimedia and chemical areas, other than those for instrumentation and processing. Also surveyed and analyzed/studied are the technologies for environmental protection, sensing, information, and the new areas, e.g., terahertz photonics and agriculture. (NEDO)

  12. Photon-photon collisions

    International Nuclear Information System (INIS)

    Field, J.H.

    1984-01-01

    The current status, both theoretical and experimental, of two photon collision physics is reviewed with special emphasis on recent experimental results from e + e - storage rings. After a complete presentation of the helicity amplitude formalism for the general process e + e - → Xe + e - , various approximations (transverse photon, Weisaecker Williams) are discussed. Beam polarisation effects and radiative corrections are also briefly considered. A number of specific processes, for which experimental results are now available, are then described. In each case existing theoretical prediction are confronted with experimental results. The processes described include single resonance production, lepton and hadron pair production, the structure functions of the photon, the production of high Psub(T) jets and the total photon photon cross section. In the last part of the review the current status of the subject is summarised and some comments are made on future prospects. These include both extrapolations of current research to higher energy machines (LEP, HERA) as well as a brief mention of both the technical realisation and the physics interest of the real γγ and eγ collisions which may be possible using linear electron colliders in the 1 TeV energy range

  13. Reconfigurable Photonic Crystals Enabled by Multistimuli-Responsive Shape Memory Polymers Possessing Room Temperature Shape Processability.

    Science.gov (United States)

    Fang, Yin; Leo, Sin-Yen; Ni, Yongliang; Wang, Junyu; Wang, Bingchen; Yu, Long; Dong, Zhe; Dai, Yuqiong; Basile, Vito; Taylor, Curtis; Jiang, Peng

    2017-02-15

    Traditional shape memory polymers (SMPs) are mostly thermoresponsive, and their applications in nano-optics are hindered by heat-demanding programming and recovery processes. By integrating a polyurethane-based shape memory copolymer with templating nanofabrication, reconfigurable/rewritable macroporous photonic crystals have been demonstrated. This SMP coupled with the unique macroporous structure enables unusual all-room-temperature shape memory cycles. "Cold" programming involving microscopic order-disorder transitions of the templated macropores is achieved by mechanically deforming the macroporous SMP membranes. The rapid recovery of the permanent, highly ordered photonic crystal structure from the temporary, disordered configuration can be triggered by multiple stimuli including a large variety of vapors and solvents, heat, and microwave radiation. Importantly, the striking chromogenic effects associated with these athermal and thermal processes render a sensitive and noninvasive optical methodology for quantitatively characterizing the intriguing nanoscopic shape memory effects. Some critical parameters/mechanisms that could significantly affect the final performance of SMP-based reconfigurable photonic crystals including strain recovery ratio, dynamics and reversibility of shape recovery, as well as capillary condensation of vapors in macropores, which play a crucial role in vapor-triggered recovery, can be evaluated using this new optical technology.

  14. Multi-photon processes brought about by a laser; Processus multiphotoniques provoques par un laser

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    We calculate the critical intensity characterizing the multiphoton processes. The multiphoton effects corresponding to the Compton scattering, the Bremsstrahlung, the photoelectric effect are investigated. The cross sections are evaluated. We show how the introduction of a refractive index, in clothing the photons, allows the elimination of the infrared divergence. The theory seems consistent with experiment. (author) [French] Nous calculons l'intensite critique caracterisant les processus multiphotoniques. Les effets multiphotoniques correspondant a la diffusion Compton, au bremsstrahlung, a l'effet photoelectrique sont etudies. Les sections efficaces sont evaluees. Nous montrons comment l'introduction d'un indice de refraction, en habillant les photons, permet d'eliminer les divergences infra-rouges. La theorie semble compatible avec l'experience. (auteur)

  15. A review on the processing accuracy of two-photon polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xiaoqin; Hou, Yihong [School of Mechanical Science and Engineering, Jilin University, Changchun, 130022 (China); Lin, Jieqiong, E-mail: linjieqiong@mail.ccut.edu.cn [School of Electromechanical Engineering, Changchun University of Technology, Changchun, 130012 (China)

    2015-03-15

    Two-photon polymerization (TPP) is a powerful and potential technology to fabricate true three-dimensional (3D) micro/nanostructures of various materials with subdiffraction-limit resolution. And it has been applied to microoptics, electronics, communications, biomedicine, microfluidic devices, MEMS and metamaterials. These applications, such as microoptics and photon crystals, put forward rigorous requirements on the processing accuracy of TPP, including the dimensional accuracy, shape accuracy and surface roughness and the processing accuracy influences their performance, even invalidate them. In order to fabricate precise 3D micro/nanostructures, the factors influencing the processing accuracy need to be considered comprehensively and systematically. In this paper, we review the basis of TPP micro/nanofabrication, including mechanism of TPP, experimental set-up for TPP and scaling laws of resolution of TPP. Then, we discuss the factors influencing the processing accuracy. Finally, we summarize the methods reported lately to improve the processing accuracy from improving the resolution and changing spatial arrangement of voxels.

  16. A review on the processing accuracy of two-photon polymerization

    Directory of Open Access Journals (Sweden)

    Xiaoqin Zhou

    2015-03-01

    Full Text Available Two-photon polymerization (TPP is a powerful and potential technology to fabricate true three-dimensional (3D micro/nanostructures of various materials with subdiffraction-limit resolution. And it has been applied to microoptics, electronics, communications, biomedicine, microfluidic devices, MEMS and metamaterials. These applications, such as microoptics and photon crystals, put forward rigorous requirements on the processing accuracy of TPP, including the dimensional accuracy, shape accuracy and surface roughness and the processing accuracy influences their performance, even invalidate them. In order to fabricate precise 3D micro/nanostructures, the factors influencing the processing accuracy need to be considered comprehensively and systematically. In this paper, we review the basis of TPP micro/nanofabrication, including mechanism of TPP, experimental set-up for TPP and scaling laws of resolution of TPP. Then, we discuss the factors influencing the processing accuracy. Finally, we summarize the methods reported lately to improve the processing accuracy from improving the resolution and changing spatial arrangement of voxels.

  17. Measurement of exclusive two-photon processes with dilepton final states in pp collisions at the LHC

    CERN Document Server

    Forthomme, Laurent

    The unification of the electromagnetic and weak forces is a cornerstone of the standard theory of elementary particles and fundamental interactions. At the Large Hadron Collider the processes of pair production via fusion of two exchanged photons provide a unique laboratory both for testing the standard theory and for search of new phenomena in high-energy physics. In this thesis such a two-photon exclusive pair production in pp collisions has been studied experimentally, at two centre of mass energies using the data collected with the CMS experiment during LHC's Run-1. Thanks to large, effective photon fluxes and the outstanding performance of the CMS apparatus clean two-photon signal samples could be extracted. The novel track-based exclusivity selection was instrumental for making successful measurements in an extremely demanding LHC environment. In particular, the "reference" two-photon production of lepton pairs has been measured and investigated in detail, including extended phenomenological studies. A ...

  18. Parallel processing implementation for the coupled transport of photons and electrons using OpenMP

    Science.gov (United States)

    Doerner, Edgardo

    2016-05-01

    In this work the use of OpenMP to implement the parallel processing of the Monte Carlo (MC) simulation of the coupled transport for photons and electrons is presented. This implementation was carried out using a modified EGSnrc platform which enables the use of the Microsoft Visual Studio 2013 (VS2013) environment, together with the developing tools available in the Intel Parallel Studio XE 2015 (XE2015). The performance study of this new implementation was carried out in a desktop PC with a multi-core CPU, taking as a reference the performance of the original platform. The results were satisfactory, both in terms of scalability as parallelization efficiency.

  19. Exclusive two-photon processes: Tests of QCD at the amplitude level

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1992-07-01

    Exclusive two-photon processes at large momentum transfer, particularly Compton scattering γp→γp and its crossed-channel reactions γγ→ bar pp and bar pp→γγ, can provide definitive information on the bound-state distributions of quarks in hadrons at the amplitude level. Recent theoretical work has shown that QCD predictions based on the factorization of long and short distance physics are already applicable at momentum transfers of order of a few GeV

  20. An integrated nonlinear optical loop mirror in silicon photonics for all-optical signal processing

    Directory of Open Access Journals (Sweden)

    Zifei Wang

    2018-02-01

    Full Text Available The nonlinear optical loop mirror (NOLM has been studied for several decades and has attracted considerable attention for applications in high data rate optical communications and all-optical signal processing. The majority of NOLM research has focused on silica fiber-based implementations. While various fiber designs have been considered to increase the nonlinearity and manage dispersion, several meters to hundreds of meters of fiber are still required. On the other hand, there is increasing interest in developing photonic integrated circuits for realizing signal processing functions. In this paper, we realize the first-ever passive integrated NOLM in silicon photonics and demonstrate its application for all-optical signal processing. In particular, we show wavelength conversion of 10 Gb/s return-to-zero on-off keying (RZ-OOK signals over a wavelength range of 30 nm with error-free operation and a power penalty of less than 2.5 dB, we achieve error-free nonreturn to zero (NRZ-to-RZ modulation format conversion at 10 Gb/s also with a power penalty of less than 2.8 dB, and we obtain error-free all-optical time-division demultiplexing of a 40 Gb/s RZ-OOK data signal into its 10 Gb/s tributary channels with a maximum power penalty of 3.5 dB.

  1. Identifying opportunities to reduce the consumption of energy across mining and processing plants

    Energy Technology Data Exchange (ETDEWEB)

    Sterling, David; Johnson, Greg

    2010-09-15

    In addition to meeting Government Policy on Energy Efficiency Opportunities (EEOs), mining and mineral processing companies are increasing energy efficiency to reduce costs in the current financial conditions. One of the major issues with EEOs is the lack of data available on energy use, and more importantly the energy use linked to production data, that identify energy reduction opportunities. This paper looks at expanding the use of a Manufacturing Execution Systems by integrating with Energy Solutions. This will provide automatic, timely information, at a granularity that makes it easier to identify EEOs, reduce energy costs, and better predict energy use.

  2. Photonic efficiency of the photodegradation of paracetamol in water by the photo-Fenton process.

    Science.gov (United States)

    Yamal-Turbay, E; Ortega, E; Conte, L O; Graells, M; Mansilla, H D; Alfano, O M; Pérez-Moya, M

    2015-01-01

    An experimental study of the homogeneous Fenton and photo-Fenton degradation of 4-amidophenol (paracetamol, PCT) is presented. For all the operation conditions evaluated, PCT degradation is efficiently attained by both Fenton and photo-Fenton processes. Also, photonic efficiencies of PCT degradation and mineralization are determined under different experimental conditions, characterizing the influence of hydrogen peroxide (H2O2) and Fe(II) on both contaminant degradation and sample mineralization. The maximum photonic degradation efficiencies for 5 and 10 mg L(-1) Fe(II) were 3.9 (H2O2 = 189 mg L(-1)) and 5 (H2O2 = 378 mg L(-1)), respectively. For higher concentrations of oxidant, H2O2 acts as a "scavenger" radical, competing in pollutant degradation and reducing the reaction rate. Moreover, in order to quantify the consumption of the oxidizing agent, the specific consumption of the hydrogen peroxide was also evaluated. For all operating conditions of both hydrogen peroxide and Fe(II) concentration, the consumption values obtained for Fenton process were always higher than the corresponding values observed for photo-Fenton. This implies a less efficient use of the oxidizing agent for dark conditions.

  3. Process strategies for ultra-deep x-ray lithography at the Advanced Photon Source

    International Nuclear Information System (INIS)

    Mancini, D.C.; Moldovan, N.; Divan, R.; De Carlo, F.; Yaeger, J.

    2001-01-01

    For the past five years, we have been investigating and advancing processing capabilities for deep x-ray lithography (DXRL) using synchrotron radiation from a bending magnet at the Advanced Photon Source (APS), with an emphasis on ultra-deep structures (1mm to 1cm thick). The use of higher-energy x-rays has presented many challenges in developing optimal lithographic techniques for high-aspect ratio structures: mask requirements, resist preparation, exposure, development, and post-processing. Many problems are more severe for high-energy exposure of thicker films than for sub-millimeter structures and affect resolution, processing time, adhesion, damage, and residue. A number of strategies have been created to overcome the challenges and limitations of ultra-deep x-ray lithography (UDXRL), that have resulted in the current choices for mask, substrate, and process flow at the APS. We describe our current process strategies for UDXRL, how they address the challenges presented, and their current limitations. We note especially the importance of the process parameters for use of the positive tone resist PMMA for UDXRL, and compare to the use of negative tone resists such as SU-8 regarding throughput, resolution, adhesion, damage, and post-processing.

  4. Strategies to reduce mass and photons transfer limitations in heterogeneous photocatalytic processes: Hexavalent chromium reduction studies.

    Science.gov (United States)

    Marinho, Belisa A; Cristóvão, Raquel O; Djellabi, Ridha; Caseiro, Ana; Miranda, Sandra M; Loureiro, José M; Boaventura, Rui A R; Dias, Madalena M; Lopes, José Carlos B; Vilar, Vítor J P

    2018-07-01

    The current work presents different approaches to overcome mass and photon transfer limitations in heterogeneous photocatalytic processes applied to the reduction of hexavalent chromium to its trivalent form in the presence of a sacrificial agent. Two reactor designs were tested, a monolithic tubular photoreactor (MTP) and a micro-meso-structured photoreactor (NETmix), both presenting a high catalyst surface area per reaction liquid volume. In order to reduce photon transfer limitations, the tubular photoreactor was packed with transparent cellulose acetate monolithic structures (CAM) coated with the catalyst by a dip-coating method. For the NETmix reactor, a thin film of photocatalyst was uniformly deposited on the front glass slab (GS) or on the network of channels and chambers imprinted in the back stainless steel slab (SSS) using a spray system. The reaction rate for the NETmix photoreactor was evaluated for two illumination sources, solar light or UVA-LEDs, using the NETmix with the front glass slab or/and back stainless steel slab coated with TiO 2 -P25. The reusability of the photocatalytic films on the NETmix walls was also evaluated for three consecutive cycles using fresh Cr(VI) solutions. The catalyst reactivity in combination with the NETmix-SSS photoreactor is almost 70 times superior to one obtained with the MTP. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Cross sections for electron and photon processes required by electron-transport calculations

    International Nuclear Information System (INIS)

    Peek, J.M.

    1979-11-01

    Electron-transport calculations rely on a large collection of electron-atom and photon-atom cross-section data to represent the response characteristics of the target medium. These basic atomic-physics quantities, and certain qualities derived from them that are now commonly in use, are critically reviewed. Publications appearing after 1978 are not given consideration. Processes involving electron or photon energies less than 1 keV are ignored, while an attempt is made to exhaustively cover the remaining independent parameters and target possibilities. Cases for which data improvements can be made from existing information are identified. Ranges of parameters for which state-of-the-art data are not available are sought out, and recommendations for explicit measurements and/or calculations with presently available tools are presented. An attempt is made to identify the maturity of the atomic-physics data and to predict the possibilities for rapid changes in the quality of the data. Finally, weaknesses in the state-of-the-art atomic-physics data and in the conceptual usage of these data in the context of electron-transport theory are discussed. Brief attempts are made to weight the various aspects of these questions and to suggest possible remedies

  6. Design and Characterization of 64K Pixels Chips Working in Single Photon Processing Mode

    CERN Document Server

    Llopart Cudie, Xavier; Campbell, M

    2007-01-01

    Progress in CMOS technology and in fine pitch bump bonding has made possible the development of high granularity single photon counting detectors for X-ray imaging. This thesis studies the design and characterization of three pulse processing chips with 65536 square pixels of 55 µm x 55 µm designed in a commercial 0.25 µm 6-metal CMOS technology. The 3 chips share the same architecture and dimensions and are named Medipix2, Mpix2MXR20 and Timepix. The Medipix2 chip is a pixel detector readout chip consisting of 256 x 256 identical elements, each working in single photon counting mode for positive or negative input charge signals. The preamplifier feedback provides compensation for detector leakage current on a pixel by pixel basis. Two identical pulse height discriminators are used to define an energy window. Every event falling inside the energy window is counted with a 13 bit pseudo-random counter. The counter logic, based in a shift register, also behaves as the input/output register for the pixel. Each...

  7. Post-processing with linear optics for improving the quality of single-photon sources

    International Nuclear Information System (INIS)

    Berry, Dominic W; Scheel, Stefan; Myers, Casey R; Sanders, Barry C; Knight, Peter L; Laflamme, Raymond

    2004-01-01

    Triggered single-photon sources produce the vacuum state with non-negligible probability, but produce a much smaller multiphoton component. It is therefore reasonable to approximate the output of these photon sources as a mixture of the vacuum and single-photon states. We show that it is impossible to increase the probability for a single photon using linear optics and photodetection on fewer than four modes. This impossibility is due to the incoherence of the inputs; if the inputs were pure-state superpositions, it would be possible to obtain a perfect single-photon output. In the more general case, a chain of beam splitters can be used to increase the probability for a single photon, but at the expense of adding an additional multiphoton component. This improvement is robust against detector inefficiencies, but is degraded by distinguishable photons, dark counts or multiphoton components in the input

  8. One-photon two-electron processes in helium close to the double ionization threshold

    International Nuclear Information System (INIS)

    Bouri, C.

    2007-04-01

    This work presents a study of the 1 P 0 excited states of He that can be reached by absorption of a single photon carrying an energy close to the double ionization threshold (DIT) (79 eV). Above the DIT, these states are the double continuum states; below, they are the double excited states. These two types of states are tightly coupled to the single continuum states with or without excitation of the residual ion He + , owing to their degeneracy in energy. In a one-photon process, these states can only be formed owing to the electronic correlations in the system which must be well described to obtain quantitative good results. Our study is a part of the work which aims at a united description of all these doubly excited, ionized-excited, and double continuum states. We use the Hyperspherical R-Matrix with Semiclassical Outgoing Waves (HRM-SOW) method, initially dedicated to double photoionization studies. We extend it to extract information on the single continuum. This extension allows us to compute cross sections of single photoionization with or without excitation up to n 50 for an excess of 100 meV just above the double ionization threshold. A deep insight into this process is given by a partial waves analysis. The results obtained shed light on the key role of angular and radial correlations. The numerous data we obtain on double and single ionization allow us to establish a continuity relation between these two processes. We show that single ionization with an infinite excitation of the residual ion merges into double photoionization when the excess energy is redistributed between the two electrons. It appears that this relation is valid not only for low but also for high photon energies. Since the HRM-SOW can produce the integrated cross section for double photoionization with high accuracy in the low energy domain, we check the Wannier threshold law. The parameters extracted support strongly this threshold law, and are in good agreement with experimental

  9. Examining leisure event opportunities of Isle Royale National Park: bridging the gap between social process and spatial form

    Science.gov (United States)

    Chad D. Pierskalla; Dorothy H. Anderson; David W. Lime

    2000-01-01

    To manage various recreation opportunities, managers and planners must consider the spatial and temporal scale of social process when identifying opportunities on base maps. However, analyses of social process and spatial form are often treated as two distinct approaches--sociological and geographical approaches. A sociologist might control for spatial form by adopting...

  10. The entanglement of two moving atoms interacting with a single-mode field via a three-photon process

    International Nuclear Information System (INIS)

    Chao, Wu; Mao-Fa, Fang

    2010-01-01

    In this paper, the entanglement of two moving atoms induced by a single-mode field via a three-photon process is investigated. It is shown that the entanglement is dependent on the category of the field, the average photon number N, the number p of half-wave lengths of the field mode and the atomic initial state. Also, the sudden death and the sudden birth of the entanglement are detected in this model and the results show that the existence of the sudden death and the sudden birth depends on the parameter and the category of the mode field. In addition, the three-photon process is a higher order nonlinear process. (general)

  11. Development of photonic crystals using sol-gel process for high power laser applications

    International Nuclear Information System (INIS)

    Benoit, Florence

    2015-01-01

    Three-dimensional photonic crystals (PCs) are periodic materials with a modulated refractive index on a length scale close to the light wavelength. This optical property allows the preparation of specific optical components like highly reflective mirrors. Moreover, these structured materials might have a high laser-induced damage threshold (LIDT) in the sub-nanosecond range compared to multilayered dielectric mirrors. This property is obtained because only one high LIDT material (silica) is used. In this work, we present the development of 3D PCs with narrow-sized colloidal silica particles, prepared by sol-gel process and deposited with Langmuir-Blodgett technique. Different syntheses routes have been investigated and compared regarding the optical properties of the PCs. A numerical model based on an ideal opal network including defect influence is used to explain these experimental results. (author) [fr

  12. Optical components based on two-photon absorption process in functionalized polymers

    International Nuclear Information System (INIS)

    Klein, S.; Barsella, A.; Taupier, G.; Stortz, V.; Fort, A.; Dorkenoo, K.D.

    2006-01-01

    We report on the fabrication of basic elements needed in optical circuits in a photopolymerizable resin, using a two-photon absorption (TPA) process to perform a selective polymerization. By taking advantage of the high spatial selectivity of the TPA approach, we can control the value of the local index of refraction in the material and realize permanent optical pathways in the bulk of photopolymerizable matrices. The computer-controlled design of such pathways allows creating optical circuits. As an example of application, optical fibers separated by millimetric distances and placed in arbitrary positions have been connected with moderate losses. Moreover, active components, such as electro-optical Mach-Zehnder interferometers, can be fabricated using photopolymers functionalized with non-linear optical chromophores, in order to be integrated in micro-optical circuits

  13. Experimental quantum key distribution with simulated ground-to-satellite photon losses and processing limitations

    Science.gov (United States)

    Bourgoin, Jean-Philippe; Gigov, Nikolay; Higgins, Brendon L.; Yan, Zhizhong; Meyer-Scott, Evan; Khandani, Amir K.; Lütkenhaus, Norbert; Jennewein, Thomas

    2015-11-01

    Quantum key distribution (QKD) has the potential to improve communications security by offering cryptographic keys whose security relies on the fundamental properties of quantum physics. The use of a trusted quantum receiver on an orbiting satellite is the most practical near-term solution to the challenge of achieving long-distance (global-scale) QKD, currently limited to a few hundred kilometers on the ground. This scenario presents unique challenges, such as high photon losses and restricted classical data transmission and processing power due to the limitations of a typical satellite platform. Here we demonstrate the feasibility of such a system by implementing a QKD protocol, with optical transmission and full post-processing, in the high-loss regime using minimized computing hardware at the receiver. Employing weak coherent pulses with decoy states, we demonstrate the production of secure key bits at up to 56.5 dB of photon loss. We further illustrate the feasibility of a satellite uplink by generating a secure key while experimentally emulating the varying losses predicted for realistic low-Earth-orbit satellite passes at 600 km altitude. With a 76 MHz source and including finite-size analysis, we extract 3374 bits of a secure key from the best pass. We also illustrate the potential benefit of combining multiple passes together: while one suboptimal "upper-quartile" pass produces no finite-sized key with our source, the combination of three such passes allows us to extract 165 bits of a secure key. Alternatively, we find that by increasing the signal rate to 300 MHz it would be possible to extract 21 570 bits of a secure finite-sized key in just a single upper-quartile pass.

  14. Investigation of deep inelastic scattering processes involving large p$_{t}$ direct photons in the final state

    CERN Multimedia

    2002-01-01

    This experiment will investigate various aspects of photon-parton scattering and will be performed in the H2 beam of the SPS North Area with high intensity hadron beams up to 350 GeV/c. \\\\\\\\ a) The directly produced photon yield in deep inelastic hadron-hadron collisions. Large p$_{t}$ direct photons from hadronic interactions are presumably a result of a simple annihilation process of quarks and antiquarks or of a QCD-Compton process. The relative contribution of the two processes can be studied by using various incident beam projectiles $\\pi^{+}, \\pi^{-}, p$ and in the future $\\bar{p}$. \\\\\\\\b) The correlations between directly produced photons and their accompanying hadronic jets. We will examine events with a large p$_{t}$ direct photon for away-side jets. If jets are recognised their properties will be investigated. Differences between a gluon and a quark jet may become observable by comparing reactions where valence quark annihilations (away-side jet originates from a gluon) dominate over the QDC-Compton...

  15. Microwave photonics processing controlling the speed of light in semiconductor waveguides

    DEFF Research Database (Denmark)

    Xue, Weiqi; Chen, Yaohui; Sales, Salvador

    2009-01-01

    We review the theory of slow and fast light effect in semiconductor waveguides and potential applications of these effects in microwave photonic systems as RF phase shifters. Recent applications as microwave photonic filters is presented. Also, in the presentation more applications like optoelect......We review the theory of slow and fast light effect in semiconductor waveguides and potential applications of these effects in microwave photonic systems as RF phase shifters. Recent applications as microwave photonic filters is presented. Also, in the presentation more applications like...

  16. High index glass thin film processing for photonics and photovoltaic (PV) applications

    Science.gov (United States)

    Ogbuu, Okechukwu Anthony

    To favorably compete with fossil-fuel technology, the greatest challenge for thin film solar-cells is to improve efficiency and reduce material cost. Thickness scaling to thin film reduces material cost but affects the light absorption in the cells; therefore a concept that traps incident photons and increases its optical path length is needed to boost absorption in thin film solar cells. One approach is the integration of low symmetric gratings (LSG), using high index material, on either the front-side or backside of 30 um thin c-Si cells. In this study, Multicomponent TeO2--Bi2O 3--ZnO (TBZ) glass thin films were prepared using RF magnetron sputtering under different oxygen flow rates. The influences of oxygen flow rate on the structural and optical properties of the resulting thin films were investigated. The structural origin of the optical property variation was studied using X-ray diffraction, X-ray photoelectron spectroscopy, Raman Spectroscopy, and transmission electron microscopy. The results indicate that TBZ glass thin film is a suitable material for front side LSG material photovoltaic and photonics applications due to their amorphous nature, high refractive index (n > 2), broad band optical transparency window, low processing temperature. We developed a simple maskless method to pattern sputtered tellurite based glass thin films using unconventional agarose hydrogel mediated wet etching. Conventional wet etching process, while claiming low cost and high throughput, suffers from reproducibility and pattern fidelity issues due to the isotropic nature of wet chemical etching when applied to glasses and polymers. This method overcomes these challenges by using an agarose hydrogel stamp to mediate a conformal etching process. In our maskless method, agarose hydrogel stamps are patterned following a standard soft lithography and replica molding process from micropatterned masters and soaked in a chemical etchant. The micro-scale features on the stamp are

  17. Clinical Natural Language Processing in languages other than English: opportunities and challenges.

    Science.gov (United States)

    Névéol, Aurélie; Dalianis, Hercules; Velupillai, Sumithra; Savova, Guergana; Zweigenbaum, Pierre

    2018-03-30

    Natural language processing applied to clinical text or aimed at a clinical outcome has been thriving in recent years. This paper offers the first broad overview of clinical Natural Language Processing (NLP) for languages other than English. Recent studies are summarized to offer insights and outline opportunities in this area. We envision three groups of intended readers: (1) NLP researchers leveraging experience gained in other languages, (2) NLP researchers faced with establishing clinical text processing in a language other than English, and (3) clinical informatics researchers and practitioners looking for resources in their languages in order to apply NLP techniques and tools to clinical practice and/or investigation. We review work in clinical NLP in languages other than English. We classify these studies into three groups: (i) studies describing the development of new NLP systems or components de novo, (ii) studies describing the adaptation of NLP architectures developed for English to another language, and (iii) studies focusing on a particular clinical application. We show the advantages and drawbacks of each method, and highlight the appropriate application context. Finally, we identify major challenges and opportunities that will affect the impact of NLP on clinical practice and public health studies in a context that encompasses English as well as other languages.

  18. Opportunities and barriers for OHS consultants in a technological change process at a client enterprise

    DEFF Research Database (Denmark)

    Broberg, Ole; Hermund, Ingelise

    2003-01-01

    In a case study of the design of inside finish and equipment of a new factory building the opportunities and barriers for OHS consultants in integrating work environment aspects are discussed. The work prac-tice of OHS consultants is studied in terms of theories from the sociology of technology....... Taking initially the role as experts the consultants in a reflective process change their strategy towards establishing a net-work in the client enterprise, going beyond the joint safety organization and more directly to the designers of new buildings and equipment. This indicates that the conditions...

  19. 40-Gb/s all-optical processing systems using hybrid photonic integration technology

    DEFF Research Database (Denmark)

    Kehayas, E.; Tsiokos, D.I.; Bakopoulos, P.

    2006-01-01

    the potential that all-optical technology can find application in future data-centric networks with efficient and dynamic bandwidth utilization. This paper also reports on the latest photonic integration breakthroughs as a potential migration path for reducing fabrication cost by developing photonic systems...

  20. On the γ-photon detection processes and the statistics of radiation

    International Nuclear Information System (INIS)

    Bertolotti, M.; Sibilia, C.

    1977-01-01

    The problem of detection of γ-photons is treated in the cases of photoelectric and Compton effects. In both cases the probability of detecting a γ-photon is found proportional to the first-order correlation function of the e.m. field. The statistical properties of the γ-radiation can therefore be determined through the methods developed in quantum optics

  1. Recent advances in organic one-dimensional composite materials: design, construction, and photonic elements for information processing.

    Science.gov (United States)

    Yan, Yongli; Zhang, Chuang; Yao, Jiannian; Zhao, Yong Sheng

    2013-07-19

    Many recent activities in the use of one-dimensional nanostructures as photonic elements for optical information processing are explained by huge advantages that photonic circuits possess over traditional silicon-based electronic ones in bandwidth, heat dissipation, and resistance to electromagnetic wave interference. Organic materials are a promising candidate to support these optical-related applications, as they combine the properties of plastics with broad spectral tunability, high optical cross-section, easy fabrication, as well as low cost. Their outstanding compatibility allows organic composite structures which are made of two or more kinds of materials combined together, showing great superiority to single-component materials due to the introduced interactions among multiple constituents, such as energy transfer, electron transfer, exciton coupling, etc. The easy processability of organic 1D crystalline heterostructures enables a fine topological control of both composition and geometry, which offsets the intrinsic deficiencies of individual material. At the same time, the strong exciton-photon coupling and exciton-exciton interaction impart the excellent confinement of photons in organic microstructures, thus light can be manipulated according to our intention to realize specific functions. These collective properties indicate a potential utility of organic heterogeneous material for miniaturized photonic circuitry. Herein, focus is given on recent advances of 1D organic crystalline heterostructures, with special emphasis on the novel design, controllable construction, diverse performance, as well as wide applications in isolated photonic elements for integration. It is proposed that the highly coupled, hybrid optical networks would be an important material basis towards the creation of on-chip optical information processing. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Arrays of surface-normal electroabsorption modulators for the generation and signal processing of microwave photonics signals

    NARCIS (Netherlands)

    Noharet, Bertrand; Wang, Qin; Platt, Duncan; Junique, Stéphane; Marpaung, D.A.I.; Roeloffzen, C.G.H.

    2011-01-01

    The development of an array of 16 surface-normal electroabsorption modulators operating at 1550nm is presented. The modulator array is dedicated to the generation and processing of microwave photonics signals, targeting a modulation bandwidth in excess of 5GHz. The hybrid integration of the

  3. Proceedings of the meeting on the planning of the computer control and data processing system in the photon factory project

    International Nuclear Information System (INIS)

    Ando, Masami; Ohta, Toshiaki

    1978-07-01

    In the photon factory for synchrotron radiation experiments, a computer control and data processing system is required for efficient utilization of the factory. Reports made in the meeting oriented as above are presented individually, reflecting various aspects of joint-use computer system and its technological advances. (Mori, K.)

  4. Singular value decomposition for photon-processing nuclear imaging systems and applications for reconstruction and computing null functions

    Science.gov (United States)

    Jha, Abhinav K.; Barrett, Harrison H.; Frey, Eric C.; Clarkson, Eric; Caucci, Luca; Kupinski, Matthew A.

    2015-09-01

    Recent advances in technology are enabling a new class of nuclear imaging systems consisting of detectors that use real-time maximum-likelihood (ML) methods to estimate the interaction position, deposited energy, and other attributes of each photon-interaction event and store these attributes in a list format. This class of systems, which we refer to as photon-processing (PP) nuclear imaging systems, can be described by a fundamentally different mathematical imaging operator that allows processing of the continuous-valued photon attributes on a per-photon basis. Unlike conventional photon-counting (PC) systems that bin the data into images, PP systems do not have any binning-related information loss. Mathematically, while PC systems have an infinite-dimensional null space due to dimensionality considerations, PP systems do not necessarily suffer from this issue. Therefore, PP systems have the potential to provide improved performance in comparison to PC systems. To study these advantages, we propose a framework to perform the singular-value decomposition (SVD) of the PP imaging operator. We use this framework to perform the SVD of operators that describe a general two-dimensional (2D) planar linear shift-invariant (LSIV) PP system and a hypothetical continuously rotating 2D single-photon emission computed tomography (SPECT) PP system. We then discuss two applications of the SVD framework. The first application is to decompose the object being imaged by the PP imaging system into measurement and null components. We compare these components to the measurement and null components obtained with PC systems. In the process, we also present a procedure to compute the null functions for a PC system. The second application is designing analytical reconstruction algorithms for PP systems. The proposed analytical approach exploits the fact that PP systems acquire data in a continuous domain to estimate a continuous object function. The approach is parallelizable and

  5. Singular value decomposition for photon-processing nuclear imaging systems and applications for reconstruction and computing null functions.

    Science.gov (United States)

    Jha, Abhinav K; Barrett, Harrison H; Frey, Eric C; Clarkson, Eric; Caucci, Luca; Kupinski, Matthew A

    2015-09-21

    Recent advances in technology are enabling a new class of nuclear imaging systems consisting of detectors that use real-time maximum-likelihood (ML) methods to estimate the interaction position, deposited energy, and other attributes of each photon-interaction event and store these attributes in a list format. This class of systems, which we refer to as photon-processing (PP) nuclear imaging systems, can be described by a fundamentally different mathematical imaging operator that allows processing of the continuous-valued photon attributes on a per-photon basis. Unlike conventional photon-counting (PC) systems that bin the data into images, PP systems do not have any binning-related information loss. Mathematically, while PC systems have an infinite-dimensional null space due to dimensionality considerations, PP systems do not necessarily suffer from this issue. Therefore, PP systems have the potential to provide improved performance in comparison to PC systems. To study these advantages, we propose a framework to perform the singular-value decomposition (SVD) of the PP imaging operator. We use this framework to perform the SVD of operators that describe a general two-dimensional (2D) planar linear shift-invariant (LSIV) PP system and a hypothetical continuously rotating 2D single-photon emission computed tomography (SPECT) PP system. We then discuss two applications of the SVD framework. The first application is to decompose the object being imaged by the PP imaging system into measurement and null components. We compare these components to the measurement and null components obtained with PC systems. In the process, we also present a procedure to compute the null functions for a PC system. The second application is designing analytical reconstruction algorithms for PP systems. The proposed analytical approach exploits the fact that PP systems acquire data in a continuous domain to estimate a continuous object function. The approach is parallelizable and

  6. Mapping of the atomic hydrogen density in combustion processes at atmospheric pressure by two-photon polarization spectroscopy

    International Nuclear Information System (INIS)

    Steiger, A.; Gruetzmacher, K.; Steiger, M.; Gonzalo, A.B.; Rosa, M.I. de la

    2001-01-01

    With laser spectroscopic techniques used so far, quantitative measurements of atomic number densities in flames and other combustion processes at atmospheric pressure yield no satisfying results because high quenching rates remarkably reduce the signal size and the results suffer from large uncertainties. Whereas, two-photon polarization spectroscopy is not limited by quenching, as the polarization signal is a direct measure of the two-photon absorption. This sensitive laser technique with high spatial and temporal resolution has been applied to determine absolute number densities and the kinetic temperatures of atomic hydrogen in flames for the first time. The great potential of this method of measurement comes into its own only in conjunction with laser radiation of highest possible spectral quality, i.e. single-frequency ns-pulses with peak irradiance of up to 1 GW/cm 2 tunable around 243 nm for 1S-2S two-photon transition of atomic hydrogen

  7. Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    For the application of photon to industrial technologies, in particular, a hard photon technology was surveyed which uses photon beams of 0.1-200nm in wavelength. Its features such as selective atom reaction, dense inner shell excitation and spacial high resolution by quantum energy are expected to provide innovative techniques for various field such as fine machining, material synthesis and advanced inspection technology. This wavelength region has been hardly utilized for industrial fields because of poor development of suitable photon sources and optical devices. The developmental meaning, usable time and issue of a hard photon reduction lithography were surveyed as lithography in ultra-fine region below 0.1{mu}m. On hard photon analysis/evaluation technology, the industrial use of analysis, measurement and evaluation technologies by micro-beam was viewed, and optimum photon sources and optical systems were surveyed. Prediction of surface and surface layer modification by inner shell excitation, the future trend of this process and development of a vacuum ultraviolet light source were also surveyed. 383 refs., 153 figs., 17 tabs.

  8. Downstream gas processing opportunities arising from the 1990's quest for a quality environment

    International Nuclear Information System (INIS)

    Geren, P.M.

    1992-01-01

    Over the last several years the former wart on your favorite daughter's nose (gas liquids processing) has become a most cherished body part, to paraphrase 1991 remarks of a U.S. gas processing leader. The dramatic recent spreads between liquids prices and the cost of feedstock natural gas have provided spectacular performance for processors. However, market prices for liquids will probably track petroleum. One day soon natural gas's inherent value will rise to parity with petroleum on a heating value basis. As petroleum demands will probably be flat in the foreseeable term, and natural gas prices will rise, something must be done to preserve gas processors' margins. Radical change in the formulation of U.S. gasoline presents many opportunities for gas processor to diversify into synthesis of upgraded derivatives of natural gas and liquids, which derivatives have high value-added characteristics. Issues relating to the selection of derivatives, the required technology, and capital project considerations are discussed in this paper

  9. Biexcitonic photocurrent induced by two-photon process at a telecommunication band

    International Nuclear Information System (INIS)

    Kodera, Tetsuo; Miyazawa, Toshiyuki; Kumagai, Naoto; Watanabe, Katsuyuki; Suzuki, Ayako; Takagi, Hiroyuki; Nakaoka, Toshihiro; Arakawa, Yasuhiko

    2009-01-01

    We report on photocurrent (PC) measurements of biexciton in a single self-assembled InAs quantum dot (QD) at a telecommunication wavelength of 1.3μm. We use shadow mask technique on an n-i Schottky photodiode structure with QDs to excite a single QD resonantly. Coherent pulse excitation is realized in two types of setups utilizing (i) an optical parametric oscillator and (ii) a stable semiconductor laser diode. In both setups we observe the biexcitonic PC peaks induced by a coherent two-photon process. Especially in the latter setups, the narrower pulse linewidth in energy provides a clearer biexcitonic PC peak because of reduced unwanted excitation. We estimate the binding energy ΔE B of our telecom-band biexciton to be 0.9 meV from the splitting between excitonic and biexcitonic resonances. The result suggests our telecom-band exciton-biexciton system is a good candidate for the building block of fiber-based controlled-rotation quantum logic operation. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Hadron production in photon-photon collisions

    International Nuclear Information System (INIS)

    Pandita, P.N.; Singh, Y.

    1976-01-01

    We analyze deep-inelastic photon-photon collisions via the two-photon mechanism in electron-positron (-electron) colliding beams in a form especially suitable for experimental analysis. It is shown that by a helicity analysis similar to that used in electroproduction experiments, we can separate five of the eight structure functions describing the process γ* + γ* → hadrons. The helicity cross sections for this process and for the process with one real photon (inelastic electron-photon scattering) are related to structure functions, and are evaluated using quark light-cone algebra. There are anomalous contributions to the structure functions for the inelastic electron-photon scattering which arise both in parton as well as generalized vector-meson-dominance models. This suggests a connection between these two types of models for photon-photon scattering. Further, we use vector-meson dominance to construct a sum rule for sigma/sub gamma//sub gamma/ /sub arrow-right/ from which it is estimated that roughly 20% of the cross section should be built up from higher-mass vector states. Using a spectral representation for the total transverse cross section, and the ''aligned-jet'' vector-dominance model we achieve a connection, via a ''correspondence principle,'' with the parton model for the hadron multiplicities in photon-photon collisions. We also comment on inclusive pion multiplicities and the approach to scaling for photon-photon processes in the light-cone algebra

  11. Improved Microwave Photonic Links via Receive-Side Nonlinear Signal Processing, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to significantly enhance the state-of-the-art of photonically-assisted microwave measurement and distribution systems by incorporating a highly efficient...

  12. Optical beam induced current measurements based on two-photon absorption process in 4H-SiC bipolar diodes

    Energy Technology Data Exchange (ETDEWEB)

    Hamad, H.; Raynaud, C.; Bevilacqua, P.; Tournier, D.; Planson, D. [Ampère Laboratory - UMR 5005, 21, Avenue Jean Capelle, 69621 Villeurbanne Cedex (France); Vergne, B. [Franco-Allemand Institute of Saint-Louis ISL, 5, Rue du Général Cassagnou, 68300 Saint-Louis (France)

    2014-02-24

    Using a pulsed green laser with a wavelength of 532 nm, a duration pulse of ∼1 ns, and a mean power varying between 1 and 100 mW, induced photocurrents have been measured in 4H-SiC bipolar diodes. Considering the photon energy (2.33 eV) and the bandgap of 4H-SiC (3.2 eV), the generation of electron-hole pair by the conventional single photon absorption process should be negligible. The intensity of the measured photocurrents depends quadratically on the power beam intensity. This clearly shows that they are generated using two-photon absorption process. As in conventional OBIC (Optical Beam Induced Current), the measurements give an image of the electric field distribution in the structure under test, and the minority carrier lifetime can be extracted from the decrease of the photocurrent at the edge of the structure. The extracted minority carrier lifetime of 210 ns is consistent with results obtained in case of single photon absorption.

  13. Optical beam induced current measurements based on two-photon absorption process in 4H-SiC bipolar diodes

    International Nuclear Information System (INIS)

    Hamad, H.; Raynaud, C.; Bevilacqua, P.; Tournier, D.; Planson, D.; Vergne, B.

    2014-01-01

    Using a pulsed green laser with a wavelength of 532 nm, a duration pulse of ∼1 ns, and a mean power varying between 1 and 100 mW, induced photocurrents have been measured in 4H-SiC bipolar diodes. Considering the photon energy (2.33 eV) and the bandgap of 4H-SiC (3.2 eV), the generation of electron-hole pair by the conventional single photon absorption process should be negligible. The intensity of the measured photocurrents depends quadratically on the power beam intensity. This clearly shows that they are generated using two-photon absorption process. As in conventional OBIC (Optical Beam Induced Current), the measurements give an image of the electric field distribution in the structure under test, and the minority carrier lifetime can be extracted from the decrease of the photocurrent at the edge of the structure. The extracted minority carrier lifetime of 210 ns is consistent with results obtained in case of single photon absorption

  14. Full report: Assessment and opportunity identification of energy efficient pollution prevention technologies and processes

    Energy Technology Data Exchange (ETDEWEB)

    1994-11-01

    US industry produces about 12 billion tons of waste a year, or two-thirds of the waste generated in the US. The costs of handling and disposing of these wastes are significant, estimated to be between $25 and $43 billion in 1991, and represent an increase of 66% since 1986. US industry also uses about one-third of all energy consumed in the nation, which adds to the environmental burden. Industrial wastes affect the environmental well-being of the nation and, because of their growing costs, the competitive abilities of US industry. As part of a national effort to reduce industrial wastes, the US Congress passed the Energy Policy Act (EPAct, P.L. 102-486). Section 2108, subsections (b) and (c), of EPAct requires the Department of Energy (DOE) to identify opportunities to demonstrate energy efficient pollution prevention technologies and processes; to assess their availability and the energy, environmental, and cost effects of such technologies; and to report the results. Work for this report clearly pointed to two things, that there is insufficient data on wastes and that there is great breadth and diversity in the US industrial sector. This report identifies: information currently available on industrial sector waste streams, opportunities for demonstration of energy efficient pollution prevention technologies in two industries that produce significant amounts of waste--chemicals and petroleum, characteristics of waste reducing and energy saving technologies identifiable in the public literature, and potential barriers to adoption of waste reducing technologies by industry.

  15. FY 1998 achievement report on the photon measuring/processing technology (R and D of the photon measuring/processing technology); 1998 nendo foton keisoku kako gijutsu seika hokokusho. Foton keisoku kako gijutsu no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    In this project, the survey/arrangement were made of the trend of the recent technology such as photon (laser) measuring/processing/generation and a possibility of adopting the photon technology to the field except measuring/processing, to clarify technical subjects for establishing/commercializing the photon technology. Also for the purpose of reducing the energy cost by improving the performance of laser processing device, prolonging the life and reducing the operational cost, the development of the following were carried out: (1) high efficiency laser processing device. (2) high conversion efficiency laser diode. In (1), a laser generating device with Yb:YAG crystal as oscillating medium was trially manufactured, and the power of 35W and optical-optical conversion efficiency of 7.1% were obtained. A comparison was also made between Yb:YAG laser and Nd:YAG laser, and made it clear that as the industrial use high power laser, Nd:YAG laser has the advantage over the other. In (2), the development was made of technology for simultaneous uniform growth of more than one LD crystal wafers with high conversion efficiency and technology for evaluation. Namely, the high uniformity crystal wafer with variations among wafers of {+-}4% was obtained using the introduced high efficiency crystal growth device and high efficiency thin film evaluation device. (NEDO)

  16. Analysis of InP-based single photon avalanche diodes based on a single recess-etching process

    Science.gov (United States)

    Lee, Kiwon

    2018-04-01

    Effects of the different etching techniques have been investigated by analyzing electrical and optical characteristics of two-types of single-diffused single photon avalanche diodes (SPADs). The fabricated two-types of SPADs have no diffusion depth variation by using a single diffusion process at the same time. The dry-etched SPADs show higher temperature dependence of a breakdown voltage, larger dark-count-rate (DCR), and lower photon-detection-efficiency (PDE) than those of the wet-etched SPADs due to plasma-induced damage of dry-etching process. The results show that the dry etching damages can more significantly affect the performance of the SPADs based on a single recess-etching process.

  17. The scientific study of inspiration in the creative process: Challenges and opportunities

    Directory of Open Access Journals (Sweden)

    Victoria C. Oleynick

    2014-06-01

    Full Text Available Inspiration is a motivational state that compels individuals to bring ideas into fruition. Creators have long argued that inspiration is important to the creative process, but until recently, scientists have not investigated this claim. In this article, we review challenges to the study of creative inspiration, as well as solutions to these challenges afforded by theoretical and empirical work on inspiration over the past decade. First, we discuss the problem of definitional ambiguity, which has been addressed through an integrative process of construct conceptualization. Second, we discuss the challenge of how to operationalize inspiration. This challenge has been overcome by the development and validation of the Inspiration Scale, which may be used to assess trait or state inspiration. Third, we address ambiguity regarding how inspiration differs from related concepts (creativity, insight, positive affect by discussing discriminant validity. Next, we discuss the preconception that inspiration is less important than perspiration (effort, and we review empirical evidence that inspiration and effort both play important—but different—roles in the creative process. Finally, with many challenges overcome, we argue that the foundation is now set for a new generation of research focused on neural underpinnings. We discuss potential challenges to and opportunities for the neuroscientific study of inspiration. A better understanding of the biological basis of inspiration will illuminate the process through which creative ideas fire the soul, such that individuals are compelled to transform ideas into products and solutions that may benefit society.

  18. Opportunities for low-grade heat recovery in the UK food processing industry

    International Nuclear Information System (INIS)

    Law, Richard; Harvey, Adam; Reay, David

    2013-01-01

    Energy efficiency in the process industry is becoming an increasingly important issue due to the rising costs of both electricity and fossil fuel resources, as well as the tough targets for the reduction in greenhouse gas emissions outlined in the Climate Change Act 2008. Utilisation of waste heat sources is key to improving industrial energy efficiency, with an estimated 11.4 TWh of recoverable heat being wasted each year, a quarter of which is from the food and drinks processing sector. This paper examines the low-grade waste heat sources common to the food and drinks processing sector and the various opportunities for the use of this heat. A review of the best available technologies for recovery of waste heat is provided, ranging from heat transfer between source and sink, to novel technologies for the generation of electricity and refrigeration. Generally, the most economic option for waste heat recovery is heat exchange between nearby/same process source and sink, with a number of well-developed heat exchangers widely available for purchase. More novel options, such as the use of organic Rankine cycles for electricity generation prove to be less economical due to high capital outlays. However, with additional funding provision for demonstration of such projects and development of modular units, such technologies would become more common

  19. Photonics-based real-time ultra-high-range-resolution radar with broadband signal generation and processing.

    Science.gov (United States)

    Zhang, Fangzheng; Guo, Qingshui; Pan, Shilong

    2017-10-23

    Real-time and high-resolution target detection is highly desirable in modern radar applications. Electronic techniques have encountered grave difficulties in the development of such radars, which strictly rely on a large instantaneous bandwidth. In this article, a photonics-based real-time high-range-resolution radar is proposed with optical generation and processing of broadband linear frequency modulation (LFM) signals. A broadband LFM signal is generated in the transmitter by photonic frequency quadrupling, and the received echo is de-chirped to a low frequency signal by photonic frequency mixing. The system can operate at a high frequency and a large bandwidth while enabling real-time processing by low-speed analog-to-digital conversion and digital signal processing. A conceptual radar is established. Real-time processing of an 8-GHz LFM signal is achieved with a sampling rate of 500 MSa/s. Accurate distance measurement is implemented with a maximum error of 4 mm within a range of ~3.5 meters. Detection of two targets is demonstrated with a range-resolution as high as 1.875 cm. We believe the proposed radar architecture is a reliable solution to overcome the limitations of current radar on operation bandwidth and processing speed, and it is hopefully to be used in future radars for real-time and high-resolution target detection and imaging.

  20. Opportunities and barriers for OHS consultants in a technological change process at a client enterprise

    DEFF Research Database (Denmark)

    Hermund, Ingelise; Broberg, Ole

    2003-01-01

    . Taking initially the role as experts the consultants in a reflective process change their strategy towards establishing a net-work in the client enterprise, going beyond the joint safety organization and more directly to the designers of new buildings and equipment. This indicates that the conditions......In a case study of the design of inside finish and equipment of a new factory building the opportunities and barriers for OHS consultants in integrating work environment aspects are discussed. The work prac-tice of OHS consultants is studied in terms of theories from the sociology of technology...... for the work of OHS consultants can be challenged and changed if the consultants are able to take the role of a political reflective navigator....

  1. Photon-photon interactions

    International Nuclear Information System (INIS)

    Gilman, F.J.

    1980-01-01

    A brief summary of the present status of photon-photon interactions is presented. Stress is placed on the use of two-photon collisions to test present ideas on the quark constituents of hadrons and on the theory of strong interactions

  2. The Regulatory Review Process in South Africa: Challenges and Opportunities for a New Improved System.

    Science.gov (United States)

    Keyter, Andrea; Gouws, Joey; Salek, Sam; Walker, Stuart

    2018-01-01

    The aims of this study were to assess the regulatory review process in South Africa from 2015 to 2017, identify the key milestones and timelines; evaluate the effectiveness of measures to ensure consistency, transparency, timeliness, and predictability in the review process; and to provide recommendations for enhanced regulatory practices. A questionnaire was completed by the Medicines Control Council (MCC) to describe the organization of the authority, record key milestones and timelines in the review process and to identify good review practices (GRevPs). Currently, the MCC conducts a full assessment of quality, efficacy, and safety data in the review of all applications. The overall regulatory median approval time decreased by 14% in 2017 (1411 calendar days) compared with that of 2016, despite the 27% increase in the number of applications. However, the MCC has no target for overall approval time of new active substance applications and no targets for key review milestones. Guidelines, standard operating procedures, and review templates are in place, while the formal implementation of GRevPs and the application of an electronic document management system are planned for the near future. As the MCC transitions to the newly established South Africa Health Products Regulatory Authority, it would be crucial for the authority to recognize the opportunities for an enhanced regulatory review and should consider models such as abridged assessment, which encompass elements of risk stratification and reliance. It is hoped that resource constraints may then be alleviated and capacity developed to meet target timelines.

  3. Chemical control of channel interference in two-photon absorption processes.

    Science.gov (United States)

    Alam, Md Mehboob; Chattopadhyaya, Mausumi; Chakrabarti, Swapan; Ruud, Kenneth

    2014-05-20

    The two-photon absorption (TPA) process is the simplest and hence the most studied nonlinear optical phenomenon, and various aspects of this process have been explored in the past few decades, experimentally as well as theoretically. Previous investigations have shown that the two-photon (TP) activity of a molecular system can be tuned, and at present, performance-tailored TP active materials are easy to develop by monitoring factors such as length of conjugation, dimensionality of charge-transfer network, strength of donor-acceptor groups, polarity of solvents, self-aggregation, H-bonding, and micellar encapsulation to mention but a few. One of the most intriguing phenomena affecting the TP activity of a molecule is channel interference. The phrase "channel interference" implies that if the TP transition from one electronic state to another involves more than one optical pathway or channel, characterized by the corresponding transition dipole moment (TDM) vectors, the channels may interfere with each other depending upon the angles between the TDM vectors and hence can either increase (constructive interference) or decrease (destructive interference) the overall TP activity of a system to a significant extent. This phenomenon was first pointed out by Cronstrand, Luo, and Ågren [Chem. Phys. Lett. 2002, 352, 262-269] in two-dimensional systems (i.e., only involving two components of the transition moment vectors). For three-dimensional molecules, an extended version of this idea was required. In order to fill this gap, we developed a generalized model for describing and exploring channel interference, valid for systems of any dimensionality. We have in particular applied it to through-bond (TB) and through-space (TS) charge-transfer systems both in gas phase and in solvents with different polarities. In this Account, we will, in addition to briefly describing the concept of channel interference, discuss two key findings of our recent work: (1) how to control the

  4. Opportunities and Challenges in Application of Forward Osmosis in Food Processing.

    Science.gov (United States)

    Rastogi, Navin K

    2016-01-01

    Food processing and preservation technologies must maintain the fresh-like characteristics of food while providing an acceptable and convenient shelf life as well as assuring safety and nutritional value. Besides, the consumers' demand for the highest quality convenience foods in terms of natural flavor and taste, free from additives and preservatives necessitated the development of a number of membrane-based non-thermal approaches to the concentration of liquid foods, of which forward osmosis has proven to be the most valuable one. A series of recent publications in scientific journals have demonstrated novel and diverse uses of this technology for food processing, desalination, pharmaceuticals as well as for power generation. Its novel features, which include the concentration of liquid foods at ambient temperature and pressure without significant fouling of membrane, made the technology commercially attractive. This review aims to identify the opportunities and challenges associated with this technology. At the same time, it presents a comprehensive account of recent advances in forward osmosis technology as related to the major issues of concern in its rapidly growing applications in food processing such as concentration of fruit and vegetable juices (grape, pineapple, red raspberry, orange, and tomato juice and red radish juice) and natural food colorants (anthocyanin and betalains extracts). Several vibrant and vital issues such as recent developments in the forward osmosis membrane and concentration polarization aspects have been also addressed. The asymmetric membrane used for forward osmosis poses newer challenges to account both external and internal concentration polarization leading to significant reduction in flux. The recent advances and developments in forward osmosis membrane processes, mechanism of water transport, characteristics of draw solution and membranes as well as applications of forward osmosis in food processing have been discussed.

  5. Capitalizing on new opportunities in Canada's emerging midstream : processing, transportation, marketing, NGL, storage : proceedings of a Canadian Institute conference

    International Nuclear Information System (INIS)

    1999-01-01

    Text or speaking notes used at a conference to examine the challenges and opportunities facing Canada's midstream petroleum and natural gas industry are contained in this volume. A total of eight 8 papers were presented, focusing on the wide range of business opportunities that do not fit into the core functions of the upstream business (exploration and production), or into the core functions of the downstream business (distribution and retail marketing). One of the biggest opportunities lies in the development of storage facilities for the natural gas industry. Other aspects of the midstream business addressed included processing, transportation, marketing, and natural gas liquids. tabs., figs

  6. A high-speed tunable beam splitter for feed-forward photonic quantum information processing.

    Science.gov (United States)

    Ma, Xiao-Song; Zotter, Stefan; Tetik, Nuray; Qarry, Angie; Jennewein, Thomas; Zeilinger, Anton

    2011-11-07

    We realize quantum gates for path qubits with a high-speed, polarization-independent and tunable beam splitter. Two electro-optical modulators act in a Mach-Zehnder interferometer as high-speed phase shifters and rapidly tune its splitting ratio. We test its performance with heralded single photons, observing a polarization-independent interference contrast above 95%. The switching time is about 5.6 ns, and a maximal repetition rate is 2.5 MHz. We demonstrate tunable feed-forward operations of a single-qubit gate of path-encoded qubits and a two-qubit gate via measurement-induced interaction between two photons.

  7. Production and processing of fuel by the forest industry - opportunities and conditions

    International Nuclear Information System (INIS)

    Magnusson, L.

    1991-01-01

    The purpose of this study was to illustrate the opportunities for the forest industry to establish a system of handling and processing biofuels in conjunction with their existing activities, and which would supply a future market for biofuels in, for example, electricity generation. The sawmills report that it is difficult today to find a market for fuel products, especially for sawmills at greater distances from larger biofuel-consuming plants. The sawmills show great interest in cogeneration in their own plants, but report difficulties in achieving profitability. The main problem is reported to be that the price of the surplus electricity delivered to the grid is too low, but also that the electricity prices today are so low that it is difficult to justify even generating electricity for the mill's own use. There is an interest in the paper and pulp industry for integrated methods and production of biofuels since the part-tree methods used, at least in some parts of Sweden, are considered to contribute also to an increase in the availability of pulp wood to the industry. A fundamental viewpoint is, however, that the plants are built for the primary purpose of producing pulp or paper. It is unlikely that the industry would give priority to investments for production of a new secondary product in the form of fuel products, particularly when the conditions today imply that there are few possibilities to achieve any particular profitability. The most probable solution is that the fuel is processed outside the industry by other parties, e.g., the forest divisions. In the long term, increased efficiency in the processes may lead to a primary heat surplus which could be used to produce processed fuels

  8. FY 1999 report on the results of the research and development project for the photon-aided instrumentation and processing technologies. R and D of the photon-aided instrumentation and processing technologies; 1999 nendo photon keisoku kako gijutsu seika hokokusho. Photon keisoku kako gijutsu no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Described herein are the FY 1999 results of development of the photon-aided instrumentation and processing technologies. The photon technologies will be widely applicable to various industrial areas, e.g., medical, diagnostic, communication, transmission and chemical areas, in addition to instrumentation and processing, and the FY 1999 project is directed to the survey and analysis of the information, and prediction of their effects. The high-sensitivity light-receiving elements enlarged up to 5mm diameter (effective area) are developed, based on the technologies to grow the thin films using an MOVPE (metal-organic vapor-phase epitaxy) device and the results of development of the infrared ray-receiving InGaAs photodiode sensitive in a 2.5 to 2.7{mu}m wavelength range. The surface roughness of 0.4nmRMS is achieved by the bowl feed liquid polishing method, to develop the processing technologies for high-precision substrates for optical mirrors. The results are used to develop the prototype X-ray mirrors with surface accuracy of {lambda}/10 to {lambda}/20 and roughness of 0.3 to 0.5nmRMS. In the development of the technologies for the light sources which can sufficiently supply photons for exciting semiconductor lasers, the technologies are developed to efficiently converge the laser beams. Also developed are the apparatus which can converge the beams to a diameter of around 0.6mm, and the apparatus which uses optical fibers to evaluate the beam diameter. (NEDO)

  9. International Conference on Applications of Photonic Technology, Communications, Sensing, Materials and Signal Processing

    CERN Document Server

    Lessard, Roger; ICAPT '96; Applications of photonic technology 2

    1997-01-01

    This book presents a current review ofphotonic technologies and their applications. The papers published in this book are extended versions of the papers presented at the Inter­ national Conference on Applications ofPhotonic Technology (ICAPT'96) held in Montreal, Canada, on July 29 to August 1, 1996. The theme of this event was "Closing the Gap Between Theory, Developments and Applications. " The term photonics covers both optics and optical engineering areas of growing sci­ entific and commercial importance throughout the world. It is estimated that photonic tech­ nology-related applications to increase exponentially over the next few years and will play a significant role in the global economy by reaching a quarter of a trillion of US dollars by the year 2000. The global interest and advancements of this technology are represented in this book, where leading scientists of twenty-two countries with advanced technology in photon­ ics present their latest results. The papers selected herein are ...

  10. All-optical signal processing at 10 GHz using a photonic crystal molecule

    Energy Technology Data Exchange (ETDEWEB)

    Combrié, Sylvain; Lehoucq, Gaëlle; Junay, Alexandra; De Rossi, Alfredo, E-mail: alfredo.derossi@thalesgroup.com [Thales Research and Technology, 1 Avenue A. Fresnel, 91767 Palaiseau (France); Malaguti, Stefania; Bellanca, Gaetano; Trillo, Stefano [Department of Engineering, Università di Ferrara, v. Saragat 1, 44122 Ferrara (Italy); Ménager, Loic [Thales Systèmes Aeroportés, 2 Av. Gay Lussac, 78851 Elancourt (France); Peter Reithmaier, Johann [Institute of Nanostructure Technologies and Analytics, CINSaT, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel (Germany)

    2013-11-04

    We report on 10 GHz operation of an all-optical gate based on an Indium Phosphide Photonic Crystal Molecule. Wavelength conversion and all-optical mixing of microwave signals are demonstrated using the 2 mW output of a mode locked diode laser. The spectral separation of the optical pump and signal is crucial in suppressing optical cross-talk.

  11. Chaos in coherent two-photon processes in a ring cavity

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S; Agarwal, G S

    1983-08-01

    The output of a ring cavity containing a resonant medium undergoing two photon transitions is shown to become chaotic, after following a series of bifurcations involving 2 to the nth cycles, as the strength of the driving field is increased. The chaotic regime is followed by a sequence of period doubling bifurcations in reverse order. 14 references.

  12. Measurement of exclusive $\\rho^{+}\\rho^{-}$ production in mid-virtuality two-photon interactions and study of the $\\gamma \\gamma^{*} \\to \\rho\\rho$ process at LEP

    CERN Document Server

    Achard, P.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M.G.; Anderhub, H.; Andreev, Valery P.; Anselmo, F.; Arefiev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S.V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillere, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B.L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J.J.; Blyth, S.C.; Bobbink, G.J.; Bohm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J.G.; Brochu, F.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y.H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G.M.; Chen, H.F.; Chen, H.S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; de Asmundis, R.; Deglon, P.; Debreczeni, J.; Degre, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M.T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F.J.; Extermann, P.; Falagan, M.A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J.H.; Filthaut, F.; Fisher, P.H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Iouri; Ganguli, S.N.; Garcia-Abia, Pablo; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z.F.; Grenier, Gerald Jean; Grimm, O.; Gruenewald, M.W.; Guida, M.; Gupta, V.K.; Gurtu, A.; Gutay, L.J.; Haas, D.; Hatzifotiadou, D.; Hebbeker, T.; Herve, Alain; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S.R.; Jin, B.N.; Jindal, P.; Jones, Lawrence W.; de Jong, P.; Josa-Mutuberria, I.; Kaur, M.; Kienzle-Focacci, M.N.; Kim, J.K.; Kirkby, Jasper; Kittel, W.; Klimentov, A.; Konig, A.C.; Kopal, M.; Koutsenko, V.; Kraber, M.; Kraemer, R.W.; Kruger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J.M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C.H.; Lin, W.T.; Linde, F.L.; Lista, L.; Liu, Z.A.; Lohmann, W.; Longo, E.; Lu, Y.S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W.G.; Malgeri, L.; Malinin, A.; Mana, C.; Mans, J.; Martin, J.P.; Marzano, F.; Mazumdar, K.; McNeil, R.R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W.J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G.B.; Muanza, G.S.; Muijs, A.J.M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Kluge, Hannelies; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, Thomas Cantzon; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroue, P.A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofiev, D.; Rahal-Callot, G.; Rahaman, Mohammad Azizur; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P.G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, Keith; Roe, B.P.; Romero, L.; Rosca, A.; Rosemann, C.; Rosenbleck, C.; Rosier-Lees, S.; Roth, Stefan; Rubio, J.A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schafer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D.J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D.P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L.Z.; Sushkov, S.; Suter, H.; Swain, J.D.; Szillasi, Z.; Tang, X.W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, Charles; Ting, Samuel C.C.; Ting, S.M.; Tonwar, S.C.; Toth, J.; Tully, C.; Tung, K.L.; Ulbricht, J.; Valente, E.; Van de Walle, R.T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobiev, I.; Vorobyov, A.A.; Wadhwa, M.; Wang, Q.; Wang, X.L.; Wang, Z.M.; Weber, M.; Wynhoff, S.; Xia, L.; Xu, Z.Z.; Yamamoto, J.; Yang, B.Z.; Yang, C.G.; Yang, H.J.; Yang, M.; Yeh, S.C.; Zalite, An.; Zalite, Yu.; Zhang, Z.P.; Zhao, J.; Zhu, G.Y.; Zhu, R.Y.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.; Zoller, M.

    2005-01-01

    Exclusive rho+rho- production in two-photon collisions between a quasi-real photon, gamma, and a mid-virtuality photon, gamma*, is studied with data collected at LEP at centre-of-mass energies root(s)=183-209GeV with a total integrated luminosity of 684.8pb^-1. The cross section of the gamma gamma* -> rho+ rho- process is determined as a function of the photon virtuality, Q^2, and the two-photon centre-of-mass energy, W_gg, in the kinematic region: 0.2GeV^2 rho rho process over the Q^2-region 0.2GeV^2 < Q^2 < 30 GeV^2.

  13. The Importance of Locally Embedded Personal Relationships for SME Internationalisation Processes – from Opportunity Recognition to Company Growth

    Directory of Open Access Journals (Sweden)

    Milena Ratajczak-Mrozek

    2014-01-01

    Full Text Available The purpose of the paper is to present the importance of locally embedded personal relationships and individuals’ networks for the rise of small and medium enterprises (SMEs’ opportunities in the internationalisation process (especially the market entry phase as well as their international operations and growth. Above all, the aim of the article is to answer the question what is influencing the actual impact of these resulting opportunities on internationalisation and growth. This paper adopts both a conceptual and empirical approach to the problem based upon a critical review of pertinent literature. Two case studies of companies from industries representing different levels of technological advancement, that is the furniture industry and IT industry, are presented. The theoretical and empirical analysis presented in the article points to the fact that relationships simultaneously facilitate opportunity recognition and themselves constitute such an opportunity. The analysis carried out as part of the case study proves that main factors determining the rise of the opportunity based on locally embedded personal relationships are trust and mutual understanding, in this way emphasising the importance of relational embeddedness. At the same time the realisation of these opportunities and therefore their impact on the internationalisation process and a company’s growth requires additional social factors (an entrepreneurial attitude as well as economic factors (such as quality and competitive prices.

  14. Photonic crystal fiber as lab-in-fiber optofluidic platform for sensing and process monitoring

    Science.gov (United States)

    Tian, Fei

    The ability to design and fabricate photonic crystal fiber (PCF) of vastly different microstructural and optical characteristics is arguably one of the most significant recent advances in the field of fiber optics. This dissertation aims to advance the PCF research frontier by exploring long-period fiber gratings (LPG) inscribed in PCF for sensing and process monitoring via combined numerical and experimental investigation. Specifically, a mode solver based on the Finite Element Method (FEM) has been employed to calculate the mode field distribution, the phase matching condition, and the dispersive characteristics associated with LPG-induced coupling of the fundamental core mode (LP01) to various cladding modes (LPmn, m=0,1; n=2,3, ...) in an endlessly single mode PCF. The numerical results have been used to guide the design and fabrication of LPG in PCF by CO2 laser inscription to maximize index sensitivity in gas or liquid medium. Cascaded PCF-LPG has been fabricated and shown to exhibit record sensitivity in excess of 1700 nm/RIU with high resolution for index measurements of gas phase. The inherent interference fringes in the transmission spectrum of cascaded PCF-LPG have been utilized to analyze mode coupling behaviour. In addition, we have developed and implemented a reflective mirror-aided method to allow symmetrical CO2 laser irradiation of PCF during LPG inscription. Both numerical analysis and experimental measurements have shown significantly improved mode coupling behaviour, mode field distribution, as well as reproducibility in LPG fabrication, critical for practical exploitation of the PCF-LPG platform. We have further exploited the high index sensitivity of PCF-LPG to monitor layer-by-layer (LbL) self-assembly of poly(vinyl pyrrolidone) (PVPON) and poly(methacrylic acid) (PMAA) polyelectrolyte layers as well as the pH responsiveness of the cross-linked PMAA hydrogel films. A shift of ˜1.625 nm in the resonance wavelength per polyelectrolyte layer

  15. Empirical Study on Sustainable Opportunities Recognition. A Polyvinyl Chloride (PVC Joinery Industry Analysis Using Augmented Sustainable Development Process Model

    Directory of Open Access Journals (Sweden)

    Eduard-Gabriel Ceptureanu

    2017-09-01

    Full Text Available This paper analyzes factors influencing recognition of sustainable opportunities by using an augmented sustainability process model. The conceptual model used two main factors, Knowledge and Motivation, and one moderating variable, Social embeddedness. We investigated entrepreneurs from PVC joinery industry and concluded that while market orientation and sustainable entrepreneurial orientation definitely and positively influence sustainable opportunity recognition, others variables like knowledge of the natural/communal environment, awareness of sustainable development or focus on success have less support. Among all variables analyzed, perception of the threat of the natural/communal environment and altruism toward others have the poorest impact on opportunity recognition. Finally, we concluded that social embeddedness has a moderating effect on sustainable opportunity recognition, even though the results were mixed.

  16. Photon-photon collisions

    International Nuclear Information System (INIS)

    Burke, D.L.

    1982-10-01

    Studies of photon-photon collisions are reviewed with particular emphasis on new results reported to this conference. These include results on light meson spectroscopy and deep inelastic e#betta# scattering. Considerable work has now been accumulated on resonance production by #betta##betta# collisions. Preliminary high statistics studies of the photon structure function F 2 /sup #betta#/(x,Q 2 ) are given and comments are made on the problems that remain to be solved

  17. Opportunity Design

    DEFF Research Database (Denmark)

    Løwe Nielsen, Suna; Lassen, Astrid Heidemann; Nielsen, Louise Møller

    2013-01-01

    design”. The framework explains how opportunities intentionally and pro-actively can be designed from methods and processes of moving-in and moving-out. An illustrative case of opportunity design within the area of sustainable energy and electric cars is presented to link the theoretical discussion...

  18. Photon-photon colliders

    International Nuclear Information System (INIS)

    Sessler, A.M.

    1995-04-01

    Since the seminal work by Ginsburg, et at., the subject of giving the Next Linear Collider photon-photon capability, as well as electron-positron capability, has drawn much attention. A 1990 article by V.I. Teinov describes the situation at that time. In March 1994, the first workshop on this subject was held. This report briefly reviews the physics that can be achieved through the photon-photon channel and then focuses on the means of achieving such a collider. Also reviewed is the spectrum of backscattered Compton photons -- the best way of obtaining photons. We emphasize the spectrum actually obtained in a collider with both polarized electrons and photons (peaked at high energy and very different from a Compton spectrum). Luminosity is estimated for the presently considered colliders, and interaction and conversion-point geometries are described. Also specified are laser requirements (such as wavelength, peak power, and average power) and the lasers that might be employed. These include conventional and free-electron lasers. Finally, we describe the R ampersand D necessary to make either of these approaches viable and explore the use of the SLC as a test bed for a photon-photon collider of very high energy

  19. Photonuclear processes in the treatment room and patient during radiation therapy with 50 MV photons

    Energy Technology Data Exchange (ETDEWEB)

    Gudowska, Irena [Karolinska Inst., Stockholm (Sweden). Dept. of Radiation Physics

    1997-10-01

    The objectives of this project were to determine the level of photoneutron radiation around the MM50 Racetrack Microtron at Karolinska Hospital, operating in different modes and to evaluate the photonuclear absorbed dose to the treated volume during therapy with a 50 MV photon beam. The photoneutron radiation has been studied both using a {sup 235}U fission chamber and by computer simulation. The estimated neutron equivalent dose due to accelerator produced neutrons delivered to the tissues inside and outside the treatment volume do not exceed the recommended values. However, there is a potential risk that the sensitive tissues (lens of the eye and gonads), outside the treatment volume, can receive a dose of about 300-500 mSv per photon treatment course of 60 Gy with a slight increase for secondary malignancies. 47 refs, 15 figs, 6 tabs.

  20. Effects of noninstantaneous nonlinear processes on photon-pair generation by spontaneous four-wave mixing

    DEFF Research Database (Denmark)

    Koefoed, Jacob Gade; Christensen, Jesper Bjerge; Rottwitt, Karsten

    2017-01-01

    We present a general model, based on a Hamiltonian approach, for the joint quantum state of photon pairs generated through pulsed spontaneous four-wave mixing, including nonlinear phase modulation and a finite material response time. For the case of a silica fiber, it is found that the pair......-production rate depends weakly on the waveguide temperature, due to higher-order Raman scattering events, and more strongly on pump-pair frequency detuning. From the analytical model, a numerical scheme is derived, based on the well-known split-step method. This scheme allows computation of joint states where......-dependent change in quantum-mechanical purity may be observed in silica. This shows that Raman scattering not only introduces noise, but can also drastically change the spectral correlations in photon pairs when pumped with short pulses....

  1. Photonuclear processes in the treatment room and patient during radiation therapy with 50 MV photons

    International Nuclear Information System (INIS)

    Gudowska, Irena

    1997-01-01

    The objectives of this project were to determine the level of photoneutron radiation around the MM50 Racetrack Microtron at Karolinska Hospital, operating in different modes and to evaluate the photonuclear absorbed dose to the treated volume during therapy with a 50 MV photon beam. The photoneutron radiation has been studied both using a 235 U fission chamber and by computer simulation. The estimated neutron equivalent dose due to accelerator produced neutrons delivered to the tissues inside and outside the treatment volume do not exceed the recommended values. However, there is a potential risk that the sensitive tissues (lens of the eye and gonads), outside the treatment volume, can receive a dose of about 300-500 mSv per photon treatment course of 60 Gy with a slight increase for secondary malignancies. 47 refs, 15 figs, 6 tabs

  2. Nonlinear optical and multiphoton processes for in situ manipulation and conversion of photons: applications to energy and healthcare (Conference Presentation)

    Science.gov (United States)

    Prasad, Paras N.

    2017-02-01

    Chiral control of nonlinear optical functions holds a great promise for a wide range of applications including optical signal processing, bio-sensing and chiral bio-imaging. In chiral polyfluorene thin films, we demonstrated extremely large chiral nonlinearity. The physics of manipulating excitation dynamics for photon transformation will be discussed, along with nanochemistry control of upconversion in hierarchically built organic chromophore coupled-core-multiple shell nanostructures which enable introduce new, organic-inorganic energy transfer routes for broadband light harvesting and increased upconversion efficiency via multistep cascaded energy transfer. We are pursuing the applications of photon conversion technology in IR harvesting for photovoltaics, high contrast bioimaging, photoacoustic imaging, photodynamic therapy, and optogenetics. An important application is in Brain research and Neurophotonics for functional mapping and modulation of brain activities. Another new direction pursued is magnetic field control of light in in a chiral polymer nanocomposite to achieve large magneto-optic coefficient which can enable sensing of extremely weak magnetic field due to brain waves. Finally, we will consider the thought provoking concept of utilizing photons to quantify, through magneto-optics, and augment - through nanoptogenetics, the cognitive states, thus paving the path way to a quantified human paradigm.

  3. Probing temporal aspects of high-order harmonic pulses via multi-colour, multi-photon ionization processes

    Energy Technology Data Exchange (ETDEWEB)

    Mauritsson, J [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001 (United States); Johnsson, P [Department of Physics, Lund Institute of Technology, PO Box 118, SE-22100 Lund (Sweden); Lopez-Martens, R [Department of Physics, Lund Institute of Technology, PO Box 118, SE-22100 Lund (Sweden); Varju, K [Department of Physics, Lund Institute of Technology, PO Box 118, SE-22100 Lund (Sweden); L' Huillier, A [Department of Physics, Lund Institute of Technology, PO Box 118, SE-22100 Lund (Sweden); Gaarde, M B [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001 (United States); Schafer, K J [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001 (United States)

    2005-07-14

    High-order harmonics generated through the interaction of atoms and strong laser fields are a versatile, laboratory-scale source of extreme ultraviolet (XUV) radiation on a femtosecond or even attosecond time-scale. In order to be a useful experimental tool, however, this radiation has to be well characterized, both temporally and spectrally. In this paper we discuss how multi-photon, multi-colour ionization processes can be used to completely characterize either individual harmonics or attosecond pulse trains. In particular, we discuss the influence of the intensity and duration of the probe laser, and how these parameters effect the accuracy of the XUV characterization.

  4. Probing temporal aspects of high-order harmonic pulses via multi-colour, multi-photon ionization processes

    International Nuclear Information System (INIS)

    Mauritsson, J; Johnsson, P; Lopez-Martens, R; Varju, K; L'Huillier, A; Gaarde, M B; Schafer, K J

    2005-01-01

    High-order harmonics generated through the interaction of atoms and strong laser fields are a versatile, laboratory-scale source of extreme ultraviolet (XUV) radiation on a femtosecond or even attosecond time-scale. In order to be a useful experimental tool, however, this radiation has to be well characterized, both temporally and spectrally. In this paper we discuss how multi-photon, multi-colour ionization processes can be used to completely characterize either individual harmonics or attosecond pulse trains. In particular, we discuss the influence of the intensity and duration of the probe laser, and how these parameters effect the accuracy of the XUV characterization

  5. Mode-selective mapping and control of vectorial nonlinear-optical processes in multimode photonic-crystal fibers.

    Science.gov (United States)

    Hu, Ming-Lie; Wang, Ching-Yue; Song, You-Jian; Li, Yan-Feng; Chai, Lu; Serebryannikov, Evgenii; Zheltikov, Aleksei

    2006-02-06

    We demonstrate an experimental technique that allows a mapping of vectorial nonlinear-optical processes in multimode photonic-crystal fibers (PCFs). Spatial and polarization modes of PCFs are selectively excited in this technique by varying the tilt angle of the input beam and rotating the polarization of the input field. Intensity spectra of the PCF output plotted as a function of the input field power and polarization then yield mode-resolved maps of nonlinear-optical interactions in multimode PCFs, facilitating the analysis and control of nonlinear-optical transformations of ultrashort laser pulses in such fibers.

  6. Processing method of images obtained during the TESIS/CORONAS-PHOTON experiment

    Science.gov (United States)

    Kuzin, S. V.; Shestov, S. V.; Bogachev, S. A.; Pertsov, A. A.; Ulyanov, A. S.; Reva, A. A.

    2011-04-01

    In January 2009, the CORONAS-PHOTON spacecraft was successfully launched. It includes a set of telescopes and spectroheliometers—TESIS—designed to image the solar corona in soft X-ray and EUV spectral ranges. Due to features of the reading system, to obtain physical information from these images, it is necessary to preprocess them, i.e., to remove the background, correct the white field, level, and clean. The paper discusses the algorithms and software developed and used for the preprocessing of images.

  7. Poisson pre-processing of nonstationary photonic signals: Signals with equality between mean and variance

    Czech Academy of Sciences Publication Activity Database

    Poplová, Michaela; Sovka, P.; Cifra, Michal

    2017-01-01

    Roč. 12, č. 12 (2017), č. článku e0188622. E-ISSN 1932-6203 R&D Projects: GA ČR(CZ) GA13-29294S Grant - others:AV ČR(CZ) SAV-15-22 Program:Bilaterální spolupráce Institutional support: RVO:67985882 Keywords : Poisson distribution * Photons * Neutrophils Subject RIV: JB - Sensors, Measurment, Regulation OBOR OECD: Electrical and electronic engineering Impact factor: 2.806, year: 2016

  8. All-optical signal processing using InP photonic-crystal nanocavity switches

    DEFF Research Database (Denmark)

    Yu, Yi; Vukovic, Dragana; Heuck, Mikkel

    2014-01-01

    In this paper, we present recent progress in experimental characterization of InP photonic-crystal nanocavity switches. Pump-probe measurements on an InP PhC H0 cavity show large-contrast ultrafast switching at low pulse energy. At large pulse energies, a large resonance shift passing across...... for the joint effects of fast carrier diffusion, slow surface and bulk recombination. Utilizin g the simple InP PhC nanocavity structure, we successfully dem onstrate 10-Gb/s RZ- OOK all-optical modulation with low energy consumption....

  9. Two-photon physics

    International Nuclear Information System (INIS)

    Bardeen, W.A.

    1981-10-01

    A new experimental frontier has recently been opened to the study of two photon processes. The first results of many aspects of these reactions are being presented at this conference. In contrast, the theoretical development of research ito two photon processes has a much longer history. This talk reviews the many different theoretical ideas which provide a detailed framework for our understanding of two photon processes

  10. Causation and Effectuation Processes: Opportunity Discovery and Exploitation Logics of Habitual Entrepreneurs

    DEFF Research Database (Denmark)

    Müller, Sabine

    2010-01-01

    This study investigates how habitual entrepreneurs (i.e. serial and portfolio entrepreneurs) discover and exploit opportunities, deal with risk and uncertainty, predict or control the future, and plan their businesses based on a causation and effectuation perspective. This study thereby uncovered...... the causation and effectuation logics applied by habitual entrepreneurs with regard to four dimensions of the venture creation: View of the future (VF), Opportunity Discovery (OD), Opportunity Exploitation (OE), and Dealing with Risk (DR). Six habitual entrepreneurs, who had to meet three strictly defined...... criteria, where sampled and case studies performed. The findings clearly indicate that habitual entrepreneurs mainly apply an effectual logic with regards to the four dimensions examined. Some of the more inexperienced habitual entrepreneurs tend to apply both logics, but almost exclusively become...

  11. Photon-Photon Collisions -- Past and Future

    International Nuclear Information System (INIS)

    Brodsky, Stanley J.

    2005-01-01

    I give a brief review of the history of photon-photon physics and a survey of its potential at future electron-positron colliders. Exclusive hadron production processes in photon-photon and electron-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes. There are also important high energy γγ and eγ tests of quantum chromodynamics, including the production of jets in photon-photon collisions, deeply virtual Compton scattering on a photon target, and leading-twist single-spin asymmetries for a photon polarized normal to a production plane. Since photons couple directly to all fundamental fields carrying the electromagnetic current including leptons, quarks, W's and supersymmetric particles, high energy γγ collisions will provide a comprehensive laboratory for Higgs production and exploring virtually every aspect of the Standard Model and its extensions. High energy back-scattered laser beams will thus greatly extend the range of physics of the International Linear Collider

  12. Photonic Crystals Towards Nanoscale Photonic Devices

    CERN Document Server

    Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexei; Pagnoux, Dominique

    2008-01-01

    Just like the periodical crystalline potential in solid state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as cages for storing, filtering or guiding light at the wavelength scale paves the way to the realization of optical and optoelectronic devices with ultimate properties and dimensions. This will contribute towards meeting the demands for greater miniaturization imposed by the processing of an ever increasing number of data. Photonic Crystals will provide students and researchers from different fields with the theoretical background required for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, ranging from optics to microwaves, where photonic crystals have found application. As such, it aims at building bridges between...

  13. Photonic Crystals Towards Nanoscale Photonic Devices

    CERN Document Server

    Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexis

    2005-01-01

    Just like the periodical crystalline potential in solid-state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as a cage for storing, filtering or guiding light at the wavelength scale thus paves the way to the realisation of optical and optoelectronic devices with ultimate properties and dimensions. This should contribute toward meeting the demands for a greater miniaturisation that the processing of an ever increasing number of data requires. Photonic Crystals intends at providing students and researchers from different fields with the theoretical background needed for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, from optics to microwaves, where photonic crystals have found applications. As such, it aims at building brid...

  14. The risks of inclusion: shifts in governance processes and upgrading opportunities for cocoa farmers in Ghana

    NARCIS (Netherlands)

    Laven, A.C.

    2010-01-01

    This PhD study provides a detailed description and analysis of upgrading opportunities for small-scale cocoa farmers in Ghana. It shows how and why producers do, or do not, benefit from being inserted in a global value chain that is increasingly driven by multinational cocoa processors and chocolate

  15. Recent measurements of two photon muon pair process from Mark J at √s up to 46.78 GeV

    International Nuclear Information System (INIS)

    Zhang, C.C.

    1985-07-01

    The recent results from Mark J on two photon muon pair production with √s from 14 to 46.78 GeV are presented, and compared with the complete α 4 QED calculation in a large range of √s and four momentum transfer, including untagged, single and double tagged events. The forward-backward charge asymmetry of muons produced in the two photon process is also compared to the QED prediction. (orig.)

  16. UV photon and low-energy (5--150 eV) electron-stimulated processes at environmental interfaces

    International Nuclear Information System (INIS)

    Orlando, T.M.

    1997-01-01

    Irradiation of surfaces and interfaces with low-energy (5--150 eV) electrons and ultraviolet photons occurs during the storage of ''mixed'' (chemical/radioactive) waste forms and during processing steps which involve the use of low temperature plasmas. It is well known that electron- and photon-stimulated desorption (ESD and PSD) from wide band-gap materials and interfaces can be initiated by Auger decay of deep valence and shallow core holes. This process consists of hole production, Auger decay, reversal of the Madelung potential, and ion expulsion due to the Coulomb repulsion. ESD and PSD of neutrals also occurs and involves production of electron-hole pairs and excitons. Generally, neutral yields dominate ESD and PSD cross sections, which typically vary between ∼10 -16 and 10 -22 cm 2 . The authors present results on the ESD and PSD of environmentally relevant substrates such as ZrO 2 (100), soda-glass, and NaNO 3 . The major cation thresholds and yields indicate that ESD and PSD from these complex materials involves Auger stimulated events. In particular, desorption thresholds correlate with ionization of the O(2s), Zr(4p), Si(2p) and Na(2s) levels. The near band-gap threshold energy (∼5--7 eV) for the desorption of neutrals (i.e., atomic oxygen, NO, etc) demonstrate the overall importance of self-trapped and localized excitons in both ESD and PSD of typical ceramics and oxides

  17. Microfluidics and thin-film processes: a recipe for organic integrated photonics based on 3D microresonators

    Science.gov (United States)

    Huby, N.; Pluchon, D.; Belloul, M.; Moreac, A.; Coulon, N.; Gaviot, E.; Panizza, P.; B"che, B.

    2010-02-01

    We report on the design and realization of photonic integrated devices based on 3D organic microresonators. This has been achieved by combining microfluidics techniques and thin-film processes. The microfluidic device and the control of the flow rates of the continuous and dispersed phases allow the fabrication of organic microresonators with diameter ranging from 30 to 200 μm. The resonance of the sphere in air has been first investigated by using the Raman spectroscopy set-up demonstrating the appropriate photonic properties. Then the microresonators have been integrated on an organic chip made of the photosensitive resin SU-8 and positioned at the extremity of a taper and alongside a rib waveguide. The realization of these structures by thin-film processes needs one step UV-lithography leading to 6μm width and 30μm height. Both devices have proved the efficient evanescent coupling leading to the excitation of the whispering gallery modes confined at the surface of the organic 3D microresonators. Finally, a band-stop filter has been used to detect the resonance spectra of the resonators once integrated.

  18. Multi-photon absorption limits to heralded single photon sources

    Science.gov (United States)

    Husko, Chad A.; Clark, Alex S.; Collins, Matthew J.; De Rossi, Alfredo; Combrié, Sylvain; Lehoucq, Gaëlle; Rey, Isabella H.; Krauss, Thomas F.; Xiong, Chunle; Eggleton, Benjamin J.

    2013-01-01

    Single photons are of paramount importance to future quantum technologies, including quantum communication and computation. Nonlinear photonic devices using parametric processes offer a straightforward route to generating photons, however additional nonlinear processes may come into play and interfere with these sources. Here we analyse spontaneous four-wave mixing (SFWM) sources in the presence of multi-photon processes. We conduct experiments in silicon and gallium indium phosphide photonic crystal waveguides which display inherently different nonlinear absorption processes, namely two-photon (TPA) and three-photon absorption (ThPA), respectively. We develop a novel model capturing these diverse effects which is in excellent quantitative agreement with measurements of brightness, coincidence-to-accidental ratio (CAR) and second-order correlation function g(2)(0), showing that TPA imposes an intrinsic limit on heralded single photon sources. We build on these observations to devise a new metric, the quantum utility (QMU), enabling further optimisation of single photon sources. PMID:24186400

  19. Probing the structure of the virtual photon in the deep inelastic Compton process at the DESY HERA collider

    International Nuclear Information System (INIS)

    Krawczyk, M.; Zembrzuski, A.

    1998-01-01

    The sensitivity of deep inelastic Compton (DIC) scattering at DESY HERA to the structure of the virtual photon is discussed. It is demonstrated that the gluonic content of the virtual photon can be pinned down by measuring the photons with p T ∼5 GeV in the proton direction. copyright 1997 The American Physical Society

  20. [Study on spectral gain characterization of FWM processes with multi-frequency pumps in photonic crystal fiber].

    Science.gov (United States)

    Hui, Zhan-Qiang

    2011-10-01

    Spectral gain induced by four-wave-mixing with multi-frequency pump was investigated by exploiting the data signal and continue lights co-propagation in dispersion flattened high nonlinear photonic crystal fiber (PCF). The effects of wavelength drift of pump lights, polarization state of orthogonal or parallel of pump lights, polarization mismatch of signal light versus orthogonal pump lights, total power of signal and probe light on the spectrum gain were analyzed. The results show that good FWM gain effects with multi-frequency pump can be obtained in 36.4 nm wavelength range when power ratio of pump to probe light is appropriate and with identical polarization. Furthermore, the gain of FWM with multi-frequency pump is very sensitive to polarization fluctuation and the different idle waves obtain different gain with the variation in signal polarization state. Moreover, the impact of pump numbers was investigated. The obtained results would be helpful for further research on ultrahigh-speed all optical signal processing devices exploiting the FWM with multi-frequency pump in PCF for future photonics network.

  1. Photon-photon collisions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1985-01-01

    The study of photon-photon collisions has progressed enormously, stimulated by new data and new calculational tools for QCD. In the future we can expect precise determinations of ..cap alpha../sub s/ and ..lambda../sup ms/ from the ..gamma..*..gamma.. ..-->.. ..pi../sup 0/ form factor and the photon structure function, as well as detailed checks of QCD, determination of the shape of the hadron distribution amplitudes from ..gamma gamma.. ..-->.. H anti H, reconstruction of sigma/sub ..gamma gamma../ from exclusive channels at low W/sub ..gamma gamma../, definitive studies of high p/sub T/ hadron and jet production, and studies of threshold production of charmed systems. Photon-photon collisions, along with radiative decays of the psi and UPSILON, are ideal for the study of multiquark and gluonic resonances. We have emphasized the potential for resonance formation near threshold in virtually every hadronic exclusive channel, including heavy quark states c anti c c anti c, c anti c u anti u, etc. At higher energies SLC, LEP, ...) parity-violating electroweak effects and Higgs production due to equivalent Z/sup 0/ and W/sup + -/ beams from e ..-->.. eZ/sup 0/ and e ..-->.. nu W will become important. 44 references.

  2. Photon-photon collisions

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1985-01-01

    The study of photon-photon collisions has progressed enormously, stimulated by new data and new calculational tools for QCD. In the future we can expect precise determinations of α/sub s/ and Λ/sup ms/ from the γ*γ → π 0 form factor and the photon structure function, as well as detailed checks of QCD, determination of the shape of the hadron distribution amplitudes from γγ → H anti H, reconstruction of sigma/sub γγ/ from exclusive channels at low W/sub γγ/, definitive studies of high p/sub T/ hadron and jet production, and studies of threshold production of charmed systems. Photon-photon collisions, along with radiative decays of the psi and UPSILON, are ideal for the study of multiquark and gluonic resonances. We have emphasized the potential for resonance formation near threshold in virtually every hadronic exclusive channel, including heavy quark states c anti c c anti c, c anti c u anti u, etc. At higher energies SLC, LEP, ...) parity-violating electroweak effects and Higgs production due to equivalent Z 0 and W +- beams from e → eZ 0 and e → nu W will become important. 44 references

  3. Packaged semiconductor laser optical phase locked loop for photonic generation, processing and transmission of microwave signals

    DEFF Research Database (Denmark)

    Langley, L.N.; Elkin, M.D.; Edege, C.

    1999-01-01

    In this paper, we present the first fully packaged semiconductor laser optical phase-locked loop (OPLL) microwave photonic transmitter. The transmitter is based on semiconductor lasers that are directly phase locked without the use of any other phase noise-reduction mechanisms. In this transmitter......, the lasers have a free-running summed linewidth of 6 MHz and the OPLL has a feedback bandwidth of 70 MHz, A state-of-the-art performance is obtained, with a total phase-error variance of 0.05 rad(2) (1-GHz bandwidth) and a carrier phase-error variance of 7x10(-4) rad(2) in a 15-MHz bandwidth. Carriers...... are generated in the range of 7-14 GHz. The OPLL transmitter has been fully packaged for practical use in field trials. This is the first time this type of transmitter has been fabricated in a packaged state which is a significant advance on the route to practical application....

  4. Studies into tau reconstruction, missing transverse energy and photon induced processes with the ATLAS detector at the LHC

    International Nuclear Information System (INIS)

    Prabhu, Robindra P.

    2011-09-01

    The ATLAS experiment is currently recording data from proton-proton collisions delivered by CERN's Large Hadron Collider. As more data is amassed, studies of both Standard Model processes and searches for new physics beyond will intensify. This dissertation presents a three-part study providing new methods to help facilitate these efforts. The first part presents a novel τ-reconstruction algorithm for ATLAS inspired by the ideas of particle flow calorimetry. The algorithm is distinguished from traditional τ-reconstruction approaches in ATLAS, insofar that it seeks to recognize decay topologies consistent with a (hadronically) decaying τ-lepton using resolved energy flow objects in the calorimeters. This procedure allows for an early classification of τ-candidates according to their decay mode and the use of decay mode specific discrimination against fakes. A detailed discussion of the algorithm is provided along with early performance results derived from simulated data. The second part presents a Monte Carlo simulation tool which by way of a pseudorapidity-dependent parametrization of the jet energy resolution, provides a probabilistic estimate for the magnitude of instrumental contributions to missing transverse energy arising from jet fluctuations. The principles of the method are outlined and it is shown how the method can be used to populate tails of simulated missing transverse energy distributions suffering from low statistics. The third part explores the prospect of detecting photon-induced leptonic final states in early data. Such processes are distinguished from the more copious hadronic interactions at the LHC by cleaner final states void of hadronic debris, however the soft character of the final state leptons poses challenges to both trigger and offline selections. New trigger items enabling the online selection of such final states are presented, along with a study into the feasibility of detecting the two-photon exchange process pp(γγ →

  5. Studies into tau reconstruction, missing transverse energy and photon induced processes with the ATLAS detector at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Prabhu, Robindra P.

    2011-09-15

    The ATLAS experiment is currently recording data from proton-proton collisions delivered by CERN's Large Hadron Collider. As more data is amassed, studies of both Standard Model processes and searches for new physics beyond will intensify. This dissertation presents a three-part study providing new methods to help facilitate these efforts. The first part presents a novel {tau}-reconstruction algorithm for ATLAS inspired by the ideas of particle flow calorimetry. The algorithm is distinguished from traditional {tau}-reconstruction approaches in ATLAS, insofar that it seeks to recognize decay topologies consistent with a (hadronically) decaying {tau}-lepton using resolved energy flow objects in the calorimeters. This procedure allows for an early classification of {tau}-candidates according to their decay mode and the use of decay mode specific discrimination against fakes. A detailed discussion of the algorithm is provided along with early performance results derived from simulated data. The second part presents a Monte Carlo simulation tool which by way of a pseudorapidity-dependent parametrization of the jet energy resolution, provides a probabilistic estimate for the magnitude of instrumental contributions to missing transverse energy arising from jet fluctuations. The principles of the method are outlined and it is shown how the method can be used to populate tails of simulated missing transverse energy distributions suffering from low statistics. The third part explores the prospect of detecting photon-induced leptonic final states in early data. Such processes are distinguished from the more copious hadronic interactions at the LHC by cleaner final states void of hadronic debris, however the soft character of the final state leptons poses challenges to both trigger and offline selections. New trigger items enabling the online selection of such final states are presented, along with a study into the feasibility of detecting the two-photon exchange process

  6. Quantum photonic networks in diamond

    KAUST Repository

    Lončar, Marko; Faraon, Andrei

    2013-01-01

    Advances in nanotechnology have enabled the opportunity to fabricate nanoscale optical devices and chip-scale systems in diamond that can generate, manipulate, and store optical signals at the single-photon level. In particular, nanophotonics has

  7. Multi-format all-optical processing based on a large-scale, hybridly integrated photonic circuit.

    Science.gov (United States)

    Bougioukos, M; Kouloumentas, Ch; Spyropoulou, M; Giannoulis, G; Kalavrouziotis, D; Maziotis, A; Bakopoulos, P; Harmon, R; Rogers, D; Harrison, J; Poustie, A; Maxwell, G; Avramopoulos, H

    2011-06-06

    We investigate through numerical studies and experiments the performance of a large scale, silica-on-silicon photonic integrated circuit for multi-format regeneration and wavelength-conversion. The circuit encompasses a monolithically integrated array of four SOAs inside two parallel Mach-Zehnder structures, four delay interferometers and a large number of silica waveguides and couplers. Exploiting phase-incoherent techniques, the circuit is capable of processing OOK signals at variable bit rates, DPSK signals at 22 or 44 Gb/s and DQPSK signals at 44 Gbaud. Simulation studies reveal the wavelength-conversion potential of the circuit with enhanced regenerative capabilities for OOK and DPSK modulation formats and acceptable quality degradation for DQPSK format. Regeneration of 22 Gb/s OOK signals with amplified spontaneous emission (ASE) noise and DPSK data signals degraded with amplitude, phase and ASE noise is experimentally validated demonstrating a power penalty improvement up to 1.5 dB.

  8. CMOS-compatible photonic devices for single-photon generation

    Directory of Open Access Journals (Sweden)

    Xiong Chunle

    2016-09-01

    Full Text Available Sources of single photons are one of the key building blocks for quantum photonic technologies such as quantum secure communication and powerful quantum computing. To bring the proof-of-principle demonstration of these technologies from the laboratory to the real world, complementary metal–oxide–semiconductor (CMOS-compatible photonic chips are highly desirable for photon generation, manipulation, processing and even detection because of their compactness, scalability, robustness, and the potential for integration with electronics. In this paper, we review the development of photonic devices made from materials (e.g., silicon and processes that are compatible with CMOS fabrication facilities for the generation of single photons.

  9. Photon-Photon Luminosities in Relativistic Heavy Ion Collisions at LHC Energies

    OpenAIRE

    Hencken, Kai; Trautmann, Dirk; Baur, Gerhard

    1994-01-01

    Effective photon-photon luminosities are calculated for various realistic hadron collider scenarios. The main characteristics of photon-photon processes at relativistic heavy-ion colliders are established and compared to the corresponding photon-photon luminosities at electron-positron and future Photon Linear Colliders (PLC). Higher order corrections as well as inelastic processes are discussed. It is concluded that feasible high luminosity Ca-Ca collisions at the Large Hadron Collider (LHC)...

  10. Photonics in South Africa

    CSIR Research Space (South Africa)

    Bollig, C

    2007-12-01

    Full Text Available : photonics, ultrafast and ultra- intense laser science (Heinrich Schwoerer, University of Stellenbosch); quantum information processing and communication (Francesco Petruccione, University of KwaZulu-Natal); medicinal chemistry and nanotechnology... of experience in diamond research, where scientists are now turning their attention to diamond for photonic devices. �ere is an active community in South Africa studying the potential of diamond as a single-photon source for applications in quantum...

  11. Integrated Microwave Photonics

    OpenAIRE

    Marpaung, David; Roeloffzen, Chris; Heideman, René; Leinse, Arne; Sales Maicas, Salvador; Capmany Francoy, José

    2013-01-01

    Microwave photonics (MWP) is an emerging field in which radio frequency (RF) signals are generated, distributed, processed and analyzed using the strength of photonic techniques. It is a technology that enables various functionalities which are not feasible to achieve only in the microwave domain. A particular aspect that recently gains significant interests is the use of photonic integrated circuit (PIC) technology in the MWP field for enhanced functionalities and robustness as well as the r...

  12. Silicon Photonics for Signal Processing of Tbit/s Serial Data Signals

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Ji, Hua; Galili, Michael

    2012-01-01

    In this paper, we describe our recent work on signal processing of terabit per second optical serial data signals using pure silicon waveguides. We employ nonlinear optical signal processing in nanoengineered silicon waveguides to perform demultiplexing and optical waveform sampling of 1.28-Tbit/...

  13. Opportunity Design

    DEFF Research Database (Denmark)

    Nielsen, Louise Møller; Lassen, Astrid Heidemann; Tollestrup, Christian

    2012-01-01

    Creating and growing new businesses is basically about turning an entrepreneurial opportunity into future business. In literature the emergence of opportunities is often described as opportunity recognition or opportunity discovery, which points to the understanding that opportunities are out the...

  14. Novel ultra-wideband photonic signal generation and transmission featuring digital signal processing bit error rate measurements

    DEFF Research Database (Denmark)

    Gibbon, Timothy Braidwood; Yu, Xianbin; Tafur Monroy, Idelfonso

    2009-01-01

    We propose the novel generation of photonic ultra-wideband signals using an uncooled DFB laser. For the first time we experimentally demonstrate bit-for-bit DSP BER measurements for transmission of a 781.25 Mbit/s photonic UWB signal.......We propose the novel generation of photonic ultra-wideband signals using an uncooled DFB laser. For the first time we experimentally demonstrate bit-for-bit DSP BER measurements for transmission of a 781.25 Mbit/s photonic UWB signal....

  15. Waste heat and water recovery opportunities in California tomato paste processing

    International Nuclear Information System (INIS)

    Amón, Ricardo; Maulhardt, Mike; Wong, Tony; Kazama, Don; Simmons, Christopher W.

    2015-01-01

    Water and energy efficiency are important for the vitality of the food processing industry as demand for these limited resources continues to increase. Tomato processing, which is dominated by paste production, is a major industry in California – where the majority of tomatoes are processed in the United States. Paste processing generates large amounts of condensate as moisture is removed from the fruit. Recovery of the waste heat in this condensate and reuse of the water may provide avenues to decrease net energy and water use at processing facilities. However, new processing methods are needed to create demand for the condensate waste heat. In this study, the potential to recover condensate waste heat and apply it to the tomato enzyme thermal inactivation processing step (the hot break) is assessed as a novel application. A modeling framework is established to predict heat transfer to tomatoes during the hot break. Heat recovery and reuse of the condensate water are related to energy and monetary savings gained through decreased use of steam, groundwater pumping, cooling towers, and wastewater processing. This analysis is informed by water and energy usage data from relevant unit operations at a commercial paste production facility. The case study indicates potential facility seasonal energy and monetary savings of 7.3 GWh and $166,000, respectively, with most savings gained through reduced natural gas use. The sensitivity of heat recovery to various process variables associated with heat exchanger design and processing conditions is presented to identify factors that affect waste heat recovery. - Highlights: • The potential to recovery waste heat in tomato paste processing is examined. • Heat transfer from evaporator condensate to tomatoes in the hot break is modeled. • Processing facility data is used in model to predict heat recovery energy savings. • The primary benefit of heat recovery is reduced use of natural gas in boilers. • Reusing

  16. CONFERENCE: Photon-photon collisions

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Despite being difficult to observe, photon-photon collisions have opened up a range of physics difficult, or even impossible, to access by other methods. The progress which has been made in this field was evident at the fifth international workshop on photon-photon collisions, held in Aachen from 13-16 April and attended by some 120 physicists

  17. Experimental photonic generation of chirped pulses using nonlinear dispersion-based incoherent processing.

    Science.gov (United States)

    Rius, Manuel; Bolea, Mario; Mora, José; Ortega, Beatriz; Capmany, José

    2015-05-18

    We experimentally demonstrate, for the first time, a chirped microwave pulses generator based on the processing of an incoherent optical signal by means of a nonlinear dispersive element. Different capabilities have been demonstrated such as the control of the time-bandwidth product and the frequency tuning increasing the flexibility of the generated waveform compared to coherent techniques. Moreover, the use of differential detection improves considerably the limitation over the signal-to-noise ratio related to incoherent processing.

  18. A new window of opportunity to reject process-based biotechnology regulation.

    Science.gov (United States)

    Marchant, Gary E; Stevens, Yvonne A

    2015-01-01

    The question of whether biotechnology regulation should be based on the process or the product has long been debated, with different jurisdictions adopting different approaches. The European Union has adopted a process-based approach, Canada has adopted a product-based approach, and the United States has implemented a hybrid system. With the recent proliferation of new methods of genetic modification, such as gene editing, process-based regulatory systems, which are premised on a binary system of transgenic and conventional approaches, will become increasingly obsolete and unsustainable. To avoid unreasonable, unfair and arbitrary results, nations that have adopted process-based approaches will need to migrate to a product-based approach that considers the novelty and risks of the individual trait, rather than the process by which that trait was produced. This commentary suggests some approaches for the design of such a product-based approach.

  19. Photonic Integrated Circuits

    Science.gov (United States)

    Krainak, Michael; Merritt, Scott

    2016-01-01

    Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.

  20. Global change and modern coral reefs: New opportunities to understand shallow-water carbonate depositional processes

    Science.gov (United States)

    Hallock, Pamela

    2005-04-01

    Human activities are impacting coral reefs physically, biologically, and chemically. Nutrification, sedimentation, chemical pollution, and overfishing are significant local threats that are occurring worldwide. Ozone depletion and global warming are triggering mass coral-bleaching events; corals under temperature stress lose the ability to synthesize protective sunscreens and become more sensitive to sunlight. Photo-oxidative stress also reduces fitness, rendering reef-building organisms more susceptible to emerging diseases. Increasing concentration of atmospheric CO 2 has already reduced CaCO 3 saturation in surface waters by more than 10%. Doubling of atmospheric CO 2 concentration over pre-industrial concentration in the 21st century may reduce carbonate production in tropical shallow marine environments by as much as 80%. As shallow-water reefs decline worldwide, opportunities abound for researchers to expand understanding of carbonate depositional systems. Coordinated studies of carbonate geochemistry with photozoan physiology and calcification, particularly in cool subtropical-transition zones between photozoan-reef and heterotrophic carbonate-ramp communities, will contribute to understanding of carbonate sedimentation under environmental change, both in the future and in the geologic record. Cyanobacteria are becoming increasingly prominent on declining reefs, as these microbes can tolerate strong solar radiation, higher temperatures, and abundant nutrients. The responses of reef-dwelling cyanobacteria to environmental parameters associated with global change are prime topics for further research, with both ecological and geological implications.

  1. Photonics4All - Conduct photonics for investment in France and Slovakia

    OpenAIRE

    Gerente, Fiona; Chorvat, Dusan

    2017-01-01

    This project deliverable describes the organisation of different Photonics for Investment Events. “Photonics for investments” focuses on the support and investment in innovative ideas and photonics applications. The objective of this project task is to provide the opportunity for Photonics SMEs to present their products or services during pitch presentations to new customers and investors. The Photonics for Investment events have three main objectives. The first objective is to connect en...

  2. Single-photon sources

    International Nuclear Information System (INIS)

    Lounis, Brahim; Orrit, Michel

    2005-01-01

    The concept of the photon, central to Einstein's explanation of the photoelectric effect, is exactly 100 years old. Yet, while photons have been detected individually for more than 50 years, devices producing individual photons on demand have only appeared in the last few years. New concepts for single-photon sources, or 'photon guns', have originated from recent progress in the optical detection, characterization and manipulation of single quantum objects. Single emitters usually deliver photons one at a time. This so-called antibunching of emitted photons can arise from various mechanisms, but ensures that the probability of obtaining two or more photons at the same time remains negligible. We briefly recall basic concepts in quantum optics and discuss potential applications of single-photon states to optical processing of quantum information: cryptography, computing and communication. A photon gun's properties are significantly improved by coupling it to a resonant cavity mode, either in the Purcell or strong-coupling regimes. We briefly recall early production of single photons with atomic beams, and the operation principles of macroscopic parametric sources, which are used in an overwhelming majority of quantum-optical experiments. We then review the photophysical and spectroscopic properties and compare the advantages and weaknesses of various single nanometre-scale objects used as single-photon sources: atoms or ions in the gas phase and, in condensed matter, organic molecules, defect centres, semiconductor nanocrystals and heterostructures. As new generations of sources are developed, coupling to cavities and nano-fabrication techniques lead to improved characteristics, delivery rates and spectral ranges. Judging from the brisk pace of recent progress, we expect single photons to soon proceed from demonstrations to applications and to bring with them the first practical uses of quantum information

  3. Thinking Afresh About Processing: An Exploration of New Market Opportunities for Apple Products

    OpenAIRE

    Rowles, Kristin; Henehan, Brian M.; White, Gerald B.

    2001-01-01

    This report compiles the results of several studies focused on the markets for processed apple products. These studies were conducted as part of a multidisciplinary project examining the processing apple industry in the Northeastern United States. The purpose of the studies was to explore the potential for new products and new marketing strategies that might bring innovation to the apple industry. In the global and highly competitive markets in which apple products fight for shelf space and c...

  4. Nonlinear Dynamics of Photonics for Optical Signal Processing - Optical Frequency Conversion and Optical DSB-to-SSB Conversion

    Science.gov (United States)

    2015-09-17

    photonic system. ML: master laser; SL: slave laser; L; lens; PBS: polarizing beam splitter ; M: mirror; HW: half-wave plate; FR: Faraday rotator; V...microwave generation and stabilization, and photonic microwave amplification. 15. SUBJECT TERMS Non -linear Dynamics, Add-drop

  5. Integrated microwave photonics

    NARCIS (Netherlands)

    Marpaung, D.A.I.; Roeloffzen, C.G.H.; Heideman, Rene; Leinse, Arne; Sales, S.; Capmany, J.

    2013-01-01

    Microwave photonics (MWP) is an emerging field in which radio frequency (RF) signals are generated, distributed, processed and analyzed using the strength of photonic techniques. It is a technology that enables various functionalities which are not feasible to achieve only in the microwave domain. A

  6. Two Photon Distribution Amplitudes

    International Nuclear Information System (INIS)

    El Beiyad, M.; Pire, B.; Szymanowski, L.; Wallon, S.

    2008-01-01

    The factorization of the amplitude of the process γ*γ→γγ in the low energy and high photon virtuality region is demonstrated at the Born order and in the leading logarithmic approximation. The leading order two photon (generalized) distribution amplitudes exhibit a characteristic ln Q 2 behaviour and obey new inhomogeneous evolution equations

  7. Challenges and Opportunities in Reactive Processing and Applications of Advanced Ceramic Materials

    Science.gov (United States)

    Singh, Mrityunjay

    2003-01-01

    Recently, there has been a great deal of interest in the research, development, and commercialization of innovative synthesis and processing technologies for advanced ceramics and composite materials. Reactive processing approaches have been actively considered due to their robustness, flexibility, and affordability. A wide variety of silicon carbide-based advanced ceramics and composites are currently being fabricated using the processing approaches involving reactive infiltration of liquid and gaseous species into engineered fibrous or microporous carbon performs. The microporous carbon performs have been fabricated using the temperature induced phase separation and pyrolysis of two phase organic (resin-pore former) mixtures and fiber reinforcement of carbon and ceramic particulate bodies. In addition, pyrolyzed native plant cellulose tissues also provide unique carbon templates for manufacturing of non-oxide and oxide ceramics. In spite of great interest in this technology due to their affordability and robustness, there is a lack of scientific basis for process understanding and many technical challenges still remain. The influence of perform properties and other parameters on the resulting microstructure and properties of final material is not well understood. In this presentation, mechanism of silicon-carbon reaction in various systems and the effect of perform microstructure on the mechanical properties of advanced silicon carbide based materials will be discussed. Various examples of applications of reactively processed advanced silicon carbide ceramics and composite materials will be presented.

  8. Thermo-tunable hybrid photonic crystal fiber based on solution-processed chalcogenide glass nanolayers

    DEFF Research Database (Denmark)

    Markos, Christos

    2016-01-01

    the air-capillaries of the fiber based on a solution-processed glass approach. The deposited high-index layers revealed antiresonant transmission windows from similar to 500 nm up to similar to 1300 nm. We experimentally demonstrate for the first time the possibility to thermally-tune the revealed....../degrees C at 1300 nm. The proposed fiber device could potentially constitute an efficient route towards realization of monolithic tunable fiber filters or sensing elements....

  9. Correlations in photon-numbers and integrated intensities in parametric processes involving three optical fields

    Czech Academy of Sciences Publication Activity Database

    Peřina, Jan; Křepelka, Jaromír; Peřina ml., Jan; Bondani, M.; Allevi, A.; Andreoni, A.

    2009-01-01

    Roč. 53, č. 3 (2009), 373-382 ISSN 1434-6060 R&D Projects: GA AV ČR KAN301370701; GA MŠk(CZ) 1M06002 Institutional research plan: CEZ:AV0Z10100522 Keywords : parametric process * three-mode state * sub-Poisson statistics * conditional measurement Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.420, year: 2009

  10. Nonlinear dispersion-based incoherent photonic processing for microwave pulse generation with full reconfigurability.

    Science.gov (United States)

    Bolea, Mario; Mora, José; Ortega, Beatriz; Capmany, José

    2012-03-12

    A novel all-optical technique based on the incoherent processing of optical signals using high-order dispersive elements is analyzed for microwave arbitrary pulse generation. We show an approach which allows a full reconfigurability of a pulse in terms of chirp, envelope and central frequency by the proper control of the second-order dispersion and the incoherent optical source power distribution, achieving large values of time-bandwidth product.

  11. Ionization of a cesium atom by an absorption process involving two photons from a laser beam; Ionisation d'un atome de cesium par un processus d'absorption a deux photons issus d'un faisceau laser

    Energy Technology Data Exchange (ETDEWEB)

    Gontier, Y; Trahin, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-01-01

    The expression giving the ionisation cross-section of an atom, by an absorption process involving two photons produced from a laser beam, is derived. The non-relativistic case is considered and the dipolar approximation used. The summation over the intermediate states is carried out rigorously by means of a special technique which is described in detail. A method is presented which makes it possible to obtain the numerical solution. (authors) [French] La formule donnant la section efficace d'ionisation d'un atome, par un processus d'absorption mettant en jeu deux photons issus d'un faiseau Laser, est etablie. On se place dans le cas non relativiste et Pon utilise l'approximation dipolaire. La sommation sur les etats intermediaires est effectuee rigoureusement au moyen d'une technique particuliere qui est decrite en detail. On expose une methode permettant d'obtenir la solution numerique. (auteurs)

  12. Accelerating Monte Carlo simulations of photon transport in a voxelized geometry using a massively parallel graphics processing unit

    International Nuclear Information System (INIS)

    Badal, Andreu; Badano, Aldo

    2009-01-01

    Purpose: It is a known fact that Monte Carlo simulations of radiation transport are computationally intensive and may require long computing times. The authors introduce a new paradigm for the acceleration of Monte Carlo simulations: The use of a graphics processing unit (GPU) as the main computing device instead of a central processing unit (CPU). Methods: A GPU-based Monte Carlo code that simulates photon transport in a voxelized geometry with the accurate physics models from PENELOPE has been developed using the CUDA programming model (NVIDIA Corporation, Santa Clara, CA). Results: An outline of the new code and a sample x-ray imaging simulation with an anthropomorphic phantom are presented. A remarkable 27-fold speed up factor was obtained using a GPU compared to a single core CPU. Conclusions: The reported results show that GPUs are currently a good alternative to CPUs for the simulation of radiation transport. Since the performance of GPUs is currently increasing at a faster pace than that of CPUs, the advantages of GPU-based software are likely to be more pronounced in the future.

  13. Fully Integrated Linear Single Photon Avalanche Diode (SPAD) Array with Parallel Readout Circuit in a Standard 180 nm CMOS Process

    Science.gov (United States)

    Isaak, S.; Bull, S.; Pitter, M. C.; Harrison, Ian.

    2011-05-01

    This paper reports on the development of a SPAD device and its subsequent use in an actively quenched single photon counting imaging system, and was fabricated in a UMC 0.18 μm CMOS process. A low-doped p- guard ring (t-well layer) encircling the active area to prevent the premature reverse breakdown. The array is a 16×1 parallel output SPAD array, which comprises of an active quenched SPAD circuit in each pixel with the current value being set by an external resistor RRef = 300 kΩ. The SPAD I-V response, ID was found to slowly increase until VBD was reached at excess bias voltage, Ve = 11.03 V, and then rapidly increase due to avalanche multiplication. Digital circuitry to control the SPAD array and perform the necessary data processing was designed in VHDL and implemented on a FPGA chip. At room temperature, the dark count was found to be approximately 13 KHz for most of the 16 SPAD pixels and the dead time was estimated to be 40 ns.

  14. Accelerating Monte Carlo simulations of photon transport in a voxelized geometry using a massively parallel graphics processing unit

    Energy Technology Data Exchange (ETDEWEB)

    Badal, Andreu; Badano, Aldo [Division of Imaging and Applied Mathematics, OSEL, CDRH, U.S. Food and Drug Administration, Silver Spring, Maryland 20993-0002 (United States)

    2009-11-15

    Purpose: It is a known fact that Monte Carlo simulations of radiation transport are computationally intensive and may require long computing times. The authors introduce a new paradigm for the acceleration of Monte Carlo simulations: The use of a graphics processing unit (GPU) as the main computing device instead of a central processing unit (CPU). Methods: A GPU-based Monte Carlo code that simulates photon transport in a voxelized geometry with the accurate physics models from PENELOPE has been developed using the CUDA programming model (NVIDIA Corporation, Santa Clara, CA). Results: An outline of the new code and a sample x-ray imaging simulation with an anthropomorphic phantom are presented. A remarkable 27-fold speed up factor was obtained using a GPU compared to a single core CPU. Conclusions: The reported results show that GPUs are currently a good alternative to CPUs for the simulation of radiation transport. Since the performance of GPUs is currently increasing at a faster pace than that of CPUs, the advantages of GPU-based software are likely to be more pronounced in the future.

  15. Accelerating Monte Carlo simulations of photon transport in a voxelized geometry using a massively parallel graphics processing unit.

    Science.gov (United States)

    Badal, Andreu; Badano, Aldo

    2009-11-01

    It is a known fact that Monte Carlo simulations of radiation transport are computationally intensive and may require long computing times. The authors introduce a new paradigm for the acceleration of Monte Carlo simulations: The use of a graphics processing unit (GPU) as the main computing device instead of a central processing unit (CPU). A GPU-based Monte Carlo code that simulates photon transport in a voxelized geometry with the accurate physics models from PENELOPE has been developed using the CUDATM programming model (NVIDIA Corporation, Santa Clara, CA). An outline of the new code and a sample x-ray imaging simulation with an anthropomorphic phantom are presented. A remarkable 27-fold speed up factor was obtained using a GPU compared to a single core CPU. The reported results show that GPUs are currently a good alternative to CPUs for the simulation of radiation transport. Since the performance of GPUs is currently increasing at a faster pace than that of CPUs, the advantages of GPU-based software are likely to be more pronounced in the future.

  16. Sustainable chemical processing and energy-carbon dioxide management: review of challenges and opportunities

    DEFF Research Database (Denmark)

    Frauzem, Rebecca; Vooradi, Ramsagar; Bertran, Maria-Ona

    2018-01-01

    This paper presents a brief review of the available energy sources for consumption, their effects in terms of CO2-emission and its management, and sustainable chemical processing where energy-consumption, CO2-emission, as well as economics and environmental impacts are considered. Not all available...... energy sources are being utilized efficiently, while, the energy source causing the largest emission of CO2 is being used in the largest amount. The CO2 management is therefore looking at "curing" the problem rather than "preventing" it. Examples highlighting the synthesis, design and analysis...... of sustainable chemical processing in the utilization of biomass-based energy-chemicals production, carbon-capture and utilization with zero or negative CO2-emission to produce value added chemicals as well as retrofit design of energy intensive chemical processes with significant reduction of energy consumption...

  17. Opportunities for membrane technologies in the treatment of mining and mineral process streams and effluents

    International Nuclear Information System (INIS)

    Awadalla, F.T.; Kumar, A.

    1994-01-01

    The membrane separation technologies of microfiltration, ultrafiltration, nanofiltration, and reverse osmosis are suitable for treating many dilute streams and effluents generated in mining and mineral processing. Membrane technologies are capable of treating these dilute streams in order to produce clean permeate water for recycle and a concentrate that can potentially be used for valuable metals recovery. Membrane technologies can be utilized alone, or in combination with other techniques as a polishing step, in these separation processes. A review of potential applications of membranes for the treatment of different process streams and effluents for water recycling and pollution control is given here. Although membranes may not be optimum in all applications, these technologies are recognized in the mining sector for the many potential advantages they can provide. 59 refs

  18. Generation of photon number states

    International Nuclear Information System (INIS)

    Waks, Edo; Diamanti, Eleni; Yamamoto, Yoshihisa

    2006-01-01

    The visible light photon counter (VLPC) has the capability to discriminate photon number states, in contrast to conventional photon counters which can only detect the presence or absence of photons. We use this capability, along with the process of parametric down-conversion, to generate photon number states. We experimentally demonstrate generation of states containing 1, 2, 3 and 4 photons with high fidelity. We then explore the effect the detection efficiency of the VLPC has on the generation rate and fidelity of the created states

  19. Duration of suicide process among suicide attempters and characteristics of those providing window of opportunity for intervention

    Directory of Open Access Journals (Sweden)

    Shivanand Kattimani

    2016-01-01

    Full Text Available Background: There is limited cross-cultural literature on the duration of suicide process among attempters. Aims: The primary aim was to assess the duration of suicide process among suicide attempters attending the Crisis Intervention Clinic. We also aimed to identify the characteristics of those who reported a longer duration for this process. Methods: In this retrospective record-based study, we collected the duration of the suicidal process from the records of all the suicide attempters evaluated over a 3-year period (n = 319. Attempters were divided into four groups based on the quartile value of the duration of the suicidal process. For analysis, the characteristics of those in the last quartile with suicide process time of >120 min (n = 75 were compared with those in the first three (n = 244. Those in the last quartile were considered to provide a window of opportunity for intervention. Results: The median time for the suicidal process was 30 min (interquartile range of 5 min to 120 min. Seventy-five (23.5% subjects belonged to the fourth quartile (duration of suicide process >120 min. A significant proportion of them came from urban areas (P = 0.011, had a diagnosis of mood disorder (P = 0.028, had visited a health professional in the recent past (P = 0.015, and had lower rates of attempt under intoxication (P = 0.005. A lesser proportion of them showed problem-focused disengagement style of coping strategy (P = 0.015. Conclusions: The suicide process time among Indian suicide attempters is short. However, a quarter of them has suicide process duration of 2 h which provides some scope for intervention. Individual and community level interventions need further evaluation for their potential efficacy in preventing the progress of the suicidal process.

  20. Characterization of the Photon Counting CHASE Jr., Chip Built in a 40-nm CMOS Process With a Charge Sharing Correction Algorithm Using a Collimated X-Ray Beam

    Energy Technology Data Exchange (ETDEWEB)

    Krzyżanowska, A. [AGH-UST, Cracow; Deptuch, G. W. [Fermilab; Maj, P. [AGH-UST, Cracow; Gryboś, P. [AGH-UST, Cracow; Szczygieł, R. [AGH-UST, Cracow

    2017-08-01

    This paper presents the detailed characterization of a single photon counting chip, named CHASE Jr., built in a CMOS 40-nm process, operating with synchrotron radiation. The chip utilizes an on-chip implementation of the C8P1 algorithm. The algorithm eliminates the charge sharing related uncertainties, namely, the dependence of the number of registered photons on the discriminator’s threshold, set for monochromatic irradiation, and errors in the assignment of an event to a certain pixel. The article presents a short description of the algorithm as well as the architecture of the CHASE Jr., chip. The analog and digital functionalities, allowing for proper operation of the C8P1 algorithm are described, namely, an offset correction for two discriminators independently, two-stage gain correction, and different operation modes of the digital blocks. The results of tests of the C8P1 operation are presented for the chip bump bonded to a silicon sensor and exposed to the 3.5- μm -wide pencil beam of 8-keV photons of synchrotron radiation. It was studied how sensitive the algorithm performance is to the chip settings, as well as the uniformity of parameters of the analog front-end blocks. Presented results prove that the C8P1 algorithm enables counting all photons hitting the detector in between readout channels and retrieving the actual photon energy.

  1. Dynamical Evolution of Properties for Atom and Field in the Process of Two-Photon Absorption and Emission Between Atomic Levels

    Science.gov (United States)

    Wang, Jian-ming; Xu, Xue-xiang

    2018-04-01

    Using dressed state method, we cleverly solve the dynamics of atom-field interaction in the process of two-photon absorption and emission between atomic levels. Here we suppose that the atom is initially in the ground state and the optical field is initially in Fock state, coherent state or thermal state, respectively. The properties of the atom, including the population in excited state and ground state, the atom inversion, and the properties for optical field, including the photon number distribution, the mean photon number, the second-order correlation function and the Wigner function, are discussed in detail. We derive their analytical expressions and then make numerical analysis for them. In contrast with Jaynes-Cummings model, some similar results, such as quantum Rabi oscillation, revival and collapse, are also exhibit in our considered model. Besides, some novel nonclassical states are generated.

  2. Method for identifying process reuse opportunities to enhance the operating model

    CSIR Research Space (South Africa)

    De Vries, M

    2011-12-01

    Full Text Available the volatility of strategy and suggests the use of an operating model (OM), which is a commitment to a way of doing business. The OM creates a company-wide vision for process standardization and data centralization and guides decisions about how a company...

  3. Polarized triple-collinear splitting functions at NLO for processes with photons

    International Nuclear Information System (INIS)

    Sborlini, Germán F.R.; Florian, Daniel de; Rodrigo, Germán

    2015-01-01

    We compute the polarized splitting functions in the triple collinear limit at next-to-leading order accuracy (NLO) in the strong coupling α_S, for the splitting processes γ→qq-barγ, γ→qq-barg and g→qq-barγ. The divergent structure of each splitting function was compared to the predicted behaviour according to Catani’s formula. The results obtained in this paper are compatible with the unpolarized splitting functions computed in a previous article. Explicit results for NLO corrections are presented in the context of conventional dimensional regularization (CDR).

  4. Polarized triple-collinear splitting functions at NLO for processes with photons

    Energy Technology Data Exchange (ETDEWEB)

    Sborlini, Germán F.R. [Departamento de Física and IFIBA, FCEyN, Universidad de Buenos Aires (1428) Pabellón 1 Ciudad Universitaria, Capital Federal (Argentina); Instituto de Física Corpuscular, Universitat de València,Consejo Superior de Investigaciones Científicas,Parc Científic, E-46980 Paterna, Valencia (Spain); Florian, Daniel de [Departamento de Física and IFIBA, FCEyN, Universidad de Buenos Aires (1428) Pabellón 1 Ciudad Universitaria, Capital Federal (Argentina); Rodrigo, Germán [Instituto de Física Corpuscular, Universitat de València,Consejo Superior de Investigaciones Científicas,Parc Científic, E-46980 Paterna, Valencia (Spain)

    2015-03-04

    We compute the polarized splitting functions in the triple collinear limit at next-to-leading order accuracy (NLO) in the strong coupling α{sub S}, for the splitting processes γ→qq-barγ, γ→qq-barg and g→qq-barγ. The divergent structure of each splitting function was compared to the predicted behaviour according to Catani’s formula. The results obtained in this paper are compatible with the unpolarized splitting functions computed in a previous article. Explicit results for NLO corrections are presented in the context of conventional dimensional regularization (CDR).

  5. Tests of perturbative quantum chromodynamics in photon-photon collisions

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1979-01-01

    The production of hadrons in the collision of two photons via the process e + e - → e + e - X can provide an ideal laboratory for testing many of the features of the photon's hadronic interactions, especially its short-distance aspects. That part of two-photon physics which is particularly relevant to tests of perturbative QCD is reviewed here. 6 figures

  6. One-photon two-electron processes in helium: Unity and diversity

    International Nuclear Information System (INIS)

    Bouri, C.; Selles, P.; Malegat, L.; Kwato Njock, M.G.

    2007-01-01

    The ab initio HRM-SOW method has established itself as the ideally fit tool to explore the three-body dynamics of the helium atom close to its full break-up threshold. Accordingly, it is used here to perform a 'numerical experiment' designed to enlighten the relations between the various competing processes which may occur in the vicinity of the double ionization threshold, be it double excitation, excitation-ionization, or double ionization. More precisely, double ionization and ionization-excitation cross-sections are produced at 100 meV above the double ionization threshold. The latter, obtained up to as high a level as n=50, are in addition analyzed in terms of spherical and parabolic partial waves in the photo-electron frame. Based on these extensive data, we establish a continuity relation between ionization-excitation and double ionization appropriate to the near threshold region, confirm previous qualitative predictions regarding the dominant angular momentum achieved in these near threshold excitation processes, evidence the relation between ionized-excited and doubly excited states, and promote the partial parabolic ionization-excitation cross-sections as the optimal observation channels of doubly excited states

  7. One-photon two-electron processes in helium: Unity and diversity

    Energy Technology Data Exchange (ETDEWEB)

    Bouri, Celsus [Quantum Optics and Statistics, Institute of Physics, Albert-Ludwigs-Universitaet Freiburg, Hermann-Herder Str.3, D-79104 Freiburg (Germany)]|[LIXAM, Bat. 350, Universite Paris Sud, F-91405 Orsay (France)]|[CEPAMOQ, Universite de Douala, B.P. 8580, Douala (Cameroon); Malegat, Laurence; Selles, Patricia [LIXAM, Bat. 350, Universite Paris Sud, F-91405 Orsay (France); Njock, Moise Kwato [CEPAMOQ, Universite de Douala, B.P. 8580, Douala (Cameroon)

    2008-07-01

    The ab-initio HRM-SOW method has established itself as the ideally fit tool to explore the three-body dynamics of the helium atom close to the three-body break-up threshold. Accordingly, it is used here to perform a numerical experiment designed to enlighten the relation between the various competing processes which may occur in the vicinity of the double ionization threshold, be it double excitation, excitation-ionization or double ionization. More precisely, double ionization and ionization-excitation cross sections are produced at 100 meV above the double ionization threshold. The latter, obtained up to as high a level as n=50, are in addition analyzed in terms of spherical and parabolic partial waves in the photoelectron frame. Based on these extensive data, we establish a continuity relation between ionization-excitation and double ionization appropriate to the near threshold, confirm previous qualitative predictions regarding the dominant angular momentum achieved in these near threshold excitation processes, evidence the relation between ionized-excited and doubly excited states, and promote the partial parabolic ionization-excitation cross sections as the optimal observation channels of doubly excited states.

  8. One-photon two-electron processes in helium: Unity and diversity

    Energy Technology Data Exchange (ETDEWEB)

    Bouri, C.; Selles, P. [LIXAM et Federation LUMAT, CNRS et Universite Paris-Sud 11, 91405 Orsay (France); Malegat, L. [LIXAM et Federation LUMAT, CNRS et Universite Paris-Sud 11, 91405 Orsay (France)], E-mail: Laurence.Malegat@lixam.u-psud.fr; Kwato Njock, M.G. [CEPAMOQ, Faculty of Science, University of Douala, P.O. Box 8580, Douala (Cameroon)

    2007-10-15

    The ab initio HRM-SOW method has established itself as the ideally fit tool to explore the three-body dynamics of the helium atom close to its full break-up threshold. Accordingly, it is used here to perform a 'numerical experiment' designed to enlighten the relations between the various competing processes which may occur in the vicinity of the double ionization threshold, be it double excitation, excitation-ionization, or double ionization. More precisely, double ionization and ionization-excitation cross-sections are produced at 100 meV above the double ionization threshold. The latter, obtained up to as high a level as n=50, are in addition analyzed in terms of spherical and parabolic partial waves in the photo-electron frame. Based on these extensive data, we establish a continuity relation between ionization-excitation and double ionization appropriate to the near threshold region, confirm previous qualitative predictions regarding the dominant angular momentum achieved in these near threshold excitation processes, evidence the relation between ionized-excited and doubly excited states, and promote the partial parabolic ionization-excitation cross-sections as the optimal observation channels of doubly excited states.

  9. Ultra-weak photon emission as a non-invasive tool for monitoring of oxidative processes in the epidermal cells of human skin: comparative study on the dorsal and the palm side of the hand.

    Science.gov (United States)

    Rastogi, Anshu; Pospísil, Pavel

    2010-08-01

    All living organisms emit spontaneous ultra-weak photon emission as a result of cellular metabolic processes. Exposure of living organisms to exogenous factors results in oxidative processes and enhancement in ultra-weak photon emission. Here, hydrogen peroxide (H(2)O(2)), as a strongly oxidizing molecule, was used to induce oxidative processes and enhance ultra-weak photon emission in human hand skin. The presented work intends to compare both spontaneous and peroxide-induced ultra-weak photon emission from the epidermal cells on the dorsal and the palm side of the hand. A highly sensitive photomultiplier tube and a charge-coupled device camera were used to detect ultra-weak photon emission from human hand skin. Spontaneous ultra-weak photon emission from the epidermal cells on the dorsal side of the hand was 4 counts/s. Topical application of 500 mM H(2)O(2) to the dorsal side of the hand caused enhancement in ultra-weak photon emission to 40 counts/s. Interestingly, both spontaneous and peroxide-induced ultra-weak photon emission from the epidermal cells on the palm side of the hand were observed to increase twice their values, i.e. 8 and 80 counts/s, respectively. Similarly, the two-dimensional image of ultra-weak photon emission observed after topical application of H(2)O(2) to human skin reveals that photon emission from the palm side exceeds the photon emission from the dorsal side of the hand. The results presented indicate that the ultra-weak photon emission originating from the epidermal cells on the dorsal and the palm side of the hand is related to the histological structure of the human hand skin. Ultra-weak photon emission is shown as a non-destructive technique for monitoring of oxidative processes in the epidermal cells of the human hand skin and as a diagnostic tool for skin diseases.

  10. Improving the Timeliness of Equal Employment Opportunity Complaint Processing in Department of Defense

    Science.gov (United States)

    2015-01-01

    1964 (Title VII) and the Pregnancy Discrimination Act amendment to Title VII, the Equal Pay Act of 1963, the Age Discrimi- nation in Employment Act of...Act of 1964 (Title VII) and the Pregnancy Discrimination Act amendment to Title VII, the Equal Pay Act of 1963, the Age Discrimination in...EEO programs uti - lize training on the EEO complaint process and framing of claims and that they use more-structured investigation requests

  11. Opportunities and applications of medical imaging and image processing techniques for nondestructive testing

    International Nuclear Information System (INIS)

    Song, Samuel Moon Ho; Cho, Jung Ho; Son, Sang Rock; Sung, Je Jonng; Ahn, Hyung Keun; Lee, Jeong Soon

    2002-01-01

    Nondestructive testing (NDT) of structures strives to extract all relevant data regarding the state of the structure without altering its form or properties. The success enjoyed by imaging and image processing technologies in the field of modem medicine forecasts similar success of image processing related techniques both in research and practice of NDT. In this paper, we focus on two particular instances of such applications: a modern vision technique for 3-D profile and shape measurement, and ultrasonic imaging with rendering for 3-D visualization. Ultrasonic imaging of 3-D structures for nondestructive evaluation purposes must provide readily recognizable 3-D images with enough details to clearly show various faults that may or may not be present. As a step towards Improving conspicuity and thus detection of faults, we propose a pulse-echo ultrasonic imaging technique to generate a 3-D image of the 3-D object under evaluation through strategic scanning and processing of the pulse-echo data. This three-dimensional processing and display improves conspicuity of faults and in addition, provides manipulation capabilities, such as pan and rotation of the 3-D structure. As a second application, we consider an image based three-dimensional shape determination system. The shape, and thus the three-dimensional coordinate information of the 3-D object, is determined solely from captured images of the 3-D object from a prescribed set of viewpoints. The approach is based on the shape from silhouette (SFS) technique and the efficacy of the SFS method is tested using a sample data set. This system may be used to visualize the 3-D object efficiently, or to quickly generate initial CAD data for reverse engineering purposes. The proposed system potentially may be used in three dimensional design applications such as 3-D animation and 3-D games.

  12. A consortium approach to competency-based undergraduate medical education in Uganda: process, opportunities and challenges.

    Science.gov (United States)

    Kiguli, Sarah; Mubuuke, Roy; Baingana, Rhona; Kijjambu, Stephen; Maling, Samuel; Waako, Paul; Obua, Celestino; Ovuga, Emilio; Kaawa-Mafigiri, David; Nshaho, Jonathan; Kiguli-Malwadde, Elsie; Bollinger, Robert; Sewankambo, Nelson

    2014-01-01

    Uganda, like the rest of Africa, is faced with serious health challenges including human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS), other infectious diseases and increasing non-communicable diseases, yet it has a significant shortage of health workers. Even the few health workers available may lack desired competencies required to address current and future health challenges. Reducing Uganda's disease burden and addressing health challenges requires Ugandan medical schools to produce health workers with the necessary competencies. This study describes the process which a consortium of Ugandan medical schools and the Medical Education Partnership for Equitable Services to all Ugandans (MESAU) undertook to define the required competencies of graduating doctors in Uganda and implement competency-based medical education (CBME). A retrospective qualitative study was conducted in which document analysis was used to collect data employing pre-defined checklists, in a desktop or secondary review of various documents. These included reports of MESAU meetings and workshops, reports from individual institutions as well as medical undergraduate curricula of the different institutions. Thematic analysis was used to extract patterns from the collected data. MESAU initiated the process of developing competencies for medical graduates in 2011 using a participatory approach of all stakeholders. The process involved consultative deliberations to identify priority health needs of Uganda and develop competencies to address these needs. Nine competence domain areas were collaboratively identified and agreed upon, and competencies developed in these domains. Key successes from the process include institutional collaboration, faculty development in CBME and initiating the implementation of CBME. The consortium approach strengthened institutional collaboration that led to the development of common competencies desired of all medical graduates to

  13. Energy efficiency opportunities in the production process of cast iron foundries: An experience in Italy

    International Nuclear Information System (INIS)

    Lazzarin, Renato M.; Noro, Marco

    2015-01-01

    Foundry sector is one of the most energy intensive in industry. Energy audits performed in 5 Italian cast iron foundries allowed to identify energy utilization in the various processes that from the melting of the iron arrive at the finishing of the casting. Main equipment was surveyed, evaluating the influence on the overall energy consumption, producing a detailed analysis of energy use per department and energy performance indexes. A separate study was carried out for foundries with induction furnaces and cold or hot blast cupolas. Possibilities of heat recovery was identified particularly in combustion air preheating, but also for building heating or to power direct cycles to produce electricity. Better insulation and new insulating materials can improve the efficiency and the quality of the processes. Suggestions are supplied in the various foundry departments for energy saving. Possible energy saving actions on the service plants will be dealt with in a separate paper. - Highlights: • The Authors performed energy audits in 5 Italian cast iron foundries. • Main equipment was surveyed, evaluating the influence on the overall energy consumption. • An analysis of energy use per department and energy performance indexes was performed. • Possibilities of heat recovery were identified in combustion air preheating and for building heating. • Better and new insulating materials were analyzed to improve the efficiency and process quality.

  14. Stakeholder consultations and opportunities for integrating socio-behavioural factors into the pesticide risk analysis process.

    Science.gov (United States)

    Calliera, Maura; Marchis, Alex; Sacchettini, Gabriele; Capri, Ettore

    2016-02-01

    The pesticide risk analysis process is well regulated in the EU, especially in relation to placing on the market authorisation procedures, but in order to avoid risks for human health and environment in the use phase, information on how these substances are employed and on socio-behavioural factors that can influence the exposure have to be taken into account. To better explore reasons about the gap between risk assessment and risk management, within the EU FP7 Health and Environmental Risks: Organisation, Integration and Cross-fertilisation of Scientific Knowledge (HEROIC) project, a stepwise stakeholder's consultation process was developed using a mixed approach in two different phases (survey and roundtable). We elicited stakeholder views regarding factors that could limit the pesticide risk assessment phase linked on how the knowledge is produced and the way the data are used in risk management and in risk communication, also taking into account qualitative factors such as responsibility, trust and behaviours, which could have impact on risk assessment policies. Activities deployed indicate that some changes and interaction are needed to better define the problems at the formulation stage, and the type of information risk assessor has to provide, to better inform risk manager in addressing different societal needs, to strengthen the credibility of the process of risk assessment and improve the effectiveness of policies. Integrations between disciplines may initially increase the complexity but in turn will provide a better and more useful estimation of the risk, reinforce transparency and drive a more efficient use of risk management resources.

  15. New production processes for alpha hemihydrate open up new marketing opportunities

    International Nuclear Information System (INIS)

    Engert, W.; Lehmkaemper, O.; Bunte, H.P.

    1991-01-01

    New production processes and markets for alpha hemihydrate are discussed. Utility studies concluded that lignite gypsum is harmless in terms of public and occupational health, and is technically comparable to or superior to natural gypsum by virtue of greater purity. Semi-commercial and pilot-scale studies were carried out on the use of flue gas desulfurization (FGD) gypsum for producing alpha hemihydrate, with successful results. The process enabled pure alpha hemihydrate to be produced without dihydrate or dihydrate impurities, and of a constant, uniform quality. The treatment consists of forming pressed mouldings of FGD gypsum followed by steam autoclaving, drying and milling. Agents are used to stabilize the stackable moldings, and to act as growth inhibitors during transformation of dihydrite to alpha-hemihydrate. Markets for the product are found in mining, tunneling and road building, foundation work, floor systems, as hard plaster for dental and moulding applications, for construction industry use, and as structural and non-structural material. Details are presented of the production process and marketing concepts. 12 figs

  16. An assessment on the recycling opportunities of wastes emanating from scrap metal processing in Mauritius

    Energy Technology Data Exchange (ETDEWEB)

    Mauthoor, Sumayya, E-mail: sumayya.mauthoor@umail.uom.ac.mu [Department of Chemical and Environmental Engineering, University of Mauritius, Réduit (Mauritius); Mohee, Romeela [Professor of Chemical and Environmental Engineering, National Research Chair in Solid Waste Management, Mauritius Research Council (Mauritius); Kowlesser, Prakash [Solid Waste/Beach Management Unit, Ministry of Local Government and Outer Islands (Mauritius)

    2014-10-15

    Highlights: • Scrap metal processing wastes. • Areas of applications for slag, electric arc furnace dust, mill scale and wastewater sludge. • Waste generation factor of 349.3 kg per ton of steel produced. • Waste management model. - Abstract: This paper presents an assessment on the wastes namely slag, dust, mill scale and sludge resulting from scrap metal processing. The aim of this study is to demonstrate that there are various ways via which scrap metal processing wastes can be reused or recycled in other applications instead of simply diverting them to the landfill. These wastes are briefly described and an overview on the different areas of applications is presented. Based on the results obtained, the waste generation factor developed was 349.3 kg per ton of steel produced and it was reported that slag represents 72% of the total wastes emanating from the iron and steel industry in Mauritius. Finally the suitability of the different treatment and valorisation options in the context of Mauritius is examined.

  17. All-Optical Signal processing using Highly Nonlinear Photonic Crystal Fiber

    DEFF Research Database (Denmark)

    Andersen, Peter Andreas

    2006-01-01

    -optical regeneration is the only possible way of regenerating a signal with the current technology. Transforming the current telecommunication network into an all-optical network will require an all-optical regeneration of the optical signal. At the current time (May 2005) all-optical regeneration is a tool only used......The use of HNL-PCF in optical communication systems has been investigated in this thesis. The investigation has been done with respect to the future of telecommunications in an all-optical system. The PCFs used have all been used for all-optical signal processing as part of an optical component...... and the possibility of large differences between the refractive indices of the core and the cladding by using air-holes, makes PCFs suited for custom made components. By testing a HNL-PCF as a medium for supercontinuum generation at various dispersion values and at the same time using that supercontinuum...

  18. Recent developments in the theory of photon-photon collisions

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1984-09-01

    Over the past few years the field of photon-photon collisions has emerged as one of the best testing grounds for QCD, particularly in the area of exclusive and inclusive hard scattering processes, exotic resonance production, and detailed tests of the coupling of real and virtual photons to the quark current. In this summary of contributed papers, I will briefly review recent theoretical progress in the analysis of two-photon reactions and possible directions for future work. 29 references

  19. Uranium extraction from phosphates: Background, opportunities, process overview and way forward for commercialisation

    International Nuclear Information System (INIS)

    Haldar, T.K.; Hilton, J.; Tulsidas, H.

    2014-01-01

    Socio-economic up-gradation for major part of global population, particularly in developing countries will call for large growth of electricity demand. The fact that 2 billion of world’s 7 billion population do not have access to electricity justifies this growth projection. Environmental concern along with increasing demand for other essential ingredients for improved standard of living like affordable food, water, healthcare etc. will encourage large growth in nuclear technology utilisation. While conventional uranium resources will continue to be the major source for meeting the resultant surge in uranium demand, there is a need to look forward beyond this. Inherent advantage of uranium extraction from phosphate (UxP) is that it is the by-product of phosphate fertilizer industry. There is no need for separate mine development, ore processing or tailing disposal. Feed phosphoric acid is available from phosphate industry in ready to use condition. UxP thus enables recovery of energy resource otherwise lost for ever besides making the fertiliser cleaner. UxP has also potential to make phosphate industry economically more viable and socially more acceptable. Phosphate industry also benefits from cleaner return acid making operation of downstream plant simpler and cleaner besides possible value addition of the product basket Due to low uranium concentration in source material, normally in the range of 80 – 150 ppm, and several process and engineering issues inherent to this relatively difficult separation process, large scale commercial deployment will depend on development of commercially viable technology. Though the process has been utilised for production of uranium in the past, before setting up a new commercial facility, it is imperative that its techno-economic feasibility be established considering all related aspects of the proposed facility. This will address the difficulties encountered in earlier plants, problems related to wide variation in physical

  20. Optimization of photonic crystal cavities

    DEFF Research Database (Denmark)

    Wang, Fengwen; Sigmund, Ole

    2017-01-01

    We present optimization of photonic crystal cavities. The optimization problem is formulated to maximize the Purcell factor of a photonic crystal cavity. Both topology optimization and air-hole-based shape optimization are utilized for the design process. Numerical results demonstrate...... that the Purcell factor of the photonic crystal cavity can be significantly improved through optimization....

  1. POWER EFFICIENCY OPPORTUNITIES FOR INDUSTRIAL REFRIGERATION SYSTEM OF FOOD PROCESSING ENTERPRISE

    Directory of Open Access Journals (Sweden)

    O. Ostapenko

    2016-12-01

    Full Text Available Rising prices on power supply are forcing business owners to search the ways of operating costs reducing. Refrigeration system in the food industry is a major source of power consumption. The utilization of cold accumulation systems allows reducing of refrigeration unit power consumption. In this paper the refrigeration system with a system of cold accumulation and dry cooling tower is considered. The possibility of power consumption reducing due to the organization of the enterprise refrigeration system operation process in the night period according to electricity multiple tariffs has been analyzed.

  2. Photon-induced Processing of Interstellar Ices in the Laboratory. Focus on Their Non-thermal Desorption.

    Science.gov (United States)

    Martin-Domenech, Rafael; Munoz Caro, Guillermo; Cruz-Diaz, Gustavo A.; Oberg, Karin I.

    2018-06-01

    Some of the processes that take place in the interstellar medium (ISM)can be simulated in laboratories on Earth under astrophysically relevant conditions. For example, the energetic processing of the ice mantles that accrete on top of dust grains in the coldest regions of the ISM, leading to the production of new species and their desorption to the gas phase. In particular, observation of complex organic molecules (COMs) in cold interstellar environments stress the need for not only a solid state formation but also for non-thermal desorption mechanisms that can account for the observed abundances in regions where thermal desorption is inhibited. Laboratory Astrophysics can be used to test different non-thermal desorption processes and extract yields than can be extrapolated to the astrophysical scenario with theoretical models. 0th generation COMs like CH3OH and H2CO can be formed at very low temperatures. In this talk, we present laboratory simulations of the UV photoprocessing of a binary ice mixture composed by water (the main component of astrophysical ices) and methane. Formation of CO, CO2, CH3OH and H2CO was confirmed by IR spectroscopy and subsequent TPD. At the same time, photodesorption of CO and H2CO was detected by means of a Quadrupole Mass Spectrometer, with yields on the order of 10-4 and 10-5 molecules per incident photon, respectively. In general, photodesorption can take place through a direct mechanism, where the absorbing molecule (or its photofragments) are desorbed; or through an indirect mechanism where the absorbed energy is transferred to a surface molecule which is the one finally desorbing. In the case of photoproducts, the evolution of the photodesorption yield gives information on the photodesorption mechanism: a constant photodesorption yield is observed when the photoproducts are desorbed right after their formation; while an increasing yield is measured when the photoproducts are desorbed later after energy transfer from another

  3. Energy audit and conservation opportunities for pyroprocessing unit of a typical dry process cement plant

    International Nuclear Information System (INIS)

    Kabir, G.; Abubakar, A.I.; El-Nafaty, U.A.

    2010-01-01

    Cement production process has been highly energy and cost intensive. The cement plant requires 8784 h per year of the total operating hours to produce 640,809 tonnes of clinker. To achieve effective and efficient energy management scheme, thermal energy audit analysis was employed on the pyroprocessing unit of the cement plant. Fuel combustion generates the bulk of the thermal energy for the process, amounting to 95.48% (4164.02 kJ/kg cl ) of the total thermal energy input. Thermal efficiency of the unit stands at 41%, below 50-54% achieved in modern plants. The exhaust gases and kiln shell heat energy losses are in significant quantity, amounting to 27.9% and 11.97% of the total heat input respectively. To enhance the energy performance of the unit, heat losses conservation systems are considered. Waste heat recovery steam generator (WHRSG) and Secondary kiln shell were studied. Power and thermal energy savings of 42.88 MWh/year and 5.30 MW can be achieved respectively. Financial benefits for use of the conservation methods are substantial. Environmental benefit of 14.10% reduction in Greenhouse gases (GHG) emissions could be achieved.

  4. Market Opportunity of Some Aluminium Silicon Alloys Materials through Changing the Casting Process

    Directory of Open Access Journals (Sweden)

    Delfim SOARES

    2012-08-01

    Full Text Available Fatigue is considered to be the most common mechanism by which engineering components fail, and it accounts for at least 90% of all service failures attributed to mechanical causes. Mechanical properties (tensile strength, tensile strain, Young modulus, etc as well as fatigue properties (fatigue life are very dependent on casting method. The most direct effects of casting techniques are on the metallurgical microstructure that bounds the mechanical properties. One of the important variables affected by the casting technique is the cooling rate which is well known to strongly restrict the microstructure. In the present research has been done a comparison of fatigue properties of two aluminum silicon alloys obtained by two casting techniques. It was observed that the fatigue life is increasing with 24% for Al12Si and 31% for AL18Si by using centrifugal casting process instead of gravity casting. This increasing in fatigue life means that a component tailored from materials obtained by centrifugal casting will stay longer in service. It was made an estimation of the time required to recover the costs of technology in order to use the centrifuge process that will allow to obtain materials with improved properties. The amortization can be achieved by using two different marketing techniques: through the release of the product at the old price and with much longer life of the component which means "same price - longer life", or increasing price, by highlighting new product performance which means "higher price - higher properties".

  5. Energy audit and conservation opportunities for pyroprocessing unit of a typical dry process cement plant

    Energy Technology Data Exchange (ETDEWEB)

    Kabir, G.; Abubakar, A.I.; El-Nafaty, U.A. [Chemical Engineering Programme, Abubakar Tafawa Balewa University, P. M. B. 0248, Bauchi (Nigeria)

    2010-03-15

    Cement production process has been highly energy and cost intensive. The cement plant requires 8784 h per year of the total operating hours to produce 640,809 tonnes of clinker. To achieve effective and efficient energy management scheme, thermal energy audit analysis was employed on the pyroprocessing unit of the cement plant. Fuel combustion generates the bulk of the thermal energy for the process, amounting to 95.48% (4164.02 kJ/kg{sub cl}) of the total thermal energy input. Thermal efficiency of the unit stands at 41%, below 50-54% achieved in modern plants. The exhaust gases and kiln shell heat energy losses are in significant quantity, amounting to 27.9% and 11.97% of the total heat input respectively. To enhance the energy performance of the unit, heat losses conservation systems are considered. Waste heat recovery steam generator (WHRSG) and Secondary kiln shell were studied. Power and thermal energy savings of 42.88 MWh/year and 5.30 MW can be achieved respectively. Financial benefits for use of the conservation methods are substantial. Environmental benefit of 14.10% reduction in Greenhouse gases (GHG) emissions could be achieved. (author)

  6. Opportunities for Automated Demand Response in California’s Dairy Processing Industry

    Energy Technology Data Exchange (ETDEWEB)

    Homan, Gregory K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Aghajanzadeh, Arian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); McKane, Aimee [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-08-30

    During periods of peak electrical demand on the energy grid or when there is a shortage of supply, the stability of the grid may be compromised or the cost of supplying electricity may rise dramatically, respectively. Demand response programs are designed to mitigate the severity of these problems and improve reliability by reducing the demand on the grid during such critical times. In 2010, the Demand Response Research Center convened a group of industry experts to suggest potential industries that would be good demand response program candidates for further review. The dairy industry was suggested due to the perception that the industry had suitable flexibility and automatic controls in place. The purpose of this report is to provide an initial description of the industry with regard to demand response potential, specifically automated demand response. This report qualitatively describes the potential for participation in demand response and automated demand response by dairy processing facilities in California, as well as barriers to widespread participation. The report first describes the magnitude, timing, location, purpose, and manner of energy use. Typical process equipment and controls are discussed, as well as common impediments to participation in demand response and automated demand response programs. Two case studies of demand response at dairy facilities in California and across the country are reviewed. Finally, recommendations are made for future research that can enhance the understanding of demand response potential in this industry.

  7. Design of organic 3D microresonators with microfluidics coupled to thin-film processes for photonic applications

    Science.gov (United States)

    Huby, N.; Pluchon, D.; Coulon, N.; Belloul, M.; Moreac, A.; Gaviot, E.; Panizza, P.; Bêche, B.

    2010-06-01

    We report on the design and realization of photonic integrated devices based on 3D organic microresonators (MR) shaped by an applied fluid mechanism technique. Such an interdisciplinary approach has been judiciously achieved by combining microfluidics techniques and thin-film processes, respectively, for the realizations of microfluidic and optical chips. The microfluidic framework with flow rates control allows the fabrication of microresonators with diameters ranging from 30 to 160 μm. The resonance of an isolated sphere in air has been demonstrated by way of a modified Raman spectroscopy devoted to the excitation of Whispering Gallery Modes (WGM). Then the 3D-MR have been integrated onto an organic chip and positioned either close to the extremity of a taper or alongside a rib waveguide. Both devices have proved efficient evanescent coupling mechanisms leading to the excitation of the WGM confined at the surface of the organic 3D-MR. Finally, a band-stop filter has been used to detect the resonance spectra of organic resonators once being integrated. Such spectral resonances have been observed with an integrated configuration and characterized with a Δ λ = 1.4 nm free spectral range (FSR), appearing as stemming from a 78 μm-radius MR structure.

  8. New photonic devices for ultrafast pulse processing operating on the basis of the diffraction-dispersion analogy

    Energy Technology Data Exchange (ETDEWEB)

    Torres-Company, Victor; Minguez-Vega, Gladys; Climent, Vicent; Lands, Jesus [GROC-UJI, Departament de Fisica, Universitat Jaume I, 12080 Castello (Spain); Andres, Pedro [Departament d' Optica, Universitat de Valencia, 46100 Burjassot (Spain)], E-mail: lancis@fca.uji.es

    2008-11-01

    The space-time analogy is a well-known topic within wave optics that brings together some results from beam diffraction and pulse dispersion. On the above basis, and taking as starting point some classical concepts in Optics, several photonic devices have been proposed during the last few years with application in rapidly evolving fields such as ultrafast (femtosecond) optics or RF and microwave signal processing. In this contribution, we briefly review the above ideas with particular emphasis in the generation of trains of ultrafast pulses from periodic modulation of the phase of a CW laser source. This is the temporal analogue of Fresnel diffraction by a pure phase grating. Finally, we extend the analogy to the partially coherent case, what enables us to design an original technique for wavelength-to-time mapping of the spectrum of a temporally stationary source. Results of laboratory experiments concerning the generation of user-defined radio-frequency waveforms and filtering of microwave signals will be shown. The devices are operated with low-cost incoherent sources.

  9. OPPORTUNITY TO REDUCE RESISTANCE TO CHANGE IN A PROCESS OF ORGANIZATIONAL CHANGE

    Directory of Open Access Journals (Sweden)

    Prediscan Mariana

    2011-12-01

    Full Text Available This paper aims to present the research results conducted on several models of organizational change regarding the identification of the appropriate moment in which the managers interest should turn towards the reduction of the employees resistance to change. More specifically, we intend to identify when is the best moment to reduce the resistance to change, depending on the change we want to achieve. After more research of organizational change models, we have reached the following conclusions: -not all models of organizational change present reducing resistance to change as a necessary stage; -the place of this phase in the models of organizational change is not considered to be the same; -some models of organizational change recommend indirectly reducing employee resistance to change by indicating the use of some methods, techniques, processes that would lead to this result. Here we include mainly: communication, training, positive motivation of employees; -we recommended that the place of this stage should vary depending on the desired change to achieve; -in strategic changes, which are extremely important for an organization and which affect a large number of employees, we recommend that the reduction of the employee resistance to change be achieved before passing to the implementation of the plan developed to implement the change; -in imposed changes, in conditions of crisis when we have no time available to plan the change, immediately after it had been implemented it is necessary to conduct effective actions meant to ensure, even if the change has been made, the reduction of the resistance to change of the affected employees -to achieve time savings in the process of organizational change, we recommend that after having obtained a certain attachment of some employees to change, the implementation of the methods, of the techniques that would increase their commitment to continue to be developed in parallel with the implementation of the

  10. Extreme Ultraviolet to Visible Dispersed Single Photon Detection for Highly Sensitive Sensing of Fundamental Processes in Diverse Samples

    Directory of Open Access Journals (Sweden)

    Andreas Hans

    2018-05-01

    Full Text Available The detection of a single photon is the most sensitive method for sensing of photon emission. A common technique for single photon detection uses microchannel plate arrays combined with photocathodes and position sensitive anodes. Here, we report on the combination of such detectors with grating diffraction spectrometers, constituting a low-noise wavelength resolving photon spectroscopy apparatus with versatile applicability. We recapitulate the operation principle of such detectors and present the details of the experimental set-up, which we use to investigate fundamental mechanisms in atomic and molecular systems after excitation with tuneable synchrotron radiation. Extensions for time and polarization resolved measurements are described and examples of recent applications in current research are given.

  11. Laboratory Astrophysics Using High Energy Density Photon and Electron Beams

    CERN Document Server

    Bingham, Robert

    2005-01-01

    The development of intense laser and particle beams has opened up new opportunities to study high energy density astrophysical processes in the Laboratory. With even higher laser intensities possible in the near future vacuum polarization processes such as photon - photon scattering with or without large magnetic fields may also be experimentally observed. In this talk I will review the status of laboratory experiments using intense beans to investigate extreme astrophysical phenomena such as supernovae explosions, gamma x-ray bursts, ultra-high energy cosmic accelerators etc. Just as intense photon or electron beams can excite relativistic electron plasma waves or wakefields used in plasma acceleration, intense neutrino beams from type II supernovae can also excite wakefields or plasma waves. Other instabilities driven by intense beams relevant to perhaps x-ray bursts is the Weibel instability. Simulation results of extreme processes will also be presented.

  12. Future supply chains enabled by continuous processing--opportunities and challenges. May 20-21, 2014 Continuous Manufacturing Symposium.

    Science.gov (United States)

    Srai, Jagjit Singh; Badman, Clive; Krumme, Markus; Futran, Mauricio; Johnston, Craig

    2015-03-01

    This paper examines the opportunities and challenges facing the pharmaceutical industry in moving to a primarily "continuous processing"-based supply chain. The current predominantly "large batch" and centralized manufacturing system designed for the "blockbuster" drug has driven a slow-paced, inventory heavy operating model that is increasingly regarded as inflexible and unsustainable. Indeed, new markets and the rapidly evolving technology landscape will drive more product variety, shorter product life-cycles, and smaller drug volumes, which will exacerbate an already unsustainable economic model. Future supply chains will be required to enhance affordability and availability for patients and healthcare providers alike despite the increased product complexity. In this more challenging supply scenario, we examine the potential for a more pull driven, near real-time demand-based supply chain, utilizing continuous processing where appropriate as a key element of a more "flow-through" operating model. In this discussion paper on future supply chain models underpinned by developments in the continuous manufacture of pharmaceuticals, we have set out; The significant opportunities to moving to a supply chain flow-through operating model, with substantial opportunities in inventory reduction, lead-time to patient, and radically different product assurance/stability regimes. Scenarios for decentralized production models producing a greater variety of products with enhanced volume flexibility. Production, supply, and value chain footprints that are radically different from today's monolithic and centralized batch manufacturing operations. Clinical trial and drug product development cost savings that support more rapid scale-up and market entry models with early involvement of SC designers within New Product Development. The major supply chain and industrial transformational challenges that need to be addressed. The paper recognizes that although current batch operational

  13. Neuromorphic photonic networks using silicon photonic weight banks.

    Science.gov (United States)

    Tait, Alexander N; de Lima, Thomas Ferreira; Zhou, Ellen; Wu, Allie X; Nahmias, Mitchell A; Shastri, Bhavin J; Prucnal, Paul R

    2017-08-07

    Photonic systems for high-performance information processing have attracted renewed interest. Neuromorphic silicon photonics has the potential to integrate processing functions that vastly exceed the capabilities of electronics. We report first observations of a recurrent silicon photonic neural network, in which connections are configured by microring weight banks. A mathematical isomorphism between the silicon photonic circuit and a continuous neural network model is demonstrated through dynamical bifurcation analysis. Exploiting this isomorphism, a simulated 24-node silicon photonic neural network is programmed using "neural compiler" to solve a differential system emulation task. A 294-fold acceleration against a conventional benchmark is predicted. We also propose and derive power consumption analysis for modulator-class neurons that, as opposed to laser-class neurons, are compatible with silicon photonic platforms. At increased scale, Neuromorphic silicon photonics could access new regimes of ultrafast information processing for radio, control, and scientific computing.

  14. Progress in neuromorphic photonics

    Science.gov (United States)

    Ferreira de Lima, Thomas; Shastri, Bhavin J.; Tait, Alexander N.; Nahmias, Mitchell A.; Prucnal, Paul R.

    2017-03-01

    As society's appetite for information continues to grow, so does our need to process this information with increasing speed and versatility. Many believe that the one-size-fits-all solution of digital electronics is becoming a limiting factor in certain areas such as data links, cognitive radio, and ultrafast control. Analog photonic devices have found relatively simple signal processing niches where electronics can no longer provide sufficient speed and reconfigurability. Recently, the landscape for commercially manufacturable photonic chips has been changing rapidly and now promises to achieve economies of scale previously enjoyed solely by microelectronics. By bridging the mathematical prowess of artificial neural networks to the underlying physics of optoelectronic devices, neuromorphic photonics could breach new domains of information processing demanding significant complexity, low cost, and unmatched speed. In this article, we review the progress in neuromorphic photonics, focusing on photonic integrated devices. The challenges and design rules for optoelectronic instantiation of artificial neurons are presented. The proposed photonic architecture revolves around the processing network node composed of two parts: a nonlinear element and a network interface. We then survey excitable lasers in the recent literature as candidates for the nonlinear node and microring-resonator weight banks as the network interface. Finally, we compare metrics between neuromorphic electronics and neuromorphic photonics and discuss potential applications.

  15. PHOTON09. Proceedings of the international conference on the structure and interactions of the photon including the 18th international workshop on photon-photon collisions and the international workshop on high energy photon linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Behnke, Olaf; Diehl, Markus; Schoerner-Sadenius, Thomas; Steinbrueck, Georg [eds.

    2010-01-15

    The following topics were dealt with: Electroweak and new physics, photon-collider technology, low-energy photon experiments, prompt photons, photon structure, jets and heavy flavours, vacuum polarization and light-by-light scattering, small-x processes, diffraction, total cross sections, exclusive channels and resonances, photons in astroparticle physics. (HSI)

  16. PHOTON09. Proceedings of the international conference on the structure and interactions of the photon including the 18th international workshop on photon-photon collisions and the international workshop on high energy photon linear colliders

    International Nuclear Information System (INIS)

    Behnke, Olaf; Diehl, Markus; Schoerner-Sadenius, Thomas; Steinbrueck, Georg

    2010-01-01

    The following topics were dealt with: Electroweak and new physics, photon-collider technology, low-energy photon experiments, prompt photons, photon structure, jets and heavy flavours, vacuum polarization and light-by-light scattering, small-x processes, diffraction, total cross sections, exclusive channels and resonances, photons in astroparticle physics. (HSI)

  17. Cystic fibrosis transmembrane conductance regulator intracellular processing, trafficking, and opportunities for mutation-specific treatment.

    LENUS (Irish Health Repository)

    Rogan, Mark P

    2012-02-01

    Recent advances in basic science have greatly expanded our understanding of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR), the chloride and bicarbonate channel that is encoded by the gene, which is mutated in patients with CF. We review the structure, function, biosynthetic processing, and intracellular trafficking of CFTR and discuss the five classes of mutations and their impact on the CF phenotype. The therapeutic discussion is focused on the significant progress toward CFTR mutation-specific therapies. We review the results of encouraging clinical trials examining orally administered therapeutics, including agents that promote read-through of class I mutations (premature termination codons); correctors, which overcome the CFTR misfolding that characterizes the common class II mutation F508del; and potentiators, which enhance the function of class III or IV mutated CFTR at the plasma membrane. Long-term outcomes from successful mutation-specific treatments could finally answer the question that has been lingering since and even before the CFTR gene discovery: Will therapies that specifically restore CFTR-mediated chloride secretion slow or arrest the deleterious cascade of events leading to chronic infection, bronchiectasis, and end-stage lung disease?

  18. Organizational Risk and Opportunity Management: Concepts and Processes for NASA's Consideration

    Science.gov (United States)

    Dezfuli, Homayoon; Benjamin, Allan; Everett, Christopher

    2016-01-01

    The focus of this report is on the development of a framework and overall approach that serves the interests of nonprofit and Government organizations like NASA that focus on developing and/or applying new technology (henceforth referred to as organizations like NASA). These interests tend to place emphasis on performing services and achieving scientific and technical gains more than on achieving financial investment goals, which is the province of commercial enterprises. In addition, the objectives of organizations like NASA extend to institutional development and maintenance, financial health, legal and reputational protection, education and partnerships, and mandated milestone achievements. This report discusses the philosophical underpinnings of OROM for organizations like NASA, the integration of OROM with existing management processes, and the nature of the activities that are performed to implement OROM within this context. The proposed framework includes a set of core principles that would be essential to any successful OROM approach, along with some features that are currently under development and are continuing to evolve. The report is intended to foster discussion of OROM at NASA in order to reach a consensus on the optimum approach for the agency.

  19. Photonics: Technology project summary

    Science.gov (United States)

    Depaula, Ramon P.

    1991-01-01

    Photonics involves the use of light (photons) in conjunction with electronics for applications in communications, computing, control, and sensing. Components used in photonic systems include lasers, optical detectors, optical wave guide devices, fiber optics, and traditional electronic devices. The goal of this program is to develop hybrid optoelectronic devices and systems for sensing, information processing, communications, and control. It is hoped that these new devices will yield at least an order of magnitude improvement in performance over existing technology. The objective of the program is to conduct research and development in the following areas: (1) materials and devices; (2) networking and computing; (3) optical processing/advanced pattern recognition; and (4) sensing.

  20. Virtual solar field - An opportunity to optimize transient processes in line-focus CSP power plants

    Science.gov (United States)

    Noureldin, Kareem; Hirsch, Tobias; Pitz-Paal, Robert

    2017-06-01

    Optimizing solar field operation and control is a key factor to improve the competitiveness of line-focus solar thermal power plants. However, the risks of assessing new and innovative control strategies on operational power plants hinder such optimizations and result in applying more conservative control schemes. In this paper, we describe some applications for a whole solar field transient in-house simulation tool developed at the German Aerospace Centre (DLR), the Virtual Solar Field (VSF). The tool offers a virtual platform to simulate real solar fields while coupling the thermal and hydraulic conditions of the field with high computational efficiency. Using the tool, developers and operator can probe their control strategies and assess the potential benefits while avoiding the high risks and costs. In this paper, we study the benefits gained from controlling the loop valves and of using direct normal irradiance maps and forecasts for the field control. Loop valve control is interesting for many solar field operators since it provides a high degree of flexibility to the control of the solar field through regulating the flow rate in each loop. This improves the reaction to transient condition, such as passing clouds and field start-up in the morning. Nevertheless, due to the large number of loops and the sensitivity of the field control to the valve settings, this process needs to be automated and the effect of changing the setting of each valve on the whole field control needs to be taken into account. We used VSF to implement simple control algorithms to control the loop valves and to study the benefits that could be gained from using active loop valve control during transient conditions. Secondly, we study how using short-term highly spatially-resolved DNI forecasts provided by cloud cameras could improve the plant energy yield. Both cases show an improvement in the plant efficiency and outlet temperature stability. This paves the road for further

  1. FY 1998 annual summary report on photon measuring/processing techniques. Development of the techniques for high-efficiency production processes; 1998 nendo foton keisoku kako gijutsu seika hokokusho. Kokoritsu seisan process gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The objectives are set to develop the techniques for energy-efficient laser-aided processing; techniques for high-precision, real-time measurement to improve quality control for production processes and increase their efficiency; and the techniques for generating/controlling photon of high efficiency and quality as the laser beam sources therefor, in order to promote energy saving at and improve efficiency of production processes consuming large quantities of energy, e.g., welding, joining, surface treatment and production of fine particles. The R and D themes are microscopic processing technology: simulation technology for laser welding phenomena; microscopic processing technology: synthesis of technology for quantum dot functional structures; in-situ status measuring technology: fine particle elements and size measurement technology; high-power all-solid-state laser technology: efficient rod type LD-pumping laser modules and pumping chamber of a slab-type laser; tightly-focusing all-solid-state laser technology: improvement of E/O efficiency of laser diode, high-quality nonlinear crystal growth technology and fabrication technology for nonlinear crystal; and comprehensive investigation of photonics engineering: high-efficiency harmonic generation technology. (NEDO)

  2. Flexible photonic-crystal Fano filters based on transferred semiconductor nanomembranes

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Weidong; Yang Hongjun; Qiang Zexuan; Chen Li; Yang Weiquan; Chuwongin, Santhad; Zhao Deyin [Department of Electrical Engineering, NanoFAB Center, University of Texas at Arlington, TX 76019 (United States); Ma Zhenqiang; Qin Guoxuan; Pang Huiqing, E-mail: wzhou@uta.ed, E-mail: mazq@engr.wisc.ed [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, WI 53706 (United States)

    2009-12-07

    Crystalline semiconductor nanomembranes (NMs), which are transferable, stackable, bondable and manufacturable, offer unprecedented opportunities for unique and novel device applications. We report and review here nanophotonic devices based on stacked semiconductor NMs that were built on Si, glass and flexible PET substrates. Photonic-crystal Fano resonance based surface-normal optical filters and broadband reflectors have been demonstrated with unique angle and polarization properties. Such a low temperature NM stacking process can lead to a paradigm shift on silicon photonic integration and inorganic flexible photonics.

  3. Photons, photon jets, and dark photons at 750 GeV and beyond.

    Science.gov (United States)

    Dasgupta, Basudeb; Kopp, Joachim; Schwaller, Pedro

    2016-01-01

    In new physics searches involving photons at the LHC, one challenge is to distinguish scenarios with isolated photons from models leading to "photon jets". For instance, in the context of the 750 GeV diphoton excess, it was pointed out that a true diphoton resonance [Formula: see text] can be mimicked by a process of the form [Formula: see text], where S is a new scalar with a mass of 750 GeV and a is a light pseudoscalar decaying to two collinear photons. Photon jets can be distinguished from isolated photons by exploiting the fact that a large fraction of photons convert to an [Formula: see text] pair inside the inner detector. In this note, we quantify this discrimination power, and we study how the sensitivity of future searches differs for photon jets compared to isolated photons. We also investigate how our results depend on the lifetime of the particle(s) decaying to the photon jet. Finally, we discuss the extension to [Formula: see text], where there are no photons at all but the dark photon [Formula: see text] decays to [Formula: see text] pairs. Our results will be useful in future studies of the putative 750 GeV signal, but also more generally in any new physics search involving hard photons.

  4. Photons, photon jets and dark photons at 750 GeV and beyond

    International Nuclear Information System (INIS)

    Dasgupta, Basudeb; Kopp, Joachim

    2016-03-01

    In new physics searches involving photons at the LHC, one challenge is to distinguish scenarios with isolated photons from models leading to ''photon jets''. For instance, in the context of the 750 GeV diphoton excess, it was pointed out that a true diphoton resonance S → γγ can be mimicked by a process of the form pp → S → aa → 4γ, where S is a new scalar with a mass of 750 GeV and a is a light pseudoscalar decaying to two collinear photons. Photon jets can be distinguished from isolated photons by exploiting the fact that a large fraction of photons convert to an e + e - pair inside the inner detector. In this note, we quantify this discrimination power, and we study how the sensitivity of future searches differs for photon jets compared to isolated photons. We also investigate how our results depend on the lifetime of the particle(s) decaying to the photon jet. Finally, we discuss the extension to S → A'A' → e + e - e + e - , where there are no photons at all but the dark photon A' decays to e + e - pairs. Our results will be useful in future studies of the putative 750 GeV signal, but also more generally in any new physics search involving hard photons.

  5. Contribution of the two-photon annihilation process in the measurement of σ/sub t/ (e+e/sup /minus// → hadrons at PEP)

    International Nuclear Information System (INIS)

    Shen, B.

    1988-01-01

    The possible impact of the 2γ process e/sup /plus//e/sup/minus// → e/sup /plus//e/sup /minus// /plus/ hadrons is evaluated as a source of background for the study of the one photon annihilation process. Two regions of hadron system invariant mass are considered---the resonance region with low invariant mass, and the ''diffractive'' region above 2 GeV hadron invariant mass. In spite of the fact that the 2γ cross-section rises with the energy of the initial e/sup /plus//e/sup /minus// system, it seems clear that measurements of the total energy of the final hadron system will allow the clean separation of the 2γ events from the single photon annihilation reaction

  6. Photonic Hypercrystals

    Directory of Open Access Journals (Sweden)

    Evgenii E. Narimanov

    2014-10-01

    Full Text Available We introduce a new “universality class” of artificial optical media—photonic hypercrystals. These hyperbolic metamaterials, with periodic spatial variation of dielectric permittivity on subwavelength scale, combine the features of optical metamaterials and photonic crystals. In particular, surface waves supported by a hypercrystal possess the properties of both the optical Tamm states in photonic crystals and surface-plasmon polaritons at the metal-dielectric interface.

  7. Single photons on demand

    International Nuclear Information System (INIS)

    Grangier, P.; Abram, I.

    2004-01-01

    Quantum cryptography and information processing are set to benefit from developments in novel light sources that can emit photons one by one. Quantum mechanics has gained a reputation for making counter-intuitive predictions. But we rarely get the chance to witness these effects directly because, being humans, we are simply too big. Take light, for example. The light sources that are familiar to us, such as those used in lighting and imaging or in CD and DVD players, are so huge that they emit billions and billions of photons. But what if there was a light source that emitted just one photon at a time? Over the past few years, new types of light source that are able to emit photons one by one have been emerging from laboratories around the world. Pulses of light composed of a single photon correspond to power flows in the femtowatt range - a million billion times less than that of a table lamp. The driving force behind the development of these single-photon sources is a range of novel applications that take advantage of the quantum nature of light. Quantum states of superposed and entangled photons could lead the way to guaranteed-secure communication, to information processing with unprecedented speed and efficiency, and to new schemes for quantum teleportation. (U.K.)

  8. National Photonics Skills Standard for Technicians.

    Science.gov (United States)

    Center for Occupational Research and Development, Inc., Waco, TX.

    This document defines "photonics" as the generation, manipulation, transport, detection, and use of light information and energy whose quantum unit is the photon. The range of applications of photonics extends from energy generation to detection to communication and information processing. Photonics is at the heart of today's…

  9. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2006-01-01

    Wireless, optical, and electronic networks continue to converge, prompting heavy research into the interface between microwave electronics, ultrafast optics, and photonic technologies. New developments arrive nearly as fast as the photons under investigation, and their commercial impact depends on the ability to stay abreast of new findings, techniques, and technologies. Presenting a broad yet in-depth survey, Microwave Photonics examines the major advances that are affecting new applications in this rapidly expanding field.This book reviews important achievements made in microwave photonics o

  10. Amplified Photon Upconversion by Photonic Shell of Cholesteric Liquid Crystals.

    Science.gov (United States)

    Kang, Ji-Hwan; Kim, Shin-Hyun; Fernandez-Nieves, Alberto; Reichmanis, Elsa

    2017-04-26

    As an effective platform to exploit triplet-triplet-annihilation-based photon upconversion (TTA-UC), microcapsules composed of a fluidic UC core and photonic shell are microfluidically prepared using a triple emulsion as the template. The photonic shell consists of cholesteric liquid crystals (CLCs) with a periodic helical structure, exhibiting a photonic band gap. Combined with planar anchoring at the boundaries, the shell serves as a resonance cavity for TTA-UC emission and enables spectral tuning of the UC under low-power-density excitation. The CLC shell can be stabilized by introducing a polymerizable mesogen in the LC host. Because of the microcapsule spherical symmetry, spontaneous emission of the delayed fluorescence is omnidirectionally amplified at the edge of the stop band. These results demonstrate the range of opportunities provided by TTA-UC systems for the future design of low-threshold photonic devices.

  11. The effective W boson approximation and heavy Higgs production at a photon-photon collider

    International Nuclear Information System (INIS)

    Ma, J.P.

    1995-01-01

    The inclusive production of single Higgs boson at a photon-phonon collider is studied under the effective W boson approximation. The W boson distribution in a photon is determined. The cross section is much larger than this from the photon-photon fusion and this means that a good opportunity of studying heavy Higgs boson can be provided at NLC, where photon beams may be obtained via Compton-backscattering of laser photons off the initial e + e - beams. 8 refs., 1 fig

  12. Fiscal 1999 research report. Research on photonic measurement and processing technology (Development of high- efficiency production process technology); 1999 nendo foton keisoku kako gijutsu seika hokokusho. Kokoritsu seisan process gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This report summarizes the fiscal 1999 research result on R and D of laser processing technology, in-situ measurement technology, and generation and control technology of photon as laser beam source, for energy saving and efficiency improvement of energy-consumptive production processes such as welding, jointing, surface treatment and fine particle fabrication. The research was carried out by a technical center, 9 companies and a university as contract research. The research themes are as follows: (1) Processing technology: simulation technology for laser welding phenomena, synthesis technology for quantum dot functional structures, and fabrication technology for functional composite materials, (2) In-situ measurement technology: fine particle element and size measurement technology, (3) All- solid state laser technology: efficient rod type LD-pumping laser module, pumping chamber of slab type laser, improvement of E/O efficiency of laser diode, high-quality nonlinear crystal growth technology, fabrication technology for nonlinear crystals, and high-efficiency harmonic generation technology. Comprehensive survey was also made on high- efficiency photon generation technologies. (NEDO)

  13. Advanced processing methods to introduce and preserve dipole orientation in organic electro-optic materials for next generation photonic devices

    Science.gov (United States)

    Huang, Su

    ) (PVP) and TOPAS as well as ferroelectric polymer poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE), 65/35 copolymer), which differ largely from the others in dielectric constant, conductivity and surface properties. The only common feature of them is that they all lowered the charge injection and leakage current for 1-2 orders during poling. On every buffer layer we tried, similar trend of stability enhancement is found. These results suggest that the observed temporal stability enhancement is indeed an effect from the abovementioned mechanism. Chapter 4 focuses on the development of an innovative new poling method, which utilizes pyroelectric effect instead of external power sources to overcome the limitations of conventional contact poling and corona poling. With careful theory assisted design, we developed a reliable protocol to efficiently introduce dipole orientation in organic E-O materials by heating and cooling them with detachable pyroelectric crystals. This new method can potentially improve the process adaptability of organic E-O materials in a variety of photonic devices. Large Pockels coefficients (up to 81 pm/V at 1.3 micron) have been successfully achieved in thin films poled using this method. The effective fields in these experiments are estimated to be around 0.5 to 0.9 MV/cm, which agree well with the electrostatics analysis using an idealized model. The same method is directly applied to surface modified hybrid polymer silicon slot waveguide ring-resonator modulators devices. A 25 pm/V tunability of resonance peak wavelength shift has been realized, which was higher than any reported results in similar devices. Chapter 5 discusses about the possible application of the pyroelectric poling in a multi-stack waveguide device architecture. A long-existing challenge to pole E-O polymer based photonic devices is how to effectively drop the poling voltage to the core layer, which is usually sandwiched between two dielectric claddings. In the past

  14. Future Supply Chains Enabled by Continuous Processing-Opportunities Challenges May 20-21 2014 Continuous Manufacturing Symposium.

    Science.gov (United States)

    Srai, Jagjit Singh; Badman, Clive; Krumme, Markus; Futran, Mauricio; Johnston, Craig

    2015-03-01

    This paper examines the opportunities and challenges facing the pharmaceutical industry in moving to a primarily "continuous processing"-based supply chain. The current predominantly "large batch" and centralized manufacturing system designed for the "blockbuster" drug has driven a slow-paced, inventory heavy operating model that is increasingly regarded as inflexible and unsustainable. Indeed, new markets and the rapidly evolving technology landscape will drive more product variety, shorter product life-cycles, and smaller drug volumes, which will exacerbate an already unsustainable economic model. Future supply chains will be required to enhance affordability and availability for patients and healthcare providers alike despite the increased product complexity. In this more challenging supply scenario, we examine the potential for a more pull driven, near real-time demand-based supply chain, utilizing continuous processing where appropriate as a key element of a more "flow-through" operating model. In this discussion paper on future supply chain models underpinned by developments in the continuous manufacture of pharmaceuticals, we have set out; The paper recognizes that although current batch operational performance in pharma is far from optimal and not necessarily an appropriate end-state benchmark for batch technology, the adoption of continuous supply chain operating models underpinned by continuous production processing, as full or hybrid solutions in selected product supply chains, can support industry transformations to deliver right-first-time quality at substantially lower inventory profiles. © 2015 The Authors. Journal of Pharmaceutical Sciences published by Wiley Periodicals, Inc. and the American Pharmacists Association. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  15. Photon-counting image sensors

    CERN Document Server

    Teranishi, Nobukazu; Theuwissen, Albert; Stoppa, David; Charbon, Edoardo

    2017-01-01

    The field of photon-counting image sensors is advancing rapidly with the development of various solid-state image sensor technologies including single photon avalanche detectors (SPADs) and deep-sub-electron read noise CMOS image sensor pixels. This foundational platform technology will enable opportunities for new imaging modalities and instrumentation for science and industry, as well as new consumer applications. Papers discussing various photon-counting image sensor technologies and selected new applications are presented in this all-invited Special Issue.

  16. Ecological opportunity and predator-prey interactions: linking eco-evolutionary processes and diversification in adaptive radiations.

    Science.gov (United States)

    Pontarp, Mikael; Petchey, Owen L

    2018-03-14

    Much of life's diversity has arisen through ecological opportunity and adaptive radiations, but the mechanistic underpinning of such diversification is not fully understood. Competition and predation can affect adaptive radiations, but contrasting theoretical and empirical results show that they can both promote and interrupt diversification. A mechanistic understanding of the link between microevolutionary processes and macroevolutionary patterns is thus needed, especially in trophic communities. Here, we use a trait-based eco-evolutionary model to investigate the mechanisms linking competition, predation and adaptive radiations. By combining available micro-evolutionary theory and simulations of adaptive radiations we show that intraspecific competition is crucial for diversification as it induces disruptive selection, in particular in early phases of radiation. The diversification rate is however decreased in later phases owing to interspecific competition as niche availability, and population sizes are decreased. We provide new insight into how predation tends to have a negative effect on prey diversification through decreased population sizes, decreased disruptive selection and through the exclusion of prey from parts of niche space. The seemingly disparate effects of competition and predation on adaptive radiations, listed in the literature, may thus be acting and interacting in the same adaptive radiation at different relative strength as the radiation progresses. © 2018 The Authors.

  17. One-photon two-electron processes in helium close to the double ionization threshold; Diexcitation electronique de l'helium par un photon au voisinage du seuil de double ionisation

    Energy Technology Data Exchange (ETDEWEB)

    Bouri, C

    2007-04-15

    This work presents a study of the {sup 1}P{sup 0} excited states of He that can be reached by absorption of a single photon carrying an energy close to the double ionization threshold (DIT) (79 eV). Above the DIT, these states are the double continuum states; below, they are the double excited states. These two types of states are tightly coupled to the single continuum states with or without excitation of the residual ion He{sup +}, owing to their degeneracy in energy. In a one-photon process, these states can only be formed owing to the electronic correlations in the system which must be well described to obtain quantitative good results. Our study is a part of the work which aims at a united description of all these doubly excited, ionized-excited, and double continuum states. We use the Hyperspherical R-Matrix with Semiclassical Outgoing Waves (HRM-SOW) method, initially dedicated to double photoionization studies. We extend it to extract information on the single continuum. This extension allows us to compute cross sections of single photoionization with or without excitation up to n 50 for an excess of 100 meV just above the double ionization threshold. A deep insight into this process is given by a partial waves analysis. The results obtained shed light on the key role of angular and radial correlations. The numerous data we obtain on double and single ionization allow us to establish a continuity relation between these two processes. We show that single ionization with an infinite excitation of the residual ion merges into double photoionization when the excess energy is redistributed between the two electrons. It appears that this relation is valid not only for low but also for high photon energies. Since the HRM-SOW can produce the integrated cross section for double photoionization with high accuracy in the low energy domain, we check the Wannier threshold law. The parameters extracted support strongly this threshold law, and are in good agreement with

  18. Fiscal 1997 research report on the R and D project under a consignment from NEDO. Photonics engineering (R and D of photonics measuring/processing technology); 1997 nendo Shin energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku. Photon keisoku kako gijutsu (photon keisoku kako gijutsu no kenkyu kaihatsu) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    Survey was made on the trend of R and D on photonics engineering to clarify the direction of its impact and ripple effect on industrial fields. Reduction of environment burden, improvement of the productivity and reliability of products, and creation of new industries by novel creative R and D are necessary simultaneously. For reconsideration of the previous measurement and machining technologies in a manufacturing industry, use of photon (laser) beams is promising. As photonics engineering, photonics measurement and machining, and elemental and peripheral technologies for generation and control of photon were surveyed. Photonics application technologies for medical care and diagnosis, communication and transmission, entertainment, and chemical fields were also surveyed. In fiscal 1997 as the first year of this project, based on the results obtained in leading researches conducted until fiscal 1996, some technological issues were clarified through the survey on the latest trend of photonics engineering in measurement, machining and generation fields, and its feasibility in the other fields. 265 refs., 91 figs., 10 tabs.

  19. Transmission Planning Process and Opportunities for Utility-Scale Solar Engagement within the Western Electricity Coordinating Council (WECC)

    Energy Technology Data Exchange (ETDEWEB)

    Hein, J.; Hurlbut, D.; Milligan, M.; Coles, L.; Green, B.

    2011-11-01

    This report is a primer for solar developers who wish to engage directly in expediting the regulatory process and removing market barriers related to policy and planning. Market barriers unrelated to technology often limit the expansion of utility-scale solar power, even in areas with exceptional resource potential. Many of these non-technical barriers have to do with policy, regulation, and planning, and hardly ever do they resolve themselves in a timely fashion. In most cases, pre-emptive intervention by interested stakeholders is the easiest way to remove/address such barriers, but it requires knowing how to navigate the institutional waters of the relevant agencies and boards. This report is a primer for solar developers who wish to engage directly in expediting the regulatory process and removing market barriers related to policy and planning. It focuses on the Western Interconnection (WI), primarily because the quality of solar resources in the Southwest makes utility-scale concentrating solar power (CSP) and photovoltaics (PV) economically feasible, and because the relevant institutions have evolved in a way that has opened up opportunities for removing non-technical market barriers. Developers will find in this report a high-level field manual to identify the venues for mitigating and possibly eliminating systemic market obstacles and ensuring that the economic playing field is reasonably level. Project-specific issues such as siting for transmission and generation resources are beyond the scope of this report. Instead, the aim is to examine issues that pervasively affect all utility-scale PV and CSP in the region regardless of where the project may be. While the focus is on the WI, many of the institutions described here also have their counterparts in the Eastern and the Texas interconnections. Specifically, this report suggests a number of critical engagement points relating to generation and transmission planning.

  20. Report on the results of the fiscal 1997 R and D under consignment from NEDO of photon measuring/processing technology (development of high-efficiency production process technology); 1997 nendo Shin energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku photon keisoku kako gijutsu (kokoritsu seisan process gijutsu kaihatsu) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    Development is made of high energy-efficiency laser processing technology and high efficiency/high grade photon generation/control technology as laser light source, for the purpose of energy conservation/efficiency heightening of production processes which require a large amount of energy such as welding, joining, surface treatment, and particle fabrication. As to keyhole dynamics of the molten metal generated on the laser weld, construction of simulational mathematical models was started. Equipment to fabricate semiconductor ultrafine particles which become the core of quantum dot functional structures was designed to fabricate particles. In-situ optical measuring technology was studied of element/size of particles of below 30 nm in size by emission spectroscopy associated with the plasma irradiation. As tightly focusing all-solid-state laser technology, studied was the wavelength conversion method in which harmonics are generated four times as much as the fundamental wave due to high efficient generation of high power UV laser. Also studied were high laser strength, low optical losses, conditions for fostering high homogenity crystals. Technology for high accuracy processing of element surface was established. High efficiency photon generation technology was comprehensively investigated. 140 refs., 276 figs., 46 tabs.

  1. Direct photon experiments

    International Nuclear Information System (INIS)

    Boeggild, H.

    1986-11-01

    The author reviews the experiments on direct photon production in hadronic collisions. After a description of the experimental methods for the study of such processes he presents some results on differential cross sections and the γ/π 0 ratio in π - p, π + p, pp, and anti pp processes as well as in reactions of π - , π + , and p on carbon. (HSI)

  2. Photon generator

    Science.gov (United States)

    Srinivasan-Rao, Triveni

    2002-01-01

    A photon generator includes an electron gun for emitting an electron beam, a laser for emitting a laser beam, and an interaction ring wherein the laser beam repetitively collides with the electron beam for emitting a high energy photon beam therefrom in the exemplary form of x-rays. The interaction ring is a closed loop, sized and configured for circulating the electron beam with a period substantially equal to the period of the laser beam pulses for effecting repetitive collisions.

  3. Application opportunities of systems of control and monitoring for engineering processes fading by JSC 'Instrumental plant 'Tenzor', for utilization and storage of radioactive waste

    International Nuclear Information System (INIS)

    Verbitsky, V.J.; Esaulkov, R.O.; Maslova, M.V.; Kujil, A.S.

    2005-01-01

    Full text: Use of unique automated technological process control systems (ATPCS) on objects of storage of radiation hazardous and nuclear materials is offered. The application opportunity of diagnostic complex consisting of specialized software 'Cruise' and infra-red detection system for control and diagnostics of utilization of nuclear waste products in subcritical thermonuclear equipment is considered

  4. Deduction of the in-medium gluon distribution from photon-gluon fusion processes in peripheral ultrarelativistic heavy-ion collisions

    International Nuclear Information System (INIS)

    Greiner, M.; Hofmann, C.; Schaefer, A.; Soff, G.

    1994-08-01

    The photon-gluon fusion process into a pair of heavy quarks is studied for peripheral Pb+Pb collisions at LHC energies. The double differential cross section with respect to the invariant mass and the rapidity of the produced quark pair at zero rapidity is directly proportional to the gluon distribution in the nuclear medium. Differential cross sections for the b-quark production lie well in the μbarn/GeV regime which will allow the deduction of the gluon distribution at low x. Rapidity cuts for the actual detectors are also considered. (orig.)

  5. Multiple photon resonances

    International Nuclear Information System (INIS)

    Elliott, C.J.; Feldman, B.J.

    1979-02-01

    A detailed theoretical analysis is presented of the interaction of intense near-resonant monochromatic radiation with an N-level anharmonic oscillator. In particular, the phenomenon of multiple photon resonance, the process by which an N-level system resonantly absorbs two or more photons simultaneously, is investigated. Starting from the Schroedinger equation, diagrammatic techniques are developed that allow the resonant process to be analyzed quantitatively, in analogy with well-known two-level coherent phenomena. In addition, multiple photon Stark shifts of the resonances, shifts absent in two-level theory, are obtained from the diagrams. Insights into the nature of multiple photon resonances are gained by comparing the quantum mechanical system with classical coupled pendulums whose equations of motion possess identical eigenvalues and eigenvectors. In certain limiting cases, including that of the resonantly excited N-level harmonic oscillator and that of the equally spaced N-level system with equal matrix elements, analytic results are derived. The influence of population relaxation and phase-disrupting collisions on the multiple photon process are also analyzed, the latter by extension of the diagrammatic technique to the density matrix equations of motion. 11 figures

  6. Valley photonic crystals for control of spin and topology.

    Science.gov (United States)

    Dong, Jian-Wen; Chen, Xiao-Dong; Zhu, Hanyu; Wang, Yuan; Zhang, Xiang

    2017-03-01

    Photonic crystals offer unprecedented opportunity for light manipulation and applications in optical communication and sensing. Exploration of topology in photonic crystals and metamaterials with non-zero gauge field has inspired a number of intriguing optical phenomena such as one-way transport and Weyl points. Recently, a new degree of freedom, valley, has been demonstrated in two-dimensional materials. Here, we propose a concept of valley photonic crystals with electromagnetic duality symmetry but broken inversion symmetry. We observe photonic valley Hall effect originating from valley-dependent spin-split bulk bands, even in topologically trivial photonic crystals. Valley-spin locking behaviour results in selective net spin flow inside bulk valley photonic crystals. We also show the independent control of valley and topology in a single system that has been long pursued in electronic systems, resulting in topologically-protected flat edge states. Valley photonic crystals not only offer a route towards the observation of non-trivial states, but also open the way for device applications in integrated photonics and information processing using spin-dependent transportation.

  7. Valley photonic crystals for control of spin and topology

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Jian-Wen; Chen, Xiao-Dong; Zhu, Hanyu; Wang, Yuan; Zhang, Xiang

    2016-11-28

    Photonic crystals offer unprecedented opportunity for light manipulation and applications in optical communication and sensing1,2,3,4. Exploration of topology in photonic crystals and metamaterials with non-zero gauge field has inspired a number of intriguing optical phenomena such as one-way transport and Weyl points5,6,7,8,9,10. Recently, a new degree of freedom, valley, has been demonstrated in two-dimensional materials11,12,13,14,15. Here, we propose a concept of valley photonic crystals with electromagnetic duality symmetry but broken inversion symmetry. We observe photonic valley Hall effect originating from valley-dependent spin-split bulk bands, even in topologically trivial photonic crystals. Valley–spin locking behaviour results in selective net spin flow inside bulk valley photonic crystals. We also show the independent control of valley and topology in a single system that has been long pursued in electronic systems, resulting in topologically-protected flat edge states. Valley photonic crystals not only offer a route towards the observation of non-trivial states, but also open the way for device applications in integrated photonics and information processing using spin-dependent transportation.

  8. Sub-second photonic processing of solution-deposited single layer and heterojunction metal oxide thin-film transistors using a high-power xenon flash lamp

    KAUST Repository

    Tetzner, Kornelius

    2017-11-01

    We report the fabrication of solution-processed In2O3 and In2O3/ZnO heterojunction thin-film transistors (TFTs) where the precursor materials were converted to their semiconducting state using high power light pulses generated by a xenon flash lamp. In2O3 TFTs prepared on glass substrates exhibited low-voltage operation (≤2 V) and a high electron mobility of ∼6 cm2 V−1 s−1. By replacing the In2O3 layer with a photonically processed In2O3/ZnO heterojunction, we were able to increase the electron mobility to 36 cm2 V−1 s−1, while maintaining the low-voltage operation. Although the level of performance achieved in these devices is comparable to control TFTs fabricated via thermal annealing at 250 °C for 1 h, the photonic treatment approach adopted here is extremely rapid with a processing time of less than 18 s per layer. With the aid of a numerical model we were able to analyse the temperature profile within the metal oxide layer(s) upon flashing revealing a remarkable increase of the layer\\'s surface temperature to ∼1000 °C within ∼1 ms. Despite this, the backside of the glass substrate remains unchanged and close to room temperature. Our results highlight the applicability of the method for the facile manufacturing of high performance metal oxide transistors on inexpensive large-area substrates.

  9. The European project Hippo high-power photonics for satellite laser communications and on-board optical processing

    Science.gov (United States)

    Kehayas, E.; Stampoulidis, L.; Henderson, P.; Robertson, Andrew; Van Dijk, F.; Achouche, M.; Le Kernec, A.; Sotom, M.; Schuberts, F.; Brabant, T.

    2017-11-01

    Photonics is progressively transforming from a highly- focused technology applicable to digital communication networks into a pervasive "enabling" technology with diverse non-telecom applications. However, the centre of mass on the R&D level is still mostly driven by, and invested in, by stakeholders active in the telecoms domain. This is due to the high level of investments necessary that in turn require a large and established market for reaching break-even and generation of revenues. Photonics technology and more specifically, fibre-optic technology is moving into non-telecom business areas with great success in terms of markets captured and penetration rates. One example that cannot be overlooked is the application of fibre-optics to industrial applications, where double-digit growth rates are recorded with fibre lasers and amplifiers constantly gaining momentum. In this example, several years of R&D efforts in creating high-power amplification solutions and fibre-laser sources by the telecom sector, were piggy-backed into industrial applications and laser cutting/welding equipment that is now a strong R&D sector on its own and commercially now displacing some conventional free space laser cutting/welding.

  10. Dirac tensor with heavy photon

    Energy Technology Data Exchange (ETDEWEB)

    Bytev, V.V.; Kuraev, E.A. [Joint Institute of Nuclear Research, Moscow (Russian Federation). Bogoliubov Lab. of Theoretical Physics; Scherbakova, E.S. [Hamburg Univ. (Germany). 1. Inst. fuer Theoretische Physik

    2012-01-15

    For the large-angles hard photon emission by initial leptons in process of high energy annihilation of e{sup +}e{sup -} {yields} to hadrons the Dirac tensor is obtained, taking into account the lowest order radiative corrections. The case of large-angles emission of two hard photons by initial leptons is considered. This result is being completed by the kinematics case of collinear hard photons emission as well as soft virtual and real photons and can be used for construction of Monte-Carlo generators. (orig.)

  11. Photonics for life.

    Science.gov (United States)

    Cubeddu, Rinaldo; Bassi, Andrea; Comelli, Daniela; Cova, Sergio; Farina, Andrea; Ghioni, Massimo; Rech, Ivan; Pifferi, Antonio; Spinelli, Lorenzo; Taroni, Paola; Torricelli, Alessandro; Tosi, Alberto; Valentini, Gianluca; Zappa, Franco

    2011-01-01

    Light is strictly connected with life, and its presence is fundamental for any living environment. Thus, many biological mechanisms are related to light interaction or can be evaluated through processes involving energy exchange with photons. Optics has always been a precious tool to evaluate molecular and cellular mechanisms, but the discovery of lasers opened new pathways of interactions of light with biological matter, pushing an impressive development for both therapeutic and diagnostic applications in biomedicine. The use of light in different fields has become so widespread that the word photonics has been utilized to identify all the applications related to processes where the light is involved. The photonics area covers a wide range of wavelengths spanning from soft X-rays to mid-infrared and includes all devices related to photons as light sources, optical fibers and light guides, detectors, and all the related electronic equipment. The recent use of photons in the field of telecommunications has pushed the technology toward low-cost, compact, and efficient devices, making them available for many other applications, including those related to biology and medicine where these requirements are of particular relevance. Moreover, basic sciences such as physics, chemistry, mathematics, and electronics have recognized the interdisciplinary need of biomedical science and are translating the most advanced researches into these fields. The Politecnico school has pioneered many of them,and this article reviews the state of the art of biomedical research at the Politecnico in the field internationally known as biophotonics.

  12. Advances on integrated microwave photonics

    DEFF Research Database (Denmark)

    Dong, Jianji; Liao, Shasha; Yan, Siqi

    2017-01-01

    Integrated microwave photonics has attracted a lot of attentions and makes significant improvement in last 10 years. We have proposed and demonstrated several schemes about microwave photonics including waveform generation, signal processing and energy-efficient micro-heaters. Our schemes are all...

  13. Hunting the Opportunity

    DEFF Research Database (Denmark)

    Løwe Nielsen, Suna; Rind Christensen, Poul; Lassen, Astrid Heidemann

    2017-01-01

    This paper bring together the two research fields of design and entrepreneurship in order to stimulate new knowledge on opportunity creation. A shared theoretical framework on new opportunity creation that illustrates that design and entrepreneurship can advantageously complement each other in th...... in the opportunity design process. Practical insights into the robustness of the framework are provided by a short illustrative case on electric cars....

  14. Quantum photonics

    CERN Document Server

    Pearsall, Thomas P

    2017-01-01

    This textbook employs a pedagogical approach that facilitates access to the fundamentals of Quantum Photonics. It contains an introductory description of the quantum properties of photons through the second quantization of the electromagnetic field, introducing stimulated and spontaneous emission of photons at the quantum level. Schrödinger’s equation is used to describe the behavior of electrons in a one-dimensional potential. Tunneling through a barrier is used to introduce the concept of non­locality of an electron at the quantum level, which is closely-related to quantum confinement tunneling, resonant tunneling, and the origin of energy bands in both periodic (crystalline) and aperiodic (non-crystalline) materials. Introducing the concepts of reciprocal space, Brillouin zones, and Bloch’s theorem, the determination of electronic band structure using the pseudopotential method is presented, allowing direct computation of the band structures of most group IV, group III-V, and group II-VI semiconducto...

  15. Parton distributions extracted from data on deep-inelastic lepton scattering, prompt photon production and the Drell-Yan process

    International Nuclear Information System (INIS)

    Harriman, P.N.; Martin, A.D.; Stirling, W.J.; Roberts, R.G.

    1990-01-01

    We present a next-to-leading-order QCD structure function analysis of deep-inelastic muon and neutrino scattering data. In particular, we incorporate new F 2 μn /F 2 μp data and take account of a recent re-analysis of SLAC data. The fit is performed simultaneously with next-to-leading-order fits to recent prompt photon and Drell-Yan data. As a result we are able to place tighter constraints on the quark and gluon distributions. Two definitive sets of parton distributions are presented according to which set of muon data is included in the global fit. Comparisons with distributions obtained in earlier analyses are made and the consistency of data sets is investigated. (author)

  16. Two-photon excitation processes to near-ultraviolet states in Ce3+:CaF2

    International Nuclear Information System (INIS)

    Hamilton, D.S.

    1982-11-01

    The two-photon transition to the lowest Ce 3+ 5d state in Ce 3+ :CaF 2 has been investigated. At liquid helium temperatures, a no-phonon resonance line is observed and is accompanied by a vibrational sideband. The peak cross section for this transition is of order 1 x 10 -53 cm 4 s indicating strong parity mixing for the 5d levels. The no-phonon line shows a polarization anisotropy consistent with a tetragonal Ce 3+ site of C 4 /sub V/ symmetry. The phonon side band shows a different anisotropy than the no-phonon line and its polarization characteristics are a function of phonon frequency and temperature

  17. Green photonics

    International Nuclear Information System (INIS)

    Quan, Frederic

    2012-01-01

    Photonics, the broad merger of electronics with the optical sciences, encompasses such a wide swath of technology that its impact is almost universal in our everyday lives. This is a broad overview of some aspects of the industry and their contribution to the ‘green’ or environmental movement. The rationale for energy conservation is briefly discussed and the impact of photonics on our everyday lives and certain industries is described. Some opinions from industry are presented along with market estimates. References are provided to some of the most recent research in these areas. (review article)

  18. Photon correlation in single-photon frequency upconversion.

    Science.gov (United States)

    Gu, Xiaorong; Huang, Kun; Pan, Haifeng; Wu, E; Zeng, Heping

    2012-01-30

    We experimentally investigated the intensity cross-correlation between the upconverted photons and the unconverted photons in the single-photon frequency upconversion process with multi-longitudinal mode pump and signal sources. In theoretical analysis, with this multi-longitudinal mode of both signal and pump sources system, the properties of the signal photons could also be maintained as in the single-mode frequency upconversion system. Experimentally, based on the conversion efficiency of 80.5%, the joint probability of simultaneously detecting at upconverted and unconverted photons showed an anti-correlation as a function of conversion efficiency which indicated the upconverted photons were one-to-one from the signal photons. While due to the coherent state of the signal photons, the intensity cross-correlation function g(2)(0) was shown to be equal to unity at any conversion efficiency, agreeing with the theoretical prediction. This study will benefit the high-speed wavelength-tunable quantum state translation or photonic quantum interface together with the mature frequency tuning or longitudinal mode selection techniques.

  19. Laser ablation of ceramic Al{sub 2}O{sub 3} at 193 nm and 248 nm: The importance of single-photon ionization processes

    Energy Technology Data Exchange (ETDEWEB)

    Pelaez, R. J.; Afonso, C. N. [Laser Processing Group, Instituto de Optica, CSIC, Serrano 121, Madrid 28006 (Spain); Bator, M.; Lippert, T. [General Energy Research Department, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2013-06-14

    The aim of this work is to demonstrate that single-photon photoionization processes make a significant difference in the expansion and temperature of the plasma produced by laser ablation of ceramic Al{sub 2}O{sub 3} in vacuum as well as to show their consequences in the kinetic energy distribution of the species that eventually will impact on the film properties produced by pulsed laser deposition. This work compares results obtained by mass spectrometry and optical spectroscopy on the composition and features of the plasma produced by laser ablation at 193 nm and 248 nm, i.e., photon energies that are, respectively, above and below the ionization potential of Al, and for fluences between threshold for visible plasma and up to Almost-Equal-To 2 times higher. The results show that the ionic composition and excitation of the plasma as well as the ion kinetic energies are much higher at 193 nm than at 248 nm and, in the latter case, the population of excited ions is even negligible. The comparison of Maxwell-Boltzmann temperature, electron temperatures, and densities of the plasmas produced with the two laser wavelengths suggests that the expansion of the plasma produced at 248 nm is dominated by a single population. Instead, the one produced at 193 nm is consistent with the existence of two populations of cold and hot species, the latter associated to Al{sup +} ions that travel at the forefront and produced by single photon ionization as well as Al neutrals and double ionized ions produced by electron-ion impact. The results also show that the most energetic Al neutrals in the plasma produced at the two studied wavelengths are in the ground state.

  20. Laser ablation of ceramic Al2O3 at 193 nm and 248 nm: The importance of single-photon ionization processes

    Science.gov (United States)

    Peláez, R. J.; Afonso, C. N.; Bator, M.; Lippert, T.

    2013-06-01

    The aim of this work is to demonstrate that single-photon photoionization processes make a significant difference in the expansion and temperature of the plasma produced by laser ablation of ceramic Al2O3 in vacuum as well as to show their consequences in the kinetic energy distribution of the species that eventually will impact on the film properties produced by pulsed laser deposition. This work compares results obtained by mass spectrometry and optical spectroscopy on the composition and features of the plasma produced by laser ablation at 193 nm and 248 nm, i.e., photon energies that are, respectively, above and below the ionization potential of Al, and for fluences between threshold for visible plasma and up to ≈2 times higher. The results show that the ionic composition and excitation of the plasma as well as the ion kinetic energies are much higher at 193 nm than at 248 nm and, in the latter case, the population of excited ions is even negligible. The comparison of Maxwell-Boltzmann temperature, electron temperatures, and densities of the plasmas produced with the two laser wavelengths suggests that the expansion of the plasma produced at 248 nm is dominated by a single population. Instead, the one produced at 193 nm is consistent with the existence of two populations of cold and hot species, the latter associated to Al+ ions that travel at the forefront and produced by single photon ionization as well as Al neutrals and double ionized ions produced by electron-ion impact. The results also show that the most energetic Al neutrals in the plasma produced at the two studied wavelengths are in the ground state.

  1. Engaging college physics students with photonics research

    Science.gov (United States)

    Adams, Rhys; Chen, Lawrence R.

    2017-08-01

    As educators and researchers in the field of photonics, we find what we do to be very exciting, and sharing this passion and excitement to our university students is natural to us. Via outreach programs and college research funding, a new college and university collaboration has broadened our student audience: photonics is brought into the college classroom and research opportunities are provided to college students. Photonics-themed active learning activities are conducted in the college Waves and Modern Physics class, helping students forge relationships between course content and modern communications technologies. Presentations on photonics research are prepared and presented by the professor and past college student-researchers. The students are then given a full tour of the photonics university laboratories. Furthermore, funds are set aside to give college students a unique opportunity to assist the college professor with experiments during a paid summer research internship.

  2. Photon Differentials

    DEFF Research Database (Denmark)

    Schjøth, Lars; Frisvad, Jeppe Revall; Erleben, Kenny

    2007-01-01

    illumination features. This is often not desirable as these may lose clarity or vanish altogether. We present an accurate method for reconstruction of indirect illumination with photon mapping. Instead of reconstructing illumination using classic density estimation on finite points, we use the correlation...

  3. Photon Rao

    Indian Academy of Sciences (India)

    Volume 2 Issue 5 May 1997 pp 69-72 Feature Article. Molecule of the Month Molecular–Chameleon: Solvatochromism at its Iridescent Best! Photon Rao · More Details Fulltext PDF. Volume 16 Issue 12 December 2011 pp 1303-1306. Molecule of the Month - Molecular-Chameleon: Solvatochromism at its Iridescent Best!

  4. Silicon photonics fundamentals and devices

    CERN Document Server

    Deen, M Jamal

    2012-01-01

    The creation of affordable high speed optical communications using standard semiconductor manufacturing technology is a principal aim of silicon photonics research. This would involve replacing copper connections with optical fibres or waveguides, and electrons with photons. With applications such as telecommunications and information processing, light detection, spectroscopy, holography and robotics, silicon photonics has the potential to revolutionise electronic-only systems. Providing an overview of the physics, technology and device operation of photonic devices using exclusively silicon and related alloys, the book includes: * Basic Properties of Silicon * Quantum Wells, Wires, Dots and Superlattices * Absorption Processes in Semiconductors * Light Emitters in Silicon * Photodetectors , Photodiodes and Phototransistors * Raman Lasers including Raman Scattering * Guided Lightwaves * Planar Waveguide Devices * Fabrication Techniques and Material Systems Silicon Photonics: Fundamentals and Devices outlines ...

  5. Open innovation at the Abbe School of Photonics

    Science.gov (United States)

    Helgert, Christian; Geiss, Reinhard; Nolte, Stefan; Eilenberger, Falk; Zakoth, David; Mauroner, Oliver; Pertsch, Thomas

    2017-08-01

    The Abbe School of Photonics (ASP) provides and coordinates the optics and photonics education of graduate and doctoral students at the Friedrich Schiller University in Jena, Germany. The internationalized Master's degree program is the key activity in training students in the optical sciences. The program is designed to provide them with the skills necessary to fill challenging positions in industry and academia. Here, an essential factor is ASP's close collaboration with more than 20 German photonics companies. To sustain these partners' future economic development, the availability of highly qualified employees is constantly required. Accordingly, these industrial partners, the European Union, the local state and the federal German government are strongly involved in the sustainable development of ASP's curriculum by both conceptual and financial engagements. The main goal is to promote the students' academic careers and job experience in the photonics industry as well as in academia. To open up the program to students from all over the world, all ASP lectures and courses are taught in English. ASP's qualification strategy is fully research-oriented and based on the principles of academic freedom, competitive research conditions and internationalization at all levels. The education program is complemented by a structured doctoral student support and a prestigious guest professorship program. Recently, ASP and partners have started a project to build an open photonics laboratory in order to foster innovative and co-creative processes. The idea follows well-established open innovation schemes e.g. in electronics. This Photon Garage (German: "Lichtwerkstatt") will bring together professionals and interested laymen from different backgrounds to approach pertinent challenges in photonics. Here, we will share our latest insights into the potentials and opportunities offered by this novel educative approach.

  6. Business opportunities

    Science.gov (United States)

    Los Alamos National Laboratory Search Site submit About Mission Business Newsroom Publications Los : Environmental Documents, Reports LANL Home Calendar Search Contacts Business » Short- and long-term opportunities Business opportunities Setting new standards and developing small business initiatives within NNSA

  7. Time correlation in two-photon decay

    International Nuclear Information System (INIS)

    Hrasko, P.

    1979-11-01

    The relative time distribution of the photons emitted in a second order non-cascade process b→a+2γ is investigated under the assumption that only those photon pairs are detected which were emitted a sufficiently long time after the preparation of the decaying state. An anticorrelation between the photons is found and attributed to the propagation of one of the photons backward in time. (author)

  8. FY 2000 report on the results of the research and development project for the photon-aided instrumentation and processing technologies. Development of high-efficiency production process technologies; 2000 nendo photon keisoku kako gijutsu seika hokokusho. Kokoritsu seisan process gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Described herein are the FY 2000 results of development of the photon-aided instrumentation and processing technologies, aimed at improving efficiency of the production processes which have been massively consuming energy, e.g., those for welding, joining, surface treatment and granulation for producing fine particles. The program for production of the functional composite compounds by the microscopic processing technologies prepares the electrically resistant films and dielectric films by in-situ mixing two types of the ultrafine particles. The program for the in-situ measuring technology is aimed at measuring contents of the constituent components of fine particles, 30nm or less in size, to an accuracy of 10% by the emission spectroscopy, after making them plasmatic. The program for the high-power, all-solid-state laser technology is developing the excited chamber for the high-power, all-solid-state slab type laser, in order to realize the energy-efficient laser-aided processing. The program for the tightly-focusing, all-solid-state laser technology develops the highly uniform crystals by growing the GLBO crystals for producing the high-power ultraviolet laser beams, is developing the techniques for production of the wavelength converting elements, including the GLBO crystal package, and develops the wavelength conversion method by the fourth-harmonic generation with the all-solid-state laser beams as the fundamental wave, realizing the high harmonic power of 23W, for generating the high-power ultraviolet laser beams at a high efficiency. (NEDO)

  9. Photon Collider Physics with Real Photon Beams

    International Nuclear Information System (INIS)

    Gronberg, J; Asztalos, S

    2005-01-01

    Photon-photon interactions have been an important probe into fundamental particle physics. Until recently, the only way to produce photon-photon collisions was parasitically in the collision of charged particles. Recent advances in short-pulse laser technology have made it possible to consider producing high intensity, tightly focused beams of real photons through Compton scattering. A linear e + e - collider could thus be transformed into a photon-photon collider with the addition of high power lasers. In this paper they show that it is possible to make a competitive photon-photon collider experiment using the currently mothballed Stanford Linear Collider. This would produce photon-photon collisions in the GeV energy range which would allow the discovery and study of exotic heavy mesons with spin states of zero and two

  10. Photonic integration and photonics-electronics convergence on silicon platform

    CERN Document Server

    Liu, Jifeng; Baba, Toshihiko; Vivien, Laurent; Xu, Dan-Xia

    2015-01-01

    Silicon photonics technology, which has the DNA of silicon electronics technology, promises to provide a compact photonic integration platform with high integration density, mass-producibility, and excellent cost performance. This technology has been used to develop and to integrate various photonic functions on silicon substrate. Moreover, photonics-electronics convergence based on silicon substrate is now being pursued. Thanks to these features, silicon photonics will have the potential to be a superior technology used in the construction of energy-efficient cost-effective apparatuses for various applications, such as communications, information processing, and sensing. Considering the material characteristics of silicon and difficulties in microfabrication technology, however, silicon by itself is not necessarily an ideal material. For example, silicon is not suitable for light emitting devices because it is an indirect transition material. The resolution and dynamic range of silicon-based interference de...

  11. Effects of Er3+ concentration on UV/blue upconverted luminescence and a three-photon process in the cubic nanocrystalline Y2O3:Er3+

    International Nuclear Information System (INIS)

    Wang Xin; Shan Guiye; Chao Kefu; Zhang Youlin; Liu Ruilin; Feng Liyun; Zeng Qinghui; Sun Yajuan; Liu Yichun; Kong Xianggui

    2006-01-01

    Ultraviolet (UV)/blue upconverted luminescent properties of the cubic Y 2 O 3 :Er 3+ nanocrystals as a function of the erbium concentration were investigated upon 488 nm Ar + laser excitation. The remarkable decrease of upconverted emission intensity and the quenching of the 2 P 3/2 → 4 I 11/2 / 4 I 13/2 transitions were observed in the Y 2 O 3 nanocrystals with high erbium concentration. The emission spectra and the exciting power dependence of upconverted luminescent intensities reveal that the possible upconversion mechanisms are excited-state absorption (ESA) and energy transfer (ET). Moreover, a UV/violet upconverted emission spectrum of nanocrystalline Y 2 O 3 :Er 3+ upon 980 nm light excitation was also observed and a three-photon process made a contribution to this upconverted emission

  12. A practical theoretical formalism for atomic multielectron processes: direct multiple ionization by a single auger decay or by impact of a single electron or photon

    Science.gov (United States)

    Liu, Pengfei; Zeng, Jiaolong; Yuan, Jianmin

    2018-04-01

    Multiple electron processes occur widely in atoms, molecules, clusters, and condensed matters when they are interacting with energetic particles or intense laser fields. Direct multielectron processes (DMEP) are the most complicated among the general multiple electron processes and are the most difficult to describe theoretically. In this work, a unified and accurate theoretical formalism is proposed on the DMEP of atoms including the multiple auger decay and multiple ionization by an impact of a single electron or a single photon based on the atomic collision theory described by a correlated many-body Green's function. Such a practical treatment is made possible by taking consideration of the different coherence features of the atoms (matter waves) in the initial and final states. We first explain how the coherence characteristics of the ejected continuum electrons is largely destructed, by taking the electron impact direct double ionization process as an example. The direct double ionization process is completely different from the single ionization where the complete interference can be maintained. The detailed expressions are obtained for the energy correlations among the continuum electrons and energy resolved differential and integral cross sections according to the separation of knock-out (KO) and shake-off (SO) mechanisms for the electron impact direct double ionization, direct double and triple auger decay, and double and triple photoionization (TPI) processes. Extension to higher order DMEP than triple ionization is straight forward by adding contributions of the following KO and SO processes. The approach is applied to investigate the electron impact double ionization processes of C+, N+, and O+, the direct double and triple auger decay of the K-shell excited states of C+ 1s2{s}22{p}2{}2D and {}2P, and the double and TPI of lithium. Comparisons with the experimental and other theoretical investigations wherever available in the literature show that our

  13. Fiscal 1997 report under consignment from NEDO on photon measuring/processing technology (development of power generation facility use high-function maintenance technology); 1997 nendo Shin energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku photon keisoku kako gijutsu (hatsuden shisetsuyo kokino maintenance gijutsu kaihatsu) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    A research/development was conducted on technologies of photon applied measuring/photon applied processing/photon generation which are usable for heightening of reliability and maintenance efficiency of power generation facilities. In fiscal 1997, high melting-point metal particles were manufactured by high energy density laser for formation of high temperature and stabilized fine functional circuit. Further, a wavelength changeable ultra red laser light source was studied which can make in-situ measurement of gas concentration and components. A study was also made to examine the surface composition by measuring fluorescent X-rays emitted by radiating high intensity laser beam on the surface of material. A rod type and a slab type as a high-output complete-solidified laser are under development. There is also a development aiming at high speed/high quality photon processing such as high speed/high precision welding/cutting and laser joining. Besides, a study is being made of high energy pulse/high quality beam complete-solidified laser. The paper made a comprehensive survey of the trend of the photon measuring/monitoring technology, and made a systematical arrangement of the developmental subjects extracted. 142 refs., 357 figs., 62 tabs.

  14. SWOT analysis of Banff: strengths, weaknesses, opportunities and threats of the international Banff consensus process and classification system for renal allograft pathology.

    Science.gov (United States)

    Mengel, M; Sis, B; Halloran, P F

    2007-10-01

    The Banff process defined the diagnostic histologic lesions for renal allograft rejection and created a standardized classification system where none had existed. By correcting this deficit the process had universal impact on clinical practice and clinical and basic research. All trials of new drugs since the early 1990s benefited, because the Banff classification of lesions permitted the end point of biopsy-proven rejection. The Banff process has strengths, weaknesses, opportunities and threats (SWOT). The strength is its self-organizing group structure to create consensus. Consensus does not mean correctness: defining consensus is essential if a widely held view is to be proved wrong. The weaknesses of the Banff process are the absence of an independent external standard to test the classification; and its almost exclusive reliance on histopathology, which has inherent limitations in intra- and interobserver reproducibility, particularly at the interface between borderline and rejection, is exactly where clinicians demand precision. The opportunity lies in the new technology such as transcriptomics, which can form an external standard and can be incorporated into a new classification combining the elegance of histopathology and the objectivity of transcriptomics. The threat is the degree to which the renal transplant community will participate in and support this process.

  15. Microwave Photonic Architecture for Direction Finding of LPI Emitters: Post-Processing for Angle of Arrival Estimation

    Science.gov (United States)

    2016-09-01

    APPENDIX. MATLAB CODE FOR SYSTEM SIMULATION .................................65  LIST OF REFERENCES...it easily detectable. The transmission of LPI signals with sophisticated modulation and high processing gain enable a good detection range and low...and data collection process . The software simulation of the system, which supports the hypothesis that the physical system is capable of detecting

  16. Monoclonal Antibodies Production Platforms: An Opportunity Study of a Non-Protein-A Chromatographic Platform Based on Process Economics.

    Science.gov (United States)

    Grilo, António L; Mateus, Marília; Aires-Barros, Maria R; Azevedo, Ana M

    2017-12-01

    Monoclonal antibodies currently dominate the biopharmaceutical market with growing sales having reached 80 billion USD in 2016. As most top-selling mAbs are approaching the end of their patent life, biopharmaceutical companies compete fiercely in the biosimilars market. These two factors present a strong motivation for alternative process strategies and process optimization. In this work a novel purification strategy for monoclonal antibodies comprising phenylboronic acid multimodal chromatography for capture followed by polishing by ion-exchange monolithic chromatography and packed bed hydrophobic interaction chromatography is presented and compared to the traditional protein-A-based process. Although the capital investment is similar for both processes, the operation cost is 20% lower for the novel strategy. This study shows that the new process is worthwhile investing in and could present a viable alternative to the platform process used by most industrial players. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Photon-hadron and photon-photon collisions in CMS (including data from p-p, p-A and A-A collisions)

    CERN Document Server

    Rebello Teles, Patricia

    2015-01-01

    Photon-nucleus and photon-photon collisions are abundantly produced at the LHC. The LHC provides a unique opportunity to study high-energy photon-photon interactions, thanks to its high energy and large integrated luminosity. In this talk two CMS analyses concerning photon-hadron and photon-photon collisions are going to be presented. The first deals with the measurement of the coherent $J/\\Psi$ photoproduction cross section in ultra-peripheral PbPb collisions at $\\sqrt{s_{NN}}$ = 2.76 TeV in conjunction with forward neutrons. The second one shows the evidence of the exclusive $\\gamma \\gamma \\to W^{+}W^{-}$ production and improvement on constraints for the anomalous gauge quartic coupling $\\gamma \\gamma WW$ parameters.

  18. Photon collider at TESLA

    International Nuclear Information System (INIS)

    Telnov, Valery

    2001-01-01

    High energy photon colliders (γγ, γe) based on backward Compton scattering of laser light is a very natural addition to e + e - linear colliders. In this report, we consider this option for the TESLA project. Recent study has shown that the horizontal emittance in the TESLA damping ring can be further decreased by a factor of four. In this case, the γγ luminosity in the high energy part of spectrum can reach about (1/3)L e + e - . Typical cross-sections of interesting processes in γγ collisions are higher than those in e + e - collisions by about one order of magnitude, so the number of events in γγ collisions will be more than that in e + e - collisions. Photon colliders can, certainly, give additional information and they are the best for the study of many phenomena. The main question is now the technical feasibility. The key new element in photon colliders is a very powerful laser system. An external optical cavity is a promising approach for the TESLA project. A free electron laser is another option. However, a more straightforward solution is ''an optical storage ring (optical trap)'' with a diode pumped solid state laser injector which is today technically feasible. This paper briefly reviews the status of a photon collider based on the linear collider TESLA, its possible parameters and existing problems

  19. Photon absorptiometry

    International Nuclear Information System (INIS)

    Valkema, R.; Blokland, J.A.K.; Papapoulos, S.E.; Bijvoet, O.L.M.; Pauwels, E.K.J.

    1989-01-01

    Osteoporosis is a significant health problem in the western world, with important medical, social and economical consequences. Prevention and treatment require reliable methods for in vivo monitoring of the bone mineral content (BMC) and its change in time. This paper presents an overview of currently used radiological methods, based on photon absorptiometry, and their clinical applications. With recent methods based on dual energy X-ray absorptiometry accurate and precise measurements of axial BMC can be obtained. Whether this improvements allows reliable detection of small changes in BMC remains to be investigated. (Author). 95 refs.; 1 tab

  20. Examining Quality Management Audits in Nuclear Medicine Practice as a lifelong learning process: opportunities and challenges to the nuclear medicine professional and beyond.

    Science.gov (United States)

    Pascual, Thomas N B

    2016-08-01

    This essay will explore the critical issues and challenges surrounding lifelong learning for professionals, initially exploring within the profession and organizational context of nuclear medicine practice. It will critically examine how the peer-review process called Quality Management Audits in Nuclear Medicine Practice (QUANUM) of the International Atomic Energy Agency (IAEA) can be considered a lifelong learning opportunity to instill a culture of quality to improve patient care and elevate the status of the nuclear medicine profession and practice within the demands of social changes, policy, and globalization. This will be explored initially by providing contextual background to the identity of the IAEA as an organization responsible for nuclear medicine professionals, followed by the benefits that QUANUM can offer. Further key debates surrounding lifelong learning, such as compulsification of lifelong learning and impact on professional change, will then be weaved through the discussion using theoretical grounding through a qualitative review of the literature. Keeping in mind that there is very limited literature focusing on the implications of QUANUM as a lifelong learning process for nuclear medicine professionals, this essay uses select narratives and observations of QUANUM as a lifelong learning process from an auditor's perspective and will further provide a comparative perspective of QUANUM on the basis of other lifelong learning opportunities such as continuing professional development activities and observe parallelisms on its benefits and challenges that it will offer to other professionals in other medical speciality fields and in the teaching profession.

  1. The Methodical Bases of Assessment of Innovation Processes in the Sphere of Power Generation with Use of Opportunities of Cognitive Modeling

    Directory of Open Access Journals (Sweden)

    Vikhlyaeva Nataliya V.

    2017-10-01

    Full Text Available The article presents the methodical bases of assessing the innovation processes of power generating companies with use of opportunities of cognitive modeling. It is specified that the method of cognitive modeling allows to remove contradictions concerning the interrelationship of the factors determining the innovation processes of the energy generating companies that usually arise when the results of research on the elements of the innovation system are being coordinated. Based on the arguments and practical examples, provided in the article, it was concluded that application of the method of cognitive modeling in the process of assessing the innovative capabilities of energy-generating companies is a sufficiently flexible and effective tool for supporting decision-making on strategic directions of their development.

  2. Essentials of photonics

    CERN Document Server

    Rogers, Alan; Baets, Roel

    2008-01-01

    Photons and ElectronsHistorical SketchThe Wave Nature of LightPolarizationThe Electromagnetic SpectrumEmission and Absorption ProcessesPhoton Statistics The Behaviour of Electrons LasersSummaryWave Properties of LightThe Electromagnetic SpectrumWave RepresentationElectromagnetic WavesReflection and RefractionTotal Internal ReflectionInterference of LightLight WaveguidingInterferometersDiffractionGaussian Beams and Stable Optical ResonatorsPolarization OpticsThe Polarization EllipseCrystal OpticsRetarding WaveplatesA Variable Waveplate: The Soleil-Babinet Compensator Polarizing PrismsLinear BirefringenceCircular BirefringenceElliptical BirefringencePractical Polarization EffectsPolarization AnalysisThe Form of the Jones MatricesLight and Matter Emission, Propagation, and Absorption ProcessesClassical Theory of Light Propagation in Uniform Dielectric Media Optical Dispersion Emission and Absorption of LightOptical Coherence and CorrelationIntroductionMeasure of Coherence Wiener-Khinchin TheoremDual-Beam Interfe...

  3. Photonic Microresonator Research and Applications

    CERN Document Server

    Chremmos, Ioannis; Uzunoglu, Nikolaos

    2010-01-01

    Photonic Microresonator Research and Applications explores advances in the fabrication process that enable nanometer waveguide separations. The technology surrounding the design and fabrication of optical microresonators has matured to a point where there is a need for commercialization. Consequently, there is a need for device research involving more advanced architectures and more esoteric operating princples. This volume discusses these issues, while also: Showing a reader how to design and fabricate microresonators Discussing microresonators in photonic crystals, microsphere circuits, and sensors, and provides application oriented examples Covering the latest in microresonator research with contributions from the leading researchers Photonic Microresonator Research and Applications would appeal to researchers and academics working in the optical sciences.

  4. Evaluating Opportunities for Improved Processes and Flow Rates in Royal Saudi Air Force F-15 Reparable Items Supply Chain

    Science.gov (United States)

    2015-09-15

    of manpower to the focal company’s development and product commercialization process, availability of products in times of shortage , and/or...their employees to help improvements teams, by notifying them about any shortage or problems in the process, rather than blaming employees for...cargo services are used in air-shipping those parts to the United States. Then, parts are consolidated by the FF in the Wilmington warehouse , and

  5. Separation of quark and gluon gets in the direct photon production processes at the LHC using the neural network approach

    International Nuclear Information System (INIS)

    Bandurin, D.V.; Skachkov, N.B.

    2001-01-01

    A neural network technique is used to discriminate between quark and gluon jets produced in the qg→q+γ and qq bar → g+γ processes at the LHC. Considering the network as a trigger and using the PYTHIA event generator and the full event fast simulation CMSJET package for the CMS detector we obtain signal-to-background ratios

  6. Formosa Plastics Corporation: Plant-Wide Assessment of Texas Plant Identifies Opportunities for Improving Process Efficiency and Reducing Energy Costs

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-01-01

    At Formosa Plastics Corporation's plant in Point Comfort, Texas, a plant-wide assessment team analyzed process energy requirements, reviewed new technologies for applicability, and found ways to improve the plant's energy efficiency. The assessment team identified the energy requirements of each process and compared actual energy consumption with theoretical process requirements. The team estimated that total annual energy savings would be about 115,000 MBtu for natural gas and nearly 14 million kWh for electricity if the plant makes several improvements, which include upgrading the gas compressor impeller, improving the vent blower system, and recovering steam condensate for reuse. Total annual cost savings could be $1.5 million. The U.S. Department of Energy's Industrial Technologies Program cosponsored this assessment.

  7. Ground facility for information reception, processing, dissemination and scientific instruments management setup in the CORONAS-PHOTON space project

    Science.gov (United States)

    Buslov, A. S.; Kotov, Yu. D.; Yurov, V. N.; Bessonov, M. V.; Kalmykov, P. A.; Oreshnikov, E. M.; Alimov, A. M.; Tumanov, A. V.; Zhuchkova, E. A.

    2011-06-01

    This paper deals with the organizational structure of ground-based receiving, processing, and dissemination of scientific information created by the Astrophysics Institute of the Scientific Research Nuclear University, Moscow Engineering Physics Institute. Hardware structure and software features are described. The principles are given for forming sets of control commands for scientific equipment (SE) devices, and statistics data are presented on the operation of facility during flight tests of the spacecraft (SC) in the course of one year.

  8. Coupling the photon kinetics of soft photons with high energy photons

    Science.gov (United States)

    Silva, L. O.; Bingham, R.

    2017-10-01

    The description of electromagnetic fields based on the generalized photon kinetic theory, which takes advantage of the Wigner-Moyal description for the corresponding classical field theory, is capable of capturing collective plasma dynamics in the relativistic regime driven by broadband incoherent or partially coherent sources. We explore the possibility to extend this description to include the dynamics of hard photons in the plasma, whose interaction is dominated by single scattering processes. Examples of the modification of classical plasma instabilities due to the presence of hard photons is discussed. Work supported by the European Research Council (ERC-AdG-2015 InPairs Grant No. 695088).

  9. Quasimetallic silicon micromachined photonic crystals

    International Nuclear Information System (INIS)

    Temelkuran, B.; Bayindir, Mehmet; Ozbay, E.; Kavanaugh, J. P.; Sigalas, M. M.; Tuttle, G.

    2001-01-01

    We report on fabrication of a layer-by-layer photonic crystal using highly doped silicon wafers processed by semiconductor micromachining techniques. The crystals, built using (100) silicon wafers, resulted in an upper stop band edge at 100 GHz. The transmission and defect characteristics of these structures were found to be analogous to metallic photonic crystals. We also investigated the effect of doping concentration on the defect characteristics. The experimental results agree well with predictions of the transfer matrix method simulations

  10. Dynamic Processes in Biology, Chemistry, and Materials Science: Opportunities for UltraFast Transmission Electron Microscopy - Workshop Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Kabius, Bernd C.; Browning, Nigel D.; Thevuthasan, Suntharampillai; Diehl, Barbara L.; Stach, Eric A.

    2012-07-25

    This report summarizes a 2011 workshop that addressed the potential role of rapid, time-resolved electron microscopy measurements in accelerating the solution of important scientific and technical problems. A series of U.S. Department of Energy (DOE) and National Academy of Science workshops have highlighted the critical role advanced research tools play in addressing scientific challenges relevant to biology, sustainable energy, and technologies that will fuel economic development without degrading our environment. Among the specific capability needs for advancing science and technology are tools that extract more detailed information in realistic environments (in situ or operando) at extreme conditions (pressure and temperature) and as a function of time (dynamic and time-dependent). One of the DOE workshops, Future Science Needs and Opportunities for Electron Scattering: Next Generation Instrumentation and Beyond, specifically addressed the importance of electron-based characterization methods for a wide range of energy-relevant Grand Scientific Challenges. Boosted by the electron optical advancement in the last decade, a diversity of in situ capabilities already is available in many laboratories. The obvious remaining major capability gap in electron microscopy is in the ability to make these direct in situ observations over a broad spectrum of fast (µs) to ultrafast (picosecond [ps] and faster) temporal regimes. In an effort to address current capability gaps, EMSL, the Environmental Molecular Sciences Laboratory, organized an Ultrafast Electron Microscopy Workshop, held June 14-15, 2011, with the primary goal to identify the scientific needs that could be met by creating a facility capable of a strongly improved time resolution with integrated in situ capabilities. The workshop brought together more than 40 leading scientists involved in applying and/or advancing electron microscopy to address important scientific problems of relevance to DOE’s research

  11. Analysing the Opportunities and Challenges to Use of Information and Communication Technology Tools in Teaching-Learning Process

    Science.gov (United States)

    Dastjerdi, Negin Barat

    2016-01-01

    The research aims at the evaluation of ICT use in teaching-learning process to the students of Isfahan elementary schools. The method of this research is descriptive-surveying. The statistical population of the study was all teachers of Isfahan elementary schools. The sample size was determined 350 persons that selected through cluster sampling…

  12. FY 1998 annual summary report on photon measuring/processing techniques. Development of highly functional maintenance techniques for power generating facilities; 1998 nendo foton keisoku kako gijutsu. Hatsuden shisetsuyo kokino maintenance gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The objectives are set to develop the techniques for non-destructive measurement of conditions of facility portions, especially those exposed to severe environments, e.g., elevated temperature and pressure, over a wide range; the techniques for measurement of leakage of, e.g., gases, at high sensitivity; the techniques of laser-aided welding and surface-modification treatment for the members exposed to severe conditions; and the techniques for generating photon beams of high quality and energy density as the tools therefor, in order to improve reliability and maintenance efficiency of power generating facilities. The R and D themes are microscopic processing technology: fabrication technology for functional micro-composite circuits; in-situ status measuring technology: gas concentration/component measurement technology, and photon wavefront compensation device technology; non-destructive composition measuring technology: high-sensitivity detection technology using short-wavelength photons; high-power all-solid-state laser technology: rod-type laser and slab-type laser; tightly-focusing all-solid-state laser technology: high-energy pulse, high-quality laser; and comprehensive investigation of photonics engineering: investigation for photon-applied measurement technologies. (NEDO)

  13. ITMO Photonics: center of excellence

    Science.gov (United States)

    Voznesenskaya, Anna; Bougrov, Vladislav; Kozlov, Sergey; Vasilev, Vladimir

    2016-09-01

    ITMO University, the leading Russian center in photonics research and education, has the mission to train highlyqualified competitive professionals able to act in conditions of fast-changing world. This paradigm is implemented through creation of a strategic academic unit ITMO Photonics, the center of excellence concentrating organizational, scientific, educational, financial, laboratory and human resources. This Center has the following features: dissemination of breakthrough scientific results in photonics such as advanced photonic materials, ultrafast optical and quantum information, laser physics, engineering and technologies, into undergraduate and graduate educational programs through including special modules into the curricula and considerable student's research and internships; transformation of the educational process in accordance with the best international educational practices, presence in the global education market in the form of joint educational programs with leading universities, i.e. those being included in the network programs of international scientific cooperation, and international accreditation of educational programs; development of mechanisms for the commercialization of innovative products - results of scientific research; securing financial sustainability of research in the field of photonics of informationcommunication systems via funding increase and the diversification of funding sources. Along with focusing on the research promotion, the Center is involved in science popularization through such projects as career guidance for high school students; interaction between student's chapters of international optical societies; invited lectures of World-famous experts in photonics; short educational programs in optics, photonics and light engineering for international students; contests, Olympics and grants for talented young researchers; social events; interactive demonstrations.

  14. Measure Guideline: Wall Air Sealing and Insulation Methods in Existing Homes; An Overview of Opportunity and Process

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, S.; Stephenson, R.

    2012-09-01

    This guide provides renovators and retrofit contractors an overview of considerations when including wall air sealing and insulation in an energy retrofit project. It also outlines the potential project risks, various materials for insulating, possible field inspections needed, installation procedures, as well as the benefits and drawbacks. The purpose of this document is to provide the outline of the overview and process of insulating and air sealing walls so that home retrofit professionals can identify approaches to air sealing and insulation measures.

  15. Physics at high energy photon photon colliders

    International Nuclear Information System (INIS)

    Chanowitz, M.S.

    1994-06-01

    I review the physic prospects for high energy photon photon colliders, emphasizing results presented at the LBL Gamma Gamma Collider Workshop. Advantages and difficulties are reported for studies of QCD, the electroweak gauge sector, supersymmetry, and electroweak symmetry breaking

  16. Resonance formation in photon-photon collisions

    International Nuclear Information System (INIS)

    Gidal, G.

    1988-08-01

    Recent experimental progress on resonance formation in photon-photon collisions is reviewed with particular emphasis on the pseudoscalar and tensor nonents and on the γγ* production of spin-one resonances. 37 refs., 17 figs., 5 tabs

  17. FDTD simulation for plasma photonic crystals

    International Nuclear Information System (INIS)

    Liu Shaobin; Zhu Chuanxi; Yuan Naichang

    2005-01-01

    Plasma photonic crystals are artificially periodic structures, which are composed of plasmas and dielectric structures (or vacuum). In this paper, the piecewise linear current density recursive convolution (PLCDRC) finite-difference time-domain (FDTD) method is applied to study the plasma photonic crystals and those containing defects. In time-domain, the electromagnetic (EM) propagation process and reflection/transmission electric field of Gauss pulses passing through the plasma photonic crystals are investigated. In frequency-domain, the reflection and transmission coefficients of the pulses through the two kinds of crystals are computed. The results illustrate that the plasma photonic crystals mostly reflect for the EM wave of frequencies less than the plasma frequency, and mostly transmit for EM wave of frequencies higher than the plasma frequency. In high frequency domain, the plasma photonic crystals have photonic band gaps, which is analogous to the conventional photonic crystals. (authors)

  18. Optimization of the production process of hybrid and multivalent formulation Bombesin/RGD for the opportune detection of breast cancer

    International Nuclear Information System (INIS)

    Robles M, M.

    2013-01-01

    The radiopharmaceuticals of third generation are used in nuclear medicine to obtain images of specific molecular targets, and they are unique in their capacity to detect in vivo specific biochemical sites as receptors that are over-expressed in diverse illness. In cancer cells several types of receptors are over-expressed, as the integrin s α(v)β(3) and α(v)β(5) that specifically recognize the sequence RGD (Arginine-Glycin-Ac. Aspartic) and gastrin-releasing peptide that recognizes specifically to the peptide Lys 3 -Bombesin. The integrin s α(v)β(3) and α(v)β(5) are involved in the tumor angio genesis processes and the gastrin-releasing peptide is over-expressed in breast and prostate cancer. The molecular recognition of the specific receptors is the basis to be utilized as targets of the radiopharmaceuticals 99m Tc-HYNIC-Bombesin and 99m Tc-HYNIC-RGD. In this work was developed a lyophilized pharmaceutical formulation effective, stable and safe for the simultaneous obtaining of the radiopharmaceuticals 99m Tc-HYNIC-Bombesin ( 99m Tc-EDDA/HYNIC-Lys 3 -Bombesin) and 99m Tc-HYNIC-RGD ( 99m Tc EDDA/HYNIC-E-[c(RGDfK)] 2 ). Later on the production process of the product HYNIC-Bombesin/RGD-Sn was optimized using a factorial design and the formulation was transferred to the production plant of radiopharmaceuticals of the Instituto Nacional de Investigaciones Nucleares (ININ). The optimized formulation is described in the following chart: HYNIC-[Lys 3 ]-Bombesin - 12.5 μg; HYNIC-E-c[RGDfK] 2 - 12.5 μg; Stannous chloride (SnCl 2 ) - 20 μg; Ethylenediamine diacetic acid (EDDA) - 10 mg; N-tris(hydroxymethyl)methyl glycin (Tricine) - 20 mg; Mannitol - 50 mg. The production process was validated and were carried out the stability studies under refrigeration conditions. (Author)

  19. Energy Efficiency Improvement and Cost Saving Opportunities for the Dairy Processing Industry: An ENERGY STAR? Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Brush, Adrian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Masanet, Eric [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Worrell, Ernst [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2011-10-01

    The U.S. dairy processing industry—defined in this Energy Guide as facilities engaged in the conversion of raw milk to consumable dairy products—consumes around $1.5 billion worth of purchased fuels and electricity per year. Energy efficiency improvement is an important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There are a variety of opportunities available at individual plants in the U.S. dairy processing industry to reduce energy consumption and greenhouse gas emissions in a cost-effective manner. This Energy Guide discusses energy efficiency practices and energy-efficient technologies that can be implemented at the component, process, facility, and organizational levels. A discussion of the trends, structure, and energy consumption characteristics of the U.S. dairy processing industry is provided along with a description of the major process technologies used within the industry. Next, a wide variety of energy efficiency measures applicable to dairy processing plants are described. Many measure descriptions include expected savings in energy and energy-related costs, based on case study data from real-world applications in dairy processing facilities and related industries worldwide. Typical measure payback periods and references to further information in the technical literature are also provided, when available. Given the importance of water in dairy processing, a summary of basic, proven measures for improving water efficiency are also provided. The information in this Energy Guide is intended to help energy and plant managers in the U.S. dairy processing industry reduce energy and water consumption in a cost-effective manner while maintaining the quality of products manufactured. Further research on the economics of all measures—as well as on their applicability to different production practices—is needed to assess their cost effectiveness at individual plants.

  20. Energy Efficiency Improvement and Cost Saving Opportunities for the Fruit and Vegetable Processing Industry. An ENERGY STAR Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Masanet, Eric; Masanet, Eric; Worrell, Ernst; Graus, Wina; Galitsky, Christina

    2008-01-01

    The U.S. fruit and vegetable processing industry--defined in this Energy Guide as facilities engaged in the canning, freezing, and drying or dehydrating of fruits and vegetables--consumes over $800 million worth of purchased fuels and electricity per year. Energy efficiency improvement isan important way to reduce these costs and to increase predictable earnings, especially in times of high energy price volatility. There are a variety of opportunities available at individual plants in the U.S. fruit and vegetable processing industry to reduce energy consumption in a cost-effective manner. This Energy Guide discusses energy efficiency practices and energy-efficient technologies that can be implemented at the component, process, facility, and organizational levels. A discussion of the trends, structure, and energy consumption characteristics of the U.S. fruit and vegetable processing industry is provided along with a description of the major process technologies used within the industry. Next, a wide variety of energy efficiency measures applicable to fruit and vegetable processing plants are described. Many measure descriptions include expected savings in energy and energy-related costs, based on case study data from real-world applications in fruit and vegetable processing facilities and related industries worldwide. Typical measure payback periods and references to further information in the technical literature are also provided, when available. Given the importance of water in fruit and vegetable processing, a summary of basic, proven measures for improving plant-level water efficiency are also provided. The information in this Energy Guide is intended to help energy and plant managers in the U.S. fruit and vegetable processing industry reduce energy and water consumption in a cost-effective manner while maintaining the quality of products manufactured. Further research on the economics of all measures--as well as on their applicability to different production

  1. Opportunities in biotechnology.

    Science.gov (United States)

    Gartland, Kevan M A; Gartland, Jill S

    2018-06-08

    Strategies for biotechnology must take account of opportunities for research, innovation and business growth. At a regional level, public-private collaborations provide potential for such growth and the creation of centres of excellence. By considering recent progress in areas such as genomics, healthcare diagnostics, synthetic biology, gene editing and bio-digital technologies, opportunities for smart, strategic and specialised investment are discussed. These opportunities often involve convergent or disruptive technologies, combining for example elements of pharma-science, molecular biology, bioinformatics and novel device development to enhance biotechnology and the life sciences. Analytical applications use novel devices in mobile health, predictive diagnostics and stratified medicine. Synthetic biology provides opportunities for new product development and increased efficiency for existing processes. Successful centres of excellence should promote public-private business partnerships, clustering and global collaborations based on excellence, smart strategies and innovation if they are to remain sustainable in the longer term. Copyright © 2018. Published by Elsevier B.V.

  2. Modelling of photonic crystal fibres

    DEFF Research Database (Denmark)

    Knudsen, Erik

    2003-01-01

    , as well as a honeycomb bandgap fibre and the first analysis of semi-periodic layered air-hole fibres. Using the modelling framework established as a basis, we provide an analysis of microbend loss, by regarding displacement of a fibre core as a stationary stochastic process, inducing mismatch between......In the presenta ph.d. work a theoretical study of aspects of modelling photonic crystal fibres was carried out. Photonic crystal fibres form a class of optical waveguides where guidance is no longer provided by a difference in refractive index between core and cladding. Instead, guidance...... is provided by an arrangement of air-holes running along the length of the fibre. Depending on the geometry of the fibre, the guiding mechanism may be either arising from the formation of a photonic bandgap in the cladding structure (photonic bandgap fibre), or by an effect resembling total internal...

  3. Tunable Multiband Microwave Photonic Filters

    Directory of Open Access Journals (Sweden)

    Mable P. Fok

    2017-11-01

    Full Text Available The increasing demand for multifunctional devices, the use of cognitive wireless technology to solve the frequency resource shortage problem, as well as the capabilities and operational flexibility necessary to meet ever-changing environment result in an urgent need of multiband wireless communications. Spectral filter is an essential part of any communication systems, and in the case of multiband wireless communications, tunable multiband RF filters are required for channel selection, noise/interference removal, and RF signal processing. Unfortunately, it is difficult for RF electronics to achieve both tunable and multiband spectral filtering. Recent advancements of microwave photonics have proven itself to be a promising candidate to solve various challenges in RF electronics including spectral filtering, however, the development of multiband microwave photonic filtering still faces lots of difficulties, due to the limited scalability and tunability of existing microwave photonic schemes. In this review paper, we first discuss the challenges that were facing by multiband microwave photonic filter, then we review recent techniques that have been developed to tackle the challenge and lead to promising developments of tunable microwave photonic multiband filters. The successful design and implementation of tunable microwave photonic multiband filter facilitate the vision of dynamic multiband wireless communications and radio frequency signal processing for commercial, defense, and civilian applications.

  4. ALINET: a model for assessing energy conservation opportunities in the food processing industry. Final technical report, September 1977-December 1979

    Energy Technology Data Exchange (ETDEWEB)

    Levis, A H; Ducot, E R; Levis, I S; Webster, T F

    1979-12-01

    ALINET is a network model designed for the analysis of energy use in the food processing and distribution sector and for the evaluation of the potential effectiveness of energy conserving technologies. The conceptual framework of the model, as well as the design and implementation of the computer software are described. The wheat system at the national, state, and facility-specific level is used to illustrate the model's operation and use. A pilot project, carried out in cooperation with industry, is described in which energy use in (a) hard wheat milling, and (b) durum milling and pasta manufacture is analyzed. Finally, the introduction of an alternative technology for pasta drying is assessed in terms of energy conservation and cost. Recommendation for further applications and institutionalization of the model are made.

  5. Experiments on quantum frequency conversion of photons

    International Nuclear Information System (INIS)

    Ramelow, S.

    2011-01-01

    Coherently converting photons between different states offers intriguing new possibilities and applications in quantum optical experiments. In this thesis three experiments on this theme are presented. The first experiment demonstrates the quantum frequency conversion of polarization entangled photons. Coherent frequency conversion of single photons offers an elegant solution for the often difficult trade-off of choosing the optimal photon wavelength, e.g. regarding optimal transmission and storage of photons in quantum memory based quantum networks. In our experiments, we verify the successful entanglement conversion by violating a Clauser-Horne-Shimony-Holt (CHSH) Bell inequality and fully characterised our close to unity fidelity entanglement transfer using quantum state- and process tomography. Our implementation is robust and flexible, making it a practical building block for future quantum technologies.The second part of the thesis introduces a deterministic scheme for photonic quantum information processing. While single photons offer many advantages for quantum information technologies, key unresolved challenges are scalable on-demand single photon sources; deterministic two-photon interactions; and near 100%-efficient detection. All these can be solved with a single versatile process - a novel four-wave mixing process that we introduce here as a special case of the more general scheme of coherent photon conversion (CPC). It can provide valuable photonic quantum processing tools, from scalably creating single- and multi-photon states to implementing deterministic entangling gates and high-efficiency detection. Notably, this would enable scalable photonic quantum computing. Using photonic crystal fibres, we experimentally demonstrate a nonlinear process suited for coherent photon conversion. We observe correlated photon-pair production at the predicted wavelengths and experimentally characterise the enhancement of the interaction strength by varying the pump

  6. One color multi-photon ionization of the Gadolinium atom in near UV region

    International Nuclear Information System (INIS)

    Kim, Jin Tae; Yi, Jong Hoon; Lhee, Yong Joo; Lee, Jong Min

    1999-01-01

    We have investigated the states of the gadolinium atom in near ultra-violet (UV) region (∼410 nm) using single photon excitation using resonance ionization mass spectrometry (RIMS). Around 70 transitions among observed 180 single color multi-photon ionization signals have been assigned. Most of the multi-photon processes of the assigned ion signals are through single photon resonant three photon ionization and through two photon resonant three photon ionization. (author)

  7. Update on photon-photon collisions

    International Nuclear Information System (INIS)

    Arteaga-Romero, N.; Cochard, G.; Ong, S.; Amiens Univ., 80; Carimalo, C.; Kessler, P.; Nicolaidis, A.; Parisi, J.; Courau, A.

    1980-03-01

    This report is the continuation of the 'Update' of last year (L.P.C. 79-03, March 1979, in French). In Part I, the structure functions of the photon in QCD are examined. It is shown that, while large psub(T) hadron production is similar to some extent in γγ collisions and in hadron-hadron collisions, the point-like nature of the photon introduces new terms which are entirely calculable, providing new means to test the dynamics of strong interactions. In Part II, problems of analysis in γγ experiments are discussed. The pros and cons of various options with regard to the measurement of outgoing electrons (non-tagging, finite-angle tagging, tagging at 0 0 ) are compared. It is shown that (a) non-tagging may be applied to the study of a limited number of processes only; (b) finite-angle tagging counters allow for various possibilities (double-tagging, single-tagging, double anti-tagging), but none of them is entirely satisfactory; (c) the ideal measurement is double tagging at 0 0 , provided the problem of bremsstrahlung saturation of the tagging counters can be solved

  8. ENTREPRENEURIAL OPPORTUNITIES IN FOOD PROCESSING UNITS (WITH SPECIAL REFERENCES TO BYADGI RED CHILLI COLD STORAGE UNITS IN THE KARNATAKA STATE

    Directory of Open Access Journals (Sweden)

    P. ISHWARA

    2010-01-01

    Full Text Available After the green revolution, we are now ushering in the evergreen revolution in the country; food processing is an evergreen activity. It is the key to the agricultural sector. In this paper an attempt has been made to study the workings of food processing units with special references to Red Chilli Cold Storage units in the Byadgi district of Karnataka State. Byadgi has been famous for Red Chilli since the days it’s of antiquity. The vast and extensive market yard in Byadagi taluk is famous as the second largest Red Chilli dealing market in the country. However, the most common and recurring problem faced by the farmer is inability to store enough red chilli from one harvest to another. Red chilli that was locally abundant for only a short period of time had to be stored against times of scarcity. In recent years, due to Oleoresin, demand for Red Chilli has grow from other countries like Sri Lanka, Bangladesh, America, Europe, Nepal, Indonesia, Mexico etc. The study reveals that all the cold storage units of the study area have been using vapour compression refrigeration system or method. All entrepreneurs have satisfied with their turnover and profit and they are in a good economic position. Even though the average turnover and profits are increased, few units have shown negligible amount of decrease in turnover and profit. This is due to the competition from increasing number of cold storages and early established units. The cold storages of the study area have been storing Red chilli, Chilli seeds, Chilli powder, Tamarind, Jeera, Dania, Turmeric, Sunflower, Zinger, Channa, Flower seeds etc,. But the 80 per cent of the each cold storage is filled by the red chilli this is due to the existence of vast and extensivered chilli market yard in the Byadgi. There is no business without problems. In the same way the entrepreneurs who are chosen for the study are facing a few problems in their business like skilled labour, technical and management

  9. Development of a Monte Carlo software to photon transportation in voxel structures using graphic processing units; Desenvolvimento de um software de Monte Carlo para transporte de fotons em estruturas de voxels usando unidades de processamento grafico

    Energy Technology Data Exchange (ETDEWEB)

    Bellezzo, Murillo

    2014-09-01

    As the most accurate method to estimate absorbed dose in radiotherapy, Monte Carlo Method (MCM) has been widely used in radiotherapy treatment planning. Nevertheless, its efficiency can be improved for clinical routine applications. In this thesis, the CUBMC code is presented, a GPU-based MC photon transport algorithm for dose calculation under the Compute Unified Device Architecture (CUDA) platform. The simulation of physical events is based on the algorithm used in PENELOPE, and the cross section table used is the one generated by the MATERIAL routine, also present in PENELOPE code. Photons are transported in voxel-based geometries with different compositions. There are two distinct approaches used for transport simulation. The rst of them forces the photon to stop at every voxel frontier, the second one is the Woodcock method, where the photon ignores the existence of borders and travels in homogeneous fictitious media. The CUBMC code aims to be an alternative of Monte Carlo simulator code that, by using the capability of parallel processing of graphics processing units (GPU), provide high performance simulations in low cost compact machines, and thus can be applied in clinical cases and incorporated in treatment planning systems for radiotherapy. (author)

  10. Multi-Level Policy Dialogues, Processes, and Actions: Challenges and Opportunities for National REDD+ Safeguards Measurement, Reporting, and Verification (MRV

    Directory of Open Access Journals (Sweden)

    Pamela Jagger

    2014-09-01

    Full Text Available REDD+ social safeguards have gained increasing attention in numerous forums. This paper reviews the evolution of multi-level policy dialogues, processes, and actions related to REDD+ social safeguards (e.g., Cancun Safeguards 1–5 among policy makers, civil society organizations, and within the media in Brazil, Indonesia and Tanzania, three countries with well advanced REDD+ programs. We find that progress on core aspects of social safeguards is uneven across the three countries. Brazil is by far the most advanced having drafted a REDD+ social safeguards policy. Both Brazil and Indonesia have benefited from progress made by strong sub-national entities in the operationalization of REDD+ safeguards including free prior and informed consent (FPIC, participation, and benefit sharing. Tanzania has weakly articulated how social safeguards will be operationalized and has a more top-down approach. We conclude that in all three countries, measuring, reporting and verifying progress on social safeguards is likely to be a complex issue. Stakeholders with vested interests in REDD+ social safeguards operate in polycentric rather than nested systems, suggesting that aggregation of information from local to national-scale will be a challenge. However, polycentric systems are also likely to support more transparent and comprehensive safeguards systems. Clear direction from the international community and financing for REDD+ safeguard MRV is essential if REDD+ social safeguards are to be meaningfully integrated into forest-based climate mitigation strategies.

  11. Will the Conscious-Subconscious Pacing Quagmire Help Elucidate the Mechanisms of Self-Paced Exercise? New Opportunities in Dual Process Theory and Process Tracing Methods.

    Science.gov (United States)

    Micklewright, Dominic; Kegerreis, Sue; Raglin, John; Hettinga, Florentina

    2017-07-01

    The extent to which athletic pacing decisions are made consciously or subconsciously is a prevailing issue. In this article we discuss why the one-dimensional conscious-subconscious debate that has reigned in the pacing literature has suppressed our understanding of the multidimensional processes that occur in pacing decisions. How do we make our decisions in real-life competitive situations? What information do we use and how do we respond to opponents? These are questions that need to be explored and better understood, using smartly designed experiments. The paper provides clarity about key conscious, preconscious, subconscious and unconscious concepts, terms that have previously been used in conflicting and confusing ways. The potential of dual process theory in articulating multidimensional aspects of intuitive and deliberative decision-making processes is discussed in the context of athletic pacing along with associated process-tracing research methods. In attempting to refine pacing models and improve training strategies and psychological skills for athletes, the dual-process framework could be used to gain a clearer understanding of (1) the situational conditions for which either intuitive or deliberative decisions are optimal; (2) how intuitive and deliberative decisions are biased by things such as perception, emotion and experience; and (3) the underlying cognitive mechanisms such as memory, attention allocation, problem solving and hypothetical thought.

  12. Photon structure and the production of jets, hadrons, and prompt photons

    International Nuclear Information System (INIS)

    Klasen, M.

    1999-01-01

    We give a pedagogical introduction to hard photoproduction processes at HERA, including the production of jets, hadrons, and prompt photons. Recent theoretical developments in the three areas are reviewed. In summary, hard photoproduction processes can provide very useful information on the hadronic structure of the photon, in particular on the gluon density, which is complimentary to the information coming from deep inelastic photon-photon scattering at electron-positron colliders. Among the different hadronic final states, jets are most easily accessible experimentally and phenomenologically. On the other hand, inclusive hadron production offers the possibility to test the universality of hadron fragmentation functions and measure the photon structure down to very low values of p T and x γ . Prompt photon production suffers from a reduced cross section and limited data, but allows for the additional testing of photon fragmentation functions

  13. The photon structure function

    International Nuclear Information System (INIS)

    Berger, C.

    1984-01-01

    In principle we have to distinguish between three cases: In no-tag experiments, none of the outgoing leptons e + e - is detected. The photon flux is completely dominated by transversely polarized photons, which are practically on-mass-shell. In single-tag experiments, either the outgoing e - or e + is detected in a forward spectrometer. Sometimes the tagging information is only used for separating a multihadronic twophoton final state from e + e - annihilation states. On the other hand, the information from the forward detectors can be used to investigate the Q 2 behaviour of the cross-section. A combination of tagging on one side with antitagging on the other allows an easy interpretation of the results in terms of electron scattering off a real photon target. In double-tag experiments, both outgoing leptons are measured. In principle, the full kinematical structure of the process can be studied, but we are still a long way from starting to tackle this difficult task

  14. Nonlinear photonic metasurfaces

    Science.gov (United States)

    Li, Guixin; Zhang, Shuang; Zentgraf, Thomas

    2017-03-01

    Compared with conventional optical elements, 2D photonic metasurfaces, consisting of arrays of antennas with subwavelength thickness (the 'meta-atoms'), enable the manipulation of light-matter interactions on more compact platforms. The use of metasurfaces with spatially varying arrangements of meta-atoms that have subwavelength lateral resolution allows control of the polarization, phase and amplitude of light. Many exotic phenomena have been successfully demonstrated in linear optics; however, to meet the growing demand for the integration of more functionalities into a single optoelectronic circuit, the tailorable nonlinear optical properties of metasurfaces will also need to be exploited. In this Review, we discuss the design of nonlinear photonic metasurfaces — in particular, the criteria for choosing the materials and symmetries of the meta-atoms — for the realization of nonlinear optical chirality, nonlinear geometric Berry phase and nonlinear wavefront engineering. Finally, we survey the application of nonlinear photonic metasurfaces in optical switching and modulation, and we conclude with an outlook on their use for terahertz nonlinear optics and quantum information processing.

  15. Regional Photonics Initiative at the College of Lake County

    Science.gov (United States)

    Dulmes, Steven; Kellerhals, William

    2017-01-01

    The College of Lake County Regional Photonics Initiative project was motivated in part by the hiring of out-of-state technicians for local Photonics industry positions. Fifteen high paying employment opportunities during the recent recession could not be filled from the locally available workforce. Research on the current demand and future growth…

  16. Photonic time crystals.

    Science.gov (United States)

    Zeng, Lunwu; Xu, Jin; Wang, Chengen; Zhang, Jianhua; Zhao, Yuting; Zeng, Jing; Song, Runxia

    2017-12-07

    When space (time) translation symmetry is spontaneously broken, the space crystal (time crystal) forms; when permittivity and permeability periodically vary with space (time), the photonic crystal (photonic time crystal) forms. We proposed the concept of photonic time crystal and rewritten the Maxwell's equations. Utilizing Finite Difference Time Domain (FDTD) method, we simulated electromagnetic wave propagation in photonic time crystal and photonic space-time crystal, the simulation results show that more intensive scatter fields can obtained in photonic time crystal and photonic space-time crystal.

  17. Photon management assisted by surface waves on photonic crystals

    CERN Document Server

    Angelini, Angelo

    2017-01-01

    This book illustrates original pathways to manipulate light at the nanoscale by means of surface electromagnetic waves (here, Bloch surface waves, BSWs) on planar dielectric multilayers, also known as one-dimensional photonic crystals. This approach is particularly valuable as it represents an effective alternative to the widely exploited surface plasmon paradigm. After a brief overview on the fundamentals of BSWs, several significant applications of BSW-sustaining structures are described. Particular consideration is given to the propagation, guiding, and diffraction of BSW-coupled radiation. Further, the interaction of organic emitters with BSWs on planar and corrugated multilayers is investigated, including fluorescence beaming in free space. To provide greater insight into sensing applications, an illustrative example of fluorescent microarray-based detection is presented. The book is intended for scientists and researchers working on photon management opportunities in fields such as biosensing, optical c...

  18. The Brazilian Air Force Uniform Distribution Process: Using Lean Thinking, Statistical Process Control and Theory of Constraints to Address Improvement Opportunities

    Science.gov (United States)

    2015-03-26

    universal definition” (Evans & Lindsay, 1996). Heizer and Render (2010) argue that several definitions of this term are user-based, meaning, that quality...for example, really good ice cream has high butterfat levels.” ( Heizer & Render , 2010). Garvin, in his Competing in Eight Dimensions of Quality...Montgomery, 2005). As for definition purposes, the concept adopted by this research was provided by Heizer and Render (2010), for whom Statistical Process

  19. Jet production in photon-photon interactions

    International Nuclear Information System (INIS)

    Berger, C.; Genzel, H.; Lackas, W.; Pielorz, J.; Raupach, F.; Wagner, W.; Buerger, J.; Criegee, L.; Deuter, A.; Franke, G.; Gerke, C.; Knies, G.; Lewendel, B.; Meyer, J.; Michelsen, U.; Pape, K.H.; Timm, U.; Winter, G.G.; Zimmermann, W.; Zachara, M.; Ferrarotto, F.; Gaspero, M.; Stella, B.; Bussey, P.J.; Cartwright, S.L.; Dainton, J.B.; Hendry, D.; King, B.T.; Raine, C.; Scarr, J.M.; Skillicorn, I.O.; Smith, K.M.; Thomson, J.C.; Achterberg, O.; Blobel, V.; Burkart, D.; Diehlmann, K.; Feindt, M.; Kapitza, H.; Koppitz, B.; Krueger, M.; Poppe, M.; Spitzer, H.; Staa, R. van; Almeida, F.; Baecker, A.; Barreiro, F.; Brandt, S.; Derikum, K.; Grupen, C.; Meyer, H.J.; Mueller, H.; Neumann, B.; Rost, M.; Stupperich, K.; Zech, G.; Alexander, G.; Bella, G.; Gnat, Y.; Grunhaus, J.; Junge, H.; Kraski, K.; Maxeiner, C.; Maxeiner, H.; Meyer, H.; Schmidt, D.

    1987-01-01

    We present results on jet production in γγ interactions where both photons are quasi-real. The invariant masses of the hadronic system are limited to the range 4≤W vis 12 GeV/c 2 . The data approach the Quark-Parton-Model (QPM) expectation at the highest p T jet values (≥4 GeV/c). Jet production at low p T (≤1 GeV/c) can be described by a Vector Dominance derived model. The data also have a component with no apparent jet structure in the range, 1.0≤p T jet ≤4.0 GeV/c which can be described by phase space or by models of the QCD hard scattering processes γγ→qanti qg and γγ→qanti qqanti q. (orig.)

  20. Municipal opportunities

    International Nuclear Information System (INIS)

    Cousens, D.; Chuddy, B.; Gleeson, A.; Leckie, D.; Wahl, K.; McGarry, D.

    1997-01-01

    The panel discussing market opportunities for municipal electric companies was moderated by Markham Mayor Don Cousens. He expressed himself in favour of deregulation and was optimistic about the benefits it will bring to municipal electric utilities and their customers. Barry Chuddy, General Manager of Business Development for TransAlta Energy discussed the advantages of recent cogeneration and district energy for municipal utilities in Ontario and Quebec, and expressed his support for incentive-based regulation based on a level playing field, competitive generation, and a reasonable charge for stranded assets. Toronto City Councillor Dan Leckie described cogeneration and district energy as a tremendous opportunity to reduce the cost of doing business in the city core through local job creation and by keeping money in the local economy. Karl Wahl, General Manager of Hydro Mississauga expressed optimism that the government will move expeditiously toward competition, choice and lower-cost supply. David McGarry, President of Elecsar Engineering of Sarnia spoke about the significant job creating potential that deregulation will bring to the electrical industry. He cited several examples from Ontario and British Columbia

  1. Mid-infrared integrated photonics on silicon: a perspective

    Directory of Open Access Journals (Sweden)

    Lin Hongtao

    2017-12-01

    Full Text Available The emergence of silicon photonics over the past two decades has established silicon as a preferred substrate platform for photonic integration. While most silicon-based photonic components have so far been realized in the near-infrared (near-IR telecommunication bands, the mid-infrared (mid-IR, 2–20-μm wavelength band presents a significant growth opportunity for integrated photonics. In this review, we offer our perspective on the burgeoning field of mid-IR integrated photonics on silicon. A comprehensive survey on the state-of-the-art of key photonic devices such as waveguides, light sources, modulators, and detectors is presented. Furthermore, on-chip spectroscopic chemical sensing is quantitatively analyzed as an example of mid-IR photonic system integration based on these basic building blocks, and the constituent component choices are discussed and contrasted in the context of system performance and integration technologies.

  2. Study of prompt photon and neutral pion production in photon-photon scattering with the OPAL experiment

    CERN Document Server

    Lillich, Joachim

    2003-01-01

    For the first time at LEP the production of prompt photons is studied in the collisions of quasi-real photons using the OPAL data taken at e+e- centre-of mass energies between 183 GeV and 209 GeV. The total inclusive production cross-section for isolated prompt photons in the kinematic range of transverse momentum > 3.0 GeV and the absolut value of pseudorapidity <1 is determined to be (0.32 +- 0.04 (stat) +- 0.04 (sys)) pb. Differential cross-sections are compared to the predictions of a next-to-leading-order (NLO) calculation. In the second part of this thesis inclusive differential neutral pion cross-sections in photon photon collisons are measured. This measurement is an important test of QCD. In addition this process is the main background for prompt photons.

  3. Creating Innovative Opportunities

    DEFF Research Database (Denmark)

    Ljungberg, Daniel; McKelvey, Maureen; Lassen, Astrid Heidemann

    2012-01-01

    This paper develops lessons about how and why the founders and ventures involved in knowledge intensive entrepreneurship (KIE) manage the process of venture creation. The meta-analysis of the 86 case studies is based upon as conceptual model (from a systemic literature review), linked to illustra...... of knowledge networks to create innovative opportunities....

  4. Access to the decision-making process: opportunities for public involvement in the facility decommissioning process of the United States Nuclear Regulatory Commission

    International Nuclear Information System (INIS)

    Cameron, F.X.

    1996-01-01

    This paper discusses recent initiatives taken by the United States Nuclear Regulatory Commission NRC) to effectively involve the public in decommissioning decisions. Initiatives discussed include the Commission's rulemaking to establish the radiological criteria for decommissioning, as well as public involvement methods that have been used on a site-by-site basis. As un example of public involvement, the NRC is currently in the process of developing generic rules on the radiological criteria for the decontamination and decommissioning of NRC-licensed sites. Not only was this proposed rule developed through an extensive and novel approach for public involvement, but it also establishes the basic provisions that will govern public involvement in future NRC decisions on the decommissioning of individual sites. The aim is to provide the public with timely information about all phases of the NRC staff to express concerns and make recommendations. Th NRC recognizes the value and the necessity of effective public involvement in its regulatory activities and has initiated a number of changes to its regulatory program to accomplish this. From the NRC's perspective, it is much easier and less costly to incorporate these mechanisms for public involvement into the regulatory program early in the process, rather than try to add them after considerable public controversy on an action has already been generated. The historical antecedents for initiatives mentioned, as well as 'lessons learned' from prior experience are also discussed. (author)

  5. Photon-photon collisions and photon structure functions at LEP

    CERN Document Server

    Patt, J

    2000-01-01

    The present knowledge of the structure of the photon based on measurements of photon structure functions is discussed. This review covers recent results on QED structure functions and on the hadronic structure function F/sub 2//sup gamma /. (13 refs).

  6. On the validity of the equivalent-photon approximation for virtual photon-photon collisions

    International Nuclear Information System (INIS)

    Carimalo, C.; Kessler, P.; Parisi, J.

    1979-05-01

    For virtual photon-photon collisions in electron storage rings, one derive the equivalent-photon approximation from a helicity treatment, and present it in two forms, involving respectively (i) polarized transverse photons ('transverse-photon approximation') and (ii) unpolarized ones ('Williams-Weizsaecker approximation'). One first postulates the conditions of validity of the approximation on the basis of analytic considerations, and then check them numerically in the case of the process e e → e e μ + μ - . For this check, we consider the completely differentiated cross section as far as approximation (i) is concerned; and in the case of approximation (ii), the cross section differentiated with respect to all variables except the azimuthal angles. The results are given in the form of Tables showing the lower and higher limit of the error involved in the approximation for a large variety of kinematic configurations (i. e., energy losses and scattering angles of both electrons). Those Tables are discussed in detail, and conclusions are drawn as to the applicability of the equivalent-photon approximation to future experiments to be performed with high-energy electron storage rings

  7. Measurement of contributions of diffractive processes to forward photon spectra in pp collisions at $\\sqrt{s}$ = 13 TeV

    CERN Document Server

    The ATLAS collaboration

    2017-01-01

    This note presents a study of the contribution of proton diffractive dissociation to production of forward photons in pp collisions at $\\sqrt{s}$ = 13 TeV with data recorded by the ATLAS and LHCf experiments in a joint effort. The results are based on data collected in 2015 with a corresponding integrated luminosity of 0.191 nb$^{-1}$. The data analysis is based on photon reconstruction in the LHCf-Arm1 detector, as well as on the inner tracking system of the ATLAS detector, which is used to identify diffractive events. In particular, the energy spectrum of photons in the pseudorapidity range of 8.8110.94 is measured for events with no reconstructed charged-particle tracks with $p_T$>100 MeV and |$\\eta$|<2.5. The results are compared to predictions from several hadronic interaction models.

  8. Detecting Dark Photons with Reactor Neutrino Experiments

    Science.gov (United States)

    Park, H. K.

    2017-08-01

    We propose to search for light U (1 ) dark photons, A', produced via kinetically mixing with ordinary photons via the Compton-like process, γ e-→A'e-, in a nuclear reactor and detected by their interactions with the material in the active volumes of reactor neutrino experiments. We derive 95% confidence-level upper limits on ɛ , the A'-γ mixing parameter, ɛ , for dark-photon masses below 1 MeV of ɛ reactors as potential sources of intense fluxes of low-mass dark photons.

  9. Hybrid Integrated Platforms for Silicon Photonics

    Science.gov (United States)

    Liang, Di; Roelkens, Gunther; Baets, Roel; Bowers, John E.

    2010-01-01

    A review of recent progress in hybrid integrated platforms for silicon photonics is presented. Integration of III-V semiconductors onto silicon-on-insulator substrates based on two different bonding techniques is compared, one comprising only inorganic materials, the other technique using an organic bonding agent. Issues such as bonding process and mechanism, bonding strength, uniformity, wafer surface requirement, and stress distribution are studied in detail. The application in silicon photonics to realize high-performance active and passive photonic devices on low-cost silicon wafers is discussed. Hybrid integration is believed to be a promising technology in a variety of applications of silicon photonics.

  10. Hybrid Integrated Platforms for Silicon Photonics

    Directory of Open Access Journals (Sweden)

    John E. Bowers

    2010-03-01

    Full Text Available A review of recent progress in hybrid integrated platforms for silicon photonics is presented. Integration of III-V semiconductors onto silicon-on-insulator substrates based on two different bonding techniques is compared, one comprising only inorganic materials, the other technique using an organic bonding agent. Issues such as bonding process and mechanism, bonding strength, uniformity, wafer surface requirement, and stress distribution are studied in detail. The application in silicon photonics to realize high-performance active and passive photonic devices on low-cost silicon wafers is discussed. Hybrid integration is believed to be a promising technology in a variety of applications of silicon photonics.

  11. Photon and photon reactions: elementary theoretical introduction

    International Nuclear Information System (INIS)

    Diu, B.

    The electromagnetic field and associated quanta, the photons, are simply and briefly studied. The conventional electromagnetism laws are recalled. Fundamental concepts such as gauge invariance, the electromagnetic current conservation, and photon behavior against the internal symmetries of strong interactions are simply introduced. Results and notations are applied to analysis of reactions where photons intervene in initial or final states (photoproduction) within the limits of amplitude properties in the conventional space-time. The helicity and invariant amplitude formalisms are compared [fr

  12. Report on the results of the fiscal 1997 R and D under consignment from NEDO of photon measuring/processing technology (R and D of petroleum production system high-grade measuring/processing technology); 1997 nendo Shin energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku photon keisoku kako gijutsu (sekiyu seisan system kodo keisoku kako gijutsu kenkyu kaihatsu) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The R and D were conducted of high-strength and high-accuracy welding/joining technology using laser, technology to measure and assess the joining state of structures and defects around the surface of structures and inside structures by high accuracy and high resolution, and technology/equipment to generate a laser light source for the tool, which are all required to remarkably enhance safety/reliability of oil drilling facilities working in the severe environment. In fiscal 1997, as the R and D of oil production system high-grade measuring/processing technology, technical study, study of measures to be taken, operating experiment, assessment, examination, etc. were conducted on the following themes: 1) macroscopic processing technology (R and D of high-reliability laser welding technology), 2) non-destructive composition measuring technology (R and D of internal measurement and photoelectron spectroscopy using short-wavelength radiation), 3) tight-focusing all-solid-state laser technology (R and D of fiber laser), 4) tight-focusing all-solid-state laser technology (R and D of high-efficiency laser diode), and 5) comprehensive investigation of phonics engineering (investigation for photon-applied materials processing technology). 256 refs., 205 figs., 18 tabs.

  13. Ionization of a cesium atom by an absorption process involving two photons from a laser beam; Ionisation d'un atome de cesium par un processus d'absorption a deux photons issus d'un faisceau laser

    Energy Technology Data Exchange (ETDEWEB)

    Gontier, Y.; Trahin, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-01-01

    The expression giving the ionisation cross-section of an atom, by an absorption process involving two photons produced from a laser beam, is derived. The non-relativistic case is considered and the dipolar approximation used. The summation over the intermediate states is carried out rigorously by means of a special technique which is described in detail. A method is presented which makes it possible to obtain the numerical solution. (authors) [French] La formule donnant la section efficace d'ionisation d'un atome, par un processus d'absorption mettant en jeu deux photons issus d'un faiseau Laser, est etablie. On se place dans le cas non relativiste et Pon utilise l'approximation dipolaire. La sommation sur les etats intermediaires est effectuee rigoureusement au moyen d'une technique particuliere qui est decrite en detail. On expose une methode permettant d'obtenir la solution numerique. (auteurs)

  14. Spin-photon interface and spin-controlled photon switching in a nanobeam waveguide

    DEFF Research Database (Denmark)

    Javadi, Alisa; Ding, Dapeng; Appel, Martin Hayhurst

    2018-01-01

    Access to the electron spin is at the heart of many protocols for integrated and distributed quantum-information processing [1-4]. For instance, interfacing the spin-state of an electron and a photon can be utilized to perform quantum gates between photons [2,5] or to entangle remote spin states [6......-9]. Ultimately, a quantum network of entangled spins constitutes a new paradigm in quantum optics [1]. Towards this goal, an integrated spin-photon interface would be a major leap forward. Here we demonstrate an efficient and optically programmable interface between the spin of an electron in a quantum dot...... and photons in a nanophotonic waveguide. The spin can be deterministically prepared with a fidelity of 96\\%. Subsequently the system is used to implement a "single-spin photonic switch", where the spin state of the electron directs the flow of photons through the waveguide. The spin-photon interface may...

  15. Physics with photons at the ATLAS experiment

    CERN Document Server

    Pérez-Réale, V

    2008-01-01

    ATLAS is a general-purpose detector due to start operation next year at the Large Hadron Collider (LHC). The LHC will collide pairs of protons at a centre-of-mass energy of 14 TeV, with a bunch-crossing frequency of 40 MHz, and luminosities up to L = 10^34 cm^-2s^-1. The identification of photons is crucial for the study of a number of physics channels, including the search for a Higgs boson decaying to photon pairs, and measurements of direct production of single photons and photon pairs. Events containing true high-p_T photons must be selected with high efficiency, while rejecting the bulk of high-p_T jet events produced with enormously larger rate through QCD processes. The photon--photon and photon--jet channels are interesting in their own right, allowing the study of QCD at high energy. It is also essential to understand these proceses as the dominant background in the search for certain new physics processes, notably the production and decay of Higgs bosons to photon pairs. There are large uncertaintin...

  16. Axion-photon conversion in space and in low symmetrical dielectric crystals

    International Nuclear Information System (INIS)

    Gorelik, V S

    2016-01-01

    The opportunities of axions detection as the result of axion-photon conversion processes in the space and in low symmetrical dielectric crystals are discussed. In accordance with the modern theory predictions, axions are pseudoscalar vacuum particles having very small (0.001-1.0 meV) rest energy. The possibility of axions conversion into photons and vice-versa processes in vacuum at the presence of outer magnetic field has been analyzed before. Pseudoscalar (axion type) modes are existing in some types of crystals. Polar pseudoscalar lattice and exciton modes in low symmetrical crystals are strongly interacted with axions. In this work, optical excitation of axion-type modes in low symmetrical crystals is proposed for observation of axion - photon conversion processes. Instead of outer magnetic field, the crystalline field of such crystals may be used. The experimental schemes for axion-photon conversion processes observation with recording the secondary emission of luminescence, infrared or Stimulated Raman Scattering in some dielectric crystals are discussed. (paper)

  17. Three new bachelors of photonics in Ontario

    Science.gov (United States)

    Nantel, Marc; Beda, Johann; Grevatt, Treena; Chebbi, Brahim; Jessop, Paul; Song, Shaowen

    2004-10-01

    After the introduction in 2001 of community college programs at the Photonics Technician/Technologist levels, the need to cover the photonics educational space at the undergraduate level was addressed. In the last year, three very different new undergraduate degrees in photonics have started to develop in Ontario. These programs are presented in this paper. The Honours B.Sc. in Photonics at Wilfrid Laurier University (Waterloo) will develop a strong understanding of the theory and application of photonics, with practical hands-on exposure to optics, fibre optics, and lasers. This program benefits from the particularity that the department offering it combines both Physics and Computer Science. At McMaster University, the Engineering Physics program will provide students with a broad background in basic Engineering, Mathematics, Electronics, and Semiconductors, as well as an opportunity to pursue Photonics in greater depth and to have that fact recognized in the program designation. The Niagara and Algonquin College Bachelor of Applied Technology in Photonics program is co-op and joint between the two institutions. Emphasis is placed on the applied aspects of the field, with the more hands-on experimental learning taking precedence in the first years and the more advanced theoretical subjects following in the latter years.

  18. Direct photon production and PDF fits reloaded

    NARCIS (Netherlands)

    Campbell, John M.; Rojo, Juan; Slade, Emma; Williams, Ciaran

    2018-01-01

    Direct photon production in hadronic collisions provides a handle on the gluon PDF by means of the QCD Compton scattering process. In this work we revisit the impact of direct photon production on a global PDF analysis, motivated by the recent availability of the next-to-next-to-leading (NNLO)

  19. Thermal effects on the photon mass

    International Nuclear Information System (INIS)

    Woloshyn, R.M.

    1982-09-01

    It is shown that processes of O(αGsub(F)) in which the photon interacts indirectly with the thermal neutrino background dominate electric screening at low temperature. The photon electric mass still comes out to be much smaller than the present experimental limit

  20. Active Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Ek, Sara

    This thesis deals with the fabrication and characterization of active photonic crystal waveguides, realized in III-V semiconductor material with embedded active layers. The platform offering active photonic crystal waveguides has many potential applications. One of these is a compact photonic...... due to photonic crystal dispersion. The observations are explained by the enhancement of net gain by light slow down. Another application based on active photonic crystal waveguides is micro lasers. Measurements on quantum dot micro laser cavities with different mirror configurations and photonic...

  1. Photon statistics characterization of a single-photon source

    International Nuclear Information System (INIS)

    Alleaume, R; Treussart, F; Courty, J-M; Roch, J-F

    2004-01-01

    In a recent experiment, we reported the time-domain intensity noise measurement of a single-photon source relying on single-molecule fluorescence control. In this paper, we present data processing starting from photocount timestamps. The theoretical analytical expression of the time-dependent Mandel parameter Q(T) of an intermittent single-photon source is derived from ON↔OFF dynamics. Finally, source intensity noise analysis, using the Mandel parameter, is quantitatively compared with the usual approach relying on the time autocorrelation function, both methods yielding the same molecular dynamical parameters

  2. EDITORIAL: Photonica 2011: 3rd International School and Conference on Photonics Photonica 2011: 3rd International School and Conference on Photonics

    Science.gov (United States)

    Petrović, Jovana; Stepić, Milutin; Hadžievski, Ljupčo

    2012-04-01

    dedicated to Photonica 2011 held on 29 August-2 September 2011 in Belgrade, Serbia. The conference was attended by 144 participants from 27 countries who gave 132 oral and poster presentations and 24 lectures. The accompanying papers were peer reviewed and 82 were selected for publication. We take this opportunity to gratefully acknowledge the contribution of the reviewers to the quality of this issue. The papers are grouped in accordance with the conference topics, each section opening with an invited paper. The issue begins with papers dedicated to ultra-cold atomic systems that display coherent behaviour analogous to that of light. These well-controlled atomic systems are indispensible workhorses for experiments in quantum optics, which is the topic of the next section. Holography as a concept, measurement tool and technique for fabrication of periodic photonic structures is placed accordingly between fundamental and applied photonics. It is followed by reports on various photonic devices, their modelling and nonlinear phenomena. The progress in constructing these devices largely depends on artificial (composites, metamaterials) and natural optical materials and their processing. This Topical Issue is an original snapshot of the current research in photonics and by no means an extensive survey of the field. While the making of the former has been a challenging task, the compilation of the latter would be indomitable due to the rapid advances in and diversification of photonics research. In accordance with the aims of the conference itself, we hope that the results reported in this Topical Issue of Physica Scripta will serve to inform and to spark the imagination of scientists and engineers exploring or using the principles and products of photonics.

  3. Photon management in two-dimensional disordered media.

    Science.gov (United States)

    Vynck, Kevin; Burresi, Matteo; Riboli, Francesco; Wiersma, Diederik S

    2012-12-01

    Elaborating reliable and versatile strategies for efficient light coupling between free space and thin films is of crucial importance for new technologies in energy efficiency. Nanostructured materials have opened unprecedented opportunities for light management, notably in thin-film solar cells. Efficient coherent light trapping has been accomplished through the careful design of plasmonic nanoparticles and gratings, resonant dielectric particles and photonic crystals. Alternative approaches have used randomly textured surfaces as strong light diffusers to benefit from their broadband and wide-angle properties. Here, we propose a new strategy for photon management in thin films that combines both advantages of an efficient trapping due to coherent optical effects and broadband/wide-angle properties due to disorder. Our approach consists of the excitation of electromagnetic modes formed by multiple light scattering and wave interference in two-dimensional random media. We show, by numerical calculations, that the spectral and angular responses of thin films containing disordered photonic patterns are intimately related to the in-plane light transport process and can be tuned through structural correlations. Our findings, which are applicable to all waves, are particularly suited for improving the absorption efficiency of thin-film solar cells and can provide a new approach for high-extraction-efficiency light-emitting diodes.

  4. Formation of η' mesons in photon-photon collisions

    International Nuclear Information System (INIS)

    Uitert, B.K. van.

    1986-01-01

    This thesis describes an experiment performed at the positron electron storage ring PEP at the Stanford Linear Accelerator Center on the formation of the η' resonance which is observed in its decay mode ρ 0 γ, where the ρ decays into a π + π - pair. Some general features of the relatively new subject of photon-photon physics are introduced. The η' and the coupling of photons to the η' are discussed in the context of the quark model. It is shown how the mixing angle in the nonet of pseudoscalar mesons can be derived from ratios of γγ widths. The kinematics of the two-photon exchange process, the formation of the η' resonance by the two virtual photons and its subsequent electromagnetic decay into ρ 0 γ are discussed. The selected sample of events is used to determine the γγ width of the η' under the conventional assignment J P = 0 - for the η' and J P = 1 - for the ρ. The result is combined with measurements by other experiments to a world average, which is used to determine the mixing angle for the pseudoscalar nonet under various assumptions. The decay angular and energy distributions are investigated in detail. (Auth.)

  5. Photonic crystals: towards nanoscale photonic devices

    National Research Council Canada - National Science Library

    Lourtioz, J.-M

    2005-01-01

    .... From this point of view, the emergence of photonic bandgap materials and photonic crystals at the end of the 1980s can be seen as a revenge to the benefit this time of optics and electromagnetism. In the same way as the periodicity of solid state crystals determines the energy bands and the conduction properties of electrons, the periodical structur...

  6. Hadron induced leptons and photons

    International Nuclear Information System (INIS)

    Cronin, J.W.

    1977-01-01

    A review of direct production of leptons and photons in hadron-hadron collisions is presented. Production of lepton pairs with large mass is well accounted for by the Drell-Yan process. The origin of direct single leptons is principally due to the production of lepton pairs. A dominant source of lepton pairs is at low effective mass, m [de

  7. Continuous Energy Photon Transport Implementation in MCATK

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Terry R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Trahan, Travis John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sweezy, Jeremy Ed [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nolen, Steven Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hughes, Henry Grady [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pritchett-Sheats, Lori A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Werner, Christopher John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-10-31

    The Monte Carlo Application ToolKit (MCATK) code development team has implemented Monte Carlo photon transport into the MCATK software suite. The current particle transport capabilities in MCATK, which process the tracking and collision physics, have been extended to enable tracking of photons using the same continuous energy approximation. We describe the four photoatomic processes implemented, which are coherent scattering, incoherent scattering, pair-production, and photoelectric absorption. The accompanying background, implementation, and verification of these processes will be presented.

  8. Jet and hadron production in photon-photon collisions

    OpenAIRE

    Soldner-Rembold, Stefan

    1999-01-01

    Di-jet and inclusive charged hadron production cross-sections measured in photon-photon collisions by OPAL are compared to NLO pQCD calculations. Jet shapes measured in photon-photon scattering by OPAL, in deep-inelastic ep scattering by H1 and in photon-proton scattering by ZEUS are shown to be consistent in similar kinematic ranges. New results from TOPAZ on prompt photon production in photon-photon interactions are presented.

  9. Photonic crystal pioneer

    Science.gov (United States)

    Anscombe, Nadya

    2011-08-01

    Over the past ten years, Crystal Fiber, now part of NKT Photonics, has been busy commercializing photonic crystal fibre. Nadya Anscombe finds out about the evolution of the technology and its applications.

  10. Photonic Design for Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Kosten, E.; Callahan, D.; Horowitz, K.; Pala, R.; Atwater, H.

    2014-08-28

    We describe photonic design approaches for silicon photovoltaics including i) trapezoidal broadband light trapping structures ii) broadband light trapping with photonic crystal superlattices iii) III-V/Si nanowire arrays designed for broadband light trapping.

  11. Photonic crystal light source

    Science.gov (United States)

    Fleming, James G [Albuquerque, NM; Lin, Shawn-Yu [Albuquerque, NM; Bur, James A [Corrales, NM

    2004-07-27

    A light source is provided by a photonic crystal having an enhanced photonic density-of-states over a band of frequencies and wherein at least one of the dielectric materials of the photonic crystal has a complex dielectric constant, thereby producing enhanced light emission at the band of frequencies when the photonic crystal is heated. The dielectric material can be a metal, such as tungsten. The spectral properties of the light source can be easily tuned by modification of the photonic crystal structure and materials. The photonic crystal light source can be heated electrically or other heating means. The light source can further include additional photonic crystals that exhibit enhanced light emission at a different band of frequencies to provide for color mixing. The photonic crystal light source may have applications in optical telecommunications, information displays, energy conversion, sensors, and other optical applications.

  12. Photon structure function - theory

    International Nuclear Information System (INIS)

    Bardeen, W.A.

    1984-12-01

    The theoretical status of the photon structure function is reviewed. Particular attention is paid to the hadronic mixing problem and the ability of perturbative QCD to make definitive predictions for the photon structure function. 11 references

  13. Polymers for electronic & photonic application

    CERN Document Server

    Wong, C P

    2013-01-01

    The most recent advances in the use of polymeric materials by the electronic industry can be found in Polymers for Electronic and Photonic Applications. This bookprovides in-depth coverage of photoresis for micro-lithography, microelectronic encapsulants and packaging, insulators, dielectrics for multichip packaging,electronic and photonic applications of polymeric materials, among many other topics. Intended for engineers and scientists who design, process, and manufacturemicroelectronic components, this book will also prove useful for hybrid and systems packaging managers who want to be info

  14. FY 2000 report on the results of the research and development project for the photon-aided instrumentation and processing technologies. Research and development of the advanced instrumentation and processing technologies for oil production systems; 2000 nendo photon keisoku kako gijutsu seika hokokusho. Sekiyu seisan system kodo keisoku kako gijutsu kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Described herein are the FY 2000 results of development of the photon-aided instrumentation and processing technologies, as part of development of the advanced instrumentation and processing technologies for oil production systems. The program for the microscopic processing technology combines iodine and YAG laser beams as the high-power laser beams of wavelength of the order of 1{mu}m, in order to realize laser-aided welding of high-quality thick plates, the welding demonstration tests producing good results; improves an in-process monitoring sensor, to confirm its high reliability; and improves size controllability for ultrafine semiconductor particles for development of quantum functional optoelectronic devices, and extends the electric conductivity for production of the transparent conducting films. The program for the non-destructive composition measuring technology develops a light source which produces short wavelength ray of sufficient brightness; produces three-dimensional CT images with a resolution of 2{mu}m, and is developing superconducting X-ray detectors. The program for the high-power all-solid-state laser technology starts development of a rod-type oscillation-controlling laser which can provide mixed operations of CW, pulsed and Q-switched oscillation modes at an average power of 1kW level. The program for the tightly-focusing all-solid-state laser technology develops the prototype of disk type fiber laser using silica fibers of rectangular cross-section, which produces a power of 103W, and starts development of a laser diode. (NEDO)

  15. Thrust distribution of two-jet like events at a photon-photon collider

    International Nuclear Information System (INIS)

    Kanakubo, Fumiko

    1995-01-01

    One of the advantages of using a photon-photon collision with the same helicity is that the continuum qq-bar production is suppressed at the lowest order (α s 0 ). However, the helicity suppression does not take place for the gluon radiation process, and qq-barg can be two-jet like. We evaluate the cross sections of the two-jet like events in a photon-photon collision, and present the thrust distributions. We take into account the QCD effect to all orders in α s in the leading-double-log approximation, and show the suppression due to this effect. The evaluation with the energy and the polarization distributions of the photon suggests that the contaminating photons with the opposite helicity contribute dominantly to the two-jet like process. (author)

  16. Photonic metamaterials

    International Nuclear Information System (INIS)

    Litchinitser, N M; Shalaev, V M

    2008-01-01

    The invention of metamaterials prompts reconsideration of a number of fundamental physical phenomena and enables a variety of unique properties and functionalities. These include negative refractive index, magnetism at optical frequencies, sub-wavelength resolution, ''backward'' phase matching conditions for nonlinear optical processes, and even rendering objects invisible – cloaking. In this brief review, recent progress in basic theory, design, fabrication, characterization, and potential applications of optical metamaterials is discussed

  17. Photon cooperative effect in resonance spectroscopy

    International Nuclear Information System (INIS)

    Veklenko, B.A.

    1998-01-01

    A systematic method is proposed for calculating the density matrix of subsystems interacting with their environment under conditions of thermodynamic equilibrium. The density matrix of photons resonantly interacting with a surrounding gas is calculated. It is shown that use of the Gibbs distribution allows one to completely eliminate inelastic processes from the calculations. A correct account of photon-photon correlators indicates the presence of new cooperative effects. A new branch of the polariton spectrum is predicted, which is due to the presence of excited atoms in the medium. With the help of the density matrix the mean filling numbers of the photon modes are calculated. In terms of wavelengths, we have obtained a generalization of the Planck formula which accounts for photon cooperative phenomena. The manifestation of these effects in kinetic processes is discussed

  18. Coupled Photonic Crystal Cavity Array Laser

    DEFF Research Database (Denmark)

    Schubert, Martin

    in the quadratic lattice. Processing techniques are developed and optimized in order fabricate photonic crystals membranes in gallium arsenide with quantum dots as gain medium and in indium gallium arsenide phosphide with quantum wells as gain medium. Several key issues in process to ensure good quality....... The results are in good agreement with standard coupled mode theory. Also a novel type of photonic crystal structure is proposed called lambda shifted cavity which is a twodimensional photonic crystal laser analog of a VCSEL laser. Detailed measurements of the coupled modes in the photonic crystals...... with quantum dots are carried out. In agreement with a simple gain model the structures do not show stimulated emission. The spectral splitting due to the coupling between single cavities as well as arrays of cavities is studied theoretically and experimentally. Lasing is observed for photonic crystal cavity...

  19. Photon wave function

    OpenAIRE

    Bialynicki-Birula, Iwo

    2005-01-01

    Photon wave function is a controversial concept. Controversies stem from the fact that photon wave functions can not have all the properties of the Schroedinger wave functions of nonrelativistic wave mechanics. Insistence on those properties that, owing to peculiarities of photon dynamics, cannot be rendered, led some physicists to the extreme opinion that the photon wave function does not exist. I reject such a fundamentalist point of view in favor of a more pragmatic approach. In my view, t...

  20. Quantum interface between an atom and a photon

    International Nuclear Information System (INIS)

    Wilk, Tatjana

    2008-02-01

    A single atom strongly coupled to a high-finesse optical cavity is a versatile tool for quantum information processing. Utilized as a single-photon source, it allows one to generate single photons very efficiently in a well de ned spatio-temporal mode. In a first experiment, polarization-control over the photons is shown. A time-resolved two-photon interference experiment proves the indistinguishability of these photons - required in various quantum information processing schemes. Moreover, in a second experiment, entanglement between the polarization of the emitted photon and the population of the atomic Zeeman levels is created. Subsequent state mapping of the atomic state onto another photon results in a pair of polarization-entangled photons emitted one after the other from the cavity. Although these schemes are in principle possible in free space, the cavity boosts the efficiency by several orders of magnitude. (orig.)

  1. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Fogh Olsen, Ole; Sporring, Jon

    2007-01-01

    . To address this problem we introduce a novel photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way we preserve the important illumination features......, while eliminating noise. We call our method diffusion based photon mapping....

  2. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Olsen, Ole Fogh; Sporring, Jon

    2006-01-01

    . To address this problem we introduce a novel photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way we preserve the important illumination features......, while eliminating noise. We call our method diffusion based photon mapping....

  3. Photonic crystal fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Hansen, K P; Nielsen, M D

    2003-01-01

    Photonic crystal fibers having a complex microstructure in the transverse plane constitute a new and promising class of optical fibers. Such fibers can either guide light through total internal reflection or the photonic bandgap effect, In this paper, we review the different types and applications...... of photonic crystal fibers with particular emphasis on recent advances in the field....

  4. (RN) pair production by photons in a hot Maxwellian plasma

    International Nuclear Information System (INIS)

    Haug, E.

    2004-01-01

    The production of electron-positron pairs by photons in the Coulomb Field of electrons and positrons (triplet production) in hot thermal plasmas is investigated. The pair production rate for this process is calculated as a function of the photon energy and compared with the rate of photon-nucleus pair production for semi-relativistic and relativistic plasma temperatures. (author)

  5. EDITORIAL: The next photonic revolution The next photonic revolution

    Science.gov (United States)

    Zheludev, Nikolay I.

    2009-11-01

    dependence upon active and switchable photonic metamaterials and nanophotonic devices. This revolution will lead to dramatic new science and applications on a global scale in all technologies using light, from data storage to optical processing of information, from sensing to light harvesting and energy conversion. Five plenary talks at the conference outlined its topical boundaries. They were given by Sir Michael Berry, Bristol University, UK, who spoke on the new topic of optical super-oscillations; Harry A Atwater, California Institute of Technology, USA, who gave an overview of recent developments in plasmonics; Christian Colliex, Université Paris-Sud, France, who presented the concept of electron energy-loss spectroscopy for the study of localized plasmons; Xiang Zhang, University of California at Berkeley, USA, who talked about recent achievements in the optical super-lens, and Antoinette Taylor, National Laboratory, Los Alamos, USA, who discussed recent work on tunable terahertz metamaterials. In the specially assigned `breakthrough' talks Steven Anlage, University of Maryland, USA, introduced the emerging field of superconducting meta-materials, Tobias Kippenberg, Max-Planck-Institut, Garching, Germany, talked about cavity optomechanics on a chip, while Misha Lukin, Harvard University, USA, explored the field of quantum plasmonics and Victor Prinz, Russian Academy of Science, Russia, introduced a novel class of metamaterials based on three-dimensional semiconductor nanostructures. The topical scope of this special section, to a great extent, echoes the paradigm shift in the NANOMETA community and includes papers on nanofabrication of plasmonic structure, transformation optics and invisibility, mapping of fields in nanostructures, nonlinear and magnetoplasmonic media, coherent effects in metamaterials, loss compensation in nanostructures, slow light and ultrafast switching of plasmon signals, and many other topics. The Guest Editor of this special section and the co

  6. Physics research opportunities with XFEL's

    International Nuclear Information System (INIS)

    Sinha, S. K.

    1999-01-01

    The advent of x-ray Free Electron Lasers will present a number of unique new scientific opportunities. These arise from their special characteristics which include intensely brilliant pulses of x-rays delivered in very short times, complete transverse coherence, and high photon quantum degeneracy, amongst other things. While clearly much thought needs to be given to a detailed quantitative assessment of the feasibility of various experiments using such sources, including methods of dealing with heat loads on beamline optics and radiation damage to samples, there are a number of areas in which one can see new opportunities, and other exciting possibilities about which one might speculate. In this talk the author briefly reviews some of these areas, such as x-ray holography, pump-probe type experiments, correlation spectroscopy and quantum optics experiments with x-rays

  7. Cloud-based opportunities in scientific computing: insights from processing Suomi National Polar-Orbiting Partnership (S-NPP) Direct Broadcast data

    Science.gov (United States)

    Evans, J. D.; Hao, W.; Chettri, S.

    2013-12-01

    The cloud is proving to be a uniquely promising platform for scientific computing. Our experience with processing satellite data using Amazon Web Services highlights several opportunities for enhanced performance, flexibility, and cost effectiveness in the cloud relative to traditional computing -- for example: - Direct readout from a polar-orbiting satellite such as the Suomi National Polar-Orbiting Partnership (S-NPP) requires bursts of processing a few times a day, separated by quiet periods when the satellite is out of receiving range. In the cloud, by starting and stopping virtual machines in minutes, we can marshal significant computing resources quickly when needed, but not pay for them when not needed. To take advantage of this capability, we are automating a data-driven approach to the management of cloud computing resources, in which new data availability triggers the creation of new virtual machines (of variable size and processing power) which last only until the processing workflow is complete. - 'Spot instances' are virtual machines that run as long as one's asking price is higher than the provider's variable spot price. Spot instances can greatly reduce the cost of computing -- for software systems that are engineered to withstand unpredictable interruptions in service (as occurs when a spot price exceeds the asking price). We are implementing an approach to workflow management that allows data processing workflows to resume with minimal delays after temporary spot price spikes. This will allow systems to take full advantage of variably-priced 'utility computing.' - Thanks to virtual machine images, we can easily launch multiple, identical machines differentiated only by 'user data' containing individualized instructions (e.g., to fetch particular datasets or to perform certain workflows or algorithms) This is particularly useful when (as is the case with S-NPP data) we need to launch many very similar machines to process an unpredictable number of

  8. The photon content of the proton

    Science.gov (United States)

    Manohar, Aneesh V.; Nason, Paolo; Salam, Gavin P.; Zanderighi, Giulia

    2017-12-01

    The photon PDF of the proton is needed for precision comparisons of LHC cross sections with theoretical predictions. In a recent paper, we showed how the photon PDF could be determined in terms of the electromagnetic proton structure functions F 2 and F L measured in electron-proton scattering experiments, and gave an explicit formula for the PDF including all terms up to next-to-leading order. In this paper we give details of the derivation. We obtain the photon PDF using the factorisation theorem and applying it to suitable BSM hard scattering processes. We also obtain the same PDF in a process-independent manner using the usual definition of PDFs in terms of light-cone Fourier transforms of products of operators. We show how our method gives an exact representation for the photon PDF in terms of F 2 and F L , valid to all orders in QED and QCD, and including all non-perturbative corrections. This representation is then used to give an explicit formula for the photon PDF to one order higher than our previous result. We also generalise our results to obtain formulæ for the polarised photon PDF, as well as the photon TMDPDF. Using our formula, we derive the P γ i subset of DGLAP splitting functions to order αα s and α 2, which agree with known results. We give a detailed explanation of the approach that we follow to determine a photon PDF and its uncertainty within the above framework.

  9. Prospects for forward photon measurements at LHC

    Directory of Open Access Journals (Sweden)

    van Leeuwen Marco

    2016-01-01

    Full Text Available We present the opportunities to experimentally probe the gluon density at small x in nuclei to explore non-linear gluon evolution, saturation and the physics of the Color Glass Condensate by measuring photon production at forward rapidity in proton-nucleus collisions at the LHC. Performance studies for π0 and direct photon measurements based on simulations of a Forward Calorimeter (FoCal, which is under consideration as an upgrade for the ALICE detector, are presented. Other aspects of the FoCal physics program for pp, p+Pb and Pb+Pb collisions are briefly discussed as well.

  10. Efficient fiber-coupled single-photon source based on quantum dots in a photonic-crystal waveguide

    DEFF Research Database (Denmark)

    Daveau, Raphaël S.; Balram, Krishna C.; Pregnolato, Tommaso

    2017-01-01

    Many photonic quantum information processing applications would benefit from a high brightness, fiber-coupled source of triggered single photons. Here, we present a fiber-coupled photonic-crystal waveguide (PCWG) singlephoton source relying on evanescent coupling of the light field from a tapered...

  11. J/Ψ-production of photon-photon colliders as a probe of the color octet mechanism

    International Nuclear Information System (INIS)

    Ma, J.P.; McKellar, B.H.J.; Paranavitane, C.B

    1997-01-01

    We study J/Ψ production at photon-photon colliders, which can be realised with Compton scattering of laser photons at e + e - colliders. We find that the production rate through the color-octet channel is comparable to that through the color-singlet channel. Experimentally the two mechanisms can be studied separately because the processes have different signals. (authors)

  12. Generation of a multi-photon Greenberger-Horne-Zeilinger state with linear optical elements and photon detectors

    International Nuclear Information System (INIS)

    Zou, X B; Pahlke, K; Mathis, W

    2005-01-01

    We present a scheme to generate a multi-photon Greenberger-Horne-Zeilinger (GHZ) state by using single-photon sources, linear optical elements and photon detectors. Such a maximum entanglement has wide applications in the demonstration of quantum nonlocality and quantum information processing

  13. Silicon Microspheres Photonics

    International Nuclear Information System (INIS)

    Serpenguzel, A.

    2008-01-01

    Electrophotonic integrated circuits (EPICs), or alternatively, optoelectronic integrated circuit (OEICs) are the natural evolution of the microelectronic integrated circuit (IC) with the addition of photonic capabilities. Traditionally, the IC industry has been based on group IV silicon, whereas the photonics industry on group III-V semiconductors. However, silicon based photonic microdevices have been making strands in siliconizing photonics. Silicon microspheres with their high quality factor whispering gallery modes (WGMs), are ideal candidates for wavelength division multiplexing (WDM) applications in the standard near-infrared communication bands. In this work, we will discuss the possibility of using silicon microspheres for photonics applications in the near-infrared

  14. Photon correlation holography.

    Science.gov (United States)

    Naik, Dinesh N; Singh, Rakesh Kumar; Ezawa, Takahiro; Miyamoto, Yoko; Takeda, Mitsuo

    2011-01-17

    Unconventional holography called photon correlation holography is proposed and experimentally demonstrated. Using photon correlation, i.e. intensity correlation or fourth order correlation of optical field, a 3-D image of the object recorded in a hologram is reconstructed stochastically with illumination through a random phase screen. Two different schemes for realizing photon correlation holography are examined by numerical simulations, and the experiment was performed for one of the reconstruction schemes suitable for the experimental proof of the principle. The technique of photon correlation holography provides a new insight into how the information is embedded in the spatial as well as temporal correlation of photons in the stochastic pseudo thermal light.

  15. Qubit-qubit entanglement dynamics control via external classical pumping and Kerr nonlinearity mediated by a single detuned cavity field powered by two-photon processes

    Science.gov (United States)

    Ateto, M. S.

    2017-11-01

    The nonlinear time-dependent two-photon Hamiltonian of a couple of classically pumped independent qubits is analytically solved, and the corresponding time evolution unitary operator, in an exact form, is derived. Using the concurrence, entanglement dynamics between the qubits under the influence of a wide range of effective parameters are examined and, in detail, analyzed. Observations analysis is documented with aid of the field phase-space distribution Wigner function. A couple of initial qubit states is considered, namely similar excited states and a Bell-like pure state. It is demonstrated that an initial Bell-like pure state is as well typical initial qubits setting for robust, regular and a high degree of entanglement. Moreover, it is established that high-constant Kerr media represent an effective tool for generating periodical entanglement at fixed time cycles of maxima reach unity forever when qubits are initially in a Bell-like pure state. Further, it is showed that the medium strength of the classical pumping stimulates efficiently qubits entanglement, specially, when the interaction occurs off resonantly. However, the high-intensity pumping thermalizes the coherent distribution of photons, thus, the least photons number is used and, hence, the least minimum degree of qubits entanglement could be created. Furthermore, when the cavity field and external pumping are detuned, the external pumping acts like an auxiliary effective frequency for the cavity, as a result, the field Gaussian distribution acquires linear chirps, and consequently, more entanglement revivals appear in the same cycle during timescale.

  16. Trace detection of organic compounds in complex sample matrixes by single photon ionization ion trap mass spectrometry: real-time detection of security-relevant compounds and online analysis of the coffee-roasting process.

    Science.gov (United States)

    Schramm, Elisabeth; Kürten, Andreas; Hölzer, Jasper; Mitschke, Stefan; Mühlberger, Fabian; Sklorz, Martin; Wieser, Jochen; Ulrich, Andreas; Pütz, Michael; Schulte-Ladbeck, Rasmus; Schultze, Rainer; Curtius, Joachim; Borrmann, Stephan; Zimmermann, Ralf

    2009-06-01

    An in-house-built ion trap mass spectrometer combined with a soft ionization source has been set up and tested. As ionization source, an electron beam pumped vacuum UV (VUV) excimer lamp (EBEL) was used for single-photon ionization. It was shown that soft ionization allows the reduction of fragmentation of the target analytes and the suppression of most matrix components. Therefore, the combination of photon ionization with the tandem mass spectrometry (MS/MS) capability of an ion trap yields a powerful tool for molecular ion peak detection and identification of organic trace compounds in complex matrixes. This setup was successfully tested for two different applications. The first one is the detection of security-relevant substances like explosives, narcotics, and chemical warfare agents. One test substance from each of these groups was chosen and detected successfully with single photon ionization ion trap mass spectrometry (SPI-ITMS) MS/MS measurements. Additionally, first tests were performed, demonstrating that this method is not influenced by matrix compounds. The second field of application is the detection of process gases. Here, exhaust gas from coffee roasting was analyzed in real time, and some of its compounds were identified using MS/MS studies.

  17. Two-dimensional topological photonic systems

    Science.gov (United States)

    Sun, Xiao-Chen; He, Cheng; Liu, Xiao-Ping; Lu, Ming-Hui; Zhu, Shi-Ning; Chen, Yan-Feng

    2017-09-01

    The topological phase of matter, originally proposed and first demonstrated in fermionic electronic systems, has drawn considerable research attention in the past decades due to its robust transport of edge states and its potential with respect to future quantum information, communication, and computation. Recently, searching for such a unique material phase in bosonic systems has become a hot research topic worldwide. So far, many bosonic topological models and methods for realizing them have been discovered in photonic systems, acoustic systems, mechanical systems, etc. These discoveries have certainly yielded vast opportunities in designing material phases and related properties in the topological domain. In this review, we first focus on some of the representative photonic topological models and employ the underlying Dirac model to analyze the edge states and geometric phase. On the basis of these models, three common types of two-dimensional topological photonic systems are discussed: 1) photonic quantum Hall effect with broken time-reversal symmetry; 2) photonic topological insulator and the associated pseudo-time-reversal symmetry-protected mechanism; 3) time/space periodically modulated photonic Floquet topological insulator. Finally, we provide a summary and extension of this emerging field, including a brief introduction to the Weyl point in three-dimensional systems.

  18. Electron and Photon ID

    CERN Document Server

    Hryn'ova, Tetiana; The ATLAS collaboration

    2017-01-01

    The identification of prompt photons and the rejection of background coming mostly from photons from hadron decays relies on the high granularity of the ATLAS calorimeter. The electron identification used in ATLAS for run 2 is based on a likelihood discrimination to separate isolated electron candidates from candidates originating from photon conversions, hadron misidentification and heavy flavor decays. In addition, isolation variables are used as further handles to separate signal and background. Several methods are used to measure with data the efficiency of the photon identification requirements, to cover a broad energy spectrum. At low energy, photons from radiative Z decays are used. In the medium energy range, similarities between electrons and photon showers are exploited using Z->ee decays. At high energy, inclusive photon samples are used. The measurement of the efficiencies of the electron identification and isolation cuts are performed with the data using tag and probe techniques with large statis...

  19. Topological photonic orbital-angular-momentum switch

    Science.gov (United States)

    Luo, Xi-Wang; Zhang, Chuanwei; Guo, Guang-Can; Zhou, Zheng-Wei

    2018-04-01

    The large number of available orbital-angular-momentum (OAM) states of photons provides a unique resource for many important applications in quantum information and optical communications. However, conventional OAM switching devices usually rely on precise parameter control and are limited by slow switching rate and low efficiency. Here we propose a robust, fast, and efficient photonic OAM switch device based on a topological process, where photons are adiabatically pumped to a target OAM state on demand. Such topological OAM pumping can be realized through manipulating photons in a few degenerate main cavities and involves only a limited number of optical elements. A large change of OAM at ˜10q can be realized with only q degenerate main cavities and at most 5 q pumping cycles. The topological photonic OAM switch may become a powerful device for broad applications in many different fields and motivate a topological design of conventional optical devices.

  20. Programmable Quantum Photonic Processor Using Silicon Photonics

    Science.gov (United States)

    2017-04-01

    8 Figure 6: (a) Proposed on-demand single photon source based on dynamic cavity storage . (b) Example of a gate implementation...electronic architectures tuned to implement artificial neural networks that improve upon both computational speed and energy efficiency. 3.6 All...states are in the dual- rail logic representation. Approved for Public Release; Distribution Unlimited. 6 Figure 3: Schematic of two-photon

  1. The strategic research agenda of the Technology Platform Photonics21: European component industry for broadband communications and the FP 7

    Science.gov (United States)

    Thylén, Lars

    2006-07-01

    The design and manufacture of components and systems underpin the European and indeed worldwide photonics industry. Optical materials and photonic components serve as the basis for systems building at different levels of complexity. In most cases, they perform a key function and dictate the performance of these systems. New products and processes will generate economic activity for the European photonics industry into the 21 st century. However, progress will rely on Europe's ability to develop new and better materials, components and systems. To achieve success, photonic components and systems must: •be reliable and inexpensive •be generic and adaptable •offer superior functionality •be innovative and protected by Intellectual Property •be aligned to market opportunities The challenge in the short-, medium-, and long-term is to put a coordinating framework in place which will make the European activity in this technology area competitive as compared to those in the US and Asia. In the short term the aim should be to facilitate the vibrant and profitable European photonics industry to further develop its ability to commercialize advances in photonic related technologies. In the medium and longer terms the objective must be to place renewed emphasis on materials research and the design and manufacturing of key components and systems to form the critical link between science endeavour and commercial success. All these general issues are highly relevant for the component intensive broadband communications industry. Also relevant for this development is the convergence of data and telecom, where the low cost of data com meets with the high reliability requirements of telecom. The text below is to a degree taken form the Strategic Research Agenda of the Technology Platform Photonics 21 [1], as this contains a concerted effort to iron out a strategy for EU in the area of photonics components and systems.

  2. Nonlinear silicon photonics

    Science.gov (United States)

    Borghi, M.; Castellan, C.; Signorini, S.; Trenti, A.; Pavesi, L.

    2017-09-01

    Silicon photonics is a technology based on fabricating integrated optical circuits by using the same paradigms as the dominant electronics industry. After twenty years of fervid development, silicon photonics is entering the market with low cost, high performance and mass-manufacturable optical devices. Until now, most silicon photonic devices have been based on linear optical effects, despite the many phenomenologies associated with nonlinear optics in both bulk materials and integrated waveguides. Silicon and silicon-based materials have strong optical nonlinearities which are enhanced in integrated devices by the small cross-section of the high-index contrast silicon waveguides or photonic crystals. Here the photons are made to strongly interact with the medium where they propagate. This is the central argument of nonlinear silicon photonics. It is the aim of this review to describe the state-of-the-art in the field. Starting from the basic nonlinearities in a silicon waveguide or in optical resonator geometries, many phenomena and applications are described—including frequency generation, frequency conversion, frequency-comb generation, supercontinuum generation, soliton formation, temporal imaging and time lensing, Raman lasing, and comb spectroscopy. Emerging quantum photonics applications, such as entangled photon sources, heralded single-photon sources and integrated quantum photonic circuits are also addressed at the end of this review.

  3. Range detection using entangled optical photons

    Science.gov (United States)

    Brandsema, Matthew J.; Narayanan, Ram M.; Lanzagorta, Marco

    2015-05-01

    Quantum radar is an emerging field that shows a lot of promise in providing significantly improved resolution compared to its classical radar counterpart. The key to this kind of resolution lies in the correlations created from the entanglement of the photons being used. Currently, the technology available only supports quantum radar implementation and validation in the optical regime, as opposed to the microwave regime, because microwave photons have very low energy compared to optical photons. Furthermore, there currently do not exist practical single photon detectors and generators in the microwave spectrum. Viable applications in the optical regime include deep sea target detection and high resolution detection in space. In this paper, we propose a conceptual architecture of a quantum radar which uses entangled optical photons based on Spontaneous Parametric Down Conversion (SPDC) methods. After the entangled photons are created and emerge from the crystal, the idler photon is detected very shortly thereafter. At the same time, the signal photon is sent out towards the target and upon its reflection will impinge on the detector of the radar. From these two measurements, correlation data processing is done to obtain the distance of the target away from the radar. Various simulations are then shown to display the resolution that is possible.

  4. FY 2000 report on the results of the research and development project for the photon-aided instrumentation and processing technologies. R and D of the high-performance maintenance technologies for power generation plants; 2000 nendo photon keisoku kako gijutsu seika hokokusho. Hatsuden shisetsuyo kokino maintenance gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Described herein are the FY 2000 results of development of the photon-aided instrumentation and processing technologies, as part of the R and D of the high-performance maintenance technologies for power generation plants. Production of the fine, functional circuits is studied for microscopic processing technology. The light source with variable wavelength-in a range of 2 to 5{mu}m for the solid-state laser, to measure concentration and composition of gases by the infrared absorption laser. The photon wave front compensator is being developed, to prevent disturbance-induced sensitivity deterioration for measurement of high temperature by the laser-aided ultrasonic instrumentation. The prototype of superconducting X-ray detector is developed, for high-sensitivity detection of impurities by measuring fluorescent X-ray. Development of the 10kW-class solid-state, rod-type laser is started for high-speed, high-precision laser-aided welding and cutting, and output of 11.3kW and electrical/optical conversion efficiency of 21.5% are achieved. An electrical/optical conversion efficiency of 17% is also achieved with the slab-type laser. An all-solid-state laser is being developed. It will produce high-energy pulses and high-quality beams capable of generating the beams which are converged very finely on the work with an average output power of 1KW (fundamental wave) and electrical/optical conversion efficiency of at least 20%. (NEDO)

  5. FENDL/MG-2.0 and FENDL/MC-2.0. The processed cross-section libraries for neutron photon transport calculations. Version 1, March 1997. Summary documentation

    International Nuclear Information System (INIS)

    Wienke, H.; Herman, M.

    1998-01-01

    Evaluated neutron reaction data and photon-atom interaction cross sections for materials contained in the general purpose Fusion Evaluated Nuclear Data Library (FENDL/E2.0) have been processed with the NJOY code system into VITAMIN-J multigroup structure, for use in discrete-ordinates transport codes, and into continuous energy ACE format, for use in the Monte Carlo transport code MCNP. This document summarizes the resulting data libraries FENDL/MG-2.0 version 1 and FENDL/MC-2.0 version 1. The data are available costfree from the IAEA Nuclear Data Section online or on magnetic tape. (author)

  6. Quantum optics. All-optical routing of single photons by a one-atom switch controlled by a single photon.

    Science.gov (United States)

    Shomroni, Itay; Rosenblum, Serge; Lovsky, Yulia; Bechler, Orel; Guendelman, Gabriel; Dayan, Barak

    2014-08-22

    The prospect of quantum networks, in which quantum information is carried by single photons in photonic circuits, has long been the driving force behind the effort to achieve all-optical routing of single photons. We realized a single-photon-activated switch capable of routing a photon from any of its two inputs to any of its two outputs. Our device is based on a single atom coupled to a fiber-coupled, chip-based microresonator. A single reflected control photon toggles the switch from high reflection (R ~ 65%) to high transmission (T ~ 90%), with an average of ~1.5 control photons per switching event (~3, including linear losses). No additional control fields are required. The control and target photons are both in-fiber and practically identical, making this scheme compatible with scalable architectures for quantum information processing. Copyright © 2014, American Association for the Advancement of Science.

  7. Five-photon ionization of atomic hydrogen at wavelengths around the threshold for four-photon ionization

    International Nuclear Information System (INIS)

    Gontier, Y.; Trahin, M.; Wolff-Rottke, B.; Rottke, H.; Welge, K.H.; Feldmann, D.

    1992-01-01

    Theoretical and experimental studies show the strong influence of the three-photon nearly resonant 2p state on four- and five-photon ionization of atomic hydrogen near the threshold for four-photon ionization. Changes in five-photon ionization occur when the four-photon ionization channel opens. The angular distributions of photoelectrons from five-photon ionization of H are studied at five wavelengths which cover the range from four-photon resonance with high-lying Rydberg states (n≥10) to direct four-photon ionization into the continuum. The role of resonances in this ionization process is discussed. A fair agreement is found in comparing experimental and theoretical results

  8. Ordered photonic microstructures

    Science.gov (United States)

    Chen, Kevin Ming

    2001-09-01

    This thesis examines novel photonic materials systems possessing order in the atomic, microscopic, and macroscopic dimensional regimes. In the atomic order regime, a structure-property investigation is done for Er2O3 in which the first report of room temperature photoluminescence (PL) is provided. Thin films of the rare earth oxide were deposited via reactive sputtering of Er metal in an Ar/O2 ambient, and subsequently annealed to promote grain growth. Heat treatment consisting of a 650°C followed by 1000°C anneal produces maximum crystallinity as measured by glancing angle x-ray diffraction. These films show characteristic PL at λ = 1.54 μm. In the microscopic order regime, omnidirectional reflectors and thin film microcavities are demonstrated using sol-gel and solid-state materials. A first demonstration of omnidirectional reflectivity in sol-gel structures was accomplished using a dielectric stack consisting of 12 spin-on SiO 2/TiO2 quarterwave sol-gel films. Similarly, solid-state dielectric stacks consisting of 6 Si/SiO2 sputtered films were used to demonstrate the same principle. Microcavities were formed using solgel structures, producing a low quality factor Q = 35 due to limitations in film thickness control and lossy interfaces from stress-induced cracks. The high index contrast Si/SiO2 microcavities enabled Q ~ 1000 using 17 total layers following hydrogenation of dangling bonds within the amorphous Si films. Combining fabrication processes for the solid-state microcavity and Er2O3 films, a device was fabricated to demonstrate photoluminescence enhancement of an Er2O3 film embedded in a microcavity. The structure consisted of 3-bilayer mirrors on either side of an SiO2/Er2O3/SiO2 cavity. The Q ~ 300 was near the theoretical value for such a structure. At room temperature, PL of Er2O3 was enhanced by a factor of 1000 in the microcavity compared to a single thin film. In the macroscopic order regime, self-assembly of micron- sized SiO 2 and

  9. Efficient quantum computing using coherent photon conversion.

    Science.gov (United States)

    Langford, N K; Ramelow, S; Prevedel, R; Munro, W J; Milburn, G J; Zeilinger, A

    2011-10-12

    Single photons are excellent quantum information carriers: they were used in the earliest demonstrations of entanglement and in the production of the highest-quality entanglement reported so far. However, current schemes for preparing, processing and measuring them are inefficient. For example, down-conversion provides heralded, but randomly timed, single photons, and linear optics gates are inherently probabilistic. Here we introduce a deterministic process--coherent photon conversion (CPC)--that provides a new way to generate and process complex, multiquanta states for photonic quantum information applications. The technique uses classically pumped nonlinearities to induce coherent oscillations between orthogonal states of multiple quantum excitations. One example of CPC, based on a pumped four-wave-mixing interaction, is shown to yield a single, versatile process that provides a full set of photonic quantum processing tools. This set satisfies the DiVincenzo criteria for a scalable quantum computing architecture, including deterministic multiqubit entanglement gates (based on a novel form of photon-photon interaction), high-quality heralded single- and multiphoton states free from higher-order imperfections, and robust, high-efficiency detection. It can also be used to produce heralded multiphoton entanglement, create optically switchable quantum circuits and implement an improved form of down-conversion with reduced higher-order effects. Such tools are valuable building blocks for many quantum-enabled technologies. Finally, using photonic crystal fibres we experimentally demonstrate quantum correlations arising from a four-colour nonlinear process suitable for CPC and use these measurements to study the feasibility of reaching the deterministic regime with current technology. Our scheme, which is based on interacting bosonic fields, is not restricted to optical systems but could also be implemented in optomechanical, electromechanical and superconducting

  10. Single-photon imaging

    CERN Document Server

    Seitz, Peter

    2011-01-01

    The acquisition and interpretation of images is a central capability in almost all scientific and technological domains. In particular, the acquisition of electromagnetic radiation, in the form of visible light, UV, infrared, X-ray, etc. is of enormous practical importance. The ultimate sensitivity in electronic imaging is the detection of individual photons. With this book, the first comprehensive review of all aspects of single-photon electronic imaging has been created. Topics include theoretical basics, semiconductor fabrication, single-photon detection principles, imager design and applications of different spectral domains. Today, the solid-state fabrication capabilities for several types of image sensors has advanced to a point, where uncoooled single-photon electronic imaging will soon become a consumer product. This book is giving a specialist´s view from different domains to the forthcoming “single-photon imaging” revolution. The various aspects of single-photon imaging are treated by internati...

  11. Heavy quark pair production in polarized photon-photon collisions

    International Nuclear Information System (INIS)

    Jikia, G.; Tkabladze, A.

    2000-04-01

    We present the cross sections of the heavy quark-antiquark pair production in polarized photon photon collision for the general case of photon polarizations. The numerical results for top-antitop production cross sections together with production asymmetries are obtained for linearly polarized photon-photon collisions, including QCD radiative corrections. (orig.)

  12. Pion pair production in photon-photon interactions

    International Nuclear Information System (INIS)

    Berger, C.; Deuter, A.; Genzel, H.; Lackas, W.; Pielorz, J.; Raupach, F.; Wagner, W.; Bussey, P.J.; Cartwright, S.L.; Dainton, J.B.; King, B.T.; Raine, C.; Scarr, J.M.; Skillikorn, I.O.; Smith, K.M.; Thomson, J.C.; Achterberg, O.; Blobel, V.; Burkart, D.; Diehlmann, K.; Feindt, M.; Kapitza, H.; Koppitz, B.; Krueger, M.; Poppe, M.; Spitzer, H.; Staa, R. van; Almeida, F.; Baecker, A.; Barreiro, F.; Brandt, S.; Derikum, K.; Grupen, C.; Meyer, H.J.; Mueller, H.; Neumann, B.; Rost, M.; Stupperich, K.; Zech, G.; Alexander, G.; Bella, G.; Gnat, Y.; Grunhaus, J.; Junge, H.; Kraski, K.; Maxeiner, C.; Maxeiner, H.; Meyer, H.; Schmidt, D.; Buerger, J.; Criegee, L.; Ferrarotto, F.; Franke, G.; Gaspero, M.; Gerke, C.; Knies, G.; Lewendel, B.; Meyer, J.; Michelsen, U.; Pape, K.H.; Stella, B.; Timm, U.; Winter, G.G.; Zachara, M.; Zimmermann, W.

    1984-08-01

    The process γγ -> π + π - has been measured with complete particle identification. Cross-sections are presented from near threshold up to the region of the f(1270). In the mass range 0.5-0.7 GeV, cross-sections are lower than the Born term predictions and show no evidence for an epsilon(600). The two-photon width of the f(1270) is found to be in agreement with previous results. (orig.)

  13. Quartz substrate infrared photonic crystal

    Science.gov (United States)

    Ghadiri, Khosrow; Rejeb, Jalel; Vitchev, Vladimir N.

    2003-01-01

    This paper presents the fabrication of a planar photonic crystal (p2c) made of a square array of dielectric rods embedded in air, operating in the infrared spectrum. A quartz substrate is employed instead of the commonly used silicon or column III-V substrate. Our square structure has a normalized cylinder radius-to-pitch ratio of r/a = 0.248 and dielectric material contrast ɛr of 4.5. We choose a Z-cut synthetic quartz for its cut (geometry), and etching properties. Then a particular Z-axis etching process is employed in order to ensure the sharp-edged verticality of the rods and fast etching speed. We also present the computer simulations that allowed the establishment of the photonic band gaps (PBG) of our photonic crystal, as well as the actual measurements. An experimental measurement have been carried out and compared with different simulations. It was found that experimental results are in good agreement with different simulation results. Finally, a frequency selective device for optical communication based on the introduction of impurity sites in the photonic crystal is presented. With our proposed structure Optical System on a Chip (OsoC) with micro-cavity based active devices such as lasers, diodes, modulators, couplers, frequency selective emitters, add-drop filters, detectors, mux/demuxes and polarizers connected by passive waveguide links can be realized.

  14. Manipulating light with strongly modulated photonic crystals

    International Nuclear Information System (INIS)

    Notomi, Masaya

    2010-01-01

    Recently, strongly modulated photonic crystals, fabricated by the state-of-the-art semiconductor nanofabrication process, have realized various novel optical properties. This paper describes the way in which they differ from other optical media, and clarifies what they can do. In particular, three important issues are considered: light confinement, frequency dispersion and spatial dispersion. First, I describe the latest status and impact of ultra-strong light confinement in a wavelength-cubic volume achieved in photonic crystals. Second, the extreme reduction in the speed of light is reported, which was achieved as a result of frequency dispersion management. Third, strange negative refraction in photonic crystals is introduced, which results from their unique spatial dispersion, and it is clarified how this leads to perfect imaging. The last two sections are devoted to applications of these novel properties. First, I report the fact that strong light confinement and huge light-matter interaction enhancement make strongly modulated photonic crystals promising for on-chip all-optical processing, and present several examples including all-optical switches/memories and optical logics. As a second application, it is shown that the strong light confinement and slow light in strongly modulated photonic crystals enable the adiabatic tuning of light, which leads to various novel ways of controlling light, such as adiabatic frequency conversion, efficient optomechanics systems, photon memories and photons pinning.

  15. Communicating Science Through Participating In Process: The Challenges And Opportunities For Scientists To Participate In Policy Development - An Example From New Zealand

    Science.gov (United States)

    Saunders, W. S. A.; Van Dissen, R. J.

    2016-12-01

    `It's Our Fault' (IOF) is an end-to-end research programme aimed at positioning Wellington, the capital city of New Zealand, to become a more resilient city through a comprehensive study of the likelihood of large Wellington earthquakes, the effects of these earthquakes, and their impacts on humans and the built environment. For over 10 years the IOF programme has facilitated end-user engagement, and produced a great number of publications on the results of the hazard and risk research. Nevertheless, much of this research was not being applied to local council policies being formulated to intensify development in one of the most susceptible locations in the Wellington region. We explore why this was the case, and offer suggestions on how to bridge the gap between science and practice.The example is a statutory plan change which allowed for an increased level of development and encouraged mixed-use development in a location of high susceptibility from multiple hazards including fault rupture, ground shaking, subsidence, sea level rise, liquefaction, flooding, and tsunami. Prior to the plan change, the land use was predominantly business and commercial; this plan change proposed introducing residential, educational and emergency facilities, thereby increasing exposure within an area already known to be "risky". Being a good `corporate citizen' of the city involved, GNS Science lodged a submission opposing the plan change based on the range of natural hazards that were not addressed in the plan change. Scientists were involved in public meetings, met with the Mayor, and attended a hearing. While the plan change still went ahead, natural hazard provisions were improved through the submission process. Many aspects of the submission were based around communicating the natural hazard research undertaken within the IOF project.Land use planning provides a key opportunity to reduce future risks from natural hazards, and scientist have a key role in contributing to

  16. Review on Dark Photon

    Directory of Open Access Journals (Sweden)

    Curciarello Francesca

    2016-01-01

    Full Text Available e+e− collider experiments at the intensity frontier are naturally suited to probe the existence of a force beyond the Standard Model between WIMPs, the most viable dark matter candidates. The mediator of this new force, known as dark photon, should be a new vector gauge boson very weakly coupled to the Standard Model photon. No significant signal has been observed so far. I will report on current limits set on the coupling factor ε2 between the photon and the dark photon by e+e− collider experiments.

  17. Towards THz integrated photonics

    OpenAIRE

    Hübers, Heinz-Wilhelm

    2010-01-01

    The demonstration of an integrated terahertz transceiver featuring a quantum cascade laser and a Schottky diode mixer promises new applications for compact and convenient terahertz photonic instrumentation.

  18. Tale of two photons

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    A very profitable spinoff from electron- positron collisions is two-photon physics. Rather than the electron and positron interacting directly via an exchanged photon, two virtual (transient) photons, one from each particle, get tangled up. With new electron-positron colliders appearing on the scene, a topical meeting on two-photon physics - 'From DAPHNE to LEP 200 and beyond' - held from 2-4 February in Paris, in the premises of the Ministry of Higher Education and Research, was particularly timely. Some 60 physicists, both experimentalists and theorists, participated, with some thirty speakers

  19. Advanced Photon Source (APS)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Photon Source (APS) at the U.S. Department of Energy's Argonne National Laboratoryprovides this nation's (in fact, this hemisphere's) brightest storage...

  20. Single photon emission tomography

    International Nuclear Information System (INIS)

    Buvat, Irene

    2011-09-01

    The objective of this lecture is to present the single photon emission computed tomography (SPECT) imaging technique. Content: 1 - Introduction: anatomic, functional and molecular imaging; Principle and role of functional or molecular imaging; 2 - Radiotracers: chemical and physical constraints, main emitters, radioisotopes production, emitters type and imaging techniques; 3 - Single photon emission computed tomography: gamma cameras and their components, gamma camera specifications, planar single photon imaging characteristics, gamma camera and tomography; 4 - Quantification in single photon emission tomography: attenuation, scattering, un-stationary spatial resolution, partial volume effect, movements, others; 5 - Synthesis and conclusion