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Sample records for wakefield melanie cv

  1. Use of MELANIE

    International Nuclear Information System (INIS)

    Lanfranchi, M.

    1987-09-01

    MELANIE allows to calculate, with a minimum of simple instructions, the transport of neutrons and gammas in slab, spherical and cylindrical geometry. MELANIE has several libraries of microscopic group cross sections. The preparation of macroscopic cross sections is trivial whatever is number of groups, energy regions, order of developments of Legendre, etc. Geometry and sources are defined through elementary instructions which permit the choice of continuous or discrete spectrum, independently of the group structure. The transport calculation is done by well-known codes, e.g. ANISN and SURCU, for which MELANIE manages the input and output. Input to MELANIE is elementary because the code defines, instead of the user, the best choice of parameters and appropriate options. Adequate commands permit to modify them if necessary. MELANIE is enclosed by peripheral programs which permit to obtain information such as fluxes in different energy regions, doses, heat production, etc., in form of tables and graphs. The version MELANIE 7 described here is built in the system RSYST. An independent version is in preparation. MELANIE permits to save time for preparation of input. Its great flexibility of input and output makes it a modern code. 1 ref., 1 tab

  2. [Meenutusi koolist] / Melanie Jakobs

    Index Scriptorium Estoniae

    Jakobs, Melanie

    2010-01-01

    Tallinna Ehitus- ja Mehaanikatehnikumi (praegu Tallinna Tehnikakõrgkool) õppejõu Melanie Jakobsi mälestused töökaitse- ja tuleohutuse kabineti juures tegutsenud noortuletõrjujate salga tegevusest aastatel 1981-1990

  3. Erna and Melanie Klein.

    Science.gov (United States)

    Tabak de Bianchedi, Elizabeth; Etchegoyen, R Horacio; Ungar de Moreno, Virginia; Nemas de Urman, Clara; Zysman, Samuel

    2003-12-01

    Erna was one of the child patients treated by Melanie Klein in Berlin, employing her recently discovered play technique. Since Erna died in Chile, the authors considered the IPA Congress in Santiago an opportunity to present a paper as a homage both to Erna and, especially, to Klein. She learned much from that very disturbed child, which she later used to sustain the ongoing development of her theories. The paper explores biographic data relevant to understanding both the case and the theories. It analyses the case material to follow Klein in the discovery and the handling of the child's transference and the harsh expressions of hate, jealousy and envy, which are brought in, with sad consequences, by strong persecutory feelings. Klein's comparison of this case with that of Freud's Wolf-man is also considered, mostly to show that the similarities were less than originally claimed, and that Klein, perhaps, was introducing a theoretic shift which led her technique to gradually change from 'Nachträglichkeit' to the 'signification-resignification' pair, akin to Strachey's concept of the mutative interpretation. Lastly, the comprehension of Erna's strong psychotic traits and the links with later developments of the theory on psychosis are studied.

  4. Dielectric Wakefield Researches

    International Nuclear Information System (INIS)

    Kiselev, V.A.; Linnik, A.F.; Onishchenko, N.I.; Uskov, V.V.; Marshall, T.C.

    2006-01-01

    Excitation of wakefield in cylindrical dielectric waveguide/resonator by a sequence of relativistic electron bunches was investigated using an electron linac 'Almaz-2' (4.5 MeV, 6·10 3 bunches of duration 60 ps and charge 0.32 nC each). Energy spectrum of electrons, radial topography and longitudinal distribution of wakefield, and total energy of excited wakefield were measured by means of magnetic analyzer, high frequency probe, and a sensitive calorimeter

  5. Argonne Wakefield Accelerator Update '92

    International Nuclear Information System (INIS)

    Rosing, M.; Balka, L.; Chojnacki, E.; Gai, W.; Ho, C.; Konecny, R.; Power, J.; Schoessow, P.; Simpson, J.

    1992-01-01

    The Argonne Wakefield Accelerator (AWA) is an experiment designed to test various ideas related to wakefield technology. Construction is now underway for a 100 nC electron beam in December of 1992. This report updates this progress

  6. Laser wakefield acceleration

    International Nuclear Information System (INIS)

    Esarey, E.; Ting, A.; Sprangle, P.

    1989-01-01

    The laser wakefield accelerator (LWFA) is a novel plasma based electron acceleration scheme which utilizes a relativistic optical guiding mechanism for laser pulse propagation. In the LWFA, a short, high power, single frequency laser pulse is propagated through a plasma. As the laser pulse propagates, its radial and axial ponderomotive forces nonresonantly generate large amplitude plasma waves (wakefields) with a phase velocity equal to the group velocity of the pulse. A properly phased electron bunch may then be accelerated by the axial wakefield and focused by the transverse wakefield. Optical guiding of the laser pulse in the plasma is necessary in order to achieve high energies in a single stage of acceleration. At sufficiently high laser powers, optical guiding may be achieved through relativistic effects associated with the plasma electrons. Preliminary analysis indicates that this scheme may overcome some of the difficulties present in the plasma beat wave accelerator and in the plasma wakefield accelerator. Analytical and numerical calculations are presented which study both laser pulse propagation within a plasma as well as the subsequent generation of large amplitude plasma waves. In addition, the generation of large amplitude plasma waves in regimes where the plasma waves become highly nonlinear is examined

  7. Melanie Kaarma moealbum / Juta Kivimäe

    Index Scriptorium Estoniae

    Kivimäe, Juta, 1952-

    2008-01-01

    Näitus "Melanie Kaarma - 85. Tagasivaade moeloomingule" Vabaduse galeriis kuni 5. I 2009. Melanie Kaarma lõpetas 1948. a. Tallinna Riikliku Tarbekunsti Instituudi kostüümikunstnikuna, oli aastatel 1952-1957 aastaväljaannetena ilmunud "Moealbumi" kunstnik ja vastutav toimetaja

  8. Melanie Klein's metapsychology: phenomenological and mechanistic perspective.

    Science.gov (United States)

    Mackay, N

    1981-01-01

    Freud's metapsychology is the subject of an important debate. This is over whether psychoanalysis is best construed as a science of the natural science type or as a special human science. The same debate applies to Melanie Klein's work. In Klein's metapsychology are two different and incompatible models of explanation. One is taken over from Freud's structural theory and appears to be similarly mechanistic. The other is clinically based and phenomenological. These two are discussed with special reference to the concepts of "phantasy" and "internal object".

  9. Coherent multimoded dielectric wakefield accelerators

    International Nuclear Information System (INIS)

    Power, J.

    1998-01-01

    There has recently been a study of the potential uses of multimode dielectric structures for wakefield acceleration [1]. This technique is based on adjusting the wakefield modes of the structure to constructively interfere at certain delays with respect to the drive bunch, thus providing an accelerating gradient enhancement over single mode devices. In this report we examine and attempt to clarify the issues raised by this work in the light of the present state of the art in wakefield acceleration

  10. A clinical molecular scanner: the Melanie project.

    Science.gov (United States)

    Hochstrasser, D F; Appel, R D; Vargas, R; Perrier, R; Vurlod, J F; Ravier, F; Pasquali, C; Funk, M; Pellegrini, C; Muller, A F

    1991-01-01

    We developed an expert system to analyze and interpret protein maps. This system, Melanie (medical electrophoresis analysis interactive expert), can distinguish between normal and cirrhotic liver and identify various types of cancer on the basis of protein patterns in biopsy specimens. Our findings suggest that some diseases associated with toxic compounds or modifications of the human genome can be diagnosed by expert systems that analyze protein maps. The combination of protein mapping and computer analysis could result in a clinically useful "molecular scanner". The massive amount of information analyzed and stored in such studies requires new strategies, including centralized databases and image transmission over networks. Increased understanding of protein expression and regulation will enhance the importance of the human genome project in medicine and biology.

  11. Monoenergetic laser wakefield acceleration

    Directory of Open Access Journals (Sweden)

    N. E. Andreev

    2000-02-01

    Full Text Available Three dimensional test particle simulations are applied to optimization of the plasma-channeled laser wakefield accelerator (LWFA operating in a weakly nonlinear regime. Electron beam energy spread, emittance, and luminosity depend upon the proportion of the electron bunch size to the plasma wavelength. This proportion tends to improve with the laser wavelength increase. We simulate a prospective two-stage ∼1GeV LWFA with controlled energy spread and emittance. The input parameters correspond to realistic capabilities of the BNL Accelerator Test Facility that features a picosecond-terawatt CO_{2} laser and a high-brightness electron gun.

  12. Wakefield calculations on parallel computers

    International Nuclear Information System (INIS)

    Schoessow, P.

    1990-01-01

    The use of parallelism in the solution of wakefield problems is illustrated for two different computer architectures (SIMD and MIMD). Results are given for finite difference codes which have been implemented on a Connection Machine and an Alliant FX/8 and which are used to compute wakefields in dielectric loaded structures. Benchmarks on code performance are presented for both cases. 4 refs., 3 figs., 2 tabs

  13. Wakefield generation in magnetized plasmas

    International Nuclear Information System (INIS)

    Holkundkar, Amol; Brodin, Gert; Marklund, Mattias

    2011-01-01

    We consider wakefield generation in plasmas by electromagnetic pulses propagating perpendicular to a strong magnetic field, in the regime where the electron cyclotron frequency is equal to or larger than the plasma frequency. Particle-in-cell simulations reveal that for moderate magnetic field strengths previous results are reproduced, and the wakefield wave number spectrum has a clear peak at the inverse skin depth. However, when the cyclotron frequency is significantly larger than the plasma frequency, the wakefield spectrum becomes broadband, and simultaneously the loss rate of the driving pulse is much enhanced. A set of equations for the scalar and vector potentials reproducing these results are derived, using only the assumption of a weakly nonlinear interaction.

  14. Melanie Klein on mourning: Its relation to pastoral care.

    Science.gov (United States)

    Hart, C W

    1991-09-01

    This paper connects the work of Melanie Klein on mourning to the pastor's work with the grief sufferer. Klein holds that mourning is an illness of manic depressive character rooted in infantile development. Klein's description of manic defenses in the face of loss has adult behavioral analogues with which the pastor must deal to bring mourning to resolution.

  15. Argonne Wakefield Accelerator update '92

    International Nuclear Information System (INIS)

    Rosing, M.; Balka, L.; Chojnacki, E.; Gai, W.; Ho, C.; Konecny, R.; Power, J.; Schoessow, P.; Simpson, J.

    1992-01-01

    The construction of the Argonne Wakefield Accelerator (AWA) is under way. The majority of the hardware is about to be delivered or is installed. Radiation safety systems are in the review process, and the laser system is operational. Bunch production should begin in December 1992. 4 refs., 5 figs

  16. Planned Enhanced Wakefield Transformer Ratio Experiment at Argonne Wakefield Accelerator

    CERN Document Server

    Kanareykin, Alex; Gai, Wei; Jing, Chunguang; Konecny, Richard; Power, John G

    2005-01-01

    In this paper, we present a preliminary experimental study of a wakefield accelerating scheme that uses a carefully spaced and current ramped electron pulse train to produce wakefields that increases the transformer ratio much higher than 2. A dielectric structure was designed and fabricated to operate at 13.625 GHz with dielectric constant of 15.7. The structure will be initially excited by two beams with first and second beam charge ratio of 1:3. The expected transformer ratio is 3 and the setup can be easily extend to 4 pulses which leads to a transformer ratio of more than 6. The dielectric structure cold test results show the tube is within the specification. A set of laser splitters was also tested to produce ramped bunch train of 2 - 4 pulses. Overall design of the experiment and initial results will be presented.

  17. Adrian Stokes and the portrait of Melanie Klein.

    Science.gov (United States)

    Sayers, Janet

    2015-08-01

    This paper focuses on the offer by the art writer Adrian Stokes to commission and pay for a portrait of the psychoanalyst Melanie Klein by the artist William Coldstream. It details some of the precursors of this offer in Stokes's preceding involvement first with Klein and then with Coldstream; her response to this offer; and its outcome and aftermath in Stokes's subsequent writing about Klein and Coldstream. Copyright © 2015 Institute of Psychoanalysis.

  18. Argonne's new Wakefield Test Facility

    International Nuclear Information System (INIS)

    Simpson, J.D.

    1992-01-01

    The first phase of a high current, short bunch length electron beam research facility, the AWA, is near completion at Argonne. At the heart of the facility is a photocathode based electron gun and accelerating sections designed to deliver 20 MeV pulses with up to 100 nC per pulse and with pulse lengths of approximately 15 ps (fw). Using a technique similar to that originated at Argonne's AATF facility, a separate weak probe pulse can be generated and used to diagnose wake effects produced by the intense pulses. Initial planned experiments include studies of plasma wakefields and dielectric wakefield devices, and expect to demonstrate large, useful accelerating gradients (> 100 MeV/m). Later phases of the facility will increase the drive bunch energy to more than 100 MeV to enable acceleration experiments up to the GeV range. Specifications, design details, and commissioning progress are presented

  19. A proposed laser wakefield acceleration experiment

    International Nuclear Information System (INIS)

    Ebrahim, N.A.

    1995-05-01

    In this report we discuss the basic concepts of a laser wakefield experiment using an ultrashort laser pulse. In particular, we obtain some heuristic estimates of experimental parameters relevant to an experiment to test the laser wakefield acceleration concept. (author). 8 refs., 2 tabs

  20. The nonlinear CWFA [Cherenkov Wakefield Accelerator

    International Nuclear Information System (INIS)

    Schoessow, P.

    1989-01-01

    The possible use of nonlinear media to enhance the performance of the Cherenkov Wakefield Accelerator (CWFA) is considered. Numerical experiments have been performed using a new wakefield code which demonstrate larger gradients and transformer ratios in the nonlinear CWFA than are obtained in the linear case. 7 refs., 3 figs

  1. Transition from wakefield generation to soliton formation

    Science.gov (United States)

    Holkundkar, Amol R.; Brodin, Gert

    2018-04-01

    It is well known that when a short laser pulse propagates in an underdense plasma, it induces longitudinal plasma oscillations at the plasma frequency after the pulse, typically referred to as the wakefield. However, for plasma densities approaching the critical density, wakefield generation is suppressed, and instead the EM-pulse (electromagnetic pulse) undergoes nonlinear self-modulation. In this article we have studied the transition from the wakefield generation to formation of quasi-solitons as the plasma density is increased. For this purpose we have applied a one-dimensional relativistic cold fluid model, which has also been compared with particle-in-cell simulations. A key result is that the energy loss of the EM-pulse due to wakefield generation has its maximum for a plasma density of the order 10% of the critical density, but that wakefield generation is sharply suppressed when the density is increased further.

  2. Melanie Klein and countertransference: a note on some archival material.

    Science.gov (United States)

    Hinshelwood, R D

    2008-01-01

    Five pages of notes were found in the Melanie Klein Archives at the Wellcome Library that concern her views on countertransference in 1953. Because of the paucity of references to countertransference in Klein's published writings these Notes fill in out knowledge. Her views were provoked by the work her students were doing in their experimental analyses of schizophrenic patients. Apocryphal stories suggest that Klein remained aligned with Freud's view of countertransference as simply interference. The Notes confirm that, whilst there is some truth to that, she did have a more sophisticated and nuanced view of the unconscious relations between analyst and analysand.

  3. [An unpublished contribution of Melanie Klein "On Reassurance"].

    Science.gov (United States)

    Frank, Claudia; Klein, Melanie

    2005-01-01

    Melanie Klein's unpublished paper on reassurance is presented in German translation. The author shows that it was a contribution to Glover's investigation on psychoanalytic technique in the 1930s. The paper is discussed against the background of the technical discussions conducted in London at that time (e. g. M. Schmideberg, J. Strachey) and of Klein's relevant publications. Although Klein consistently considered "correct" interpretation to be the most effective means of reassurance, she occasionally also accepted a non-interpreting approach. In this respect the paper presented here goes further than any other of her writings.

  4. Wakefield effects in a linear collider

    International Nuclear Information System (INIS)

    Bane, K.L.F.

    1986-12-01

    In this paper the wakefields for the Stanford Linear Accelerator Center (SLAC) accelerating structure are first discussed, and then some considerations dealing with the longitudinal wakefields are described. The main focus is on the effects of the transverse wakefield on the beam, including the case when there is an energy variation along the bunch. The use of an energy spread to inhibit emittance growth in a linac, indeed to damp the oscillations of the core of the bunch to below the unperturbed betatron oscillations, (in a process that is similar to Landau Damping) is qualitatively detailed. The example of the SLC, including errors, is also in detail

  5. Melanie Klein's letters addressed to Marcelle Spira (1955-1960).

    Science.gov (United States)

    Quinodoz, Jean-Michel

    2009-12-01

    Between 1955 and 1960, Melanie Klein wrote some 45 hitherto unpublished letters to Marcelle Spira, the Swiss psychoanalyst living at that time in Geneva. In 2006, after Spira's death, these letters were deposited with the Raymond de Saussure Psychoanalysis Centre in Geneva. They are the only known letters that Klein addressed to her psychoanalyst colleagues. Several topics are mentioned in them: (1) the meetings between the two women in Geneva and London; (2) Spira's contribution to Boulanger's translation into French of The Psychoanalysis of Children, which Klein herself carefully revised; (3) the papers that Klein was at that time working on, including Envy and Gratitude; (4) Spira's own work; (5) the difficulties that Spira, a Kleinian psychoanalyst who trained in Buenos Aires, was encountering in her attempt to be admitted to the Swiss Psychoanalytical Society; and (6) a few items of personal and family news. In addition to the invaluable historical information that these letters provide, they offer us a very moving epistolary self-portrait of Melanie Klein, enabling us to discover her personality in the final years of her life - she died in September 1960, just two months after writing her last letter to Spira.

  6. Wakefield effects in the SLC beam delivery system

    International Nuclear Information System (INIS)

    Napoly, O.

    1996-06-01

    Wakefield effects occurring in the SLC after the LI28 emittance measurement station could be responsible for part of all of the observed discrepancy between the expected vertical spot sizes at the IP and the measured ones. The strongest wakefields are generated by the parts of the beam chamber which are the closest to the beam, like collimators. In this note we review the effect of the following wakefield sources: geometric wakefields from final focus fixed and movable collimators, geometric and resistive wakefields from linac collimators jaws, resistive wakefields from the beam pipe at the sextupole and final transformer locations. We mostly concentrate on the transverse dipole and quadrupole wakefield effects, although the longitudinal wakefields are briefly studied at the end. We limit ourselves to the vertical beam dynamics and to the lowest (mainly linear) order of the wakefield expansion with respect to the beam offset, which excludes the near wall effect on the beam. (author)

  7. Minimum wakefield achievable by waveguide damped cavity

    International Nuclear Information System (INIS)

    Lin, X.E.; Kroll, N.M.

    1995-01-01

    The authors use an equivalent circuit to model a waveguide damped cavity. Both exponentially damped and persistent (decay t -3/2 ) components of the wakefield are derived from this model. The result shows that for a cavity with resonant frequency a fixed interval above waveguide cutoff, the persistent wakefield amplitude is inversely proportional to the external Q value of the damped mode. The competition of the two terms results in an optimal Q value, which gives a minimum wakefield as a function of the distance behind the source particle. The minimum wakefield increases when the resonant frequency approaches the waveguide cutoff. The results agree very well with computer simulation on a real cavity-waveguide system

  8. Proton-driven Plasma Wakefield Acceleration

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The construction of ever larger and costlier accelerator facilities has a limited future, and new technologies will be needed to push the energy frontier. Plasma wakefield acceleration is a rapidly developing field and is a promising candidate technology for future high energy colliders. We focus on the recently proposed idea of proton-driven plasma wakefield acceleration and describe the current status and plans for this approach.

  9. The conflict and process theory of Melanie Klein.

    Science.gov (United States)

    Kavaler-Adler, S

    1993-09-01

    This article depicts the theory of Melanie Klein in both its conflict and process dimensions. In addition, it outlines Klein's strategic place in psychoanalytic history and in psychoanalytic theory formation. Her major contributions are seen in light of their clinical imperatives, and aspects of her metapsychology that seem negligible are differentiated from these clinical imperatives. Klein's role as a dialectical fulcrum between drive and object relations theories is explicated. Within the conflict theory, drive derivatives of sex and aggression are reformulated as object-related passions of love and hate. The process dimensions of Klein's theory are outlined in terms of dialectical increments of depressive position process as it alternates with regressive paranoid-schizoid-position mental phenomenology. The mourning process as a developmental process is particularly high-lighted in terms of self-integrative progression within the working through of the depressive position.

  10. A new look at the theory of Melanie Klein.

    Science.gov (United States)

    Stein, R

    1990-01-01

    This paper tried to show that Melanie Klein's theory can very profitably be viewed as a descriptive theory of strong emotions rather than an instinct or developmental theory. Furthermore, since in Klein's thinking feelings 'create' objects, the primacy of feelings in this theory is central. The paper contains a short chronological study of Klein's formulations of psychic phenomena in terms of affects. It is also maintained that the paranoid-schizoid and the depressive positions are constellations of affects and of reactions to them; that psychic development is essentially in terms of the capacity to tolerate feelings, and that the basic conflict in mental life is between feelings of love and hate and associated feelings. Such a view solves many of the conceptual difficulties of Kleinian theory and in addition promises rewarding insights into the world of feelings.

  11. Wakefield Band Partitioning in LINAC Structures

    International Nuclear Information System (INIS)

    Jones, Roger M

    2003-01-01

    In the NLC project multiple bunches of electrons and positrons will be accelerated initially to a centre of mass of 500 GeV and later to 1 TeV or more. In the process of accelerating 192 bunches within a pulse train, wakefields are excited which kick the trailing bunches off axis and can cause luminosity dilution and BBU (Beam Break Up). Several structures to damp the wakefield have been designed and tested at SLAC and KEK and these have been found to successfully damp the wakefield [1]. However, these 2π/3 structures suffered from electrical breakdown and this has prompted us to explore lower group velocity structures operating at higher fundamental mode phase advances. The wakefield partitioning amongst the bands has been found to change markedly with increased phase advance. Here we report on general trends in the kick factor and associated wakefield band partitioning in dipole bands as a function of phase advance of the synchronous mode in linacs. These results are applicable to both TW (travelling wave) and SW (standing wave) structures

  12. Some developments from the work of Melanie Klein.

    Science.gov (United States)

    Spillius, E B

    1983-01-01

    This paper discusses four areas of work in which several followers of Melanie Klein in Britain have developed some of the discoveries and ideas she initiated. First, extension of her concept of projective identification is briefly described, with emphasis on Bion's and Rosenfeld's stress on its communicative as well as its pathological aspects. Second, the extension of Klein's ideas about the epistemophilic instinct, on symbolism, and about projective identification is described in the work of Segal, Bion, Money-Kyrle, and Bick on the development of the capacity to think. Third, certain developments in Kleinian technique are described, with emphasis on the use of the concept of projective identification in analysing transference, and on the analysis of acting out in the transference, a trend contributed to by many Kleinian analysts but perhaps most closely associated with Betty Joseph. Finally, continued refinements in the analysis of the death instinct are briefly described, together with discussion of the changes these refinements have led to in ideas about the organization and relations of parts of the self and internal objects.

  13. Primitive object love in Melanie Klein's thinking; early theoretical influences.

    Science.gov (United States)

    Likierman, M

    1993-04-01

    Melanie Klein's thinking on early object love is pivotal to her vision of development. Yet within her texts it is often enmeshed in complex formulations that obscure its full significance. A greater clarity in viewing Klein's concept of early object love is achieved through tracing some of its historical origins. The author notes that it was inspired by aspects of Ferenczi's theory, hence its similarities with the concept of 'primary love' formulated by another of Ferenczi's analysands, Michael Balint. Ferenczi's thinking on the subject formed part of a broader network of theoretical developments in the history of psychoanalytic ideas. These are shown to have origins in Freud's fluctuations between a 'passive' and a 'genital' characterisation of infantile sexuality. A dialectical tension between these two possibilities, as maintained in the Freudian texts, was partly embodied in the differing outlooks of Klein's two psychoanalysts, Abraham and Ferenczi. The author suggests that it is a mixture of their approaches that partly shaped Klein's thinking on the earliest experiences of love. After outlining these developments the author analyses the nature of early object love as it emerges from Klein's powerful, if intermittent descriptions in the texts. The analysis also tackles a textual ambiguity in Klein's formulations, showing that she explored two kinds of primitive ideal experience without explicitly differentiating them. Such differentiation is important inasmuch as it highlights negative and positive aspects of Kleinian theory at root.

  14. Electromagnetic radiation from a laser wakefield accelerator

    NARCIS (Netherlands)

    Khachatryan, A.G.; van Goor, F.A.; Boller, Klaus J.

    2008-01-01

    Coherent and incoherent electromagnetic radiation emitted from a laser wakefield accelerator is calculated based on Lienard-Wiechert potentials. It is found that at wavelengths longer than the bunch length, the radiation is coherent. The coherent radiation, which typically lies in the infrared

  15. Laser wakefields at UCLA and LLNL

    International Nuclear Information System (INIS)

    Mori, W.B.; Clayton, C.E.; Joshi, C.; Dawson, J.M.; Decker, C.B.; Marsh, K.; Katsouleas, T.; Darrow, C.B.; Wilks, S.C.

    1991-01-01

    The authors report on recent progress at UCLA and LLNL on the nonlinear laser wakefield scheme. They find advantages to operating in the limit where the laser pulse is narrow enough to expel all the plasma electrons from the focal region. A description of the experimental program for the new short pulse 10 TW laser facility at LLNL is also presented

  16. Towards external injection in laser wakefield acceleration

    NARCIS (Netherlands)

    Stragier, X.F.D.

    2011-01-01

    In laser wakefield acceleration (LWA) a plasma wave is driven by a high intensity ultra short laser pulse and the longitudinal electric fields in the plasma wave are used to accelerate electron bunches. Electrons with an appropriate kinetic energy, injected on the right phase of the plasma wave, get

  17. Discovering "The Italian Flag" by Fernando Melani (1907-1985).

    Science.gov (United States)

    Carlesi, Serena; Bartolozzi, Giovanni; Cucci, Costanza; Marchiafava, Veronica; Picollo, Marcello; La Nasa, Jacopo; Di Girolamo, Francesca; Dilillo, Marialaura; Modugno, Francesca; Degano, Ilaria; Colombini, Maria Perla; Legnaioli, Stefano; Lorenzetti, Giulia; Palleschi, Vincenzo

    2016-11-05

    In the occasion of the celebrations for the 150th anniversary of the founding of Italy (1861-2011), it was decided to analyse the artwork "The Italian Flag" (La Bandiera Italiana) created by the artist Fernando Melani (Pistoia, 1907-1985), one of the precursors of the Poor Art artistic movement in Italy. This project is a follow-up to a previous study which was mainly focused on the pigments and dyes found in his home-studio. The main goal of this paper is to identify a correct diagnostic plan, based on the use of a combination of non-invasive and micro-invasive methodologies, in order to determine the state of preservation and define the best conservation procedures for a contemporary artwork. Visible, infrared and infrared false colour images as well as the Fibre Optic Reflectance Spectroscopy (FORS) technique were applied in situ to analyse The Italian Flag. Laser Induced Breakdown Spectroscopy (LIBS), Fourier Transform Infrared (FT-IR) and micro-Raman spectroscopies, Pyrolysis-Gas Chromatography/Mass Spectroscopy (Py-GC/MS), High Performance Liquid Chromatography with Diode Arrays Detection (HPLC-DAD) and Mass Spectrometric Detection (HPLC-ESI-Q-ToF) were all applied to three small samples detached from the three painted (green-blue, white and red-yellow, respectively) areas of the flag. The combination of the data obtained with all these techniques made possible a comprehensive understanding of both the chemical composition and physical behaviour of the materials used by the artist and supported curators in defining the preventive conservation of this artwork. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Discovering "The Italian Flag" by Fernando Melani (1907-1985)

    Science.gov (United States)

    Carlesi, Serena; Bartolozzi, Giovanni; Cucci, Costanza; Marchiafava, Veronica; Picollo, Marcello; La Nasa, Jacopo; Di Girolamo, Francesca; Dilillo, Marialaura; Modugno, Francesca; Degano, Ilaria; Colombini, Maria Perla; Legnaioli, Stefano; Lorenzetti, Giulia; Palleschi, Vincenzo

    2016-11-01

    In the occasion of the celebrations for the 150th anniversary of the founding of Italy (1861-2011), it was decided to analyse the artwork ;The Italian Flag; (La Bandiera Italiana) created by the artist Fernando Melani (Pistoia, 1907-1985), one of the precursors of the Poor Art artistic movement in Italy. This project is a follow-up to a previous study which was mainly focused on the pigments and dyes found in his home-studio. The main goal of this paper is to identify a correct diagnostic plan, based on the use of a combination of non-invasive and micro-invasive methodologies, in order to determine the state of preservation and define the best conservation procedures for a contemporary artwork. Visible, infrared and infrared false colour images as well as the Fibre Optic Reflectance Spectroscopy (FORS) technique were applied in situ to analyse The Italian Flag. Laser Induced Breakdown Spectroscopy (LIBS), Fourier Transform Infrared (FT-IR) and micro-Raman spectroscopies, Pyrolysis-Gas Chromatography/Mass Spectroscopy (Py-GC/MS), High Performance Liquid Chromatography with Diode Arrays Detection (HPLC-DAD) and Mass Spectrometric Detection (HPLC-ESI-Q-ToF) were all applied to three small samples detached from the three painted (green-blue, white and red-yellow, respectively) areas of the flag. The combination of the data obtained with all these techniques made possible a comprehensive understanding of both the chemical composition and physical behaviour of the materials used by the artist and supported curators in defining the preventive conservation of this artwork.

  19. Quantitative single shot and spatially resolved plasma wakefield diagnostics

    CERN Document Server

    Kasim, Muhammad Firmansyah; Ceurvorst, Luke; Levy, Matthew C; Ratan, Naren; Sadler, James; Bingham, Robert; Burrows, Philip N; Trines, Raoul; Wing, Matthew; Norreys, Peter

    2015-01-01

    Diagnosing plasma conditions can give great advantages in optimizing plasma wakefield accelerator experiments. One possible method is that of photon acceleration. By propagating a laser probe pulse through a plasma wakefield and extracting the imposed frequency modulation, one can obtain an image of the density modulation of the wakefield. In order to diagnose the wakefield parameters at a chosen point in the plasma, the probe pulse crosses the plasma at oblique angles relative to the wakefield. In this paper, mathematical expressions relating the frequency modulation of the laser pulse and the wakefield density profile of the plasma for oblique crossing angles are derived. Multidimensional particle-in-cell simulation results presented in this paper confirm that the frequency modulation profiles and the density modulation profiles agree to within 10%. Limitations to the accuracy of the measurement are discussed in this paper. This technique opens new possibilities to quantitatively diagnose the plasma wakefie...

  20. Melanie Klein, una princesa que creó su propio reino

    OpenAIRE

    Sánchez-Barranco Ruiz, Antonio; Vallejo Orellana, Reyes

    2004-01-01

    Las formulaciones kleinianas no pueden ser encuadradas como un mero desarrollo del psicoanálisis freudiano, dado que suponen cambios radicales en su metapsicología, núcleo intocable del sistema. En todo caso, Melanie Klein merece un lugar de privilegio entre las mujeres pioneras que aportaron ideas originales a la psicología del inconsciente y aunque siempre se autoconsideró una fiel seguidora de Freud, terminó desarrollando su propio reino. Melanie Klein's formulations should not be frame...

  1. Melanie Klein, una princesa que creó su propio reino

    OpenAIRE

    Vallejo Orellana, Reyes; Sánchez-Barranco Ruiz, Antonio

    2004-01-01

    Las formulaciones kleinianas no pueden ser encuadradas como un mero desarrollo del psicoanálisis freudiano, dado que suponen cambios radicales en su metapsicología, núcleo intocable del sistema. En todo caso, Melanie Klein merece un lugar de privilegio entre las mujeres pioneras que aportaron ideas originales a la psicología del inconsciente y aunque siempre se autoconsideró una fiel seguidora de Freud, terminó desarrollando su propio reino. Melanie Klein’s formulations should not be frame...

  2. High energy photon emission from wakefields

    Energy Technology Data Exchange (ETDEWEB)

    Farinella, D. M., E-mail: dfarinel@uci.edu; Lau, C. K.; Taimourzadeh, S.; Hwang, Y.; Abazajian, K.; Canac, N.; Taborek, P.; Tajima, T. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Zhang, X. M., E-mail: zhxm@siom.ac.cn [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Koga, J. K., E-mail: koga.james@qst.go.jp [Kansai Photon Science Institute, Japan Atomic Energy Agency (JAEA), Kizugawa, Kyoto 619-0215 (Japan); Ebisuzaki, T., E-mail: ebisu@riken.jp [RIKEN, Wako, Saitama 351-0198 (Japan)

    2016-07-15

    Experimental evidence has accumulated to indicate that wakefield acceleration (WFA) accompanies intense and sometimes coherent emission of radiation such as from betatron radiation. The investigation of this issue has additional impetus nowadays because we are learning (1) there is an additional acceleration process of the ponderomotive acceleration; (2) WFA may become relevant in much higher density regimes; (3) WFA has been proposed as the mechanism for extreme high energy cosmic ray acceleration and gamma ray bursts for active galactic nuclei. These require us to closely examine the radiative mechanisms in WFA anew. We report studies of radiation from wakefield (self-injected betatron) and ponderomotive (laser field) mechanisms in scalings of the frequency and intensity of the driver, as well as the plasma density.

  3. Wakefields and Instabilities in Linear Accelerators

    CERN Document Server

    Ferrario, M.; Palumbo, L.

    2014-12-19

    When a charged particle travels across the vacuum chamber of an accelerator, it induces electromagnetic fields, which are left mainly behind the generating particle. These electromagnetic fields act back on the beam and influence its motion. Such an interaction of the beam with its surro undings results in beam energy losses, alters the shape of the bunches, and shifts the betatron and synchrotron frequencies. At high beam current the fields can even lead to instabilities, thus limiting the performance of the accelerator in terms of beam quality and current intensity. We discuss in this lecture the general features of the electromagnetic fields, introducing the concepts of wakefields and giving a few simple examples in cylindrical geometry. We then show the effect of the wakefields on the dynamics of a beam in a linac, dealing in particular with the beam breakup instability and how to cure it.

  4. Short-range wakefields generated in the blowout regime of plasma-wakefield acceleration

    Science.gov (United States)

    Stupakov, G.

    2018-04-01

    In the past, calculation of wakefields generated by an electron bunch propagating in a plasma has been carried out in linear approximation, where the plasma perturbation can be assumed small and plasma equations of motion linearized. This approximation breaks down in the blowout regime where a high-density electron driver expels plasma electrons from its path and creates a cavity void of electrons in its wake. In this paper, we develop a technique that allows us to calculate short-range longitudinal and transverse wakes generated by a witness bunch being accelerated inside the cavity. Our results can be used for studies of the beam loading and the hosing instability of the witness bunch in plasma-wakefield and laser-wakefield acceleration.

  5. Photon acceleration in laser wakefield accelerators

    International Nuclear Information System (INIS)

    Trines, R. M. G. M.

    2007-01-01

    If the index of a refraction of a dispersive medium, such as a plasma, changes in time, it can be used to change the frequency of light propagating through the medium. This effect is called photon acceleration. It has been predicted in both theory and simulations, and also been demonstrated experimentally for the case of moving ionization fronts in gases (the so-called ionization blueshift) as well as for laser-driven wakefields.Here, we present studies of photon acceleration in laser-driven plasma wakefields. The unique spectral characteristics of this process will be discussed, to distinguish it from e.g. photon acceleration by ionization fronts, frequency domain interferometry or self-phase modulation. The dynamics of the photons in laser-wakefield interaction are studied through both regular particle-in-cell and wave-kinetic simulations. The latter approach provides a powerful, versatile, and easy-to-use method to track the propagation of individual spectral components, providing new insight into the physics of laser-plasma interaction. Theory, simulations and experimental results will be brought together to provide a full understanding of the dynamics of a laser pulse in its own wakefield.Even though the wave-kinetic approach mentioned above has mainly been developed for the description of laser-plasma interaction, it can be applied to a much wider range of fast wave-slow wave interaction processes: Langmuir waves-ion acoustic waves, drift waves-zonal flow, Rossby waves-zonal flow, or even photons-gravitational waves. Several recent results in these areas will be shown, often with surprising results

  6. Comments on 'the case of Melanie' and the reaction of Eduardo Gastelumendi.

    Science.gov (United States)

    Kast, Verena

    2011-06-01

    Following an attempt to connect the theory of archetypes with the theory of primal phantasies, the commentary refers to how moments of complexity may be differentiated in terms of 'now moments' and concludes with an amplification of the 'black woman' in Melanie's dream related to a black woman in an important Austrian fairy tale. © 2011, The Society of Analytical Psychology.

  7. From Peripheral to Central, the Story of Melanie's Metamorphosis in an Urban Middle School Science Class

    Science.gov (United States)

    Tan, Edna; Barton, Angela Calabrese

    2008-01-01

    Identity formation is a critical dimension of how and why students engage in science to varying degrees. In this paper, we use the lens of identity formation, and in particular identities in practice, to make sense of how and why Melanie, over the course of sixth grade, transformed from a marginalized member of the science class with a failing…

  8. Transverse wakefield effects in the two-beam accelerator

    International Nuclear Information System (INIS)

    Selph, F.; Sessler, A.

    1986-01-01

    Transverse wakefield effects in the high-gradient accelerating structure of the two-beam accelerator (TBA) are analyzed theoretically using three different models. The first is a very simple two-particle model, the second is for a beam with uniform charge distribution, constant betatron wavelength, and a linear wake approximation. Both of these models give analytic scaling laws. The third model has a Gaussian beam (represented by 11 superparticles), energy variation across the bunch, acceleration, variation of betatron focusing with energy, and variation of the wakefield from linearity. The three models are compared, and the third model is used to explore the wakefield effects when accelerator parameters such as energy, energy spread, injection energy, accelerating gradient, and betatron wavelength are varied. Also explored are the sensitivity of the beam to the wakefield profile to the longitudinal charge distribution. Finally, in consideration of wakefield effects, possible parameters of a TBA are presented. (orig./HSI)

  9. The transverse forces in wakefield accelerators

    International Nuclear Information System (INIS)

    Rosing, M.; Gai, W.

    1990-01-01

    An attempt is presented to compare beam breakup problems in dielectric lined waveguide with plasmas as they pertain to wakefield accelerators. In the waveguide position it is measured relative to the physical center of the guide but in a plasma position it is relative to the centroid of the bunch creating the wakes. Dielectrics are very linear making their behaviour well suited for analytical study. Plasmas are very nonlinear so many approximations should be made to put them into an analytical regime. (R.P.) 6 refs.; 4 figs

  10. Theory of the dielectric wakefield accelerator

    International Nuclear Information System (INIS)

    Mtingwa, S.K.

    1990-10-01

    The general theory for all angular modes m of the dielectric wakefield accelerator is reformulated. The expressions for the accelerating electric fields and transverse wake forces are written in terms of matrices, the zeros of one of which determine the excitation frequencies of the dielectric structure. In this scheme it is possible to obtain a maximum accelerating gradient of 2.0 megavolts per meter per nanoCoulomb of driver beam charge, for a driver beam of 0.7 millimeters rms bunch length. 29 refs., 5 figs

  11. Laser surface wakefield in a plasma column

    International Nuclear Information System (INIS)

    Gorbunov, L.M.; Mora, P.; Ramazashvili, R.R.

    2003-01-01

    The structure of the wakefield in a plasma column, produced by a short intense laser pulse, propagating through a gas affected by tunneling ionization is investigated. It is shown that besides the usual plasma waves in the bulk part of the plasma column [see Andreev et al., Phys. Plasmas 9, 3999 (2002)], the laser pulse also generates electromagnetic surface waves propagating along the column boundary. The length of the surface wake wave substantially exceeds the length of the plasma wake wave and its electromagnetic field extends far outside the plasma column

  12. Laser wakefield accelerator experiments at LBNL

    International Nuclear Information System (INIS)

    Leemans, W.P.; Rodgers, D.; Catravas, P.E.; Fubiani, G.; Geddes, C.G.R.; Esarey, E.; Shadwick, B.A.; Brussaard, G.J.H.; Tilborg, J. van; Chattopadhyay, S.; Wurtele, J.S.; Archambault, L.; Dickinson, M.R.; DiMaggio, S.; Short, R.; Barat, K.L.; Donahue, R.; Floyd, J.; Smith, A.; Wong, E.

    2001-01-01

    The status is presented of the laser wakefield acceleration research at the l'OASIS laboratory of the Center for Beam Physics at LBNL. Experiments have been performed on laser driven production of relativistic electron beams from plasmas using a high repetition rate (10 Hz), high power (10 TW) Ti:sapphire (0.8 μm) laser system. Large amplitude plasma waves have been excited in the self-modulated laser wakefield regime by tightly focusing (spot diameter 8 μm) a single high power (≤10 TW), ultra-short (≥50 fs) laser pulse onto a high density (>10 19 cm -3 ) pulsed gasjet (length 1.2 mm). Nuclear activation measurements in lead and copper targets indicate the production of electrons with energy in excess of 25 MeV. This result was confirmed by electron distribution measurements using a bending magnet spectrometer. Progress on implementing the colliding pulse laser injection method is also presented. This method is expected to produce low emittance ( 7 electrons/bunch

  13. Melanie Klein and Anna Freud: the discourse of the early dispute.

    Science.gov (United States)

    Viner, R

    1996-01-01

    Divisions in the field of the psychoanalysis of children can be traced to a dispute over the infantile super-ego between the theorists Melanie Klein and Anna Freud beginning in 1927. These divisions are understood within the analytic world as the result of scientific disputation between alternative valid theories. An examination of the language, claims, and epistemology of Klein's and Freud's publications in 1927 that marked the public commencement of the conflict, reveals a personalized discourse in which authority was derived from the allegiance, experience, and personal analytic standing of the contestants as much as from theoretical insight. The structure and rhetoric of the debate suggest that, rather than terminating the dispute, the publications of 1927 served to encourage professionalization in child analysis and establish Anna Freud and Melanie Klein as authoritative alternative theorists.

  14. THE PSYCHOANALYTIC CONTRIBUTIONS OF MELITTA SCHMIDEBERG KLEIN. MORE THAN MELANIE KLEIN'S REBEL DAUGHTER.

    Science.gov (United States)

    Cassullo, Gabriele

    2016-03-01

    Compared to the impact of the work of Melanie Klein on the history of psychoanalysis, the contributions of her daughter, Melitta Schmideberg, passed almost unnoticed. At present, Schmideberg is solely remembered for having harshly attacked her mother at the start of the Controversial Discussions of the British Psycho-Analytical Society and for having coined the fitting expression "stable instability" in order to describe borderline and asocial personality disorders. However, the author discusses how the early groundbreaking discoveries of Klein with regards to primitive anxieties were the result of the joint work and thinking of Melanie and Melitta. Moreover, he argues that the conflict between the two, along with the subsequent polarization of their views, did not facilitate the development of psychoanalysis, neither did it help the analytic community to recognize the value of Melitta's contributions to psychoanalysis.

  15. Theories on anxiety in Freud and Melanie Klein. Their metapsychological status.

    Science.gov (United States)

    De Bianchedi, E T; Scalozub De Boschan, L; De Cortiñas, L P; De Piccolo, E G

    1988-01-01

    This paper presents a comparative study of the theories on anxiety formulated by Freud and Melanie Klein, with particular emphasis on the questions of its origin, its meaning for the individual and its function in both theoretical systems. The purpose of this comparative analysis is to offer an instrument which helps frame the theoretical discussions in psychoanalysis in an epistemological context. The authors hold that for Freud anxiety is considered as one more amongst the various manifestations of mental life, which his general theories try to explain, whereas for Melanie Klein anxiety and its destinies occupies a central place in her theories on mental functioning. The differences in both theories, which the authors of this paper describe, especially as to origin, function and meaning of anxiety, respond partially to the different metapsychological points of view with which both authors focus mental life--points of view which they have themselves investigated in a previous paper.

  16. The MELANIE project: from a biopsy to automatic protein map interpretation by computer.

    Science.gov (United States)

    Appel, R D; Hochstrasser, D F; Funk, M; Vargas, J R; Pellegrini, C; Muller, A F; Scherrer, J R

    1991-10-01

    The goals of the MELANIE project are to determine if disease-associated patterns can be detected in high resolution two-dimensional polyacrylamide gel electrophoresis (HR 2D-PAGE) images and if a diagnosis can be established automatically by computer. The ELSIE/MELANIE system is a set of computer programs which automatically detect, quantify, and compare protein spots shown on HR 2D-PAGE images. Classification programs help the physician to find disease-associated patterns from a given set of two-dimensional gel electrophoresis images and to form diagnostic rules. Prototype expert systems that use these rules to establish a diagnosis from new HR 2D-PAGE images have been developed. They successfully diagnosed cirrhosis of the liver and were able to distinguish a variety of cancer types from biopsies known to be cancerous.

  17. The artists' materials of Fernando Melani: A precursor of the Poor Art artistic movement in Italy

    Science.gov (United States)

    Carlesi, Serena; Bartolozzi, Giovanni; Cucci, Costanza; Marchiafava, Veronica; Picollo, Marcello

    2013-03-01

    A comprehensive understanding of both the chemical composition and physical behaviour of modern materials is an important consideration in devising correct conservation treatments for contemporary artworks. To this end, national and international research projects and networks have been established that deal mainly with the preservation, conservation, and understanding of materials used by contemporary artists. This paper focuses on the self-taught artist Fernando Melani (1907-1985), one of the precursors of the Poor Art artistic movement in Italy, and for the first time provides a scientific viewpoint on the artist's materials and works. The analyses, which mainly focus on the pigments/dyes found in his home-studio, were carried out primarily by using Fourier Transform Infrared Spectroscopy (FT-IR) and ultraviolet, visible, and near-infrared Fibre Optic Reflectance Spectroscopy (UV-Vis-NIR FORS). This paper emphasises the performance of FT-IR and FORS in the identification of contemporary artistic materials, since these two techniques have been found to produce highly complementary data. The use of both of these was required in order to obtain a comprehensive understanding of the composition of Melani's materials. Furthermore, one of his artworks, named by Melani himself with its inventory number N. Inv. 2625 (1981), was investigated in situ with the sole use of the FORS technique. The results showed that Melani used traditional inorganic pigments as well as modern organic dyes. Calcite and barite were used as fillers and extenders. Sulphur and abrasive powder were also found, thus confirming his use of a large variety of non-conventional artists' materials.

  18. The artists' materials of Fernando Melani: a precursor of the Poor Art artistic movement in Italy.

    Science.gov (United States)

    Carlesi, Serena; Bartolozzi, Giovanni; Cucci, Costanza; Marchiafava, Veronica; Picollo, Marcello

    2013-03-01

    A comprehensive understanding of both the chemical composition and physical behaviour of modern materials is an important consideration in devising correct conservation treatments for contemporary artworks. To this end, national and international research projects and networks have been established that deal mainly with the preservation, conservation, and understanding of materials used by contemporary artists. This paper focuses on the self-taught artist Fernando Melani (1907-1985), one of the precursors of the Poor Art artistic movement in Italy, and for the first time provides a scientific viewpoint on the artist's materials and works. The analyses, which mainly focus on the pigments/dyes found in his home-studio, were carried out primarily by using Fourier Transform Infrared Spectroscopy (FT-IR) and ultraviolet, visible, and near-infrared Fibre Optic Reflectance Spectroscopy (UV-Vis-NIR FORS). This paper emphasises the performance of FT-IR and FORS in the identification of contemporary artistic materials, since these two techniques have been found to produce highly complementary data. The use of both of these was required in order to obtain a comprehensive understanding of the composition of Melani's materials. Furthermore, one of his artworks, named by Melani himself with its inventory number N. Inv. 2625 (1981), was investigated in situ with the sole use of the FORS technique. The results showed that Melani used traditional inorganic pigments as well as modern organic dyes. Calcite and barite were used as fillers and extenders. Sulphur and abrasive powder were also found, thus confirming his use of a large variety of non-conventional artists' materials. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. The life and work of Melanie Klein in the British Psycho-Analytical Society.

    Science.gov (United States)

    King, P H

    1983-01-01

    This paper describes certain aspects of the life and work of Melanie Klein in the British Psycho-Analytical Society. It attempts to highlight the reciprocity of the relationship between Melanie Klein and other members of that Society by showing how the climate of psychoanalytical opinion that was prevalent among members of that Society during the first decade of her stay in London, and which encouraged discussion of clinical work and interest in psychoanalytical discovery, provided a congenial setting for her to become firmly established as an active member of the British Society and to continue her contributions to psychoanalytic theory and clinical expertise. The paper also traces the development of Melanie Klein's main theoretical contributions, together with relevant criticisms of them as they emerged, against the background of the history of the British Psycho-Analytical Society. It describes the controversies that arose as to whether or not her ideas could properly be viewed within the framework of psychoanalytic theory, as formulated by Freud, and the attempted resolution of these controversies, together with some comments on the repercussions of these theoretical disagreements on relationships within the Society. An extensive list of references is included to facilitate a more detailed study of the subject.

  20. A neurose obsessiva sob a ótica de Melanie Klein

    Directory of Open Access Journals (Sweden)

    Marcos Leandro Klipan

    2012-12-01

    Full Text Available Essa pesquisa aborda o tema 'neurose obsessiva' na obra de Melanie Klein. Assim, foi possível estudar um panorama histórico da construção do pensamento dessa autora - tendo em vista que seguimos um itinerário cronológico de seus textos - e, como consequência importante, obter uma dimensão epistemológica dessa construção. Isso porque a neurose obsessiva constitui-se como um destacado elemento organizador da obra de Klein, sobretudo nas décadas de 1920 e 1930, período que marcou o atendimento dos primeiros pacientes da autora que, em sua maioria, eram crianças que sofriam de neurose obsessiva.The obsessive neurosis from Melanie Klein's optic. This research focuses on obsessive neurosis in Melanie Klein's. Thus, it was also possible to study a historical broad view of the construction of this author's thought, having in mind that a chronological itinerary was followed, and, as an important consequence, an epistemological dimension of this construction was obtained. This was so because the obsessive neurosis constitutes an outstanding organizing element in Klein's work, mainly in the 1920's and 30's. This time was marked by the observation of the author's first patients, who were, in their majority, children suffering from obsessive neurosis.

  1. CV equipment responsibilities

    CERN Document Server

    Pirollet, B

    2008-01-01

    This document describes the limits of the responsibilities of the TS/CV for fire fighting equipment at the LHC. The various interfaces, providers and users of the water supply systems and clean water raising systems are described.

  2. Simulation of density measurements in plasma wakefields using photo acceleration

    CERN Document Server

    Kasim, Muhammad Firmansyah; Ceurvorst, Luke; Sadler, James; Burrows, Philip N; Trines, Raoul; Holloway, James; Wing, Matthew; Bingham, Robert; Norreys, Peter

    2015-01-01

    One obstacle in plasma accelerator development is the limitation of techniques to diagnose and measure plasma wakefield parameters. In this paper, we present a novel concept for the density measurement of a plasma wakefield using photon acceleration, supported by extensive particle in cell simulations of a laser pulse that copropagates with a wakefield. The technique can provide the perturbed electron density profile in the laser’s reference frame, averaged over the propagation length, to be accurate within 10%. We discuss the limitations that affect the measurement: small frequency changes, photon trapping, laser displacement, stimulated Raman scattering, and laser beam divergence. By considering these processes, one can determine the optimal parameters of the laser pulse and its propagation length. This new technique allows a characterization of the density perturbation within a plasma wakefield accelerator.

  3. Simulation of density measurements in plasma wakefields using photon acceleration

    Directory of Open Access Journals (Sweden)

    Muhammad Firmansyah Kasim

    2015-03-01

    Full Text Available One obstacle in plasma accelerator development is the limitation of techniques to diagnose and measure plasma wakefield parameters. In this paper, we present a novel concept for the density measurement of a plasma wakefield using photon acceleration, supported by extensive particle in cell simulations of a laser pulse that copropagates with a wakefield. The technique can provide the perturbed electron density profile in the laser’s reference frame, averaged over the propagation length, to be accurate within 10%. We discuss the limitations that affect the measurement: small frequency changes, photon trapping, laser displacement, stimulated Raman scattering, and laser beam divergence. By considering these processes, one can determine the optimal parameters of the laser pulse and its propagation length. This new technique allows a characterization of the density perturbation within a plasma wakefield accelerator.

  4. Emgu CV essentials

    CERN Document Server

    Shi, Shin

    2013-01-01

    This book provides a practical guide to Emgu CV libraries, with sample code and examples used throughout to explain the concepts clearly. Each chapter deals with a different aspect of the Computer Vision field and the implementation of that topic in Emgu CV.If you are a C# programmer working on computer vision projects, this book is for you. You should have prior experience with C#.

  5. Transverse wakefield of waveguide damped structures and beam dynamics

    International Nuclear Information System (INIS)

    Lin, X.

    1995-08-01

    In the design of new high energy particle colliders with higher luminosity one is naturally led to consider multi-bunch operation. However, the passage of a leading bunch through an accelerator cavity Generates a wakefield that may have a deleterious effect on the motion of the subsequent bunches. Therefore, the suppression of the wakefield is an essential requirement for beam stability. One solution to this problem, which has been studied extensively is to drain the wakefield energy out of the cavity by means of waveguides coupled with the cavity and fed into matched terminations. Waveguide dimensions are chosen to yield a cutoff frequency well above the frequency of the accelerating mode so that the latter is undamped. This paper presents a thorough investigation of the wakefield for this configuration. The effectiveness of waveguide damping has typically been assessed by evaluating the resultant Q ext of higher order cavity modes to determine their exponential damping rate. We have developed an efficient method to calculate Q ext of the damped modes from popular computer simulation codes such as MAFIA. This method has been successively applied to the B-factory RF cavity We have also found another type of wakefield, associated with waveguide cut-off, which decays as t -3/2 rather than in the well-known exponentially damped manner. Accordingly, we called it the persistent Wakefield. A similar phenomenon with essentially the same physical origin but occurring in the decay of unstable quantum states, has received extensive study. Then we have developed various methods of calculating this persistent wakefield, including mode matching and computer simulation. Based on a circuit model we estimate the limit that waveguide damping can reach to reduce the wakefield

  6. Final Report: Experimental Investigation of Nonlinear Plasma Wake-Fields

    International Nuclear Information System (INIS)

    Rosenzweig, J.

    1997-01-01

    We discuss the exploration of the newly proposed blowout regime of the plasma wakefield accelerator and advanced photoinjector technology for linear collider applications. The plasma wakefield experiment at ANL produced several ground-breaking results in the physics of the blowout regime. The photoinjector R and D effort produced breakthroughs in theoretical, computational, and experimental methods in high brightness beam physics. Results have been published

  7. Introduction to wakefields and wake potentials

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, P.B.

    1989-01-01

    What are wakefields and wake potentials, and why are these concepts useful in the physics of linear accelerators and storage rings We approach this question by first reviewing the basic physical concepts which underlie the mathematical formalism. We then present a summary of the various techniques that have been developed to make detailed calculations of wake potentials. Finally, we give some applications to current problems of interest in accelerator physics. No attempt at completeness can be made in an introductory article of modest length. Rather, we try to give a broad overview and to list key references for more detailed study. It will also be apparent that the last chapter on this subject, with all the loose ends neatly tied up, has yet to be written. There are subtle points, there are controversial questions, and active calculations to resolve these questions are continuing at the time of this writing. 61 refs., 10 figs., 1 tab.

  8. Introduction to wakefields and wake potentials

    International Nuclear Information System (INIS)

    Wilson, P.B.

    1989-01-01

    What are wakefields and wake potentials, and why are these concepts useful in the physics of linear accelerators and storage rings? We approach this question by first reviewing the basic physical concepts which underlie the mathematical formalism. We then present a summary of the various techniques that have been developed to make detailed calculations of wake potentials. Finally, we give some applications to current problems of interest in accelerator physics. No attempt at completeness can be made in an introductory article of modest length. Rather, we try to give a broad overview and to list key references for more detailed study. It will also be apparent that the last chapter on this subject, with all the loose ends neatly tied up, has yet to be written. There are subtle points, there are controversial questions, and active calculations to resolve these questions are continuing at the time of this writing. 61 refs., 10 figs., 1 tab

  9. Wakefield monitor development for CLIC accelerating structure

    CERN Document Server

    Peauger, F; Girardot, P; Andersson, A; Riddone, G; Samoshkin, A; Solodko, A; Zennaro, R; Ruber, R

    2010-01-01

    Abstract To achieve high luminosity in CLIC, the accelerating structures must be aligned to an accuracy of 5 μm with respect to the beam trajectory. Position detectors called Wakefield Monitors (WFM) are integrated to the structure for a beam based alignment. This paper describes the requirements of such monitors. Detailed RF design and electromagnetic simulations of the WFM itself are presented. In particular, time domain computations are performed and an evaluation of the resolution is done for two higher order modes at 18 and 24 GHz. The mechanical design of a prototype accelerating structure with WFM is also presented as well as the fabrication status of three complete structures. The objective is to implement two of them in CTF3 at CERN for a feasibility demonstration with beam and high power rf.

  10. WAKEFIELD DAMPING FOR THE CLIC CRAB CAVITY

    CERN Document Server

    Ambattu, P; Dexter, A; Carter, R; Khan, V; Jones, R; Dolgashev, V

    2009-01-01

    A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab cavity are inversely proportional to the operating frequency. The short bunch spacing of the CLIC scheme and the high sensitivity of the crab cavity to dipole kicks demand very high damping of the inter-bunch wakes, the major contributor to the luminosity loss of colliding bunches. This paper investigates the nature of the wakefields in the CLIC crab cavity and the possibility of using various damping schemes to suppress them effectively.

  11. Novel gas target for laser wakefield accelerators

    Science.gov (United States)

    Aniculaesei, C.; Kim, Hyung Taek; Yoo, Byung Ju; Oh, Kyung Hwan; Nam, Chang Hee

    2018-02-01

    A novel gas target for interactions between high power lasers and gaseous medium, especially for laser wakefield accelerators, has been designed, manufactured, and characterized. The gas target has been designed to provide a uniform density profile along the central gas cell axis by combining a gas cell and slit nozzle. The gas density has been tuned from ˜1017 atoms/cm3 to ˜1019 atoms/cm3 and the gas target length can be varied from 0 to 10 cm; both changes can be made simultaneously while keeping the uniform gas profile. The gas density profile inside the gas cell has been measured using interferometry and validated using computational fluid dynamics.

  12. Probing plasma wakefields using electron bunches generated from a laser wakefield accelerator

    Science.gov (United States)

    Zhang, C. J.; Wan, Y.; Guo, B.; Hua, J. F.; Pai, C.-H.; Li, F.; Zhang, J.; Ma, Y.; Wu, Y. P.; Xu, X. L.; Mori, W. B.; Chu, H.-H.; Wang, J.; Lu, W.; Joshi, C.

    2018-04-01

    We show experimental results of probing the electric field structure of plasma wakes by using femtosecond relativistic electron bunches generated from a laser wakefield accelerator. Snapshots of laser-driven linear wakes in plasmas with different densities and density gradients are captured. The spatiotemporal evolution of the wake in a plasma density up-ramp is recorded. Two parallel wakes driven by a laser with a main spot and sidelobes are identified in the experiment and reproduced in simulations. The capability of this new method for capturing the electron- and positron-driven wakes is also shown via 3D particle-in-cell simulations.

  13. Lacan leitor de Melanie Klein: O caso Dick em questão

    OpenAIRE

    Lucero, Ariana; Vorcaro, Angela Maria Resende

    2017-01-01

    RESUMO - O artigo apresenta a leitura que Jacques Lacan faz do caso Dick, de Melanie Klein. Para tanto, a discussão com o flósofo Jean Hyppolite é retomada com o objetivo de explicitarmos como os mecanismos de Ausstossung [expulsão], Verneinung [negação] e Bejahung [afrmação], descritos por Freud em 1925, podem contribuir para a compreensão da constituição psíquicasob uma perspectiva lacaniana. Em seguida, expomos o caso, tanto para apreendermos clinicamente o que foi exposto na teoria, quant...

  14. Between practice and theory: Melanie Klein, Anna Freud and the development of child analysis.

    Science.gov (United States)

    Donaldson, G

    1996-04-01

    An examination of the early history of child analysis in the writings of Melanie Klein and Anna Freud reveals how two different and opposing approaches to child analysis arose at the same time. The two methods of child analysis are rooted in a differential emphasis on psychoanalytic theory and practice. The Kleinian method derives from the application of technique while the Anna Freudian method is driven by theory. Furthermore, by holding to the Freudian theory of child development Anna Freud was forced to limit the scope of child analysis, while Klein's application of Freudian practice has led to new discoveries about the development of the infant psyche.

  15. Vicious circles of punishment: a reading of Melanie Klein's Envy and gratitude.

    Science.gov (United States)

    Smith, Henry F

    2008-01-01

    Staged as a moral drama, Melanie Klein's Envy and Gratitude (1957) straddles two eras: one reflecting a simpler more concrete, historical method, and the other an approach of greater complexity, focused on the transferential moment. Embedded within the transference are the vicious circles of envy and punishment that are the hallmark of Klein's text. Punishment itself which is always punishment of both self and other, creates its own vicious circle, set in motion by a single act. In the sadomasochistic enactments that result, the moral force of Klein's categories fuels the countertransference. A detailed clinical hour is presented.

  16. CV : [luuletused] / Mari Vallisoo

    Index Scriptorium Estoniae

    Vallisoo, Mari, 1950-2013

    2007-01-01

    Sisu: CV ; Sõnaraamat ; Tegijad ; "Kus leemekulp?..." ; "Veel üks viimnepäev mis asja teha sellega..." ; "Ülemise riiuli ääre pääl...", "Alkeemik Alberti elamus...", "Valge pulber veel enam valgega...", "Meie isa, kes sa...", "Ükskord, kui Maa...", "Kevadvesi ja -pori...", "Mõisnik Meeskurat müüs mu vaarisale..."

  17. Wake-field studies on photonic band gap accelerator cavities

    International Nuclear Information System (INIS)

    Li, D.; Kroll, N.; Stanford Linear Accelerator Center, M/S 26, P.O. Box 4349, Stanford, California; Smith, D.R.; Schultz, S.

    1997-01-01

    We have studied the wake-field of several metal Photonic Band Gap (PBG) cavities which consist of either a square or a hexagonal array of metal cylinders, bounded on top and bottom by conducting or superconducting sheets, surrounded by placing microwave absorber at the periphery or by replacing outer rows of metal cylinders with lossy dielectric ones, or by metallic walls. A removed cylinder from the center of the array constitutes a site defect where a localized electromagnetic mode can occur. While both monopole and dipole wake-fields have been studied, we confine our attention here mainly to the dipole case. The dipole wake-field is produced by modes in the propagation bands which tend to fill the entire cavity more or less uniformly and are thus easy to damp selectively. MAFIA time domain simulation of the transverse wake-field has been compared with that of a cylindrical pill-box comparison cavity. Even without damping the wake-field of the metal PBG cavity is substantially smaller than that of the pill-box cavity and may be further reduced by increasing the size of the lattice. By introducing lossy material at the periphery we have been able to produce Q factors for the dipole modes in the 40 to 120 range without significantly degrading the accelerating mode. copyright 1997 American Institute of Physics

  18. Femtosecond electron-bunch dynamics in laser wakefields and vacuum

    Directory of Open Access Journals (Sweden)

    A. G. Khachatryan

    2007-12-01

    Full Text Available Recent advances in laser wakefield acceleration demonstrated the generation of extremely short (with a duration of a few femtoseconds relativistic electron bunches with relatively low (of the order of couple of percent energy spread. In this article we study the dynamics of such bunches in drift space (vacuum and in channel-guided laser wakefields. Analytical solutions were found for the transverse coordinate of an electron and for the bunch envelope in the wakefield in the case of arbitrary change in the energy. Our results show strong bunch dynamics already on a millimeter scale propagation distance both in plasma and in vacuum. When the bunch propagates in vacuum, its transverse sizes grow considerably; the same is observed for the normalized bunch emittance that worsens the focusability of the bunch. A scheme of two-stage laser wakefield accelerator with small drift space between the stages is proposed. It is found that fast longitudinal betatron phase mixing occurs in a femtosecond bunch when it propagates along the wakefield axis. When bunch propagates off axis, strong bunch decoherence and fast emittance degradation due to the finite bunch length was observed.

  19. Quantitative comparison and evaluation of two commercially available, two-dimensional electrophoresis image analysis software packages, Z3 and Melanie.

    Science.gov (United States)

    Raman, Babu; Cheung, Agnes; Marten, Mark R

    2002-07-01

    While a variety of software packages are available for analyzing two-dimensional electrophoresis (2-DE) gel images, no comparisons between these packages have been published, making it difficult for end users to determine which package would best meet their needs. The goal here was to develop a set of tests to quantitatively evaluate and then compare two software packages, Melanie 3.0 and Z3, in three of the fundamental steps involved in 2-DE image analysis: (i) spot detection, (ii) gel matching, and (iii) spot quantitation. To test spot detection capability, automatically detected protein spots were compared to manually counted, "real" protein spots. Spot matching efficiency was determined by comparing distorted (both geometrically and nongeometrically) gel images with undistorted original images, and quantitation tests were performed on artificial gels with spots of varying Gaussian volumes. In spot detection tests, Z3 performed better than Melanie 3.0 and required minimal user intervention to detect approximately 89% of the actual protein spots and relatively few extraneous spots. Results from gel matching tests depended on the type of image distortion used. For geometric distortions, Z3 performed better than Melanie 3.0, matching 99% of the spots, even for extreme distortions. For nongeometrical distortions, both Z3 and Melanie 3.0 required user intervention and performed comparably, matching 95% of the spots. In spot quantitation tests, both Z3 and Melanie 3.0 predicted spot volumes relatively well for spot ratios less than 1:6. For higher ratios, Melanie 3.0 did much better. In summary, results suggest Z3 requires less user intervention than Melanie 3.0, thus simplifying differential comparison of 2-DE gel images. Melanie 3.0, however, offers many more optional tools for image editing, spot detection, data reporting and statistical analysis than Z3. All image files used for these tests and updated information on the software are available on the internet

  20. Wakefields in the LCLS Undulator Transitions

    Energy Technology Data Exchange (ETDEWEB)

    Bane, Karl L.F.; /SLAC; Zagorodnov, Igor A.; /DESY

    2005-08-15

    We have studied longitudinal wakefields of very short bunches in non-cylindrically symmetric (3D) vacuum chamber transitions using analytical models and the computer program ECHO. The wake (for pairs of well-separated, non-smooth transitions) invariably is resistive, with its shape proportional to the bunch distribution. For the example of an elliptical collimator in a round beam pipe we have demonstrated that--as in the cylindrically symmetric (2D) case--the wake can be obtained from the static primary field of the beam alone. We have obtained the wakes of the LCLS rectangular-to-round transitions using indirect (numerical) field integration combined with a primary beam field calculation. For the LCLS 1 nC bunch charge configuration we find that the total variation in wake-induced energy change is small (0.03% in the core of the beam, 0.15% in the horns of the distribution) compared to that due to the resistive wall wakes of the undulator beam pipe (0.6%).

  1. Julia Kristeva: Das weibliche Genie – Melanie Klein. Gießen: Psychosozial-Verlag 2008

    Directory of Open Access Journals (Sweden)

    Lilli Gast

    2009-07-01

    Full Text Available Julia Kristeva widmet sich im zweiten Teil ihrer Trilogie über das weibliche Genie dem Leben und Werk von Melanie Klein, die mit ihren Arbeiten über die früheste Verfasstheit des Psychischen das psychoanalytische Denken für die Psychosen und den Wahn aufschloss und die Rolle des Mütterlichen im psychoanalytischen Diskurs neu definierte. In ihrer Auseinandersetzung mit Klein gelingt Kristeva nicht nur eine ausgesprochen gelungene Einführung in Kleins Denken, sondern auch eine Analyse weiblicher Intellektualität im 20. Jahrhundert. Zudem werden die Schnittstellen im Denken Kleins und Kristevas sichtbar.Julia Kristeva devotes this second installment of her trilogy on feminine genius to the life and work of Melanie Klein. Klein’s work on the early state of the psyche opened psychoanalytical thinking to psychoses, delusion, and the redefined the role of the motherly in psychoanalytical discourse. In her discussion of Klein, Kristeva provides not only a markedly insightful introduction to Klein’s thinking, but also an analysis of female intellectuality in the 20th century. Moreover, the reader clearly sees the interconnections between Klein and Kristeva’s thinking.

  2. Electron injection by evolution of self-modulated laser wakefields

    International Nuclear Information System (INIS)

    Kim, Changbum; Kim, Guang-Hoon; Kim, Jong-Uk; Lee, Hae June; Suk, Hyyong; Ko, In Soo

    2003-01-01

    Self-injection mechanisms in the self-modulated laser wakefield acceleration (SM-LWFA) are investigated. Two-dimensional (2D) particle-in-cell (PIC) simulations show that a significant amount of plasma electrons can be self-injected into the acceleration phase of a laser wakefield by a dynamic increase in the wake wavelength in the longitudinal direction. In this process, it is found that the wake wavelength increases due to the relativistic effect and this leads to a large amount of electron injection into the wakefields. In this paper, the injection phenomena are studied with 2D simulations and a brief explanation of the new self-injection mechanism is presented. (author)

  3. Laser-driven wakefield electron acceleration and associated radiation sources

    International Nuclear Information System (INIS)

    Davoine, X.

    2009-10-01

    The first part of this research thesis introduces the basic concepts needed for the understanding of the laser-driven wakefield acceleration. It describes the properties of the used laser beams and plasmas, presents some notions about laser-plasma interactions for a better understanding of the physics of laser-driven acceleration. The second part deals with the numerical modelling and the presentation of simulation tools needed for the investigation of laser-induced wakefield acceleration. The last part deals with the optical control of the injection, a technique analogous to the impulsion collision scheme

  4. Electron-phonon coupling effect on wakefields in piezoelectric semiconductors

    International Nuclear Information System (INIS)

    Salimullah, M; Shukla, P K; Ghosh, S K; Nitta, H; Hayashi, Y

    2003-01-01

    Using an appropriate dielectric constant for an n-type piezoelectric semiconductor plasma and a moving test particle approach, it is shown that, besides the usual screened potential, there exists a non-Coulombian oscillatory potential or a wakefield behind a moving charged particle due to a strong resonant interaction between the charged particle and the electro-acoustic mode of the host semiconductor. With the concept of the wakefield, a possible lattice formation of colloids resulting from ion implantation in a current-carrying piezoelectric semiconductor has been examined

  5. Recovery of CTF beam signals from a strong wakefield background

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Y [TRIUMF, Vancouver, BC (Canada); Schulte, E [European Organization for Nuclear Research, Geneva (Switzerland); Ekeloef, T [Uppsala Univ. (Sweden)

    1995-06-01

    The beam monitor for the CERN Linear Collider Test Facility (CTF) has to work not only with very short pulses (350 ps FWHM) at a spacing of 330 ps, but also in a strong wakefield background. A cone-shaped button pickup electrode has been designed and constructed for use with CTF beams and tests have been made using a real time analogue Gaussian filter to recover the beam signals from the strong wakefield signals. As a comparison to the analogue filter, a study has been made to process the data off-line and extract the beam signals using digital filtering based on the wavelet concept. (author). 3 refs., 7 figs.

  6. γ -Ray Generation from Plasma Wakefield Resonant Wiggler

    Science.gov (United States)

    Lei, Bifeng; Wang, Jingwei; Kharin, Vasily; Zepf, Matt; Rykovanov, Sergey

    2018-03-01

    A flexible gamma-ray radiation source based on the resonant laser-plasma wakefield wiggler is proposed. The wiggler is achieved by inducing centroid oscillations of a short laser pulse in a plasma channel. Electrons (self-)injected in such a wakefield experience both oscillations due to the transverse electric fields and energy gain due to the longitudinal electric field. The oscillations are significantly enhanced when the laser pulse centroid oscillations are in resonance with the electron betatron oscillations, extending the radiation spectrum to the gamma-ray range. The polarization of the radiation can be easily controlled by adjusting the injection of the laser pulse into the plasma channel.

  7. Hot spots and dark current in advanced plasma wakefield accelerators

    Directory of Open Access Journals (Sweden)

    G. G. Manahan

    2016-01-01

    Full Text Available Dark current can spoil witness bunch beam quality and acceleration efficiency in particle beam-driven plasma wakefield accelerators. In advanced schemes, hot spots generated by the drive beam or the wakefield can release electrons from higher ionization threshold levels in the plasma media. These electrons may be trapped inside the plasma wake and will then accumulate dark current, which is generally detrimental for a clear and unspoiled plasma acceleration process. Strategies for generating clean and robust, dark current free plasma wake cavities are devised and analyzed, and crucial aspects for experimental realization of such optimized scenarios are discussed.

  8. Laser wakefield accelerator based light sources: potential applications and requirements

    Energy Technology Data Exchange (ETDEWEB)

    Albert, F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). NIF and Photon Sciences; Thomas, A. G. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences; Mangles, S. P.D. [Imperial College, London (United Kingdom). Blackett Lab.; Banerjee, S. [Univ. of Nebraska, Lincoln, NE (United States); Corde, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Flacco, A. [ENSTA, CNRS, Ecole Polytechnique, Palaiseau (France); Litos, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Neely, D. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Viera, J. [Univ. of Lisbon (Portugal). GoLP-Inst. de Plasmas e Fusao Nuclear-Lab. Associado; Najmudin, Z. [Imperial College, London (United Kingdom). Blackett Lab.; Bingham, R. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Joshi, C. [Univ. of California, Los Angeles, CA (United States). Dept. of Electrical Engineering; Katsouleas, T. [Duke Univ., Durham, NC (United States). Platt School of Engineering

    2015-01-15

    In this article we review the prospects of laser wakefield accelerators as next generation light sources for applications. This work arose as a result of discussions held at the 2013 Laser Plasma Accelerators Workshop. X-ray phase contrast imaging, X-ray absorption spectroscopy, and nuclear resonance fluorescence are highlighted as potential applications for laser-plasma based light sources. We discuss ongoing and future efforts to improve the properties of radiation from plasma betatron emission and Compton scattering using laser wakefield accelerators for these specific applications.

  9. Scaling laws of design parameters for plasma wakefield accelerators

    International Nuclear Information System (INIS)

    Uhm, Han S.; Nam, In H.; Suk, Hyyong

    2012-01-01

    Simple scaling laws for the design parameters of plasma wakefield accelerators were obtained using a theoretical model, which were confirmed via particle simulation studies. It was found that the acceleration length was given by Δx=0.804λ p /(1−β g ), where λ p is the plasma wavelength and β g c the propagation velocity of the ion cavity. The acceleration energy can also be given by ΔE=(γ m −1)mc 2 =2.645mc 2 /(1−β g ), where m is the electron rest mass. As expected, the acceleration length and energy increase drastically as β g approached unity. These simple scaling laws can be very instrumental in the design of better-performing plasma wakefield accelerators. -- Highlights: ► Simple scaling laws for the design parameters of laser wakefield accelerators were obtained using a theoretical model. ► The scaling laws for acceleration length and acceleration energy were compared with particle-in-cell simulation results. ► The acceleration length and the energy increase drastically as β g approaches unity. ► These simple scaling laws can be very instrumental in the design of laser wakefield accelerators.

  10. LTRACK: Beam-transport calculation including wakefield effects

    International Nuclear Information System (INIS)

    Chan, K.C.D.; Cooper, R.K.

    1988-01-01

    LTRACK is a first-order beam-transport code that includes wakefield effects up to quadrupole modes. This paper will introduce the readers to this computer code by describing the history, the method of calculations, and a brief summary of the input/output information. Future plans for the code will also be described

  11. A high current, short pulse electron source for wakefield accelerators

    International Nuclear Information System (INIS)

    Ho, Ching-Hung.

    1992-01-01

    Design studies for the generation of a high current, short pulse electron source for the Argonne Wakefield Accelerator are presented. An L-band laser photocathode rf gun cavity is designed using the computer code URMEL to maximize the electric field on the cathode surface for fixed frequency and rf input power. A new technique using a curved incoming laser wavefront to minimize the space charge effect near the photocathode is studied. A preaccelerator with large iris to minimize wakefield effects is used to boost the drive beam to a useful energy of around 20 MeV for wakefield acceleration experiments. Focusing in the photocathode gun and the preaccelerator is accomplished with solenoids. Beam dynamics simulations throughout the preaccelerator are performed using particle simulation codes TBCI-SF and PARMELA. An example providing a useful set of operation parameters for the Argonne Wakefield Accelerator is given. The effects of the sagitta of the curved beam and laser amplitude and timing jitter effects are discussed. Measurement results of low rf power level bench tests and a high power test for the gun cavity are presented and discussed

  12. Good and Bad: Love and Intimacy From Plato to Melanie Klein.

    Science.gov (United States)

    Stromberg, David

    2018-06-01

    Melanie Klein's theories on love outline a complex system of relations-an oscillating dynamic of psychical and emotional tendencies following from both actual experience and fantasies produced by the mind. Her insights are often discussed and applied in psychoanalytical contexts, but the philosophical implications of her theory-especially in relation to Platonic thought-have rarely been discussed. In this article, I will attempt to address this gap by setting out some preliminary yet core considerations shared by both Plato and Klein. First, I will describe some structural parallels between Kleinian and Platonic thought, especially in dialectical terms. Second, I will outline Plato's covert influence on Freud as passing through the teachings of philosopher Franz Brentano. And last, I will discuss intimacy as a struggle between the forces of good and bad, creativity and destruction, and love and hate-suggesting that Klein's conception of love emerges as a moral exigency.

  13. Some observations on hallucination: clinical application of some developments of Melanie Klein's work.

    Science.gov (United States)

    Taylor, D

    1983-01-01

    The analysis of a psychotic patient is used to illustrate the importance of certain developments of Melanie Klein's work. The case presentation focuses upon the formal qualities of the patient's communications, many of which were amalgamations of profoundly incompatible elements, particularly a subtle destructiveness which parasitized seemingly impartial reports about her state of mind. These communications embodied important object relationships. The patient used her communications to conjure up psychic disintegration. As a result of her involvement in 'chuntering' her preoccupations would become increasingly violent, cruel and sexualized. The patient's equivocal communications generate confusion. This is central to the patient's experience of self-destruction as persecution. A number of ideas are advanced concerning the origins of the patient's hallucinations. These include her relish at the introduction of sensory distortions. Questions are raised about the nature of certain types of hallucination, the origins and intractability of concrete thinking, about verbalization and about the typology of psychotic patients.

  14. Long-term evolution of broken wakefields in finite radius plasmas

    CERN Document Server

    Lotov, Konstantin; Petrenko, Alexey

    2014-01-01

    A novel effect of fast heating and charging a finite-radius plasma is discovered in the context of plasma wakefield acceleration. As the plasma wave breaks, the most of its energy is transferred to plasma electrons which create strong charge-separation electric field and azimuthal magnetic field around the plasma. The slowly varying field structure is preserved for hundreds of wakefield periods and contains (together with hot electrons) up to 80% of the initial wakefield energy.

  15. Supersonic jets of hydrogen and helium for laser wakefield acceleration

    CERN Document Server

    Svensson, K.; Wojda, F.; Senje, L.; Burza, M.; Aurand, B.; Genoud, G.; Persson, A.; Wahlström, C.-G.; Lundh, O.

    2016-01-01

    The properties of laser wakefield accelerated electrons in supersonic gas flows of hydrogen and helium are investigated. At identical backing pressure, we find that electron beams emerging from helium show large variations in their spectral and spatial distributions, whereas electron beams accelerated in hydrogen plasmas show a higher degree of reproducibility. In an experimental investigation of the relation between neutral gas density and backing pressure, it is found that the resulting number density for helium is ∼30% higher than for hydrogen at the same backing pressure. The observed differences in electron beam properties between the two gases can thus be explained by differences in plasma electron density. This interpretation is verified by repeating the laser wakefield acceleration experiment using similar plasma electron densities for the two gases, which then yielded electron beams with similar properties.

  16. Status of Wakefield Monitor Experiments at the CLIC Test Facility

    CERN Document Server

    Lillestøl, Reidar; Aftab, Namra; Corsini, Roberto; Döbert, Steffen; Farabolini, Wilfrid; Grudiev, Alexej; Javeed, Sumera; Pfingstner, Juergen; Wuensch, Walter

    2016-01-01

    For the very low emittance beams in CLIC, it is vital to mitigate emittance growth which leads to reduced luminosity in the detectors. One factor that leads to emittance growth is transverse wakefields in the accelerating structures. In order to combat this the structures must be aligned with a precision of a few um. For achieving this tolerance, accelerating structures are equipped with wakefield monitors that measure higher-order dipole modes excited by the beam when offset from the structure axis. We report on such measurements, performed using prototype CLIC accelerating structures which are part of the module installed in the CLIC Test Facility 3 (CTF3) at CERN. Measurements with and without the drive beam that feeds rf power to the structures are compared. Improvements to the experimental setup are discussed, and finally remaining measurements that should be performed before the completion of the program are summarized.

  17. On wakefields with two-dimensional planar geometry

    International Nuclear Information System (INIS)

    Chao, A.W.; Bane, K.L.F.

    1996-10-01

    In order to reach higher acceleration gradients in linear accelerators, it is advantageous to use a higher accelerating RF frequency, which in turn requires smaller accelerating structures. As the structure size becomes smaller, rectangular structures become increasingly interesting because they are easier to construct than cylindrically symmetric ones. One drawback of small structures, however, is that the wakefields generated by the beam in such structures tend to be strong. Recently, it has been suggested that one way of ameliorating this problem is to use rectangular structures that are very flat and to use flat beams. In the limiting case of a very flat planar geometry, the problem resembles a purely two-dimensional (2-D) problem, the wakefields of which have been studied

  18. A preliminary design of the collinear dielectric wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Zholents, A.; Gai, W.; Doran, S.; Lindberg, R.; Power, J.G.; Strelnikov, N.; Sun, Y.; Trakhtenberg, E.; Vasserman, I. [ANL, Argonne, IL 60439 (United States); Jing, C.; Kanareykin, A.; Li, Y. [Euclid Techlabs LLC, Solon, OH 44139 (United States); Gao, Q. [Tsinghua University, Beijing (China); Shchegolkov, D.Y.; Simakov, E.I. [LANL, Los Alamos, NM 87545 (United States)

    2016-09-01

    A preliminary design of the multi-meter long collinear dielectric wakefield accelerator that achieves a highly efficient transfer of the drive bunch energy to the wakefields and to the witness bunch is considered. It is made from ~0.5 m long accelerator modules containing a vacuum chamber with dielectric-lined walls, a quadrupole wiggler, an rf coupler, and BPM assembly. The single bunch breakup instability is a major limiting factor for accelerator efficiency, and the BNS damping is applied to obtain the stable multi-meter long propagation of a drive bunch. Numerical simulations using a 6D particle tracking computer code are performed and tolerances to various errors are defined.

  19. Radiation pressure injection in laser-wakefield acceleration

    Science.gov (United States)

    Liu, Y. L.; Kuramitsu, Y.; Isayama, S.; Chen, S. H.

    2018-01-01

    We investigated the injection of electrons in laser-wakefield acceleration induced by a self-modulated laser pulse by a two dimensional particle-in-cell simulation. The localized electric fields and magnetic fields are excited by the counter-streaming flows on the surface of the ion bubble, owing to the Weibel or two stream like instability. The electrons are injected into the ion bubble from the sides of it and then accelerated by the wakefield. Contrary to the conventional wave breaking model, the injection of monoenergetic electrons are mainly caused by the electromagnetic process. A simple model was proposed to address the instability, and the growth rate was verified numerically and theoretically.

  20. Supersonic jets of hydrogen and helium for laser wakefield acceleration

    Directory of Open Access Journals (Sweden)

    K. Svensson

    2016-05-01

    Full Text Available The properties of laser wakefield accelerated electrons in supersonic gas flows of hydrogen and helium are investigated. At identical backing pressure, we find that electron beams emerging from helium show large variations in their spectral and spatial distributions, whereas electron beams accelerated in hydrogen plasmas show a higher degree of reproducibility. In an experimental investigation of the relation between neutral gas density and backing pressure, it is found that the resulting number density for helium is ∼30% higher than for hydrogen at the same backing pressure. The observed differences in electron beam properties between the two gases can thus be explained by differences in plasma electron density. This interpretation is verified by repeating the laser wakefield acceleration experiment using similar plasma electron densities for the two gases, which then yielded electron beams with similar properties.

  1. Modulation of continuous electron beams in plasma wake-fields

    International Nuclear Information System (INIS)

    Rosenzweig, J.B.

    1988-01-01

    In this paper we discuss the interaction of a continuous electron beam with wake-field generated plasma waves. Using a one-dimensional two fluid model, a fully nonlinear analytical description of the interaction is obtained. The phenomena of continuous beam modulation and wave period shortening are discussed. The relationship between these effects and the two-stream instability is also examined. 12 refs., 1 fig

  2. Dielectric Wakefield Accelerator to drive the future FEL Light Source.

    Energy Technology Data Exchange (ETDEWEB)

    Jing, C.; Power, J.; Zholents, A. (Accelerator Systems Division (APS)); ( HEP); (LLC)

    2011-04-20

    X-ray free-electron lasers (FELs) are expensive instruments and a large part of the cost of the entire facility is driven by the accelerator. Using a high-energy gain dielectric wake-field accelerator (DWA) instead of the conventional accelerator may provide a significant cost saving and reduction of the facility size. In this article, we investigate using a collinear dielectric wakefield accelerator to provide a high repetition rate, high current, high energy beam to drive a future FEL x-ray light source. As an initial case study, a {approx}100 MV/m loaded gradient, 850 GHz quartz dielectric based 2-stage, wakefield accelerator is proposed to generate a main electron beam of 8 GeV, 50 pC/bunch, {approx}1.2 kA of peak current, 10 x 10 kHz (10 beamlines) in just 100 meters with the fill factor and beam loading considered. This scheme provides 10 parallel main beams with one 100 kHz drive beam. A drive-to-main beam efficiency {approx}38.5% can be achieved with an advanced transformer ratio enhancement technique. rf power dissipation in the structure is only 5 W/cm{sup 2} in the high repetition rate, high gradient operation mode, which is in the range of advanced water cooling capability. Details of study presented in the article include the overall layout, the transform ratio enhancement scheme used to increase the drive to main beam efficiency, main wakefield linac design, cooling of the structure, etc.

  3. Coaxial two-channel high-gradient dielectric wakefield accelerator

    Directory of Open Access Journals (Sweden)

    G. V. Sotnikov

    2009-06-01

    Full Text Available A new scheme for a dielectric wakefield accelerator is proposed that employs a cylindrical multizone dielectric structure configured as two concentric dielectric tubes with outer and inner vacuum channels for drive and accelerated bunches. Analytical and numerical studies have been carried out for such coaxial dielectric-loaded structures (CDS for high-gradient acceleration. An analytical theory of wakefield excitation by particle bunches in a multizone CDS has been formulated. Numerical calculations are presented for an example of a CDS using dielectric tubes with dielectric permittivity 5.7, having external diameters of 2.121 and 0.179 mm with inner diameters of 2.095 and 0.1 mm. An annular 5 GeV, 6 nC electron bunch with rms length of 0.035 mm energizes a wakefield on the structure axis having an accelerating gradient of ∼600  MeV/m with a transformer ratio ∼8∶1. The period of the accelerating field is ∼0.33  mm. If the width of the drive bunch channel is decreased, it is possible to obtain an accelerating gradient of >1  GeV/m while keeping the transformer ratio approximately the same. Full numerical simulations using a particle-in-cell code have confirmed results of the linear theory and furthermore have shown the important influence of the quenching wave that restricts the region of the wakefield to within several periods following the drive bunch. Numerical simulations for another example have shown nearly stable transport of drive and accelerated bunches through the CDS, using a short train of drive bunches.

  4. Proof on principle experiments of laser wakefield acceleration

    International Nuclear Information System (INIS)

    Nakajima, K.; Kawakubo, T.; Nakanishi, H.

    1994-01-01

    The principle of laser wakefield particle acceleration has been tested by the Nd:glass laser system providing a short pulse with a power of 10 TW and a duration of 1 ps. Electrons accelerated up to 18 MeV/c have been observed by injecting 1 MeV/c electrons emitted from a solid target by an intense laser impact. The accelerating field gradient of 30 GeV/m is inferred. (author)

  5. Demonstration of the hollow channel plasma wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Gessner, Spencer J.

    2016-09-17

    A plasma wakefield accelerator is a device that converts the energy of a relativistic particle beam into a large-amplitude wave in a plasma. The plasma wave, or wakefield, supports an enormous electricfield that is used to accelerate a trailing particle beam. The plasma wakefield accelerator can therefore be used as a transformer, transferring energy from a high-charge, low-energy particle beam into a high-energy, low-charge particle beam. This technique may lead to a new generation of ultra-compact, high-energy particle accelerators. The past decade has seen enormous progress in the field of plasma wakefield acceleration with experimental demonstrations of the acceleration of electron beams by several gigaelectron-volts. The acceleration of positron beams in plasma is more challenging, but also necessary for the creation of a high-energy electron-positron collider. Part of the challenge is that the plasma responds asymmetrically to electrons and positrons, leading to increased disruption of the positron beam. One solution to this problem, first proposed over twenty years ago, is to use a hollow channel plasma which symmetrizes the response of the plasma to beams of positive and negative charge, making it possible to accelerate positrons in plasma without disruption. In this thesis, we describe the theory relevant to our experiment and derive new results when needed. We discuss the development and implementation of special optical devices used to create long plasma channels. We demonstrate for the first time the generation of meter-scale plasma channels and the acceleration of positron beams therein.

  6. Experimental studies of plasma wake-field acceleration and focusing

    International Nuclear Information System (INIS)

    Rosenzweig, J.B.; Cole, B.; Ho, C.; Argonne National Lab., IL

    1989-01-01

    More than four years after the initial proposal of the Plasma Wake-field Accelerator (PWFA), it continues to be the object of much investigation, due to the promise of the ultra-high accelerating gradients that can exist in relativistic plasma waves driven in the wake of charged particle beams. These large amplitude plasma wake-fields are of interest in the laboratory, both for the wealth of basic nonlinear plasma wave phenomena which can be studied, as well as for the applications of acceleration of focusing of electrons and positrons in future linear colliders. Plasma wake-field waves are also of importance in nature, due to their possible role in direct cosmic ray acceleration. The purpose of the present work is to review the recent experimental advances made in PWFA research at Argonne National Laboratory, in which many interesting beam and plasma phenomena have been observed. Emphasis is given to discussion of the nonlinear aspects of the PWFA beam-plasma interaction. 29 refs., 13 figs

  7. Radio-isotope production using laser Wakefield accelerators

    International Nuclear Information System (INIS)

    Leemans, W.P.; Rodgers, D.; Catravas, P.E.; Geddes, C.G.R.; Fubiani, G.; Toth, C.; Esarey, E.; Shadwick, B.A.; Donahue, R.; Smith, A.; Reitsma, A.

    2001-01-01

    A 10 Hz, 10 TW solid state laser system has been used to produce electron beams suitable for radio-isotope production. The laser beam was focused using a 30 cm focal length f/6 off-axis parabola on a gas plume produced by a high pressure pulsed gas jet. Electrons were trapped and accelerated by high gradient wakefields excited in the ionized gas through the self-modulated laser wakefield instability. The electron beam was measured to contain excesses of 5 nC/bunch. A composite Pb/Cu target was used to convert the electron beam into gamma rays which subsequently produced radio-isotopes through (gamma, n) reactions. Isotope identification through gamma-ray spectroscopy and half-life time measurements demonstrated that Cu 61 was produced which indicates that 20-25 MeV gamma rays were produced, and hence electrons with energies greater than 25-30 MeV. The production of high energy electrons was independently confirmed using a bending magnet spectrometer. The measured spectra had an exponential distribution with a 3 MeV width. The amount of activation was on the order of 2.5 uCi after 3 hours of operation at 1 Hz. Future experiments will aim at increasing this yield by post-accelerating the electron beam using a channel guided laser wakefield accelerator

  8. The Struggle of Integration: James Baldwin and Melanie Klein in the Context of Black Lives Matter

    Directory of Open Access Journals (Sweden)

    David W McIvor

    2016-12-01

    Full Text Available Recent killings of unarmed black citizens are a fresh reminder of the troubled state of racial integration in the United States. At the same time, the unfolding Black Lives Matter protest movements and the responses by federal agencies each testify to a not insignificant capacity for addressing social pathologies surrounding the color line. In order to respond to this ambivalent situation, this article suggests a pairing between the work of James Baldwin and that of the psychoanalyst Melanie Klein. I will argue that we cannot fully appreciate the depths of what Baldwin called the “savage paradox” of race without the insights provided by Klein and object relations psychoanalysis. Conversely, Baldwin helps us to sound out the political significance of object relations approaches, including the work of Klein and those influenced by her such as Hanna Segal and Wilfred Bion. In conversation with the work of Baldwin, object relations theory can help to identify particular social settings and institutions that might allow concrete efforts toward racial justice to take root.

  9. Implementation of the biomass gasification project for community empowerment at Melani village, Eastern Cape, South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Mamphweli, Ntshengedzeni S.; Meyer, Edson L. [University of Fort Hare, Institute of Technology, Private Bag X1314, Alice 5700 (South Africa)

    2009-12-15

    Eskom and the University of Fort Hare are engaged in a biomass gasification project using the System Johansson Biomass gasifier (SJBG). The SJBG installed at Melani village in the Eastern Cape province of South Africa is used to assess the viability and affordability of biomass gasification in South Africa. A community needs assessment study was undertaken at the village before the installation of the plant. The study revealed the need for low-cost electricity for small businesses including growing of crops, chicken broilers, manufacturing of windows and door frames, sewing of clothing, bakery etc. It was also found that the community had a problem with the socio-environmental aspects of burning biomass waste from the sawmill furnace as a means of waste management. The SJBG uses the excess biomass materials (waste) to generate low-cost electricity to drive community economic development initiatives. A study on the properties and suitability of the biomass materials resulting from sawmill operation and their suitability for gasification using the SJBG was undertaken. The study established that the biomass materials meet the requirements for the SJBG. A 300 Nm{sup 3}/h SJBG was then manufactured and installed at the village. (author)

  10. The origins of disquieting discoveries by Melanie Klein: the possible significance of the case of 'Erna'.

    Science.gov (United States)

    Frank, C; Weiss, H

    1996-12-01

    Using the example of the analysis of 6-year-old Erna, which extended over more than two years and was the longest treatment conducted by Melanie Klein in her Berlin years, the authors demonstrate the importance of her early child analyses for the development of some of her concepts and hence for a decisive advance in psychoanalysis itself. For this purpose they adduce unpublished original documents found among Klein's papers in London, which include autobiographical material, the text of her Würzburg lecture on her obsessional-neurotic little patient, handwritten session notes, and drawings by Erna herself. Although in the author's view Klein attempted to accommodate her findings within Freud's theoretical framework, her clinical experience of the psychic reality of the relational world of early oedipality eventually called for the introduction of new concepts. The combined parent figure, primary sadism, the paranoid-schizoid position, splitting, the relevance of the death drive to the superego, and later formulations on reparation, envy and gratitude are all shown to be foreshadowed in Klein's account of the treatment of Erna. After some retrospective considerations of Erna's analysis and a fleeting glimpse of Erna as an adult, the authors conclude by emphasising the significance of Klein's emigration to England for the subsequent flowering of her work.

  11. Lacan Leitor de Melanie Klein: O Caso Dick em Questão

    Directory of Open Access Journals (Sweden)

    Ariana Lucero

    Full Text Available RESUMO O artigo apresenta a leitura que Jacques Lacan faz do caso Dick, de Melanie Klein. Para tanto, a discussão com o filósofo Jean Hyppolite é retomada com o objetivo de explicitarmos como os mecanismos de Ausstossung [expulsão], Verneinung [negação] e Bejahung [afirmação], descritos por Freud em 1925, podem contribuir para a compreensão da constituição psíquica sob uma perspectiva lacaniana. Em seguida, expomos o caso, tanto para apreendermos clinicamente o que foi exposto na teoria, quanto para evidenciarmos como Lacan se distancia da concepção de fantasia de M. Klein. O tema do diagnóstico, no entanto, aparece em ambos ligado a uma forma de organização subjetiva ainda em constituição na infância, o que traz elementos para refletirmos sobre essa questão na atualidade.

  12. Patronage in the dispute over child analysis between Melanie Klein and Anna Freud--1927-1932.

    Science.gov (United States)

    Aguayo, J

    2000-08-01

    The author investigates the role of patrons and advocates for Melanie Klein's clinical ideas at the British Psycho-Analytical Society against the backdrop of her theoretical and technical differences with Anna Freud from 1927 to 1932. He also outlines the development of Klein and Anna Freud's theories and techniques within the nascent discipline of child psychoanalysis. The London and Viennese patrons/advocates contributed to polarising what initially were clinical differences about how to analyse pre-latency and latency-age children and which technical processes might best facilitate successful treatment. While the author speculates that a diversity of motivations and agendas may have driven the London group's support for Klein--personal and politicised enthusiasm (Jones), genuine conviction (Riviere) and attempts at theoretical rapprochement between the London and Vienna schools (Glover)--he also argues that Freud's diagnosis with cancer in 1923 and suspicion of patricidal son-successors necessitated the choice of a female successor with unquestioning loyalty to his doctrines. From 1932, when Klein's clinical authority was established, her first group of English supporters began to splinter, as she went on to become a training analyst, mentor and patron in her own right to a succeeding generation of adherents who defended her views during the Controversial Discussions.

  13. Melanie Klein and Repression: an examination of some unpublished Notes of 1934.

    Science.gov (United States)

    Hinshelwood, R D

    2006-01-01

    Fifteen pages of unpublished Notes were found in the Melanie Klein Archives dating from early 1934, a crucial moment in Klein's development. She was at this time, 1934, moving away from child analysis, whilst also rethinking and revising her allegiance to Karl Abraham's theory of the phases of libidinal development. These Notes, entitled "Early Repression Mechanism," show Klein struggling to develop what became her characteristic theories of the depressive position and the paranoid-schizoid position. Although these Notes are precursors of the paper Klein gave later to the IPA Congress in 1934, they also show the origins of the emphasis she and her followers eventually gave to "splitting" rather than repression. The Notes give us an insight into the way that she worked clinically at the time. We see Klein's confidence develop as she diverged from the classical theories and technique. Her ideas were based on close attention to the detail of her clinical material, rather than attacking theoretical problems directly. The Notes show her method of struggling to her own conclusions, and they offer us a chance to grasp the roots of the subsequent controversy over Kleinian thought.

  14. The excitation of wakefield in plasma by the sequence of electron bunches

    International Nuclear Information System (INIS)

    Onishchenko, I.N.; Balakirev, V.A.; Berezin, A.K.; Fainberg, J.B.; Kiselyov, V.A.; Linnik, A.F.; Sidel'nikov, G.L.; Sotnikov, G.V.; Uskov, V.V.

    1994-01-01

    The theoretical and experimental investigations of wakefield excitation in plasma by the train of bunches were carried out. The dependence of the wakefield amplitude on the number of bunches was considered and the saturation mechanism was determined. (author). 6 refs, 3 figs

  15. Accurate modeling of the hose instability in plasma wakefield accelerators

    Science.gov (United States)

    Mehrling, T. J.; Benedetti, C.; Schroeder, C. B.; Martinez de la Ossa, A.; Osterhoff, J.; Esarey, E.; Leemans, W. P.

    2018-05-01

    Hosing is a major challenge for the applicability of plasma wakefield accelerators and its modeling is therefore of fundamental importance to facilitate future stable and compact plasma-based particle accelerators. In this contribution, we present a new model for the evolution of the plasma centroid, which enables the accurate investigation of the hose instability in the nonlinear blowout regime. It paves the road for more precise and comprehensive studies of hosing, e.g., with drive and witness beams, which were not possible with previous models.

  16. Electron bunch length measurement with a wakefield radiation decelerator

    Directory of Open Access Journals (Sweden)

    Weiwei Li

    2014-03-01

    Full Text Available In this paper, we propose a novel method to measure the electron bunch length with a dielectric wakefield radiation (DWR decelerator which is composed of two dielectric-lined waveguides (DLWs and an electron spectrometer. When an electron beam passes through a DLW, the DWR is excited which leads to an energy loss of the electron beam. The energy loss is found to be largely dependent on the electron bunch length and can be easily measured by an electron spectrometer which is essential for a normal accelerator facility. Our study shows that this method has a high resolution and a great simplicity.

  17. Quasi-stable injection channels in a wakefield accelerator

    CERN Document Server

    Wiltshire-Turkay, Mara; Pukhov, Alexander

    2016-01-01

    Particle-driven plasma-wakefield acceleration is a promising alternative to conventional electron acceleration techniques, potentially allowing electron acceleration to energies orders of magnitude higher than can currently be achieved. In this work we investigate the dependence of the energy gain on the position at which electrons are injected into the wake. Test particle simulations show previously unobserved complex structure in the parameter space, with quasi-stable injection channels forming for particles injected in narrow regions away from the centre of the wake. The result is relevant to the planning and tuning of experiments making use of external injection.

  18. Resistive wall wakefields of short bunches at cryogenic temperatures

    Directory of Open Access Journals (Sweden)

    G. Stupakov

    2015-03-01

    Full Text Available We present calculations of the longitudinal wakefields at cryogenic temperatures for extremely short bunches, characteristic for modern x-ray free electron lasers. The calculations are based on the equations for the surface impedance in the regime of the anomalous skin effect in metals. This paper extends and complements an earlier analysis of B. Podobedov, Phys. Rev. ST Accel. Beams 12, 044401 (2009. into the region of very high frequencies associated with bunch lengths in the micron range. We study in detail the case of a rectangular bunch distribution for parameters of interest of LCLS-II with a superconducting undulator.

  19. Optical plasma torch electron bunch generation in plasma wakefield accelerators

    Directory of Open Access Journals (Sweden)

    G. Wittig

    2015-08-01

    Full Text Available A novel, flexible method of witness electron bunch generation in plasma wakefield accelerators is described. A quasistationary plasma region is ignited by a focused laser pulse prior to the arrival of the plasma wave. This localized, shapeable optical plasma torch causes a strong distortion of the plasma blowout during passage of the electron driver bunch, leading to collective alteration of plasma electron trajectories and to controlled injection. This optically steered injection is more flexible and faster when compared to hydrodynamically controlled gas density transition injection methods.

  20. Photonuclear fission with quasimonoenergetic electron beams from laser wakefields

    International Nuclear Information System (INIS)

    Reed, S. A.; Chvykov, V.; Kalintchenko, G.; Matsuoka, T.; Rousseau, P.; Yanovsky, V.; Vane, C. R.; Beene, J. R.; Stracener, D.; Schultz, D. R.; Maksimchuk, A.

    2006-01-01

    Recent advancements in laser wakefield accelerators have resulted in the generation of low divergence, hundred MeV, quasimonoenergetic electron beams. The bremsstrahlung produced by these highly energetic electrons in heavy converters includes a large number of MeV γ rays that have been utilized to induce photofission in natural uranium. Analysis of the measured delayed γ emission demonstrates production of greater than 3x10 5 fission events per joule of laser energy, which is more than an order of magnitude greater than that previously achieved. Monte Carlo simulations model the generated bremsstrahlung spectrum and compare photofission yields as a function of target depth and incident electron energy

  1. A proof of principle experiment of laser wakefield accelerator

    International Nuclear Information System (INIS)

    Nakajima, K.; Enomoto, A.; Nakanishi, H.; Ogata, A.; Kato, Y.; Kitagawa, Y.; Mima, K.; Shiraga, H.; Yamakawa, K.; Downer, M.; Horton, W.; Newberger, B.; Tajima, T.

    1992-01-01

    Ultrashort super-intense lasers allow us to test a principle of the laser wakefield particle acceleration. The peak power of 30 TW and the pulse width of 1 ps produced by the Nd:glass laser system is capable of creating a highly-ionized plasma of a moderate density gas in an ultrafast time scale and generating a large amplitude plasma wave with the accelerating gradient of 2.5 GeV/m. Particle acceleration can be demonstrated by injecting a few MeV electrons emitted from a solid target by intense laser irradiation. (Author) 2 figs., 5 refs

  2. Rezension zu: Julia Kristeva: Das weibliche Genie – Melanie Klein. Gießen: Psychosozial-Verlag 2008

    Directory of Open Access Journals (Sweden)

    Lilli Gast

    2009-07-01

    Full Text Available Julia Kristeva widmet sich im zweiten Teil ihrer Trilogie über das weibliche Genie dem Leben und Werk von Melanie Klein, die mit ihren Arbeiten über die früheste Verfasstheit des Psychischen das psychoanalytische Denken für die Psychosen und den Wahn aufschloss und die Rolle des Mütterlichen im psychoanalytischen Diskurs neu definierte. In ihrer Auseinandersetzung mit Klein gelingt Kristeva nicht nur eine ausgesprochen gelungene Einführung in Kleins Denken, sondern auch eine Analyse weiblicher Intellektualität im 20. Jahrhundert. Zudem werden die Schnittstellen im Denken Kleins und Kristevas sichtbar.

  3. Wakefield damping in a pair of X-band accelerators for linear colliders

    Directory of Open Access Journals (Sweden)

    Roger M. Jones

    2006-10-01

    Full Text Available We consider the means to damp the wakefield left behind ultrarelativistic charges. In particular, we focus on a pair of traveling wave accelerators operating at an X-band frequency of 11.424 GHz. In order to maximize the efficiency of acceleration, in the context of a linear collider, multiple bunches of charged particles are accelerated within a given pulse of the electromagnetic field. The wakefield left behind successive bunches, if left unchecked, can seriously disturb the progress of trailing bunches and can lead to an appreciable dilution in the emittance of the beam. We report on a method to minimize the influence of the wakefield on trailing bunches. This method entails detuning the characteristic mode frequencies which make up the electromagnetic field, damping the wakefield, and interleaving the frequencies of adjacent accelerating structures. Theoretical predictions of the wakefield and modes, based on a circuit model, are compared with experimental measurements of the wakefield conducted within the ASSET facility at SLAC. Very good agreement is obtained between theory and experiment and this allows us to have some confidence in designing the damping of wakefields in a future linear collider consisting of several thousand of these accelerating structures.

  4. Wakefield Damping in a Pair of X-Band Accelerators for Linear Colliders

    International Nuclear Information System (INIS)

    Jones, R.M.; Adolphsen, C.E.; Wang, J.W.; Li, Z.; SLAC

    2006-01-01

    We consider means to damp the wake-field left behind ultra-relativistic charges. In particular, we focus on a pair of travelling wave accelerators operating at an X-band frequency of 11.424 GHz. In order to maximize the efficiency of acceleration, in the context of a linear collider, multiple bunches of charged particles are accelerated within a given pulse of the electromagnetic field. The wake-field left behind successive bunches, if left unchecked, can seriously disturb the progress of trailing bunches and can lead to an appreciable dilution in the emittance of the beam. We report on a method to minimize the influence of the wake-field on trailing bunches. This method entails detuning the characteristic mode frequencies which make-up the electromagnetic field, damping the wake-field, and interleaving the frequencies of adjacent accelerating structures. Theoretical predictions of the wake-field and modes, based on a circuit model, are compared with experimental measurements of the wake-field conducted within the ASSET facility at SLAC. Very good agreement is obtained between theory and experiment and this allows us to have some confidence in designing the damping of wake-fields in a future linear collider consisting of several thousand of these accelerating structures

  5. Beyond injection: Trojan horse underdense photocathode plasma wakefield acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Hidding, B.; Rosenzweig, J. B.; Xi, Y.; O' Shea, B.; Andonian, G.; Schiller, D.; Barber, S.; Williams, O.; Pretzler, G.; Koenigstein, T.; Kleeschulte, F.; Hogan, M. J.; Litos, M.; Corde, S.; White, W. W.; Muggli, P.; Bruhwiler, D. L.; Lotov, K. [Institut fuer Laser- und Plasmaphysik, Heinrich-Heine-Universitaet Duesseldorf 40225 Duesseldorf (Germany) and Particle Beam Physics Laboratory, Department for Physics and Astronomy, UCLA (United States); Particle Beam Physics Laboratory, Department for Physics and Astronomy, UCLA (United States); Institut fuer Laser- und Plasmaphysik, Heinrich-Heine-Universitaet Duesseldorf 40225 Duesseldorf (Germany); Stanford Linear Accelerator Center (United States); Max-Planck-Institut fuer Physik, Muenchen (Germany); Tech-X Corporation, Boulder, Colorado (United States) and 1348 Redwood Ave., Boulder, Colorado 80304 (United States); Budker Institute of Nuclear Physics SB RAS, 630090, Novosibirsk (Russian Federation) and Novosibirsk State University, 630090, Novosibirsk (Russian Federation)

    2012-12-21

    An overview on the underlying principles of the hybrid plasma wakefield acceleration scheme dubbed 'Trojan Horse' acceleration is given. The concept is based on laser-controlled release of electrons directly into a particle-beam-driven plasma blowout, paving the way for controlled, shapeable electron bunches with ultralow emittance and ultrahigh brightness. Combining the virtues of a low-ionization-threshold underdense photocathode with the GV/m-scale electric fields of a practically dephasing-free beam-driven plasma blowout, this constitutes a 4th generation electron acceleration scheme. It is applicable as a beam brightness transformer for electron bunches from LWFA and PWFA systems alike. At FACET, the proof-of-concept experiment 'E-210: Trojan Horse Plasma Wakefield Acceleration' has recently been approved and is in preparation. At the same time, various LWFA facilities are currently considered to host experiments aiming at stabilizing and boosting the electron bunch output quality via a trojan horse afterburner stage. Since normalized emittance and brightness can be improved by many orders of magnitude, the scheme is an ideal candidate for light sources such as free-electron-lasers and those based on Thomson scattering and betatron radiation alike.

  6. Increasing the transformer ratio at the Argonne wakefield accelerator

    International Nuclear Information System (INIS)

    Power, J.G.; Conde, M.; Liu, W.; Yusof, Z.; Gai, W.; Jing, C.; Kanareykin, A.

    2011-01-01

    The transformer ratio is defined as the ratio of the maximum energy gain of the witness bunch to the maximum energy loss experienced by the drive bunch (or a bunch within a multidrive bunch train). This plays an important role in the collinear wakefield acceleration scheme. A high transformer ratio is desirable since it leads to a higher overall efficiency under similar conditions (e.g. the same beam loading, the same structure, etc.). One technique to enhance the transformer ratio beyond the ordinary limit of 2 is to use a ramped bunch train. The first experimental demonstration observed a transformer ratio only marginally above 2 due to the mismatch between the drive microbunch length and the frequency of the accelerating structure (C. Jing, A. Kanareykin, J. Power, M. Conde, Z. Yusof, P. Schoessow, and W. Gai, Phys. Rev. Lett. 98, 144801 (2007)). Recently, we revisited this experiment with an optimized microbunch length using a UV laser stacking technique at the Argonne Wakefield Accelerator facility and measured a transformer ratio of 3.4. Measurements and data analysis from these experiments are presented in detail.

  7. Transverse emittance growth in staged laser-wakefield acceleration

    Directory of Open Access Journals (Sweden)

    T. Mehrling

    2012-11-01

    Full Text Available We present a study on the emittance evolution of electron bunches, externally injected into laser-driven plasma waves using the three-dimensional particle-in-cell (PIC code OSIRIS. Results show order-of-magnitude transverse emittance growth during the injection process, if the electron bunch is not matched to its intrinsic betatron motion inside the wakefield. This behavior is supported by analytic theory reproducing the simulation data to a percent level. The length over which the full emittance growth develops is found to be less than or comparable to the typical dimension of a single plasma module in current multistage designs. In addition, the analytic theory enables the quantitative prediction of emittance degradation in two consecutive accelerators coupled by free-drift sections, excluding this as a scheme for effective emittance-growth suppression, and thus suggests the necessity of beam-matching sections between acceleration stages with fundamental implications on the overall design of staged laser-wakefield accelerators.

  8. A Proton-Driven Plasma Wakefield Acceleration experiment at CERN

    CERN Multimedia

    The AWAKE Collaboration has been formed in order to demonstrate protondriven plasma wakefield acceleration for the first time. This technology could lead to future colliders of high energy but of a much reduced length compared to proposed linear accelerators. The SPS proton beam in the CNGS facility will be injected into a 10m plasma cell where the long proton bunches will be modulated into significantly shorter micro-bunches. These micro-bunches will then initiate a strong wakefield in the plasma with peak fields above 1 GV/m that will be harnessed to accelerate a bunch of electrons from about 20MeV to the GeV scale within a few meters. The experimental program is based on detailed numerical simulations of beam and plasma interactions. The main accelerator components, the experimental area and infrastructure required as well as the plasma cell and the diagnostic equipment are discussed in detail. First protons to the experiment are expected at the end of 2016 and this will be followed by an initial 3–4 yea...

  9. Instant OpenCV starter

    CERN Document Server

    Dalal, Jayneil

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks.A practical, quick, and hands-on guide for Python developers and hobbyists who want to get started with computer vision with OpenCV.This book is great for developers, hobbyists, and students new to computer vision who are looking to get a good grounding in how to use the OpenCV library. It's assumed that you will have some basic experience in C/C++ programming.

  10. A fast way for calculating longitudinal wakefields for high Q resonances

    International Nuclear Information System (INIS)

    Cheng-Yang Tan and James M Steimel

    2001-01-01

    We have come up with a way for calculating longitudinal wakefields for high Q resonances by mapping the wake functions to a two dimension vector space. Then in this space, a transformation which is basically a scale change and a rotation, allows us to calculate the new wakefield by knowing only one previous wakefield and one previous particle passage through the cavity. We will also compare this method to the brute force method which needs to know all the passages of the previous particles through the cavity

  11. Experiments on resonator concept of plasma wakefield accelerator driven by a train of relativistic electron bunches

    International Nuclear Information System (INIS)

    Kiselev, V.A.; Linnik, A.F.; Mirny, V. I; Onishchenko, I.N.; Uskov, V.V.

    2008-01-01

    The experimental installation was elaborated to increase plasma wakefield amplitude by means of using plasma resonator that allows all bunches of the train to participate in wakefield build-up contrary to waveguide case, in which due to group velocity effect only a part of the bunches participates. Experiments on plasma producing with resonant density, at which a coincidence of the plasma frequency and bunch repetition frequency is provided, are carried out. The first results of the measurements of beam energy loss on plasma wakefield excitation and energy gain by accelerated electrons are presented

  12. Wakefield excitation in plasma resonator by a sequence of relativistic electron bunches

    International Nuclear Information System (INIS)

    Kiselev, V.A.; Linnik, A.F.; Mirny, V.I.; Onishchenko, I.N.; Uskov, V.V.

    2008-01-01

    Wakefield excitation in a plasma resonator by a sequence of relativistic electron bunches with the purpose to increase excited field amplitude in comparison to waveguide case is experimentally investigated. A sequence of short electron bunches is produced by the linear resonant accelerator. Plasma resonator is formed at the beam-plasma discharge in rectangular metal waveguide filled with gas and closed by metal foil at entrance and movable short-circuited plunger at exit. Measurements of wakefield amplitude are performed showing considerably higher wakefield amplitude for resonator case

  13. AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

    CERN Document Server

    Gschwendtner, E.; Amorim, L.; Apsimon, R.; Assmann, R.; Bachmann, A.M.; Batsch, F.; Bauche, J.; Berglyd Olsen, V.K.; Bernardini, M.; Bingham, R.; Biskup, B.; Bohl, T.; Bracco, C.; Burrows, P.N.; Burt, G.; Buttenschon, B.; Butterworth, A.; Caldwell, A.; Cascella, M.; Chevallay, E.; Cipiccia, S.; Damerau, H.; Deacon, L.; Dirksen, P.; Doebert, S.; Dorda, U.; Farmer, J.; Fedosseev, V.; Feldbaumer, E.; Fiorito, R.; Fonseca, R.; Friebel, F.; Gorn, A.A.; Grulke, O.; Hansen, J.; Hessler, C.; Hofle, W.; Holloway, J.; Huther, M.; Jaroszynski, D.; Jensen, L.; Jolly, S.; Joulaei, A.; Kasim, M.; Keeble, F.; Li, Y.; Liu, S.; Lopes, N.; Lotov, K.V.; Mandry, S.; Martorelli, R.; Martyanov, M.; Mazzoni, S.; Mete, O.; Minakov, V.A.; Mitchell, J.; Moody, J.; Muggli, P.; Najmudin, Z.; Norreys, P.; Oz, E.; Pardons, A.; Pepitone, K.; Petrenko, A.; Plyushchev, G.; Pukhov, A.; Rieger, K.; Ruhl, H.; Salveter, F.; Savard, N.; Schmidt, J.; Seryi, A.; Shaposhnikova, E.; Sheng, Z.M.; Sherwood, P.; Silva, L.; Soby, L.; Sosedkin, A.P.; Spitsyn, R.I.; Trines, R.; Tuev, P.V.; Turner, M.; Verzilov, V.; Vieira, J.; Vincke, H.; Wei, Y.; Welsch, C.P.; Wing, M.; Xia, G.; Zhang, H.

    2016-01-01

    The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms ~12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (~15 MeV) electrons will be externally injected to sample the wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

  14. Plasma Wakefield Acceleration of an Intense Positron Beam

    Energy Technology Data Exchange (ETDEWEB)

    Blue, B

    2004-04-21

    The Plasma Wakefield Accelerator (PWFA) is an advanced accelerator concept which possess a high acceleration gradient and a long interaction length for accelerating both electrons and positrons. Although electron beam-plasma interactions have been extensively studied in connection with the PWFA, very little work has been done with respect to positron beam-plasma interactions. This dissertation addresses three issues relating to a positron beam driven plasma wakefield accelerator. These issues are (a) the suitability of employing a positron drive bunch to excite a wake; (b) the transverse stability of the drive bunch; and (c) the acceleration of positrons by the plasma wake that is driven by a positron bunch. These three issues are explored first through computer simulations and then through experiments. First, a theory is developed on the impulse response of plasma to a short drive beam which is valid for small perturbations to the plasma density. This is followed up with several particle-in-cell (PIC) simulations which study the experimental parameter (bunch length, charge, radius, and plasma density) range. Next, the experimental setup is described with an emphasis on the equipment used to measure the longitudinal energy variations of the positron beam. Then, the transverse dynamics of a positron beam in a plasma are described. Special attention is given to the way focusing, defocusing, and a tilted beam would appear to be energy variations as viewed on our diagnostics. Finally, the energy dynamics imparted on a 730 {micro}m long, 40 {micro}m radius, 28.5 GeV positron beam with 1.2 x 10{sup 10} particles in a 1.4 meter long 0-2 x 10{sup 14} e{sup -}/cm{sup 3} plasma is described. First the energy loss was measured as a function of plasma density and the measurements are compared to theory. Then, an energy gain of 79 {+-} 15 MeV is shown. This is the first demonstration of energy gain of a positron beam in a plasma and it is in good agreement with the predictions

  15. RF power generation and coupling measurements for the dielectric wakefield step-up transformer

    International Nuclear Information System (INIS)

    Conde, M. E.

    1998-01-01

    The dielectric wakefield transformer (DWT) is one route to practical high energy wakefield-based accelerators. Progress has been made in a number of areas relevant to the demonstration of this device. In this article we describe recent bench measurements and beam experiments using 7.8 and 15.6 GHz structures and discuss some remaining technical challenges in the development of the DWT

  16. Electron self-injection in the donut bubble wakefield

    Science.gov (United States)

    Firouzjaei, Ali Shekari; Shokri, Babak

    2018-05-01

    We investigate electron self-injection in a donut bubble wakefield driven by a Laguerre-Gauss laser pulse. The present work discusses the electron capture by modeling the analytical donut bubble field. We discuss the self-injection of the electrons from plasma for various initial conditions and then compare the results. We show that the donut bubble can trap plasma electrons forming a hollow beam. We present the phase spaces and longitudinal momentum evolution for the trapped electrons in the bubble and discuss their characteristic behaviors and stability. It will be shown that the electrons self-injected in the front are ideal for applications in which a good stability and low energy spread are essential.

  17. Wake-field generation by the ponderomotive memory effect

    International Nuclear Information System (INIS)

    Wolf, U.; Schamel, H.

    1997-01-01

    An analytical and numerical investigation of the plasma response to an imposed high frequency wave packet with a slow explicit time-dependent envelope is presented. An underlying picture of ponderomotive effects is developed, which shows that the explicit time dependence forces us to treat the problem kinetically, and furthermore, that a wake field is generated by the ponderomotive memory effect. The latter supplements the well-known ponderomotive force and fake heating effect. Several perturbation schemes are compared showing that the influence of resonant particles, treated by the method of characteristics, has to be taken into account for Langmuir wave packets with kλ d ≥0.2, where k is the wave number and λ d the Debye length. A self-consistent Vlasov simulation shows the disappearance of the density depression in the case of immobile ions, whereas the wake-field pattern survives self-consistency. copyright 1997 The American Physical Society

  18. Gamma-neutron activation experiments using laser wakefield accelerators

    International Nuclear Information System (INIS)

    Leemans, W.P.; Rodgers, D.; Catravas, P.E.; Geddes, C.G.R.; Fubiani, G.; Esarey, E.; Shadwick, B.A.; Donahue, R.; Smith, A.

    2001-01-01

    Gamma-neutron activation experiments have been performed with relativistic electron beams produced by a laser wakefield accelerator. The electron beams were produced by tightly focusing (spot diameter ≅6 μm) a high power (up to 10 TW), ultra-short (≥50 fs) laser beam from a high repetition rate (10 Hz) Ti:sapphire (0.8 μm) laser system, onto a high density (>10 19 cm -3 ) pulsed gasjet of length ≅1.5 mm. Nuclear activation measurements in lead and copper targets indicate the production of electrons with energy in excess of 25 MeV. This result was confirmed by electron distribution measurements using a bending magnet spectrometer. Measured γ-ray and neutron yields are also found to be in reasonable agreement with simulations using a Monte Carlo transport code

  19. First results of the plasma wakefield acceleration experiment at PITZ

    International Nuclear Information System (INIS)

    Lishilin, O.; Gross, M.; Brinkmann, R.; Engel, J.; Grüner, F.; Koss, G.; Krasilnikov, M.; Martinez de la Ossa, A.; Mehrling, T.; Osterhoff, J.; Pathak, G.; Philipp, S.; Renier, Y.; Richter, D.; Schroeder, C.; Schütze, R.; Stephan, F.

    2016-01-01

    The self-modulation instability of long particle beams was proposed as a new mechanism to produce driver beams for proton driven plasma wakefield acceleration (PWFA). The PWFA experiment at the Photo Injector Test facility at DESY, Zeuthen site (PITZ) was launched to experimentally demonstrate and study the self-modulation of long electron beams in plasma. Key aspects for the experiment are the very flexible photocathode laser system, a plasma cell and well-developed beam diagnostics. In this contribution we report about the plasma cell design, preparatory experiments and the results of the first PWFA experiment at PITZ. - Highlights: • A self-modulation mechanism for producing driver beams for PWFA is proposed. • A proof-of-principle experiment is launched at the Photo Injector Test facility at DESY. • The self-modulation instability occurs in long particle beams passing through plasma. • A heat pipe oven and a laser are used to produce plasma.

  20. Laser wakefield acceleration using wire produced double density ramps

    Directory of Open Access Journals (Sweden)

    M. Burza

    2013-01-01

    Full Text Available A novel approach to implement and control electron injection into the accelerating phase of a laser wakefield accelerator is presented. It utilizes a wire, which is introduced into the flow of a supersonic gas jet creating shock waves and three regions of differing plasma electron density. If tailored appropriately, the laser plasma interaction takes place in three stages: Laser self-compression, electron injection, and acceleration in the second plasma wave period. Compared to self-injection by wave breaking of a nonlinear plasma wave in a constant density plasma, this scheme increases beam charge by up to 1 order of magnitude in the quasimonoenergetic regime. Electron acceleration in the second plasma wave period reduces electron beam divergence by ≈25%, and the localized injection at the density downramps results in spectra with less than a few percent relative spread.

  1. Preformed transient gas channels for laser wakefield particle acceleration

    International Nuclear Information System (INIS)

    Wood, W.M.

    1994-01-01

    Acceleration of electrons by laser-driven plasma wake fields is limited by the range over which a laser pulse can maintain its intensity. This distance is typically given by the Rayleigh range for the focused laser beam, usually on the order of 0.1 mm to 1 mm. For practical particle acceleration, interaction distances on the order of centimeters are required. Therefore, some means of guiding high intensity laser pulses is necessary. Light intensities on the order of a few times 10 17 W/cm 2 are required for laser wakefield acceleration schemes using near IR radiation. Gas densities on the order of or greater than 10 17 cm -3 are also needed. Laser-atom interaction studies in this density and intensity regime are generally limited by the concomitant problems in beam propagation introduced by the creation of a plasma. In addition to the interaction distance limit imposed by the Rayleigh range, defocusing of the high intensity laser pulse further limits the peak intensity which can be achieved. To solve the problem of beam propagation limitations in laser-plasma wakefield experiments, two potential methods for creating transient propagation channels in gaseous targets are investigated. The first involves creation of a charge-neutral channel in a gas by an initial laser pulse, which then is ionized by a second, ultrashort, high-intensity pulse to create a waveguide. The second method involves the ionization of a gas column by an ultrashort pulse; a transient waveguide is formed by the subsequent expansion of the heated plasma into the neutral gas

  2. Theory and measurements of emittance preservation in plasma wakefield acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Frederico, Joel

    2016-12-01

    In this dissertation, we examine the preservation and measurement of emittance in the plasma wakefield acceleration blowout regime. Plasma wakefield acceleration (PWFA) is a revolutionary approach to accelerating charged particles that has been demonstrated to have the potential for gradients orders of magnitude greater than traditional approaches. The application of PWFA to the design of a linear collider will make new high energy physics research possible, but the design parameters must first be shown to be competitive with traditional methods. Emittance preservation is necessary in the design of a linear collider in order to maximize luminosity. We examine the conditions necessary for circular symmetry in the PWFA blowout regime, and demonstrate that current proposals meet these bounds. We also present an application of beam lamentation which describes the process of beam parameter and emittance matching. We show that the emittance growth saturates as a consequence of energy spread in the beam. The initial beam parameters determine the amount of emittance growth, while the contribution of energy spread is negligible. We also present a model for ion motion in the presence of a beam that is much more dense than the plasma. By combining the model of ion motion and emittance growth, we find the emittance growth due to ion motion is minimal in the case of marginal ion motion. In addition, we present a simulation that validates the ion motion model, which is under further development to examine emittance growth of both marginal and pronounced ion motion. Finally, we present a proof-of-concept of an emittance measurement which may enable the analysis of emittance preservation in future PWFA experiments.

  3. Melanie II--a third-generation software package for analysis of two-dimensional electrophoresis images: II. Algorithms.

    Science.gov (United States)

    Appel, R D; Vargas, J R; Palagi, P M; Walther, D; Hochstrasser, D F

    1997-12-01

    After two generations of software systems for the analysis of two-dimensional electrophoresis (2-DE) images, a third generation of such software packages has recently emerged that combines state-of-the-art graphical user interfaces with comprehensive spot data analysis capabilities. A key characteristic common to most of these software packages is that many of their tools are implementations of algorithms that resulted from research areas such as image processing, vision, artificial intelligence or machine learning. This article presents the main algorithms implemented in the Melanie II 2-D PAGE software package. The applications of these algorithms, embodied as the feature of the program, are explained in an accompanying article (R. D. Appel et al.; Electrophoresis 1997, 18, 2724-2734).

  4. Particle-in-cell simulation of x-ray wakefield acceleration and betatron radiation in nanotubes

    Directory of Open Access Journals (Sweden)

    Xiaomei Zhang

    2016-10-01

    Full Text Available Though wakefield acceleration in crystal channels has been previously proposed, x-ray wakefield acceleration has only recently become a realistic possibility since the invention of the single-cycled optical laser compression technique. We investigate the acceleration due to a wakefield induced by a coherent, ultrashort x-ray pulse guided by a nanoscale channel inside a solid material. By two-dimensional particle-in-cell computer simulations, we show that an acceleration gradient of TeV/cm is attainable. This is about 3 orders of magnitude stronger than that of the conventional plasma-based wakefield accelerations, which implies the possibility of an extremely compact scheme to attain ultrahigh energies. In addition to particle acceleration, this scheme can also induce the emission of high energy photons at ∼O(10–100  MeV. Our simulations confirm such high energy photon emissions, which is in contrast with that induced by the optical laser driven wakefield scheme. In addition to this, the significantly improved emittance of the energetic electrons has been discussed.

  5. Plasma Density Tapering for Laser Wakefield Acceleration of Electrons and Protons

    International Nuclear Information System (INIS)

    Ting, A.; Gordon, D.; Kaganovich, D.; Sprangle, P.; Helle, M.; Hafizi, B.

    2010-01-01

    Extended acceleration in a Laser Wakefield Accelerator can be achieved by tailoring the phase velocity of the accelerating plasma wave, either through profiling of the density of the plasma or direct manipulation of the phase velocity. Laser wakefield acceleration has also reached a maturity that proton acceleration by wakefield could be entertained provided we begin with protons that are substantially relativistic, ∼1 GeV. Several plasma density tapering schemes are discussed. The first scheme is called ''bucket jumping'' where the plasma density is abruptly returned to the original density after a conventional tapering to move the accelerating particles to a neighboring wakefield period (bucket). The second scheme is designed to specifically accelerate low energy protons by generating a nonlinear wakefield in a plasma region with close to critical density. The third scheme creates a periodic variation in the phase velocity by beating two intense laser beams with laser frequency difference equal to the plasma frequency. Discussions and case examples with simulations are presented where substantial acceleration of electrons or protons could be obtained.

  6. Automatic Beam Path Analysis of Laser Wakefield Particle Acceleration Data

    Energy Technology Data Exchange (ETDEWEB)

    Rubel, Oliver; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Wu, Kesheng; Prabhat,; Weber, Gunther H.; Ushizima, Daniela M.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes

    2009-10-19

    Numerical simulations of laser wakefield particle accelerators play a key role in the understanding of the complex acceleration process and in the design of expensive experimental facilities. As the size and complexity of simulation output grows, an increasingly acute challenge is the practical need for computational techniques that aid in scientific knowledge discovery. To that end, we present a set of data-understanding algorithms that work in concert in a pipeline fashion to automatically locate and analyze high energy particle bunches undergoing acceleration in very large simulation datasets. These techniques work cooperatively by first identifying features of interest in individual timesteps, then integrating features across timesteps, and based on the information derived perform analysis of temporally dynamic features. This combination of techniques supports accurate detection of particle beams enabling a deeper level of scientific understanding of physical phenomena than hasbeen possible before. By combining efficient data analysis algorithms and state-of-the-art data management we enable high-performance analysis of extremely large particle datasets in 3D. We demonstrate the usefulness of our methods for a variety of 2D and 3D datasets and discuss the performance of our analysis pipeline.

  7. Automated analysis for detecting beams in laser wakefield simulations

    International Nuclear Information System (INIS)

    Ushizima, Daniela M.; Rubel, Oliver; Prabhat, Mr.; Weber, Gunther H.; Bethel, E. Wes; Aragon, Cecilia R.; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Hamann, Bernd; Messmer, Peter; Hagen, Hans

    2008-01-01

    Laser wakefield particle accelerators have shown the potential to generate electric fields thousands of times higher than those of conventional accelerators. The resulting extremely short particle acceleration distance could yield a potential new compact source of energetic electrons and radiation, with wide applications from medicine to physics. Physicists investigate laser-plasma internal dynamics by running particle-in-cell simulations; however, this generates a large dataset that requires time-consuming, manual inspection by experts in order to detect key features such as beam formation. This paper describes a framework to automate the data analysis and classification of simulation data. First, we propose a new method to identify locations with high density of particles in the space-time domain, based on maximum extremum point detection on the particle distribution. We analyze high density electron regions using a lifetime diagram by organizing and pruning the maximum extrema as nodes in a minimum spanning tree. Second, we partition the multivariate data using fuzzy clustering to detect time steps in a experiment that may contain a high quality electron beam. Finally, we combine results from fuzzy clustering and bunch lifetime analysis to estimate spatially confined beams. We demonstrate our algorithms successfully on four different simulation datasets

  8. Compact and tunable focusing device for plasma wakefield acceleration

    Science.gov (United States)

    Pompili, R.; Anania, M. P.; Chiadroni, E.; Cianchi, A.; Ferrario, M.; Lollo, V.; Notargiacomo, A.; Picardi, L.; Ronsivalle, C.; Rosenzweig, J. B.; Shpakov, V.; Vannozzi, A.

    2018-03-01

    Plasma wakefield acceleration, either driven by ultra-short laser pulses or electron bunches, represents one of the most promising techniques able to overcome the limits of conventional RF technology and allows the development of compact accelerators. In the particle beam-driven scenario, ultra-short bunches with tiny spot sizes are required to enhance the accelerating gradient and preserve the emittance and energy spread of the accelerated bunch. To achieve such tight transverse beam sizes, a focusing system with short focal length is mandatory. Here we discuss the development of a compact and tunable system consisting of three small-bore permanent-magnet quadrupoles with 520 T/m field gradient. The device has been designed in view of the plasma acceleration experiments planned at the SPARC_LAB test-facility. Being the field gradient fixed, the focusing is adjusted by tuning the relative position of the three magnets with nanometer resolution. Details about its magnetic design, beam-dynamics simulations, and preliminary results are examined in the paper.

  9. High quality electron beams from a laser wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Wiggins, S M; Issac, R C; Welsh, G H; Brunetti, E; Shanks, R P; Anania, M P; Cipiccia, S; Manahan, G G; Aniculaesei, C; Ersfeld, B; Islam, M R; Burgess, R T L; Vieux, G; Jaroszynski, D A [SUPA, Department of Physics, University of Strathclyde, Glasgow (United Kingdom); Gillespie, W A [SUPA, Division of Electronic Engineering and Physics, University of Dundee, Dundee (United Kingdom); MacLeod, A M [School of Computing and Creative Technologies, University of Abertay Dundee, Dundee (United Kingdom); Van der Geer, S B; De Loos, M J, E-mail: m.wiggins@phys.strath.ac.u [Pulsar Physics, Burghstraat 47, 5614 BC Eindhoven (Netherlands)

    2010-12-15

    High quality electron beams have been produced in a laser-plasma accelerator driven by femtosecond laser pulses with a peak power of 26 TW. Electrons are produced with an energy up to 150 MeV from the 2 mm gas jet accelerator and the measured rms relative energy spread is less than 1%. Shot-to-shot stability in the central energy is 3%. Pepper-pot measurements have shown that the normalized transverse emittance is {approx}1{pi} mm mrad while the beam charge is in the range 2-10 pC. The generation of high quality electron beams is understood from simulations accounting for beam loading of the wakefield accelerating structure. Experiments and self-consistent simulations indicate that the beam peak current is several kiloamperes. Efficient transportation of the beam through an undulator is simulated and progress is being made towards the realization of a compact, high peak brilliance free-electron laser operating in the vacuum ultraviolet and soft x-ray wavelength ranges.

  10. Detection of inverse Compton scattering in plasma wakefield experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bohlen, Simon

    2016-12-15

    Inverse Compton scattering (ICS) is the process of scattering of photons and electrons, where the photons gain a part of the electrons energy. In combination with plasma wakefield acceleration (PWA), ICS offers a compact MeV γ-ray source. A numerical study of ICS radiation produced in PWA experiments at FLASHForward was performed, using an ICS simulation code and the results from particle-in-cell modelling. The possibility of determining electron beam properties from measurements of the γ-ray source was explored for a wide range of experimental conditions. It was found that information about the electron divergence, the electron spectrum and longitudinal information can be obtained from measurements of the ICS beams for some cases. For the measurement of the ICS profile at FLASHForward, a CsI(Tl) scintillator array was chosen, similar to scintillators used in other ICS experiments. To find a suitable detector for spectrum measurements, an experimental test of a Compton spectrometer at the RAL was conducted. This test showed that a similar spectrometer could also be used at FLASHForward. However, changes to the spectrometer could be needed in order to use the pair production effect. In addition, further studies using Geant4 could lead to a better reconstruction of the obtained data. The studies presented here show that ICS is a promising method to analyse electron parameters from PWA experiments in further detail.

  11. Experimental Characterization of Electron-Beam-Driven Wakefield Modes in a Dielectric-Woodpile Cartesian Symmetric Structure

    Science.gov (United States)

    Hoang, P. D.; Andonian, G.; Gadjev, I.; Naranjo, B.; Sakai, Y.; Sudar, N.; Williams, O.; Fedurin, M.; Kusche, K.; Swinson, C.; Zhang, P.; Rosenzweig, J. B.

    2018-04-01

    Photonic structures operating in the terahertz (THz) spectral region enable the essential characteristics of confinement, modal control, and electric field shielding for very high gradient accelerators based on wakefields in dielectrics. We report here an experimental investigation of THz wakefield modes in a three-dimensional photonic woodpile structure. Selective control in exciting or suppressing of wakefield modes with a nonzero transverse wave vector is demonstrated by using drive beams of varying transverse ellipticity. Additionally, we show that the wakefield spectrum is insensitive to the offset position of strongly elliptical beams. These results are consistent with analytic theory and three-dimensional simulations and illustrate a key advantage of wakefield systems with Cartesian symmetry: the suppression of transverse wakes by elliptical beams.

  12. Electron Acceleration in Wakefield and Supra-Bubble Regimes by Ultraintense Laser with Asymmetric Pulse

    International Nuclear Information System (INIS)

    Maimaitiaili, Bake; Sayipjamal, Dulat; Aimierding, Aimidula; Xie Baisong

    2011-01-01

    Electron acceleration in plasma driven by circular polarized ultraintense laser with asymmetric pulse are investigated analytically and numerically in terms of oscillation-center Hamiltonian formalism. Studies include wakefield acceleration, which dominates in blow-out or bubble regime and snow-plow acceleration which dominates in supra-bubble regime. By a comparison with each other it is found that snow-plow acceleration has lower acceleration capability. In wakefield acceleration, there exists an obvious optimum pulse asymmetry or/and pulse lengths that leads to the high net energy gain while in snow-plow acceleration it is insensitive to the pulse lengths. Power and linear scaling laws for wakefield and snow-plow acceleration respetively are observed from the net energy gain depending on laser field amplitude. Moreover, there exists also an upper and lower limit on plasma density for an effective acceleration in both of regimes. (physics of gases, plasmas, and electric discharges)

  13. The influence of plasma density decreasement by pre-pulse on the laser wakefield acceleration

    Directory of Open Access Journals (Sweden)

    Ke-Gong Dong

    2011-12-01

    Full Text Available In the laser wakefield acceleration, the generation of electron beam is very sensitive to the plasma density. Not only the laser-wakefield interaction, but also the electron trapping and acceleration would be effected by the plasma density. However, the plasma density could be changed in the experiment by different reasons, which will result in the mismatch of parameters arranged initially. Forward Raman scattering spectrum demonstrated that the interaction density was decreased obviously in the experiment, which was verified by the pre-pulse conditions and two-dimensional particle-in-cell simulations. It was demonstrated that the plasma density was very important on the self-evolutions and energy coupling of laser pulse and wakefield, and eventually the energy spectrum of electron beam.

  14. An $ep$ collider based on proton-driven plasma wakefield acceleration

    CERN Document Server

    Wing, M.; Mete, O.; Aimidula, A.; Welsch, C.; Chattopadhyay, S.; Mandry, S.

    2014-01-01

    Recent simulations have shown that a high-energy proton bunch can excite strong plasma wakefields and accelerate a bunch of electrons to the energy frontier in a single stage of acceleration. This scheme could lead to a future $ep$ collider using the LHC for the proton beam and a compact electron accelerator of length 170 m, producing electrons of energy up to 100 GeV. The parameters of such a collider are discussed as well as conceptual layouts within the CERN accelerator complex. The physics of plasma wakefield acceleration will also be introduced, with the AWAKE experiment, a proof of principle demonstration of proton-driven plasma wakefield acceleration, briefly reviewed, as well as the physics possibilities of such an $ep$ collider.

  15. Self-injection threshold in self-guided laser wakefield accelerators

    Directory of Open Access Journals (Sweden)

    S. P. D. Mangles

    2012-01-01

    Full Text Available A laser pulse traveling through a plasma can excite large amplitude plasma waves that can be used to accelerate relativistic electron beams in a very short distance—a technique called laser wakefield acceleration. Many wakefield acceleration experiments rely on the process of wave breaking, or self-injection, to inject electrons into the wave, while other injection techniques rely on operation without self-injection. We present an experimental study into the parameters, including the pulse energy, focal spot quality, and pulse power, that determine whether or not a wakefield accelerator will self-inject. By taking into account the processes of self-focusing and pulse compression we are able to extend a previously described theoretical model, where the minimum bubble size k_{p}r_{b} required for trapping is not constant but varies slowly with density and find excellent agreement with this model.

  16. Analysis and control of wakefields in X-band crab cavities for Compact Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Ambattu, P.K., E-mail: praveen-kumar.ambattu@stfc.ac.uk [Cockcroft Institute, Warrington WA4 4AD (United Kingdom); Lancaster University, Lancaster LA1 4 YW (United Kingdom); Burt, G. [Cockcroft Institute, Warrington WA4 4AD (United Kingdom); Lancaster University, Lancaster LA1 4 YW (United Kingdom); Khan, V.F.; Jones, R.M. [Cockcroft Institute, Warrington WA4 4AD (United Kingdom); University of Manchester, Manchester M13 9PL (United Kingdom); Dexter, A. [Cockcroft Institute, Warrington WA4 4AD (United Kingdom); Lancaster University, Lancaster LA1 4 YW (United Kingdom); Dolgashev, V. [SLAC, Menlo Park, CA 94025 (United States)

    2011-11-21

    The Compact Linear Collider requires a crab cavity on each beamline prior to the interaction point to rotate the bunches before collision. The cavities are X-band travelling wave type and are located close to the final doublet of the beam delivery system. This makes the beam very sensitive to transverse momentum imparted by wakefields; hence the wakefields must be tightly controlled. Of special concerns are the orthogonal polarisation of the operating mode and the fundamental monopole mode of the crab cavity. The former mode is at the same frequency as the operating mode of a cylindrically symmetric cavity and the latter one is at a lower frequency and hence is difficult to damp using a single means. In this paper major problematic modes of the crab cavity are investigated and damping requirements for them are calculated. Possibility of meeting the required wakefield control using waveguide damping and choke damping is thoroughly investigated. As a comparison, damped-detuning is also investigated.

  17. Experimental results of laser wakefield acceleration using a femtosecond terawatt laser pulse

    International Nuclear Information System (INIS)

    Kando, Masaki; Ahn, Hyeyoung; Dewa, Hideki

    1999-01-01

    Laser wakefield acceleration (LWA) experiments have been carried out in an underdense plasma driven by a 2 TW, 90 fs laser pulse synchronized with a 17 MeV RF linac electron injector at 10 Hz. Around optimum plasma densities for LWA, we have observed electrons accelerated to 35 MeV. Wakefield excitation has been confirmed by measuring the electron density oscillation with a frequency domain interferometer. At plasma densities higher than the optimum density, we have also observed high energy electrons over 100 MeV up to 200 MeV. (author)

  18. Plasma Wakefield Accelerated Beams for Demonstration of FEL Gain at FLASHForward

    OpenAIRE

    Niknejadi, Pardis; Aschikhin, Alexander; Hu, Zhanghu; Karstensen, Sven; Knetsch, Alexander; Kononenko, Olena; Libov, Vladyslav; Ludwig, Kai; Martinez de la Ossa, Alberto; Marutzky, Frank; Mehrling, Timon; Osterhoff, Jens; Behrens, Christopher; Palmer, Charlotte; Poder, Kristjan

    2017-01-01

    FLASHForward is the Future-ORiented Wakefield Accelerator Research and Development project at the DESY free-electron laser (FEL) facility FLASH. It aims to produce high-quality, GeV-energy electron beams over a plasma cell of a few centimeters. The plasma is created by means of a 25 TW Ti:Sapphire laser system. The plasma wakefield will be driven by high-current-density electron beams extracted from the FLASH accelerator. The project focuses on the advancement of plasma-based particle acceler...

  19. Modeling laser wakefield accelerators in a Lorentz boosted frame

    Energy Technology Data Exchange (ETDEWEB)

    Vay, J.-L.; Geddes, C.G.R.; Cormier-Michel, E.; Grote, D.P.

    2010-09-15

    Modeling of laser-plasma wakefield accelerators in an optimal frame of reference [1] is shown to produce orders of magnitude speed-up of calculations from first principles. Obtaining these speedups requires mitigation of a high frequency instability that otherwise limits effectiveness in addition to solutions for handling data input and output in a relativistically boosted frame of reference. The observed high-frequency instability is mitigated using methods including an electromagnetic solver with tunable coefficients, its extension to accomodate Perfectly Matched Layers and Friedman's damping algorithms, as well as an efficient large bandwidth digital filter. It is shown that choosing theframe of the wake as the frame of reference allows for higher levels of filtering and damping than is possible in other frames for the same accuracy. Detailed testing also revealed serendipitously the existence of a singular time step at which the instability level is minimized, independently of numerical dispersion, thus indicating that the observed instability may not be due primarily to Numerical Cerenkov as has been conjectured. The techniques developed for Cerenkov mitigation prove nonetheless to be very efficient at controlling the instability. Using these techniques, agreement at the percentage level is demonstrated between simulations using different frames of reference, with speedups reaching two orders of magnitude for a 0.1 GeV class stages. The method then allows direct and efficient full-scale modeling of deeply depleted laser-plasma stages of 10 GeV-1 TeV for the first time, verifying the scaling of plasma accelerators to very high energies. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively.

  20. Modeling laser wakefield accelerators in a Lorentz boosted frame

    Energy Technology Data Exchange (ETDEWEB)

    Vay, J.-L.; Geddes, C.G.R.; Cormier-Michel, E.; Grotec, D. P.

    2010-06-15

    Modeling of laser-plasma wakefield accelerators in an optimal frame of reference is shown to produce orders of magnitude speed-up of calculations from first principles. Obtaining these speedups requires mitigation of a high-frequency instability that otherwise limits effectiveness in addition to solutions for handling data input and output in a relativistically boosted frame of reference. The observed high-frequency instability is mitigated using methods including an electromagnetic solver with tunable coefficients, its extension to accomodate Perfectly Matched Layers and Friedman's damping algorithms, as well as an efficient large bandwidth digital filter. It is shown that choosing the frame of the wake as the frame of reference allows for higher levels of filtering and damping than is possible in other frames for the same accuracy. Detailed testing also revealed serendipitously the existence of a singular time step at which the instability level is minimized, independently of numerical dispersion, thus indicating that the observed instability may not be due primarily to Numerical Cerenkov as has been conjectured. The techniques developed for Cerenkov mitigation prove nonetheless to be very efficient at controlling the instability. Using these techniques, agreement at the percentage level is demonstrated between simulations using different frames of reference, with speedups reaching two orders of magnitude for a 0.1 GeV class stages. The method then allows direct and efficient full-scale modeling of deeply depleted laser-plasma stages of 10 GeV-1 TeV for the first time, verifying the scaling of plasma accelerators to very high energies. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively.

  1. Modeling laser wakefield accelerators in a Lorentz boosted frame

    International Nuclear Information System (INIS)

    Vay, J.-L.; Geddes, C.G.R.; Cormier-Michel, E.; Grote, D.P.

    2010-01-01

    Modeling of laser-plasma wakefield accelerators in an optimal frame of reference (1) is shown to produce orders of magnitude speed-up of calculations from first principles. Obtaining these speedups requires mitigation of a high frequency instability that otherwise limits effectiveness in addition to solutions for handling data input and output in a relativistically boosted frame of reference. The observed high-frequency instability is mitigated using methods including an electromagnetic solver with tunable coefficients, its extension to accommodate Perfectly Matched Layers and Friedman's damping algorithms, as well as an efficient large bandwidth digital filter. It is shown that choosing the frame of the wake as the frame of reference allows for higher levels of filtering and damping than is possible in other frames for the same accuracy. Detailed testing also revealed serendipitously the existence of a singular time step at which the instability level is minimized, independently of numerical dispersion, thus indicating that the observed instability may not be due primarily to Numerical Cerenkov as has been conjectured. The techniques developed for Cerenkov mitigation prove nonetheless to be very efficient at controlling the instability. Using these techniques, agreement at the percentage level is demonstrated between simulations using different frames of reference, with speedups reaching two orders of magnitude for a 0.1 GeV class stages. The method then allows direct and efficient full-scale modeling of deeply depleted laser-plasma stages of 10 GeV-1 TeV for the first time, verifying the scaling of plasma accelerators to very high energies. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively.

  2. INTERSTOCK EFFECT ON THE GROWTH OF MANDARIN CV BATU 55, TANGERINE CV PONTIANAK AND LIME CV NIMAS PROPAGATED BY GRAFTING

    Directory of Open Access Journals (Sweden)

    Sugiyatno A.

    2017-10-01

    Full Text Available Japansche citroen (JC rootstock is still the main choice for producing citrus seeds for its high availability and compatibility. Other rootstocks have been used in the production, yet they produce unsatisfying results. Based on the theory, there is an alternative to use rootstock as interstock in order to stimulate the growth of scion. The objective of this reseach is to understand the effect of interstock on the growth of Mandarin cv. Batu 55, Tangerine cv. Pontianak and Lime cv. Nimas. This research was conducted in the screen house of Tlekung Experimental Field of Indonesian Citrus and Subtropical Fruits Research Institute (ICSFRI in Batu-East Java, located on 950 m asl, from January to April 2016. This research was arranged in a CRD design with 4 replications and 24 interstock-scion combination treatments. The interstocks used in this study were Carizzo citrange, Citrumello, Poncirus trifoliata, Volkameriana, Rough lemon, Troyer citrange, Kanci and control (JC combined with 3 scions namely Mandarin cv. Batu 55, Tangerine cv. Pontianak and Lime cv. Nimas propagated by grafting. The result showed the percentage of successful grafting ranged between 37.5% to 100%, while the percentage of the shoot formed on grafted plants was 75%-100%. The use of Poncirus trifoliata as interstock has stimulated fastest bud break on Tangerine cv. Pontianak in just 24.75 days while the Troyer citrange has stimulated better shoot growth in Lime cv. Nimas, resulted to the highest shoot around 52.20 cm which was significantly different from other treatments. Meanwhile, Carizzo citrange has been found to have some influences to the plant diameter and the number of leave of Lime cv. Nimas but showed insignificant effect on the growth of its own diameter. The use of interstock showed that it can be used to promote the growth of scion which usually has slow growth when it is directly grafted on the rootstock.

  3. Extremely short relativistic-electron-bunch generation in the laser wakefield via novel bunch injection scheme

    NARCIS (Netherlands)

    Khachatryan, A.G.; van Goor, F.A.; Boller, Klaus J.; Reitsma, A.J.W.; Jaroszynski, D.A.

    2004-01-01

    Recently a new electron-bunch injection scheme for the laser wakefield accelerator has been proposed [JETP Lett. 74, 371 (2001); Phys. Rev. E 65, 046504 (2002)]. In this scheme, a low energy electron bunch, sent in a plasma channel just before a high-intensity laser pulse, is trapped in the laser

  4. Generation of ultra-short relativistic-electron-bunch by a laser wakefield

    NARCIS (Netherlands)

    Khachatryan, A.G.; Boller, Klaus J.; van Goor, F.A.

    2003-01-01

    The possibility of the generation of an ultra-short (about one micron long) relativistic (up to a few GeVs) electron-bunch in a moderately nonlinear laser wakefield excited in an underdense plasma by an intense laser pulse is investigated. The ultra-short bunch is formed by trapping, effective

  5. Wakefield issue and its impact on X-ray photon pulse in the SXFEL test facility

    Energy Technology Data Exchange (ETDEWEB)

    Song, Minghao; Li, Kai [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Feng, Chao [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Deng, Haixiao, E-mail: denghaixiao@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Liu, Bo; Wang, Dong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2016-06-21

    Besides the designed beam acceleration, the energy of electrons is changed by the longitudinal wakefields in a real free-electron laser (FEL) facility, which may degrade FEL performances from the theoretical expectation. In this paper, with the help of simulation codes, the wakefields induced beam energy loss in the sophisticated undulator section is calculated for Shanghai soft X-ray FEL, which is a two-stage seeded FEL test facility. While the 1st stage 44 nm FEL output is almost not affected by the wakefields, it is found that a beam energy loss about 0.8 MeV degrades the peak brightness of the 2nd stage 8.8 nm FEL by a factor of 1.6, which however can be compensated by a magnetic field fine tuning of each undulator segment. And the longitudinal coherence of the 8.8 nm FEL output illustrates a slight degradation, because of the beam energy curvatures induced by the wakefields.

  6. Study of Laser Wakefield Accelerators as injectors for Synchrotron light sources

    CERN Document Server

    Hillenbrand, Steffen; Müller, Anke-Susanne; Jansen, Oliver; Judin, Vitali; Pukhov, Alexander

    2014-01-01

    Laser WakeField Accelerators (LWFA) feature short bunch lengths and high peak currents, combined with a small facility footprint. This makes them very interesting as injectors for Synchrotron light sources. Using the ANKA Synchrotron as an example, we investigate the possibility to inject a LWFA bunch into an electron storage ring. Particular emphasis is put on the longitudinal evolution of the bunch.

  7. The Experimental Stand for Research of Wakefield Method of Charged Particles Acceleration

    International Nuclear Information System (INIS)

    Kiselev, V.A.; Linnik, A.F.; Onishchenko, I.N.; Onishchenko, N.I.; Sotnikov, G.V.; Uskov, V.V.

    2006-01-01

    The experimental installation and diagnostic equipment with motivation to use for various researches of wakefield method of charged particles acceleration both in plasma and in dielectric structure has been described. The main parameters of a sequence of short relativistic electron bunch and values of physical characteristics of slow-down structures have been presented

  8. Experimental and Theoretical Researches of a Resonator Concept of a Dielectric Wakefield Accelerator

    International Nuclear Information System (INIS)

    Onishchenko, I.N.; Kiselev, V.A.; Linnik, A.F.; Onishchenko, N.I.; Sotnikov, G.V.; Uskov, V.V.

    2006-01-01

    Wakefield excitation in a cylindrical dielectric waveguide or resonator by a regular sequence of electron bunches foe application to high-gradient particle acceleration has been investigated theoretically and experimentally using an electron linac 'ALMAZ-2' (4.5 MeV, 6.10 3 bunches of duration 60 ps and charge 0.32 nC each)

  9. Analytical model for electromagnetic radiation from a wakefield excited by intense short laser pulses in an unmagnetized plasma

    Energy Technology Data Exchange (ETDEWEB)

    Chen Ziyu; Chen Shi; Dan Jiakun; Li Jianfeng; Peng Qixian, E-mail: ziyuch@gmail.com [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China)

    2011-10-15

    A simple one-dimensional analytical model for electromagnetic emission from an unmagnetized wakefield excited by an intense short-pulse laser in the nonlinear regime has been developed in this paper. The expressions for the spectral and angular distributions of the radiation have been derived. The model suggests that the origin of the radiation can be attributed to the violent sudden acceleration of plasma electrons experiencing the accelerating potential of the laser wakefield. The radiation process could help to provide a qualitative interpretation of existing experimental results, and offers useful information for future laser wakefield experiments.

  10. Analytical model for electromagnetic radiation from a wakefield excited by intense short laser pulses in an unmagnetized plasma

    International Nuclear Information System (INIS)

    Chen Ziyu; Chen Shi; Dan Jiakun; Li Jianfeng; Peng Qixian

    2011-01-01

    A simple one-dimensional analytical model for electromagnetic emission from an unmagnetized wakefield excited by an intense short-pulse laser in the nonlinear regime has been developed in this paper. The expressions for the spectral and angular distributions of the radiation have been derived. The model suggests that the origin of the radiation can be attributed to the violent sudden acceleration of plasma electrons experiencing the accelerating potential of the laser wakefield. The radiation process could help to provide a qualitative interpretation of existing experimental results, and offers useful information for future laser wakefield experiments.

  11. Study of ultra-high gradient wakefield excitation by intense ultrashort laser pulses in plasma

    International Nuclear Information System (INIS)

    Kotaki, Hideyuki

    2002-12-01

    We investigate a mechanism of nonlinear phenomena in laser-plasma interaction, a laser wakefield excited by intense laser pulses, and the possibility of generating an intense bright electron source by an intense laser pulse. We need to understand and further employ some of these phenomena for our purposes. We measure self-focusing, filamentation, and the anomalous blueshift of the laser pulse. The ionization of gas with the self-focusing causes a broad continuous spectrum with blueshift. The normal blueshift depends on the laser intensity and the plasma density. We, however, have found different phenomenon. The laser spectrum shifts to fixed wavelength independent of the laser power and gas pressure above some critical power. We call the phenomenon 'anomalous blueshift'. The results are explained by the formation of filaments. An intense laser pulse can excite a laser wakefield in plasma. The coherent wakefield excited by 2 TW, 50 fs laser pulses in a gas-jet plasma around 10 18 cm -3 is measured with a time-resolved frequency domain interferometer (FDI). The density distribution of the helium gas is measured with a time-resolved Mach-Zehnder interferometer to search for the optimum laser focus position and timing in the gas-jet. The results show an accelerating wakefield excitation of 20 GeV/m with good coherency, which is useful for ultrahigh gradient particle acceleration in a compact system. This is the first time-resolved measurement of laser wakefield excitation in a gas-jet plasma. The experimental results are compared with a Particle-in-Cell (PIC) simulation. The pump-probe interferometer system of FDI and the anomalous blueshift will be modified to the optical injection system as a relativistic electron beam injector. In 1D PIC simulation we obtain the results of high quality intense electron beam acceleration. These results illuminate the possibility of a high energy and a high quality electron beam acceleration. (author)

  12. Optimization of a train of bunches for plasma wakefield acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Martorelli, Roberto

    2016-05-10

    Particle accelerators are a fundamental instrument for the understanding of fundamental mechanism in nature. The need of always higher energies for the particle beams requires a huge increase of the sizes of the accelerators using the actual technology. Moreover the highest energies are achieved nowadays by circular colliders, not perfectly suitable for acceleration of electrons and positrons due to the radiation losses. In order to overcome this problem a new branch of physics studying alternative technique for particle acceleration has been developed. Among the various alternatives a promising one is the plasma wakefield acceleration (PWFA), in which a driver bunch interacts with a cold background plasma, exciting a plasma wave. The electric field of the plasma wave is then used for the acceleration of a second bunch. Such a mechanism allows to reach fields strength far beyond currently available, limited by the dielectric strength of the material. Among the different driver configurations, a promising one is the use of a modulated beam, namely a train of bunches, that provides a coherent interference among the electric fields generated by the single bunches. Such mechanism is subjected to a renewed interest in view of the forthcoming AWAKE experiment at CERN in which the long proton beam produced at the SPS facility is used as a driver. This possibility is achieved thanks to the onset of the self-modulation instability that modulates the long beam in a train of approximately 100 bunches. In order to accelerate the witness bunch to high energies is necessary on the other hand an efficient exchange of energy from the driver to the accelerated bunch, as well as a long duration of the driver so that can propagates for kilometers. This thesis deals with this two last aspects. The aim of this work is to provide an optimization for the modulated driver in order to improve specific features of the PWFA. This work shows the possibility to achieve an improved efficiency

  13. Properties of Trapped Electron Bunches in a Plasma Wakefield Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, Neil; /SLAC

    2009-10-30

    Plasma-based accelerators use the propagation of a drive bunch through plasma to create large electric fields. Recent plasma wakefield accelerator (PWFA) experiments, carried out at the Stanford Linear Accelerator Center (SLAC), successfully doubled the energy for some of the 42 GeV drive bunch electrons in less than a meter; this feat would have required 3 km in the SLAC linac. This dissertation covers one phenomenon associated with the PWFA, electron trapping. Recently it was shown that PWFAs, operated in the nonlinear bubble regime, can trap electrons that are released by ionization inside the plasma wake and accelerate them to high energies. These trapped electrons occupy and can degrade the accelerating portion of the plasma wake, so it is important to understand their origins and how to remove them. Here, the onset of electron trapping is connected to the drive bunch properties. Additionally, the trapped electron bunches are observed with normalized transverse emittance divided by peak current, {epsilon}{sub N,x}/I{sub t}, below the level of 0.2 {micro}m/kA. A theoretical model of the trapped electron emittance, developed here, indicates that the emittance scales inversely with the square root of the plasma density in the non-linear 'bubble' regime of the PWFA. This model and simulations indicate that the observed values of {epsilon}{sub N,x}/I{sub t} result from multi-GeV trapped electron bunches with emittances of a few {micro}m and multi-kA peak currents. These properties make the trapped electrons a possible particle source for next generation light sources. This dissertation is organized as follows. The first chapter is an overview of the PWFA, which includes a review of the accelerating and focusing fields and a survey of the remaining issues for a plasma-based particle collider. Then, the second chapter examines the physics of electron trapping in the PWFA. The third chapter uses theory and simulations to analyze the properties of the trapped

  14. Wyoming CV Pilot Traveler Information Message Sample

    Data.gov (United States)

    Department of Transportation — This dataset contains a sample of the sanitized Traveler Information Messages (TIM) being generated by the Wyoming Connected Vehicle (CV) Pilot. The full set of TIMs...

  15. cv. “Sukali Ndiizi”- AAB

    African Journals Online (AJOL)

    Clara

    2013-03-27

    Mar 27, 2013 ... improve transformation and regeneration efficiency of banana (cv. “Sukali .... Vuylsteke (1989) proliferation medium in the tissue culture .... DNA repair machinery is more active during cell division ... Biology-Plant 40:31-45.

  16. Laser Wakefield Acceleration Driven by a CO2 Laser (STELLA-LW) - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Wayne D

    2008-06-27

    The original goals of the Staged Electron Laser Acceleration – Laser Wakefield (STELLA-LW) program were to investigate two new methods for laser wakefield acceleration (LWFA). In pseudo-resonant LWFA (PR-LWFA), a laser pulse experiences nonlinear pulse steepening while traveling through the plasma. This steepening allows the laser pulse to generate wakefields even though the laser pulse length is too long for resonant LWFA to occur. For the conditions of this program, PR-LWFA requires a minimum laser peak power of 3 TW and a low plasma density (10^16 cm^-3). Seeded self-modulated LWFA (seeded SM-LWFA) combines LWFA with plasma wakefield acceleration (PWFA). An ultrashort (~100 fs) electron beam bunch acts as a seed in a plasma to form a wakefield via PWFA. This wakefield is subsequently amplified by the laser pulse through a self-modulated LWFA process. At least 1 TW laser power and, for a ~100-fs bunch, a plasma density ~10^17 cm^-3 are required. STELLA-LW was located on Beamline #1 at the Brookhaven National Laboratory (BNL) Accelerator Test Facility (ATF). The ATF TW CO2 laser served as the driving laser beam for both methods. For PR-LWFA, a single bunch was to probe the wakefield produced by the laser beam. For seeded SM-LWFA, the ATF linac would produce two bunches, where the first would be the seed and the second would be the witness. A chicane would compress the first bunch to enable it to generate wakefields via PWFA. The plasma source was a short-length, gas-filled capillary discharge with the laser beam tightly focused in the center of the capillary, i.e., no laser guiding was used, in order to obtain the needed laser intensity. During the course of the program, several major changes had to be made. First, the ATF could not complete the upgrade of the CO2 laser to the 3 TW peak power needed for the PR-LWFA experiment. Therefore, the PR-LWFA experiment had to be abandoned leaving only the seeded SM-LWFA experiment. Second, the ATF discovered that the

  17. Numerical simulations of intense charged particle beam propagation in a dielectric wakefield accelerator

    International Nuclear Information System (INIS)

    Gai, W.; Kanareykin, A.D.; Kustov, A.L.; Simpson, J.

    1995-01-01

    The propagation of an intense electron beam through a long dielectric tube is a critical issue for the success of the dielectric wakefield acceleration scheme. Due to the head-tail instability, a high current charged particle beam cannot propagate long distance without external focusing. In this paper we examine the beam handling and control problem in the dielectric wakefield accelerator. We show that for the designed 15.6 GHz and 20 GHz dielectric structures a 150 MeV, 40 endash 100 nC beam can be controlled and propagate up to 5 meters without significant particle losses by using external applied focusing and defocusing channel (FODO) around the dielectric tube. Particle dynamics of the accelerated beam is also studied. Our results show that for typical dielectric acceleration structures, the head-tail instabilities can be conveniently controlled in the same way as the driver beam. copyright 1995 American Institute of Physics

  18. Performance of the Argonne Wakefield Accelerator facility and initial experimental results

    International Nuclear Information System (INIS)

    Gai, W.; Conde, M.; Cox, G.; Konecny, R.; Power, J.; Schoessow, P.; Simpson, J.; Barov, N.

    1996-01-01

    The Argonne Wakefield Accelerator (AWA) facility has begun its experimental program. This unique facility is designed to address advanced acceleration research which requires very short, intense electron bunches. The facility incorporates two photo-cathode based electron sources. One produces up to 100 nC, multi-kiloamp 'drive' bunches which are used to excite wakefields in dielectric loaded structures and in plasma. The second source produces much lower intensity 'witness' pulses which are used to probe the fields produced by the drive. The drive and witness pulses can be precisely timed as well as laterally positioned with respect to each other. We discuss commissioning, initial experiments, and outline plans for a proposed 1 GeV demonstration accelerator. (author)

  19. Performance of the Argonne Wakefield Accelerator Facility and initial experimental results

    International Nuclear Information System (INIS)

    Gai, W.; Conde, M.; Cox, G.; Konecny, R.; Power, J.; Schoessow, P.; Simpson, J.; Barov, N.

    1996-01-01

    The Argonne Wakefield Accelerator facility has begun its experimental program. It is designed to address advanced acceleration research requiring very short, intense electron bunches. It incorporates two photocathode based electron sources. One produces up to 100 nC, multi-kiloamp 'drive' bunches which are used to excite wakefields in dielectric loaded structures and in plasma. The second source produces much lower intensity 'witness' pulses which are used to probe the fields produced by the drive. The drive and witness pulses can be precisely timed as well as laterally positioned with respect to each other. This paper discusses commissioning, initial experiments, and outline plans for a proposed 1 GeV demonstration accelerator

  20. Electron trapping and acceleration by the plasma wakefield of a self-modulating proton beam

    CERN Document Server

    Lotov, K.V.; Petrenko, A.V.; Amorim, L.D.; Vieira, J.; Fonseca, R.A.; Silva, L.O.; Gschwendtner, E.; Muggli, P.

    2014-01-01

    It is shown that co-linear injection of electrons or positrons into the wakefield of the self-modulating particle beam is possible and ensures high energy gain. The witness beam must co-propagate with the tail part of the driver, since the plasma wave phase velocity there can exceed the light velocity, which is necessary for efficient acceleration. If the witness beam is many wakefield periods long, then the trapped charge is limited by beam loading effects. The initial trapping is better for positrons, but at the acceleration stage a considerable fraction of positrons is lost from the wave. For efficient trapping of electrons, the plasma boundary must be sharp, with the density transition region shorter than several centimeters. Positrons are not susceptible to the initial plasma density gradient.

  1. Numerical Verification of the Power Transfer and Wakefield Coupling in the CLIC Two-Beam Accelerator

    CERN Document Server

    Candel, Arno; NG, C; Rawat, V; Schussman, G; Ko, K; Syratchev, I; Grudiev, A; Wuensch, W

    2011-01-01

    The Compact Linear Collider (CLIC) provides a path to a multi-TeV accelerator to explore the energy frontier of High Energy Physics. Its two-beam accelerator (TBA) concept envisions complex 3D structures, which must be modeled to high accuracy so that simulation results can be directly used to prepare CAD drawings for machining. The required simulations include not only the fundamental mode properties of the accelerating structures but also the Power Extraction and Transfer Structure (PETS), as well as the coupling between the two systems. Time-domain simulations will be performed to understand pulse formation, wakefield damping, fundamental power transfer and wakefield coupling in these structures. Applying SLAC’s parallel finite element code suite, these large-scale problems will be solved on some of the largest supercomputers available. The results will help to identify potential issues and provide new insights on the design, leading to further improvements on the novel two-beam accelerator scheme.

  2. Initial results of the new high intensity electron gun at the Argonne Wakefield Accelerator

    International Nuclear Information System (INIS)

    Conde, M. E.; Gai, W.; Konecny, R.; Power, J. G.; Schoessow, P.; Sun, X.

    2000-01-01

    The authors report on the status of the new short bunch, high intensity electron gun at the Argonne Wakefield Accelerator. The 1-1/2 cell L-band photocathode RF gun is expected to produce 10--100 nC bunches with 2--5 ps rms pulse length and normalized emittance less than 100 mm mrad. The beam energy at the exit of the gun cavity will be in the range 7.5--10 MeV. A standing-wave linac structure operating at the same frequency (1.3 GHz) will increase the beam energy to about 15 MeV. This beam will be used in wakefield acceleration experiments with dielectric loaded structures. These travelling-wave dielectric loaded structures, operating at 7.8 and 15.6 GHz, will be excited by the propagation of single bunches or by trains of up to 32 electron bunches

  3. Control, timing, and data acquisition for the Argonne Wakefield Accelerator (AWA)

    International Nuclear Information System (INIS)

    Schoessow, P.; Ho, C.; Power, J.; Chojnacki, E.

    1993-01-01

    The AWA is a new facility primarily designed for wakefield acceleration experiments at the 100 MV/m scale, which incorporates a high current linac and rf photocathode electron source, a low emittance rf electron gun for witness beam generation, and associated beamlines and diagnostics. The control system is based on VME and CA-MAC electronics interfaced to a high performance work-station and provides some distributed processing capability. In addition to the control of linac rf, laser optics, and beamlines, the system is also used for acquisition of video data both from luminescent beam position monitors and from streak camera pulse length diagnostics. Online image feature extraction will permit wakefields to be computed during the course of data taking. The linac timing electronics and its interface to the control system is described

  4. Melanie Ulz: Auf dem Schlachtfeld des Empire. Männlichkeitskonzepte in der Bildproduktion zu Napoleons Ägyptenfeldzug. Marburg: Jonas Verlag 2008.

    Directory of Open Access Journals (Sweden)

    Wolfgang Schmale

    2010-11-01

    Full Text Available Der Ägyptenfeldzug Napoleons am Ende des 18. Jahrhunderts wurde im Nachhinein bildpublizistisch extensiv aufgearbeitet. Diese Publizistik wird von Melanie Ulz unter dem Gesichtspunkt dargestellter und sich wandelnder Männlichkeitskonzepte untersucht. Zentral entfaltet sich in den Visualisierungen der später so genannte „Orientalismus“. Dem europäischen/französischen Mann und Krieger wird der orientalische Mann als multivalentes und kulturell unterlegenes Wesen gegenübergestellt. Bei aller Subtilität der Kunst handelt es sich im Kern um die Gegenüberstellung von Stereotypen. Ulz kann in ihrer Studie überzeugend den sexuierten Subtext des Orientalismus nachweisen.Napoleon’s Campaign of Egypt at the end of the 18th century had afterwards been worked with and addressed in graphical media extensively. Melanie Ulz analyzes these media in respect to expressed as well as changing concepts of masculinity. The visualizations essentially display what has later been called “Orientalism”. The European/ French man and warrior is opposed to the Oriental man, who is depicted as multivalent and culturally inferior. Despite the subtlety of the art, the works basically deal with the opposition of stereotypes. Ulz manages to convincingly prove the sexualized subtext of Orientalism.

  5. Accelerating field step-up transformer in wake-field accelerators

    International Nuclear Information System (INIS)

    Chojnacki, E.; Gai, W.; Schoessow, P.; Simpson, J.

    1991-01-01

    In the wake-field scheme of particle acceleration, a short, intense drive bunch of electrons passes through a slow-wave structure, leaving behind high rf power in its wake field. The axial accelerating electric field associated with the rf can be quite large, > 100 MeV/m, and is used to accelerate a much less intense ''witness'' beam to eventual energies > 1 TeV. The rf power is deposited predominantly in the fundamental mode of the structure, which, for dielectric-lined waveguide as used at Argonne, is the TM 01 mode. In all likelihood on the field amplitude will be limited only by rf breakdown of the dielectric material, the limit of which is currently unknown in the short time duration, high frequency regime of wake-field acceleration operation. To obtain such strong electric fields with given wake-field rf power, the dimensions of the dielectric-lined waveguide have to be fairly small, OD of the order of a cm and ID of a few mm, and this gives rise to the generation of strong deflection modes with beam misalignment. While a scheme exists to damp such deflection modes on a bunch-to-bunch time scale, head-tail beam deflection could still be a problem and BNS damping as well as FODO focusing are incomplete cures. Presented here are details of a scheme by which the rf power is generated by in a large-diameter wake-field tube, where deflection mode generation by the intense drive beam is tolerable, and then fed into a small-diameter acceleration tube where the less intense witness beam is accelerated by the greatly enhanced axial electric field. The witness beam generates little deflection-mode power itself, even in the small acceleration tube, thus a final high-quality, high-energy electron beam is produced

  6. Wake-Field Wave Resonant Excitation in Magnetized Plasmas by Electromagnetic Pulse

    International Nuclear Information System (INIS)

    Milant'ev, V.P.; Turikov, V.A.

    2006-01-01

    In this paper the space charge wave excitation process at electromagnetic pulse propagation along external magnetic field in vicinity of electron cyclotron resonance. In hydrodynamic approach it is obtained an equation for plasma density under ponderomotive force action. With help of this equation we investigated a wake-field wave amplitude dependence from resonance detuning. The numerical simulation using a PIC method electromagnetic pulse propagation process in the resonant conditions was done

  7. On the quasi-monoenergetic electron beam generation in the laser wakefield acceleration

    International Nuclear Information System (INIS)

    Bulanov, S.V.; Tajima, Toshiki

    2005-01-01

    A new phase of laser acceleration research has entered, as signified by the recent reports in Nature 9/30/05 of the generation of quasi-monoenergetic electron beam by laser wakefield acceleration in three experiments. We survey the current status of experiments and offer their theoretical interpretation. We understand why the choice of parameters is of such importance and why the earlier experiments showed energy spectra far from monoenergy. (author)

  8. Wakefield and the diffraction model due to a flat beam moving past a conducting wedge

    International Nuclear Information System (INIS)

    Chao, A.W.; Henke, H.

    1995-07-01

    A collimator is often used to clean a beam of its excessive tail particles. If the beam intensity is high enough or if the beam is brought too close to the collimator, however, the wakefields generated by the beam-collimator interaction can cause additional beam tails to grow, thus defeating, or even worsening, the beam-tail cleaning process. The wakefield generated by a sheet beam moving past a conducting wedge has been obtained in closed form by Henke using the method of conformal mapping. This result is applied in the present work to obtain the wake force and the transverse kick received by a test charge moving with the beam. For the beam to be approximated as sheet beams, it is assumed to be flat and the collimator is assumed to have an infinite extent in the flat dimention. We derive an exact expression for the transverse wake force delivered to particles in the beam bunch. Implication of emittance growth as a beam passes closely by a collimator is discussed. We consider two idealized wedge geometries: In Section 2, when the wedge has the geometry as a disrupted beam pipe, and in Section 3, when it is like a semi-infinite screen. Unfortunately, we do not have solutions for more realistic collimator geometries such as when it is tapered to minimize the wakefield effects. However, our results should still serve as pessimistic limiting cases. An interesting opportunity is offered by our exact calculation of the wakefields: it can be used to confront the diffraction model used to estimate the high-frequency impedance of a cavity structure. It is shown that the field pattern, as well as the impedance, agrees with those obtained by the diffraction model in appropriate limits

  9. Design of an electron injector for multi-stages laser wakefield acceleration

    International Nuclear Information System (INIS)

    Audet, T.

    2016-01-01

    Laser wakefield acceleration (LWFA) is a particle acceleration process relying on the interaction between high intensity laser pulses, of the order of 10 18 W/cm 2 and a plasma. The plasma wave generated in the laser wake sustain high amplitude electric fields (1- 100 GV/m). Those electric fields are 3 orders of magnitude higher than maximum electric fields in radio frequency cavities and represent the main benefit of LWFA, allowing more compact acceleration. However improvements of the LWFA-produced electron bunches properties, stability and repetition rate are mandatory for LWFA to be usable for applications. A scheme to improve electron bunches properties and to potentially increase the repetition rate is multi-stage LWFA. The laser plasma electron source, called the injector, has to produce relatively low energy (50 - 100 MeV), but high charge, small size and low divergence electron bunches. Produced electron bunches then have to be transported and injected into a second stage to increase electron kinetic energy. The subject of this thesis is to study and design a laser wakefield electron injector for multistage LWFA. In the frame of CILEX and the two-stages LWFA program, a prototype of the injector was built : ELISA consisting in a variable length gas cell. The plasma electronic density, which is a critical parameter for the control of the electron bunches properties, was characterized both experimentally and numerically. ELISA was used at 2 different laser facilities and physical mechanisms linked to electron bunches properties were studied in function of experimental parameters. A range of experimental parameters suitable for a laser wakefield injector was determined. A magnetic transport and diagnostic line was also built, implemented and tested at the UHI100 laser facility of the CEA Saclay. It allowed a more precise characterization of electron bunches generated with ELISA as well as an estimation of the quality of transported electron bunches for their

  10. OpenCV for secret agents

    CERN Document Server

    Howse, Joseph

    2015-01-01

    This book is for programmers who want to expand their skills by building fun, smart, and useful systems with OpenCV. The projects are ideal in helping you to think creatively about the uses of computer vision, natural user interfaces, and ubiquitous computers (in your home, car, and hand).

  11. AstroCV: Astronomy computer vision library

    Science.gov (United States)

    González, Roberto E.; Muñoz, Roberto P.; Hernández, Cristian A.

    2018-04-01

    AstroCV processes and analyzes big astronomical datasets, and is intended to provide a community repository of high performance Python and C++ algorithms used for image processing and computer vision. The library offers methods for object recognition, segmentation and classification, with emphasis in the automatic detection and classification of galaxies.

  12. Acceleration of on-axis and ring-shaped electron beams in wakefields driven by Laguerre-Gaussian pulses

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guo-Bo [College of Science, National University of Defense Technology, Changsha 410073 (China); Key Laboratory for Laser Plasmas (MOE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Chen, Min, E-mail: minchen@sjtu.edu.cn, E-mail: yanyunma@126.com; Luo, Ji; Zeng, Ming; Yuan, Tao; Yu, Ji-Ye; Yu, Lu-Le; Weng, Su-Ming [Key Laboratory for Laser Plasmas (MOE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240 (China); Ma, Yan-Yun, E-mail: minchen@sjtu.edu.cn, E-mail: yanyunma@126.com [College of Science, National University of Defense Technology, Changsha 410073 (China); Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240 (China); Yu, Tong-Pu [College of Science, National University of Defense Technology, Changsha 410073 (China); Sheng, Zheng-Ming [Key Laboratory for Laser Plasmas (MOE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240 (China); SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2016-03-14

    The acceleration of electron beams with multiple transverse structures in wakefields driven by Laguerre-Gaussian pulses has been studied through three-dimensional (3D) particle-in-cell simulations. Under different laser-plasma conditions, the wakefield shows different transverse structures. In general cases, the wakefield shows a donut-like structure and it accelerates the ring-shaped hollow electron beam. When a lower plasma density or a smaller laser spot size is used, besides the donut-like wakefield, a central bell-like wakefield can also be excited. The wake sets in the center of the donut-like wake. In this case, both a central on-axis electron beam and a ring-shaped electron beam are simultaneously accelerated. Further, reducing the plasma density or laser spot size leads to an on-axis electron beam acceleration only. The research is beneficial for some potential applications requiring special pulse beam structures, such as positron acceleration and collimation.

  13. The Limbic-Prefrontal Network Modulated by Electroacupuncture at CV4 and CV12

    Directory of Open Access Journals (Sweden)

    Jiliang Fang

    2012-01-01

    Full Text Available fMRI studies showed that acupuncture could induce hemodynamic changes in brain networks. Many of these studies focused on whether specific acupoints could activate specific brain regions and were often limited to manual acupuncture at acupoints on the limbs. In this fMRI study, we investigated acupuncture's modulation effects on brain functional networks by electroacupuncture (EA at acupoints on the midline of abdomen. Acupoints Guanyuan (CV4 and Zhongwan (CV12 were stimulated in 21 healthy volunteers. The needling sensations, brain activation, and functional connectivity were studied. We found that the limbic-prefrontal functional network was deactivated by EA at CV4 and CV12. More importantly, the local functional connectivity was significantly changed during EA stimulation, and the change persisted during the period after the stimulation. Although minor differences existed, both acupoints similarly modulated the limbic-prefrontal functional network, which is overlapped with the functional circuits associated with emotional and cognitive regulation.

  14. Effect of Sodium Cyanide on Wheat (Triticum durum cv. Altar and T. aestivum cv. Cumhuriyet)

    DEFF Research Database (Denmark)

    Gemici, Meliha; Karshenass, A.M.; Tan, Kit

    2008-01-01

    The effect of sodium cyanide on the morphology of stem, leaves and grain yields of Triticum durum cv. Altar and Triticum aestivum cv. Cumhuriyet grown under glass was studied. Seeds were planted in six different sets of pots containing ordinary garden soil. After formation of the first leaves......, the first set was used as the control and watered using ordinary bottled water sold commercially. The other five sets with T. durum cv. Altar and T. aestivum cv. Cumhuriyet seedlings were additionally watered with various concentrations of sodium cyanide, the test-quantity used being 10-50 mg/L. Growth...... of individual plants was monitored until grain production. It was found that the sodium cyanide concentrations in the feed solutions affected plant stature, with the plants becoming progressively dwarfed with increasing dosage. Anomalies in the morphological and anatomical structure of the plant were also noted...

  15. Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics

    CERN Document Server

    Assmann, R.; Bohl, T.; Bracco, C.; Buttenschon, B.; Butterworth, A.; Caldwell, A.; Chattopadhyay, S.; Cipiccia, S.; Feldbaumer, E.; Fonseca, R.A.; Goddard, B.; Gross, M.; Grulke, O.; Gschwendtner, E.; Holloway, J.; Huang, C.; Jaroszynski, D.; Jolly, S.; Kempkes, P.; Lopes, N.; Lotov, K.; Machacek, J.; Mandry, S.R.; McKenzie, J.W.; Meddahi, M.; Militsyn, B.L.; Moschuering, N.; Muggli, P.; Najmudin, Z.; Noakes, T.C.Q.; Norreys, P.A.; Oz, E.; Pardons, A.; Petrenko, A.; Pukhov, A.; Rieger, K.; Reimann, O.; Ruhl, H.; Shaposhnikova, E.; Silva, L.O.; Sosedkin, A.; Tarkeshian, R.; Trines, R.M.G.N.; Tuckmantel, T.; Vieira, J.; Vincke, H.; Wing, M.; Xia, G.

    2014-01-01

    New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN -- the AWAKE experiment -- has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator.

  16. Proton-driven plasma wakefield acceleration: a path to the future of high-energy particle physics

    International Nuclear Information System (INIS)

    Assmann, R; Gross, M; Bingham, R; Holloway, J; Bohl, T; Bracco, C; Butterworth, A; Feldbaumer, E; Goddard, B; Gschwendtner, E; Buttenschön, B; Caldwell, A; Chattopadhyay, S; Cipiccia, S; Jaroszynski, D; Fonseca, R A; Grulke, O; Kempkes, P; Huang, C; Jolly, S

    2014-01-01

    New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach is to exploit the properties of plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or an electron bunch into the plasma. However, the maximum energy gain of electrons accelerated in a single plasma stage is limited by the energy of the driver. Proton bunches are the most promising drivers of wakefields to accelerate electrons to the TeV energy scale in a single stage. An experimental program at CERN—the AWAKE experiment—has been launched to study in detail the important physical processes and to demonstrate the power of proton-driven plasma wakefield acceleration. Here we review the physical principles and some experimental considerations for a future proton-driven plasma wakefield accelerator. (paper)

  17. Advances in the SLAC RDDS: Modeling Manifold Damping and its Effect on the Wakefield for the Next Linear Collider

    International Nuclear Information System (INIS)

    Jones, Roger M

    2000-01-01

    The RDDS (Rounded Damped Detuned Structure) accelerator damps the transverse wakefield excited by bunches of electrons traversing thousands of linear accelerator structures. Errors in the fabrication of the cells which constitute each structure can result in a wakefield which is resonantly driven by the bunches, leading to BBU (Beam Break Up) and to a substantial growth in the beam emittance. One means to avoid these deleterious effects is to provide additional damping of the manifold, via plating the walls of the manifold with an electrically lossy material such as canthol or by fabricating the wall with stainless steel rather than copper. Results are presented on the wakefield and emittance growth in structures with a moderately lossy manifold

  18. THE STUDY AND TREATMENT OF MOTHERS AND INFANTS, THEN AND NOW: MELANIE KLEIN'S "NOTES ON BABY" IN A CONTEMPORARY PSYCHOANALYTIC CONTEXT.

    Science.gov (United States)

    Aguayo, Joseph; Salomonsson, Björn

    2017-04-01

    This paper draws on Melanie Klein's (unpublished) observational notes of her infant grandson, written primarily in 1938 and 1939. Apart from moving glimpses into a young family's life, the notes contain astute observations of an infant's behavior and emotions. Compared with Klein's published writings, the style is less theoretical and polemical. Later, in his latency years, Klein's grandson was in analysis with Marion Milner, who in 1952 published a paper drawing on the treatment. The present paper focuses on (1) how observations and treatment of the same child and his family by clinicians in close relationships with each other (Klein, Milner, and Winnicott) fertilized reciprocal influence but also brought into question the validity of Klein's observations, and (2) the relative merits and contributions of various modalities in understanding the infant's psyche, including experimental research, direct observation, parent-infant psychotherapy, and reconstructions from older patients-as occurs, for example, in psychoanalysis. © 2017 The Psychoanalytic Quarterly, Inc.

  19. CV controls from design to operation

    CERN Document Server

    Blanc, D

    2002-01-01

    The cooling and Ventilation (CV) group has emphasised the need to redefine its organisational structure at the end of 98. The main objective of this operation was to ensure the CV group to be more competitive and efficient through the growing tasks of the LHC projects. The main evolution given to this reorganisation is that the new structure is more project oriented and then operates on three distinct axes: Design, Work and Operation. Process control project management requires a complete and early interaction and participation of all the actors involved. This procedure to be efficient and constructive must be considered and performed not only during the design stage but along the project planning phases and must go beyond the completion work including the process control operation activity. The paper explains the present project management for process control. It describes the present constraints and gives suggestions to a different approach to these projects to improve performances and efficiency of a contr...

  20. Optically controlled seeding of Raman forward scattering and injection of electrons in a self-modulated laser-wakefield accelerator

    International Nuclear Information System (INIS)

    Chen, W.-T.; Chien, T.-Y.; Lee, C.-H.; Lin, J.-Y.; Wang, J.; Chen, S.-Y.

    2004-01-01

    Optical seeding of plasma waves and the injection of electrons are key issues in self-modulated laser-wakefield accelerators. By implementing a copropagating laser prepulse with proper timing, we are able to control the growth of Raman forward scattering and the production of accelerated electrons. The dependence of the Raman intensity on prepulse timing indicates that the seeding of Raman forward scattering is dominated by the ionization-induced wakefield, and the dependence of the divergence and number of accelerated electrons further reveals that the stimulated Raman backward scattering of the prepulse plays the essential role of injecting hot electrons into the fast plasma wave driven by the main pulse

  1. Self-resonant wakefield excitation by intense laser pulse in plasmas

    International Nuclear Information System (INIS)

    Andreev, N.E.; Pogosova, A.A.; Gorbunov, L.M.; Ramazashvili, R.R.; Kirsanov, V.I.

    1993-01-01

    It is demonstrated by theoretical analysis and numerical calculations that in an underdense plasma the process of three-dimensional evolution of the short and strong laser pulse (with duration equal to several plasma periods) leads to compression and self-modulation of the pulse, so that during a fairly long period of time beats of pulse amplitude generates resonantly a strong and stable plasma wakefield. The intensity of the wake-field is so high that it can provide a new promising outlook for the plasma based accelerator concept. Linear analysis of dispersion relation predicts that taking into account transverse component of wavenumber considerably increases the growth rate of resonance instability of the pulse. The numerical simulations demonstrate that considered self-focusing and resonant-modulation instability are essentially three dimensional processes. Laser field evolution in each transverse cross section of the pulse is synchronized by the regular structure of plasma wave that is excited by the pulse. The considered effect of resonant modulation has a threshold. For the pulses with the intensity below the threshold the refraction dominates and no modulation appears. The studied phenomenon can be referred to as the Self-Resonant Wakefield (SRWF) excitation that is driven by self-focusing and self-modulation of laser pulse with quite a moderate initial duration. In fact, this method of excitation differs from both suggested in Ref.1 (PBWA) and in Refs.2,3 (LWFA), being even more than the combination of these concepts. Unlike the first scheme it does not require initially the two-frequency laser pulse, since the modulation here appears in the most natural way due to evolution of the pulse. In contrast with the LWFA, the considered SRWF generation scheme gives the possibility to raise the intensity of wake-excitation due to pulse self-focusing ( initial stage) and self modulation (second stage)

  2. Obtaining the Wakefield Due to Cell-to-Cell Misalignments in a Linear Accelerator Structure

    OpenAIRE

    Bane, Karl L. F.; Li, Zenghai

    2001-01-01

    A linear accelerator structure, such as will be used in the linacs of the JLC/NLC collider, is composed of on the order of 100 cells. The cells are constructed as individual cups that are brazed together to form a structure. Fabrication error will result in slight cell-to-cell misalignments along the finished structure. In this report we derive an approximation to the transverse wakefield of a structure with cell-to-cell misalignments in terms of the eigenfunctions and eigenvalues of the erro...

  3. Generation of annular, high-charge electron beams at the Argonne wakefield accelerator

    Science.gov (United States)

    Wisniewski, E. E.; Li, C.; Gai, W.; Power, J.

    2013-01-01

    We present and discuss the results from the experimental generation of high-charge annular(ring-shaped)electron beams at the Argonne Wakefield Accelerator (AWA). These beams were produced by using laser masks to project annular laser profiles of various inner and outer diameters onto the photocathode of an RF gun. The ring beam is accelerated to 15 MeV, then it is imaged by means of solenoid lenses. Transverse profiles are compared for different solenoid settings. Discussion includes a comparison with Parmela simulations, some applications of high-charge ring beams,and an outline of a planned extension of this study.

  4. Beam-beam instability driven by wakefield effects in linear colliders

    CERN Document Server

    Brinkmann, R; Schulte, Daniel

    2002-01-01

    The vertical beam profile distortions induced by wakefield effects in linear colliders (the so-called ``banana effect'') generate a beam-beam instability at the collision point when the vertical disruption parameter is large. We illustrate this effect in the case of the TESLA linear collider project. We specify the tolerance on the associated emittance growth, which translates into tolerances on injection jitter and, for a given tuning procedure, on structure misalignments. We look for possible cures based on fast orbit correction at the interaction point and using a fast luminosity monitor.

  5. A possible experiment at LEUTL to characterize surface roughness Wakefield effects

    International Nuclear Information System (INIS)

    Biedron, S.G.; Dattoli, G.; Fawley, W.M.; Freund, H.P.; Huang, Zhirong; Lewellen, J.W.; Milton, S.V.; Nuhn, H.D.

    2001-01-01

    Wakefield effects due to internal vacuum chamber roughness may increase the electron beam energy spread and so have become an immediate concern for future x-ray free-electron laser (FEL) project developments such as the SLAC Linac Coherent Light Source (LCLS) and the DESY TESLA x-ray FEL. We describe a possible experiment to characterize the effects of surface roughness on an FEL driven by self-amplified spontaneous emission (SASE) operation. Although the specific system described is not completely identical to the above-proposed projects, much useful scaling information could be obtained and applied to shorter wavelength systems

  6. Generation of annular, high-charge electron beams at the Argonne wakefield accelerator

    Science.gov (United States)

    Wisniewski, E. E.; Li, C.; Gai, W.; Power, J.

    2012-12-01

    We present and discuss the results from the experimental generation of high-charge annular(ring-shaped)electron beams at the Argonne Wakefield Accelerator (AWA). These beams were produced by using laser masks to project annular laser profiles of various inner and outer diameters onto the photocathode of an RF gun. The ring beam is accelerated to 15 MeV, then it is imaged by means of solenoid lenses. Transverse profiles are compared for different solenoid settings. Discussion includes a comparison with Parmela simulations, some applications of high-charge ring beams,and an outline of a planned extension of this study.

  7. Wakefield accelerator with hybrid plasma-dielectric structure of rectangular cross-section

    International Nuclear Information System (INIS)

    Kiselev, V.A.; Linnik, A.F.; Mirnyj, V.I.; Onishchenko, I.N.; Uskov, V.V.

    2010-01-01

    Increase of wakefield intensity at its excitation by a long train of relativistic electron bunches in the rectangular dielectric structure when it is filled with plasma of resonant density was experimentally observed. The first portion of the bunches, produced by electron linac 'Almaz-2', ionizes gas at atmospheric pressure so that plasma frequency becomes equal to bunch repetition frequency and to the frequency of principal Eigen mode of the dielectric structure. Excitation enhancement at such resonant conditions is being studied taking into account the improvement of bunch train propagation in the transit channel caused by charge compensation with plasma and the electrodynamics change of the dielectric structure at filling with plasma.

  8. Laser wakefield acceleration with high-power, few-cycle mid-IR lasers

    OpenAIRE

    Papp, Daniel; Wood, Jonathan C.; Gruson, Vincent; Bionta, Mina; Gruse, Jan-Niclas; Cormier, Eric; Najmudin, Zulfikar; Légaré, François; Kamperidis, Christos

    2018-01-01

    The study of laser wakefield electron acceleration (LWFA) using mid-IR laser drivers is a promising path for future laser driven electronaccelerators, when compared to traditional near-IR laser drivers uperating at 0.8-1 {\\mu}m central wavelength ({\\lambda}laser), as the necessary vector potential a_0 for electron injection can be achieved with smaller laser powers due to the linear dependence on {\\lambda}laser. In this work, we perform 2D PIC simulations on LWFA using few-cycle high power (5...

  9. EARTH, MOON, SUN, AND CV ACCRETION DISKS

    International Nuclear Information System (INIS)

    Montgomery, M. M.

    2009-01-01

    Net tidal torque by the secondary on a misaligned accretion disk, like the net tidal torque by the Moon and the Sun on the equatorial bulge of the spinning and tilted Earth, is suggested by others to be a source to retrograde precession in non-magnetic, accreting cataclysmic variable (CV) dwarf novae (DN) systems that show negative superhumps in their light curves. We investigate this idea in this work. We generate a generic theoretical expression for retrograde precession in spinning disks that are misaligned with the orbital plane. Our generic theoretical expression matches that which describes the retrograde precession of Earths' equinoxes. By making appropriate assumptions, we reduce our generic theoretical expression to those generated by others, or to those used by others, to describe retrograde precession in protostellar, protoplanetary, X-ray binary, non-magnetic CV DN, quasar, and black hole systems. We find that spinning, tilted CV DN systems cannot be described by a precessing ring or by a precessing rigid disk. We find that differential rotation and effects on the disk by the accretion stream must be addressed. Our analysis indicates that the best description of a retrogradely precessing spinning, tilted, CV DN accretion disk is a differentially rotating, tilted disk with an attached rotating, tilted ring located near the innermost disk annuli. In agreement with the observations and numerical simulations by others, we find that our numerically simulated CV DN accretion disks retrogradely precess as a unit. Our final, reduced expression for retrograde precession agrees well with our numerical simulation results and with selective observational systems that seem to have main-sequence secondaries. Our results suggest that a major source to retrograde precession is tidal torques like that by the Moon and the Sun on the Earth. In addition, these tidal torques should be common to a variety of systems where one member is spinning and tilted, regardless if

  10. Extremely short relativistic-electron-bunch generation in the laser wakefield via novel bunch injection scheme

    Directory of Open Access Journals (Sweden)

    A. G. Khachatryan

    2004-12-01

    Full Text Available Recently a new electron-bunch injection scheme for the laser wakefield accelerator has been proposed [JETP Lett. 74, 371 (2001JTPLA20021-364010.1134/1.1427124; Phys. Rev. E 65, 046504 (2002PLEEE81063-651X10.1103/PhysRevE.65.046504]. In this scheme, a low energy electron bunch, sent in a plasma channel just before a high-intensity laser pulse, is trapped in the laser wakefield, considerably compressed and accelerated to an ultrarelativistic energy. In this paper we show the possibility of the generation of an extremely short (on the order of 1   μm long or a few femtoseconds in duration relativistic-electron-bunch by this mechanism. The initial electron bunch, which can be generated, for example, by a laser-driven photocathode rf gun, should have an energy of a few hundred keVs to a few MeVs, a duration in the picosecond range or less and a relatively low concentration. The trapping conditions and parameters of an accelerated bunch are investigated. The laser pulse dynamics as well as a possible experimental setup for the demonstration of the injection scheme are also considered.

  11. AWAKE Design Report: A Proton-Driven Plasma Wakefield Acceleration Experiment at CERN

    CERN Document Server

    Caldwell, A; Lotov, K; Muggli, P; Wing, M

    2013-01-01

    The AWAKE Collaboration has been formed in order to demonstrate proton driven plasma wakefield acceleration for the first time. This technology could lead to future colliders of high energy but of a much reduced length compared to proposed linear accelerators. The SPS proton beam in the CNGS facility will be injected into a 10m plasma cell where the long proton bunches will be modulated into significantly shorter micro-bunches. These micro-bunches will then initiate a strong wakefield in the plasma with peak fields above 1 GV/m that will be harnessed to accelerate a bunch of electrons from about 20MeV to the GeV scale within a few meters. The experimental program is based on detailed numerical simulations of beam and plasma interactions. The main accelerator components, the experimental area and infrastructure required as well as the plasma cell and the diagnostic equipment are discussed in detail. First protons to the experiment are expected at the end of 2015 and this will be followed by an initial 3–4 ye...

  12. Modeling two-stage bunch compression with wakefields: Macroscopic properties and microbunching instability

    Directory of Open Access Journals (Sweden)

    R. A. Bosch

    2008-09-01

    Full Text Available In a two-stage compression and acceleration system, where each stage compresses a chirped bunch in a magnetic chicane, wakefields affect high-current bunches. The longitudinal wakes affect the macroscopic energy and current profiles of the compressed bunch and cause microbunching at short wavelengths. For macroscopic wavelengths, impedance formulas and tracking simulations show that the wakefields can be dominated by the resistive impedance of coherent edge radiation. For this case, we calculate the minimum initial bunch length that can be compressed without producing an upright tail in phase space and associated current spike. Formulas are also obtained for the jitter in the bunch arrival time downstream of the compressors that results from the bunch-to-bunch variation of current, energy, and chirp. Microbunching may occur at short wavelengths where the longitudinal space-charge wakes dominate or at longer wavelengths dominated by edge radiation. We model this range of wavelengths with frequency-dependent impedance before and after each stage of compression. The growth of current and energy modulations is described by analytic gain formulas that agree with simulations.

  13. Wakefield and Beam Centering Measurements of a Damped and Detuned X-Band Accelerator Structure

    International Nuclear Information System (INIS)

    Adolphsen, Chris

    1999-01-01

    In the Next Linear Collider (NLC) design, X-Band (11.4 GHz) accelerator structures are used to accelerate multibunch beams to several hundred GeV. Although these structures allow for high gradient operation, their strong deflecting modes impose a number of operational constraints. In particular, the long-range transverse wakefields generated by the bunches need to be reduced by about two orders of magnitude to prevent significant beam breakup. During the past five years, a reduction scheme that employs both detuning and damping of the structure dipole modes has been developed to meet this requirement. Several prototype Damped and Detuned Structures (DDS) have been built to test and refine this scheme. The wakefield of the latest version, DDS3, has recently been measured in the Accelerator Structure Setup (ASSET) facility at SLAC. In this paper, we present these results together with predictions based on an equivalent circuit model of the structure. We also present ASSET studies in which the beam-induced dipole signals that are coupled out for damping purposes are used to center the beam in the structure

  14. High-quality electron beam generation in a proton-driven hollow plasma wakefield accelerator

    Science.gov (United States)

    Li, Y.; Xia, G.; Lotov, K. V.; Sosedkin, A. P.; Hanahoe, K.; Mete-Apsimon, O.

    2017-10-01

    Simulations of proton-driven plasma wakefield accelerators have demonstrated substantially higher accelerating gradients compared to conventional accelerators and the viability of accelerating electrons to the energy frontier in a single plasma stage. However, due to the strong intrinsic transverse fields varying both radially and in time, the witness beam quality is still far from suitable for practical application in future colliders. Here we demonstrate the efficient acceleration of electrons in proton-driven wakefields in a hollow plasma channel. In this regime, the witness bunch is positioned in the region with a strong accelerating field, free from plasma electrons and ions. We show that the electron beam carrying the charge of about 10% of 1 TeV proton driver charge can be accelerated to 0.6 TeV with a preserved normalized emittance in a single channel of 700 m. This high-quality and high-charge beam may pave the way for the development of future plasma-based energy frontier colliders.

  15. Longitudinal gas-density profilometry for plasma-wakefield acceleration targets

    Energy Technology Data Exchange (ETDEWEB)

    Schaper, Lucas, E-mail: lschaper01@qub.ac.uk [Universität Hamburg, FB Physik, Institut für Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg (Germany); Goldberg, Lars; Kleinwächter, Tobias; Schwinkendorf, Jan-Patrick; Osterhoff, Jens [Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg (Germany)

    2014-03-11

    Precise tailoring of plasma-density profiles has been identified as one of the critical points in achieving stable and reproducible conditions in plasma wakefield accelerators. Here, the strict requirements of next generation plasma-wakefield concepts, such as hybrid-accelerators, with densities around 10{sup 17} cm{sup −3} pose challenges to target fabrication as well as to their reliable diagnosis. To mitigate these issues we combine target simulation with fabrication and characterization. The resulting density profiles in capillaries with gas jet and multiple in- and outlets are simulated with the fluid code OpenFOAM. Satisfactory simulation results then are followed by fabrication of the desired target shapes with structures down to the 10 µm level. The detection of Raman scattered photons using lenses with large collection solid angle allows to measure the corresponding longitudinal density profiles at different number densities and allows a detection sensitivity down to the low 10{sup 17} cm{sup −3} density range at high spatial resolution. This offers the possibility to gain insight into steep density gradients as for example in gas jets and at the plasma-to-vacuum transition.

  16. Development and characterization of plasma targets for controlled injection of electrons into laser-driven wakefields

    Science.gov (United States)

    Kleinwaechter, Tobias; Goldberg, Lars; Palmer, Charlotte; Schaper, Lucas; Schwinkendorf, Jan-Patrick; Osterhoff, Jens

    2012-10-01

    Laser-driven wakefield acceleration within capillary discharge waveguides has been used to generate high-quality electron bunches with GeV-scale energies. However, owing to fluctuations in laser and plasma conditions in combination with a difficult to control self-injection mechanism in the non-linear wakefield regime these bunches are often not reproducible and can feature large energy spreads. Specialized plasma targets with tailored density profiles offer the possibility to overcome these issues by controlling the injection and acceleration processes. This requires precise manipulation of the longitudinal density profile. Therefore our target concept is based on a capillary structure with multiple gas in- and outlets. Potential target designs are simulated using the fluid code OpenFOAM and those meeting the specified criteria are fabricated using femtosecond-laser machining of structures into sapphire plates. Density profiles are measured over a range of inlet pressures utilizing gas-density profilometry via Raman scattering and pressure calibration with longitudinal interferometry. In combination these allow absolute density mapping. Here we report the preliminary results.

  17. Longitudinal gas-density profilometry for plasma-wakefield acceleration targets

    Science.gov (United States)

    Schaper, Lucas; Goldberg, Lars; Kleinwächter, Tobias; Schwinkendorf, Jan-Patrick; Osterhoff, Jens

    2014-03-01

    Precise tailoring of plasma-density profiles has been identified as one of the critical points in achieving stable and reproducible conditions in plasma wakefield accelerators. Here, the strict requirements of next generation plasma-wakefield concepts, such as hybrid-accelerators, with densities around 1017 cm-3 pose challenges to target fabrication as well as to their reliable diagnosis. To mitigate these issues we combine target simulation with fabrication and characterization. The resulting density profiles in capillaries with gas jet and multiple in- and outlets are simulated with the fluid code OpenFOAM. Satisfactory simulation results then are followed by fabrication of the desired target shapes with structures down to the 10 μm level. The detection of Raman scattered photons using lenses with large collection solid angle allows to measure the corresponding longitudinal density profiles at different number densities and allows a detection sensitivity down to the low 1017 cm-3 density range at high spatial resolution. This offers the possibility to gain insight into steep density gradients as for example in gas jets and at the plasma-to-vacuum transition.

  18. Acceleration of electrons at wakefield excitation by a sequence of relativistic electron bunches in dielectric resonator

    International Nuclear Information System (INIS)

    Kiselev, V.A.; Linnik, A.F.; Mirnyj, V.I.; Onishchenko, I.N.; Uskov, V.V.

    2009-01-01

    Method is proposed to divide a regular sequence of electron bunches into parts of bunches driving wakefield and witness bunches, which should be accelerated. It allows to avoid the necessity of additional electron accelerator for witness bunches producing and the necessity of precision short time techniques of injection phase adjusting. The idea concludes to the frequency detuning between bunches repetition frequency and the frequency of the fundamental mode of excited wakefield. Experiments were carried out on the linear resonant accelerator 'Almaz-2', which injected in the dielectric resonator a sequence of 6000 short bunches of relativistic electrons with energy 4.5 MeV, charge 0.16 nC and duration 60 psec each, the repetition interval 360 ps. Frequency detuning was entered by change of frequency of the master generator of the klystron within the limits of one percent so that the phase taper on the length of bunches sequence achieved 2π. Energy spectra of electrons of bunches sequence, which have been propagated through the dielectric resonator are measured and analyzed

  19. Acceleration of a trailing positron bunch in a plasma wakefield accelerator

    International Nuclear Information System (INIS)

    Doche, A.; Beekman, C.; Corde, S.

    2017-01-01

    High gradients of energy gain and high energy efficiency are necessary parameters for compact, cost-efficient and high-energy particle colliders. Plasma Wakefield Accelerators (PWFA) offer both, making them attractive candidates for next-generation colliders. Here in these devices, a charge-density plasma wave is excited by an ultra-relativistic bunch of charged particles (the drive bunch). The energy in the wave can be extracted by a second bunch (the trailing bunch), as this bunch propagates in the wake of the drive bunch. While a trailing electron bunch was accelerated in a plasma with more than a gigaelectronvolt of energy gain, accelerating a trailing positron bunch in a plasma is much more challenging as the plasma response can be asymmetric for positrons and electrons. We report the demonstration of the energy gain by a distinct trailing positron bunch in a plasma wakefield accelerator, spanning nonlinear to quasi-linear regimes, and unveil the beam loading process underlying the accelerator energy efficiency. A positron bunch is used to drive the plasma wake in the experiment, though the quasi-linear wake structure could as easily be formed by an electron bunch or a laser driver. Finally, the results thus mark the first acceleration of a distinct positron bunch in plasma-based particle accelerators.

  20. LCLS X-Ray FEL Output Performance in the Presence of Highly Time-Dependent Undulator Wakefields

    International Nuclear Information System (INIS)

    Bane, Karl L.F.; Emma, Paul; Huang, Heinz-Dieter Nuhn; Stupakov, Gennady; Fawley, William M.; Reiche, Sven

    2005-01-01

    Energy loss due to wakefields within a long undulator, if not compensated by an appropriate tapering of the magnetic field strength, can degrade the FEL process by detuning the resonant FEL frequency. The wakefields arise from the vacuum chamber wall resistivity, its surface roughness, and abrupt changes in its aperture. For LCLS parameters, the resistive-wall component is the most critical and depends upon the chamber material (e.g., Cu) and its radius. Of recent interest[1] is the so-called ''AC'' component of the resistive-wall wake which can lead to strong variations on very short timescales (e.g., ∼ 20 0fs). To study the expected performance of the LCLS in the presence of these wakefields, we have made an extensive series of start-to-end SASE simulations with tracking codes PARMELA and ELEGANT, and time-dependent FEL simulation codes GENESIS1.3 and GINGER. We discuss the impact of the wakefield losses upon output energy, spectral bandwidth, and temporal envelope of the output FEL pulse, as well as the benefits of a partial compensation of the time-dependent wake losses obtained with a slight z-dependent taper in the undulator field. We compare the taper results to those predicted analytically[2

  1. LCLS X-Ray FEL Output Performance in the Presence of Highly Time-Dependent Undulator Wakefields

    CERN Document Server

    Fawley, W M; Emma, P; Huang, Z; Nuhn, H D; Reiche, S; Stupakov, G

    2005-01-01

    Energy loss due to wakefields within a long undulator, if not compensated by an appropriate tapering of the magnetic field strength, can degrade the FEL process by detuning the resonant FEL frequency. The wakefields arise from the vacuum chamber wall resistivity, its surface roughness, and abrupt changes in its aperture. For LCLS parameters, the resistive component is the most critical and depends upon the chamber wall material (e.g. Cu) and its radius. Of recent interest [1] is the so-called "AC" component of the resistive wake which can lead to strong variations on very short timescales (e.g. ~20 fs). To study the expected performance of the LCLS in the presence of these wakefields, we have made an extensive series of start-to-end SASE simulations with tracking codes PARMELA and ELEGANT, and time-dependent FEL simulation codes GENESIS1.3 and GINGER. We discuss the impact of the wakefield losses upon output energy, spectral bandwidth, and temporal envelope of the output FEL pulse, as well a...

  2. Optimization of the LCLS X-Rray FEL Output Performance in the Presence of Strong Undulator Wakefields

    CERN Document Server

    Reiche, Sven; Emma, Paul; Fawley, William M; Huang, Zhirong; Nuhn, Heinz-Dieter; Stupakov, Gennady

    2005-01-01

    The Linac Coherent Light Source (LCLS) Free-Electron Laser will operate in the wavelength range of 1.5 to 15 Angstroms. Energy loss due to wakefields within the long undulator can degrade the FEL process by detuning the resonant FEL frequency. The wakefields arise from the vacuum chamber wall resistivity, its surface roughness, and abrupt changes in its aperture. For LCLS parameters, the resistive component is the most critical and depends upon the chamber material (e.g. Cu) and its radius. To study the expected performance in the presence of these wakefields, we make a series of "start-to-end" simulations with tracking codes PARMELA and ELEGANT and time-dependent FEL simulation codes Genesis 1.3 and Ginger. We discuss the impact of the wakefield on output energy, spectral bandwidth, and temporal envelope of the output FEL pulse, as well as the benefits of a partial compensation obtained with a slight z dependent taper in the undulator field. We compare these results to those obtained by decreasing the bunch ...

  3. Learning openCV computer vision with the openCV library

    CERN Document Server

    Bradski, Gary

    2008-01-01

    Learning OpenCV puts you right in the middle of the rapidly expanding field of computer vision. Written by the creators of OpenCV, the widely used free open-source library, this book introduces you to computer vision and demonstrates how you can quickly build applications that enable computers to see" and make decisions based on the data. With this book, any developer or hobbyist can get up and running with the framework quickly, whether it's to build simple or sophisticated vision applications

  4. Experimental observation of constructive superposition of wakefields generated by electron bunches in a dielectric-lined waveguide

    Directory of Open Access Journals (Sweden)

    S. V. Shchelkunov

    2006-01-01

    Full Text Available We report results from an experiment that demonstrates the successful superposition of wakefields excited by 50 MeV bunches which travel ∼50  cm along the axis of a cylindrical waveguide which is lined with alumina. The bunches are prepared by splitting a single laser pulse prior to focusing it onto the cathode of an rf gun into two pulses and inserting an optical delay in the path of one of them. Wakefields from two short (5–6 psec 0.15–0.35 nC bunches are superimposed and the energy loss of each bunch is measured as the separation between the bunches is varied so as to encompass approximately one wakefield period (∼21   cm. A spectrum of ∼40   TM_{0m} eigenmodes is excited by the bunch. A substantial retarding wakefield (2.65   MV/m·nC for just the first bunch is developed because of the short bunch length and the narrow vacuum channel diameter (3 mm through which they move. The energy loss of the second bunch exhibits a narrow peak when the bunch spacing is varied by only 4 mm (13.5 psec. This experiment is compared with a related experiment reported by a group at the Argonne National Laboratory where the bunch spacing was not varied and a much weaker retarding wakefield (∼0.1   MV/m·nC for the first bunch comprising only about 10 eigenmodes was excited by a train of long (∼9   mm bunches.

  5. Organisation des travaux ST-CV

    CERN Document Server

    Martel, C; CERN. Geneva. ST Division

    2003-01-01

    Débutée il y a deux ans, la phase de construction des installations de refroidissement du LHC a atteint en 2003 son apogée. De nombreux autres projets sont également gérés par le groupe dans divers secteurs du laboratoire. La spécificité du groupe est de réaliser des installations complexes impliquant des spécificités diverses telles qu’aéraulique, hydraulique, électrique, etc. Pour faire face à ces demandes la section travaux du groupe ST CV a adopté une structure capable de réaliser ces divers projets avec un minimum de personnel. La première partie de ce document décrit l’organisation de la section travaux ST CV. Dans une deuxième partie, les auteurs dressent un état des lieux des chantiers par projet en décrivant plus particulièrement les activités dans les domaines du traitement d’air et de refroidissement par eau.

  6. Retendering of ST-CV maintenance contract

    CERN Document Server

    Battistin, M

    2003-01-01

    During the next three years, the ST/CV group will be deeply involved in the installation works for the LHC project. During this period the need for maintenance activity will decrease. The minimum level will be reached during the “long shutdown” of the PS and SPS machines in 2005. The budget for the maintenance will decrease accordingly, thus the CV group had to review its maintenance strategy. The new contract, which started on January 1st 2003, has been defined to cope with these workload variations during the next years and to guarantee the minimum maintenance activity on the existing equipment. A lump-sum contract based on a win-win strategy has been discarded. The contractor no longer has to guarantee the performance of the CERN cooling and ventilation systems. A new price list strategy based on performance indicators and penalties has been chosen. The contractor now has to guarantee the performance of every maintenance operation demanded by CERN. This modification obliged the Operation section of the...

  7. Parallel editing, multi-positionality and maximalism – cosmopolitan effects as explored in some art works by Melanie Jackson and Vivienne Dick

    Directory of Open Access Journals (Sweden)

    Rachel Garfield

    2013-08-01

    Full Text Available Garfield produces a critique of minimalist art practice by demonstrating how the artist Melanie Jackson’s Some things you are not allowed to send around the world (2003 and 2006 and the experimental film-maker Vivienne Dick’s Liberty’s booty (1980 – neither of which can be said to be about feeling ‘at home’ in the world, be it as a resident or as a nomad – examine global humanity through multi-positionality, excess and contingency, and thereby begin to articulate a new cosmopolitan relationship with the local – or, rather, with many different localities – in one and the same maximalist sweep of the work. ‘Maximalism’ in Garfield’s coinage signifies an excessive overloading (through editing, collage, and the sheer density of the range of the material that enables the viewer to insert themselves into the narrative of the work. In the art of both Jackson and Dick Garfield detects a refusal to know or to judge the world; instead, there is an attempt to incorporate the complexities of its full range into the singular vision of the work, challenging the viewer to identify what is at stake.

  8. Optimization And Single-Shot Characterization Of Ultrashort Thz Pulses From A Laser Wakefield Accelerator

    International Nuclear Information System (INIS)

    Plateau, G.R.; Matlis, N.H.; van Tilborg, J.; Geddes, C.G.R.; Toth, Cs.; Schroeder, C.B.; Leemans, W.P.

    2009-01-01

    We present spatiotemporal characterization of μJ-class ultrashort THz pulses generated from a laser wakefield accelerator (LWFA). Accelerated electrons, resulting from the interaction of a high-intensity laser pulse with a plasma, emit high-intensity THz pulses as coherent transition radiation. Such high peak-power THz pulses, suitable for high-field (MV/cm) pump-probe experiments, also provide a non-invasive bunch-length diagnostic and thus feedback for the accelerator. The characterization of the THz pulses includes energy measurement using a Golay cell, 2D sign-resolved electro-optic measurement and single-shot spatiotemporal electric-field distribution retrieval using a new technique, coined temporal electric-field cross-Correlation (TEX). All three techniques corroborate THz pulses of ∼ 5 μJ, with peak fields of 100's of kV/cm and ∼ 0.4 ps rms duration.

  9. Application of High-performance Visual Analysis Methods to Laser Wakefield Particle Acceleration Data

    International Nuclear Information System (INIS)

    Rubel, Oliver; Prabhat, Mr.; Wu, Kesheng; Childs, Hank; Meredith, Jeremy; Geddes, Cameron G.R.; Cormier-Michel, Estelle; Ahern, Sean; Weber, Gunther H.; Messmer, Peter; Hagen, Hans; Hamann, Bernd; Bethel, E. Wes

    2008-01-01

    Our work combines and extends techniques from high-performance scientific data management and visualization to enable scientific researchers to gain insight from extremely large, complex, time-varying laser wakefield particle accelerator simulation data. We extend histogram-based parallel coordinates for use in visual information display as well as an interface for guiding and performing data mining operations, which are based upon multi-dimensional and temporal thresholding and data subsetting operations. To achieve very high performance on parallel computing platforms, we leverage FastBit, a state-of-the-art index/query technology, to accelerate data mining and multi-dimensional histogram computation. We show how these techniques are used in practice by scientific researchers to identify, visualize and analyze a particle beam in a large, time-varying dataset

  10. Laser dynamics in transversely inhomogeneous plasma and its relevance to wakefield acceleration

    Science.gov (United States)

    Pathak, V. B.; Vieira, J.; Silva, L. O.; Nam, Chang Hee

    2018-05-01

    We present full set of coupled equations describing the weakly relativistic dynamics of a laser in a plasma with transverse inhomogeneity. We apply variational principle approach to obtain these coupled equations governing laser spot-size, transverse wavenumber, curvature, transverse centroid, etc. We observe that such plasma inhomogeneity can lead to stronger self-focusing. We further discuss the guiding conditions of laser in parabolic plasma channels. With the help of multi-dimensional particle in cell simulations the study is extended to the blowout regime of laser wakefield acceleration to show laser as well as self-injected electron bunch steering in plasma to generate unconventional particle trajectories. Our simulation results demonstrate that such transverse inhomogeneities due to asymmetric self focusing lead to asymmetric bubble excitation, thus inducing off-axis self-injection.

  11. Bubble shape and electromagnetic field in the nonlinear regime for laser wakefield acceleration

    International Nuclear Information System (INIS)

    Li, X. F.; Yu, Q.; Huang, S.; Kong, Q.; Gu, Y. J.; Kawata, S.

    2015-01-01

    The electromagnetic field in the electron “bubble” regime for ultra-intense laser wakefield acceleration was solved using the d'Alembert equations. Ignoring the residual electrons, we assume an ellipsoidal bubble forms under ideal conditions, with bubble velocity equal to the speed of light in vacuum. The general solution for bubble shape and electromagnetic field were obtained. The results were confirmed in 2.5D PIC (particle-in-cell) simulations. Moreover, slopes for the longitudinal electric field of larger than 0.5 were found in these simulations. With spherical bubbles, this slope is always smaller than or equal to 0.5. This behavior validates the ellipsoid assumption

  12. Photon acceleration versus frequency-domain interferometry for laser wakefield diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Dias, J M; Oliveira e Silva, L; Mendonca, J T [GoLP/Centro de Fisica de Plasmas, Inst. Superior Tecnico, Lisbon (Portugal)

    1998-03-01

    A detailed comparison between the photon acceleration diagnostic technique and the frequency-domain interferometric technique for laser wakefield diagnostics, by using ray-tracing equations is presented here. The dispersion effects on the probe beam and the implications of an arbitrary phase velocity of the plasma wave are discussed for both diagnostic techniques. In the presence of large amplitude plasma wave and long interaction distances significant frequency shifts can be observed. The importance of this effect on the determination of the phase and frequency shifts measurements given by each of the two diagnostic techniques, is also analyzed. The accuracy of both diagnostic techniques is discussed and some of their technical problems are reviewed. (author)

  13. Reduced 3d modeling on injection schemes for laser wakefield acceleration at plasma scale lengths

    Science.gov (United States)

    Helm, Anton; Vieira, Jorge; Silva, Luis; Fonseca, Ricardo

    2017-10-01

    Current modelling techniques for laser wakefield acceleration (LWFA) are based on particle-in-cell (PIC) codes which are computationally demanding. In PIC simulations the laser wavelength λ0, in μm-range, has to be resolved over the acceleration lengths in meter-range. A promising approach is the ponderomotive guiding center solver (PGC) by only considering the laser envelope for laser pulse propagation. Therefore only the plasma skin depth λp has to be resolved, leading to speedups of (λp /λ0) 2. This allows to perform a wide-range of parameter studies and use it for λ0 Tecnologia (FCT), Portugal, through Grant No. PTDC/FIS-PLA/2940/2014 and PD/BD/105882/2014.

  14. Experimental signatures of direct-laser-acceleration-assisted laser wakefield acceleration

    Science.gov (United States)

    Shaw, J. L.; Lemos, N.; Marsh, K. A.; Froula, D. H.; Joshi, C.

    2018-04-01

    The direct laser acceleration (DLA) of electrons in a laser wakefield accelerator (LWFA) operating in the forced or quasi-blowout regimes has been investigated through experiment and simulation. When there is a significant overlap between the trapped electrons and the drive laser in a LWFA cavity, the resulting electrons can gain energy from both the LWFA and the DLA mechanisms. Experimental work investigates the properties of the electron beams produced in a LWFA with ionization injection by dispersing those beams in the direction perpendicular to the laser polarization. These electron beams show certain spectral features that are characteristic of DLA. These characteristic features are reproduced using particle-in-cell simulations, where particle tracking was used to elucidate the roles of LWFA and DLA to the energy gain of the electrons in this experimental regime and to demonstrate that such spectral features are definitive signatures of the presence of DLA in LWFA.

  15. Wakefields generated by electron beams passing through a waveguide loaded with a slightly dispersive active medium

    Directory of Open Access Journals (Sweden)

    Andrey V. Tyukhtin

    2007-05-01

    Full Text Available The wakefields of a relativistic electron beam passing through a waveguide loaded with an active medium with weak resonant dispersion are considered. For the calculations in this paper, the parameters of the medium are those of a solution of fullerene (C_{60} in a nematic liquid crystal that exhibits activity in the X-band. It is shown that several of the TM accelerating modes can be amplified for the geometries under consideration; structures in which higher order modes are amplified exhibit essential advantages as PASERs. In particular, the amplification of the highest mode occurs in a structure loaded with a rather thick active medium layer that maximizes the energy stored by the active medium.

  16. Beam manipulation for compact laser wakefield accelerator based free-electron lasers

    International Nuclear Information System (INIS)

    Loulergue, A; Labat, M; Benabderrahmane, C; Couprie, M E; Evain, C; Malka, V

    2015-01-01

    Free-electron lasers (FELs) are a unique source of light, particularly in the x-ray domain. After the success of FELs based on conventional acceleration using radio-frequency cavities, an important challenge is the development of FELs based on electron bunching accelerated by a laser wakefield accelerator (LWFA). However, the present LWFA electron bunch properties do not permit use directly for a significant FEL amplification. It is known that longitudinal decompression of electron beams delivered by state-of-the-art LWFA eases the FEL process. We propose here a second order transverse beam manipulation turning the large inherent transverse chromatic emittances of LWFA beams into direct FEL gain advantage. Numerical simulations are presented showing that this beam manipulation can further enhance by orders of magnitude the peak power of the radiation. (paper)

  17. Production of a monoenergetic electron bunch in a self-injected laser-wakefield accelerator

    International Nuclear Information System (INIS)

    Chang, C.-L.; Hsieh, C.-T.; Ho, Y.-C.; Chen, Y.-S.; Lin, J.-Y.; Wang, J.; Chen, S.-Y.

    2007-01-01

    Production of a monoenergetic electron bunch in a self-injected laser-wakefield accelerator is investigated with a tomographic method which resolves the electron injection and acceleration processes. It is found that all the electrons in the monoenergetic electron bunch are injected at the same location in the plasma column and then accelerated with an acceleration gradient exceeding 2 GeV/cm. The injection position shifts with the position of pump-pulse focus, and no significant deceleration is observed for the monoenergetic electron bunch after it reaches the maximum energy. The results are consistent with the model of transverse wave breaking and beam loading for the injection of monoenergetic electrons. The tomographic method adds a crucial dimension to the whole array of existing diagnostics for laser beams, plasma waves, and electron beams. With this method the details of the underlying physical processes in laser-plasma interactions can be resolved and compared directly to particle-in-cell simulations

  18. Multiple quasi-monoenergetic electron beams from laser-wakefield acceleration with spatially structured laser pulse

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Y.; Li, M. H.; Li, Y. F.; Wang, J. G.; Tao, M. Z.; Han, Y. J.; Zhao, J. R.; Huang, K.; Yan, W. C.; Ma, J. L.; Li, Y. T. [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Chen, L. M., E-mail: lmchen@iphy.ac.cn [Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080 (China); Department of Physics and Astronomy and IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Li, D. Z. [Institute of High Energy Physics, CAS, Beijing 100049 (China); Chen, Z. Y. [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, Sichuan 621999 (China); Sheng, Z. M. [Department of Physics and Astronomy and IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Department of Physics, Scottish Universities Physics Alliance, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Zhang, J. [Department of Physics and Astronomy and IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2015-08-15

    By adjusting the focus geometry of a spatially structured laser pulse, single, double, and treble quasi-monoenergetic electron beams were generated, respectively, in laser-wakefield acceleration. Single electron beam was produced as focusing the laser pulse to a single spot. While focusing the laser pulse to two spots that are approximately equal in energy and size and intense enough to form their own filaments, two electron beams were produced. Moreover, with a proper distance between those two focal spots, three electron beams emerged with a certain probability owing to the superposition of the diffractions of those two spots. The energy spectra of the multiple electron beams are quasi-monoenergetic, which are different from that of the large energy spread beams produced due to the longitudinal multiple-injection in the single bubble.

  19. Mutual compensation of wakefield and chromatic effects of intense linac bunches

    International Nuclear Information System (INIS)

    Seeman, J.T.; Merminga, N.

    1990-05-01

    Mutual compensation of transverse and chromatic effects for intense electron bunches in a high-energy linac is a recent Novosibirsk idea which provides a new control of emittance enlargement. In this paper we elaborate on the principles and constraints for this new technique which requires careful matching of internal bunch parameters with external forces. With species values of the bunch length, bunch intensity, and klystron phasing, the transverse-wakefield-induced forces within the bunch can be cancelled by energy-dependent forces from the quadrupole lattice at all positions along the linac. Under these conditions the tolerances for quadrupole alignment, dipole stability, and injection launch errors are significantly relaxed. 7 refs., 8 figs

  20. Beam Transfer Line Design for a Plasma Wakefield Acceleration Experiment (AWAKE) at the CERN SPS

    CERN Document Server

    Bracco, C; Brethoux, D; Clerc, V; Goddard, B; Gschwendtner, E; Jensen, L K; Kosmicki, A; Le Godec, G; Meddahi, M; Muggli, P; Mutin, C; Osborne, O; Papastergiou, K; Pardons, A; Velotti, F M; Vincke, H

    2013-01-01

    The world’s first proton driven plasma wakefield acceleration experiment (AWAKE) is presently being studied at CERN. The experimentwill use a high energy proton beam extracted from the SPS as driver. Two possible locations for installing the AWAKE facility were considered: the West Area and the CNGS beam line. The previous transfer line from the SPS to the West Area was completely dismantled in 2005 and would need to be fully re-designed and re-built. For this option, geometric constraints for radiation protection reasons would limit the maximum proton beam energy to 300 GeV. The existing CNGS line could be used by applying only minor changes to the lattice for the final focusing and the interface between the proton beam and the laser, required for plasma ionisation and bunch-modulation seeding. The beam line design studies performed for the two options are presented.

  1. Laser wakefield electron acceleration. A novel approach employing supersonic microjets and few-cycle laser pulses

    International Nuclear Information System (INIS)

    Schmid, Karl

    2011-01-01

    This thesis covers the few-cycle laser-driven acceleration of electrons in a laser-generated plasma. This process, known as laser wakefield acceleration (LWFA), relies on strongly driven plasma waves for the generation of accelerating gradients in the vicinity of several 100 GV/m, a value four orders of magnitude larger than that attainable by conventional accelerators. This thesis demonstrates that laser pulses with an ultrashort duration of 8 fs and a peak power of 6 TW allow the production of electron energies up to 50 MeV via LWFA. The special properties of laser accelerated electron pulses, namely the ultrashort pulse duration, the high brilliance, and the high charge density, open up new possibilities in many applications of these electron beams. (orig.)

  2. Characterization of the equilibrium configuration for modulated beams in a plasma wakefield accelerator

    CERN Document Server

    Martorelli, Roberto

    2016-01-01

    We analyze the equilibrium configuration for a modulated beam with sharp boundaries exposed to the fields self-generated by the interaction with a plasma. Through a semi-analytical approach we show the presence of multiple equilibrium configurations and we determine the one more suitable for wakefield excitation. Once pointed out the absence of confinement for the front of the beam and the consequently divergence driven by the emittance, we study the evolution of the equilibrium configuration while propagating in the plasma, discarding all the others time-dependencies. We show the onset of a rigid backward drift of the equilibrium configuration and we provide an explanation in the increasing length of the first bunch.

  3. Simulation of ionization effects for high-density positron drivers in future plasma wakefield experiments

    International Nuclear Information System (INIS)

    Bruhwiler, D.L.; Dimitrov, D.A.; Cary, J.R.; Esarey, E.; Leemans, W.P.

    2003-01-01

    The plasma wakefield accelerator (PWFA) concept has been proposed as a potential energy doubler for present or future electron-positron colliders. Recent particle-in-cell (PIC) simulations have shown that the self-fields of the required electron beam driver can tunnel ionize neutral Li, leading to plasma wake dynamics differing significantly from that of a preionized plasma. It has also been shown, for the case of a preionized plasma, that the plasma wake of a positron driver differs strongly from that of an electron driver. We will present new PIC simulations, using the OOPIC code, showing the effects of tunneling ionization on the plasma wake generated by high-density positron drivers. The results will be compared to previous work on electron drivers with tunneling ionization and positron drivers without ionization. Parameters relevant to the energy doubler and the upcoming E-164x experiment at the Stanford Linear Accelerator Center will be considered

  4. Study of the round edge disk hole's effects on the frequency and wakefield in disc structure

    International Nuclear Information System (INIS)

    Wang Lanfa; Hou Mi; Zhang Chuang

    2001-01-01

    The effects of the round edge beam hole on the frequency and wake field are studied using variational method, which allows for rounded iris disk hole without any approximation in shape treatment. The frequencies and wake fields of accelerating mode and dipole mode are studied for different edge radius cases, including the flat edge shape that is often used to approximately represent the actual structure geometry. The edge hole shape has weak effect on the frequency, but strong effect on the wakefield. The study shows that the amounts of wake fields are not precise enough with the assumption of the flat edge beam hole as of round edge. The shape assumption brings loss factor 15% err for the most dangerous EH 16 mode

  5. Observation of laser multiple filamentation process and multiple electron beams acceleration in a laser wakefield accelerator

    International Nuclear Information System (INIS)

    Li, Wentao; Liu, Jiansheng; Wang, Wentao; Chen, Qiang; Zhang, Hui; Tian, Ye; Zhang, Zhijun; Qi, Rong; Wang, Cheng; Leng, Yuxin; Li, Ruxin; Xu, Zhizhan

    2013-01-01

    The multiple filaments formation process in the laser wakefield accelerator (LWFA) was observed by imaging the transmitted laser beam after propagating in the plasma of different density. During propagation, the laser first self-focused into a single filament. After that, it began to defocus with energy spreading in the transverse direction. Two filaments then formed from it and began to propagate independently, moving away from each other. We have also demonstrated that the laser multiple filamentation would lead to the multiple electron beams acceleration in the LWFA via ionization-induced injection scheme. Besides, its influences on the accelerated electron beams were also analyzed both in the single-stage LWFA and cascaded LWFA

  6. Time-resolved measurements with streaked diffraction patterns from electrons generated in laser plasma wakefield

    Science.gov (United States)

    He, Zhaohan; Nees, John; Hou, Bixue; Krushelnick, Karl; Thomas, Alec; Beaurepaire, Benoît; Malka, Victor; Faure, Jérôme

    2013-10-01

    Femtosecond bunches of electrons with relativistic to ultra-relativistic energies can be robustly produced in laser plasma wakefield accelerators (LWFA). Scaling the electron energy down to sub-relativistic and MeV level using a millijoule laser system will make such electron source a promising candidate for ultrafast electron diffraction (UED) applications due to the intrinsic short bunch duration and perfect synchronization with the optical pump. Recent results of electron diffraction from a single crystal gold foil, using LWFA electrons driven by 8-mJ, 35-fs laser pulses at 500 Hz, will be presented. The accelerated electrons were collimated with a solenoid magnetic lens. By applying a small-angle tilt to the magnetic lens, the diffraction pattern can be streaked such that the temporal evolution is separated spatially on the detector screen after propagation. The observable time window and achievable temporal resolution are studied in pump-probe measurements of photo-induced heating on the gold foil.

  7. Multistage Coupling of Laser-Wakefield Accelerators with Curved Plasma Channels

    Science.gov (United States)

    Luo, J.; Chen, M.; Wu, W. Y.; Weng, S. M.; Sheng, Z. M.; Schroeder, C. B.; Jaroszynski, D. A.; Esarey, E.; Leemans, W. P.; Mori, W. B.; Zhang, J.

    2018-04-01

    Multistage coupling of laser-wakefield accelerators is essential to overcome laser energy depletion for high-energy applications such as TeV-level electron-positron colliders. Current staging schemes feed subsequent laser pulses into stages using plasma mirrors while controlling electron beam focusing with plasma lenses. Here a more compact and efficient scheme is proposed to realize the simultaneous coupling of the electron beam and the laser pulse into a second stage. A partly curved channel, integrating a straight acceleration stage with a curved transition segment, is used to guide a fresh laser pulse into a subsequent straight channel, while the electrons continue straight. This scheme benefits from a shorter coupling distance and continuous guiding of the electrons in plasma while suppressing transverse beam dispersion. Particle-in-cell simulations demonstrate that the electron beam from a previous stage can be efficiently injected into a subsequent stage for further acceleration while maintaining high capture efficiency, stability, and beam quality.

  8. Electron beam manipulation, injection and acceleration in plasma wakefield accelerators by optically generated plasma density spikes

    Energy Technology Data Exchange (ETDEWEB)

    Wittig, Georg; Karger, Oliver S.; Knetsch, Alexander [Institute of Experimental Physics, University of Hamburg, 22761 Hamburg (Germany); Xi, Yunfeng; Deng, Aihua; Rosenzweig, James B. [Particle Beam Physics Laboratory, UCLA, Los Angeles, CA 90095 (United States); Bruhwiler, David L. [RadiaSoft LLC, Boulder, CO 80304 (United States); RadiaBeam Technologies LLC (United States); Smith, Jonathan [Tech-X UK Ltd, Daresbury, Cheshire WA4 4FS (United Kingdom); Sheng, Zheng-Ming; Jaroszynski, Dino A.; Manahan, Grace G. [Physics Department, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Hidding, Bernhard [Institute of Experimental Physics, University of Hamburg, 22761 Hamburg (Germany); Physics Department, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2016-09-01

    We discuss considerations regarding a novel and robust scheme for optically triggered electron bunch generation in plasma wakefield accelerators [1]. In this technique, a transversely propagating focused laser pulse ignites a quasi-stationary plasma column before the arrival of the plasma wake. This localized plasma density enhancement or optical “plasma torch” distorts the blowout during the arrival of the electron drive bunch and modifies the electron trajectories, resulting in controlled injection. By changing the gas density, and the laser pulse parameters such as beam waist and intensity, and by moving the focal point of the laser pulse, the shape of the plasma torch, and therefore the generated trailing beam, can be tuned easily. The proposed method is much more flexible and faster in generating gas density transitions when compared to hydrodynamics-based methods, and it accommodates experimentalists needs as it is a purely optical process and straightforward to implement.

  9. An ultrashort pulse ultra-violet radiation undulator source driven by a laser plasma wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Anania, M. P. [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); INFN, Laboratori Nazionali di Frascati, I-00044 Frascati (Italy); Brunetti, E.; Wiggins, S. M.; Grant, D. W.; Welsh, G. H.; Issac, R. C.; Cipiccia, S.; Shanks, R. P.; Manahan, G. G.; Aniculaesei, C.; Jaroszynski, D. A., E-mail: d.a.jaroszynski@strath.ac.uk [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Geer, S. B. van der; Loos, M. J. de [Pulsar Physics, Burghstraat 47, 5614 BC Eindhoven (Netherlands); Poole, M. W.; Shepherd, B. J. A.; Clarke, J. A. [ASTeC, STFC, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Gillespie, W. A. [SUPA, School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom); MacLeod, A. M. [School of Computing and Creative Technologies, University of Abertay Dundee, Dundee DD1 1HG (United Kingdom)

    2014-06-30

    Narrow band undulator radiation tuneable over the wavelength range of 150–260 nm has been produced by short electron bunches from a 2 mm long laser plasma wakefield accelerator based on a 20 TW femtosecond laser system. The number of photons measured is up to 9 × 10{sup 6} per shot for a 100 period undulator, with a mean peak brilliance of 1 × 10{sup 18} photons/s/mrad{sup 2}/mm{sup 2}/0.1% bandwidth. Simulations estimate that the driving electron bunch r.m.s. duration is as short as 3 fs when the electron beam has energy of 120–130 MeV with the radiation pulse duration in the range of 50–100 fs.

  10. Multi-gigaelectronvolt acceleration of positrons in a self-loaded plasma wakefield

    Energy Technology Data Exchange (ETDEWEB)

    Corde, Sebastien [SLAC National Accelerator Lab., Menlo Park, CA (United States); Adli, E. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Univ. of Oslo, Oslo (Norway); Allen, J. M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); An, W. [Univ. of California, Los Angeles, CA (United States); Clarke, C. I. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Delahaye, J. P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Frederico, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Gessner, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Green, S. Z. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hogan, M. J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Joshi, C. [Univ. of California, Los Angeles, CA (United States); Lipkowitz, N. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Litos, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Lu, W. [Tsinghua Univ., Beijing (China); Marsh, K. A. [Univ. of California, Los Angeles, CA (United States); Mori, W. B. [Univ. of California, Los Angeles, CA (United States); Schmeltz, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Vafaei-Najafabadi, N. [Univ. of California, Los Angeles, CA (United States); Walz, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Yakimenko, V. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Yocky, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Clayton, C. E. [Univ. of California, Los Angeles, CA (United States)

    2015-08-26

    New accelerator concepts must be developed to make future particle colliders more compact and affordable. The Plasma Wakefield Accelerator (PWFA) is one such concept, where the electric field of a plasma wake excited by a charged-particle bunch is used to accelerate a trailing bunch of particles. To apply plasma acceleration to particle colliders, it is imperative that both the electrons and their antimatter counterpart, the positrons, are efficiently accelerated at high fields using plasmas1. While substantial progress has recently been reported on high-field, high-efficiency acceleration of electrons in a PWFA powered by an electron bunch 2, such an electron-driven wake is unsuitable for the acceleration and focusing of a positron bunch. Here we demonstrate a new regime of PWFA where particles in the front of a single positron bunch transfer their energy to a substantial number of those in the rear of the same bunch by exciting a wakefield in the plasma. In the process, the accelerating field is altered – self-loaded – so that about a billion positrons gain five gigaelectronvolts (GeV) of energy with a narrow energy spread in a distance of just 1.3 meters. They extract about 30% of the wake’s energy and form a spectrally distinct bunch with as low as a 1.8% r.m.s. energy spread. This demonstrated ability of positron-driven plasma wakes to efficiently accelerate a significant number of positrons with a small energy spread may overcome the long-standing challenge of positron acceleration in plasma-based accelerators.

  11. Control of electron injection and acceleration in laser-wakefield accelerators

    International Nuclear Information System (INIS)

    Guillaume, E.

    2015-01-01

    Laser-plasma accelerators provide a promising compact alternative to conventional accelerators. Plasma waves with extremely strong electric fields are generated when a high intensity laser is focused into an underdense gas target. Electrons that are trapped in these laser-driven plasma waves can be accelerated up to energies of a few GeVs. Despite their great potential, laser-wakefield accelerators face some issues, regarding notably the stability and reproducibility of the beam when electrons are injected in the accelerating structure. In this manuscript, different techniques of electron injection are presented and compared, notably injection in a sharp density gradient and ionization injection. It is shown that combining these two methods allows for the generation of stable and tunable electron beams. We have also studied a way to manipulate the electron bunch in the phase-space in order to accelerate the bunch beyond the dephasing limit. Such a technique was used with quasi-monoenergetic electron beams to enhance their energy. Moreover, the origin of the evolution of the angular momentum of electrons observed experimentally was investigated. Finally, we demonstrated experimentally a new method - the laser-plasma lens - to strongly reduce the divergence of the electron beam. This laser-plasma lens consists of a second gas jet placed at the exit of the accelerator. The laser pulse drives a wakefield in this second jet whose focusing forces take advantage to reduce the divergence of the trailing electron bunch. A simple analytical model describing the principle is presented, underlining the major importance of the second jet length, density and distance from the first jet. Experimental demonstration of the laser-plasma lens shows a divergence reduction by a factor of 2.6 for electrons up to 300 MeV, in accordance with the model predictions

  12. Improvement of the quality of laser-wakefield accelerators: towards a compact free-electron laser

    International Nuclear Information System (INIS)

    Lehe, R.

    2014-01-01

    When an intense and short laser pulse propagates through an underdense gas, it can accelerate a fraction of the electrons of the gas, and thereby generate an electron bunch with an energy of a few hundreds of MeV. This phenomenon, which is referred to as laser-wakefield acceleration, has many potential applications, including the design of ultra-bright X-ray sources known as free electron lasers (FEL). However, these applications require the electron bunch to have an excellent quality (low divergence, emittance and energy spread). In this thesis, different solutions to improve the quality of the electron bunch are developed, both analytically and through the use of Particle-In-Cell (PIC) simulations. It is first shown however that PIC simulations tend to erroneously overestimate the emittance of the bunch, due to the numerical Cherenkov effect. Thus, in order to correctly estimate the emittance, a modified PIC algorithm is proposed, which is not subject to this unphysical Cherenkov effect. Using this algorithm, we have observed and studied a new mechanism to generate the electron bunch: optical transverse injection. This mechanism can produce bunches with a high charge, a low emittance and a low energy spread. In addition, we also proposed an experimental setup - the laser-plasma lens - which can strongly reduce the final divergence of the bunch. Finally, these results are put into context by discussing the properties required for the design of a compact FEL. It is shown in particular that laser-wakefield accelerator could be advantageously combined with innovative laser-plasma undulators, in order to produce bright X-rays sources. (author)

  13. IJ-OpenCV: Combining ImageJ and OpenCV for processing images in biomedicine.

    Science.gov (United States)

    Domínguez, César; Heras, Jónathan; Pascual, Vico

    2017-05-01

    The effective processing of biomedical images usually requires the interoperability of diverse software tools that have different aims but are complementary. The goal of this work is to develop a bridge to connect two of those tools: ImageJ, a program for image analysis in life sciences, and OpenCV, a computer vision and machine learning library. Based on a thorough analysis of ImageJ and OpenCV, we detected the features of these systems that could be enhanced, and developed a library to combine both tools, taking advantage of the strengths of each system. The library was implemented on top of the SciJava converter framework. We also provide a methodology to use this library. We have developed the publicly available library IJ-OpenCV that can be employed to create applications combining features from both ImageJ and OpenCV. From the perspective of ImageJ developers, they can use IJ-OpenCV to easily create plugins that use any functionality provided by the OpenCV library and explore different alternatives. From the perspective of OpenCV developers, this library provides a link to the ImageJ graphical user interface and all its features to handle regions of interest. The IJ-OpenCV library bridges the gap between ImageJ and OpenCV, allowing the connection and the cooperation of these two systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Low energy spread 100 MeV-1 GeV electron bunches from laser wakefield acceleration at LOASIS

    International Nuclear Information System (INIS)

    Geddes, C.G.R.; Esarey, E.; Michel, P.; Nagler, B.; Nakamura, K.; Plateau, G.R.; Schroeder, C.B.; Shadwick, B.A.; Toth, Cs.; Van Tilborg, J.; Leemans, W.P.; Hooker, S.M.; Gonsalves, A.J.; Michel, E.; Cary, J.R.; Bruhwiler, D.

    2006-01-01

    Experiments at the LOASIS laboratory of LBNL recently demonstrated production of 100 MeV electron beams with low energy spread and low divergence from laser wakefield acceleration. The radiation pressure of a 10 TW laser pulse guided over 10 diffraction ranges by a plasma density channel was used to drive an intense plasma wave (wakefield), producing acceleration gradients on the order of 100 GV/m in a mm-scale channel. Beam energy has now been increased from 100 to 1000 MeV by using a cm-scale guiding channel at lower density, driven by a 40TW laser, demonstrating the anticipated scaling to higher beam energies. Particle simulations indicate that the low energy spread beams were produced from self trapped electrons through the interplay of trapping, loading, and dephasing. Other experiments and simulations are also underway to control injection of particles into the wake, and hence improve beam quality and stability further

  15. Hybrid TE-TM scheme for time domain numerical calculations of wakefields in structures with walls of finite conductivity

    Directory of Open Access Journals (Sweden)

    Andranik Tsakanian

    2012-05-01

    Full Text Available In particle accelerators a preferred direction, the direction of motion, is well defined. If in a numerical calculation the (numerical dispersion in this direction is suppressed, a quite coarse mesh and moderate computational resources can be used to reach accurate results even for extremely short electron bunches. Several approaches have been proposed in the past decades to reduce the accumulated dispersion error in wakefield calculations for perfectly conducting structures. In this paper we extend the TE/TM splitting algorithm to a new hybrid scheme that allows for wakefield calculations in structures with walls of finite conductivity. The conductive boundary is modeled by one-dimensional wires connected to each boundary cell. A good agreement of the numerical simulations with analytical results and other numerical approaches is obtained.

  16. Analysis of radial and longitudinal field of plasma wakefield generated by a Laguerre-Gauss laser pulse

    Energy Technology Data Exchange (ETDEWEB)

    Firouzjaei, Ali Shekari; Shokri, Babak [Department of Physics, Shahid Beheshti University, G.C., Evin, Tehran 19839-63113 (Iran, Islamic Republic of)

    2016-06-15

    In the present paper, we study the wakes known as the donut wake which is generated by Laguerre-Gauss (LG) laser pulses. Effects of the special spatial profile of a LG pulse on the radial and longitudinal wakefields are presented via an analytical model in a weakly non-linear regime in two dimensions. Different aspects of the donut-shaped wakefields have been analyzed and compared with Gaussian-driven wakes. There is also some discussion about the accelerating-focusing phase of the donut wake. Variations of longitudinal and radial wakes with laser amplitude, pulse length, and pulse spot size have been presented and discussed. Finally, we present the optimum pulse duration for such wakes.

  17. Betatron radiation based diagnostics for plasma wakefield accelerated electron beams at the SPARC-LAB test facility

    International Nuclear Information System (INIS)

    Shpakov, V.; Anania, M.P.; Biagioni, A.; Chiadroni, E.; Cianchi, A.; Curcio, A.; Dabagov, S.; Ferrario, M.; Filippi, F.; Marocchino, A.; Paroli, B.; Pompili, R.; Rossi, A.R.; Zigler, A.

    2016-01-01

    Recent progress with wake-field acceleration has shown a great potential in providing high gradient acceleration fields, while the quality of the beams remains relatively poor. Precise knowledge of the beam size at the exit from the plasma and matching conditions for the externally injected beams are the key for improvement of beam quality. Betatron radiation emitted by the beam during acceleration in the plasma is a powerful tool for the transverse beam size measurement, being also non-intercepting. In this work we report on the technical solutions chosen at SPARC-LAB for such diagnostics tool, along with expected parameters of betatron radiation. - Highlights: • The betatron radiation parameters in SPARC-LAB wakefiled experiments were studied. • The differences with betatron radiation in other wake-field experiments were highlighted. • The solution for betatron radiation detection was investigated.

  18. Betatron radiation based diagnostics for plasma wakefield accelerated electron beams at the SPARC-LAB test facility

    Energy Technology Data Exchange (ETDEWEB)

    Shpakov, V.; Anania, M.P.; Biagioni, A.; Chiadroni, E. [INFN - LNF, via Enrico Fermi 40, 00044 Frascati (Italy); Cianchi, A. [INFN - LNF, via Enrico Fermi 40, 00044 Frascati (Italy); “Tor Vergata” University, via della Ricerca Scientifica 1, 00133 Rome (Italy); Curcio, A. [INFN - LNF, via Enrico Fermi 40, 00044 Frascati (Italy); Dabagov, S. [INFN - LNF, via Enrico Fermi 40, 00044 Frascati (Italy); P.N. Lebedev Physical Institute RAS, Leninskiy Prospekt 53, 119991 Moscow (Russian Federation); NRNU “MEPhI”, Kashirskoe highway 31, 115409 Moscow (Russian Federation); Ferrario, M.; Filippi, F. [INFN - LNF, via Enrico Fermi 40, 00044 Frascati (Italy); Marocchino, A. [Dipartimento SBAI Universitá di Roma ‘La Sapienza’, via Antonio Scarpa 14/16, 00161 Rome (Italy); Paroli, B. [INFN - MI, via Celoria 16, 20133 Milan (Italy); Pompili, R. [INFN - LNF, via Enrico Fermi 40, 00044 Frascati (Italy); Rossi, A.R. [INFN - MI, via Celoria 16, 20133 Milan (Italy); Zigler, A. [Racah Institute of Physics Hebrew University of Jerusalem (Israel)

    2016-09-01

    Recent progress with wake-field acceleration has shown a great potential in providing high gradient acceleration fields, while the quality of the beams remains relatively poor. Precise knowledge of the beam size at the exit from the plasma and matching conditions for the externally injected beams are the key for improvement of beam quality. Betatron radiation emitted by the beam during acceleration in the plasma is a powerful tool for the transverse beam size measurement, being also non-intercepting. In this work we report on the technical solutions chosen at SPARC-LAB for such diagnostics tool, along with expected parameters of betatron radiation. - Highlights: • The betatron radiation parameters in SPARC-LAB wakefiled experiments were studied. • The differences with betatron radiation in other wake-field experiments were highlighted. • The solution for betatron radiation detection was investigated.

  19. Localization of ionization-induced trapping in a laser wakefield accelerator using a density down-ramp

    CERN Document Server

    Hansson, M.; Ekerfelt, H.; Aurand, B.; Gallardo Ganzalez, I.; Desforges, F. G.; Davoine, X.; Maitrallain, A.; Reymond, S.; Monot, P.; Persson, A.; Dobosz Dufrénoy S.; Wahlström C-G.; Cros, B.; Lundh, O.

    2016-01-01

    We report on a study on controlled trapping of electrons, by field ionization of nitrogen ions, in laser wakefield accelerators in variable length gas cells. In addition to ionization-induced trapping in the density plateau inside the cells, which results in wide, but stable, electron energy spectra, a regime of ionization-induced trapping localized in the density down-ramp at the exit of the gas cells, is found. The resulting electron energy spectra are peaked, with 10% shot-to-shot fluctuations in peak energy. Ionization-induced trapping of electrons in the density down-ramp is a way to trap and accelerate a large number of electrons, thus improving the efficiency of the laser-driven wakefield acceleration.

  20. Calculation of Wakefields and Higher Order Modes for the Vacuum Chamber of the ATLAS Experiment for the HL-LHC

    CERN Document Server

    Wanzenberg, R

    2013-01-01

    A design study for a High Luminosity Large Hadron Collider (HL-LHC) was started to extend the discovery potential of the Large Hadron Collider (LHC). The HL-LHC study implies also an upgraded configuration of the ATLAS detector with a new beam pipe. The trapped Higher Order Modes (HOMs) and the short range wakefields for the new design of the vacuum chamber are calculated using the computer codes MAFIA and ECHO2D. The short range wakefields are characterized in terms of kick and loss parameters. For the HOMs the frequency the R/Q and the Q-values are given which can directly converted into impedance data. The obtained data are intended to be included into the impedance database of the HL-LHC.

  1. SHORT-RANGE WAKEFIELD IN A FLAT PILLBOX CAVITY GENERATED BY A SUB-RELATIVISTIC BEAM BUNCH

    International Nuclear Information System (INIS)

    WANG, H.; PALMER, R.B.; GALLARDO, J.

    2001-01-01

    The short-range wakefield between two parallel conducting plates generated by a sub-relativistic beam bunch has been solved analytically by the image charge method in time domain. Comparing with the traditional modal analysis in frequency domain, this algorithm simplifies the mathematics and reveals in greater details the physics of electromagnetic field generation, propagation, reflection and causality. The calculated results have an excellent agreement with MAFIA and ABC1 simulations in all range of beam velocities

  2. An accurate Rb density measurement method for a plasma wakefield accelerator experiment using a novel Rb reservoir

    CERN Document Server

    Öz, E.; Muggli, P.

    2016-01-01

    A method to accurately measure the density of Rb vapor is described. We plan on using this method for the Advanced Wakefield (AWAKE)~\\cite{bib:awake} project at CERN , which will be the world's first proton driven plasma wakefield experiment. The method is similar to the hook~\\cite{bib:Hook} method and has been described in great detail in the work by W. Tendell Hill et. al.~\\cite{bib:densitymeter}. In this method a cosine fit is applied to the interferogram to obtain a relative accuracy on the order of $1\\%$ for the vapor density-length product. A single-mode, fiber-based, Mach-Zenhder interferometer will be built and used near the ends of the 10 meter-long AWAKE plasma source to be able to make accurate relative density measurement between these two locations. This can then be used to infer the vapor density gradient along the AWAKE plasma source and also change it to the value desired for the plasma wakefield experiment. Here we describe the plan in detail and show preliminary results obtained using a prot...

  3. MuSiC: a Multibunch and multiparticle Simulation Code with an alternative approach to wakefield effects

    CERN Document Server

    Migliorati, M

    2015-01-01

    The simulation of beam dynamics in presence of collective effects requires a strong computational effort to take into account, in a self consistent way, the wakefield acting on a given charge and produced by all the others. Generally this is done by means of a convolution integral or sum. Moreover, if the electromagnetic fields consist of resonant modes with high quality factors, responsible, for example, of coupled bunch instabilities, a charge is also affected by itself in previous turns, and a very long record of wakefield must be properly taken into account. In this paper we present a new simulation code for the longitudinal beam dynamics in a circular accelerator, which exploits an alternative approach to the currently used convolution sum, reducing the computing time and avoiding the issues related to the length of wakefield for coupled bunch instabilities. With this approach it is possible to simulate, without the need of a large computing power, simultaneously, the single and multi-bunch beam dynamics...

  4. Improving Postharvest Storage of Apple Cv.

    Directory of Open Access Journals (Sweden)

    H. Etemadi Nasab

    2013-06-01

    Full Text Available Apple is one of the important fruit in Iran. according to respiration and ethylene production behaviors, apple classified as a climacteric fruit. Therefore, any treatments, which can inhibit or prevent the action of ethylene, they can increase the postharvest life of horticultural production. 1-methylcyclopropane (1-MCP is one of the chemical which is environmental save and use as a very small concentrations. In this experiment, the effects of 1-MCP at concentrations of 0 (as a control, 0.25, 0.5, 0.75 and 1 µl.l-1 were used in apple cv. "Golab Kohanz", a land race fruits which is cultivated from long times ago in Iran. After the 1-MCP treatment, they were moved to cold room at 2 ºC and RH of ca 90% for 60 days. Samples were removed from the cold room and analysis for physicochemical characteristics. "Golab Kohanz" apples treated with 1-MCP showed improved fruit firmness, titratable acidity (TA, and total soluble solid after 147 days at 2ºC , compared to the control non-treated fruits. Also, treatment with 1-MCP significantly reduced the incidence of superficial scald in "Golab Kohanze". In general, 1-MCP-treated apples delay ripening during storing in cold room and increased shelf life. Overall, the results indicate that 1-MCP has tremendous potential for maintaining apple quality during storage and post storage.

  5. Melanie II--a third-generation software package for analysis of two-dimensional electrophoresis images: I. Features and user interface.

    Science.gov (United States)

    Appel, R D; Palagi, P M; Walther, D; Vargas, J R; Sanchez, J C; Ravier, F; Pasquali, C; Hochstrasser, D F

    1997-12-01

    Although two-dimensional electrophoresis (2-DE) computer analysis software packages have existed ever since 2-DE technology was developed, it is only now that the hardware and software technology allows large-scale studies to be performed on low-cost personal computers or workstations, and that setting up a 2-DE computer analysis system in a small laboratory is no longer considered a luxury. After a first attempt in the seventies and early eighties to develop 2-DE analysis software systems on hardware that had poor or even no graphical capabilities, followed in the late eighties by a wave of innovative software developments that were possible thanks to new graphical interface standards such as XWindows, a third generation of 2-DE analysis software packages has now come to maturity. It can be run on a variety of low-cost, general-purpose personal computers, thus making the purchase of a 2-DE analysis system easily attainable for even the smallest laboratory that is involved in proteome research. Melanie II 2-D PAGE, developed at the University Hospital of Geneva, is such a third-generation software system for 2-DE analysis. Based on unique image processing algorithms, this user-friendly object-oriented software package runs on multiple platforms, including Unix, MS-Windows 95 and NT, and Power Macintosh. It provides efficient spot detection and quantitation, state-of-the-art image comparison, statistical data analysis facilities, and is Internet-ready. Linked to proteome databases such as those available on the World Wide Web, it represents a valuable tool for the "Virtual Lab" of the post-genome area.

  6. Dynamics of electron acceleration in laser-driven wakefields. Acceleration limits and asymmetric plasma waves

    Energy Technology Data Exchange (ETDEWEB)

    Popp, Antonia

    2011-12-16

    The experiments presented in this thesis study several aspects of electron acceleration in a laser-driven plasma wave. High-intensity lasers can efficiently drive a plasma wave that sustains electric fields on the order of 100 GV/m. Electrons that are trapped in this plasma wave can be accelerated to GeV-scale energies. As the accelerating fields in this scheme are 3-4 orders of magnitude higher than in conventional radio-frequency accelerators, the necessary acceleration distance can be reduced by the same factor, turning laser-wakefield acceleration (LWFA) into a promising compact, and potentially cheaper, alternative. However, laser-accelerated electron bunches have not yet reached the parameter standards of conventional accelerators. This work will help to gain better insight into the acceleration process and to optimize the electron bunch properties. The 25 fs, 1.8 J-pulses of the ATLAS laser at the Max-Planck-Institute of Quantum Optics were focused into a steady-state flow gas cell. This very reproducible and turbulence-free gas target allows for stable acceleration of electron bunches. Thus the sensitivity of electron parameters to subtle changes of the experimental setup could be determined with meaningful statistics. At optimized experimental parameters, electron bunches of {approx}50 pC total charge were accelerated to energies up to 450 MeV with a divergence of {approx}2 mrad FWHM. As, in a new design of the gas cell, its length can be varied from 2 to 14 mm, the electron bunch energy could be evaluated after different acceleration distances, at two different electron densities. From this evolution important acceleration parameters could be extracted. At an electron density of 6.43. 10{sup 18} cm{sup -3} the maximum electric field strength in the plasma wave was determined to be {approx}160 GV/m. The length after which the relativistic electrons outrun the accelerating phase of the electric field and are decelerated again, the so-called dephasing length

  7. Dynamics of electron acceleration in laser-driven wakefields. Acceleration limits and asymmetric plasma waves

    International Nuclear Information System (INIS)

    Popp, Antonia

    2011-01-01

    The experiments presented in this thesis study several aspects of electron acceleration in a laser-driven plasma wave. High-intensity lasers can efficiently drive a plasma wave that sustains electric fields on the order of 100 GV/m. Electrons that are trapped in this plasma wave can be accelerated to GeV-scale energies. As the accelerating fields in this scheme are 3-4 orders of magnitude higher than in conventional radio-frequency accelerators, the necessary acceleration distance can be reduced by the same factor, turning laser-wakefield acceleration (LWFA) into a promising compact, and potentially cheaper, alternative. However, laser-accelerated electron bunches have not yet reached the parameter standards of conventional accelerators. This work will help to gain better insight into the acceleration process and to optimize the electron bunch properties. The 25 fs, 1.8 J-pulses of the ATLAS laser at the Max-Planck-Institute of Quantum Optics were focused into a steady-state flow gas cell. This very reproducible and turbulence-free gas target allows for stable acceleration of electron bunches. Thus the sensitivity of electron parameters to subtle changes of the experimental setup could be determined with meaningful statistics. At optimized experimental parameters, electron bunches of ∼50 pC total charge were accelerated to energies up to 450 MeV with a divergence of ∼2 mrad FWHM. As, in a new design of the gas cell, its length can be varied from 2 to 14 mm, the electron bunch energy could be evaluated after different acceleration distances, at two different electron densities. From this evolution important acceleration parameters could be extracted. At an electron density of 6.43. 10 18 cm -3 the maximum electric field strength in the plasma wave was determined to be ∼160 GV/m. The length after which the relativistic electrons outrun the accelerating phase of the electric field and are decelerated again, the so-called dephasing length, was found to be 4.9 mm

  8. Acceleration of laser-injected electron beams in an electron-beam driven plasma wakefield accelerator

    International Nuclear Information System (INIS)

    Knetsch, Alexander

    2018-03-01

    Plasma wakefields deliver accelerating fields that are approximately a 100 times higher than those in conventional radiofrequency or even superconducting radiofrequency cavities. This opens a transformative path towards novel, compact and potentially ubiquitous accelerators. These prospects, and the increasing demand for electron accelerator beamtime for various applications in natural, material and life sciences, motivate the research and development on novel plasma-based accelerator concepts. However, these electron beam sources need to be understood and controlled. The focus of this thesis is on electron beam-driven plasma wakefield acceleration (PWFA) and the controlled injection and acceleration of secondary electron bunches in the accelerating wake fields by means of a short-pulse near-infrared laser. Two laser-triggered injection methods are explored. The first one is the Trojan Horse Injection, which relies on very good alignment and timing control between electron beam and laser pulse and then promises electron bunches with hitherto unprecedented quality as regards emittance and brightness. The physics of electron injection in the Trojan Horse case is explored with a focus on the final longitudinal bunch length. Then a theoretical and numerical study is presented that examines the physics of Trojan Horse injection when performed in an expanding wake generated by a smooth density down-ramp. The benefits are radically decreased drive-electron bunch requirements and a unique bunch-length control that enables longitudinal electron-bunch shaping. The second laser-triggered injection method is the Plasma Torch Injection, which is a versatile, all-optical laser-plasma-based method capable to realize tunable density downramp injection. At the SLAC National Laboratory, the first proof-of-principle was achieved both for Trojan Horse and Plasma Torch injection. Setup details and results are reported in the experimental part of the thesis along with the commissioning

  9. Rezension von: Melanie Krause: Weibliche Nutzer von Computerspielen. Differenzierte Betrachtung und Erklärung der Motive und Verhaltensweisen weiblicher Nutzer von Computerspielen. Wiesbaden: VS Verlag für Sozialwissenschaften 2010.

    Directory of Open Access Journals (Sweden)

    Astrid Deuber-Mankowsky

    2011-11-01

    Full Text Available In der 2010 veröffentlichten kommunikationswissenschaftlich ausgerichteten Studie geht es um eine quantitative Beschreibung des Nutzungsverhaltens und der Nutzungsmotive computerspielender Frauen. Melanie Krause argumentiert konsequent innerhalb der fachlichen Grenzen der neueren Mediennutzungsforschung. Wirklich neu ist der von ihr unternommene Versuch einer Spielerinnentypologisierung, indem sie auf der Basis der erhobenen Daten zum Nutzungsverhalten und zu Nutzungsmotiven der Spielerinnen vier Cluster gebildet hat. Diese werden mit vier Spielerinnentypen identifiziert, die allerdings hochgradig normativ besetzt sind. Aus der Perspektive der kritischen Gender Studies wäre eine Reflexion und Diskussion der in die Spielerinnentypologie eingeflossenen normativen Voraussetzungen wünschenswert.

  10. A practical introduction to computer vision with OpenCV

    CERN Document Server

    Dawson-Howe, Kenneth

    2014-01-01

    Explains the theory behind basic computer vision and provides a bridge from the theory to practical implementation using the industry standard OpenCV libraries Computer Vision is a rapidly expanding area and it is becoming progressively easier for developers to make use of this field due to the ready availability of high quality libraries (such as OpenCV 2).  This text is intended to facilitate the practical use of computer vision with the goal being to bridge the gap between the theory and the practical implementation of computer vision. The book will explain how to use the relevant OpenCV

  11. Guidelines on CV networking information flow optimization for Texas.

    Science.gov (United States)

    2017-03-01

    Recognizing the fundamental role of information flow in future transportation applications, the research team investigated the quality and security of information flow in the connected vehicle (CV) environment. The research team identified key challe...

  12. Calibration of ADRET voltage generator type CV102. Program CODAV

    International Nuclear Information System (INIS)

    Lagarde, Gerard.

    1978-07-01

    The CODAV programm studied by the Metrology SES/SME laboratory is used for the calibration of ADRET voltage generator type CV.102. A JCAM.10 microcomputer run the measurement cycle and the printout of the results [fr

  13. Nutritive evaluation of Medicago truncutula (cv. jernalong) pasture ...

    African Journals Online (AJOL)

    Nutritive evaluation of Medicago truncutula (cv. jernalong) pasture for sheep. 1. Seasonal .... obtained by laboratory work, using in vitro techniques. (Engels et al. .... model that was used to explain 92,3% of the variance in. IVDOM content.

  14. ACE3P Computations of Wakefield Coupling in the CLIC Two-Beam Accelerator

    International Nuclear Information System (INIS)

    Candel, Arno

    2010-01-01

    The Compact Linear Collider (CLIC) provides a path to a multi-TeV accelerator to explore the energy frontier of High Energy Physics. Its novel two-beam accelerator concept envisions rf power transfer to the accelerating structures from a separate high-current decelerator beam line consisting of power extraction and transfer structures (PETS). It is critical to numerically verify the fundamental and higher-order mode properties in and between the two beam lines with high accuracy and confidence. To solve these large-scale problems, SLAC's parallel finite element electromagnetic code suite ACE3P is employed. Using curvilinear conformal meshes and higher-order finite element vector basis functions, unprecedented accuracy and computational efficiency are achieved, enabling high-fidelity modeling of complex detuned structures such as the CLIC TD24 accelerating structure. In this paper, time-domain simulations of wakefield coupling effects in the combined system of PETS and the TD24 structures are presented. The results will help to identify potential issues and provide new insights on the design, leading to further improvements on the novel CLIC two-beam accelerator scheme.

  15. Exploiting multi-scale parallelism for large scale numerical modelling of laser wakefield accelerators

    International Nuclear Information System (INIS)

    Fonseca, R A; Vieira, J; Silva, L O; Fiuza, F; Davidson, A; Tsung, F S; Mori, W B

    2013-01-01

    A new generation of laser wakefield accelerators (LWFA), supported by the extreme accelerating fields generated in the interaction of PW-Class lasers and underdense targets, promises the production of high quality electron beams in short distances for multiple applications. Achieving this goal will rely heavily on numerical modelling to further understand the underlying physics and identify optimal regimes, but large scale modelling of these scenarios is computationally heavy and requires the efficient use of state-of-the-art petascale supercomputing systems. We discuss the main difficulties involved in running these simulations and the new developments implemented in the OSIRIS framework to address these issues, ranging from multi-dimensional dynamic load balancing and hybrid distributed/shared memory parallelism to the vectorization of the PIC algorithm. We present the results of the OASCR Joule Metric program on the issue of large scale modelling of LWFA, demonstrating speedups of over 1 order of magnitude on the same hardware. Finally, scalability to over ∼10 6 cores and sustained performance over ∼2 P Flops is demonstrated, opening the way for large scale modelling of LWFA scenarios. (paper)

  16. Three electron beams from a laser-plasma wakefield accelerator and the energy apportioning question

    CERN Document Server

    Yang, X; Reboredo Gil, David; Welsh, Gregor H; Li, Y.F; Cipiccia, Silvia; Ersfeld, Bernhard; Grant, D. W; Grant, P. A; Islam, Muhammad; Tooley, M.B; Vieux, Gregory; Wiggins, Sally; Sheng, Zheng-Ming; Jaroszynski, Dino

    2017-01-01

    Laser-wakefield accelerators are compact devices capable of delivering ultra-short electron bunches with pC-level charge and MeV-GeV energy by exploiting the ultra-high electric fields arising from the interaction of intense laser pulses with plasma. We show experimentally and through numerical simulations that a high-energy electron beam is produced simultaneously with two stable lowerenergy beams that are ejected in oblique and counter-propagating directions, typically carrying off 5–10% of the initial laser energy. A MeV, 10s nC oblique beam is ejected in a 30°–60° hollow cone, which is filled with more energetic electrons determined by the injection dynamics. A nC-level, 100s keV backward-directed beam is mainly produced at the leading edge of the plasma column. We discuss the apportioning of absorbed laser energy amongst the three beams. Knowledge of the distribution of laser energy and electron beam charge, which determine the overall efficiency, is important for various applications of laser-wake...

  17. Laser-wakefield accelerators for medical phase contrast imaging: Monte Carlo simulations and experimental studies

    Science.gov (United States)

    Cipiccia, S.; Reboredo, D.; Vittoria, Fabio A.; Welsh, G. H.; Grant, P.; Grant, D. W.; Brunetti, E.; Wiggins, S. M.; Olivo, A.; Jaroszynski, D. A.

    2015-05-01

    X-ray phase contrast imaging (X-PCi) is a very promising method of dramatically enhancing the contrast of X-ray images of microscopic weakly absorbing objects and soft tissue, which may lead to significant advancement in medical imaging with high-resolution and low-dose. The interest in X-PCi is giving rise to a demand for effective simulation methods. Monte Carlo codes have been proved a valuable tool for studying X-PCi including coherent effects. The laser-plasma wakefield accelerators (LWFA) is a very compact particle accelerator that uses plasma as an accelerating medium. Accelerating gradient in excess of 1 GV/cm can be obtained, which makes them over a thousand times more compact than conventional accelerators. LWFA are also sources of brilliant betatron radiation, which are promising for applications including medical imaging. We present a study that explores the potential of LWFA-based betatron sources for medical X-PCi and investigate its resolution limit using numerical simulations based on the FLUKA Monte Carlo code, and present preliminary experimental results.

  18. Externally Controlled Injection of Electrons by a Laser Pulse in a Laser Wakefield Electron Accelerator

    CERN Document Server

    Chen Szu Yuan; Chen Wei Ting; Chien, Ting-Yei; Lee, Chau-Hwang; Lin, Jiunn-Yuan; Wang, Jyhpyng

    2005-01-01

    Spatially and temporally localized injection of electrons is a key element for development of plasma-wave electron accelerator. Here we report the demonstration of two different schemes for electron injection in a self-modulated laser wakefield accelerator (SM-LWFA) by using a laser pulse. In the first scheme, by implementing a copropagating laser prepulse with proper timing, we are able to control the growth of Raman forward scattering and the production of accelerated electrons. We found that the stimulated Raman backward scattering of the prepulse plays the essential role of injecting hot electrons into the fast plasma wave driven by the pump pulse. In the second scheme, by using a transient density ramp we achieve self-injection of electrons in a SM-LWFA with spatial localization. The transient density ramp is produced by a prepulse propagating transversely to drill a density depression channel via ionization and expansion. The same mechanism of injection with comparable efficiency is also demonstrated wi...

  19. Sapphire capillaries for laser-driven wakefield acceleration in plasma. Fs-laser micromachining and characterization

    International Nuclear Information System (INIS)

    Schwinkendorf, Jan-Patrick

    2012-05-01

    Plasma wakefields are a promising approach for the acceleration of electrons with ultrahigh (10 to 100 GV/m) electric fields. Nowadays, high-intensity laser pulses are routinely utilized to excite these large-amplitude plasma waves. However, several detrimental effects such as laser diffraction, electron-wake dephasing and laser depletion may terminate the acceleration process. Two of these phenomena can be mitigated or avoided by the application of capillary waveguides, e.g. fabricated out of sapphire for longevity. Capillaries may compensate for laser diffraction like a fiber and allow for the creation of tapered gas-density profiles working against the dephasing between the accelerating wave and the particles. Additionally, they offer the possibility of controlled particle injection. This thesis is reporting on the set up of a laser for fs-micromachining of capillaries of almost arbitrary shapes and a test stand for density-profile characterization. These devices will permit the creation of tailored gas-density profiles for controlled electron injection and acceleration inside plasma.

  20. The UCLA/SLAC Ultra-High Gradient Cerenkov Wakefield Accelerator Experiment

    CERN Document Server

    Thompson, Matthew C; Hogan, Mark; Ischebeck, Rasmus; Muggli, Patric; Rosenzweig, James E; Scott, A; Siemann, Robert; Travish, Gil; Walz, Dieter; Yoder, Rodney

    2005-01-01

    An experiment is planned to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range. This new UCLA/SLAC collaboration will take advantage of the unique SLAC FFTB electron beam and its demonstrated ultra-short pulse lengths and high currents (e.g., sz = 20 μm at Q = 3 nC). The electron beam will be focused down and sent through varying lengths of fused silica capillary tubing with two different sizes: ID = 200 μm / OD = 325 μm and ID = 100 μm / OD = 325 μm. The pulse length of the electron beam will be varied in order to alter the accelerating gradient and probe the breakdown threshold of the dielectric structures. In addition to breakdown studies, we plan to collect and measure coherent Cerenkov radiation emitted from the capillary tube to gain information about the strength of the accelerating fields. Status and progress on the experiment are reported.

  1. Energy loss of a high charge bunched electron beam in plasma: Simulations, scaling, and accelerating wakefields

    Directory of Open Access Journals (Sweden)

    J. B. Rosenzweig

    2004-06-01

    Full Text Available The energy loss and gain of a beam in the nonlinear, “blowout” regime of the plasma wakefield accelerator, which features ultrahigh accelerating fields, linear transverse focusing forces, and nonlinear plasma motion, has been asserted, through previous observations in simulations, to scale linearly with beam charge. Additionally, from a recent analysis by Barov et al., it has been concluded that for an infinitesimally short beam, the energy loss is indeed predicted to scale linearly with beam charge for arbitrarily large beam charge. This scaling is predicted to hold despite the onset of a relativistic, nonlinear response by the plasma, when the number of beam particles occupying a cubic plasma skin depth exceeds that of plasma electrons within the same volume. This paper is intended to explore the deviations from linear energy loss using 2D particle-in-cell simulations that arise in the case of experimentally relevant finite length beams. The peak accelerating field in the plasma wave excited behind the finite-length beam is also examined, with the artifact of wave spiking adding to the apparent persistence of linear scaling of the peak field amplitude into the nonlinear regime. At large enough normalized charge, the linear scaling of both decelerating and accelerating fields collapses, with serious consequences for plasma wave excitation efficiency. Using the results of parametric particle-in-cell studies, the implications of these results for observing severe deviations from linear scaling in present and planned experiments are discussed.

  2. Computer simulations of a single-laser double-gas-jet wakefield accelerator concept

    Directory of Open Access Journals (Sweden)

    R. G. Hemker

    2002-04-01

    Full Text Available We report in this paper on full scale 2D particle-in-cell simulations investigating laser wakefield acceleration. First we describe our findings of electron beam generation by a laser propagating through a single gas jet. Using realistic parameters which are relevant for the experimental setup in our laboratory we find that the electron beam resulting after the propagation of a 0.8 μm, 50 fs laser through a 1.5 mm gas jet has properties that would make it useful for further acceleration. Our simulations show that the electron beam is generated when the laser exits the gas jet, and the properties of the generated beam, especially its energy, depend only weakly on most properties of the gas jet. We therefore propose to use the first gas jet as a plasma cathode and then use a second gas jet placed immediately behind the first to provide additional acceleration. Our simulations of this proposed setup indicate the feasibility of this idea and also suggest ways to optimize the quality of the resulting beam.

  3. Temporal characterization of ultrashort linearly chirped electron bunches generated from a laser wakefield accelerator

    Directory of Open Access Journals (Sweden)

    C. J. Zhang

    2016-06-01

    Full Text Available A new method for diagnosing the temporal characteristics of ultrashort electron bunches with linear energy chirp generated from a laser wakefield accelerator is described. When the ionization-injected bunch interacts with the back of the drive laser, it is deflected and stretched along the direction of the electric field of the laser. Upon exiting the plasma, if the bunch goes through a narrow slit in front of the dipole magnet that disperses the electrons in the plane of the laser polarization, it can form a series of bunchlets that have different energies but are separated by half a laser wavelength. Since only the electrons that are undeflected by the laser go through the slit, the energy spectrum of the bunch is modulated. By analyzing the modulated energy spectrum, the shots where the bunch has a linear energy chirp can be recognized. Consequently, the energy chirp and beam current profile of those bunches can be reconstructed. This method is demonstrated through particle-in-cell simulations and experiment.

  4. Wakefield and RF Kicks Due to Coupler Asymmetry in TESLA-Type Accelerating Cavities

    International Nuclear Information System (INIS)

    Bane, K

    2008-01-01

    In a future linear collider, such as the International Linear Collider (ILC), trains of high current, low emittance bunches will be accelerated in a linac before colliding at the interaction point. Asymmetries in the accelerating cavities of the linac will generate fields that will kick the beam transversely and degrade the beam emittance and thus the collider performance. In the main linac of the ILC, which is filled with TESLA-type superconducting cavities, it is the fundamental (FM) and higher mode (HM) couplers that are asymmetric and thus the source of such kicks. The kicks are of two types: one, due to (the asymmetry in) the fundamental RF fields and the other, due to transverse wakefields that are generated by the beam even when it is on axis. In this report we calculate the strength of these kicks and estimate their effect on the ILC beam. The TESLA cavity comprises nine cells, one HM coupler in the upstream end, and one (identical, though rotated) HM coupler and one FM coupler in the downstream end (for their shapes and location see Figs. 1, 2) [1]. The cavity is 1.1 m long, the iris radius 35 mm, and the coupler beam pipe radius 39 mm. Note that the couplers reach closer to the axis than the irises, down to a distance of 30 mm

  5. Sapphire capillaries for laser-driven wakefield acceleration in plasma. Fs-laser micromachining and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Schwinkendorf, Jan-Patrick

    2012-08-15

    Plasma wakefields are a promising approach for the acceleration of electrons with ultrahigh (10 to 100 GV/m) electric fields. Nowadays, high-intensity laser pulses are routinely utilized to excite these large-amplitude plasma waves. However, several detrimental effects such as laser diffraction, electron-wake dephasing and laser depletion may terminate the acceleration process. Two of these phenomena can be mitigated or avoided by the application of capillary waveguides, e.g. fabricated out of sapphire for longevity. Capillaries may compensate for laser diffraction like a fiber and allow for the creation of tapered gas-density profiles working against the dephasing between the accelerating wave and the particles. Additionally, they offer the possibility of controlled particle injection. This thesis is reporting on the set up of a laser for fs-micromachining of capillaries of almost arbitrary shapes and a test stand for density-profile characterization. These devices will permit the creation of tailored gas-density profiles for controlled electron injection and acceleration inside plasma.

  6. Calculation of Wakefields and Higher Order Modes for the New Design of the Vacuum Chamber of the ALICE Experiment for the HL-LHC

    CERN Document Server

    Wanzenberg, Rainer; CERN. Geneva. ATS Department

    2016-01-01

    The High Luminosity Large Hadron Collider (HL-LHC) project was started with the goal to extend the discovery potential of the Large Hadron Collider (LHC). The HL-LHC study implies also an upgraded dimensions of the ALICE beam pipe. The trapped monopole and dipole Higher Order Modes (HOMs) and the short range wakefields for the new design of the ALICE vacuum chamber were calculated with help of the computer codes MAFIA and ECHO2D. The results of the short range wakefields calculations and the HOMs calculations for the ALICE vacuum chamber with new dimensions are presented in this report. The short range wakefields are presented in terms of longitudinal and transverse wake potentials and also in terms of loss and kick parameters. The frequency, the loss parameter, the R/Q and the Qvalues and also power loss parameters are presented as result of the HOMs calculations and can be converted into impedance values.

  7. Limitation on the accelerating gradient of a wakefield excited by an ultrarelativistic electron beam in rubidium plasma

    Directory of Open Access Journals (Sweden)

    N. Vafaei-Najafabadi

    2016-10-01

    Full Text Available We have investigated the viability of using plasmas formed by ionization of high Z, low ionization potential element rubidium (Rb for beam-driven plasma wakefield acceleration. The Rb vapor column confined by argon (Ar buffer gas was used to reduce the expected limitation on the beam propagation length due to head erosion that was observed previously when a lower Z but higher ionization potential lithium vapor was used. However, injection of electrons into the wakefield due to ionization of Ar buffer gas and nonuniform ionization of Rb^{1+} to Rb^{2+} was a possible concern. In this paper we describe experimental results and the supporting simulations which indicate that such ionization of Ar and Rb^{1+} in the presence of combined fields of the beam and the wakefield inside the wake does indeed occur. Some of this charge accumulates in the accelerating region of the wake leading to the reduction of the electric field—an effect known as beam loading. The beam-loading effect is quantified by determining the average transformer ratio ⟨R⟩ which is the maximum energy gained divided by the maximum energy lost by the electrons in the bunch used to produce the wake. ⟨R⟩ is shown to depend on the propagation length and the quantity of the accumulated charge, indicating that the distributed injection of secondary Rb electrons is the main cause of beam loading in this experiment. The average transformer ratio is reduced from 1.5 to less than 1 as the excess charge from secondary ionization increased from 100 to 700 pC. The simulations show that while the decelerating field remains constant, the accelerating field is reduced from its unloaded value of 82 to 46  GeV/m due to this distributed injection of dark current into the wake.

  8. Study of the Betatron and Compton X-ray sources produced in laser wakefield acceleration of electrons

    International Nuclear Information System (INIS)

    Ferri, Julien

    2016-01-01

    An ultra-short and ultra-intense laser pulse propagating in a low-density gas can accelerate in its wake a part of the electrons ionized from the gas to relativistic energies of a few hundreds of MeV over distances of a few millimeters only. During their acceleration, as a consequence of their transverse motion, these electrons emit strongly collimated X-rays in the forward direction, which are called betatron radiations. The characteristics of this source turn it into an interesting tool for high-resolution imagery.In this thesis, we explore three different axis to work on this source using simulations on the Particles-In-Cells codes CALDER and CALDER-Circ. We first study the creation of a betatron X-ray source with kilo-joule and pico-second laser pulses, for which duration and energy are then much higher than usual in this domain. In spite of the unusual laser parameters, we show that X-ray sources can still be generated, furthermore in two different regimes.In a second study, the generally observed discrepancies between experiments and simulations are investigated. We show that the use of realistic laser profiles instead of Gaussian ones in the simulations strongly degrades the performances of the laser-plasma accelerator and of the betatron source. Additionally, this leads to a better qualitative and quantitative agreement with the experiment. Finally, with the aim of improving the X-ray emission, we explore several techniques based on the manipulation of the plasma density profile used for acceleration. We find that both the use of a transverse gradient and of a density step increases the amplitude of the electrons transverse motions, and then increases the radiated energy. Alternatively, we show that this goal can also be achieved through the transition from a laser wakefield regime to a plasma wakefield regime induced by an increase of the density. The laser wakefield optimizes the electron acceleration whereas the plasma wakefield favours the X

  9. Electron diffraction using ultrafast electron bunches from a laser-wakefield accelerator at kHz repetition rate

    Science.gov (United States)

    He, Z.-H.; Thomas, A. G. R.; Beaurepaire, B.; Nees, J. A.; Hou, B.; Malka, V.; Krushelnick, K.; Faure, J.

    2013-02-01

    We show that electron bunches in the 50-100 keV range can be produced from a laser wakefield accelerator using 10 mJ, 35 fs laser pulses operating at 0.5 kHz. It is shown that using a solenoid magnetic lens, the electron bunch distribution can be shaped. The resulting transverse and longitudinal coherence is suitable for producing diffraction images from a polycrystalline 10 nm aluminum foil. The high repetition rate, the stability of the electron source, and the fact that its uncorrelated bunch duration is below 100 fs make this approach promising for the development of sub-100 fs ultrafast electron diffraction experiments.

  10. Electron diffraction using ultrafast electron bunches from a laser-wakefield accelerator at kHz repetition rate

    Energy Technology Data Exchange (ETDEWEB)

    He, Z.-H.; Thomas, A. G. R.; Nees, J. A.; Hou, B.; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48106-2099 (United States); Beaurepaire, B.; Malka, V.; Faure, J. [Laboratoire d' Optique Appliquee, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)

    2013-02-11

    We show that electron bunches in the 50-100 keV range can be produced from a laser wakefield accelerator using 10 mJ, 35 fs laser pulses operating at 0.5 kHz. It is shown that using a solenoid magnetic lens, the electron bunch distribution can be shaped. The resulting transverse and longitudinal coherence is suitable for producing diffraction images from a polycrystalline 10 nm aluminum foil. The high repetition rate, the stability of the electron source, and the fact that its uncorrelated bunch duration is below 100 fs make this approach promising for the development of sub-100 fs ultrafast electron diffraction experiments.

  11. Wakefield excitation by a sequence of relativistic electron bunches in dielectric waveguides of rectangular cross-section of various configurations

    International Nuclear Information System (INIS)

    Kiselev, V.A.; Linnik, A.F.; Mirnyj, V.I.; Onishchenko, I.N.; Sotnikov, G.V.; Uskov, V.V.

    2008-01-01

    The possibility to enhance the efficiency of wake wave excitation in dielectric waveguides of rectangular cross-section was investigated by increase of electron bunches coupling with excited wakefield that was achieved by decrease of transit channel cross-section. At that for each configuration the required changes of dielectric plates size were made to for maintain the coincidence concurrence of bunch repetition frequency and frequency of the principal transverse mode of the corresponding dielectric waveguide. It is established, the decrease of transit channel leading to essential changing of topography of total field excited wake wave

  12. Temporal dynamics of the longitudinal bunch profile in a laser wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Heigoldt, Matthias

    2017-05-19

    This thesis deals with the temporal characterisation of electron bunches produced by a laser plasma accelerator. In the so-called laser wakefield acceleration (LWFA) scheme, an ultra-short high-intensity laser pulse excites a plasma wave, which can sustain accelerating electric fields of several hundred GV/m, thus exceeding the fields attainable by current state-of-the-art radio frequency (RF) accelerators by four orders of magnitude, offering the prospect of downsizing both the size and cost of such machines. Furthermore, by intrinsically confining the accelerated electron beam to the μm-scale size of the plasma wave, LWFAs provide ultra-short and highly brilliant beams, sparking great scientific interest for their application as a driver for compact sources of ultra-short X-ray pulses, e.g. Thomson-scattering, betatron sources or table-top free-electron lasers (FELs). The bunch profile is an important quantity for the application of these sources. With particular regard to the envisioned table-top FELs, it also determines the available peak current, an import input parameter for an appropriate undulator design that is optimized to support the self-amplified spontaneous emission (SASE) process. The experiments presented in this thesis comprise the measurement of the temporal profile of electron bunches produced by LWFA and further investigation of the evolution of the temporal profile in dependence of the acceleration distance and the plasma density. By measuring the intensity spectrum of coherent transition radiation (CTR) emitted by LWFA-driven electron bunches in the frequency domain, the experiments allow a reconstruction of the longitudinal bunch profiles with unprecedented resolution. Compared to earlier work, a key improvement is the single-shot coverage of a broadband spectral range of more than four octaves, which yields a time resolution of the reconstructed bunch profile in the sub-femtosecond region. This work further inspired the development of a new

  13. Temporal dynamics of the longitudinal bunch profile in a laser wakefield accelerator

    International Nuclear Information System (INIS)

    Heigoldt, Matthias

    2017-01-01

    This thesis deals with the temporal characterisation of electron bunches produced by a laser plasma accelerator. In the so-called laser wakefield acceleration (LWFA) scheme, an ultra-short high-intensity laser pulse excites a plasma wave, which can sustain accelerating electric fields of several hundred GV/m, thus exceeding the fields attainable by current state-of-the-art radio frequency (RF) accelerators by four orders of magnitude, offering the prospect of downsizing both the size and cost of such machines. Furthermore, by intrinsically confining the accelerated electron beam to the μm-scale size of the plasma wave, LWFAs provide ultra-short and highly brilliant beams, sparking great scientific interest for their application as a driver for compact sources of ultra-short X-ray pulses, e.g. Thomson-scattering, betatron sources or table-top free-electron lasers (FELs). The bunch profile is an important quantity for the application of these sources. With particular regard to the envisioned table-top FELs, it also determines the available peak current, an import input parameter for an appropriate undulator design that is optimized to support the self-amplified spontaneous emission (SASE) process. The experiments presented in this thesis comprise the measurement of the temporal profile of electron bunches produced by LWFA and further investigation of the evolution of the temporal profile in dependence of the acceleration distance and the plasma density. By measuring the intensity spectrum of coherent transition radiation (CTR) emitted by LWFA-driven electron bunches in the frequency domain, the experiments allow a reconstruction of the longitudinal bunch profiles with unprecedented resolution. Compared to earlier work, a key improvement is the single-shot coverage of a broadband spectral range of more than four octaves, which yields a time resolution of the reconstructed bunch profile in the sub-femtosecond region. This work further inspired the development of a new

  14. Simulation study of the sub-terawatt laser wakefield acceleration operated in self-modulated regime

    Science.gov (United States)

    Hsieh, C.-Y.; Lin, M.-W.; Chen, S.-H.

    2018-02-01

    Laser wakefield acceleration (LWFA) can be accomplished by introducing a sub-terawatt (TW) laser pulse into a thin, high-density gas target. In this way, the self-focusing effect and the self-modulation that happened on the laser pulse produce a greatly enhanced laser peak intensity that can drive a nonlinear plasma wave to accelerate electrons. A particle-in-cell model is developed to study sub-TW LWFA when a 0.6-TW laser pulse interacts with a dense hydrogen plasma. Gas targets having a Gaussian density profile or a flat-top distribution are defined for investigating the properties of sub-TW LWFA when conducting with a gas jet or a gas cell. In addition to using 800-nm laser pulses, simulations are performed with 1030-nm laser pulses, as they represent a viable approach to realize the sub-TW LWFA driven by high-frequency, diode-pumped laser systems. The peak density which allows the laser peak power PL˜2 Pc r of self-focusing critical power is favourable for conducting sub-TW LWFA. Otherwise, an excessively high peak density can induce an undesired filament effect which rapidly disintegrates the laser field envelope and violates the process of plasma wave excitation. The plateau region of a flat-top density distribution allows the self-focusing and the self-modulation of the laser pulse to develop, from which well-established plasma bubbles can be produced to accelerate electrons. The process of electron injection is complicated in such high-density plasma conditions; however, increasing the length of the plateau region represents a straightforward method to realize the injection and acceleration of electrons within the first bubble, such that an improved LWFA performance can be accomplished.

  15. Injection of electrons by colliding laser pulses in a laser wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Hansson, M., E-mail: martin.hansson@fysik.lth.se; Aurand, B.; Ekerfelt, H.; Persson, A.; Lundh, O.

    2016-09-01

    To improve the stability and reproducibility of laser wakefield accelerators and to allow for future applications, controlling the injection of electrons is of great importance. This allows us to control the amount of charge in the beams of accelerated electrons and final energy of the electrons. Results are presented from a recent experiment on controlled injection using the scheme of colliding pulses and performed using the Lund multi-terawatt laser. Each laser pulse is split into two parts close to the interaction point. The main pulse is focused on a 2 mm diameter gas jet to drive a nonlinear plasma wave below threshold for self-trapping. The second pulse, containing only a fraction of the total laser energy, is focused to collide with the main pulse in the gas jet under an angle of 150°. Beams of accelerated electrons with low divergence and small energy spread are produced using this set-up. Control over the amount of accelerated charge is achieved by rotating the plane of polarization of the second pulse in relation to the main pulse. Furthermore, the peak energy of the electrons in the beams is controlled by moving the collision point along the optical axis of the main pulse, and thereby changing the acceleration length in the plasma. - Highlights: • Compact colliding pulse injection set-up used to produce low energy spread e-beams. • Beam charge controlled by rotating the polarization of injection pulse. • Peak energy controlled by point of collision to vary the acceleration length.

  16. Anonymous voting for multi-dimensional CV quantum system

    International Nuclear Information System (INIS)

    Shi Rong-Hua; Xiao Yi; Shi Jin-Jing; Guo Ying; Lee, Moon-Ho

    2016-01-01

    We investigate the design of anonymous voting protocols, CV-based binary-valued ballot and CV-based multi-valued ballot with continuous variables (CV) in a multi-dimensional quantum cryptosystem to ensure the security of voting procedure and data privacy. The quantum entangled states are employed in the continuous variable quantum system to carry the voting information and assist information transmission, which takes the advantage of the GHZ-like states in terms of improving the utilization of quantum states by decreasing the number of required quantum states. It provides a potential approach to achieve the efficient quantum anonymous voting with high transmission security, especially in large-scale votes. (paper)

  17. A broadband gamma-ray spectrometry using novel unfolding algorithms for characterization of laser wakefield-generated betatron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Jong Ho, E-mail: jhjeon07@ibs.re.kr; Nakajima, Kazuhisa, E-mail: naka115@dia-net.ne.jp; Pathak, Vishwa Bandhu; Cho, Myung Hoon; Yoo, Byung Ju; Shin, Kang Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Kim, Hyung Taek; Sung, Jae Hee; Lee, Seung Ku; Choi, Il Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Rhee, Yong Joo [Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Shin, Jung Hun; Jo, Sung Ha [Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Hojbota, Calin; Cho, Byeoung Ick; Nam, Chang Hee [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 500-712 (Korea, Republic of)

    2015-12-15

    We present a high-flux, broadband gamma-ray spectrometry capable of characterizing the betatron radiation spectrum over the photon energy range from 10 keV to 20 MeV with respect to the peak photon energy, spectral bandwidth, and unique discrimination from background radiations, using a differential filtering spectrometer and the unfolding procedure based on the Monte Carlo code GEANT4. These properties are experimentally verified by measuring betatron radiation from a cm-scale laser wakefield accelerator (LWFA) driven by a 1-PW laser, using a differential filtering spectrometer consisting of a 15-filter and image plate stack. The gamma-ray spectra were derived by unfolding the photostimulated luminescence (PSL) values recorded on the image plates, using the spectrometer response matrix modeled with the Monte Carlo code GEANT4. The accuracy of unfolded betatron radiation spectra was assessed by unfolding the test PSL data simulated with GEANT4, showing an ambiguity of less than 20% and clear discrimination from the background radiation with less than 10%. The spectral analysis of betatron radiation from laser wakefield-accelerated electron beams with energies up to 3 GeV revealed radiation spectra characterized by synchrotron radiation with the critical photon energy up to 7 MeV. The gamma-ray spectrometer and unfolding method presented here facilitate an in-depth understanding of betatron radiation from LWFA process and a novel radiation source of high-quality photon beams in the MeV regime.

  18. A bremsstrahlung gamma-ray source based on stable ionization injection of electrons into a laser wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Döpp, A., E-mail: andreas.doepp@polytechnique.edu [LOA, ENSTA ParisTech, CNRS, École polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France); Centro de Laseres Pulsados, Parque Cientfico, 37185 Villamayor, Salamanca (Spain); Guillaume, E.; Thaury, C.; Lifschitz, A. [LOA, ENSTA ParisTech, CNRS, École polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France); Sylla, F. [SourceLAB SAS, 86 rue de Paris, 91400 Orsay (France); Goddet, J-P.; Tafzi, A.; Iaquanello, G.; Lefrou, T.; Rousseau, P. [LOA, ENSTA ParisTech, CNRS, École polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France); Conejero, E.; Ruiz, C. [Departamento de Física Aplicada, Universidad de Salamanca, Plaza de laMerced s/n, 37008 Salamanca (Spain); Ta Phuoc, K.; Malka, V. [LOA, ENSTA ParisTech, CNRS, École polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France)

    2016-09-11

    Laser wakefield acceleration permits the generation of ultra-short, high-brightness relativistic electron beams on a millimeter scale. While those features are of interest for many applications, the source remains constraint by the poor stability of the electron injection process. Here we present results on injection and acceleration of electrons in pure nitrogen and argon. We observe stable, continuous ionization-induced injection of electrons into the wakefield for laser powers exceeding a threshold of 7 TW. The beam charge scales approximately with the laser energy and is limited by beam loading. For 40 TW laser pulses we measure a maximum charge of almost 1 nC per shot, originating mostly from electrons of less than 10 MeV energy. The relatively low energy, the high charge and its stability make this source well-suited for applications such as non-destructive testing. Hence, we demonstrate the production of energetic radiation via bremsstrahlung conversion at 1 Hz repetition rate. In accordance with GEANT4 Monte-Carlo simulations, we measure a γ-ray source size of less than 100 μm for a 0.5 mm tantalum converter placed at 2 mm from the accelerator exit. Furthermore we present radiographs of image quality indicators.

  19. Instant OpenCV for iOS

    CERN Document Server

    Kornyakov, Kirill

    2013-01-01

    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. This book uses a very practical approach, with each recipe and their associated sample projects or examples focusing on a particular aspect of the technology.This book is intended for OpenCV developers who are interested in porting their applications to the iOS platform. Basic experience with OpenCV, computer vision, Objective C, and other iOS tools is encouraged.

  20. Self-Resonant Plasma Wake-Field Excitation by a Laser-Pulse with a Steep Leading-Edge for Particle-Acceleration

    NARCIS (Netherlands)

    Goloviznin, V. V.; van Amersfoort, P. W.

    1995-01-01

    The self-modulational instability of a relatively long laser pulse with a power close to or less than the critical power for relativistic self-focusing in plasma is considered. Strong wake-field excitation occurs as the result of a correlated transverse and longitudinal evolution of the pulse. The

  1. Plasma wakefields driven by an incoherent combination of laser pulses: a path towards high-average power laser-plasma accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Benedetti, C.; Schroeder, C.B.; Esarey, E.; Leemans, W.P.

    2014-05-01

    he wakefield generated in a plasma by incoherently combining a large number of low energy laser pulses (i.e.,without constraining the pulse phases) is studied analytically and by means of fully-self-consistent particle-in-cell simulations. The structure of the wakefield has been characterized and its amplitude compared with the amplitude of the wake generated by a single (coherent) laser pulse. We show that, in spite of the incoherent nature of the wakefield within the volume occupied by the laser pulses, behind this region the structure of the wakefield can be regular with an amplitude comparable or equal to that obtained from a single pulse with the same energy. Wake generation requires that the incoherent structure in the laser energy density produced by the combined pulses exists on a time scale short compared to the plasma period. Incoherent combination of multiple laser pulses may enable a technologically simpler path to high-repetition rate, high-average power laser-plasma accelerators and associated applications.

  2. Ensacamento de frutos de pereira cv. Housui Bagging of nashi pear cv. Housui

    Directory of Open Access Journals (Sweden)

    Ivan Dagoberto Faoro

    2004-04-01

    Full Text Available Foi avaliada a qualidade de frutos de pêra japonesa cv. Housui (Pyrus pyrifolia var. culta ensacados com diferentes tipos de sacos de papel e em duas épocas: 34 e 83 dias após a florada. O ensacamento não influenciou na firmeza, no teor de sólidos solúveis totais e no peso médio dos frutos. Sacos vermelhos não induziram aumento do pH da polpa, mas o uso de sacos duplos, sacos marrons, sacos de papel kraft marrons e sacos de pipoca brancos aumentaram significativamente o pH. Ao buscar-se maior precocidade de colheita, os melhores resultados foram obtidos com o uso de sacos pequenos de papel manteiga aos 34 dias após a floração e o uso de sacos grandes duplos ou sacos grandes marrons, 83 dias após a plena floração. O ensacamento 34 dias após a plena floração, com sacos grandes de papel duplo de cor marrom ou sacos de papel kraft marrons, ou ainda o uso de sacos pequenos parafinados transparentes de papel manteiga, aos 34 dias, seguidos pela colocação, aos 83 dias, dos dois tipos de sacos grandes citados anteriormente, resultaram em frutos de melhor qualidade externa (película de coloração homogênea e mais clara, lisa e com lenticelas pouco salientes. O uso de sacos vermelhos de papel manteiga e de sacos de pipoca brancos, com ou sem ensacamento prévio com sacos pequenos de papel manteiga parafinado, não resultaram em melhoria substancial da qualidade externa do fruto.The fruit quality of Nashi pears cv. Housui (Pyrus pyrifolia var. culta have been evaluated after bagging with different paper bags at two bagging dates: 34 and 83 days after full bloom. The bagging did not affect the fruit firmness, the total soluble solids and the average fruit weight. Red bags did not affect the pH of the fruit flesh. However the fruit bagged with double bags of brown color, brown kraft paper and white popcorn paper increased the pH. In order to harvest precociously, the use of small transparent paraffin paper bags 34 days after full bloom

  3. Dose properties of x-ray beams produced by laser-wakefield-accelerated electrons

    International Nuclear Information System (INIS)

    Kainz, K K; Hogstrom, K R; Antolak, J A; Almond, P R; Bloch, C D

    2005-01-01

    Given that laser wakefield acceleration (LWFA) has been demonstrated experimentally to accelerate electron beams to energies beyond 25 MeV, it is reasonable to assess the ability of existing LWFA technology to compete with conventional radiofrequency linear accelerators in producing electron and x-ray beams for external-beam radiotherapy. We present calculations of the dose distributions (off-axis dose profiles and central-axis depth dose) and dose rates of x-ray beams that can be produced from electron beams that are generated using state-of-the-art LWFA. Subsets of an LWFA electron energy distribution were propagated through the treatment head elements (presuming an existing design for an x-ray production target and flattening filter) implemented within the EGSnrc Monte Carlo code. Three x-ray energy configurations (6 MV, 10 MV and 18 MV) were studied, and the energy width ΔE of the electron-beam subsets varied from 0.5 MeV to 12.5 MeV. As ΔE increased from 0.5 MeV to 4.5 MeV, we found that the off-axis and central-axis dose profiles for x-rays were minimally affected (to within about 3%), a result slightly different from prior calculations of electron beams broadened by scattering foils. For ΔE of the order of 12 MeV, the effect on the off-axis profile was of the order of 10%, but the central-axis depth dose was affected by less than 2% for depths in excess of about 5 cm beyond d max . Although increasing ΔE beyond 6.5 MeV increased the dose rate at d max by more than 10 times, the absolute dose rates were about 3 orders of magnitude below those observed for LWFA-based electron beams at comparable energies. For a practical LWFA-based x-ray device, the beam current must be increased by about 4-5 orders of magnitude. (note)

  4. Time domain numerical calculations of the short electron bunch wakefields in resistive structures

    Energy Technology Data Exchange (ETDEWEB)

    Tsakanian, Andranik

    2010-10-15

    The acceleration of electron bunches with very small longitudinal and transverse phase space volume is one of the most actual challenges for the future International Linear Collider and high brightness X-Ray Free Electron Lasers. The exact knowledge on the wake fields generated by the ultra-short electron bunches during its interaction with surrounding structures is a very important issue to prevent the beam quality degradation and to optimize the facility performance. The high accuracy time domain numerical calculations play the decisive role in correct evaluation of the wake fields in advanced accelerators. The thesis is devoted to the development of a new longitudinally dispersion-free 3D hybrid numerical scheme in time domain for wake field calculation of ultra short bunches in structures with walls of finite conductivity. The basic approaches used in the thesis to solve the problem are the following. For materials with high but finite conductivity the model of the plane wave reflection from a conducting half-space is used. It is shown that in the conductive half-space the field components perpendicular to the interface can be neglected. The electric tangential component on the surface contributes to the tangential magnetic field in the lossless area just before the boundary layer. For high conducting media, the task is reduced to 1D electromagnetic problem in metal and the so-called 1D conducting line model can be applied instead of a full 3D space description. Further, a TE/TM (''transverse electric - transverse magnetic'') splitting implicit numerical scheme along with 1D conducting line model is applied to develop a new longitudinally dispersion-free hybrid numerical scheme in the time domain. The stability of the new hybrid numerical scheme in vacuum, conductor and bound cell is studied. The convergence of the new scheme is analyzed by comparison with the well-known analytical solutions. The wakefield calculations for a number of

  5. Plant regeneration of Brassica oleracea subsp. italica (Broccoli) CV ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... Department of Agriculture Technology, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul. Ehsan, Malaysia. Accepted 20 March, 2009. Hypocotyls and shoot tips were used as explants in in vitro plant regeneration of broccoli (Brassica oleracea subsp.italica) cv. Green Marvel.

  6. Bremsstrahlung hard x-ray source driven by an electron beam from a self-modulated laser wakefield accelerator

    Science.gov (United States)

    Lemos, N.; Albert, F.; Shaw, J. L.; Papp, D.; Polanek, R.; King, P.; Milder, A. L.; Marsh, K. A.; Pak, A.; Pollock, B. B.; Hegelich, B. M.; Moody, J. D.; Park, J.; Tommasini, R.; Williams, G. J.; Chen, Hui; Joshi, C.

    2018-05-01

    An x-ray source generated by an electron beam produced using a Self-Modulated Laser Wakefield Accelerator (SM-LWFA) is explored for use in high energy density science facilities. By colliding the electron beam, with a maximum energy of 380 MeV, total charge of >10 nC and a divergence of 64 × 100 mrad, from a SM-LWFA driven by a 1 ps 120 J laser, into a high-Z foil, an x/gamma-ray source was generated. A broadband bremsstrahlung energy spectrum with temperatures ranging from 0.8 to 2 MeV was measured with an almost 2 orders of magnitude flux increase when compared with other schemes using LWFA. GEANT4 simulations were done to calculate the source size and divergence.

  7. Stable electron beams from laser wakefield acceleration with few-terawatt driver using a supersonic air jet

    Science.gov (United States)

    Boháček, K.; Kozlová, M.; Nejdl, J.; Chaulagain, U.; Horný, V.; Krůs, M.; Ta Phuoc, K.

    2018-03-01

    The generation of stable electron beams produced by the laser wakefield acceleration mechanism with a few-terawatt laser system (600 mJ, 50 fs) in a supersonic synthetic air jet is reported and the requirements necessary to build such a stable electron source are experimentally investigated in conditions near the bubble regime threshold. The resulting electron beams have stable energies of (17.4 ± 1.1) MeV and an energy spread of (13.5 ± 1.5) MeV (FWHM), which has been achieved by optimizing the properties of the supersonic gas jet target for the given laser system. Due to the availability of few-terawatt laser systems in many laboratories around the world these stable electron beams open possibilities for applications of this type of particle source.

  8. Photoinjector optimization using a derivative-free, model-based trust-region algorithm for the Argonne Wakefield Accelerator

    Science.gov (United States)

    Neveu, N.; Larson, J.; Power, J. G.; Spentzouris, L.

    2017-07-01

    Model-based, derivative-free, trust-region algorithms are increasingly popular for optimizing computationally expensive numerical simulations. A strength of such methods is their efficient use of function evaluations. In this paper, we use one such algorithm to optimize the beam dynamics in two cases of interest at the Argonne Wakefield Accelerator (AWA) facility. First, we minimize the emittance of a 1 nC electron bunch produced by the AWA rf photocathode gun by adjusting three parameters: rf gun phase, solenoid strength, and laser radius. The algorithm converges to a set of parameters that yield an emittance of 1.08 μm. Second, we expand the number of optimization parameters to model the complete AWA rf photoinjector (the gun and six accelerating cavities) at 40 nC. The optimization algorithm is used in a Pareto study that compares the trade-off between emittance and bunch length for the AWA 70MeV photoinjector.

  9. Colliding pulse injection experiments in non-collinear geometry for controlled laser plasma wakefield acceleration of electrons

    International Nuclear Information System (INIS)

    Toth, Carl B.; Esarey, Eric H.; Geddes, Cameron G.R.; Leemans, Wim P.; Nakamura, Kei; Panasenko, Dmitriy; Schroeder, Carl B.; Bruhwiler, D.; Cary, J.R.

    2007-01-01

    An optical injection scheme for a laser-plasma based accelerator which employs a non-collinear counter-propagating laser beam to push background electrons in the focusing and acceleration phase via ponderomotive beat with the trailing part of the wakefield driver pulse is discussed. Preliminary experiments were performed using a drive beam of a 0 = 2.6 and colliding beam of a 1 = 0.8 both focused on the middle of a 200 mu m slit jet backed with 20 bar, which provided ∼ 260 mu m long gas plume. The enhancement in the total charge by the colliding pulse was observed with sharp dependence on the delay time of the colliding beam. Enhancement of the neutron yield was also measured, which suggests a generation of electrons above 10 MeV

  10. Analisis Kinerja CV. Fabamus Famili Utama Semarang Dengan Balanced Scorecard

    OpenAIRE

    Permata, Nilla Mega; Nugraha, Hari Susanta; Nurseto, Sendhang

    2014-01-01

    A method of measuring the performance of the company to assist in knowing the health condition of the company itself. The study was conducted on the CV. Fabamus First Family with Balanced Scorecard approach to measuring through four perspectives: financial perspective, customer perspective, internal business process perspective and learning and growth perspectives. In the financial aspects of performance measurement with a weight of 70%, 10% customer perspective, internal business process per...

  11. STRATEGI PEMASARAN PRODUK DIGITAL PRINTING PADA CV. FNB DIGITAL JAMBI

    OpenAIRE

    Yuniarti, Yenni; Mauliana, Sarah

    2012-01-01

    CV. Digital FNB is one of the companies that involved in Digital Printing business. Based on survey in the middle of 2011-2012, there are 31 digital printing businesses in the city of Jambi. In order to examine the marketing stratey implemented, descriptive study has been conducted, uses interview, observation, and documentation as instruments. The strategy that observed in this study consist of marketing strategy including market segmentation, targeting, product strategy, pricing strategy, ...

  12. Applications in Foreign Currency Prima CV Ellindo Money Changer

    OpenAIRE

    Wisnu Sutrisno; Ire Puspa Wardhani, Skom, MMSI

    2004-01-01

    This explains the scientific writing about the design of application programs forforeign currency transactions by using Visual Basic 6.0 programming language.In scientific writing database is also used by Visual Data Manager (VisData)integrated in Visual Basic 6.0 program itself. Consists of three tables namelyCurrency,Customer and Transaction.In the end application program for foreign currency transactions will be applied to theCV. Prima Ellindo Money Changer for ease in performing activitie...

  13. The draft genome of Corchorus olitorius cv. JRO-524 (Navin

    Directory of Open Access Journals (Sweden)

    Debabrata Sarkar

    2017-06-01

    Full Text Available Here, we present the draft genome (377.3 Mbp of Corchorus olitorious cv. JRO-524 (Navin, which is a leading dark jute variety developed from a cross between African (cv. Sudan Green and indigenous (cv. JRO-632 types. We predicted from the draft genome a total of 57,087 protein-coding genes with annotated functions. We identified a large number of 1765 disease resistance-like and defense response genes in the jute genome. The annotated genes showed the highest sequence similarities with that of Theobroma cacao followed by Gossypium raimondii. Seven chromosome-scale genetically anchored pseudomolecules were constructed with a total size of 8.53 Mbp and used for synteny analyses with the cocoa and cotton genomes. Like other plant species, gypsy and copia retrotransposons were the most abundant classes of repeat elements in jute. The raw data of our study are available in SRA database of NCBI with accession number SRX1506532. The genome sequence has been deposited at DDBJ/EMBL/GenBank under the accession LLWS00000000, and the version described in this paper will be the first version (LLWS01000000.

  14. Shaping of pulses in optical grating-based laser systems for optimal control of electrons in laser plasma wake-field accelerator

    International Nuclear Information System (INIS)

    Toth, Cs.; Faure, J.; Geddes, C.G.R.; Tilborg, J. van; Leemans, W.P.

    2003-01-01

    In typical chirped pulse amplification (CPA) laser systems, scanning the grating separation in the optical compressor causes the well know generation of linear chirp of frequency vs. time in a laser pulse, as well as a modification of all the higher order phase terms. By setting the compressor angle slightly different from the optimum value to generate the shortest pulse, a typical scan around this value will produce significant changes to the pulse shape. Such pulse shape changes can lead to significant differences in the interaction with plasmas such as used in laser wake-field accelerators. Strong electron yield dependence on laser pulse shape in laser plasma wake-field electron acceleration experiments have been observed in the L'OASIS Lab of LBNL [1]. These experiments show the importance of pulse skewness parameter, S, defined here on the basis of the ratio of the ''head-width-half-max'' (HWHM) and the ''tail-width-halfmax'' (TWHM), respectively

  15. Improvements to laser wakefield accelerated electron beam stability, divergence, and energy spread using three-dimensional printed two-stage gas cell targets

    International Nuclear Information System (INIS)

    Vargas, M.; Schumaker, W.; He, Z.-H.; Zhao, Z.; Behm, K.; Chvykov, V.; Hou, B.; Krushelnick, K.; Maksimchuk, A.; Yanovsky, V.; Thomas, A. G. R.

    2014-01-01

    High intensity, short pulse lasers can be used to accelerate electrons to ultra-relativistic energies via laser wakefield acceleration (LWFA) [T. Tajima and J. M. Dawson, Phys. Rev. Lett. 43, 267 (1979)]. Recently, it was shown that separating the injection and acceleration processes into two distinct stages could prove beneficial in obtaining stable, high energy electron beams [Gonsalves et al., Nat. Phys. 7, 862 (2011); Liu et al., Phys. Rev. Lett. 107, 035001 (2011); Pollock et al., Phys. Rev. Lett. 107, 045001 (2011)]. Here, we use a stereolithography based 3D printer to produce two-stage gas targets for LWFA experiments on the HERCULES laser system at the University of Michigan. We demonstrate substantial improvements to the divergence, pointing stability, and energy spread of a laser wakefield accelerated electron beam compared with a single-stage gas cell or gas jet target

  16. Improvements to laser wakefield accelerated electron beam stability, divergence, and energy spread using three-dimensional printed two-stage gas cell targets

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, M.; Schumaker, W.; He, Z.-H.; Zhao, Z.; Behm, K.; Chvykov, V.; Hou, B.; Krushelnick, K.; Maksimchuk, A.; Yanovsky, V.; Thomas, A. G. R., E-mail: agrt@umich.edu [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-04-28

    High intensity, short pulse lasers can be used to accelerate electrons to ultra-relativistic energies via laser wakefield acceleration (LWFA) [T. Tajima and J. M. Dawson, Phys. Rev. Lett. 43, 267 (1979)]. Recently, it was shown that separating the injection and acceleration processes into two distinct stages could prove beneficial in obtaining stable, high energy electron beams [Gonsalves et al., Nat. Phys. 7, 862 (2011); Liu et al., Phys. Rev. Lett. 107, 035001 (2011); Pollock et al., Phys. Rev. Lett. 107, 045001 (2011)]. Here, we use a stereolithography based 3D printer to produce two-stage gas targets for LWFA experiments on the HERCULES laser system at the University of Michigan. We demonstrate substantial improvements to the divergence, pointing stability, and energy spread of a laser wakefield accelerated electron beam compared with a single-stage gas cell or gas jet target.

  17. Laser wakefield excitation and measurement on a femtosecond time scale: Theory and experiment. Progress report, September 1, 1993--August 31, 1994

    International Nuclear Information System (INIS)

    Tajima, T.; Downer, M.

    1994-03-01

    This is a progress report describing work on laser generated wakefields, which can be applied to particle acceleration. The authors have carried out simulation studies in one and two dimensions, and experimental studies of the generation of such fields. The authors also report on the propagation studies of femtosecond laser pulses in atmospheric density gases, and work on developing such high power laser sources, with well controlled pointing and spectral characteristics. The project has involved collaboration with Japanese and Russian researchers

  18. Analisis Daya Saing untuk Meningkatkan Kualitas Layanan terhadap Pelanggan dengan Pendekatan CRM di CV. BLITZSPOT

    Directory of Open Access Journals (Sweden)

    Suryadi Muhammad

    2017-04-01

    Full Text Available CV. Blitzspot adalah perusahaan yang bergerak di bidang jasa penyediaan layanan internet (internet service provider, yang berkantor pusat di Komplek Padasuka Indah Ruko Blok A-1, Cimahi, Jawa Barat. Berdasarkan hasil wawancara dan hasil observasi pada data transaksi CV. Blitzspot, konsumen CV. Blitzspot yang melakukan transaksi tiap tahunnya selalu berkurang, hal ini dikarenakan konsumen sering membandingkan layanan-layanan yang ditawarkan oleh para pesaing CV. Blitzspot. Bila permasalahan tersebut belum teratasi, konsumen CV. Blitzspot akan menurun tiap tahunnya dan akan selalu berpindah ke pesaing CV. Blitzspot. Direktur Utama CV. Blitzspot ingin menganalisis daya saing untuk menentukan layanan-layanan yang akan diberikan kepada pelanggan CV. Blitzspot dan penentuan strategi untuk mempertahankan konsumen CV. Blitzspot.  Metode Analisis daya saing yang digunakan adalah Model Analisis Berlian Porter dan Metode Pengelompokkan Pelanggan yang digunakan adalah Metode LRFM. Berdasarkan hasil pengujian dan pembahasan yang telah dibuat, maka dapat ditarik kesimpulan bahwa Direktur Utama dapat menganalisis daya saing CV. Blitzspot dengan menggunakan Berlian Porter untuk meningkatkan kualitas layanan terhadap pelanggan CV. Blitzspot.

  19. Induction of single flower mutant in Hibiscus cv. 'Alipur Beauty'

    International Nuclear Information System (INIS)

    Banerji, B.K.; Datta, S.K.

    1986-01-01

    Stem cuttings of Hibicus cv. 'Alipur Beauty' were irradiated with 0, 1.0, 2.0 Krad of gamma rays in 60 Co source and planted just after irradiation. Data were recorded on days to sprout, number of sprouts, sprouting percentage, survival, plant height, leaf number and size, abnormal leaves and plants, floral abnormalities and induction of somatic mutations in flower colour/form. Some of the characters like plant height, leaf number, abnormal leaves and plants and leaf size were recorded after 60 and 120 days. 7 refs. (author)

  20. DETECTION OF MOTORCYCLISTS WITHOUT HELMET AND FINEPAYMENT USING OPEN CV

    OpenAIRE

    Stemy Simon, Divya Kumaran A.K.

    2018-01-01

    The helmet is the main safety equipment of motorcyclists, but many drivers do not use it. The main aim of this project is to construct an automatic detection of the motorcyclist without helmet from video using OpenCV library tools. If they are not wearing the helmet, the license plate of the motorcycle is focused automatically. By using Computer Vision technique we can detect and recognize the license plate number. We make the training set of different characters of different sizes. Based on ...

  1. Comparison of tracking algorithms implemented in OpenCV

    Directory of Open Access Journals (Sweden)

    Janku Peter

    2016-01-01

    Full Text Available Computer vision is very progressive and modern part of computer science. From scientific point of view, theoretical aspects of computer vision algorithms prevail in many papers and publications. The underlying theory is really important, but on the other hand, the final implementation of an algorithm significantly affects its performance and robustness. For this reason, this paper tries to compare real implementation of tracking algorithms (one part of computer vision problem, which can be found in the very popular library OpenCV. Moreover, the possibilities of optimizations are discussed.

  2. OpenCV 3.0 computer vision with Java

    CERN Document Server

    Baggio, Daniel Lélis

    2015-01-01

    If you are a Java developer, student, researcher, or hobbyist wanting to create computer vision applications in Java then this book is for you. If you are an experienced C/C++ developer who is used to working with OpenCV, you will also find this book very useful for migrating your applications to Java. All you need is basic knowledge of Java, with no prior understanding of computer vision required, as this book will give you clear explanations and examples of the basics.

  3. Alcohol and CV Health: Jekyll and Hyde J-Curves.

    Science.gov (United States)

    O'Keefe, Evan L; DiNicolantonio, James J; O'Keefe, James H; Lavie, Carl J

    2018-02-16

    A routine of light or moderate alcohol consumption (≤1 drink/day for women and 1 to 2 drinks/day for men) is associated with a lower risk for all-cause mortality, coronary artery disease (CAD), type 2 diabetes mellitus (T2D), heart failure (HF), and stroke. Conversely, heavy drinking, (>4 drinks/day) is associated with an increased risk for death and cardiovascular (CV) disease (CVD). Excessive alcohol intake trails behind only smoking and obesity among the 3 leading causes of premature deaths in the United States (US). Heavy alcohol use is a common cause of reversible hypertension (HTN), nonischemic dilated cardiomyopathy, atrial fibrillation (AF), and stroke (both ischemic and hemorrhagic). Among males aged 15 to 59 years, alcohol abuse is perhaps the leading cause of premature death. As such, the risk-to-benefit ratio of drinking is less favorable in younger individuals. A daily habit of light to moderate drinking is ideal for those who choose to consume alcohol regularly. Red wine in particular before or during the evening meal is linked with the best long-term CV outcomes. Most of the studies on alcohol and health are observational, and correlation does not prove causation. Health care professionals should not advise nondrinkers to begin drinking because of the paucity of randomized outcome data coupled with the potential for alcohol abuse even among seemingly low risk individuals. Copyright © 2017. Published by Elsevier Inc.

  4. Resistance selection on banana CV. Ambon Kuning Against Fusarium Wilt

    International Nuclear Information System (INIS)

    Sutarto, Ismiyarti; Meldia, Yeni; Jumjunidang

    1998-01-01

    This research was conducted in order to study the occurrence of mutation on irradiated plantlets and their resistance of plants of banana cv. Ambon Kuning against Fusarium wilt. Plantlets of banana cv. Ambon Kuning sized 5 cm were exposed to gamma rays at the doses 5 - 35 Gy intervals, then were subcultured for obtained M 1 V 5 plantlets. More over, the planlets were acclimatized and were planted in the field was already infected by Fasarium (f).culbense (FOC). The result indicated that irradiated plantlets of the doses 20 - 35 Gy were not able to survive up to 6 months after exposing to gamma rays. Abnormalities of M 1 V 5 plantlets originated from irradiated plantlets at the doses 10 and 15 Gy were shown on rossette plantlets with rigid and dark green leaves, and the formation of smooth mass morphologically shaped like calculus. The appearance of plant height and number of suckers of suckers of M 1 V 5 plants in the field was quite various. The number of survival plants after 8 moths planting was 8, 7, 15, and 28, respectively originated from untreated plants and irradiated plantlets at the doses 5, 10, and 15 Gy. After one year planting , only 2 plants were able to survive from irradiated plantlet at the dose 15 Gy. The plants could produce 27 plantlets obtained from culturing their shoot tips. Further study of these plantlets was needed in order create the stability of their resistance to FOC. (author)

  5. EN-CV during LS1: upgrade, consolidation, maintenance, operation

    International Nuclear Information System (INIS)

    Nonis, M.

    2012-01-01

    The Cooling and Ventilation (CV) Group in the Engineering Department (EN) will be heavily involved in several projects and activities during the long shutdown in 2013 and 2014 (LS1) within a time-frame limited to around twelve months. According to the requests received so far, most projects are related to the upgrade of users' equipment, consolidation work, and the construction of new plants. However, through the experience gained from the first years of the LHC run, some projects are also needed to adapt the existing installations to the new operating parameters. Some of these projects are presented hereafter, outlining the impact that they will have on operational working conditions or risks of breakdown. Among these projects we find: the PM32 raising pumps, the cooling of the CERN Control Center, R2E, the backup cooling towers for ATLAS and cryogenics, a thermosyphon for ATLAS, or new pumps in UWs. Finally, EN-CV activities during LS1 for maintenance, operation, and commissioning will be mentioned since they represent a major workload for the Group

  6. Perancangan Kemasan Transportasi Buah Jambu Air (Syzygium aqueum cv Camplong

    Directory of Open Access Journals (Sweden)

    Iswahyudi

    2015-04-01

    Full Text Available Jamboo cv Camplong was an exotic fruit from Sampang Indonesia which had high economic values. The quality of fresh Jamboo was greatly influenced by the types of packaging and ways of its transportation that affected its shelf life. The purpose of this research were designing a primary packaging and analyzing the quality of Jamboo cv Camplong after short transportation (from Sampang to Surabaya. Farmers used conventional packaging with capacity of 8.4 kg/box (dimension 478 mm x 146 mm x 354 mm. Based on theoretical packaging design showed that the flute BC cardboard (capacity 4.5 kg/box, dimension 357 mm x 217 mm x 216 mm with partition flute A cardboard. In fact, there was needed modification of the dimension (342 mm x 210 mm x 200 mm because of the fruits diameter (60-65 mm. This result did not change the efficiency usage of transportation space (91-95% and compression strength of box can support (7 boxes/ stack. The result showed that the mechanical damage after transportation were 20.87% for conventional packaging (as control and 7.70% for modification packaging design (packaging with partition.

  7. Pump depletion limited evolution of the relativistic plasma wave-front in a forced laser-wakefield accelerator

    International Nuclear Information System (INIS)

    Fang, F; Clayton, C E; Marsh, K A; Pak, A E; Ralph, J E; Joshi, C; Lopes, N C

    2009-01-01

    In a forced laser-wakefield accelerator experiment (Malka et al 2002 Science 298 1596) where the length of the pump laser pulse is a few plasma periods long, the leading edge of the laser pulse undergoes frequency downshifting and head erosion as the laser energy is transferred to the wake. Therefore, after some propagation distance, the group velocity of the leading edge of the pump pulse-and thus of the driven electron plasma wave-will slow down. This can have implications for the dephasing length of the accelerated electrons and therefore needs to be understood experimentally. We have carried out an experimental investigation where we have measured the velocity v f of the 'wave-front' of the plasma wave driven by a nominally 50 fs (full width half maximum), intense (a 0 ≅ 1), 0.815 μm laser pulse. To determine the speed of the wave front, time- and space-resolved refractometry, interferometry and Thomson scattering were used. Although a laser pulse propagating through a relatively low-density plasma (n e = 1.3 x 10 19 cm -3 ) showed no measurable changes in v f over 1.3 mm (and no accelerated electrons), a high-density plasma (n e = 5 x 10 19 cm -3 ) generated accelerated electrons and showed a continuous change in v f as the laser pulse propagated through the plasma. Possible causes and consequences of the observed v f evolution are discussed.

  8. Tailoring the laser pulse shape to improve the quality of the self-injected electron beam in laser wakefield acceleration

    International Nuclear Information System (INIS)

    Upadhyay, Ajay K.; Samant, Sushil A.; Krishnagopal, S.

    2013-01-01

    In laser wakefield acceleration, tailoring the shape of the laser pulse is one way of influencing the laser-plasma interaction and, therefore, of improving the quality of the self-injected electron beam in the bubble regime. Using three-dimensional particle-in-cell simulations, the evolution dynamics of the laser pulse and the quality of the self-injected beam, for a Gaussian pulse, a positive skew pulse (i.e., one with sharp rise and slow fall), and a negative skew pulse (i.e., one with a slow rise and sharp fall) are studied. It is observed that with a negative skew laser pulse there is a substantial improvement in the emittance (by around a factor of two), and a modest improvement in the energy-spread, compared to Gaussian as well as positive skew pulses. However, the injected charge is less in the negative skew pulse compared to the other two. It is also found that there is an optimal propagation distance that gives the best beam quality; beyond this distance, though the energy increases, the beam quality deteriorates, but this deterioration is least for the negative skew pulse. Thus, the negative skew pulse gives an improvement in terms of beam quality (emittance and energy spread) over what one can get with a Gaussian or positive skew pulse. In part, this is because of the lesser injected charge, and the strong suppression of continuous injection for the negative skew pulse.

  9. A tunable electron beam source using trapping of electrons in a density down-ramp in laser wakefield acceleration.

    Science.gov (United States)

    Ekerfelt, Henrik; Hansson, Martin; Gallardo González, Isabel; Davoine, Xavier; Lundh, Olle

    2017-09-25

    One challenge in the development of laser wakefield accelerators is to demonstrate sufficient control and reproducibility of the parameters of the generated bunches of accelerated electrons. Here we report on a numerical study, where we demonstrate that trapping using density down-ramps allows for tuning of several electron bunch parameters by varying the properties of the density down-ramp. We show that the electron bunch length is determined by the difference in density before and after the ramp. Furthermore, the transverse emittance of the bunch is controlled by the steepness of the ramp. Finally, the amount of trapped charge depends both on the density difference and on the steepness of the ramp. We emphasize that both parameters of the density ramp are feasible to vary experimentally. We therefore conclude that this tunable electron accelerator makes it suitable for a wide range of applications, from those requiring short pulse length and low emittance, such as the free-electron lasers, to those requiring high-charge, large-emittance bunches to maximize betatron X-ray generation.

  10. Note: Real-time monitoring via second-harmonic interferometry of a flow gas cell for laser wakefield acceleration

    Science.gov (United States)

    Brandi, F.; Giammanco, F.; Conti, F.; Sylla, F.; Lambert, G.; Gizzi, L. A.

    2016-08-01

    The use of a gas cell as a target for laser wakefield acceleration (LWFA) offers the possibility to obtain stable and manageable laser-plasma interaction process, a mandatory condition for practical applications of this emerging technique, especially in multi-stage accelerators. In order to obtain full control of the gas particle number density in the interaction region, thus allowing for a long term stable and manageable LWFA, real-time monitoring is necessary. In fact, the ideal gas law cannot be used to estimate the particle density inside the flow cell based on the preset backing pressure and the room temperature because the gas flow depends on several factors like tubing, regulators, and valves in the gas supply system, as well as vacuum chamber volume and vacuum pump speed/throughput. Here, second-harmonic interferometry is applied to measure the particle number density inside a flow gas cell designed for LWFA. The results demonstrate that real-time monitoring is achieved and that using low backing pressure gas (<1 bar) and different cell orifice diameters (<2 mm) it is possible to finely tune the number density up to the 1019 cm-3 range well suited for LWFA.

  11. Note: Real-time monitoring via second-harmonic interferometry of a flow gas cell for laser wakefield acceleration.

    Science.gov (United States)

    Brandi, F; Giammanco, F; Conti, F; Sylla, F; Lambert, G; Gizzi, L A

    2016-08-01

    The use of a gas cell as a target for laser wakefield acceleration (LWFA) offers the possibility to obtain stable and manageable laser-plasma interaction process, a mandatory condition for practical applications of this emerging technique, especially in multi-stage accelerators. In order to obtain full control of the gas particle number density in the interaction region, thus allowing for a long term stable and manageable LWFA, real-time monitoring is necessary. In fact, the ideal gas law cannot be used to estimate the particle density inside the flow cell based on the preset backing pressure and the room temperature because the gas flow depends on several factors like tubing, regulators, and valves in the gas supply system, as well as vacuum chamber volume and vacuum pump speed/throughput. Here, second-harmonic interferometry is applied to measure the particle number density inside a flow gas cell designed for LWFA. The results demonstrate that real-time monitoring is achieved and that using low backing pressure gas (<1 bar) and different cell orifice diameters (<2 mm) it is possible to finely tune the number density up to the 10(19) cm(-3) range well suited for LWFA.

  12. Note: Real-time monitoring via second-harmonic interferometry of a flow gas cell for laser wakefield acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Brandi, F., E-mail: fernando.brandi@ino.it [Intense Laser Irradiation Laboratory (ILIL), Istituto Nazionale di Ottica (INO-CNR), Via Moruzzi 1, 56124 Pisa (Italy); Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genova (Italy); Giammanco, F.; Conti, F. [Dipartimento di Fisica, Università degli Studi di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Plasma Diagnostics and Technologies Ltd., via Matteucci n.38/D, 56124 Pisa (Italy); Sylla, F. [SourceLAB SAS, 86 Rue de Paris, 91400 Orsay (France); Lambert, G. [LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France); Gizzi, L. A. [Intense Laser Irradiation Laboratory (ILIL), Istituto Nazionale di Ottica (INO-CNR), Via Moruzzi 1, 56124 Pisa (Italy)

    2016-08-15

    The use of a gas cell as a target for laser wakefield acceleration (LWFA) offers the possibility to obtain stable and manageable laser-plasma interaction process, a mandatory condition for practical applications of this emerging technique, especially in multi-stage accelerators. In order to obtain full control of the gas particle number density in the interaction region, thus allowing for a long term stable and manageable LWFA, real-time monitoring is necessary. In fact, the ideal gas law cannot be used to estimate the particle density inside the flow cell based on the preset backing pressure and the room temperature because the gas flow depends on several factors like tubing, regulators, and valves in the gas supply system, as well as vacuum chamber volume and vacuum pump speed/throughput. Here, second-harmonic interferometry is applied to measure the particle number density inside a flow gas cell designed for LWFA. The results demonstrate that real-time monitoring is achieved and that using low backing pressure gas (<1 bar) and different cell orifice diameters (<2 mm) it is possible to finely tune the number density up to the 10{sup 19} cm{sup −3} range well suited for LWFA.

  13. High-energy coherent terahertz radiation emitted by wide-angle electron beams from a laser-wakefield accelerator

    Science.gov (United States)

    Yang, Xue; Brunetti, Enrico; Jaroszynski, Dino A.

    2018-04-01

    High-charge electron beams produced by laser-wakefield accelerators are potentially novel, scalable sources of high-power terahertz radiation suitable for applications requiring high-intensity fields. When an intense laser pulse propagates in underdense plasma, it can generate femtosecond duration, self-injected picocoulomb electron bunches that accelerate on-axis to energies from 10s of MeV to several GeV, depending on laser intensity and plasma density. The process leading to the formation of the accelerating structure also generates non-injected, sub-picosecond duration, 1–2 MeV nanocoulomb electron beams emitted obliquely into a hollow cone around the laser propagation axis. These wide-angle beams are stable and depend weakly on laser and plasma parameters. Here we perform simulations to characterise the coherent transition radiation emitted by these beams if passed through a thin metal foil, or directly at the plasma–vacuum interface, showing that coherent terahertz radiation with 10s μJ to mJ-level energy can be produced with an optical to terahertz conversion efficiency up to 10‑4–10‑3.

  14. On the properties of synchrotron-like X-ray emission from laser wakefield accelerated electron beams

    Science.gov (United States)

    McGuffey, C.; Schumaker, W.; Matsuoka, T.; Chvykov, V.; Dollar, F.; Kalintchenko, G.; Kneip, S.; Najmudin, Z.; Mangles, S. P. D.; Vargas, M.; Yanovsky, V.; Maksimchuk, A.; Thomas, A. G. R.; Krushelnick, K.

    2018-04-01

    The electric and magnetic fields responsible for electron acceleration in a Laser Wakefield Accelerator (LWFA) also cause electrons to radiate x-ray photons. Such x-ray pulses have several desirable properties including short duration and being well collimated with tunable high energy. We measure the scaling of this x-ray source experimentally up to laser powers greater than 100 TW. An increase in laser power allows electron trapping at a lower density as well as with an increased trapped charge. These effects resulted in an x-ray fluence that was measured to increase non-linearly with laser power. The fluence of x-rays was also compared with that produced from K-α emission resulting from a solid target interaction for the same energy laser pulse. The flux was shown to be comparable, but the LWFA x-rays had a significantly smaller source size. This indicates that such a source may be useful as a backlighter for probing high energy density plasmas with ultrafast temporal resolution.

  15. Wilting and biological additive effect on in situ degradability and chemical composition of Arachis pintoi cv Belomonte silage

    OpenAIRE

    Rosana Aparecida Possenti; Evaldo Ferrari Júnior; Valdinei Tadeu Paulino; Ivani Pozar Otsuk; Patrícia Brás

    2010-01-01

    The purpose of this work was to evaluate the effect of wilting and biological additive amendment on chemical composition, fermentation and ruminal degradability of Arachis pintoi cv Belmonte silage. The following treatments were analysed: T1- Arachis pintoi cv Belmonte fresh forage; T2 - Arachis pintoi cv Belmonte fresh forage plus bacterial additive added to the forage prior to the ensilage; T3- Arachis pintoi cv Belmonte wilted by the sun for 4 hours; T4- Arachis pintoi cv Belmonte wilted b...

  16. Analisis Tingkat Kepuasan Kerja Karyawan pada CV Sumber Pangan di Denpasar

    OpenAIRE

    SUPRATMAN, I WAYAN NOVA; USTRIYANA, I NYOMAN GEDE; DEWI, IDA AYU LISTIA

    2016-01-01

    Analysis of Job Satisfaction at CV Food Sources in DenpasarHuman resources is a factor of production which is very important for a company,compared with other factors of production include natural resources, capital, andskills. The purpose of this study was to determine the level of employee satisfactionCV Food Source in Denpasar. The location determination is done deliberately. Thetotal number of the population sampled that stout 40 employees CV Source of Foodin Denpasar. The factors used in...

  17. Pengaruh Budaya Organisasi, Kepemimpinan, dan Motivasi Kerja terhadap Kepuasan Kerja Karyawan CV Surya Raya

    Directory of Open Access Journals (Sweden)

    Laksmi Sito Dwi Irvianti

    2012-05-01

    Full Text Available This research was conducted on CV Surya Raya which is engaged in car shipping. The aim of this study is to determine the influence of organization culture, leadership, and working motivation partially to employees’ satisfaction in CV Surya Raya. The data was collected by conducting interviews with the company and distributing questionnaires to 67 employees as respondents and then analyzed using linear regression analysis method. From the research results, leadership variable does not have a significant impact on employees' job satisfaction in CV Surya Raya. Whereas, the motivation variable has greater influence on job satisfaction of CV Surya Raya employees compared to the organization's culture.

  18. CIVAC CV-01 type pressure gage for middle vacuum pumps

    International Nuclear Information System (INIS)

    Olaru, Grigore; Aculai, Agustin

    1997-01-01

    The digital display pressure gage CIVAC CV-01 measures absolute pressures in vacuum range of 10 2 - 10 -3 mbar in any installation or equipment generating or using low pressures. It uses a transducer type PIRANI, model TR-02. It is a portable device, easy to exploit and handle. It is applied in research, chemistry, metallurgical industry, mechanical engineering. The system of coupling the transducer to the enclosure where the pressure is to be measured is of type ISO-PNEUROP with flange, collar and adjusting ring with a DN 25 ring gasket. The technical and functional features are: - Measuring error: ± 35% of real conventional value ; - Response time: 20 ms; - Number of measuring points: 1; - Output signal: 0 - 10 V d.c.; - Repeatability error: 5%; - Max weight: 1,600 Kg; Size: 91 x 117 x 187 mm. (authors)

  19. Cytotoxic diterpenoids from Jatropha curcas cv. nigroviensrugosus CY Yang Roots.

    Science.gov (United States)

    Liu, JieQing; Yang, YuanFeng; Xia, JianJun; Li, XuYang; Li, ZhongRong; Zhou, Lin; Qiu, MingHua

    2015-09-01

    An investigation of phytochemicals from the roots of Jatropha curcas cv. nigroviensrugosus resulted in the isolation of twenty diterpenoids, including lathyranlactone, an unusual diterpenoid lactone possessing a 5/13/3 tricyclic skeleton, jatrocurcasenones A-E and jatrophodiones B-E, as well as 10 known analogues. All isolates were evaluated for cytotoxicity against the HL-60, SMMC-772, A-549, MCF-7 and SW480 human tumor cell lines using the MTS viability assay. Four of the known analogues showed cytotoxic activity in these cell lines, with IC50 values ranging from 2.0 to 23.0 μM. Moreover, the assessment of their cytotoxic structure-activity relationships showed the epoxy ring between C-5 and C-6 and the hydroxyl group at C-2 were the key functionalities for cytotoxicity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Sign Language Translator Application Using OpenCV

    Science.gov (United States)

    Triyono, L.; Pratisto, E. H.; Bawono, S. A. T.; Purnomo, F. A.; Yudhanto, Y.; Raharjo, B.

    2018-03-01

    This research focuses on the development of sign language translator application using OpenCV Android based, this application is based on the difference in color. The author also utilizes Support Machine Learning to predict the label. Results of the research showed that the coordinates of the fingertip search methods can be used to recognize a hand gesture to the conditions contained open arms while to figure gesture with the hand clenched using search methods Hu Moments value. Fingertip methods more resilient in gesture recognition with a higher success rate is 95% on the distance variation is 35 cm and 55 cm and variations of light intensity of approximately 90 lux and 100 lux and light green background plain condition compared with the Hu Moments method with the same parameters and the percentage of success of 40%. While the background of outdoor environment applications still can not be used with a success rate of only 6 managed and the rest failed.

  1. Gamma irradiation studies on Gladiolus cv. White Friendship

    International Nuclear Information System (INIS)

    Banerji, B.K.; Datta, S.K.; Sharma, S.C.

    1994-01-01

    Dormant corms of Gladiolus cv. White Friendship were irradiated with 250, 500, 750, 1000 and 1250 Gy of gamma rays. Reduction in survival, plant height, number of leaves and floret, spike length, leaf and corm size and delayed flowering were recorded after irradiation. Morphological abnormalities in foliage and florets and chromosomal aberration during root tip mitosis increased with increase in exposure. Flowering was ceased cent per cent in highest dose of 1250 Gy. LD 50 on survival basis was found in 750 Gy exposure. MV 2 and MV 3 also followed the similar pattern of results as exhibited by MV 1 plants. Pink flower colour mutation was detected in few plants as sectorial chimeric form in MV 2 in treated population. In MV 3 one plant produced spike with lighter pink florets in 750 Gy treatment. This mutant has been isolated in pure form. (author). 10 refs., 2 figs., 2 tabs

  2. Induced somatic mutation in mango, mangifera indica L. cv. Langra

    International Nuclear Information System (INIS)

    Siddiqui, S.H.

    1985-01-01

    Dormant buds of mango (Mangifera indica L. cv. Langra) exposed to acute gamma-irradiation dosages of 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 kiloroentgens (kR), were grafted on to one-year-old seedling stock. Dosages of 2.0 and 3.0 kR were found satisfactory for the purpose, as measured by bud lethality and scion growth. A bud graft from 3.0 kR bore fruits of excellent quality. Compared with the control, the fruits were heavier, larger and had more creamish-yellow pulp. None of the other morphological changes expressed by the mutant fruits, observed over three fruiting seasons, were disadvantageous. The tree habit is being further investigated before the mutant can be considered for release as an improved cultivar. (author)

  3. Analisis Pengukuran Produktivitas Perusahaan Alsintan CV. Cherry Sarana Agro

    Directory of Open Access Journals (Sweden)

    Prima Fithri

    2016-04-01

    Full Text Available CV Cherry Sarana Agro is a manufacturing company, which produces agricultural machinery. In reality, company evaluatesits work and performance based on level of profits. In order to maintain the company's performance, it is necessary to measures the productivity of company to see how effective the performance of this company. So it can be determined what is needed in order to improve the performance of the company and also can increase profits. Measuring the productivity can be seen from the financial data that obtained from the company. Then based on data processing, show this company's productivity levels decreased during the period of measurement and it means company requires efforts to increase the efficient use of inputs. It is necessary for company to increase its productivity for the future. This improvement was made by taking into account the partial productivity as inputs that affect the profitability of the company on an ongoing basis.

  4. CV activities on the LHC complex during the long shutdown

    CERN Document Server

    Deleval, S; Body, Y; Obrecht, M; Moccia, S; Peon, G

    2011-01-01

    The presentation gives an overview of the major projects and work foreseen to be performed during next long shutdown on cooling and ventilation plants. Several projects are needed following the experience of the last years when LHC was running, in particular the modifications in the water cooling circuits presently in overflow. Some other projects are linked to the CV consolidation plan. Finally, most of the work shall be done to respond to additional requests: SR buildings air conditioning, the need to be able to clean and maintain the LHC cooling towers without a complete stop of cooling circuits, the upgrade of the air conditioning of the CCC rack room cooling etc. For all these activities, the author will detail constraints and the impact on the schedule and on the operation of the plants that will however need to run for most of the shutdown duration. The consequence of postponing the long shutdown from 2012 to 2013 will be also covered.

  5. Propolis extract in postharvest conservation Solo papaya cv. 'Golden'

    Directory of Open Access Journals (Sweden)

    Flávia Regina Passos

    2016-12-01

    Full Text Available The high perishability of papaya (Carica papaya L. reduces its lifespan as well as limits marketing. Coating the fruits is an alternative to aid food preservation. We aimed to evaluate the effects of coating propolis extract on the physicochemical characteristics of papaya stored at room temperature. Solo papayas cv. 'Golden' were randomly divided into five postharvest treatment groups, three forms of dip-coating (70% alcohol, hydroalcoholic extract of propolis to 2.5%, and hydroalcoholic extract of propolis to 5% and two controls (one uncoated and one with refrigerated uncoated fruits. The weight loss, firmness, soluble solids (SS, titratable acidity (TA, SS/TA, and hydrogen potential (pH were evaluated at the intervals of 4 days every 12th storage day. Sensory analysis was performed on the 4th day of storage of papayas and evaluated by untrained through the acceptance testing. Treatments “refrigerated”, “propolis 2.5%”, and “5% propolis” presented with the lowest weight loss. The firmness level for treatment propolis 5% was superior to that of control, alcohol, and 2.5% propolis treatments. The SS was greater for propolis 5% treatment, which only differed from the alcohol treatment. The TA and SS/TA did not vary with the treatments, but with the storage time. The pH of refrigerated papaya showed significant differences in relation to other treatments. The fruits subjected to refrigerated treatment presented with chilling injury. Papayas coated with propolis extract showed sensory acceptability similar to that in other treatments on the 4th day of storage. The coating of propolis extract is a promising alternative for the control of weight loss and for the maintenance of firmness in Solo papaya cv. 'Golden'.

  6. Core Problem: Does the CV Parent Body Magnetization require differentiation?

    Science.gov (United States)

    O'Brien, T.; Tarduno, J. A.; Smirnov, A. V.

    2016-12-01

    Evidence for the presence of past dynamos from magnetic studies of meteorites can provide key information on the nature and evolution of parent bodies. However, the suggestion of a past core dynamo for the CV parent body based on the study of the Allende meteorite has led to a paradox: a core dynamo requires differentiation, evidence for which is missing in the meteorite record. The key parameter used to distinguish core dynamo versus external field mechanisms is absolute field paleointensity, with high values (>>1 μT) favoring the former. Here we explore the fundamental requirements for absolute field intensity measurement in the Allende meteorite: single domain grains that are non-interacting. Magnetic hysteresis and directional data define strong magnetic interactions, negating a standard interpretation of paleointensity measurements in terms of absolute paleofield values. The Allende low field magnetic susceptibility is dominated by magnetite and FeNi grains, whereas the magnetic remanence is carried by an iron sulfide whose remanence-carrying capacity increases with laboratory cycling at constant field values, indicating reordering. The iron sulfide and FeNi grains are in close proximity, providing mineralogical context for interactions. We interpret the magnetization of Allende to record the intense early solar wind with metal-sulfide interactions amplifying the field, giving the false impression of a higher field value in some prior studies. An undifferentiated CV parent body is thus compatible with Allende's magnetization. Early solar wind magnetization should be the null hypothesis for evaluating the source of magnetization for chondrites and other meteorites.

  7. Death of pastures syndrome: tissue changes in Urochloa hybrida cv. Mulato II and Urochloa brizantha cv. Marandu

    Directory of Open Access Journals (Sweden)

    N. G. Ribeiro-Júnior

    Full Text Available Abstract The quality of forage production is a prerequisite to raising livestock. Therefore, income losses in this activity, primarily cattle raising, can result in the impossibility of economic activity. Through the qualitative and quantitative anatomical study of Urochloa hybrida cv. Mulato II and U. brizantha cv. Marandu, we searched for descriptions and compared changes in the individual vegetative body from populations with death syndrome pastures (DPS. Specimens were collected at different physiological stages from farms in northern Mato Grosso. After collection, the individuals were fixed in FAA50 and stored in 70% alcohol. Histological slides were prepared from the middle third of the sections of roots, rhizomes, and leaves, and the proportions and characteristics of tissues were evaluated in healthy, intermediate, and advanced stages of DPS. Changes were compared between cultivars. With the advancement of the syndrome, the following changes were observed: a more marked decrease in the length of roots in U. hybrida; disorganization of the cortical region of the roots and rhizome cultivars; fungal hyphae in roots and aerenchyma formation in U. hybrida; a decrease in sclerenchyma fiber proportions in roots and leaves; sclerification of the epidermis of U. brizantha rhizomes; and an increase in pericyclic fibers in U. hybrida. Furthermore, there was a decrease in the volume of epidermal cells of the abaxial face of the leaves of both cultivars, with a greater reduction in U. hybrida; a gradual decrease in thickness in the midrib of leaves similar to leaf mesophyll; conduction system obstructions; partial or total cell lysis in roots and rhizomes affected by the syndrome. Obstructions in sieve tube element and companion cells, and sometimes obstruction in xylem vessel elements. The evolution of DPS in cultivars was similar, but there were variations, arising probably from the physiological response to stress, such as aerenchyma formation in

  8. Phase space linearization and external injection of electron bunches into laser-driven plasma wakefields at REGAE

    International Nuclear Information System (INIS)

    Zeitler, Benno Michael Georg

    2017-01-01

    Laser Wake field Acceleration (LWFA) has the potential to become the next-generation acceleration technique for electrons. In particular, the large field gradients provided by these plasma-based accelerators are an appealing property, promising a significant reduction of size for future machines and user facilities. Despite the unique advantages of these sources, however, as of today, the produced electron bunches cannot yet compete in all beam quality criteria compared to conventional acceleration methods. Especially the stability in terms of beam pointing and energy gain, as well as a comparatively large energy spread of LWFA electron bunches require further advancement for their applicability. The accelerated particles are typically trapped from within the plasma which is used to create the large field gradients in the wake of a high-power laser. From this results a lack of control and access to observing the actual electron injection - and, consequently, a lack of experimental verification. To tackle this problem, the injection of external electrons into a plasma wakefield seems promising. In this case, the initial beam parameters are known, so that a back-calculation and reconstruction of the wakefield structure are feasible. Such an experiment is planned at the Relativistic Electron Gun for Atomic Exploration (REGAE). REGAE, which is located at DESY in Hamburg, is a small linear accelerator offering unique beam parameters compatible with the requirements of the planned experiment. The observations and results gained from such an external injection are expected to improve the beam quality and stability of internal injection variants, due to the broadened understanding of the underlying plasma dynamics. Furthermore, an external injection will always be required for so-called staging of multiple LWFA-driven cavities. Also, the demonstration of a suchlike merging of conventional and plasma accelerators gives rise to novel hybrid accelerators, where the matured

  9. Phase space linearization and external injection of electron bunches into laser-driven plasma wakefields at REGAE

    Energy Technology Data Exchange (ETDEWEB)

    Zeitler, Benno Michael Georg [Hamburg Univ. (Germany). Fakultaet fuer Mathematik, Informatik und Naturwissenschaften

    2017-01-15

    Laser Wake field Acceleration (LWFA) has the potential to become the next-generation acceleration technique for electrons. In particular, the large field gradients provided by these plasma-based accelerators are an appealing property, promising a significant reduction of size for future machines and user facilities. Despite the unique advantages of these sources, however, as of today, the produced electron bunches cannot yet compete in all beam quality criteria compared to conventional acceleration methods. Especially the stability in terms of beam pointing and energy gain, as well as a comparatively large energy spread of LWFA electron bunches require further advancement for their applicability. The accelerated particles are typically trapped from within the plasma which is used to create the large field gradients in the wake of a high-power laser. From this results a lack of control and access to observing the actual electron injection - and, consequently, a lack of experimental verification. To tackle this problem, the injection of external electrons into a plasma wakefield seems promising. In this case, the initial beam parameters are known, so that a back-calculation and reconstruction of the wakefield structure are feasible. Such an experiment is planned at the Relativistic Electron Gun for Atomic Exploration (REGAE). REGAE, which is located at DESY in Hamburg, is a small linear accelerator offering unique beam parameters compatible with the requirements of the planned experiment. The observations and results gained from such an external injection are expected to improve the beam quality and stability of internal injection variants, due to the broadened understanding of the underlying plasma dynamics. Furthermore, an external injection will always be required for so-called staging of multiple LWFA-driven cavities. Also, the demonstration of a suchlike merging of conventional and plasma accelerators gives rise to novel hybrid accelerators, where the matured

  10. High-quality electron beam generation and bright betatron radiation from a cascaded laser wakefield accelerator (Conference Presentation)

    Science.gov (United States)

    Liu, Jiansheng; Wang, Wentao; Li, Wentao; Qi, Rong; Zhang, Zhijun; Yu, Changhai; Wang, Cheng; Liu, Jiaqi; Qing, Zhiyong; Ming, Fang; Xu, Yi; Leng, Yuxin; Li, Ruxin; Xu, Zhizhan

    2017-05-01

    One of the major goals of developing laser wakefiled accelerators (LWFAs) is to produce compact high-energy electron beam (e-beam) sources, which are expected to be applied in developing compact x-ray free-electron lasers and monoenergetic gamma-ray sources. Although LWFAs have been demonstrated to generate multi-GeV e-beams, to date they are still failed to produce high quality e beams with several essential properties (narrow energy spread, small transverse emittance and high beam charge) achieved simultaneously. Here we report on the demonstration of a high-quality cascaded LWFA experimentally via manipulating electron injection, seeding in different periods of the wakefield, as well as controlling energy chirp for the compression of energy spread. The cascaded LWFA was powered by a 1-Hz 200-TW femtosecond laser facility at SIOM. High-brightness e beams with peak energies in the range of 200-600 MeV, 0.4-1.2% rms energy spread, 10-80 pC charge, and 0.2 mrad rms divergence are experimentally obtained. Unprecedentedly high 6-dimensional (6-D) brightness B6D,n in units of A/m2/0.1% was estimated at the level of 1015-16, which is very close to the typical brightness of e beams from state-of-the-art linac drivers and several-fold higher than those of previously reported LWFAs. Furthermore, we propose a scheme to minimize the energy spread of an e beam in a cascaded LWFA to the one-thousandth-level by inserting a stage to compress its longitudinal spatial distribution via velocity bunching. In this scheme, three-segment plasma stages are designed for electron injection, e-beam length compression, and e-beam acceleration, respectively. A one-dimensional theory and two-dimensional particle-in-cell simulations have demonstrated this scheme and an e beam with 0.2% rms energy spread and low transverse emittance could be generated without loss of charge. Based on the high-quality e beams generated in the LWFA, we have experimentally realized a new scheme to enhance the

  11. Pump depletion limited evolution of the relativistic plasma wave-front in a forced laser-wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Fang, F; Clayton, C E; Marsh, K A; Pak, A E; Ralph, J E; Joshi, C [Department of Electrical Engineering, University of California, Los Angeles, CA 90095 (United States); Lopes, N C [Grupo de Lasers e Plasmas, Instituto Superior Tecnico, Lisbon (Portugal)], E-mail: cclayton@ucla.edu

    2009-02-15

    In a forced laser-wakefield accelerator experiment (Malka et al 2002 Science 298 1596) where the length of the pump laser pulse is a few plasma periods long, the leading edge of the laser pulse undergoes frequency downshifting and head erosion as the laser energy is transferred to the wake. Therefore, after some propagation distance, the group velocity of the leading edge of the pump pulse-and thus of the driven electron plasma wave-will slow down. This can have implications for the dephasing length of the accelerated electrons and therefore needs to be understood experimentally. We have carried out an experimental investigation where we have measured the velocity v{sub f} of the 'wave-front' of the plasma wave driven by a nominally 50 fs (full width half maximum), intense (a{sub 0} {approx_equal} 1), 0.815 {mu}m laser pulse. To determine the speed of the wave front, time- and space-resolved refractometry, interferometry and Thomson scattering were used. Although a laser pulse propagating through a relatively low-density plasma (n{sub e} = 1.3 x 10{sup 19} cm{sup -3}) showed no measurable changes in v{sub f} over 1.3 mm (and no accelerated electrons), a high-density plasma (n{sub e} = 5 x 10{sup 19} cm{sup -3}) generated accelerated electrons and showed a continuous change in v{sub f} as the laser pulse propagated through the plasma. Possible causes and consequences of the observed v{sub f} evolution are discussed.

  12. Forward directed x-ray from source produced by relativistic electrons from a Self-Modulated Laser Wakefield Accelerator

    Science.gov (United States)

    Lemos, Nuno; Albert, Felicie; Shaw, Jessica; King, Paul; Milder, Avi; Marsh, Ken; Pak, Arthur; Joshi, Chan

    2017-10-01

    Plasma-based particle accelerators are now able to provide the scientific community with novel light sources. Their applications span many disciplines, including high-energy density sciences, where they can be used as probes to explore the physics of dense plasmas and warm dense matter. A recent advance is in the experimental and theoretical characterization of x-ray emission from electrons in the self-modulated laser wakefield regime (SMLWFA) where little is known about the x-ray properties. A series of experiments at the LLNL Jupiter Laser Facility, using the 1 ps 150 J Titan laser, have demonstrated low divergence electron beams with energies up to 300 MeV and 6 nCs of charge, and betatron x-rays with critical energies up to 20 keV. This work identifies two other mechanisms which produce high energy broadband x-rays and gamma-rays from the SMLWFA: Bremsstrahlung and inverse Compton scattering. We demonstrate the use of Compton scattering and bremsstrahlung to generate x/Gamma-rays from 3 keV up to 1.5 MeV with a source size of 50um and a divergence of 100 mrad. This work is an important step towards developing this x-ray light source on large-scale international laser facilities, and also opens up the prospect of using them for applications. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under the contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC.

  13. Generating multi-GeV electron bunches using single stage laser wakefield acceleration in a 3D nonlinear regime

    Directory of Open Access Journals (Sweden)

    W. Lu

    2007-06-01

    Full Text Available The extraordinary ability of space-charge waves in plasmas to accelerate charged particles at gradients that are orders of magnitude greater than in current accelerators has been well documented. We develop a phenomenological framework for laser wakefield acceleration (LWFA in the 3D nonlinear regime, in which the plasma electrons are expelled by the radiation pressure of a short pulse laser, leading to nearly complete blowout. Our theory provides a recipe for designing a LWFA for given laser and plasma parameters and estimates the number and the energy of the accelerated electrons whether self-injected or externally injected. These formulas apply for self-guided as well as externally guided pulses (e.g. by plasma channels. We demonstrate our results by presenting a sample particle-in-cell (PIC simulation of a 30   fs, 200 TW laser interacting with a 0.75 cm long plasma with density 1.5×10^{18}  cm^{-3} to produce an ultrashort (10 fs monoenergetic bunch of self-injected electrons at 1.5 GeV with 0.3 nC of charge. For future higher-energy accelerator applications, we propose a parameter space, which is distinct from that described by Gordienko and Pukhov [Phys. Plasmas 12, 043109 (2005PHPAEN1070-664X10.1063/1.1884126] in that it involves lower plasma densities and wider spot sizes while keeping the intensity relatively constant. We find that this helps increase the output electron beam energy while keeping the efficiency high.

  14. Strategies for mitigating the ionization-induced beam head erosion problem in an electron-beam-driven plasma wakefield accelerator

    Directory of Open Access Journals (Sweden)

    W. An

    2013-10-01

    Full Text Available Strategies for mitigating ionization-induced beam head erosion in an electron-beam-driven plasma wakefield accelerator (PWFA are explored when the plasma and the wake are both formed by the transverse electric field of the beam itself. Beam head erosion can occur in a preformed plasma because of a lack of focusing force from the wake at the rising edge (head of the beam due to the finite inertia of the electrons. When the plasma is produced by field ionization from the space charge field of the beam, the head erosion is significantly exacerbated due to the gradual recession (in the beam frame of the 100% ionization contour. Beam particles in front of the ionization front cannot be focused (guided causing them to expand as in vacuum. When they expand, the location of the ionization front recedes such that even more beam particles are completely unguided. Eventually this process terminates the wake formation prematurely, i.e., well before the beam is depleted of its energy. Ionization-induced head erosion can be mitigated by controlling the beam parameters (emittance, charge, and energy and/or the plasma conditions. In this paper we explore how the latter can be optimized so as to extend the beam propagation distance and thereby increase the energy gain. In particular we show that, by using a combination of the alkali atoms of the lowest practical ionization potential (Cs for plasma formation and a precursor laser pulse to generate a narrow plasma filament in front of the beam, the head erosion rate can be dramatically reduced. Simulation results show that in the upcoming “two-bunch PWFA experiments” on the FACET facility at SLAC national accelerator laboratory the energy gain of the trailing beam can be up to 10 times larger for the given parameters when employing these techniques. Comparison of the effect of beam head erosion in preformed and ionization produced plasmas is also presented.

  15. Laser wakefield generated X-ray probe for femtosecond time-resolved measurements of ionization states of warm dense aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Mo, M. Z.; Chen, Z.; Tsui, Y. Y.; Fedosejevs, R. [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada); Fourmaux, S.; Saraf, A.; Otani, K.; Kieffer, J. C. [INRS-EMT, Université du Québec, 1650 Lionel Boulet, Varennes, Québec J3X 1S2 (Canada); Ng, A. [Department of Physics and Astronomy, University of British Columbia, British Columbia V6T 1Z1 (Canada)

    2013-12-15

    We have developed a laser wakefield generated X-ray probe to directly measure the temporal evolution of the ionization states in warm dense aluminum by means of absorption spectroscopy. As a promising alternative to the free electron excited X-ray sources, Betatron X-ray radiation, with femtosecond pulse duration, provides a new technique to diagnose femtosecond to picosecond transitions in the atomic structure. The X-ray probe system consists of an adjustable Kirkpatrick-Baez (KB) microscope for focusing the Betatron emission to a small probe spot on the sample being measured, and a flat Potassium Acid Phthalate Bragg crystal spectrometer to measure the transmitted X-ray spectrum in the region of the aluminum K-edge absorption lines. An X-ray focal spot size of around 50 μm was achieved after reflection from the platinum-coated 10-cm-long KB microscope mirrors. Shot to shot positioning stability of the Betatron radiation was measured resulting in an rms shot to shot variation in spatial pointing on the sample of 16 μm. The entire probe setup had a spectral resolution of ∼1.5 eV, a detection bandwidth of ∼24 eV, and an overall photon throughput efficiency of the order of 10{sup −5}. Approximately 10 photons were detected by the X-ray CCD per laser shot within the spectrally resolved detection band. Thus, it is expected that hundreds of shots will be required per absorption spectrum to clearly observe the K-shell absorption features expected from the ionization states of the warm dense aluminum.

  16. How Adequate is your CV? Analyzing French CVs with ReaderBench

    NARCIS (Netherlands)

    Gutu, Gabriel; Dascalu, Mihai; Trausan-Matu, Stefan; Lepoivre, Olivier

    2017-01-01

    This study is aimed at presenting a new ReaderBench-based tool built to support candidates in increasing the quality of their CV for a job opening. Both the visual quality and the textual content are considered while also providing an overview and corresponding feedback for the entire CV.

  17. CV-Online tahab Londoni börsile / Annika Matson

    Index Scriptorium Estoniae

    Matson, Annika, 1976-

    2004-01-01

    Personaliotsinguga tegelev firma tahab tulevikus minna Londoni ja OMXi börsile. Diagramm: CV-Online Group loodab tänavu esmakordselt positiivse kulumieelse ärikasumi. Vt. samas: Üks CV-Online'i aktsionäridest on ka Google'i aktsionär; Väsinud ootamast esimest IPOt

  18. PERUMUSAN STRATEGI BERSAING JAHE INSTAN PRODUK CV. INTRAFOOD SURAKARTA MENGGUNAKAN PERCEPTUAL MAPPING

    Directory of Open Access Journals (Sweden)

    Mohd. Harisudin

    2013-11-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui posisi bersaing jahe instan produk CV. Intrafood dan strategi bersaing yang dapat direkomendasikan untuk meraih keberasilannya. Metode dasar yang digunakan adalah analisis deskriptif. Penentuan lokasi penelitian ditentukan dengan metode purposive, yaitu CV. Intrafood Surakarta. Jenis data yang digunakan dalam penelitian ini adalah data primer dan data sekunder. Metode analisis data menggunakan analisis Perceptual Mapping. Dari hasil penelitian diperoleh informasi bahwa jahe instan produk CV Intrafood berada pada peringkat ke-2 dari produk empat jahe instan yang diperbandingkan. Atribut yang dapat dijadikan kekuatan utama dalam meningkatkan pemasaran jahe instan produk CV. Intrafood adalah manfaat produk. Sisi yang paling lemah adalah atribut desain kemasan dan kinerja produk dalam kemasan. Abstract This study aims to determine the competitive position of the product instant ginger CV. Intrafood and competitive strategy can be recommended to achieve success. The basic method used is descriptive analysis. Determining the location of the study are determined by purposive method, namely CV. Intrafood Surakarta. Data used in this study is primary data and secondary data. Method analyzed using Perceptual Mapping. From the results of the study concluded that instant ginger of CV Intrafood product ranks second of four instant ginger products are compared. Attributes that can be used as a major force in improving product marketing instant ginger CV. Intrafood is the benefits of the product. The weakest side is the packaging design and performance attributes of the product in the packaging.

  19. ANALISIS KELAYAKAN INVESTASI PENAMBAHAN MESIN FRAIS BARU PADA CV. XYZ

    Directory of Open Access Journals (Sweden)

    Febri Muhammad Rachadian

    2013-04-01

    Full Text Available Perkembangan teknologi sangat pesat sehingga dunia perindustrian harus mengikuti perkembangannya. Penerapan teknologi diharapkan dapat meningkatkan proses produksi sehingga dapat menghasilkan produk yang berkualitas. Pada industri pembuatan mesin cetak di CV XYZ, mesin-mesin yang digunakan telah hampir lebih dari 20 tahun. Ada indikasi bahwa mesin-mesin tersebut sudah lewat umur pakainya. Alternatif yang digunakan selama ini ialah penggantian komponen yang rusak. Peneliti ingin membandingkan alternative tersebut dengan  penambahan mesin frais baru. Untuk itu diperlukan analisis kelayakan investasi penambahan mesin baru. Dalam perkiraan kurun waktu 10 tahun dan suku bunganya 15 % dengan menggunakan NPV, penambahan mesin frais menarik sebesar Rp 461.201.000 dibandingkan penggantian komponen yang rusak sebesar Rp 211.227.000. Sebaliknya pada PBP, penggantian komponen yang rusak masih mengungguli dengan 1 tahun 4 bulan dibandingkan penambahan mesin frais baru selama 2 tahun 1 bulan. Begitupun juga PI penggantian komponen yang rusak masih menarik sebesar 4,2 dibandingkan PI penambahan mesin frais baru sebesar 2,56. Dapat disimpulkan bahwa dalam jangka waktu 10 tahun, alternatif penggantian komponen yang rusak masih lebih baik dibandingkan penambahan mesin frais baru. Namun, untuk investasi jangka panjang, mungkin saja alternatif penambahan mesin frais baru lebih menarik. Kata Kunci: penggantian komponen rusak, mesin frais baru, mesin cetak Abstract The rapid development of technology makes the world of industry must follow its development. Application of technology is expected to improve the production process so it can be produce a quality product. On the industrial manufacture of printing machines in CV XYZ, the machines have been used almost more than 20 years. There are indications that those machines passed the age lifetime. The alternatives that have been used during this time are the replacement of defective parts. Researchers wanted to

  20. Nitrogen fertilization on the establishment of Arachis pintoi cv. Belmonte

    Directory of Open Access Journals (Sweden)

    Rita Manuele Porto Sales

    2012-11-01

    Full Text Available The objective was to evaluate the effect of nitrogen fertilization on the establishment of forage peanut (Arachis pintoi cv. Belmonte propagated vegetatively. The experiment was conducted in a greenhouse in a completely randomized design with treatments arranged in a 2 × 4 factorial design - two ages (70 and 85 days after planting and four nitrogen doses (0, 40, 80 and 120 kg/ha - with four replications. Morphogenetic and structural characteristics and production were evaluated. The nitrogen accelerated the establishment of the forage peanut with an increase in dry weight of green leaves and stolons. The greatest length of stolons (48.0 cm was obtained with a dose equivalent to 86 kg N/ha and higher density of stolons (20 stolons/vase between 78 and 82 kg N/ha. Nitrogen fertilization also reduced the phyllochron from 6.7 to 4.6 days/leaf. These data were more intense at 85 days, suggesting greater photosynthetic contribution during this period related to the large number of leaves after 70 days. Therefore, nitrogen can be an important tool to accelerate the establishment of pure stands of forage peanut.

  1. EVALUASI SISTEM INFORMASI PERSEDIAAN PADA CV. SARANA TELEMAXINDO

    Directory of Open Access Journals (Sweden)

    Nelly Nelly

    2010-10-01

    Full Text Available Evaluation objectives of inventory information systems at CV. Facilities Telemaxindo was to evaluate the weaknesses of the implementation of internal control, as well as estimating and assessing possible risks that might arise. The research method used is literature study of reference books in the library, and field study consisted of observation, interviews with relevant parties, creating check lists, check the inventory information systems documentation, and testing of inventory application systems. The results are findings of control weaknesses in the implementation of security management, operational management control, boundary control, input control, and output control on the present inventory information system. These weaknesses could pose a risk and if not dealt soon it could hurt the company. The resulting conclusion of the security management control, boundary control, control input, and output control is not running well so that it needs to be improved in accordance with the recommendations, while operational management control has been running fairly well.Keywords: evaluation, information system, inventory

  2. Infrared small target detection technology based on OpenCV

    Science.gov (United States)

    Liu, Lei; Huang, Zhijian

    2013-09-01

    Accurate and fast detection of infrared (IR) dim target has very important meaning for infrared precise guidance, early warning, video surveillance, etc. In this paper, some basic principles and the implementing flow charts of a series of algorithms for target detection are described. These algorithms are traditional two-frame difference method, improved three-frame difference method, background estimate and frame difference fusion method, and building background with neighborhood mean method. On the foundation of above works, an infrared target detection software platform which is developed by OpenCV and MFC is introduced. Three kinds of tracking algorithms are integrated in this software. In order to explain the software clearly, the framework and the function are described in this paper. At last, the experiments are performed for some real-life IR images. The whole algorithm implementing processes and results are analyzed, and those algorithms for detection targets are evaluated from the two aspects of subjective and objective. The results prove that the proposed method has satisfying detection effectiveness and robustness. Meanwhile, it has high detection efficiency and can be used for real-time detection.

  3. Seven health physics calculator programs for the HP-41CV

    International Nuclear Information System (INIS)

    Rittmann, P.D.

    1984-08-01

    Several user-oriented programs for the Hewlett-Packard HP-41CV are explained. The first program builds, stores, alters, and ages a list of radionuclides. This program only handles single- and double-decay chains. The second program performs convenient conversions for the six nuclides of concern in plutonium handling. The conversions are between mass, activity, and weight percents of the isotopes. The source can be aged and/or neutron generation rates can be computed. The third program is a timekeeping program that improves the process of manually estimating and tracking personnel exposure during high dose rate tasks by replacing the pencil, paper, and stopwatch method. This program requires a time module. The remaining four programs deal with computations of time-integrated air concentrations at various distances from an airborne release. Building wake effects, source depletion by ground deposition, and sector averaging can all be included in the final printout of the X/Q - Hanford and X/Q - Pasquill programs. The shorter versions of these, H/Q and P/Q, compute centerline or sector-averaged values and include a subroutine to facilitate dose estimation by entering dose factors and quantities released. The horizontal and vertical dispersion parameters in the Pasquill-Gifford programs were modeled with simple, two-parameter functions that agreed very well with the usual textbook graphs. 8 references, 7 appendices

  4. A virtual computing infrastructure for TS-CV SCADA systems

    CERN Document Server

    Poulsen, S

    2008-01-01

    In modern data centres, it is an emerging trend to operate and manage computers as software components or logical resources and not as physical machines. This technique is known as â€ワvirtualisation” and the new computers are referred to as â€ワvirtual machines” (VMs). Multiple VMs can be consolidated on a single hardware platform and managed in ways that are not possible with physical machines. However, this is not yet widely practiced for control system deployment. In TS-CV, a collection of VMs or a â€ワvirtual infrastructure” is installed since 2005 for SCADA systems, PLC program development, and alarm transmission. This makes it possible to consolidate distributed, heterogeneous operating systems and applications on a limited number of standardised high-performance servers in the Central Control Room (CCR). More generally, virtualisation assists in offering continuous computing services for controls and maintaining performance and assuring quality. Implementing our systems in a vi...

  5. MICROPROPAGAÇÃO DO KIWI CV. HAYWARD

    Directory of Open Access Journals (Sweden)

    SCALIZE FÁBIO EDUARDO

    2001-01-01

    Full Text Available O presente trabalho teve como objetivo desenvolver um protocolo para a obtenção de mudas de kiwi (Actinidia chinensis Planch, cv. Hayward, por meio do cultivo in vitro de cotilédones. Utilizou-se o meio de MURASHIGE & SKOOG (1962 -- MS, suplementado com dois tipos de auxina (AIA e AIB e uma citocinina (BAP. Foram verificados os efeitos de três doses de auxinas (0,125; 0,250 e 0,375 mg.L-1, combinadas com três doses de citocinina (0,5; 1,0 e 1,5 mg.L-1 na capacidade morfogênica dos explantes. Procedeu-se o estudo histológico dos órgãos das plântulas obtidas in vitro, e verificou-se, também, a capacidade de aclimatação das mudas ex vitro. A menor dose de AIB (0,125 mg.L-1, independentemente das doses de BAP, foi a mais eficaz na morfogênese dos explantes. Não foram verificadas alterações histológicas e anatômicas das plântulas obtidas in vitro. Aos três meses após o cultivo ex vitro dos explantes, verificou-se a sobrevivência de 88% das plantas transplantadas em condições de campo.

  6. Antidiabetic and anticancer activities of Mangifera indica cv. Okrong leaves

    Science.gov (United States)

    Ganogpichayagrai, Aunyachulee; Palanuvej, Chanida; Ruangrungsi, Nijsiri

    2017-01-01

    Diabetes and cancer are a major global public health problem. Plant-derived agents with undesirable side-effects were required. This study aimed to evaluate antidiabetic and anticancer activities of the ethanolic leaf extract of Mangifera indica cv. Okrong and its active phytochemical compound, mangiferin. Antidiabetic activities against yeast α-glucosidase and rat intestinal α-glucosidase were determined using 1 mM of p-nitro phenyl-α-D-glucopyranoside as substrate. Inhibitory activity against porcine pancreatic α-amylase was performed using 1 mM of 2-chloro-4 nitrophenol-α-D-maltotroside-3 as substrate. Nitrophenol product was spectrophotometrically measured at 405 nm. Anticancer activity was evaluated against five human cancer cell lines compared to two human normal cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Mango leaf extract and mangiferin exhibited dose-dependent inhibition against yeast α-glucosidase with the IC50 of 0.0503 and 0.5813 mg/ml, respectively, against rat α-glucosidase with the IC50 of 1.4528 and 0.4333 mg/ml, respectively, compared to acarbose with the IC50 of 11.9285 and 0.4493 mg/ml, respectively. For anticancer activity, mango leaf extract, at ≥200 μg/ml showed cytotoxic potential against all tested cancer cell lines. In conclusion, mango leaf possessed antidiabetic and anticancer potential in vitro. PMID:28217550

  7. Assembly of the Lactuca sativa, L. cv. Tizian draft genome sequence reveals differences within major resistance complex 1 as compared to the cv. Salinas reference genome.

    Science.gov (United States)

    Verwaaijen, Bart; Wibberg, Daniel; Nelkner, Johanna; Gordin, Miriam; Rupp, Oliver; Winkler, Anika; Bremges, Andreas; Blom, Jochen; Grosch, Rita; Pühler, Alfred; Schlüter, Andreas

    2018-02-10

    Lettuce (Lactuca sativa, L.) is an important annual plant of the family Asteraceae (Compositae). The commercial lettuce cultivar Tizian has been used in various scientific studies investigating the interaction of the plant with phytopathogens or biological control agents. Here, we present the de novo draft genome sequencing and gene prediction for this specific cultivar derived from transcriptome sequence data. The assembled scaffolds amount to a size of 2.22 Gb. Based on RNAseq data, 31,112 transcript isoforms were identified. Functional predictions for these transcripts were determined within the GenDBE annotation platform. Comparison with the cv. Salinas reference genome revealed a high degree of sequence similarity on genome and transcriptome levels, with an average amino acid identity of 99%. Furthermore, it was observed that two large regions are either missing or are highly divergent within the cv. Tizian genome compared to cv. Salinas. One of these regions covers the major resistance complex 1 region of cv. Salinas. The cv. Tizian draft genome sequence provides a valuable resource for future functional and transcriptome analyses focused on this lettuce cultivar. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. ANALISIS PENGUKURAN PRODUKTIVITAS PADA CV. CITRA JEPARA FURNITURE

    Directory of Open Access Journals (Sweden)

    Darminto Pujotomo

    2012-02-01

    Full Text Available CV. Citra Jepara adalah perusahaan furnitur ekspor. Pada masa itu, perusahaan hanya melihat level keuntungan untuk mengkaji perusahaan telah berjalan lebih baik atau kebalikannya. Hasil persepsi membuat perusahaan hanya sedikit memperhatikan efisiensi pemakaian sumber daya yang dimiliki (input sehingga perusahaan membutuhkan biaya besar untuk melakukan aktivitas perusahaan.Penelitian ini mempelajari evaluasi produktivitas perusahaan dan pengukuran serta hubungan antara level produktivitas dengan level profitabilitas (kemampuan perusahaan untuk menciptakan laba yang dapat dicapai oleh perusahaan.Hasil penelitian ini tentang pengukuran produktivitas parsial memperlihatkan level produktivitas berubah-ubah dan masih memerlukan usaha peningkatan produktivitas parsial terutama dalam pemakaian masing-masing input dengan efisien. Level Total Factor Productivity selama perioda pengukuran memperlihatkan level pertumbuhan positif. Ini melukiskan perusahaan sukses dalam mengelola input tenaga kerja dan modal kolektif yang dimiliki. Level Total Productivity selama perioda pengukuran menunjukkan level pertumbuhan yang berubah-ubah. Ini melukiskan perusahaan itu belum dapat mengelola input yang dimiliki keseluruhan dengan sukses. Untuk melukiskan hubungan antara produktivitas total dengan profitabilitas dari hasil penelitian bisa diketahui faktor produktivitas (0,998 mempunyai pengaruh lebih besar dibandingkan pemulihan harga (0,457 untuk peningkatan profitabilitas perusahaan selama kurun waktu satu tahun perioda pengukuran. Diperlukan usaha untuk meningkatkan profitabilitas perusahaan untuk periode mendatang disertai usaha untuk meningkatkan produktivitas yang memusatkan pada peningkatan produktivitas material dan produktivitas modal sebagai input yang sangat mempengaruhi profitabilitas perusahaan dengan cara berkelanjutkan dan berkesinambungan. Kata kunci: pengukuran evaluasi dan produktivitas, profitabilitas    CV. Citra Jepara is an export furniture

  9. Novel circulatory connection from the acupoint Zhong Wan(CV12 to pancreas

    Directory of Open Access Journals (Sweden)

    Minsoo Kim

    2008-03-01

    Full Text Available Objectives : Demonstrating a novel circulatory path from the acupoint(CV12 to the pancreas. Method : Alcian blue(1% solution, 20μl, pH 7.4 was injected into the acupoint(CV12. Two hours later the surfaces of internal organs were observed by using a stereomicroscope. Results : Alcian blue arrived and colored the omental fat band(OFB on the pancreas. The OFB connected the head and tail of the pancreas, the pancreas and the spleen, and the pancreas and the stomach. Conclusion : The existence of a novel circulatory path from the acupoint CV12 to the pancreas and its OFB was demonstrated.

  10. Analisis Strategi Mitigasi Resiko Pada Supply Chain CV Surya Cip Dengan House of Risk Model

    OpenAIRE

    Pertiwi, Yoana Ellen; Susanty, Aries

    2017-01-01

    Analysis of Risk Mitigation Strategies on CV Surya CIP's Supply Chain Using House of Risk Model. In the supply chain activities always has the potential of risk, therefore risk management is necessary for handling the risks. At the company that produces plastic molding machine such as CV Surya CIP, in its supply chain activities have a chance to arise risks. The purpose of this study is to identify the various risks that occur in the CV Surya CIP and its causes, severity and determine the ...

  11. Analisis Pengawasan Logistik Produk Aqua Ukuran 330ml Pada CV. Dlu'x Resto Samarinda

    OpenAIRE

    Mardiana, Ali Masuhud, H. Mulyadi Syp

    2016-01-01

    The problem in this research is "Are Determination Against Aqua Products Logistics Control 330ml sizes on CV. DLux Resto has been optimized? "This study aims to determine the amount of inventory on the CV aqua 330ml sizes. Dlu'x Resto in Samarinda.Formulation of the problem in this study is whether the determination of the logistical monitoring product inventory aqua 330ml sizes that have been carried out on the CV. Dlu'x Resto Samarinda already performed optimally.The hypothesis in this stud...

  12. Fox grape cv. Bordô (Vitis labrusca L.) and grapevine cv. Chardonnay (Vitis vinifera L.) cultivated in vitro under different carbohydrates, amino acids and 6-Benzylaminopurine levels

    OpenAIRE

    Carvalho, Dayse Cristina de; Silva, André Luís Lopes da; Schuck, Mariane Ruzza; Purcino, Marivel; Tanno, Guilherme Nakao; Biasi, Luiz Antonio

    2013-01-01

    The aim of this work was to study the influence of sucrose and glucose, amino acids and BAP (6-Benzylaminopurine) levels on in vitro shoot regeneration of fox grape cv. Bordô and grapevine cv. Chardonnay. The nodal segments from micropropagated material were used as explants and half-strength MS medium as the basal medium. Sucrose and glucose at 15, 30 and 45 g.L-1 were tested as a carbon source and the supplementation of adenine, asparagine, alanine, glycine, cysteine, glutamine, arginine wa...

  13. Limited geographic distribution of the novel cyclovirus CyCV-VN.

    Science.gov (United States)

    Le, Van Tan; de Jong, Menno D; Nguyen, Van Kinh; Nguyen, Vu Trung; Taylor, Walter; Wertheim, Heiman F L; van der Ende, Arie; van der Hoek, Lia; Canuti, Marta; Crusat, Martin; Sona, Soeng; Nguyen, Hanh Uyen; Giri, Abhishek; Nguyen, Thi Thuy Chinh Bkrong; Ho, Dang Trung Nghia; Farrar, Jeremy; Bryant, Juliet E; Tran, Tinh Hien; Nguyen, Van Vinh Chau; van Doorn, H Rogier

    2014-02-05

    A novel cyclovirus, CyCV-VN, was recently identified in cerebrospinal fluid (CSF) from patients with central nervous system (CNS) infections in central and southern Vietnam. To explore the geographic distribution of this novel virus, more than 600 CSF specimens from patients with suspected CNS infections in northern Vietnam, Cambodia, Nepal and The Netherlands were screened for the presence of CyCV-VN but all were negative. Sequence comparison and phylogenetic analysis between CyCV-VN and another novel cyclovirus recently identified in CSF from Malawian patients indicated that these represent distinct cycloviral species, albeit phylogenetically closely related. The data suggest that CyCV-VN has a limited geographic distribution within southern and central Vietnam. Further research is needed to determine the global distribution and diversity of cycloviruses and importantly their possible association with human disease.

  14. Analisis Pengaruh Lingkungan Kerja dan Pemberian Kompensasi terhadap Kinerja Karyawan CV Mum Indonesia

    Directory of Open Access Journals (Sweden)

    Jerry M. Logahan

    2012-05-01

    Full Text Available Mum CV is a company engaged in the sale of bread. To increase sales of bread (performance it needs to investigate the influence of work environment and compensation of employees. The method of analysis used in this study is descriptive, Pearson Regression, and Multiple Regression. The data were obtained from the employees performance by completing the questionnaires provided using Likert scale which was useful to determine the level of disagreement questions on the questionnaires. Results achieved in this study are the work environment has no significant influence on employees performance in CV Mum Indonesia, amounting to 0,068. Compensation has significant, no influence on employees performance in CV Mum Indonesia that is equal to 0,580 and there is a significant effect of 33.6%. Work environment and compensation have a significant impact on employees performance in CV Mum Indonesia. It is equal to 0,580 and there is a significant effect of 33.6%.

  15. Biofuels from the Fresh Water Microalgae Chlorella vulgaris (FWM-CV for Diesel Engines

    Directory of Open Access Journals (Sweden)

    Saddam H. Al-lwayzy

    2014-03-01

    Full Text Available This work aims to investigate biofuels for diesel engines produced on a lab-scale from the fresh water microalgae Chlorella vulgaris (FWM-CV. The impact of growing conditions on the properties of biodiesel produced from FWM-CV was evaluated. The properties of FWM-CV biodiesel were found to be within the ASTM standards for biodiesel. Due to the limited amount of biodiesel produced on the lab-scale, the biomass of dry cells of FWM-CV was used to yield emulsified water fuel. The preparation of emulsion fuel with and without FWM-CV cells was conducted using ultrasound to overcome the problems of large size microalgae colonies and to form homogenized emulsions. The emulsified water fuels, prepared using ultrasound, were found to be stable and the size of FWM-CV colonies were effectively reduced to pass through the engine nozzle safely. Engine tests at 3670 rpm were conducted using three fuels: cottonseed biodiesel CS-B100, emulsified cottonseed biodiesel water fuel, water and emulsifier (CS-E20 and emulsified water containing FWM-CV cells CS-ME20. The results showed that the brake specific fuel consumption (BSFC was increased by about 41% when the engine was fueled with emulsified water fuels compared to CS-B100. The engine power, exhaust gas temperature, NOx and CO2 were significantly lower than that produced by CS-B100. The CS-ME20 produced higher power than CS-E20 due to the heating value improvement as a result of adding FWM-CV cells to the fuel.

  16. Analisis Pengaruh Kemampuan, Usaha dan Dukungan Perusahaan terhadap Kinerja Karyawan pada CV Sandang Gloria Konveksindo

    OpenAIRE

    Logahan, Jerry; Sari, Synthia Atas; Marisa, Dian

    2012-01-01

    Clothing Konveksindo CV Gloria is a trading company engaged in the sale of products and clothing items. Therefore, the performance of employees is very important in achieving that goal. The purpose of this study was to analyze the influence of ability, effort, and support the company towards the employee's performance CV Gloria Konveksindo Clothing. The method of analysis used in this study is descriptive, Pearson Regression, and Multiple Regression. Data obtained from the appraisal of employ...

  17. Cyclovirus CyCV-VN species distribution is not limited to Vietnam and extends to Africa.

    Science.gov (United States)

    Garigliany, Mutien-Marie; Hagen, Ralf Matthias; Frickmann, Hagen; May, Jürgen; Schwarz, Norbert Georg; Perse, Amanda; Jöst, Hanna; Börstler, Jessica; Shahhosseini, Nariman; Desmecht, Daniel; Mbunkah, Herbert Afegenwi; Daniel, Achukwi Mbunkah; Kingsley, Manchang Tanyi; Campos, Renata de Mendonca; de Paula, Vanessa Salete; Randriamampionona, Njary; Poppert, Sven; Tannich, Egbert; Rakotozandrindrainy, Raphael; Cadar, Daniel; Schmidt-Chanasit, Jonas

    2014-12-18

    Cycloviruses, small ssDNA viruses of the Circoviridae family, have been identified in the cerebrospinal fluid from symptomatic human patients. One of these species, cyclovirus-Vietnam (CyCV-VN), was shown to be restricted to central and southern Vietnam. Here we report the detection of CyCV-VN species in stool samples from pigs and humans from Africa, far beyond their supposed limited geographic distribution.

  18. Characterization of a novel gene encoding ankyrin repeat domain from Cotesia vestalis polydnavirus (CvBV)

    International Nuclear Information System (INIS)

    Shi Min; Chen Yafeng; Huang Fang; Liu Pengcheng; Zhou Xueping; Chen Xuexin

    2008-01-01

    Cotesia vestalis (Haliday) is an endoparasitoid of Plutella xylostella (L.) larvae and injects a polydnavirus (CvBV) into its host during oviposition. In this report we describe the characterization of a gene (CvBV805) and its products. CvBV805 is located on the segment S8 of CvBV genome; it has a size of 909 bp and encodes a predicted protein of 125 amino acids. This protein contains an ankyrin repeat domain with a high degree of similarity with IκB-like genes. Gene transcripts were detected in extracts of the host as early as 2 h post-parasitization (p.p.) and continued to be detected through 24 h. Tissue-specific expression patterns showed that CvBV805 might be involved in early host immunosuppression. CvBV805 was detected in parasitized hosts at 12 h p.p. and in rBac-eGFP-CvBV805-infected Tn-5B1-4 cells at 72 h.p.i. by using western blots analysis. The size of the protein expressed in the host hemocytes and infected Tn-5B1-4 cells was 17 kDa and 56 kDa (including eGFP), respectively, which nearly corresponded with the predicted molecular weight (14.31 kDa) of CvBV805, suggesting that the protein did not undergo extensive post-translational modification. The protein was confirmed to be present within the nuclear region in hemocytes of the parasitized P. xylostella larvae at 48 h p.p. using confocal laser scanning microscopy

  19. Evaluation of faba beans ( Vicia faba cv. Fiord) and sweet lupins ...

    African Journals Online (AJOL)

    Evaluation of faba beans ( Vicia faba cv. Fiord) and sweet lupins ( Lupizus albus cv. Kiev) as protein sources for ... P igsi n the metabolisrna ndN balance trial consurned5 % less( P < 0.01)o 1'thel upind ietc omparedto the fabab eand iet (l 370 vs. | 440 gld).N o significandt ift'erenceisn the digestiblee nergy( DE) contenta nd ...

  20. Pengaruh Kualitas Pelayanan terhadap Loyalitas Pelanggan di Rental Mobil CV. Ilham Motor Gandu Mlarak Ponorogo

    OpenAIRE

    Dhika Amalia

    2015-01-01

    The purpose of this study was to determine the amount of quality customer service and loyalty to know a very dominant factor affecting customer loyalty in the CV . Ilham Motor. This research method is the primary data from the questionnaires , sampling technique is a technique associated with customer 100 CV Ilham Motor . Data analysis is a quantitative method to test the validity , reliability testing , multiple linear regression analysis , the correlation coefficient analytic , analytic det...

  1. [Habitat factor analysis for Torreya grandis cv. Merrillii based on spatial information technology].

    Science.gov (United States)

    Wang, Xiao-ming; Wang, Ke; Ao, Wei-jiu; Deng, Jin-song; Han, Ning; Zhu, Xiao-yun

    2008-11-01

    Torreya grandis cv. Merrillii, a tertiary survival plant, is a rare tree species of significant economic value and expands rapidly in China. Its special habitat factor analysis has the potential value to provide guide information for its planting, management, and sustainable development, because the suitable growth conditions for this tree species are special and strict. In this paper, the special habitat factors for T. grandis cv. Merrillii in its core region, i.e., in seven villages of Zhuji City, Zhejiang Province were analyzed with Principal Component Analysis (PCA) and a series of data, such as IKONOS image, Digital Elevation Model (DEM), and field survey data supported by the spatial information technology. The results showed that T. grandis cv. Merrillii exhibited high selectivity of environmental factors such as elevation, slope, and aspect. 96.22% of T. grandis cv. Merrillii trees were located at the elevation from 300 to 600 m, 97.52% of them were found to present on the areas whose slope was less than 300, and 74.43% of them distributed on sunny and half-sunny slopes. The results of PCA analysis indicated that the main environmental factors affecting the habitat of T. grandis cv. Merrillii were moisture, heat, and soil nutrients, and moisture might be one of the most important ecological factors for T. grandis cv. Merrillii due to the unique biological and ecological characteristics of the tree species.

  2. Design of a high charge (10 - 100 nC) and short pulse (2 - 5 ps) rf photocathode gun for wakefield acceleration

    International Nuclear Information System (INIS)

    Gai, W.

    1998-01-01

    In this paper we present a design report on a 1-1/2 cell, L Band RF photocathode gun that is capable of generating and accelerating electron beams with peak currents >10 kA. We have performed simulation for bunch intensities in the range of 10-100 nC with peak axial electrical field at the photocathode of 30-100 MV/m. Unlike conventional short electron pulse generation, this design does not require magnetic pulse compression. Based on numerical simulations using SUPERFISH and PARMELA, this design will produce 20-100 nC beam at 18 MeV with rms bunch length 0.6-1.25 mm and normalized transverse emittance 30-108 mm mrad. Applications of this beam for wakefield acceleration is also discussed

  3. Experimental Evidence of Radiation Reaction in the Collision of a High-Intensity Laser Pulse with a Laser-Wakefield Accelerated Electron Beam

    Science.gov (United States)

    Cole, J. M.; Behm, K. T.; Gerstmayr, E.; Blackburn, T. G.; Wood, J. C.; Baird, C. D.; Duff, M. J.; Harvey, C.; Ilderton, A.; Joglekar, A. S.; Krushelnick, K.; Kuschel, S.; Marklund, M.; McKenna, P.; Murphy, C. D.; Poder, K.; Ridgers, C. P.; Samarin, G. M.; Sarri, G.; Symes, D. R.; Thomas, A. G. R.; Warwick, J.; Zepf, M.; Najmudin, Z.; Mangles, S. P. D.

    2018-02-01

    The dynamics of energetic particles in strong electromagnetic fields can be heavily influenced by the energy loss arising from the emission of radiation during acceleration, known as radiation reaction. When interacting with a high-energy electron beam, today's lasers are sufficiently intense to explore the transition between the classical and quantum radiation reaction regimes. We present evidence of radiation reaction in the collision of an ultrarelativistic electron beam generated by laser-wakefield acceleration (ɛ >500 MeV ) with an intense laser pulse (a0>10 ). We measure an energy loss in the postcollision electron spectrum that is correlated with the detected signal of hard photons (γ rays), consistent with a quantum description of radiation reaction. The generated γ rays have the highest energies yet reported from an all-optical inverse Compton scattering scheme, with critical energy ɛcrit>30 MeV .

  4. Experimental Evidence of Radiation Reaction in the Collision of a High-Intensity Laser Pulse with a Laser-Wakefield Accelerated Electron Beam

    Directory of Open Access Journals (Sweden)

    J. M. Cole

    2018-02-01

    Full Text Available The dynamics of energetic particles in strong electromagnetic fields can be heavily influenced by the energy loss arising from the emission of radiation during acceleration, known as radiation reaction. When interacting with a high-energy electron beam, today’s lasers are sufficiently intense to explore the transition between the classical and quantum radiation reaction regimes. We present evidence of radiation reaction in the collision of an ultrarelativistic electron beam generated by laser-wakefield acceleration (ϵ>500  MeV with an intense laser pulse (a_{0}>10. We measure an energy loss in the postcollision electron spectrum that is correlated with the detected signal of hard photons (γ rays, consistent with a quantum description of radiation reaction. The generated γ rays have the highest energies yet reported from an all-optical inverse Compton scattering scheme, with critical energy ϵ_{crit}>30  MeV.

  5. Near-GeV-energy laser-wakefield acceleration of self-injected electrons in a centimeter-scale plasma channel

    International Nuclear Information System (INIS)

    Tsung, F.S.; Narang, Ritesh; Joshi, C.; Mori, W. B.; Fonseca, R. A.; Silva, L.O.

    2004-01-01

    The first three-dimensional, particle-in-cell (PIC) simulations of laser-wakefield acceleration of self-injected electrons in a 0.84 cm long plasma channel are reported. The frequency evolution of the initially 50 fs (FWHM) long laser pulse by photon interaction with the wake followed by plasma dispersion enhances the wake which eventually leads to self-injection of electrons from the channel wall. This first bunch of electrons remains spatially highly localized. Its phase space rotation due to slippage with respect to the wake leads to a monoenergetic bunch of electrons with a central energy of 0.26 GeV after 0.55 cm propagation. At later times, spatial bunching of the laser enhances the acceleration of a second bunch of electrons to energies up to 0.84 GeV before the laser pulse intensity is significantly reduced

  6. 2D hydrodynamic simulations of a variable length gas target for density down-ramp injection of electrons into a laser wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kononenko, O., E-mail: olena.kononenko@desy.de [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Lopes, N.C.; Cole, J.M.; Kamperidis, C.; Mangles, S.P.D.; Najmudin, Z. [The John Adams Institute for Accelerator Science, The Blackett Laboratory, Imperial College London, SW7 2BZ UK (United Kingdom); Osterhoff, J. [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Poder, K. [The John Adams Institute for Accelerator Science, The Blackett Laboratory, Imperial College London, SW7 2BZ UK (United Kingdom); Rusby, D.; Symes, D.R. [Central Laser Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Warwick, J. [Queens University Belfast, North Ireland (United Kingdom); Wood, J.C. [The John Adams Institute for Accelerator Science, The Blackett Laboratory, Imperial College London, SW7 2BZ UK (United Kingdom); Palmer, C.A.J. [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany)

    2016-09-01

    In this work, two-dimensional (2D) hydrodynamic simulations of a variable length gas cell were performed using the open source fluid code OpenFOAM. The gas cell was designed to study controlled injection of electrons into a laser-driven wakefield at the Astra Gemini laser facility. The target consists of two compartments: an accelerator and an injector section connected via an aperture. A sharp transition between the peak and plateau density regions in the injector and accelerator compartments, respectively, was observed in simulations with various inlet pressures. The fluid simulations indicate that the length of the down-ramp connecting the sections depends on the aperture diameter, as does the density drop outside the entrance and the exit cones. Further studies showed, that increasing the inlet pressure leads to turbulence and strong fluctuations in density along the axial profile during target filling, and consequently, is expected to negatively impact the accelerator stability.

  7. Harmonics generation of a terahertz wakefield free-electron laser from a dielectric loaded waveguide excited by a direct current electron beam.

    Science.gov (United States)

    Li, Weiwei; Lu, Yalin; He, Zhigang; Jia, Qika; Wang, Lin

    2016-06-01

    We propose to generate high-power terahertz (THz) radiation from a cylindrical dielectric loaded waveguide (DLW) excited by a direct-current electron beam with the harmonics generation method. The DLW supports a discrete set of modes that can be excited by an electron beam passing through the structure. The interaction of these modes with the co-propagating electron beam results in micro-bunching and the coherent enhancement of the wakefield radiation, which is dominated by the fundamental mode. By properly choosing the parameters of DLW and beam energy, the high order modes can be the harmonics of the fundamental one; thus, high frequency radiation corresponding to the high order modes will benefit from the dominating bunching process at the fundamental eigenfrequency and can also be coherently excited. With the proposed method, high power THz radiation can be obtained with an easily achievable electron beam and a large DLW structure.

  8. [Regularity of Clinical Application of Lianquan (CV 23) in Chinese Ancient Times According to Literature of Traditional Chinese Medicine].

    Science.gov (United States)

    Deng, Mei-Jun; Liu, Chun-Yan; Xie, Yu; Zhu, Jie-Bin; Xu, Zhen-Hua

    2018-03-25

    To summarize the regularity of application of Lianquan (CV 23) in clinical practice in Chinese ancient times through analysis of ancient traditional Chinese medical (TCM) literature. A total of 60 books involving CV 23 from the 1 156 ancient TCM books listed in the fifth edition of Encyclopedia of Traditional Chinese Medicine were collected by using CV 23 as the main keyword and "Sheben" "Benchi", and "Jieben" (the other names of CV 23 in TCM)as the supplementary keywords and analyzed systematically. A database was then constructed from the collected data, including the related types of disorders or symptoms, acupoint recipes, and methods of needling and moxibustion, contraindications, etc. A total of 196 articles related to the application of CV 23 from 60 ancient classical books were collected in accordance with the inclusive criteria. Among them, 155 articles are referred to the indications of CV 23, 35 to types of disorders such as asthma, cough, tongue swelling with difficulty in speaking, protracted tongue, acute contraction of tongue root, vomiting, spasm syndrome, stroke, aphtha, problems of mouth and teeth, throat problems, etc. of the internal medicine, surgery, pediatrics, and five-sense organs; 64 items are referred to the application of single CV 23, 91 to CV 23-included recipes containing 111 adjunct acupoints, and 78 to stimulation of CV 23 with acupuncture needle, moxibustion, pricking blood, and fire needle. Moreover, of the 111 adjunct acupoints, the most commonly used are Shaoshang (LU 11), Tiantu (CV 22), Hegu (LI 4), Yuye (EX-HN 13), Zhongchong (PC 9), etc. Lianquan (CV 23) is mainly used for glossopharyngeal problems chiefly by syndrome-meridian differentiation. The supplement of complementary acupoints or five-shu points in combination with CV 23 has a synergistic effect. Moxibustion (3 moxa- cones in general) is often employed, and the needling depth is usually about 7.5 mm. The common contraindication of CV 23 is severe tongue swelling.

  9. Conservação de tangerina cv. Clemenules utilizando diferentes recobrimentos = Conservation of Mandarins cv. Clemenules with different cuticles

    Directory of Open Access Journals (Sweden)

    Rosa de Oliveira Treptow

    2007-01-01

    Full Text Available O objetivo deste trabalho foi verificar os efeitos de diferentes recobrimentos e períodos de armazenamento na conservação de tangerinas Clemenules. Após a colheita, as frutas foram submetidas ao pré-resfriamento por 12 horas a 5ºC e em seguida, aos seguintes tratamentos: T1 testemunha; T2 filme de polietileno microperfurado; T3 filme de polietileno não perfurado; T4 cera de carnaúba a 50%, diluída em água; T5 cera de carnaúba a 100% (não diluída. As tangerinas foram armazenadas por 20, 40 e 60 dias em temperatura de 5ºC e UR de 90-95%, depois foram mantidas em temperatura de 15±1ºC e UR de 75-80%, durante quatro dias simulando a comercialização. Na colheita e após cada período de armazenamento, seguido de simulação decomercialização, foram avaliadas as variáveis: perda de massa; cor; sólidos solúveis (SS; acidez titulável (AT; relação SS/AT; podridões, distúrbios fisiológicos e características sensoriais. Amodificação da atmosfera reduziu a perda de massa, a incidência de distúrbios e podridões de tangerinas Clemenules durante o armazenamento. As frutas acondicionadas em filme de polietilenosem perfuração ou aquelas revestidas com cera sem diluição apresentaram sabor estranho e menor qualidade geral. Tangerinas ‘Clemenules’ acondicionadas em filme de polietileno microperfurado ecera diluída em 50% de água podem ser armazenadas durante 60 dias a 5ºC e comercializadas durante quatro dias a 15±1ºC sem comprometer a qualidade sensorial.The aim of this work was to evaluate the effects of different cuticles and storage periods on the conservation of mandarins cv. Clemenules. After harvest the fruits were kept at 5ºC during 12 hours. Then, they were submitted to the following treatments: T1 control; T2 micro perforated polyethylene bag; T3 non-perforated polyethylene bag; T4 carnauba wax at 50% in water; T5 carnauba wax at 100% (without dilution. The mandarins were stored for 20, 40 and 60 days at 5

  10. Produtividade e valor nutritivo da Brachiaria brizantha cv. Marandu em um sistema silvipastoril Productivity and nutritional value of Brachiaria brizantha cv. Marandu in a silvopastoral system

    Directory of Open Access Journals (Sweden)

    L.F. Sousa

    2007-08-01

    Full Text Available O experimento foi realizado em sistema silvipastoril (Ssp localizado no bioma de Cerrado, no município de Lagoa Santa, Minas Gerais, no ano agrícola de 2004-2005. Avaliou-se a influência do Ssp composto pela arbórea bolsa-de-pastor (Zeyheria tuberculosa sobre os parâmetros produção, atributos morfogênicos, composição bromatológica e valor nutritivo da gramínea Brachiaria brizantha cv. Marandu, e os efeitos sobre as condições microclimáticas. O delineamento experimental foi em blocos ao acaso, com cinco blocos (épocas de corte, dois tratamentos (T1 - B. brizantha cv. Marandu sombreada com a Z. tuberculosa e T2 - B. brizantha cv. Marandu, a pleno sol e três repetições (parcelas. O sombreamento proporcionado pela Z. tuberculosa, apesar de reduzir a produção de matéria seca (MS da gramínea, favoreceu o aumento do teor de proteina bruta (PB e não alterou a produção de PB/ha e nem afetou a concentração de FDN. Os teores de FDA foram mais altos que os encontrados a pleno sol, o que provavelmente resultou em menor degradabilidade in vitro da MS e da matéria orgânica, não alterando a degradabilidade efetiva.The experiment was carried out in a Silvopastoral system (Sps located in Brazilian Savannah, Lagoa Santa county, Minas Gerais State, during the agricultural year of 2004-2005. It was studied the influence of Sps formed by "Bolsa de Pastor" (Zeyheria tuberculosa on the production, morphogenic attributes, bromatological composition and nutritional value of the graminaceous Brachiaria brizantha cv. Marandu as well as on the microclimatic aspects. The Sps was established in 1982, in a red-yellow latossol by the natural regeneration process. The experiment was based on a randomized block design, with 5 blocks (cutting times, 2 treatments (T1 - B. brizantha cv. Marandu shaded by Z. tuberculosa and T2 - B. brizantha cv. Marandu at open sky and three repetitions (plots. Although the DM production of the graminaceous in the Sps

  11. FORMULASI STRATEGI PENINGKATAN PRODUKSI DOMBA CV MITRA TANI FARM, CIAMPEA, BOGOR

    Directory of Open Access Journals (Sweden)

    Amalia Sholehana

    2014-04-01

    Full Text Available ABSTRACTThis research was conducted to formulate to increase the sheep production at CV Mitra Tani Farm (CV MT Farm, Ciampea, Bogor. The research was conducted using descriptive analysis by analyzing the problem experienced by CV. MitraTani Farm. Primary data and secondary data were gathered at this research. The research was also conducted using several analytical methods such as value chain mapping, internal factor evaluation (IFE and external factor evaluation (EFE matrix, SWOT and quantitative strategic planning matrix (QSPM. Based on the value chain analysis, the current production of sheep at CV MT farm is highly depending on the supply from its partners and internal farmers. According to the IFE and EFE results, the differences of each weighted values were respectively 2,120 and 0,686 so the position of the company in the SWOT matrix was situated at Quadrant I. Therefore the company needs to use a growth strategy. The QSPM sequenced the strategy priority as follow (1 increasing the number of lambs, (2 developing the management, (3 strengthening the capital and ownership, (4 improving the quality through technology. The result of the gross profit margin calculation, if the sheep‘s selling is increased up to 1000 sheep per month then the possible annual profit that can be earned by CV MT farm is 40,34% of the total production.Keywords: MT Farm, sheep production, strategies, SWOT, QSPM, gross profit marginABSTRAKPenelitian ini dilakukan untuk memformulasikan strategi peningkatan produksi domba di CV Mitra Tani Farm (CV MT Farm, Ciampea, Bogor. Pendekatan penelitian yang diterapkan adalah analisis deskriptif yang dilakukan dengan mempelajari permasalahan dari objek yang diteliti. Data yang dikumpulkan dalam penelitian ini adalah data primer dan data sekunder. Penelitian dilakukan menggunakan alat analisis berupa pemetaan rantai nilai,  matriks IFE (Internal Factor Evaluation dan EFE (External Factor Evaluation, SWOT, dan QSPM (Quantitative

  12. 3CV+2: modelo de calidad para la construcción de la vivienda 3CV+2: quality model for dwelling construction

    Directory of Open Access Journals (Sweden)

    Salvador García Rodríguez

    2008-08-01

    Full Text Available Este artículo presenta el modelo y los resultados que, desde Junio de 2005, se han alcanzado en el desarrollo del Programa Nacional de Certificación de los Procesos Constructivos de la Vivienda en base al Modelo 3cv+2. El programa se ha desarrollado con base a un convenio entre el Tecnológico de Monterrey y la Cámara Nacional de la Industria de Desarrollo y Promoción de Vivienda. Actualmente se encuentran voluntariamente en el programa 52 empresas inmobiliarias de diferentes estados de la República Mexicana. El modelo de calidad 3cv+2 es una metodología que busca establecer en los niveles operativos de la construcción criterios que permitan reducir la variabilidad del proceso de construcción, y además permita de manera sistemática, y en un proceso de mejora continua, evaluar el desempeño de calidad en proyectos de construcción de vivienda. El modelo 3cv+2 define en su nombre el alcance del mismo, 3 criterios de calidad para la vivienda (insumos, proceso y producto, apoyado por 2 auditorías (+2, la auditoría interna de la propia empresa, mas la auditoría externa hecha por el Tecnológico de Monterrey. El modelo 3cv+2 busca garantizar que los insumos utilizados en la construcción de las viviendas sean de calidad superior, y que los procesos de ejecución posean características de calidad, productividad, eficiencia, racionalización, y estandarización; de tal manera que insumos y productos sean de alto valor agregado, y garanticen la calidad especificada en las etapas parciales y en la vivienda terminada.This paper presents the model and the results that have been achieved during the development of the National Quality Certification Program based on the model 3cv +2 from June 2005. This program has been developed based on an agreement between the Monterrey Tech and the National Chamber of Housing Industry. Nowadays, the program has 52 voluntary real estate companies from different states of Mexico. The 3cv+2 quality model is a

  13. Studies of frequency dependent C-V characteristics of neutron irradiated p+-n silicon detectors

    International Nuclear Information System (INIS)

    Li, Zheng; Kraner, H.W.

    1990-10-01

    Frequency-dependent capacitance-voltage fluence (C-V) characteristics of neutron irradiated high resistivity silicon p + -n detectors have been observed up to a fluence of 8.0 x 10 12 n/cm 2 . It has been found that frequency dependence of the deviation of the C-V characteristic (from its normal V -1/2 dependence), is strongly dependent on the ratio of the defect density and the effective doping density N t /N' d . As the defect density approaches the effective dopant density, or N t /N' d → 1, the junction capacitance eventually assumes the value of the detector geometry capacitance at high frequencies (f ≤ 10 5 Hz), independent of voltage. A two-trap-level model using the concept of quasi-fermi levels has been developed, which predicts both the effects of C-V frequency dependence and dopant compensation observed in this study

  14. Immobilization of enzymatic extracts of Portulaca oleracea cv. roots for oxidizing aqueous bisphenol A.

    Science.gov (United States)

    Matsushima, Kazuki; Kaneda, Hirokazu; Harada, Kazuo; Matsuura, Hideyuki; Hirata, Kazumasa

    2015-05-01

    Water pollution from the release of industrial wastewater is a serious problem for almost every industry. Enzymes from portulaca, Portulaca oleracea cv., have been investigated for their ability to degrade bisphenol A (BPA), one of the well-known estrogenic pollutants. Enzymatic crude extracts from P. oleracea cv. roots were immobilized on aminopropyl-modified glass beads. They maintained BPA metabolic activity over a broad range of pH values and temperatures. The immobilized enzyme was reusable with more than 50 % of its initial activity retained after 12 batch reactions and no loss of activity after storage for 1 month at -30 °C. Thus, the immobilization of extracts from P. oleracea cv. roots is a useful method for removing BPA from industrial wastewater.

  15. Light equation in eclipsing binary CV Boo: third body candidate in elliptical orbit

    Science.gov (United States)

    Bogomazov, A. I.; Kozyreva, V. S.; Satovskii, B. L.; Krushevska, V. N.; Kuznyetsova, Y. G.; Ehgamberdiev, S. A.; Karimov, R. G.; Khalikova, A. V.; Ibrahimov, M. A.; Irsmambetova, T. R.; Tutukov, A. V.

    2016-12-01

    A short period eclipsing binary star CV Boo is tested for the possible existence of additional bodies in the system with a help of the light equation method. We use data on the moments of minima from the literature as well as from our observations during 2014 May-July. A variation of the CV Boo's orbital period is found with a period of {≈}75 d. This variation can be explained by the influence of a third star with a mass of {≈}0.4 M_{⊙} in an eccentric orbit with e≈0.9. A possibility that the orbital period changes on long time scales is discussed. The suggested tertiary companion is near the chaotic zone around the central binary, so CV Boo represents an interesting example to test its dynamical evolution. A list of 14 minima moments of the binary obtained from our observations is presented.

  16. Segmentation of kidney using C-V model and anatomy priors

    Science.gov (United States)

    Lu, Jinghua; Chen, Jie; Zhang, Juan; Yang, Wenjia

    2007-12-01

    This paper presents an approach for kidney segmentation on abdominal CT images as the first step of a virtual reality surgery system. Segmentation for medical images is often challenging because of the objects' complicated anatomical structures, various gray levels, and unclear edges. A coarse to fine approach has been applied in the kidney segmentation using Chan-Vese model (C-V model) and anatomy prior knowledge. In pre-processing stage, the candidate kidney regions are located. Then C-V model formulated by level set method is applied in these smaller ROI, which can reduce the calculation complexity to a certain extent. At last, after some mathematical morphology procedures, the specified kidney structures have been extracted interactively with prior knowledge. The satisfying results on abdominal CT series show that the proposed approach keeps all the advantages of C-V model and overcome its disadvantages.

  17. Isotopic coherence of refractory inclusions from CV and CK meteorites: Evidence from multiple isotope systems

    Science.gov (United States)

    Shollenberger, Quinn R.; Borg, Lars E.; Render, Jan; Ebert, Samuel; Bischoff, Addi; Russell, Sara S.; Brennecka, Gregory A.

    2018-05-01

    Calcium-aluminum-rich inclusions (CAIs) are the oldest dated materials in the Solar System and numerous previous studies have revealed nucleosynthetic anomalies relative to terrestrial rock standards in many isotopic systems. However, most of the isotopic data from CAIs has been limited to the Allende meteorite and a handful of other CV3 chondrites. To better constrain the isotopic composition of the CAI-forming region, we report the first Sr, Mo, Ba, Nd, and Sm isotopic compositions of two CAIs hosted in the CK3 desert meteorites NWA 4964 and NWA 6254 along with two CAIs from the CV3 desert meteorites NWA 6619 and NWA 6991. After consideration of neutron capture processes and the effects of hot-desert weathering, the Sr, Mo, Ba, Nd, and Sm stable isotopic compositions of the samples show clearly resolvable nucleosynthetic anomalies that are in agreement with previous results from Allende and other CV meteorites. The extent of neutron capture, as manifested by shifts in the observed 149Sm-150Sm isotopic composition of the CAIs is used to estimate the neutron fluence experienced by some of these samples and ranges from 8.40 × 1013 to 2.11 × 1015 n/cm2. Overall, regardless of CAI type or host meteorite, CAIs from CV and CK chondrites have similar nucleosynthetic anomalies within analytical uncertainty. We suggest the region that CV and CK CAIs formed was largely uniform with respect to Sr, Mo, Ba, Nd, and Sm isotopes when CAIs condensed and that CAIs hosted in CV and CK meteorites are derived from the same isotopic reservoir.

  18. Khatyrka, a new CV3 find from the Koryak Mountains, Eastern Russia

    Science.gov (United States)

    MacPherson, Glenn J.; Andronicos, Christopher L.; Bindi, Luca; Distler, Vadim V.; Eddy, Michael P.; Eiler, John M.; Guan, Yunbin; Hollister, Lincoln S.; Kostin, Alexander; Kryachko, Valery; Steinhardt, William M.; Yudovskaya, Marina; Steinhardt, Paul J.

    2013-08-01

    A new meteorite find, named Khatyrka, was recovered from eastern Siberia as a result of a search for naturally occurring quasicrystals. The meteorite occurs as clastic grains within postglacial clay-rich layers along the banks of a small stream in the Koryak Mountains, Chukotka Autonomous Okrug of far eastern Russia. Some of the grains are clearly chondritic and contain Type IA porphyritic olivine chondrules enclosed in matrices that have the characteristic platy olivine texture, matrix olivine composition, and mineralogy (olivine, pentlandite, nickel-rich iron-nickel metal, nepheline, and calcic pyroxene [diopside-hedenbergite solid solution]) of oxidized-subgroup CV3 chondrites. A few grains are fine-grained spinel-rich calcium-aluminum-rich inclusions with mineral oxygen isotopic compositions again typical of such objects in CV3 chondrites. The chondritic and CAI grains contain small fragments of metallic copper-aluminum-iron alloys that include the quasicrystalline phase icosahedrite. One grain is an achondritic intergrowth of Cu-Al metal alloys and forsteritic olivine ± diopsidic pyroxene, both of which have meteoritic (CV3-like) oxygen isotopic compositions. Finally, some grains consist almost entirely of metallic alloys of aluminum + copper ± iron. The Cu-Al-Fe metal alloys and the alloy-bearing achondrite clast are interpreted to be an accretionary component of what otherwise is a fairly normal CV3 (oxidized) chondrite. This association of CV3 chondritic grains with metallic copper-aluminum alloys makes Khatyrka a unique meteorite, perhaps best described as a complex CV3 (ox) breccia.

  19. Mineralogy and Petrography of MIL 090001, a Highly Altered CV Chondrite from the Reduced Sub-Group

    Science.gov (United States)

    Keller, Lindsay P.

    2011-01-01

    MIL 090001 is a large (greater than 6 kg) CV chondrite from the reduced subgroup (CV(sub red)) that was recovered during the 2009-2010 ANSMET field season [1]. The CV(sub red) subgroup meteorites retain primitive characteristics and have escaped the Na and Fe meta-somatism that affected the oxidized (CV(sub ox)) subgroups. MIL 090001 is, however, reported to be altered [1], and thus a major objective of this study is to characterize its mineralogy and petrography and the extent of the alteration.

  20. Detoxification of microcystin-LR in water by Portulaca oleracea cv.

    Science.gov (United States)

    Isobe, Takatoshi; Okuhata, Hiroshi; Miyasaka, Hitoshi; Jeon, Bong-Seok; Park, Ho-Dong

    2014-03-01

    Microcystin-LR (0.02 μg/ml) in the hydroculture medium of Portulaca oleracea cv., became below the detection level (<0.0001 μg/ml) by HPLC analysis after 7 days. The toxicity of microcystin estimated with protein phosphatase inhibition assay, however, remained at 37% of the initial level, indicating that microcystin-LR was transformed by P. oleracea cv. into unknown compound(s) of lower toxicity. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  1. Agrobacterium-mediated transformation of Easter lily (Lilium longiflorum cv. Nellie White)

    Science.gov (United States)

    Conditions were optimized for transient transformation of Lilium longiflorum cv. Nellie White using Agrobacterium tumefaciens. Bulb scale and basal meristem explants were inoculated with A. tumefaciens strain AGL1 containing the binary vector pCAMBIA 2301 which has the uidA gene that codes for ß-gl...

  2. Possibility of Recombination Gain Increase in CV Ions at 4.0 nm Via Coherence

    Science.gov (United States)

    Luo, Y.; Morozov, A.; Gordon, D.; Sprangle, P.; Svidzinsky, A.; Xia, H.; Scully, M.; Suckewer, S.

    This paper is about the recent experimental results on amplification of the CV line in the "water window" at 4.03 nm from resonance transition to the ground level of He-like ions in recombination scheme. The indication of the amplification of the CV line has been observed when an elongated narrow plasma channel was created, where high intensity 100 fs beams, optimal for creating CV ions in high density plasma, was propagated up to 0.5-0.6 mm. Without channeling the effective plasma length was much shorter and there was no indication of amplification.The large interest in gain generation in He-like ions in the transition to ground state is due to the possibility of applying a recently developed theory of Lasing Without Inversion (LWI) in XUV and X-ray regions to largely increase the gain for such transitions. The presented results of the indication of CV line amplifications are being discussed from the point of view of using LWI as a superradiance gain increase, hence to construct a very compact soft X-ray laser in the "water window".The last part of the paper is related to the application of the ultra-intensive fs plasma laser, which is currently in the process of development by using stimulated Raman backscattering (SRBS) to create a plasma amplifier and compressor, as the pump for compact laser operating in the "water window" and also at shorter wavelengths.

  3. RADISH CV. MOKHOVSKIY IS A SOURCE OF MS- AND MF-LINES AT BREEDING FOR HETEROSIS

    Directory of Open Access Journals (Sweden)

    M. I. Fedorova

    2015-01-01

    Full Text Available Based on hybrid and inbreed population of radish cv. Mokhovskiy using CMS-ogura nine lines with 100% of male sterility and fertile maintainers were selected. Using the multiplex PCR, the presence of cytoplasm of Ogura type in ms-lines and its absence in mf-lines were confirmed.

  4. Limited geographic distribution of the novel cyclovirus CyCV-VN

    NARCIS (Netherlands)

    Le, Van Tan; de Jong, Menno D.; Nguyen, Van Kinh; Nguyen, Vu Trung; Taylor, Walter; Wertheim, Heiman F. L.; van der Ende, Arie; van der Hoek, Lia; Canuti, Marta; Crusat, Martin; Sona, Soeng; Nguyen, Hanh Uyen; Giri, Abhishek; Nguyen, Thi Thuy Chinh Bkrong; Ho, Dang Trung Nghia; Farrar, Jeremy; Bryant, Juliet E.; Tran, Tinh Hien; Nguyen, Van Vinh Chau; van Doorn, H. Rogier

    2014-01-01

    A novel cyclovirus, CyCV-VN, was recently identified in cerebrospinal fluid (CSF) from patients with central nervous system (CNS) infections in central and southern Vietnam. To explore the geographic distribution of this novel virus, more than 600 CSF specimens from patients with suspected CNS

  5. Automatic tracking of red blood cells in micro channels using OpenCV

    Science.gov (United States)

    Rodrigues, Vânia; Rodrigues, Pedro J.; Pereira, Ana I.; Lima, Rui

    2013-10-01

    The present study aims to developan automatic method able to track red blood cells (RBCs) trajectories flowing through a microchannel using the Open Source Computer Vision (OpenCV). The developed method is based on optical flux calculation assisted by the maximization of the template-matching product. The experimental results show a good functional performance of this method.

  6. Cherry Picking Robot Vision Recognition System Based on OpenCV

    Directory of Open Access Journals (Sweden)

    Zhang Qi Rong

    2016-01-01

    Full Text Available Through OpenCV function, the cherry in a natural environment image after image preprocessing, color recognition, threshold segmentation, morphological filtering, edge detection, circle Hough transform, you can draw the cherry’s center and circular contour, to carry out the purpose of the machine picking. The system is simple and effective.

  7. Production of calibration sources and/or radioactive tracers with the cyclotron CV-28

    International Nuclear Information System (INIS)

    Osso Junior, Joao Alberto

    1995-01-01

    The present stage of production of calibration sources and radioactive tracers with the Cyclotron CV-28 is described. Among the methods already developed special attention is given to the production of 57 Co, 109 Cd and 111 In. (author). 3 refs

  8. Lipid abnormalities in streptozotocin-diabetes: Amelioration by Morus indica L. cv Suguna leaves

    OpenAIRE

    Andallu, B.; Vinay Kumar, A. V.; Varadacharyulu, N. Ch.

    2009-01-01

    AIM: To observe the influence of mulberry (Morus indica L. cv Suguna) leaves on lipid abnormalities in STZ-diabetic rats. MATERIALS AND METHODS: Treatment with dried mulberry leaf powder for a period of 8 weeks in hyperglycemic and hyperlipidemic STZ-diabetic rats. RESULTS: Mulberry leaves regulated fasting blood glucose, ameliorated the abnormalities in lipid profile as indicated by significant (P

  9. Connected Vehicle Pilot Deployment Program, Comprehensive Installation Plan - WYDOT CV Pilot

    Science.gov (United States)

    2018-02-16

    The Wyoming Department of Transportation's (WYDOT) Connected Vehicle (CV) Pilot Deployment Program is intended to develop a suite of applications that utilize vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) communication technology to re...

  10. NALISIS PENGAKUAN PENDAPATAN BERDASARKAN PSAK NOMOR 23 PADA CV TILZAK KABUPATEN PINRANG

    Directory of Open Access Journals (Sweden)

    ILHAM ARIFIN

    2017-05-01

    This research was conducted at CV. Tilzak Pinrang which is a business as a cog in the business of selling. Based on research that has been done, it is not all revenue recognition in accordance with IAS 23 is not dibuatkannya marked revenue balance sheet and income statement, so that the impact to the company's earnings were only included proceeds earned in one year.

  11. STRATEGI SEGMENTASI PASAR TERHADAP VOLUME PENJUALAN BUSANA MUSLIM PADA CV RABBANI ASYSA MAKASSAR

    OpenAIRE

    KARASE, HASNAWATI

    2014-01-01

    2014 Hasnawati Karase Haris Maupa Mukhtar Penelitian ini bertujuan untuk menganalisis strategi segmentasi pasar terhadap volume penjualan busana muslim pada CV Rabbani Asysa Makassar. Data penelitian ini diperoleh dari kuesioner (primer) mengenai segmentasi pasar Rabbani Makassar dengan mengambil sampel sebanyak 75 responden. Temuan penelitian ini menunjukkan bahwa variabel strategi segmentasi pasar yang terdiri dari segmentasi geografis, segmentasi demografis, segm...

  12. In vitro multiplication of banana (Musa sp.) cv. Grand Naine | Ahmed ...

    African Journals Online (AJOL)

    A micropropagation method is described for banana (Musa Spp.) Cv. Grand Naine. Suckers were surface sterilized with HgCl2 (0.1%) for 6 min which gave minimum contamination with maximum culture establishment. Of various treatment combinations, Murashige and Skoog (MS) medium + BAP 4.00 mg/l with IAA 2.00 ...

  13. PlantCV v2: Image analysis software for high-throughput plant phenotyping

    Directory of Open Access Journals (Sweden)

    Malia A. Gehan

    2017-12-01

    Full Text Available Systems for collecting image data in conjunction with computer vision techniques are a powerful tool for increasing the temporal resolution at which plant phenotypes can be measured non-destructively. Computational tools that are flexible and extendable are needed to address the diversity of plant phenotyping problems. We previously described the Plant Computer Vision (PlantCV software package, which is an image processing toolkit for plant phenotyping analysis. The goal of the PlantCV project is to develop a set of modular, reusable, and repurposable tools for plant image analysis that are open-source and community-developed. Here we present the details and rationale for major developments in the second major release of PlantCV. In addition to overall improvements in the organization of the PlantCV project, new functionality includes a set of new image processing and normalization tools, support for analyzing images that include multiple plants, leaf segmentation, landmark identification tools for morphometrics, and modules for machine learning.

  14. The influence of virus diseases on grape polyphenols of cv. 'Refosk'

    International Nuclear Information System (INIS)

    Tomazic, I.; Vrhovsek, U.; Korosec-Koruza, Z.

    2003-01-01

    External stimuli such as microbial infections, ultraviolet radiation, and chemical stressors can modulate the synthesis of polyphenols in the plants. Cv. 'Refosk' was used to show the influence of the GLRaV-1 and rugose wood (RW) on the polyphenols in grape. The infection shifted polyphenols from seeds to grape skins but had no impact on anthocyanins

  15. Endogenous auxin regulates the sensitivity of Dendrobium (cv. Miss Teen) flower pedicel abscission to ethylene

    NARCIS (Netherlands)

    Rungruchkanont, K.; Ketsa, S.; Chatchawankanphanich, O.; Doorn, van W.G.

    2007-01-01

    Dendrobium flower buds and flowers have an abscission zone at the base of the pedicel (flower stalk). Ethylene treatment of cv. Miss Teen inflorescences induced high rates of abscission in flower buds but did not affect abscission once the flowers had opened. It is not known if auxin is a regulator

  16. ANALISIS SEWA MENYEWA PARALEL PADA PERUSAHAAN RENT CAR CV. HARKAT DALAM PERSPEKTIF EKONOMI ISLAM

    Directory of Open Access Journals (Sweden)

    Samsuardi Samsuardi

    2013-12-01

    Full Text Available This study aims at determining the parallel process of car rental agreement between Harkat Rent Car Company and the owner of the car, and between the company and its customers in an Islamic economics perspective. This study also aims to analyze the risk coverage of the leased car. The data for this study was gathered through interviews, observation and documentation studies. The collected data was then analyzed using descriptive analysis method. Results showed that the process of car leasing begin when customer rented a car from CV. Harkat which was owned by its partner. The company provided a shared price for car owners according to a mutual agreement and applied only for a certain period. Furthermore, the partner has to allocate 20 percent of the income for the company. In addition, the company also required the partner to cover for maintenance costs, insurance, equipment, and spare parts. In the context of Islamic economics, the practice of leasing parallel conducted by the company was not fully Shariah compliance due to practice a lease above a lease and using two contracts in one transaction. =========================================== Penelitian ini bertujuan untuk mengetahui perjanjian sewa menyewa mobil secara paralel antara Perusahaan Rent Car CV. Harkat dengan pemilik mobil dan dengan konsumennya dalam perspektif ekonomi Islam. Penelitian ini juga bertujuan untuk menanganalisis pertanggungan resiko terhadap mobil yang dijadikan objek sewa menyewa tersebut sewa menyewa mobil di Perusahaan Rent Car CV. Data untuk penelitian ini bersumber dari wawancara, obesrvasi dan studi dokumentasi. Metode yang digunakan dalam penelitian ini adalah deskriptif analisis. Hasil penelitian menunjukkan bahwa CV. Harkat menyewakan mobil milik mitra kerjanya (pemilik mobil kepada pelanggan yang membutuhkan sewa mobil untuk keperluannya. Pemilik usaha memberikan harga kongsi kepada pemilik mobil sesuai dengan kesepakatan bersama dan untuk jangka waktu

  17. TENCompetence Learning Design Toolkit, Runtime component, ccsi_v3_2_10c_v1_4

    NARCIS (Netherlands)

    Sharples, Paul; Popat, Kris; Llobet, Lau; Santos, Patricia; Hernández-Leo, Davinia; Miao, Yongwu; Griffiths, David; Beauvoir, Phillip

    2010-01-01

    Sharples, P., Popat, K., Llobet, L., Santos, P., Hernandez-Leo, D., Miao, Y., Griffiths, D. & Beauvoir, P. (2009) TENCompetence Learning Design Toolkit, Runtime component, ccsi_v3_2_10c_v1_4 This release is composed of three files corresponding to CopperCore Service Integration (CCSI) v3.2-10cv1.4,

  18. ANALISIS KEBUTUHAN TENAGA KERJA RESERVASI TERHADAP PERENCANAAN PENGEMBANGAN SUMBER DAYA MANUSIA PADA CV. CAN TOUR & TRAVEL

    Directory of Open Access Journals (Sweden)

    Maya Christina

    2017-01-01

    Full Text Available Employment remains the fundamental probel faced by many countries including Indonesia. One of the efforts the Government of Indonesia in extending employment opportunities is to develop the tourism sector. Bali is one of the potential tourist destinastions and it needs to be marketed. Cooperation between the Travel Bureau with the provider of the accommodation or hotel is one of the ways the potential market and the most instrumental in the development of the company, namely human resources required or called by labor. CV. CAN Tour and Travel is one of the tourist industry in Bali trip with a number of guest handling that quite a lot. This research aims to know the availability of labor needs resevartion in order CV. CAN Tour and Travel development and also to find out how the workforce qualification is required. Determination technique using the key informant that was labor reservation CV. CAN Tour and Travel, while the base of the informant was CV. CAN Tour and Travel Manager. Data analysis technique used is the analysis of workload and workforce needs analysis. The research results obtained indicate that shortage of time working as many as 210 minutes. So the manpower needed by CV. CAN Tour and Travel is two people with the fact that there is only 1 nowaday. It can be seen from the burden of the work done in a day’s work and the workforce absences. So labor needs on the Reservation Department is supposed to be 3 people, with 2 staff 1 reservations and ticketing staff. It was necessary increase manpower in the Labour Departmen’s Reservation in the reservation and also training to develop the ability to work.

  19. Comportamento agronômico inicial da cv. Chimarrita enxertada em cinco porta-enxertos de pessegueiro Agronomical behavior of cv. Chimarrita on five rootstocks of peach trees

    Directory of Open Access Journals (Sweden)

    Moacir da Silva Rocha

    2007-01-01

    Full Text Available O trabalho teve por objetivo avaliar a resposta agronômica da cv. Chimarrita enxertada em cinco porta-enxertos, nas condições edafoclimáticas da região de Pelotas-RS, no período de 2003 a 2005. Durante o período de execução do experimento, foram avaliados o diâmetro do tronco do porta-enxerto e da cultivar-copa, comprimento médio dos ramos principais, volume de copa, massa fresca e massa seca do material vegetal retirado nas podas verde e de inverno, índice de intensidade de poda, massa média dos frutos, produção por planta, eficiência produtiva, produção por hectare, sólidos solúveis totais, firmeza da polpa, diâmetro e coloração dos frutos. O porta-enxerto 'Capdeboscq' induziu o maior crescimento vegetativo na cv. Chimarrita durante os três anos de avaliação, seguido do porta-enxerto 'Okinawa'. Este, por sua vez, induziu o maior rendimento produtivo (1,65 t ha-1. A cv. Capdeboscq proporcionou a obtenção de frutos com maior massa. Os porta-enxertos 'GF 305' e 'Aldrighi' induziram menor desenvolvimento vegetativo e a mais baixa produtividade (0,52 t.ha-1 .The objective for this study was to evaluate the agronomical behavior of cv. Chimarrita on five rootstocks of peach trees in Pelotas- RS from 2003 to 2005. The variables evaluated were: trunk diameters of the rootstock and of the scion; length of the annual terminal growth; volume of the canopy; fresh and dry weight of the material taken by the summer and winter pruning; pruning intensity index; fruit weight; fruit production per tree; production efficiency; productivity per hectare; total soluble solids; pulp firmness; and fruit diameter and color. It was observed that the trees from: rootstock 'Capdeboscq' promoted higher vegetative growth and larger fruits, followed by the ones from the rootstock 'Okinawa' which promoted the highest yield (1, 65 t.ha-1; the rootstock 'GF 305' and 'Aldrighi' had the lowest vegetative development and yield (0, 52 t.ha-1.

  20. Hosing Instability of the Drive Electron Beam in the E157 Plasma-Wakefield Acceleration Experiment at the Stanford Linear Accelerator

    International Nuclear Information System (INIS)

    Blue, Brent Edward

    2005-01-01

    In the plasma-wakefield experiment at SLAC, known as E157, an ultra-relativistic electron beam is used to both excite and witness a plasma wave for advanced accelerator applications. If the beam is tilted, then it will undergo transverse oscillations inside of the plasma. These oscillations can grow exponentially via an instability know as the electron hose instability. The linear theory of electron-hose instability in a uniform ion column predicts that for the parameters of the E157 experiment (beam charge, bunch length, and plasma density) a growth of the centroid offset should occur. Analysis of the E157 data has provided four critical results. The first was that the incoming beam did have a tilt. The tilt was much smaller than the radius and was measured to be 5.3 (micro)m/(delta) z at the entrance of the plasma (IP1.) The second was the beam centroid oscillates in the ion channel at half the frequency of the beam radius (betatron beam oscillations), and these oscillations can be predicted by the envelope equation. Third, up to the maximum operating plasma density of E157 (∼2 x 10 14 cm -3 ), no growth of the centroid offset was measured. Finally, time-resolved data of the beam shows that up to this density, no significant growth of the tail of the beam (up to 8ps from the centroid) occurred even though the beam had an initial tilt

  1. Hosing Instability of the Drive Electron Beam in the E157 Plasma-Wakefield Acceleration Experiment at the Stanford Linear Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Blue, Brent Edward; /SLAC /UCLA

    2005-10-10

    In the plasma-wakefield experiment at SLAC, known as E157, an ultra-relativistic electron beam is used to both excite and witness a plasma wave for advanced accelerator applications. If the beam is tilted, then it will undergo transverse oscillations inside of the plasma. These oscillations can grow exponentially via an instability know as the electron hose instability. The linear theory of electron-hose instability in a uniform ion column predicts that for the parameters of the E157 experiment (beam charge, bunch length, and plasma density) a growth of the centroid offset should occur. Analysis of the E157 data has provided four critical results. The first was that the incoming beam did have a tilt. The tilt was much smaller than the radius and was measured to be 5.3 {micro}m/{delta}{sub z} at the entrance of the plasma (IP1.) The second was the beam centroid oscillates in the ion channel at half the frequency of the beam radius (betatron beam oscillations), and these oscillations can be predicted by the envelope equation. Third, up to the maximum operating plasma density of E157 ({approx}2 x 10{sup 14} cm{sup -3}), no growth of the centroid offset was measured. Finally, time-resolved data of the beam shows that up to this density, no significant growth of the tail of the beam (up to 8ps from the centroid) occurred even though the beam had an initial tilt.

  2. Fox grape cv. Bordô (Vitis labrusca L. and grapevine cv. Chardonnay (Vitis vinifera L. cultivated in vitro under different carbohydrates, amino acids and 6-Benzylaminopurine levels

    Directory of Open Access Journals (Sweden)

    Dayse Cristina de Carvalho

    2013-04-01

    Full Text Available The aim of this work was to study the influence of sucrose and glucose, amino acids and BAP (6-Benzylaminopurine levels on in vitro shoot regeneration of fox grape cv. Bordô and grapevine cv. Chardonnay. The nodal segments from micropropagated material were used as explants and half-strength MS medium as the basal medium. Sucrose and glucose at 15, 30 and 45 g.L-1 were tested as a carbon source and the supplementation of adenine, asparagine, alanine, glycine, cysteine, glutamine, arginine was tested at 40 g.L-1. The BAP levels (1 and 5 μM in solid and double-phase media were evaluated and compared with a control medium without BAP. Bordô had best in vitro growth than Chardonnay. Sucrose was a better carbohydrate source than glucose for both the cultivars. Bordô and Chardonnay had different amino acid preferences for some parameters. In conclusion, for in vitro shoot regeneration from the nodal segments, culture on solid medium with 5 μM BAP, 15 g.L-1 sucrose for Bordô and 45 g.L-1 sucrose for Chardonnay showed better results. Similarly, the supplementation of 40 g.L-1 arginine for Bordô and 40 g.L-1 arginine or glycine for Chardonnay showed better results.

  3. Effect of mechanical damage and wound healing on the viscoelastic properties of stems of flax cultivars (Linum usitatissimum L. cv. Eden and cv. Drakkar).

    Science.gov (United States)

    Paul-Victor, Cloé; Dalle Vacche, Sara; Sordo, Federica; Fink, Siegfried; Speck, Thomas; Michaud, Véronique; Speck, Olga

    2017-01-01

    As plant fibres are increasingly used in technical textiles and their composites, underlying principles of wound healing in living plant fibres are relevant to product quality, and provide inspiration for biomimetic healing in synthetic materials. In this work, two Linum usitatissimum cultivars differing in their stem mechanical properties, cv. Eden (stems resistant to lodging) and cv. Drakkar (with more flexible stems), were grown without wound or with stems previously wounded with a cut parallel or transversal to the stem. To investigate wound healing efficiency, growth traits, stem biomechanics with Dynamic Mechanical Analysis and anatomy were analysed after 25-day recovery. Longitudinal incisions formed open wounds while transversal incisions generated stem growth restoring the whole cross-section but not the original stem organisation. In the case of transversal wound healing, all the bast fibre bundles in the perturbed area became lignified and pulled apart by parenchyma cells growth. Both Linum cultivars showed a healing efficiency from 79% to 95% with higher scores for transversal healing. Morphological and anatomical modifications of Linum were related to mechanical properties and healing ability. Alongside with an increased understanding of wound healing in plants, our results highlight their possible impact on textile quality and fibre yield.

  4. Effect of inoculation and nitrogen top-dressing on yields and fodder value of winter pea cv. Maksimirski ozimi in triticale cv. Clercal mixture

    Directory of Open Access Journals (Sweden)

    Darko Uher

    2006-07-01

    Full Text Available Two year field trials (1999-2001 were aimed to determine the inoculation seed winter pea and nitrogen top-dressing effect on number and active nodules of pea root and also on the green mass and dry matter yield of winter pea cv. Maksimirski ozimi and triticale cv. Clercal mixture. Immediately before sowing the inoculation of pea seeds was done by the indigenous variety of Rhizobium leguminosarum bv. viciae which belongs to the collection of Department of Microbiology at the Faculty of Agriculture University of Zagreb. The highest total nodule number on pea root (134 was determined on the inoculated variant as well as active nodule (120. Average mixture green mass yields were ranging from 20.9 t ha-1 (control up to 30.1 t ha-1 (inoculation + nitrogen top-dressing. Total dry matter yields were ranging from 3.71 t ha-1 (control up to 5.36 t ha-1 (nitrogen top-dressing. Pea crude protein yields in 2001 were ranging from 500 kg ha-1 (nitrogen top-dressing up to 642 kg ha-1 (inoculation and for triticale, those values were from 322 kg ha-1 (control up to 498 kg ha-1 (nitrogen top-dressing. Total mixture crude proteins yields were from 845 kg ha-1 (control up to 998 kg ha-1 (nitrogen top-dressing.

  5. Effect of inoculation and nitrogen top-dressing on yields and fodder value of winter pea cv. Maksimirski ozimi in wheat cv. Sana mixture

    Directory of Open Access Journals (Sweden)

    Darko Uher

    2007-06-01

    Full Text Available Two year field trials (1999 - 2001 were performed to determine theinoculation seed winter pea and nitrogen top-dressing effect on number and active nodules of pea root and also on the green mass and dry matter yield of winter pea cv. Maksimirski ozimi and wheat cv. Sana mixture. Immediately before sowing the inoculation of pea seeds was accomplished by the indigenous variety of Rhizobium leguminosarum bv. viciae which belongs to the collection of Department of Microbiology at the Faculty of Agriculture University of Zagreb. The highest total nodule number on pea root (159 was determined on the inoculated variant as well as active nodule 144. Average mixture green mass yield were ranging from 24,65 t ha-1 (control up to 35,50 t ha-1 (inoculation. Total dry matter yields were ranging from 3,93 t ha-1 (control up to 5,66 t ha-1 (inoculation. Yields crude proteins pea in 2001 were ranging from 692 kg ha-1 (control up to 1058 kg ha-1 (inoculation and for wheat, those values ranged from 199 kg ha-1 (control up to 454 kg ha-1 (nitrogen top-dressing. Total crude proteins mixture yields were in range from 891 kg ha-1 (control up to 1360 kg ha-1 (inoculation.

  6. Avaliação da Brachiaria brizantha cv. marandu em sistemas silvipastoris Evaluation of Brachiaria brizantha cv. marandu in silvopastoral systems

    Directory of Open Access Journals (Sweden)

    G.R. Moreira

    2009-06-01

    Full Text Available Avaliou-se a degradabilidade in situ da matéria seca (MS da Brachiaria brizantha cv. marandu colhida em dois sistemas silvipastoris compostos pelas arbóreas, ipê felpudo (Zeyheria tuberculosa e aroeira (Myracrodruon urundeuva, localizados no bioma Cerrado, município de Lagoa Santa, MG. O período de coleta da forragem foi de dezembro de 2004 a abril de 2005. O delineamento utilizado foi em blocos ao acaso, segundo esquema de parcelas subdivididas, sendo as parcelas os tratamentos e as sub-parcelas os tempos de degradação. O sombreamento com as arbóreas não influenciou a degradabilidade in situ da matéria seca da forrageira.In situ degradability of dry matter of Brachiaria brizantha cv. marandu harvested in two silvopastoral systems was evaluated. One system was composed by Zeyheria tuberculosa tree and the other by Myracrodruon urundeuva, both located at Brazilian Savannah, Lagoa Santa, MG. A completely ramdomized block experimental design in a splitplot arrangement was used. The treatments were allocated in the plots and the times in the splitplot. No effect of shade was observed for in situ dry matter degradability.

  7. Thermal stability of oils added with avocado (Persea americana cv. Hass) or olive (Olea europaea cv. Arbequina) leaf extracts during the French potatoes frying.

    Science.gov (United States)

    Jiménez, Paula; García, Paula; Bustamante, Andrés; Barriga, Andrés; Robert, Paz

    2017-04-15

    Effect of the addition of avocado (Persea americana cv. Hass) or olive (Olea europaea cv. Arbequina) hydroalcoholic leaf extracts (AHE and OHE, respectively) on thermal stability of canola oil (CO) and high oleic sunflower oil (HOSO) during French potatoes frying at 180°C was studied. The extracts were characterized by the total phenolic content, phenol chromatographic profiles and antioxidant activity. B-type trimer procyanidins were the major phenolic compounds identified in AHE. OHE showed higher phenol content, antioxidant activity regarding AHE. CO+OHE and HOSO+OHE decreased the formation of polar compounds and showed an anti-polymeric effect with respect to oils without extracts, whereas AHE extract showed a prooxidant effect on HOSO. Therefore, OHE showed an antioxidant effect on HOSO and CO under the studied conditions. In addition, all systems (CO+AHE, HOSO+AHE, CO+OHE and HOSO+OHE) increased the retention of tocopherols. These results demonstrate the potential utility of OHE as natural antioxidant for oils. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Efeito de reguladores de crescimento em uva apirênica, cv. BRS Clara Effect of growth regulators on the seedless grape cv. BRS Clara

    Directory of Open Access Journals (Sweden)

    Jair Costa Nachtigal

    2005-08-01

    Full Text Available O presente trabalho teve por objetivo verificar o efeito da aplicação de diferentes concentrações do ácido giberélico (AG3, do thidiazuron (TDZ e do forchlorfenuron (CPPU no aumento do tamanho dos cachos e das bagas e no teor de sólidos solúveis totais de uva sem semente, cv. BRS Clara. As plantas foram conduzidas no sistema de latada, sobre o porta-enxerto IAC 572, no espaçamento 2,5 x 2,0m e com irrigação por microaspersão. Os experimentos foram conduzidos na Estação Experimental de Viticultura Tropical, da Embrapa Uva e Vinho, em Jales-SP. Os reguladores de crescimento foram aplicados via pulverização localizada no cacho, utilizando-se de concentrações de 0 a 4mg.L-1 de CPPU; 0 a 10mg.L-1 de TDZ, e de 0 a 90mg.L-1 de AG3, isolados ou em conjunto. De modo geral, a aplicação dos reguladores de crescimento promove a melhoria da qualidade dos cachos da cv. BRS Clara; o uso do TDZ e do CPPU em conjunto com o AG3 produz um efeito sinérgico, proporcionando melhor resposta do que o uso isolado do AG3; os tratamentos com 60mg.L-1 de AG3; 20mg.L-1 de AG3 + 4mg.L-1 de CPPU, e 10mg.L-1 de AG3 + 5mg.L-1 de TDZ proporcionam os melhores resultados para o aumento do diâmetro das bagas; a aplicação de AG3 antes da floração da cv. BRS Clara provoca abortamento excessivo, reduzindo a qualidade comercial dos cachos; a utilização de concentrações elevadas dos reguladores reduz o teor de sólidos solúveis totais.The objective of this study was to evaluate the effect of different concentrations of gibberellic acid (AG3, thidiazuron (TDZ and forchlorfenuron (CPPU on the size of bunches and berries and on the total soluble solids content, when applied in different concentrations on the seedless grapes, cv. BRS Clara. The grapevines were grafted on the rootstock IAC 572, trained in the pergola system and, spaced 2.5 x 2.0m and irrigated by micro sprinklers. The experiments were carried out at the Embrapa Grape and Wine Experimental

  9. Modificação da atmosfera na qualidade pós-colheita de ameixas cv. Reubennel Modified atmosphere on postharvest quality of plums cv. Reubennel

    Directory of Open Access Journals (Sweden)

    Marcelo Barbosa Malgarim

    2005-12-01

    Full Text Available Ameixas, de modo geral, têm curto período de conservação pós-colheita, havendo necessidade de otimizar as condições de colheita e de armazenamento. Este trabalho objetivou avaliar o efeito de diferentes modificadores de atmosfera, durante o armazenamento refrigerado, na qualidade pós-colheita de ameixas cv. Reubennel. Frutas no estádio de maturação meio-maduro foram submetidas aos seguintes modificadores de atmosfera: filmes de polietileno de 12,5 e 15µm de espessura e cera à base de carnaúba e avaliadas após 10; 20; 30 e 40 dias de armazenamento a 0ºC e UR de 90-95%. Avaliaram-se a perda de massa, cor, firmeza da polpa, pH, sólidos solúveis (SS, acidez titulável (AT, relação SS/AT, incidência de podridões, escurecimento interno e características sensoriais. Essas avaliações foram realizadas 3 dias após a retirada das frutas da câmara fria. Verificou-se que a cera à base de carnaúba GARFRESH N (BL9,5, sem diluição, e filmes de polietileno de 12,5 e 15µm reduziram a perda de massa, porém são impróprios para a modificação da atmosfera, em ameixas cv. Reubennel durante o armazenamento refrigerado. Ameixas cv. Reubennel mantêm a qualidade quando armazenadas durante 30 dias a 0ºC sem atmosfera modificada.Plums quickly loose postharvest quality, which makes imperative to optimize harvest and storage conditions. The objective of this work was to determine the effects of various atmosphere modifiers on the postharvest quality of cold storage plums, cv. Reubennel. Semi-mature fruits were stored under the following atmosphere modifiers conditions: polyethylene films 12,5 or 15µm of thickness; or carnauba wax. After submitted to these conditions the fruits were stored for 10, 20, 30 and 40 days in a cold room at 0ºC and 90-95% RH. Three days after taken out from the cold storage, the fruits were evaluated about: weight loss; color; firmness; pH; soluble solids (SS; titratable acidity (TA; SS/TA ratio; incidence of

  10. An improved technique for quasi-static C-V measurements

    International Nuclear Information System (INIS)

    Turan, R.; Finstad, T.G.

    1990-10-01

    A new automated quasi-static C-V measurement technique for MOS capacitors has been developed. This techniques uses an integrating electrometer to measure the charge accumulated on a MOS capacitor in response of a small voltage step. Making use of the internal data storage system of a commercial electrometer and a personal computer, the charge Q on the MOS capacitor is measured as a function of time t and stored. The capacitance is then obtained by analyzing this Q-t data set. A Si MOS sample is measured and analyzed in terms of interface charges as an example. Advantages over a commercial quasi-static meter which uses similar measurement technique are presented. It is also shown that this technique is potentially capable of measuring both high and low frequency C-V curves simultaneously. 9 refs. 5 figs

  11. Sensitivity of Phaseolus vulgaris cv. `CIAP 7247F' plants to Glufosinate ammonium herbicide in greenhouse

    Directory of Open Access Journals (Sweden)

    Idalmis Bermúdez-Caraballoso

    2014-01-01

    Full Text Available Genetic breeding in Phaseolus by genetic transformation requires an efficient selection system. The present investigation was aimed to determine the minimum lethal concentration of glufosinate-ammonium (Finale ® in beans plants cv. `CIAP 7247F' grown in greenhouse. Different concentrations of the herbicide were applied to the foliage of plants in acclimatization phase (20, 30 y 40 mg l-1 and the control. Results showed that the minimum lethal concentration in plants in acclimatization phase was 30 mg l-1. Results also demonstrated that is possible the use of the herbicide as a selective agent of beans transformants cv. `CIAP 7247F' carrying the bar gene. Keywords: genetic transformation, herbicide, selective agent, tissue culture

  12. Diagnosis of Elevator Faults with LS-SVM Based on Optimization by K-CV

    Directory of Open Access Journals (Sweden)

    Zhou Wan

    2015-01-01

    Full Text Available Several common elevator malfunctions were diagnosed with a least square support vector machine (LS-SVM. After acquiring vibration signals of various elevator functions, their energy characteristics and time domain indicators were extracted by theoretically analyzing the optimal wavelet packet, in order to construct a feature vector of malfunctions for identifying causes of the malfunctions as input of LS-SVM. Meanwhile, parameters about LS-SVM were optimized by K-fold cross validation (K-CV. After diagnosing deviated elevator guide rail, deviated shape of guide shoe, abnormal running of tractor, erroneous rope groove of traction sheave, deviated guide wheel, and tension of wire rope, the results suggested that the LS-SVM based on K-CV optimization was one of effective methods for diagnosing elevator malfunctions.

  13. Camera calibration method of binocular stereo vision based on OpenCV

    Science.gov (United States)

    Zhong, Wanzhen; Dong, Xiaona

    2015-10-01

    Camera calibration, an important part of the binocular stereo vision research, is the essential foundation of 3D reconstruction of the spatial object. In this paper, the camera calibration method based on OpenCV (open source computer vision library) is submitted to make the process better as a result of obtaining higher precision and efficiency. First, the camera model in OpenCV and an algorithm of camera calibration are presented, especially considering the influence of camera lens radial distortion and decentering distortion. Then, camera calibration procedure is designed to compute those parameters of camera and calculate calibration errors. High-accurate profile extraction algorithm and a checkboard with 48 corners have also been used in this part. Finally, results of calibration program are presented, demonstrating the high efficiency and accuracy of the proposed approach. The results can reach the requirement of robot binocular stereo vision.

  14. Automatic segmentation of Leishmania parasite in microscopic images using a modified CV level set method

    Science.gov (United States)

    Farahi, Maria; Rabbani, Hossein; Talebi, Ardeshir; Sarrafzadeh, Omid; Ensafi, Shahab

    2015-12-01

    Visceral Leishmaniasis is a parasitic disease that affects liver, spleen and bone marrow. According to World Health Organization report, definitive diagnosis is possible just by direct observation of the Leishman body in the microscopic image taken from bone marrow samples. We utilize morphological and CV level set method to segment Leishman bodies in digital color microscopic images captured from bone marrow samples. Linear contrast stretching method is used for image enhancement and morphological method is applied to determine the parasite regions and wipe up unwanted objects. Modified global and local CV level set methods are proposed for segmentation and a shape based stopping factor is used to hasten the algorithm. Manual segmentation is considered as ground truth to evaluate the proposed method. This method is tested on 28 samples and achieved 10.90% mean of segmentation error for global model and 9.76% for local model.

  15. Vigor tests to evaluate the physiological quality of corn seeds cv. 'Sertanejo'

    Directory of Open Access Journals (Sweden)

    Daniela Vieira dos Anjos Sena

    Full Text Available ABSTRACT: The vigor tests are intended to monitor the quality of seeds as it allows reliably distinguish lots of low and high vigor, providing additional information to the germination test. So in this study the objective was to identify the most efficient vigor tests on stratification of lots of corn seeds cv. 'Sertanejo'. The experiment was conducted at Laboratory of Seed Analysis at the Center of agricultural Science of the Universidade Federal da Paraíba, using samples from 20 seed lots in a completely randomized design. For characterization of the lots it was evaluated water content, germination and vigor (cold test, electrical conductivity, accelerated aging, seedling emergence in field and germination at low temperatures. The accelerated aging, electrical conductivity and field emergence of seedlings tests are the most efficient for classification of lots of corn seeds cv. 'Sertanejo' in levels of vigor, been the seeds of lot 1 the most vigorous.

  16. ANALISIS WANPRESTASI KEAGENAN PENJUALAN KENDARAAN BERMOTOR (Studi CV Nobel Perdana Kabupaten Tulang Bawang

    Directory of Open Access Journals (Sweden)

    Heri Yulianto

    2017-03-01

    Full Text Available Standard by PT Sumber Trada Motor leads to no availability of vehicles to be sold by outlets CV Nobel Perdana. Giving great discounts and gifts, making consumers tend to buy directly from outlets PT Sumber Trada Motor. This agency system turns into competition due to the sales and market share CV Nobel Perdana excellent. The usefulness of this study as a researcher competence in the field of business law violations agreement. The problem of research is how the legal provisions breach agreement, the implementation of competition law to businesses which violate the agreement. Is expected to the Government through the KPPU to crack down on employers who violate the law No. 5 of 1999 on Competition, so as to control the businesses that destroy the independence of other businesses.   Keywords: Standard, Agreement, Agency

  17. Potato cv. Romano reaction to primary and secondary infection with potato necrotic strain Y virus (PVYNTN

    Directory of Open Access Journals (Sweden)

    Drago Milošević

    2015-01-01

    Full Text Available Primary and secondary infections with PVYNTN were investigated on forty plants of the potato cv. Romano inoculated in a greenhouse in Serbia in 2012 and 2013. PVY isolates were collected from the potato growing region of Čačak and identified by ELISA and RT-PCR methods. The sequence of the Serbian isolate 3D (Acc. No. KJ946936 showed 100% match with seven PVY isolates deposited in GenBank and described as NTN. A significant difference was detected between PVYNTN symptoms exibited on leaves of the cv. Romano under primary and secondary infections. The findings are significant because they are based on symptoms observed, so that it is clear that there are two distinct types of infection: primary and secondary. Symptoms of primary and secondary infection were the same on potato tubers and had the form of necrotic rings.

  18. Slurry sampling in serum blood for mercury determination by CV-AFS

    International Nuclear Information System (INIS)

    Aranda, Pedro R.; Gil, Raul A.; Moyano, Susana; De Vito, Irma; Martinez, Luis D.

    2009-01-01

    The heavy metal mercury (Hg) is a neurotoxin known to have a serious health impact even at relatively low concentrations. A slurry method was developed for the sensitive and precise determination of mercury in human serum blood samples by cold vapor generation coupled to atomic fluorescence spectrometry (CV-AFS). All variables related to the slurry formation were studied. The optimal hydrochloric concentration and tin(II) chloride concentration for CV generation were evaluated. Calibration within the range 0.1-10 μg L -1 Hg was performed with the standard addition method, and compared with an external calibration. Additionally, the reliability of the results obtained was evaluated by analyzing mercury in the same samples, but submitted to microwave-assisted digestion method. The limit of detection was calculated as 25 ng L -1 and the relative standard deviation was 3.9% at levels around of 0.4 μg L -1 Hg

  19. Le « CV multilingue automatisé »

    OpenAIRE

    Terrier, Linda; Vaillant Sirdey, Christine; Arino, Mathilde

    2014-01-01

    De par leur mission d’insertion professionnelle, les IUT ont depuis longtemps inscrit dans leurs programmes pédagogiques nationaux l’élaboration du curriculum vitae en langue(s) étrangère(s). La politique de mobilité internationale encourage aujourd’hui toutes les formations universitaires du secteur LANSAD à intégrer la création d’un CV dans leur formation en langue.La rédaction d’un CV, déjà complexe en langue maternelle, réclame pour d’autres langues la maîtrise de savoir-faire spécifiques...

  20. Sim4CV: A Photo-Realistic Simulator for Computer Vision Applications

    KAUST Repository

    Müller, Matthias

    2018-03-24

    We present a photo-realistic training and evaluation simulator (Sim4CV) (http://www.sim4cv.org) with extensive applications across various fields of computer vision. Built on top of the Unreal Engine, the simulator integrates full featured physics based cars, unmanned aerial vehicles (UAVs), and animated human actors in diverse urban and suburban 3D environments. We demonstrate the versatility of the simulator with two case studies: autonomous UAV-based tracking of moving objects and autonomous driving using supervised learning. The simulator fully integrates both several state-of-the-art tracking algorithms with a benchmark evaluation tool and a deep neural network architecture for training vehicles to drive autonomously. It generates synthetic photo-realistic datasets with automatic ground truth annotations to easily extend existing real-world datasets and provides extensive synthetic data variety through its ability to reconfigure synthetic worlds on the fly using an automatic world generation tool.

  1. Maintaining Growth and Sustainable Strategy in Brown Sugar Business, and the Investment Financing Alternative Decision (Case Study: CV. Delovry Sukses Gemilang)

    OpenAIRE

    Ariyani, Laurentia Nindita; Siahaan, Uke MMP

    2013-01-01

    CV. Delovry Sukses Gemilang (CV. DSG) is a brown sugar supplier from manufacturers in Maron Village, Blitar, to the warehouse of distributors which is located in Tambun, Bekasi. In doing the business, CV. DSG provides the working capital to the collectors in Blitar to produce and pack the brown sugar. Fluctuating commodity prices of sugar cane leads CV. DSG to be difficult to continually maintain the business and shipping costs which is a way further from Blitar to Bekasi. These issues lead C...

  2. Crimson Viper, Phase IV: Field Experimentation Venue Report and CV14 Combined Report

    Science.gov (United States)

    2014-09-01

    battery sources. The system consists of a master node and other nodes used to create a wireless dark network. The wireless mesh nodes are self...create a wireless dark network. The wireless mesh nodes are self-configuring and self-healing. During CV14 Phase IV, separation of nodes averaged...the southern tip of the province, close to the tourism center Pattaya. The Sattahip Naval Base is the largest base of the Royal Thai Navy and is home

  3. Qualitative analysis of laser cutting of CV joints for automobile industry

    Science.gov (United States)

    Aboites, Vicente; Ramirez, Roberto; Rayas, Juan

    2005-02-01

    The optimization of an automatic laser cutting system is reported. This CO2 laser system assisted by an O2 gas jet is used in the cutting of Constant Velocity (CV) joint for the automotive industry. The experimental parameters varied in order to obtain cuts with low roughness were the laser power, cutting speed and oxygen pressure. A mathematical model is presented which explains many of the features of the qualitative optimization realized.

  4. Qualitative analysis of laser cutting of CV joints for the automobile industry

    Science.gov (United States)

    Aboites, V.; Ramírez, R.; Rayas, J.

    2006-02-01

    The optimization of an automatic laser cutting system is reported. This CO II laser system assisted by an O II gas jet is used in the cutting of Constant Velocity (CV) joint for the automotive industry. The experimental parameters varied in order to obtain cuts with low roughness were the laser power, cutting speed and oxygen pressure. A mathematical model is presented which explains many of the features of the qualitative optimization realized.

  5. Analisis Dan Rekayasa Supplier Relationship Management System Pada CV. Softcom Medan

    OpenAIRE

    Sukiman

    2012-01-01

    CV. SOFTCOM is a business entity engages in the computer sales and repair services. At the beginning of its establishment, the company did not see the importance of specialized brand in selling its product. The background of this study was the phenomenon in which many suppliers and different brands of the products found in the market that the company found it difficult to serve its customers claiming the damage of the sold products, the time of product delivered by the suppliers was frequentl...

  6. Auditory extinction and dichotic listening cv task in cerebral infarction preliminary report

    Directory of Open Access Journals (Sweden)

    Mauro Muszkat

    1990-06-01

    Full Text Available Six stroke patients were studied using a dichotic listening¹ CV task, 4 with left hemisphere infarction, 2 with right hemisphere infarction. It was observed a «lesion--effect», a shift of hemisphere prevalence to the side opposite a brain lesion. The authors suggest that the lesion-effect can be explained by the auditory extinction phenomenon at the linguistic level.

  7. Implementasi JSON Parsing Pada Aplikasi Mobile E-commerce Studi Kasus : CV V3 Tekno Indonesia

    OpenAIRE

    Destian Wijaya, Bhakti; E.M.A, Fenty; Fiade, Andrew

    2015-01-01

    Sistem operasi Android saat ini merupakan salah satu dari sekian banyak sistem operasi padasmartphone yang sedang mengalami pertumbuhan pesat di dunia, khususnya di Indonesia. CV VitigaTekno Indonesia bergerak di bidang pemasaran gadget membutuhkan media marketing yang dapatdiakses secara online selain website yaitu melalui smartphone. Oleh karena itu penelitian ini berfokuspada bagaimana membuat aplikasi mobile e-commerce pada smartphone Android, dengan caramengambil data yang berasal dari w...

  8. IV and CV curves for irradiated prototype BTeV silicon pixel sensors

    International Nuclear Information System (INIS)

    Coluccia, Maria R.

    2002-01-01

    The authors present IV and CV curves for irradiated prototype n + /n/p + silicon pixel sensors, intended for use in the BTeV experiment at Fermilab. They tested pixel sensors from various vendors and with two pixel isolation layouts: p-stop and p-spray. Results are based on exposure with 200 MeV protons up to 6 x 10 14 protons/cm 2

  9. Real-time detecting and tracking ball with OpenCV and Kinect

    Science.gov (United States)

    Osiecki, Tomasz; Jankowski, Stanislaw

    2016-09-01

    This paper presents a way to detect and track ball with using the OpenCV and Kinect. Object and people recognition, tracking are more and more popular topics nowadays. Described solution makes it possible to detect ball based on the range, which is set by the user and capture information about ball position in three dimensions. It can be store in the computer and use for example to display trajectory of the ball.

  10. A real-time camera calibration system based on OpenCV

    Science.gov (United States)

    Zhang, Hui; Wang, Hua; Guo, Huinan; Ren, Long; Zhou, Zuofeng

    2015-07-01

    Camera calibration is one of the essential steps in the computer vision research. This paper describes a real-time OpenCV based camera calibration system, and developed and implemented in the VS2008 environment. Experimental results prove that the system to achieve a simple and fast camera calibration, compared with MATLAB, higher precision and does not need manual intervention, and can be widely used in various computer vision system.

  11. A Geometric Correction Method of Plane Image Based on OpenCV

    Directory of Open Access Journals (Sweden)

    Li Xiaopeng

    2014-02-01

    Full Text Available Using OpenCV, a geometric correction method of plane image from single grid image in a state of unknown camera position is presented. The method can remove the perspective and lens distortions from an image. The method is simple and easy to implement, and the efficiency is high. Experiments indicate that this method has high precision, and can be used in some domains such as plane measurement.

  12. Phytoremediation of 4,4'-thiodiphenol (TDP) and other bisphenol derivatives by Portulaca oleracea cv.

    Science.gov (United States)

    Okuhata, Hiroshi; Ninagawa, Masahiko; Takemoto, Naomichi; Ji, Hezhe; Miyasaka, Hitoshi; Iwamoto, Ai; Nagae, Masaki; Ishibashi, Yasuhiro; Arizono, Koji

    2013-01-01

    4,4'-Thiodiphenol (TDP) is a bisphenol derivative, and there has been no report on TDP removal by any plants or pure bacterial cultures. The removal of TDP by Portulaca oleracea cv., a floricultural herbal plant, was examined with a hydroculture system, and 97% of TDP was removed after 4 days culture. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  13. Analisis Potensi Kecelakaan Kerja Pada CV. Automotive Workshop Dengan Metode Failure Mode and Effect Analysis

    OpenAIRE

    Syauqi, Qiqi Azwani; Susanty, Aries

    2016-01-01

    [Potential Analysis of Work Accidents at CV. Automotive Workshop using Failure Mode and Effect Analysis Method] Nowadays the global automotive industry, especially in developing countries has increased along with the increasing number of internet users and mobile penetration, the GDP rate increase of the developing countries and the growth of middle class-society, which makes the car sales in these countries increased anually. According to Carmudi, Semarang was the second-highest of the car l...

  14. CV Raman

    Indian Academy of Sciences (India)

    formatted to take advantage of the changes in publishing methods in the past thirty ..... This work would not have been possible without the support and en- couragement of ..... in which Raman made his decision, have a deeper significance than .... Light in Water and the Colour of the Sea within a month of his return to India ...

  15. Exploring the SDSS Data Set with Linked Scatter Plots. I. EMP, CEMP, and CV Stars

    Energy Technology Data Exchange (ETDEWEB)

    Carbon, Duane F.; Henze, Christopher; Nelson, Bron C., E-mail: Duane.F.Carbon@nasa.gov [NASA Ames Research Center, NASA Advanced Supercomputing Facility, Moffett Field, CA, 94035-1000 (United States)

    2017-02-01

    We present the results of a search for extremely metal-poor (EMP), carbon-enhanced metal-poor (CEMP), and cataclysmic variable (CV) stars using a new exploration tool based on linked scatter plots (LSPs). Our approach is especially designed to work with very large spectrum data sets such as the SDSS, LAMOST, RAVE, and Gaia data sets, and it can be applied to stellar, galaxy, and quasar spectra. As a demonstration, we conduct our search using the SDSS DR10 data set. We first created a 3326-dimensional phase space containing nearly 2 billion measures of the strengths of over 1600 spectral features in 569,738 SDSS stars. These measures capture essentially all the stellar atomic and molecular species visible at the resolution of SDSS spectra. We show how LSPs can be used to quickly isolate and examine interesting portions of this phase space. To illustrate, we use LSPs coupled with cuts in selected portions of phase space to extract EMP stars, CEMP stars, and CV stars. We present identifications for 59 previously unrecognized candidate EMP stars and 11 previously unrecognized candidate CEMP stars. We also call attention to 2 candidate He ii emission CV stars found by the LSP approach that have not yet been discussed in the literature.

  16. Analisis Pengaruh Kemampuan, Usaha dan Dukungan Perusahaan terhadap Kinerja Karyawan pada CV Sandang Gloria Konveksindo

    Directory of Open Access Journals (Sweden)

    Jerry Logahan

    2012-05-01

    Full Text Available Clothing Konveksindo CV Gloria is a trading company engaged in the sale of products and clothing items. Therefore, the performance of employees is very important in achieving that goal. The purpose of this study was to analyze the influence of ability, effort, and support the company towards the employee's performance CV Gloria Konveksindo Clothing. The method of analysis used in this study is descriptive, Pearson Regression, and Multiple Regression. Data obtained from the appraisal of employee performance by filling in the questionnaire that has been provided by using a Likert scale that is useful to know the degree of disagreement and agreement existing employees to the question on the questionnaire. The results achieved in this study were the ability of employees to work have an influence for 28.8% of employee performance, employee efforts in working to have the effect of 50.6% on employee performance, corporate support for work processes have the effect of 47.7% the performance of employees, while the ability of employees, employee efforts, and support the company has influence for 66.3% of the employee's performance CV Gloria Konveksindo Clothing. With this capability expected of employees, employee efforts, and support the company serve as the main factor to improve employee performance.

  17. MANAJEMEN RANTAI PASOKAN JAGUNG ASALAN PADA CV AMIN DI LAMPUNG TENGAH

    Directory of Open Access Journals (Sweden)

    Rahmad Budiono

    2016-10-01

    Full Text Available Salah satu komoditi palawija yang memiliki peranan yang penting di Indonesia adalah jagung, karena merupakan sumber protein dan kalori yang sangat dibutuhkan oleh ayam peternak. Pengiriman yang belum tepat waktu merupakan penyebab belum efisiennya kinerja rantai pasokan jagung. Oleh karena itu penelitian ini bertujuan untuk (1 mengidentifikasi dan mengkaji pengelolaan rantai pasokan jagung pada CV. AMIN, (2 menganalisis kinerja rantai pasokan jagung dalam hal efisiensi dan pelaksanaan kemitraan, dan (3 menganalisis alternatif kebijakan pengembangan manajemen rantai pasokan berdasarkan hasil evaluasi rantai pasokan.Penelitian akan dilakukan di CV. AMIN, Jl. Raya Merapi, Lampung Tengah dan petani mitra yang berada di kabupaten Nganjuk. Penelitian mengenai manajemen rantai pasokan Jagung tersebut dilakukan pada bulan Desember 2012 hingga Januari 2013. Pengumpulan data dilakukan dengan observasi. Responden dalam penelitian ini adalah petani jagung yang berada di Nganjuk, Pengepul, pihak CV. AMIN, dan Gudang Ternak. Penelitian dilakukan dengan metode analisis deskriptif kerangka Food Supply Chain Networking (FSCN, analisis tataniaga, dan analisis deskriptif dengan menggunakan kesesuaian atribut.

  18. Programación de Aplicaciones OpenCV sobre Sistemas Heterogéneos SoC-FPGA

    OpenAIRE

    Sanchis Cases, Francisco José

    2014-01-01

    OpenCV es una biblioteca de primitivas de procesado de imagen que permite crear algoritmos de Visión por Computador de última generación. OpenCV fue desarrollado originalmente por Intel en 1999 para mostrar la capacidad de procesamiento de los micros de Intel, por lo que la mayoría de la biblioteca está optimizada para correr en estos micros, incluyendo las extensiones MMX y SSE. http://en.wikipedia.org/wiki/OpenCV. Actualmente es ampliamente utilizada tanto por la comunidad científica como p...

  19. Aminoethoxivinilglicina no controle do amadurecimento de frutos de caqui cv. Fuyu Aminoethoxyvinylglycine in the ripening control of persimmon fruits cv. Fuyu

    Directory of Open Access Journals (Sweden)

    Angela Fuentes Fagundes

    2006-04-01

    Full Text Available Objetivou-se avaliar o efeito de aminoethoxivinilglicina (AVG, aplicado na pós-colheita, no amadurecimento de frutos de caqui (Diospyros kaki L. cv. Fuyu, armazenados à temperatura de 0 ± 2 ºC. Os frutos foram imersos durante dois minutos em solução de AVG, na concentração de 0; 415; 830 e 1.200 g ha-1 e dissolvidos em água destilada e adição de espalhante adesivo (óleo vegetal a 0,02% (v/v, secos à temperatura ambiente no barracão e armazenados em câmara fria a 0 ± 2 ºC e 95±2 % UR, e avaliados aos 32 e 52 dias com relação à firmeza, sólidos solúveis, pH da polpa, acidez titulável e injúria por frio. O AVG mostrou-se promissor no uso pós-colheita em caqui, onde os frutos tratados conservaram índices de firmeza linear em função da dose e teores de AT, SS e pH aceitáveis para o 'Fuyu'. Porém os frutos apresentaram translucidez, característica de injúria por frio, indicando a necessidade de novos estudos para se compreender a fisiologia pós-colheita deste fruto.An experiment was carried out to analyze the effect of the application of Aminoethoxyvinylglycine (AVG in post harvest application in persimmon fruits (Diospyros kaki L. cv. Fuyu stored at a temperature of 0 ± 2ºC. The fruits were immersed for two minutes into an AVG solution at a concentration of 0; 415; 830; 1200 g ha-1 and dissolved in distillated water. Then it was added adhesive spreader (vegetable oil 0.02% (v/v, dried at room temperature and stored at 0 ± 2 ºC and 95±2 % humidity. The treatments were evaluated on the 32nd and 52nd days to check the firmness, soluble solids, pH of the pulp, tritable acidity and chilling injury. The AVG may be promising in post harvest use with persimmon fruits, where treated fruits preserved linear levels of firmness in function of the doses and TA, SS and pH levels are acceptable for cv. Fuyu. However, fruits showed translucency, which are characteristics of chilling injury, indicating that new studies are

  20. BACTERIAL CONTAMINATION CONTROL IN BANANA EXPLANTS (Musa AAA cv. CAIPIRA) CONTROLE DE BACTÉRIAS CONTAMINANTES EM EXPLANTES DE BANANEIRA (Musa AAA cv. CAIPIRA)

    OpenAIRE

    Juliana Domingues Lima; Wilson da Silva Moraes

    2007-01-01

    Esse trabalho teve por objetivo testar métodos de controle de contaminação bacteriana no processo de multiplicação in vitro de bananeira (Musa AAA cv. Caipira), utilizando-se hipoclorito de sódio (NaOCl), antibiótico rifampicina e suas combinações. Não houve oxidação excessiva dos explantes após a imersão em NaOCl ou rifampicina. O melhor tratamento para explantes recém isolados foi imersão em NaOCl a 1% (v/v), dura...

  1. WNT Inhibitory Activity of Malus Pumila miller cv Annurca and Malus domestica cv Limoncella Apple Extracts on Human Colon-Rectal Cells Carrying Familial Adenomatous Polyposis Mutations.

    Science.gov (United States)

    Riccio, Gennaro; Maisto, Maria; Bottone, Sara; Badolati, Nadia; Rossi, Giovanni Battista; Tenore, Gian Carlo; Stornaiuolo, Mariano; Novellino, Ettore

    2017-11-18

    Inhibitors of the Wingless-related Integration site (WNT)/β-catenin pathway have recently been under consideration as potential chemopreventive agents against Familial Adenomatous Polyposis (FAP). This autosomal-dominant syndrome is caused by germline mutations in the gene coding for the protein APC and leads to hyperactivation of the WNT/β-catenin signaling pathway, uncontrolled intestinal cell proliferation and formation of adenocarcinomas. The aim of the present work was to: (i) test, on in vitro cultures of cells carrying FAP mutations and on ex vivo biopsies of FAP patients, the WNT inhibitory activity of extracts from two common southern Italian apples, Malus pumila Miller cv. 'Annurca' and Malus domestica cv 'Limoncella'; (ii) identify the mechanisms underpinning their activities and; (iii) evaluate their potency upon gastrointestinal digestion. We here show that both Annurca and Limoncella apple extracts act as WNT inhibitors, mostly thanks to their polyphenolic contents. They inhibit the pathway in colon cells carrying FAP mutations with active dilutions falling in ranges close to consumer-relevant concentrations. Food-grade manufacturing of apple extracts increases their WNT inhibitory activity as result of the conversion of quercetin glycosides into the aglycone quercetin, a potent WNT inhibitor absent in the fresh fruit extract. However, in vitro simulated gastrointestinal digestion severely affected WNT inhibitory activity of apple extracts, as result of a loss of polyphenols. In conclusion, our results show that apple extracts inhibit the WNT pathway in colon cells carrying FAP mutations and represent a potential nutraceutical alternative for the treatment of this pathology. Enteric coating is advisable to preserve the activity of the extracts in the colon-rectal section of the digestive tract.

  2. WNT Inhibitory Activity of Malus Pumila miller cv Annurca and Malus domestica cv Limoncella Apple Extracts on Human Colon-Rectal Cells Carrying Familial Adenomatous Polyposis Mutations

    Directory of Open Access Journals (Sweden)

    Gennaro Riccio

    2017-11-01

    Full Text Available Inhibitors of the Wingless-related Integration site (WNT/β-catenin pathway have recently been under consideration as potential chemopreventive agents against Familial Adenomatous Polyposis (FAP. This autosomal-dominant syndrome is caused by germline mutations in the gene coding for the protein APC and leads to hyperactivation of the WNT/β-catenin signaling pathway, uncontrolled intestinal cell proliferation and formation of adenocarcinomas. The aim of the present work was to: (i test, on in vitro cultures of cells carrying FAP mutations and on ex vivo biopsies of FAP patients, the WNT inhibitory activity of extracts from two common southern Italian apples, Malus pumila Miller cv. ‘Annurca’ and Malus domestica cv ‘Limoncella’; (ii identify the mechanisms underpinning their activities and; (iii evaluate their potency upon gastrointestinal digestion. We here show that both Annurca and Limoncella apple extracts act as WNT inhibitors, mostly thanks to their polyphenolic contents. They inhibit the pathway in colon cells carrying FAP mutations with active dilutions falling in ranges close to consumer-relevant concentrations. Food-grade manufacturing of apple extracts increases their WNT inhibitory activity as result of the conversion of quercetin glycosides into the aglycone quercetin, a potent WNT inhibitor absent in the fresh fruit extract. However, in vitro simulated gastrointestinal digestion severely affected WNT inhibitory activity of apple extracts, as result of a loss of polyphenols. In conclusion, our results show that apple extracts inhibit the WNT pathway in colon cells carrying FAP mutations and represent a potential nutraceutical alternative for the treatment of this pathology. Enteric coating is advisable to preserve the activity of the extracts in the colon-rectal section of the digestive tract.

  3. A combined SEM, CV and EIS study of multi-layered porous ceramic reactors for flue gas purification

    DEFF Research Database (Denmark)

    He, Zeming; Andersen, Kjeld Bøhm; Nygaard, Frederik Berg

    2013-01-01

    The effect of sintering temperature of 12-layered porous ceramic reactors (comprising 5 cells) was studied using scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The difference in microstructures of the reactors was evaluated by SEM...

  4. Automated and connected vehicle (AV/CV) test bed to improve transit, bicycle, and pedestrian safety : technical report.

    Science.gov (United States)

    2017-02-01

    Crashes involving transit vehicles, bicyclists, and pedestrians are a concern in Texas, especially in urban areas. This research explored the potential of automated and connected vehicle (AV/CV) technology to reduce or eliminate these crashes. The pr...

  5. Defective secretion of mucilage is the cellular basis for agravitropism in primary roots of Zea mays cv. Ageotropic

    Science.gov (United States)

    Miller, I.; Moore, R.

    1990-01-01

    Root caps of primary, secondary, and seminal roots of Z. mays cv. Kys secrete large amounts of mucilage and are in close contact with the root all along the root apex. These roots are strongly graviresponsive. Secondary and seminal roots of Z. mays cv. Ageotropic are also strongly graviresponsive. Similarly, their caps secrete mucilage and closely appress the root all along the root apex. However, primary roots of Z. mays cv. Ageotropic are non-responsive to gravity. Their caps secrete negligible amounts of mucilage and contact the root only at the extreme apex of the root along the calyptrogen. These roots become graviresponsive when their tips are coated with mucilage or mucilage-like materials. Peripheral cells of root caps of roots of Z. mays cv. Kys contain many dictyosomes associated with vesicles that migrate to and fuse with the plasmalemma. Root-cap cells of secondary and seminal (i.e. graviresponsive) roots of Z. mays cv. Ageotropic are similar to those of primary roots of Z. mays cv. Kys. However, root-cap cells of primary (i.e. non-graviresponsive) roots of Z. mays cv. Ageotropic have distended dictyosomal cisternae filled with an electron-dense, granular material. Large vesicles full of this material populate the cells and apparently do not fuse with the plasmalemma. Taken together, these results suggest that non-graviresponsiveness of primary roots of Z. mays cv. Ageotropic results from the lack of apoplastic continuity between the root and the periphery of the root cap. This is a result of negligible secretion of mucilage by cells along the edge of the root cap which, in turn, appears to be due to the malfunctioning of dictyosomes in these cells.

  6. Kedudukan Para Pihak Dalam Perjanjian Waralaba Studi : Perjanjian Waralaba Antara PT. Indomarco Prismatama Dengan CV. E. Makmur

    OpenAIRE

    Putra, M. S. Feroni

    2011-01-01

    The rapid franchising business development occurs because the franchising system in general has more probable success compared to the self-performed business with a new trade mark, yet this franchising business agreement of Indomaret between PT. Indomarco Prismatama and CV. E. Makmur. The research question to be answered in this study were that were the rights what were the constraints faced by PT. Indomarco Prismatama and CV. E. Makmur in this agreement, and how did PT. Indomarco Prismatama ...

  7. ANALISIS KUALITAS KEHIDUPAN KERJA, KINERJA, DAN KEPUASAN KERJA PADA CV DUTA SENENAN JEPARA

    Directory of Open Access Journals (Sweden)

    Noor Arifin

    2012-04-01

    Full Text Available Abstract: Analysis of Work Quality, Performance, and Job Satisfaction in CV. Duta Senenan Jepara. This study aims to analyze the effect of the quality work life of employees to their performance, analyze the effect of the quality of work life to the job satisfaction, and analyze the effect of the job satisfaction to employee performance. Variables used in this study are: quality of work Life developed by Wayne Cascio 1992; the performance of employees, developed by Elmuti and Kathawala, 1997; and variables Job Satisfaction, provided by Robbin, 1996 and Wexley et al, 1992. The sample of this study consists of 65 employees. The data Analysis were performed using structural equation modeling with partial least square approach. The result suggests that the quality of work life affects the performance; the satisfaction affects the employee performance; and the quality of working life has no effect on employee satisfaction.   Keywords :  quality of work life, on job satisfaction, employee performance   Abstrak: Analisis Kualitas Kehidupan, Kinerja, dan Kepuasan Kerja pada CV. Duta Senenan Jepara. Penelitian ini bertujuan untuk menganalisis pengaruh kualitas kehidupan kerja terhadap kinerja karyawan, menganalisis pengaruh kualitas kehidupan kerja terhadap kepuasan kerja, dan menganalisis pengaruh kepuasan kerja terhadap kinerja karyawan. Variabel yang digunakan dalam penelitian ini adalah: Kualitas Kehidupan Kerja, dari Cascio Wayne 1992. kemudian kinerja karyawan, dari Elmuti dan Kathawala, 1997, dan Kepuasan Kerja, yang dikembangkan oleh Robbin, 1996 serta Wexley et.al., 1992. Penelitian ini mengambil sampel 65 karyawan dari CV DUTA Senenan Jepara. Teknik analisis yang digunakan adalah Structural Equation Modeling (SEM dengan pendekatan Partial Least Square (PLS. Penelitian ini menyimpulkan bahwa kualitas kehidupan kerja sangat berpengaruh terhadap kinerjanya; kepuasan berpengaruh terhadap kinerja karyawan dan kualitas kehidupan kerja tidak

  8. IMPLEMENTASI SIX SIGMA UNTUK PENINGKATAN KUALITAS SANDAL DI CV. SANCU CREATIVE INDONESIA

    Directory of Open Access Journals (Sweden)

    Sonny Koeswara

    2013-10-01

    Full Text Available Six Sigma adalah metodologi yang terstruktur untuk memperbaiki proses yang difokuskan pada usaha mengurangi variasi pada proses sekaligus mengurangi defect pada produk dengan menggunakan pendekatan statistik dan Problem solving tools secara intensif. Tujuan dari metode Six Sigma ini adalah untuk mendapatkan zero defect dengan menjalankan 5 tahapan yaitu : Define, Measure, Analyze, Improve ,dan Control (DMAIC. Tulisan ini bertujuan untuk menerapkan metode Six Sigma di Cv. Sancu Creative Indonesia yang merupakan badan usaha yang memproduksi sandal karakter. Masalah yang terjadi adalah adanya defect sol sandal mudah mengelupas yang berakibat pada kualitas sandal dan salah satu penghambat visi dan misi perusahaan. Penelitian ini dibagi dalam 5 tahap. Tahap pertama adalah Define, yang bertujuan untuk mengidentifikasi masalah yang terjadi yang berasal dari kebutuhan konsumen berdasarkan data DCA dan OQC defect di CV. SANCU. Tahap kedua adalah Measure yaitu mengukur kondisi level performance proses saat ini (Z-Level. Pada tahap ini dilakukan validasi sistem pengukuran  dengan  menghitung  Dpo,Dpmo,Yield  dan  Sigma  level.  Tahap  ketiga  adalah Analyze yaitu menentukan faktor-faktor penyebab terjadinya sol sandal mengelupas dan sekaligus menentukan vital faktor. Hasil dari pengujian menunjukkan bahwa vital faktor adalah waktu penempelan.Tahap keempat adalah improvement yaitu melakukan perbaikan dengan memberikan timer diarea lokasi penempelan. Control yaitu kegiatan melakukan pemantauan dari hasil perbaikan yang telah di implementasikan Kondisi   setelah   perbaikan   menghasilkan   perubahan   yang   signifikan   terhadap kapabilitas performance pada sandal, yaitu perubahan nilai sigma level setelah perbaikan 4.74s dari yang sebelum perbaikan adalah 4.26 s. Dari nilai tersebut dapat disimpulkan bahwa metode waktu penempelan dan kontrol pada performance sandal Cv. Sancu sudah membaik.

  9. Herpes simplex virus produces larger plaques when assayed on ultraviolet irradiated CV1 cells

    International Nuclear Information System (INIS)

    Coohill, T.P.; Babich, M.A.; Taylor, W.D.; Snipes, W.

    1980-01-01

    Plaque development for either untreated or UV treated irradiated Herpes simplex virus Type 1 was faster when assayed on UV irradiated CV1 cells. This Large Plaque Effect only occurred if a minimum delay of 12h between cell irradiation and viral inoculation was allowed. Shorter delays gave plaques that were smaller than controls (unirradiated virus-unirradiated cells). The effect was maximal for a 48-h delay and remained unchanged for delays as long as 84h. The effect was greatest for cell exposures of 10Jm -2 . (author)

  10. Development of high yielding mutants of Brassica campestris L. cv. Toria selection through gamma rays irradiation

    International Nuclear Information System (INIS)

    Javed, M.A.; Siddiqui, M.A.; Khan, M.K.R.; Khatri, A.; Khan, I.A.; Dahar, N.A.; Khanzada, M.H.; Khan, R.

    2003-01-01

    Homogeneous seeds of Brassica campestris L. cv. Toria selection were treated with different doses of gamma rays (750, 1000 and 1250 Gy) to induce genetic variability for the selection of new genotypes with improved agronomic traits. After passing through different stages of selection, two promising mutants were selected for further studies. Two selected mutants along with 5 other entries including parent variety were evaluated for yield and yield components in yield trials for two consecutive years. The mutant TS96-752 was significantly (P less than or equal to 0.05) superior to all other entries in grain yield but at par with FSD 86028-3

  11. In Vivo and in Vitro Micrografting of Pistachio, Pistacia vera L. cv. "Siirt"

    OpenAIRE

    ONAY, Ahmet; PİRİNÇ, Vedat; ADIYAMAN, Filiz; IŞIKALAN, Çiğdem; TİLKAT, Engin; BAŞARAN, Davut

    2014-01-01

    In this study, the success of in vivo and in vitro micrografts of pistachio (Pistacia vera L. cv. "Siirt") materials are presented. The only variable tested was age (1, 5, 10, and 30-year-old trees). Ten- to 12-day-old axenic seedlings germinated in vitro or seedlings (3 to 5 months-old) grown in pots in vivo were used as rootstocks. Shoot tips collected from the four age classes of mature trees of pistachio were the source of scions. Firm contact between the scion and roots...

  12. Study of the activation of the parts components of the CV-28 cyclotron

    International Nuclear Information System (INIS)

    Fajardo, P.W.

    1986-08-01

    The CV-17 cyclotron, isochronous, compact, of variable energy is an accelerator of charged particles and is applied in several situations such as: radioisotopes production, neutron production, irradiation damage analysis, activation analysis. During the production of the particle beams, the parts components of the interior of the cyclotron are irradiated and become radioactive. Due the fact of the cyclotron require maintenance, the knowledgement of the radionuclides present is of primordial importance of the view point of the radioprotection. Taking the excitation function of a nuclear reaction is observed that determined reaction may happen and produce a radionuclide. The radionuclides formed in the parts components by charged particles are presented. (V.R.B.)

  13. VARYING DEGREE OF GRAFTING COMPATIBILITY BETWEEN CV. CHARDONNAY, MERLOT AND DIFFERENT GRAPEVINE ROOTSTOCKS

    Directory of Open Access Journals (Sweden)

    Slavica TODIĆ

    2006-02-01

    Full Text Available Level of affi nity between grapevine rootstock and Vitis vinifera as scion, quality of reproductive materials and technological actions in grapevine rootstock production process determine success in grapevine rootstock production in large extent. Practical training showed that difference in level of compatibility between grapevine rootstock and grafted Vitis vinifera cultivars are existing. Direct effects of these differences are unequal yield of fi rst class grafted grapevine rootlings. In this paper, level of compatibility in nursery between clones of cv. Chardonnay BCL 75, VCR4 and cv. Merlot R18, MCL 519 and grapevine rootstocks Kober 5BB (Vitis berlandieri x V. riparia, SO4 (V. berlandieri x V. riparia and 41B (Chasselas x V.berlandieri were investigated. The trial was conducted in commercial grapevine nursery located in Velika Drenova, Serbia. As an index of compatibility, grade of high quality grapevine grafted rootlings, dry matter in mature shoots and root system development were used. Grafting was done by `tongue grafting` indoor technique. Stratifi cation was done in sand, on temperature of the stratifi cation material of 26-28oC, and humidity of around 90%. Grafted cuttings were waxed twice: before stratifi cation, and before planting in the nursery. Grafted rootlings were classed in two classes according to regulations of quality, (Yugoslav Offi cial Register, 26/79. Grafted rootlings that did not satisfi ed standard criteria were discarded. Both clones of cv. Chardonnay gave the highest percentage of I class grafted rootlings on grapevine rootstock 41B: clone BCL 75 – 60% and clone VCR4 – 61%. In the same combination, those grapevine grafted rootlings had the highest weight of the root system. Lower percentage of obtained I class grafted rootlings was established on rootstock Kober 5BB, while statistically signifi cantly lower yields were obtained on grapevine rootstock SO4: clone BCL75 – 43% and clone VCR4 – 48%. Dry

  14. Induction of chlorophyll chimeras and chlorophyll mutations in mungbean (Vigna radiata) cv. T44

    International Nuclear Information System (INIS)

    Singh, V.P.; Yadav, R.D.S.

    1993-01-01

    Uniform and healthy seeds of mungbean (Vigna radiata) cv. T44 were exposed to varying doses of gamma rays, ethyl methane sulphonate (EMS) and combination treatment of gamma rays with EMS. The data were recorded for seed germination, plant survival, frequency and spectrum of chlorophyll chimeras in M 1 and chlorophyll mutations in M 2 generation. Among all, the combination treatments were found most effective for inducing chlorophyll chimeras and chlorophyll mutations than the gamma rays or EMS alone. Of the mutants under reference, the albino, xantha and chlorina showed monogenic recessive while viridis exhibited digenic recessive inheritance. (author). 8 refs., 2 tabs

  15. Influence of gamma radiation on carbohydrates metabolism of ripening papaya (Carica papaya L. cv. Solo)

    International Nuclear Information System (INIS)

    Gomez, M.L.P.A.; Lajolo, F.M.; Cordenunsi, B.R.

    1999-01-01

    Food irradiation is one of the most promising treatments that can be utilized for fruits disinfestation and extension of shelf life. The authors studied the influence of 0,5 kGy of Gamma irradiation on the soluble carbohydrates composition of papaya (Carica papaya L. cv. Solo) fruit, and on sucrose metabolizing enzymes: sucrose synthase (SS), sucrose-phosphate synthase, acid and neutral invertases activities, during ripening. The results demonstrated that ethylene production, total soluble sugars, sucrose content, and sucrose-phosphate synthase and invertases activities were affected by irradiation, but not respiration, glucose and fructose content, and SS activity. (author)

  16. INDIVIDUAL PACKAGING OF MANGOS CV. TOMMY ATKINS IN PLASTIC FILM: EFFECT ON SHELF LIFE

    OpenAIRE

    YAMASHITA, FÁBIO; TONZAR, ANAMARIA CALDO; FERNANDES, JOICELENA GEORGETTI; MORIYA, SUELY; BENASSI, MARTA DE TOLEDO

    2001-01-01

    Estudou-se o efeito da embalagem de policloreto de vinila (PVC) sobre a vida de prateleira de mangas cv. Tommy Atkins armazenadas sob refrigeração. Mangas no estádio de maturidade fisiológica, com casca verde ou levemente avermelhada, foram embaladas individualmente, com filme de 10mm de espessura, e armazenadas por 28 dias a 12ºC (80-90% UR). Frutos sem embalagem serviram de controle. Durante o período de armazenagem, foram feitas avaliações sensoriais utilizando o método de escala hedônica ...

  17. 123 I production using CV-28 cyclotron from IPEN-CNEN/SP

    International Nuclear Information System (INIS)

    Mestnik, S.A.C.; Mengatti, J.; Nieto, W.; Yanagawa, S.I.; Sumiya, L.C.A.; Silva, C.P.G.; Osso Junior, J.A.

    1992-01-01

    The main conditions for iodine 123 production by 124 Te (p,2 n) 123 I reaction were presented, using the cyclotron CV-28 at IPEN-CNEN/SP, with protons of E max = 24 MeV. Two types of targets (Te O 2 and Te O 2 + 2% Al 2 O 3 ) and the influence of Al 2 O 3 in iodine release were studied. After the selection, the 124 Te O 2 (96,2%) target, was melted in platinum support and irradiated with proton current until 12 mu A. The separation of 123 I was made by dry distillation, using induction furnace and O 2 atmosphere. (C.G.C.)

  18. PERDAS QUALITATIVAS DE MAÇÃS CV. GALA EM ARMAZENAMENTO REFRIGERADO

    OpenAIRE

    BENDER, RENAR JOÃO; LUNARDI, ROSÂNGELA

    2001-01-01

    O presente trabalho foi desenvolvido com o objetivo de dimensionar as perdas de qualidade de maçãs cv. Gala durante o armazenamento refrigerado. Para determinar estas perdas, foi feito um acompanhamento durante três anos consecutivos, com frutos de três tamanhos: calibre em torno de 100 frutos/caixa de 18kg, calibre 130 e calibre acima de 200. Quinzenalmente, durante os primeiros 90 dias de armazenagem no primeiro ano, 144 dias no segundo ano e 211 dias no terceiro ano, amostras de 20 a 30 ma...

  19. Crecimiento en clavel estándar cv. Nelson, en suelo y en sustratos Crescimento de cravo estandar cv. Nelson, em solo e em substratos Growth of standard carnation cv. Nelson, in soil and substrates

    Directory of Open Access Journals (Sweden)

    Adriana Del Pilar Baracaldo Argüello

    2010-01-01

    Full Text Available El cultivo de clavel en la sabana de Bogotá ha sido importante, ya que representa en la actualidad el segundo lugar de exportación en flores de corte. Recientemente, su producción en sistema de cultivo en sustrato ha aumentado debido fundamentalmente a limitantes de tipo sanitario, por lo cual es importante el estudio del crecimiento de las plantas establecidas en este sistema de cultivo. El objetivo de este estudio fue evaluar el crecimiento del clavel estándar cv. Nelson establecido en sustratos y en suelo, a segundo pico de cosecha, para lo cual, en el SENA - Centro Multisectorial de Mosquera, plantas de clavel se sometieron a los siguientes tratamientos: 100% de cascarilla de arroz quemada; 65% cascarilla de arroz quemada - 35% fibra de coco; 35% cascarilla de arroz quemada - 65% fibra de coco y suelo. En muestreos continuos se evaluaron las variables número de hojas, longitud del tallo, diámetro de tallo, número de nudos y diámetro y longitud del botón floral y se ajustaron curvas de crecimiento. Las plantas cultivadas en el tratamiento suelo presentaron mayor número de tallos. En este tratamiento los tallos florales también presentaron un mayor número de nudos y de hojas; sin embargo, fueron más cortos. Así mismo, presentaron menor diámetro de tallo y menor longitud y diámetro del botón floral; características determinantes de la calidad. Por tanto, la producción de tallos exportables de grado "select" fue significativamente inferior en el tratamiento suelo, en comparación con los demás tratamientos.O cultivo de cravo no planalto de Bogotá tem sido importante, visto que representa, na atualidade, o segundo lugar nas exportações colombianas de flores de corte. Recentemente, sua produção em sistemas de cultivo em substrato tem aumentado em consequência de fatores sanitários. O objetivo deste estudo foi avaliar o desenvolvimento do cravo tipo estandar cv. Nelson, estabelecido em substratos e em solo, na segunda

  20. ORGANIC FERTILIZER AS PHOSPHORUS SUPPLIER FOR Brachiaria brizantha CV. MARANDÚ FERTILIZANTE ORGÂNICO COMO FONTE DE FÓSFORO NO CULTIVO INICIAL DE Brachiaria brizantha CV. MARANDÚ

    Directory of Open Access Journals (Sweden)

    Diego Henriques Santos

    2010-05-01

    Full Text Available

    Phosphorus is considered an essential element for plants, but it is found in low amounts in Brazilian soils, mainly in areas destined to pastures, and the application of organic matter contributes to the improvement of physical, chemical and biological soil attributes. The research had the objective of evaluating the application effects of the Bokashi organic compound on soil macro and micronutrients contents and leaves, as well as on Brachiaria brizantha cv. Marandú dry mass yield, evaluating the potential of the organic fertilizer as phosphorus source, in comparison with conventional chemical fertilizers. Different organic compound doses supplied the soil with 17 kg P2O5 ha-1, 34 kg P2O5 ha-1, 68 kg P2O5 ha-1, 136 kg P2O5 ha-1, and 204 kg P2O5 ha-1, comparing it with the conventional chemical fertilizer and the control. The results revealed that the organic fertilizer Bokashi can adequately replace the conventional chemical fertilizer of Brachiaria brizantha cv. Marandú, supplying the soil and plant with appropriate nutrients levels and maintaining the dry mass yield.

    KEY-WORDS: Organic matter; organic fertilizers; plants mineral nutrition; Bokashi

  1. Heterogeneous compute in computer vision: OpenCL in OpenCV

    Science.gov (United States)

    Gasparakis, Harris

    2014-02-01

    We explore the relevance of Heterogeneous System Architecture (HSA) in Computer Vision, both as a long term vision, and as a near term emerging reality via the recently ratified OpenCL 2.0 Khronos standard. After a brief review of OpenCL 1.2 and 2.0, including HSA features such as Shared Virtual Memory (SVM) and platform atomics, we identify what genres of Computer Vision workloads stand to benefit by leveraging those features, and we suggest a new mental framework that replaces GPU compute with hybrid HSA APU compute. As a case in point, we discuss, in some detail, popular object recognition algorithms (part-based models), emphasizing the interplay and concurrent collaboration between the GPU and CPU. We conclude by describing how OpenCL has been incorporated in OpenCV, a popular open source computer vision library, emphasizing recent work on the Transparent API, to appear in OpenCV 3.0, which unifies the native CPU and OpenCL execution paths under a single API, allowing the same code to execute either on CPU or on a OpenCL enabled device, without even recompiling.

  2. Quality characteristics of soybean pasted (Doenjang) manufactured with 2 soybean mutant lines derived from cv. baekwon

    International Nuclear Information System (INIS)

    Lee, Kyung Jun; Kang, Si Yong; Choi, Hong Il; Kim, Jin Baek

    2016-01-01

    In order to identification of the possibility of manufacturing soybean paste (doenjang) with soybean mutant lines induced from gamma-ray mutagenesis, this study was performed to investigate the quality characteristics of doenjang using two soybean mutant lines, Baekwon-1 (BW-1) and Baekwon-2 (BW-2) and their original cultivar (cv. Baekwon, BW) for 8 weeks. The BW and two mutant lines (BW-1 and BW-2) were showed higher content of amino type nitrogen than control (cv. Taegwang). The pH decreased and the titratable acidity increased all the samples during aging period. The lightness, redness and yellowness of doenjang were the lowest in BW. Total free sugar content of doenjang was the highest in control (10.43%) after 4 weeks and composed mainly fructose and glucose. The order of the free amino acid content was Glutamic acid>Leucine>Lysine>Phenylalanine>Aspartic acid in control, Glutamic acid>Leucine >Arginine>Lysine>Phenylalanine in BW, Glutamic acid>Lysine>Phenylalanine>Aspartic acid>Valine in BW-1 and Glutamic acid>Arginine>Lysine>Phenylalanine>Aspartic acid in BW-2, respectively. Our results showed that it is possible to increase the quality of doenjang using soybean mutant lines in manufacturing soybean paste

  3. Biosynthesized Silver Nanoparticles Used in Preservative Solutions for Chrysanthemum cv. Puma

    Directory of Open Access Journals (Sweden)

    Luis M. Carrillo-López

    2016-01-01

    Full Text Available The use of pulse solutions containing antimicrobials has been reported, but more research is necessary. To increase vase life and to study their effect on opening inflorescences, silver nanoparticles were used in vase solutions for cv. Puma Chrysanthemum stems. The nanoparticles were synthesized biologically using Chenopodium ambrosioides L. applied at concentrations of 0.01, 0.05, 0.1, 0.5, 1, and 5 mM and compared with a control. Treatments were replicated five times. The stems were cut to 50 cm and observed until the end of their vase life. Low concentrations of silver nanoparticles promoted inflorescence opening and leaf yellowing, while the control leaves remained green, but there was a lower degree of inflorescence opening. High concentrations of silver nanoparticles (0.5, 1, and 5 mM caused senescence due to low water uptake through the stems. Statistical differences in inflorescence opening and diameter, bacterial growth (CFU mL−1 in vase solutions, fresh weight, water uptake, and vase life were found among treatments. Longer vase life and less weight loss were observed in the stems exposed to low concentrations of silver nanoparticles. Low concentrations of silver nanoparticles promoted inflorescence opening and increased vase life of Chrysanthemum cv. Puma.

  4. Intestinal Permeability and Cellular Antioxidant Activity of Phenolic Compounds from Mango (Mangifera indica cv. Ataulfo Peels

    Directory of Open Access Journals (Sweden)

    Ramón Pacheco-Ordaz

    2018-02-01

    Full Text Available Mango (Mangifera indica cv. Ataulfo peel contains bound phenolics that may be released by alkaline or acid hydrolysis and may be converted into less complex molecules. Free phenolics from mango cv. Ataulfo peel were obtained using a methanolic extraction, and their cellular antioxidant activity (CAA and permeability were compared to those obtained for bound phenolics released by alkaline or acid hydrolysis. Gallic acid was found as a simple phenolic acid after alkaline hydrolysis along with mangiferin isomers and quercetin as aglycone and glycosides. Only gallic acid, ethyl gallate, mangiferin, and quercetin were identified in the acid fraction. The acid and alkaline fractions showed the highest CAA (60.5% and 51.5% when tested at 125 µg/mL. The value of the apparent permeability coefficient (Papp across the Caco-2/HT-29 monolayer of gallic acid from the alkaline fraction was higher (2.61 × 10−6 cm/s than in the other fractions and similar to that obtained when tested pure (2.48 × 10−6 cm/s. In conclusion, mango peels contain bound phenolic compounds that, after their release, have permeability similar to pure compounds and exert an important CAA. This finding can be applied in the development of nutraceuticals using this important by-product from the mango processing industry.

  5. Biochemical markers assisted screening of Fusarium wilt resistant Musa paradisiaca (L.) cv. puttabale micropropagated clones.

    Science.gov (United States)

    Venkatesh; Krishna, V; Kumar, K Girish; Pradeepa, K; Kumar, S R Santosh; Kumar, R Shashi

    2013-07-01

    An efficient protocol was standardized for screening of panama wilt resistant Musa paradisiaca cv. Puttabale clones, an endemic cultivar of Karnataka, India. The synergistic effect of 6-benzyleaminopurine (2 to 6 mg/L) and thidiazuron (0.1 to 0.5 mg/L) on MS medium provoked multiple shoot induction from the excised meristem. An average of 30.10 +/- 5.95 shoots was produced per propagule at 4 mg/L 6-benzyleaminopurine and 0.3 mg/L thidiazuron concentrations. Elongation of shoots observed on 5 mg/L BAP augmented medium with a mean length of 8.38 +/- 0.30 shoots per propagule. For screening of disease resistant clones, multiple shoot buds were mutated with 0.4% ethyl-methane-sulfonate and cultured on MS medium supplemented with Fusarium oxysporum f. sp. cubense (FOC) culture filtrate (5-15%). Two month old co-cultivated secondary hardened plants were used for screening of disease resistance against FOC by the determination of biochemical markers such as total phenol, phenylalanine ammonia lyase, oxidative enzymes like peroxidase, polyphenol oxidase, catalase and PR-proteins like chitinase, beta-1-3 glucanase activities. The mutated clones of M. paradisiaca cv. Puttabale cultured on FOC culture filtrate showed significant increase in the levels of biochemical markers as an indicative of acquiring disease resistant characteristics to FOC wilt.

  6. Intestinal Permeability and Cellular Antioxidant Activity of Phenolic Compounds from Mango (Mangifera indica cv. Ataulfo) Peels

    Science.gov (United States)

    Pacheco-Ordaz, Ramón; González-Aguilar, Gustavo A.

    2018-01-01

    Mango (Mangifera indica cv. Ataulfo) peel contains bound phenolics that may be released by alkaline or acid hydrolysis and may be converted into less complex molecules. Free phenolics from mango cv. Ataulfo peel were obtained using a methanolic extraction, and their cellular antioxidant activity (CAA) and permeability were compared to those obtained for bound phenolics released by alkaline or acid hydrolysis. Gallic acid was found as a simple phenolic acid after alkaline hydrolysis along with mangiferin isomers and quercetin as aglycone and glycosides. Only gallic acid, ethyl gallate, mangiferin, and quercetin were identified in the acid fraction. The acid and alkaline fractions showed the highest CAA (60.5% and 51.5%) when tested at 125 µg/mL. The value of the apparent permeability coefficient (Papp) across the Caco-2/HT-29 monolayer of gallic acid from the alkaline fraction was higher (2.61 × 10−6 cm/s) than in the other fractions and similar to that obtained when tested pure (2.48 × 10−6 cm/s). In conclusion, mango peels contain bound phenolic compounds that, after their release, have permeability similar to pure compounds and exert an important CAA. This finding can be applied in the development of nutraceuticals using this important by-product from the mango processing industry. PMID:29419800

  7. Business Strategy of CV Jaya Sampurna in Facing Soft Drink Distributor Competition in Bekasi

    Directory of Open Access Journals (Sweden)

    Seri Nurmala

    2015-11-01

    Full Text Available CV Jaya Sampurna is a soft drink distributor in Bekasi. Distributor company has a low profit margin, moreover the product sold is Fast Moving Consumers Goods with a very low profit margin (3.5%–5%. Therefore the company depends on a high volume of sales. Besides, there are many competitors in this industry, thus the business strategy is needed to improve the competitive advantage of the company. Given the conditions,this research was to identify the internal and the external factors, to identify the formulation of business strategy alternative, and to identify the recommendation of functional strategy for CV Jaya Sampurna. Research used descriptive method; and the type of research used was case study. Data were gathered from questionnaires and interview to three member of managers: Director, Operational Manager, and Finance Manager. Data wereanalyzed by using EFE, IFE, SWOT, IE, Grand Strategy Matrix and QSPM. The result of this research implies that the alternative strategy based on QSPM’s result was market penetration

  8. A FAST SEGMENTATION ALGORITHM FOR C-V MODEL BASED ON EXPONENTIAL IMAGE SEQUENCE GENERATION

    Directory of Open Access Journals (Sweden)

    J. Hu

    2017-09-01

    Full Text Available For the island coastline segmentation, a fast segmentation algorithm for C-V model method based on exponential image sequence generation is proposed in this paper. The exponential multi-scale C-V model with level set inheritance and boundary inheritance is developed. The main research contributions are as follows: 1 the problems of the "holes" and "gaps" are solved when extraction coastline through the small scale shrinkage, low-pass filtering and area sorting of region. 2 the initial value of SDF (Signal Distance Function and the level set are given by Otsu segmentation based on the difference of reflection SAR on land and sea, which are finely close to the coastline. 3 the computational complexity of continuous transition are successfully reduced between the different scales by the SDF and of level set inheritance. Experiment results show that the method accelerates the acquisition of initial level set formation, shortens the time of the extraction of coastline, at the same time, removes the non-coastline body part and improves the identification precision of the main body coastline, which automates the process of coastline segmentation.

  9. Information Hiding In Digital Video Using DCT, DWT and CvT

    Science.gov (United States)

    Abed Shukur, Wisam; Najah Abdullah, Wathiq; Kareem Qurban, Luheb

    2018-05-01

    The type of video that used in this proposed hiding a secret information technique is .AVI; the proposed technique of a data hiding to embed a secret information into video frames by using Discrete Cosine Transform (DCT), Discrete Wavelet Transform (DWT) and Curvelet Transform (CvT). An individual pixel consists of three color components (RGB), the secret information is embedded in Red (R) color channel. On the receiver side, the secret information is extracted from received video. After extracting secret information, robustness of proposed hiding a secret information technique is measured and obtained by computing the degradation of the extracted secret information by comparing it with the original secret information via calculating the Normalized cross Correlation (NC). The experiments shows the error ratio of the proposed technique is (8%) while accuracy ratio is (92%) when the Curvelet Transform (CvT) is used, but compared with Discrete Wavelet Transform (DWT) and Discrete Cosine Transform (DCT), the error rates are 11% and 14% respectively, while the accuracy ratios are (89%) and (86%) respectively. So, the experiments shows the Poisson noise gives better results than other types of noises, while the speckle noise gives worst results compared with other types of noises. The proposed technique has been established by using MATLAB R2016a programming language.

  10. Verbal cues effectively orient children's auditory attention in a CV-syllable dichotic listening paradigm.

    Science.gov (United States)

    Phélip, Marion; Donnot, Julien; Vauclair, Jacques

    2015-12-18

    In their groundbreaking work featuring verbal dichotic listening tasks, Mondor and Bryden showed that tone cues do not enhance children's attentional orienting, in contrast to adults. The magnitude of the children's right-ear advantage was not attenuated when their attention was directed to the left ear. Verbal cues did, however, appear to favour the orientation of attention at around 10 years, although stimulus-onset asynchronies (SOAs), which ranged between 450 and 750 ms, were not rigorously controlled. The aim of our study was therefore to investigate the role of both types of cues in a typical CV-syllable dichotic listening task administered to 8- to 10-year-olds, applying a protocol as similar as possible to that used by Mondor and Bryden, but controlling for SOA as well as for cued ear. Results confirmed that verbal cues are more effective than tone cues in orienting children's attention. However, in contrast to adults, no effect of SOA was observed. We discuss the relative difficulty young children have processing CV syllables, as well as the role of top-down processes in attentional orienting abilities.

  11. Testing Anchoring effect in CV Data from Dichotomous Choice with a Follow-up Questioning

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Young Cheol [Dae-Jin University, Pocheon (Korea)

    1998-09-01

    A questionnaire of dual bisected selection of CVM, which is an induced approach of intended payment, was suggested to overcome statistical inefficiency of a questionnaire of single bisected selection. In spite of several advantages of it, it is doubted that there would be an occurrence of anchoring effect, which is a psychological source of convenient starting point. Therefore, the general intended payment model, which can review the anchoring effect from CV questionnaire of dual bisected selection, was suggested and a mechanism that can review the anchoring effect from the model. This model is combining the dual variation model by Cameron and Quiggin (1994) with the results of bisected selective responses of a firstly presented particular amount as an explanatory variable of the second interior intended payment amount. If the sign of coefficient of the results of bisected selective responses of a firstly presented particular amount was negative and statistically significant, then it can be said that there is an anchoring effect. However, when there is uncertainty of occurrence of anchoring effect from the coefficient review, there is no need to worry about the anchoring effect if the average of estimated values of intended payment amount from two responses were different. As a result of applying this model and mechanism to CV materials on the improvement of water quality of the Han River, there is no need to worry about the anchoring effect. (author). 21 refs., 4 tabs.

  12. Obtaining of potato microtubers cv. ‘Andinita’ in Temporary Immersion Systems

    Directory of Open Access Journals (Sweden)

    Janet Igarza Castro

    2011-01-01

    Full Text Available The Instituto Nacional de Investigaciones Agrícolas (INIA, Venezuela, is producing potato seed by biotechnology in its National Seed Plan. The seeds needed are greater than the installed capacity. The acquisition of temporary immersion system (ITS enables developing research in the production of seed potatoes to ensure quality, efficiency and reduced production costs. The purchase of seeds will decrease and contribute to food security and sovereignty of the country. This work was aimed to obtain potato microtubers cv. ‘Andinita’ in SIT. In vitro plants propagated by organogenesis and SIT in 10 liters capacity were used. Explants (100 were inoculated per pot. After five weeks in multiplication a change of culture medium was carried out to induce tuberization. Three immersion frequencies were tested. Plant height was measured and the number of microtubers and fresh dough was quantified. Potato microtubers cv. ‘Andinita’ in SIT were obtained. The best results were achieved with immersions every four hours, averaging five to seven microtubers per plant (approximately 600 microtubers per culture vessel, with sizes between 4 and 16 mm, with an average of 3 g fresh weight, which ensured budding efficiency and allow direct field planting. This result constitutes the first report of the use of SIT for propagation of potatoes in Venezuela. This is a new possibility to use SIT in other varieties. Key words: shoot tip, immersion frequency, seed

  13. Quality characteristics of soybean pasted (Doenjang) manufactured with 2 soybean mutant lines derived from cv. baekwon

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Jun; Kang, Si Yong; Choi, Hong Il; Kim, Jin Baek [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2016-11-15

    In order to identification of the possibility of manufacturing soybean paste (doenjang) with soybean mutant lines induced from gamma-ray mutagenesis, this study was performed to investigate the quality characteristics of doenjang using two soybean mutant lines, Baekwon-1 (BW-1) and Baekwon-2 (BW-2) and their original cultivar (cv. Baekwon, BW) for 8 weeks. The BW and two mutant lines (BW-1 and BW-2) were showed higher content of amino type nitrogen than control (cv. Taegwang). The pH decreased and the titratable acidity increased all the samples during aging period. The lightness, redness and yellowness of doenjang were the lowest in BW. Total free sugar content of doenjang was the highest in control (10.43%) after 4 weeks and composed mainly fructose and glucose. The order of the free amino acid content was Glutamic acid>Leucine>Lysine>Phenylalanine>Aspartic acid in control, Glutamic acid>Leucine >Arginine>Lysine>Phenylalanine in BW, Glutamic acid>Lysine>Phenylalanine>Aspartic acid>Valine in BW-1 and Glutamic acid>Arginine>Lysine>Phenylalanine>Aspartic acid in BW-2, respectively. Our results showed that it is possible to increase the quality of doenjang using soybean mutant lines in manufacturing soybean paste.

  14. Heliconia cv. Golden Torch cultivated under different irrigation depths in protected environment

    Directory of Open Access Journals (Sweden)

    Alcilane Arnaldo Silva

    2018-04-01

    Full Text Available The genus Heliconia is commercially detached by the exotic appearance of the inflorescences but is susceptible to lack of moisture in the soil, being necessary the irrigation management. In this sense, the objective was to evaluate the effect of different irrigation levels on the plant growth and productive characters of Heliconia psittacorum cv. Golden Torch cultivated in vase. The experiment was conducted from March to October 2014, in a randomized blocks design. Five treatments corresponding to the different irrigation levels were used [50, 75, 100, 125 and 150% of the evaporation measured in Class A (ECA] with four replicates and two plants per replicate. The following evaluations were carried out: number of days for the emergence of the first tiller, number of days for the emergence of the first inflorescence, number of days for the inflorescence harvest, crop cycle, diameter of the flower stem, length of the flower stem, inflorescence length, plant high, number of tillers and productivity of flower stems. Chlorophyll and leaf area measurements were performed. The irrigation levels tested significantly influenced the number of days for the first inflorescence harvest, length of the flower stem and inflorescence length. The irrigation level of 150% ECA provided better results for the length of the flower stem, inflorescence length and for leaf area but without differences from 75%, 100% and 125% ECA. Thus, for the cultivation of the heliconia cv. Golden Torch in pot can be recommended the level corresponding from 75% to 150% ECA.

  15. Storage and methyl jasmonate in postharvest conservation of roses cv. Avalanche

    Directory of Open Access Journals (Sweden)

    Elka Fabiana Aparecida Almeida

    2017-07-01

    Full Text Available The use of methyl jasmonate has demonstrated its efficiency to extend the vase life of cut flowers. The objective of this study was to evaluate the effect of methyl jasmonate associated with storage at low temperatures on the postharvest quality of Rosa cv. Avalanche stems. The treatments consisted of 125, 250, 500 and 1000 μM of methyl jasmonate, besides the control with distilled water. The flower buds were sprayed with 4 mL of the solution, according to the treatments, and then kept in a cold chamber (1 °C for periods of 2 and 6 days. Subsequently, the stems were taken to the postharvest laboratory at a temperature of 16 °C. Better quality, higher fresh weight and water absorption were observed in flower stems stored for 2 days. The application of methyl jasmonate caused less turgescence and greater darkening of roses. It was possible to conclude that two days is the best storage time at 1 °C and the use of methyl jasmonate does not maintain the quality of roses cv. Avalanche after harvest.

  16. a Fast Segmentation Algorithm for C-V Model Based on Exponential Image Sequence Generation

    Science.gov (United States)

    Hu, J.; Lu, L.; Xu, J.; Zhang, J.

    2017-09-01

    For the island coastline segmentation, a fast segmentation algorithm for C-V model method based on exponential image sequence generation is proposed in this paper. The exponential multi-scale C-V model with level set inheritance and boundary inheritance is developed. The main research contributions are as follows: 1) the problems of the "holes" and "gaps" are solved when extraction coastline through the small scale shrinkage, low-pass filtering and area sorting of region. 2) the initial value of SDF (Signal Distance Function) and the level set are given by Otsu segmentation based on the difference of reflection SAR on land and sea, which are finely close to the coastline. 3) the computational complexity of continuous transition are successfully reduced between the different scales by the SDF and of level set inheritance. Experiment results show that the method accelerates the acquisition of initial level set formation, shortens the time of the extraction of coastline, at the same time, removes the non-coastline body part and improves the identification precision of the main body coastline, which automates the process of coastline segmentation.

  17. Intestinal Permeability and Cellular Antioxidant Activity of Phenolic Compounds from Mango (Mangifera indica cv. Ataulfo) Peels.

    Science.gov (United States)

    Pacheco-Ordaz, Ramón; Antunes-Ricardo, Marilena; Gutiérrez-Uribe, Janet A; González-Aguilar, Gustavo A

    2018-02-08

    Mango ( Mangifera indica cv. Ataulfo) peel contains bound phenolics that may be released by alkaline or acid hydrolysis and may be converted into less complex molecules. Free phenolics from mango cv. Ataulfo peel were obtained using a methanolic extraction, and their cellular antioxidant activity (CAA) and permeability were compared to those obtained for bound phenolics released by alkaline or acid hydrolysis. Gallic acid was found as a simple phenolic acid after alkaline hydrolysis along with mangiferin isomers and quercetin as aglycone and glycosides. Only gallic acid, ethyl gallate, mangiferin, and quercetin were identified in the acid fraction. The acid and alkaline fractions showed the highest CAA (60.5% and 51.5%) when tested at 125 µg/mL. The value of the apparent permeability coefficient (Papp) across the Caco-2/HT-29 monolayer of gallic acid from the alkaline fraction was higher (2.61 × 10 -6 cm/s) than in the other fractions and similar to that obtained when tested pure (2.48 × 10 -6 cm/s). In conclusion, mango peels contain bound phenolic compounds that, after their release, have permeability similar to pure compounds and exert an important CAA. This finding can be applied in the development of nutraceuticals using this important by-product from the mango processing industry.

  18. Exogenous application of ascorbic acid alleviates chilling injury in apricot (Prunus armeniaca L. cv. Shahroudi flowers

    Directory of Open Access Journals (Sweden)

    Hassan Bayat

    2013-08-01

    Full Text Available One of the most important limiting factors in spread of apricot in Iran is late spring frost, which damages flower bud and decrease total yield of crop. It has been found that ascorbic acid (AA plays a beneficial role during plant response to chilling and freezing stresses. To evaluate the effects of AA on alleviating of cold stress, the flower buds of Prunus armeniaca L. cv. Shahroudi were sprayed at pink cluster stage with AS at 4 levels (0, 100, 200 and 300 mg. L-1 and were then exposed to artificial cold stress (4 h at –4 °C or without cold stress (+ 25°C. Experimental attributes including electrolyte leakage (EL of flower buds and percentage of damage of pistil, anthers and petals to temperature treatments were determined. The results showed that at - 4°C the lowest and highest percentage of damage and EL of flower buds were observed in application of 200 and 0 mg. L-1 AA, respectively. The highest and lowest percentage of damage of flower organs and EL were obtained in application of 300 and 200 mg. L-1 AA, respectively at + 25 °C. Based on the results of this experiment, AA alleviates the negative effect of cold stress on EL and flower organ damages in apricot cv. Shahroudi, depending on the concentrations of AA used.

  19. C-V characterization of Schottky- and MIS-gate SiGe/Si HEMT structures

    International Nuclear Information System (INIS)

    Onojima, Norio; Kasamatsu, Akihumi; Hirose, Nobumitsu; Mimura, Takashi; Matsui, Toshiaki

    2008-01-01

    Electrical properties of Schottky- and metal-insulator-semiconductor (MIS)-gate SiGe/Si high electron mobility transistors (HEMTs) were investigated with capacitance-voltage (C-V) measurements. The MIS-gate HEMT structure was fabricated using a SiN gate insulator formed by catalytic chemical vapor deposition (Cat-CVD). The Cat-CVD SiN thin film (5 nm) was found to be an effective gate insulator with good gate controllability and dielectric properties. We previously investigated device characteristics of sub-100-nm-gate-length Schottky- and MIS-gate HEMTs, and reported that the MIS-gate device had larger maximum drain current density and transconductance (g m ) than the Schottky-gate device. The radio frequency (RF) measurement of the MIS-gate device, however, showed a relatively lower current gain cutoff frequency f T compared with that of the Schottky-gate device. In this study, C-V characterization of the MIS-gate HEMT structure demonstrated that two electron transport channels existed, one at the SiGe/Si buried channel and the other at the SiN/Si surface channel

  20. C-V characterization of Schottky- and MIS-gate SiGe/Si HEMT structures

    Energy Technology Data Exchange (ETDEWEB)

    Onojima, Norio [National Institute of Information and Communications Technology (NICT), Koganei, Tokyo 184-8795 (Japan)], E-mail: nonojima@nict.go.jp; Kasamatsu, Akihumi; Hirose, Nobumitsu [National Institute of Information and Communications Technology (NICT), Koganei, Tokyo 184-8795 (Japan); Mimura, Takashi [National Institute of Information and Communications Technology (NICT), Koganei, Tokyo 184-8795 (Japan); Fujitsu Laboratories Ltd., Atsugi, Kanagawa 243-0197 (Japan); Matsui, Toshiaki [National Institute of Information and Communications Technology (NICT), Koganei, Tokyo 184-8795 (Japan)

    2008-07-30

    Electrical properties of Schottky- and metal-insulator-semiconductor (MIS)-gate SiGe/Si high electron mobility transistors (HEMTs) were investigated with capacitance-voltage (C-V) measurements. The MIS-gate HEMT structure was fabricated using a SiN gate insulator formed by catalytic chemical vapor deposition (Cat-CVD). The Cat-CVD SiN thin film (5 nm) was found to be an effective gate insulator with good gate controllability and dielectric properties. We previously investigated device characteristics of sub-100-nm-gate-length Schottky- and MIS-gate HEMTs, and reported that the MIS-gate device had larger maximum drain current density and transconductance (g{sub m}) than the Schottky-gate device. The radio frequency (RF) measurement of the MIS-gate device, however, showed a relatively lower current gain cutoff frequency f{sub T} compared with that of the Schottky-gate device. In this study, C-V characterization of the MIS-gate HEMT structure demonstrated that two electron transport channels existed, one at the SiGe/Si buried channel and the other at the SiN/Si surface channel.