176 research outputs found

    Analysis of surface roughness wake fields and longitudinal phase space in a linear electron accelerator

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    Problematizações das práticas psi : articulações com o pensamento foucaultiano

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    A problematização das práticas de intervenção na área psi tem sido orientada, muitas vezes, por alguns conceitos foucaultianos como poder, saber e regimes de verdade e tem introduzido questões diferenciadas em relação àquelas que tradicionalmente tem-se caracterizado como uma compreensão do que são as práticas psicológicas. Se por um lado essas reflexões passam por uma desacomodação produzidas pelo olhar foucaultiano, por outro lado, esse incômodo é suscitado pelas práticas psicológicas tradicionais que desfrutam de um estatuto de legitimidade. Esses questionamentos instigam o pensar sobre deslocamentos nas formas de intervenção e compreensão das práticas psi.The problematization of the practices of intervention in Psychology has been helped by foucauldian concepts such as power, knowledge, and truth regimes. These concepts have altered the questions which have traditionally characterized views of psychological practices. However, such analysis has been accused of focusing only on the condition of visibility of power relations and modes of production of truth regimes, instead of instituting new forms of action or intervention. In this article we aim to produce a space for new links between foucauldian thought and current ways of conceiving the interventions in the psychology field

    Intellectual property as complex innovation projects component

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    The materials presented the possibilities development of intellectual property complex innovation projects modern highly effective science-based problems of improving the use of wastes of different industries on a complex enterprise that can provide all its energy needs alone. Some features of the possibilities of solving evidence-based problems of development of mechanisms for identifying syner-gistic processes, their scientific justification improving the use of wastes of different industries on a complex enterprise. The problem of wastes utilization and recycling is present as complex synergetic processes research and analysis of energy- and resource saving process-es for treatment of polymer wastes of various origin. The research focused on the study of issues such as the development of models of waste-modifying polymer. The investigation are focused in researching such problems as selection of scientific based methods of wastes to be utilized or recycled; the development of appropriated process flow sheets and choice of modifications additives and equipment for polymers waste recycling. The choice of appropriate plants with selected energy resources is very important for projects realization

    Potential applications of the dielectric wakefield accelerators in the SINBAD facility at DESY

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    Short, high-brightness relativistic electron bunches can drive ultra-high wakefields in the dielectric wakefield accelerators (DWFAs). This effect can be used to generate high power THz coherent Cherenkov radiation, accelerate a witness bunch with gradient two or three orders of magnitude larger than that in the conventional RF linear accelerators, introduce energy modulation within the driving bunch itself, etc. The paper studies potential applications of the DWFAs in the SINBAD facility at DESY. The simulations show that the ultra-short relativistic bunches from the SINBAD injector ARES can excite accelerating wakefields with peak amplitudes as high as GV/m at THz frequencies in proper DWFA structures. In addition, it illustrates that the DWFA structure can serve as a dechirper to compensate the correlated energy spread of the bunches accelerated by the laser plasma wakefield accelerator

    Impact of the Wiggler Coherent Synchrotron Radiation Impedance on the Beam Instability

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    Coherent Synchrotron Radiation (CSR) can play an important role by not only increasing the energy spread and emittance of a beam, but also leading to a potential instability. Previous studies of the CSR induced longitudinal instability were carried out for the CSR impedance due to dipole magnets. However, many storage rings include long wigglers where a large fraction of the synchrotron radiation is emitted. This includes high-luminosity factories such as DAPHNE, PEP-II, KEK-B, and CESR-C as well as the damping rings of future linear colliders. In this paper, the instability due to the CSR impedance from a wiggler is studied assuming a large wiggler parameter KK. The primary consideration is a low frequency microwave-like instability, which arises near the pipe cut-off frequency. Detailed results are presented on the growth rate and threshold for the damping rings of several linear collider designs. Finally, the optimization of the relative fraction of damping due to the wiggler systems is discussed for the damping rings.Comment: 10 pages, 7 figure

    Optical Klystron Enhancement to SASE X-ray FELs

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    The optical klystron enhancement to self-amplified spontaneous emission (SASE) free electron lasers (FELs) is studied in theory and in simulations. In contrast to a seeded FEL, the optical klystron gain in a SASE FEL is not sensitive to any phase mismatch between the radiation and the microbunched electron beam. The FEL performance with the addition of four optical klystrons located at the undulator long breaks in the Linac Coherent Light Source (LCLS) shows significant improvement if the uncorrelated energy spread at the undulator entrance can be controlled to a very small level. In addition, FEL saturation at shorter x-ray wavelengths (around 1.0 \AA) within the LCLS undulator length becomes possible. We also discuss the application of the optical klystron in a compact x-ray FEL design that employs relatively low electron beam energy together with a short-period undulator.Comment: 17 pages, 8 figures, submitted to Phys. Rev. ST Accel. Beam

    Measurement with beam of the deflecting higher order modes in the TTF superconducting cavities

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    This paper reports on recent beam measurements of higher order modes in the TESLA Test Facility (TTF) accelerating modules. Using bunch trains of about 0.5 ms with 54MHz bunch repetition and up to 90% modulated intensity, transverse higher order modes are resonantly excited when the beam is offset and their frequency on resonance with the modulation frequency. With this method, the trapped modes can be excited and their counteraction on the beam observed on a wide-band BPM downstream of the module. Scanning the modulation frequency from 0 to 27MHz allows a systematic investigation of all possible dangerous modes in the modules
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